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21 pages, 1998 KiB  
Article
Analysis of Infection and Diffusion Coefficient in an SIR Model by Using Generalized Fractional Derivative
by Ibtehal Alazman, Manvendra Narayan Mishra, Badr Saad Alkahtani and Ravi Shanker Dubey
Fractal Fract. 2024, 8(9), 537; https://doi.org/10.3390/fractalfract8090537 (registering DOI) - 15 Sep 2024
Abstract
In this article, a diffusion component in an SIR model is introduced, and its impact is analyzed using fractional calculus. We have included the diffusion component in the SIR model. in order to illustrate the variations. Here, we have applied the general fractional [...] Read more.
In this article, a diffusion component in an SIR model is introduced, and its impact is analyzed using fractional calculus. We have included the diffusion component in the SIR model. in order to illustrate the variations. Here, we have applied the general fractional derivative to analyze the impact. The Laplace decomposition technique is employed to obtain the numerical outcomes of the model. In order to observe the effect of the diffusion component in the SIR model, graphical solutions are also displayed. Full article
(This article belongs to the Special Issue Advances in Fractional Modeling and Computation)
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Figure 1

Figure 1
<p>Graph of susceptible against time t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Caputo–Fabrizio case.</p>
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<p>Graph of infected against time t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Caputo–Fabrizio case.</p>
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<p>Graph of recovered against time t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Caputo–Fabrizio case.</p>
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<p>Graph of susceptible with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Riemann–Liouville’s case.</p>
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<p>Graph of infected with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Riemann–Liouville’s case.</p>
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<p>Graph of recovered with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in Riemann–Liouville’s case.</p>
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<p>Graph of susceptible with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in ABC case.</p>
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<p>Graph of infected with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in ABC case.</p>
Full article ">Figure 9
<p>Graph of recovered with respect to t, for <math display="inline"><semantics> <mi>τ</mi> </semantics></math> = 0.7 and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> in ABC case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for x=0.15, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> in CF case.</p>
Full article ">Figure 11
<p>Graph of susceptible, infected and recovered class with respect to t, for x=0.15, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> in RL case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for x=0.15, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> in ABC case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.01 in CF case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.001 in CF case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.0001 in CF case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.01 in RL case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.001 in RL case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.0001 in RL case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.01 in ABC case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.001 in ABC case.</p>
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<p>Graph of susceptible, infected and recovered class with respect to t, for diffusion coefficient 0.0001 in ABC case.</p>
Full article ">Figure 22
<p>Graph of susceptible with CF, RL and ABC derivative for <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 23
<p>Graph of infected with CF, RL and ABC derivative for <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 24
<p>Graph of recovered with CF, RL and ABC derivative for <math display="inline"><semantics> <mrow> <mi>τ</mi> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.001</mn> </mrow> </semantics></math>.</p>
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39 pages, 7466 KiB  
Article
Evaluation of Adsorption Ability of Lewatit® VP OC 1065 and Diaion™ CR20 Ion Exchangers for Heavy Metals with Particular Consideration of Palladium(II) and Copper(II)
by Anna Wołowicz and Zbigniew Hubicki
Molecules 2024, 29(18), 4386; https://doi.org/10.3390/molecules29184386 (registering DOI) - 15 Sep 2024
Abstract
The adsorption capacities of ion exchangers with the primary amine (Lewatit® VP OC 1065) and polyamine (Diaion™ CR20) functional groups relative to Pd(II) and Cu(II) ions were tested in a batch system, taking into account the influence of the acid concentration (HCl: [...] Read more.
The adsorption capacities of ion exchangers with the primary amine (Lewatit® VP OC 1065) and polyamine (Diaion™ CR20) functional groups relative to Pd(II) and Cu(II) ions were tested in a batch system, taking into account the influence of the acid concentration (HCl: 0.1–6 mol/L; HCl-HNO3: 0.9–0.1 mol/L HCl—0.1–0.9 mol/L HNO3), phase contact time (1–240 min), initial concentration (10–1000 mg/L), agitation speed (120–180 rpm), bead size (0.385–1.2 mm), and temperature (293–333 K), as well as in a column system where the variable operating parameters were HCl and HNO3 concentrations. There were used the pseudo-first order, pseudo-second order, and intraparticle diffusion models to describe the kinetic studies and the Langmuir and Freundlich isotherm models to describe the equilibrium data to obtain better knowledge about the adsorption mechanism. The physicochemical properties of the ion exchangers were characterized by the nitrogen adsorption/desorption analyses, CHNS analysis, Fourier transform infrared spectroscopy, the sieve analysis, and points of zero charge measurements. As it was found, Lewatit® VP OC 1065 exhibited a better ability to remove Pd(II) than Diaion™ CR20, and the adsorption ability series for heavy metals was as follows: Pd(II) >> Zn(II) ≈ Ni(II) >> Cu(II). The optimal experimental conditions for Pd(II) sorption were 0.1 mol/L HCl, agitation speed 180 rpm, temperature 293 K, and bead size fraction 0.43 mm ≤ f3 < 0.6 mm for Diaion™ CR20 and 0.315–1.25 mm for Lewatit® VP OC 1065. The maximum adsorption capacities were 289.68 mg/g for Lewatit® VP OC 1065 and 208.20 mg/g for Diaion™ CR20. The greatest adsorption ability of Lewatit® VP OC 1065 for Pd(II) was also demonstrated in the column studies. The working ion exchange in the 0.1 mol/L HCl system was 0.1050 g/mL, much higher compared to Diaion™ CR20 (0.0545 g/mL). The best desorption yields of %D1 = 23.77% for Diaion™ CR20 and 33.57% for Lewatit® VP OC 1065 were obtained using the 2 mol/L NH3·H2O solution. Full article
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Figure 1

Figure 1
<p>Palladium and copper application, impact on the body, dietary sources and prices, supply, demand, and uses.</p>
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<p>Palladium and copper application, impact on the body, dietary sources and prices, supply, demand, and uses.</p>
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<p>(<b>a</b>) Percentage content of elements and (<b>b</b>) comparison of <span class="html-italic">pH<sub>PZC</sub></span> values in/for Lewatit<sup>®</sup> VP OC 1065 and Diaion™ CR20 ion exchange resins.</p>
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<p>Low-temperature adsorption/desorption nitrogen isotherm of (<b>a</b>) Diaion™ CR20 and (<b>b</b>) Lewatit<sup>®</sup> VP OC 1065 ion exchangers.</p>
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<p>ATR/FT-IR spectra of (<b>a</b>) Diaion™ CR20 and (<b>b</b>) Lewatit<sup>®</sup> VP OC 1065 before and after loading with Pd(II) and Cu(II) ions.</p>
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<p>Comparison of M(II) sorption efficiency expressed in <span class="html-italic">q<sub>t</sub></span> values for Diaion™ CR20 (<b>a</b>,<b>c</b>,<b>e</b>,<b>g</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>,<b>d</b>,<b>f</b>,<b>h</b>).</p>
Full article ">Figure 5 Cont.
<p>Comparison of M(II) sorption efficiency expressed in <span class="html-italic">q<sub>t</sub></span> values for Diaion™ CR20 (<b>a</b>,<b>c</b>,<b>e</b>,<b>g</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>,<b>d</b>,<b>f</b>,<b>h</b>).</p>
Full article ">Figure 6
<p>Effects of contact time and agitation speed on the Pd(II) adsorption on Diaion™ CR20 (<b>a</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>).</p>
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<p>Effects of contact time and the initial Pd(II) concentration on Pd(II) adsorption on Diaion™ CR20 (<b>a</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>).</p>
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<p>Effects of contact time and bead size of ion exchangers (f5 &lt; 0.385 mm; 0.385 mm ≤ f4 &lt; 0.43 mm; 0.43 mm ≤ f3 &lt; 0.6 mm; 0.6 mm ≤ f2 &lt; 0.75 mm; 0.75 mm ≤ f1 &lt; 1.2 mm) on Pd(II) adsorption on Diaion™ CR20 (<b>a</b>,<b>c</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>,<b>d</b>).</p>
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<p>Effects of contact time and temperature on the Pd(II) adsorption on Diaion™ CR20 (<b>a</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>).</p>
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<p>Effects of contact time and initial concentration (<b>a</b>), agitation speed (<b>b</b>), bead size of ion exchanger (f5 &lt; 0.385 mm; 0.385 mm ≤ f4 &lt; 0.43 mm; 0.43 mm ≤ f3 &lt; 0.6 mm; 0.6 mm ≤ f2 &lt; 0.75 mm; 0.75 mm ≤ f1 &lt; 1.2 mm), (<b>c</b>) and temperature (<b>d</b>) on Cu(II) adsorption on Diaion™ CR20 from 6 mol/L HCl—10 (<b>a</b>) or 50 mg Cu(II)/L (<b>a</b>–<b>d</b>).</p>
Full article ">Figure 11
<p>PFO (<b>a</b>,<b>b</b>), PSO (<b>c</b>,<b>d</b>), and IPD (<b>e</b>,<b>f</b>) plots and fitting of the experimental data of Pd(II) ion adsorption on Diaion™ CR20 (<b>g</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>h</b>).</p>
Full article ">Figure 11 Cont.
<p>PFO (<b>a</b>,<b>b</b>), PSO (<b>c</b>,<b>d</b>), and IPD (<b>e</b>,<b>f</b>) plots and fitting of the experimental data of Pd(II) ion adsorption on Diaion™ CR20 (<b>g</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>h</b>).</p>
Full article ">Figure 12
<p>Experimental points and fitting of the Langmuir and Freundlich isotherms for Pd(II) (<b>a</b>,<b>c</b>) and Cu(II) (<b>b</b>,<b>d</b>) ion adsorption on the Diaion™ CR20 (<b>a</b>,<b>b</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>c</b>,<b>d</b>).</p>
Full article ">Figure 13
<p>Comparison of the breakthrough curves of Pd(II) ion adsorption on Lewatit<sup>®</sup> VP OC 1065 (<b>a</b>,<b>c</b>) and Diaion™ CR20 (<b>b</b>,<b>d</b>) from the chloride 0.1–6 mol/L HCl—100 mg Pd(II)/L (<b>a</b>,<b>b</b>) and the chloride-nitrate(V) solutions 0.1–0.9 mol/L HCl—0.9–0.1 mol/L HNO<sub>3</sub>—100 mg Pd(II)/L (<b>c</b>,<b>d</b>).</p>
Full article ">Figure 13 Cont.
<p>Comparison of the breakthrough curves of Pd(II) ion adsorption on Lewatit<sup>®</sup> VP OC 1065 (<b>a</b>,<b>c</b>) and Diaion™ CR20 (<b>b</b>,<b>d</b>) from the chloride 0.1–6 mol/L HCl—100 mg Pd(II)/L (<b>a</b>,<b>b</b>) and the chloride-nitrate(V) solutions 0.1–0.9 mol/L HCl—0.9–0.1 mol/L HNO<sub>3</sub>—100 mg Pd(II)/L (<b>c</b>,<b>d</b>).</p>
Full article ">Figure 14
<p>Comparison of the adsorption (%<span class="html-italic">S</span>) and desorption (%<span class="html-italic">D</span>) efficiency of Pd(II) ions on/from (<b>a</b>) Diaion™ CR20, (<b>b</b>) Lewatit<sup>®</sup> VP OC 1065 ion exchangers in three adsorption–desorption cycles using ammonium hydroxide solutions.</p>
Full article ">Figure 15
<p>Effects of simultaneous presence of Pd(II) and Cu(II) ions in the solutions on their sorption yield on the Diaion™ CR20 and Lewatit<sup>®</sup> VP OC 1065 ion exchangers from the S (single) and B (bi-component) solutions.</p>
Full article ">Figure 16
<p>Diaion™ CR20 (<b>a</b>,<b>c</b>) and Lewatit<sup>®</sup> VP OC 1065 (<b>b</b>,<b>d</b>) ion exchange resins beads before the adsorption (<b>a</b>,<b>b</b>) (magnification 5×) and after the Cu(II) and Pd(II) adsorption (<b>c</b>,<b>d</b>) (magnification 2.5×).</p>
Full article ">
18 pages, 2859 KiB  
Article
Forecasting Carbon Sequestration Potential in China’s Grasslands by a Grey Model with Fractional-Order Accumulation
by Lei Wu, Chun Wang, Chuanhui Wang and Weifeng Gong
Fractal Fract. 2024, 8(9), 536; https://doi.org/10.3390/fractalfract8090536 (registering DOI) - 14 Sep 2024
Viewed by 270
Abstract
This study aims to predict the carbon sequestration capacity of Chinese grasslands to address climate change and achieve carbon neutrality goals. Grassland carbon sequestration is a crucial part of the global carbon cycle. However, its capacity is significantly impacted by climate change and [...] Read more.
This study aims to predict the carbon sequestration capacity of Chinese grasslands to address climate change and achieve carbon neutrality goals. Grassland carbon sequestration is a crucial part of the global carbon cycle. However, its capacity is significantly impacted by climate change and human activities, making its dynamic changes complex and challenging to predict. This study adopts a fractional-order accumulation grey model, using 11 provinces in China as samples, to analyze and forecast grassland carbon sequestration. The study finds significant differences in grassland carbon sequestration trends across the sample regions. The carbon sequestration capacity of the grasslands in Xizang (Tibet) and Heilongjiang province is increasing, while it is decreasing in other provinces. The varying prediction results are influenced not only by regional climatic and natural conditions, but also by human interventions such as overgrazing, irrational reclamation, excessive mineral resource exploitation, and increased tourism development. Therefore, more region-specific grassland management and protection strategies should be formulated to enhance the carbon sequestration capacity of grasslands and promote the sustainable development of ecosystems. The significance of this study lies not only in providing scientific guidance for the protection and sustainable management of Chinese grasslands, but also in contributing theoretical and practical insights into global carbon sequestration strategies. Full article
(This article belongs to the Special Issue Applications of Fractional-Order Grey Models)
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Figure 1
<p>Influence factors of grasslands carbon sequestration.</p>
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<p>Distribution map of sample provinces (rectangle block).</p>
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<p>Prediction results for Xizang (Tibet) and Qinghai Province.</p>
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<p>Prediction results for Neimongolia–Ningxia-Gansu grassland region.</p>
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<p>Prediction results for Xinjiang grassland region.</p>
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<p>Prediction results for Sichuan and Yunnan Provinces.</p>
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<p>Prediction results for Heilongjiang Province.</p>
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25 pages, 1082 KiB  
Article
On the Existence, Uniqueness and a Numerical Approach to the Solution of Fractional Cauchy–Euler Equation
by Nazim I. Mahmudov, Suzan Cival Buranay and Mtema James Chin
Axioms 2024, 13(9), 627; https://doi.org/10.3390/axioms13090627 - 12 Sep 2024
Viewed by 175
Abstract
In this research paper, we consider a model of the fractional Cauchy–Euler-type equation, where the fractional derivative operator is the Caputo with order 0<α<2. The problem also constitutes a class of examples of the Cauchy problem of the [...] Read more.
In this research paper, we consider a model of the fractional Cauchy–Euler-type equation, where the fractional derivative operator is the Caputo with order 0<α<2. The problem also constitutes a class of examples of the Cauchy problem of the Bagley–Torvik equation with variable coefficients. For proving the existence and uniqueness of the solution of the given problem, the contraction mapping principle is utilized. Furthermore, a numerical method and an algorithm are developed for obtaining the approximate solution. Also, convergence analyses are studied, and simulations on some test problems are given. It is shown that the proposed method and the algorithm are easy to implement on a computer and efficient in computational time and storage. Full article
(This article belongs to the Special Issue Applied Mathematics and Numerical Analysis: Theory and Applications)
19 pages, 7427 KiB  
Article
The Influence of the Structural Architecture on the Swelling Kinetics and the Network Behavior of Sodium-Alginate-Based Hydrogels Cross-Linked with Ionizing Radiation
by Ion Călina, Maria Demeter, Gabriela Crăciun, Anca Scărișoreanu and Elena Mănăilă
Gels 2024, 10(9), 588; https://doi.org/10.3390/gels10090588 - 12 Sep 2024
Viewed by 378
Abstract
The present work discusses the influence of the structural architecture of sodium alginate–co-acrylic acid–poly(ethylene) oxide hydrogels, crosslinked through electron beam (e-beam) radiation processing. The most important properties of the hydrogels were studied in detail to identify a correlation between the architecture of the [...] Read more.
The present work discusses the influence of the structural architecture of sodium alginate–co-acrylic acid–poly(ethylene) oxide hydrogels, crosslinked through electron beam (e-beam) radiation processing. The most important properties of the hydrogels were studied in detail to identify a correlation between the architecture of the hydrogels and their properties. Furthermore, the effect of sodium alginate (NaAlg) concentration, the amounts of the polymer blend, and the size of the samples on hydrogel properties were investigated. The results show that the hydrogels cross-linked (0.5% and 1% NaAlg) with 12.5 kGy exhibit improved physicochemical properties. High gel fraction levels (exceeding 83.5–93.7%) were achieved. Smaller hydrogel diameter (7 mm) contributed to a maximum swelling rate and degree of 20.440%. The hydrogel network was dependent on the hydrogels’ diameter and the amount of polymer blend used. The hydrogels best suited the first-order rate constants and exhibited a non-Fickian diffusion character with diffusion exponent values greater than 0.5. This study indicates that the cross-linked hydrogel has good properties, particularly because of its high degree of swelling and extensive stability (more than 180 h) in water. These findings show that hydrogels can be effectively applied to the purification of water contaminated with metals, dyes, or even pharmaceuticals, as well as materials with a gradual release of bioactive chemicals and water retention. Full article
(This article belongs to the Special Issue Polymeric Hydrogels for Biomedical Application)
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Figure 1

Figure 1
<p>Representative images of hydrogels: (<b>A</b>) after e-beam irradiation at room temperature (25 °C)<span class="html-italic">;</span> (<b>B</b>); after being stored for 24 h at ambient temperature; (<b>C</b>) cut and immersed in ethanol for 24 h; (<b>D</b>) cut into discs at 15, 10, and 7 mm in diameter.</p>
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<p>The effect of NaAlg concentration, polymer volume, and hydrogel size on the gel fraction.</p>
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<p>The cross-links density of the hydrogel samples.</p>
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<p>Relationship between the amount of polymer solution and swelling degree of hydrogels at different sizes: (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>The swelling degree values of the hydrogels based on size: (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>The hydrogel samples swelled at equilibrium.</p>
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<p>The first-order swelling kinetics of cross-linked hydrogels: (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>The second-order swelling kinetics of cross-linked hydrogels: (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>The swelling kinetic curve of the cross-linked hydrogels (ln F vs. ln t): (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>The swelling kinetic curve of the cross-linked hydrogels (F vs. t<sup>0.5</sup>): (<b>A</b>) for hydrogels with a NaAlg concentration of 0.5% and (<b>B</b>) for hydrogels with a NaAlg concentration of 1%.</p>
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<p>FTIR spectra of (<b>a</b>) native polymers (NaAlg, AA/ and PEO) and (<b>b</b>) I (0.5% NaAlg) and II (1% NaAlg) hydrogels with a diameter of 7 mm.</p>
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<p>SEM images of the (<b>a</b>) I<sub>7</sub>_20 mL, (<b>b</b>) I<sub>7</sub>_40 mL, (<b>c</b>) II<sub>7</sub>_20 mL, and (<b>d</b>) II<sub>7</sub>_40 mL hydrogels at 50× magnification. Scale bars indicate 1 mm.</p>
Full article ">
14 pages, 3525 KiB  
Article
Restoring Model of a Pneumatic Artificial Muscle with Structure Parameters: Analysis and Identification
by Minh Ky Nguyen, Van Chon Trinh, Ngoc Yen Phuong Vo and Thanh Danh Le
Actuators 2024, 13(9), 355; https://doi.org/10.3390/act13090355 - 12 Sep 2024
Viewed by 176
Abstract
This paper will develop the restoring model of a commercial pneumatic artificial muscle (PAM) based on a McKibben structure, which comprises an elastic element connected with a viscoelastic element in parallel. The elastic element is generated by compressed air inside the rubber bellow; [...] Read more.
This paper will develop the restoring model of a commercial pneumatic artificial muscle (PAM) based on a McKibben structure, which comprises an elastic element connected with a viscoelastic element in parallel. The elastic element is generated by compressed air inside the rubber bellow; meanwhile, the viscoelasticity is affected by the rubber material. In particular, the viscoelastic property of the rubber material is proposed based on the Maxwell model. Instead of derivative of integer orders, an equation of motion of the fractional model is introduced to better capture the amplitude- and frequency-dependent property of the viscoelasticity of the PAM. The equation expressing the hysteresis loop due to the viscoelasticity of the PAM material will then be analyzed and built. A water cycle algorithm is employed to determine the optimal set of the proposed model. To evaluate the effectiveness of the proposed model, a comparison between the simulation calculated from the proposed model and experimental data is considered under harmonic force excitation. This study’s results give potential insight into the field of system dynamic analysis with the elastic element being PAM. Full article
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<p>Physical structure of PAM (<b>a</b>); diagram of fractional Maxwell model (<b>b</b>).</p>
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<p>Working states of the PAM.</p>
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<p>Hysteresis curve of fractional Maxwell model.</p>
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<p>Hydrological cycle.</p>
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<p>The schematic diagram of the stream to river and river to sea.</p>
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<p>Experimental setup (<b>a</b>); diagram of the apparatus (<b>b</b>): 1—Motor; 2—Compressor; 3—Filter; 4—Air reservoir; 5—Pressure regulator; 6—On–off valve; 7—Pressure gauge; 8—Safety valve; 9—Pressure sensor; 10—PAM; 11—Loadcell; 12—Position sensor; 13—Base; 14—Coupling; 15—Pneumatic cylinder; 16—Proportional valve; 17—NI card 6221; 18—Computer.</p>
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<p>Measured signals versus time: (<b>a</b>) pressure; (<b>b</b>) position.</p>
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<p>Comparison between the experimental and approximate curves.</p>
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<p>Comparison between the simulation and experiment (detailed annotation of the line types is presented in top-left corner panel).</p>
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<p>Convergence of the cost function.</p>
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<p>Comparison of experimented and calculated hysteresis loops with frequency of 3.5 Hz and various force amplitudes: (<b>a</b>) 95 N; (<b>b</b>) 110 N; (<b>c</b>) 122 N; (<b>d</b>) 148 N.</p>
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<p>Comparison of experimented and calculated hysteresis loops with force amplitude of 125 N and various frequencies: (<b>a</b>) 3.5 Hz (<b>b</b>) 4.5 Hz; (<b>c</b>) 7.5 Hz; (<b>d</b>) 8.5 Hz.</p>
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18 pages, 14800 KiB  
Article
Fixed-Time Robust Fractional-Order Sliding Mode Control Strategy for Grid-Connected Inverters Based on Weighted Average Current
by Wenbin Song, Yanfei Dong, Guofeng He and Zichun Zhou
Energies 2024, 17(18), 4577; https://doi.org/10.3390/en17184577 - 12 Sep 2024
Viewed by 202
Abstract
To address the issues of high computational load and slow dynamic performance in traditional fractional-order sliding mode control for LCL-type grid-connected inverters, this paper proposes a fixed-time robust fractional-order sliding mode control strategy based on weighted average current control. Firstly, the weighted average [...] Read more.
To address the issues of high computational load and slow dynamic performance in traditional fractional-order sliding mode control for LCL-type grid-connected inverters, this paper proposes a fixed-time robust fractional-order sliding mode control strategy based on weighted average current control. Firstly, the weighted average current control (WACC) is used to reduce the third-order LCL filter to the first order, which simplifies the system model; secondly, in order to suppress the disturbance caused by the filter parameter perturbation to the weighted average current accuracy, a fixed-time disturbance observer (FTDO) is used to quickly estimate the disturbance caused by the filter parameter perturbation in a fixed time, so as to improve the anti-interference ability of the system; moreover, a fixed-time fractional-order sliding mode controller (FTFOSMC) is designed to achieve rapid tracking of the incoming reference current, and the stability of the proposed control strategy is confirmed by the strict Lyapunov method, which proves that the upper bound of the stability time is independent of the initial state of the system. Finally, simulation and experimental results show that the proposed method has better steady-state performance and a higher dynamic performance. Full article
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<p>Topology of LCL grid-tied inverter.</p>
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<p>Amplitude frequency characteristic curves of <math display="inline"><semantics> <mrow> <msub> <mi>G</mi> <mrow> <msub> <mi>u</mi> <mi>j</mi> </msub> <mo>−</mo> <msub> <mi>i</mi> <mrow> <mn>1</mn> <mi>j</mi> </mrow> </msub> </mrow> </msub> </mrow> </semantics></math>, <math display="inline"><semantics> <mrow> <msub> <mi>G</mi> <mrow> <msub> <mi>u</mi> <mi>j</mi> </msub> <mo>−</mo> <msub> <mi>i</mi> <mrow> <mn>2</mn> <mi>j</mi> </mrow> </msub> </mrow> </msub> </mrow> </semantics></math>.</p>
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<p>This amplitude–frequency characteristic curves.</p>
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<p>A diagram of the proposed control strategy.</p>
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<p>The simulation results of the grid current in steady state: (<b>a</b>) the traditional controller; (<b>b</b>) the traditional controller’s THD; (<b>c</b>) the proposed controller; (<b>d</b>) the proposed controller’s THD.</p>
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<p>The simulation results of the grid current with parameter mismatch: (<b>a</b>) the traditional controller; (<b>b</b>) the proposed controller.</p>
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<p>The simulation results of the current command changing the grid current: (<b>a</b>) the traditional controller; (<b>b</b>) the proposed controller.</p>
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<p>The simulation results of the current command changing the grid current: (<b>a</b>) the traditional controller; (<b>b</b>) the proposed controller.</p>
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<p>Simulation results under traditional FOSMC control: (<b>a</b>) grid voltage change; (<b>b</b>) grid current.</p>
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<p>Simulation results under the proposed controller: (<b>a</b>) grid voltage change; (<b>b</b>) grid current.</p>
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<p>dsPACE semi-physical simulation platform.</p>
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<p>The experimental results of the grid current under steady-state conditions: (<b>a</b>) the traditional controller; (<b>b</b>) the proposed controller.</p>
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<p>The experimental results of the grid current under dynamic conditions: (<b>a</b>) the traditional controller; (<b>b</b>) the proposed controller.</p>
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97 pages, 23005 KiB  
Article
Dealing with Stationary Sinusoidal Responses of Seven Types of Multi-Fractional Vibrators Using Multi-Fractional Phasor
by Ming Li
Symmetry 2024, 16(9), 1197; https://doi.org/10.3390/sym16091197 - 11 Sep 2024
Viewed by 444
Abstract
The novelty and main contributions of this paper are reflected in four aspects. First, we introduce multi-fractional phasor in Theorem 1. Second, we propose the motion phasor equations of seven types of multi-fractional vibrators in Theorems 2, 12, 22, 32, 43, 54, and [...] Read more.
The novelty and main contributions of this paper are reflected in four aspects. First, we introduce multi-fractional phasor in Theorem 1. Second, we propose the motion phasor equations of seven types of multi-fractional vibrators in Theorems 2, 12, 22, 32, 43, 54, and 65, respectively. Third, we present the analytical expressions of response phasors of seven types of multi-fractional vibrators in Theorems 10, 20, 30, 41, 52, 63, and 74, respectively. Fourth, we bring forward the analytical expressions of stationary sinusoidal responses of seven types of multi-fractional vibrators in Theorems 11, 21, 31, 42, 53, 64, and 75, respectively. In addition, by using multi-fractional phasor, we put forward the analytical expressions of vibration parameters (equivalent mass, equivalent damping, equivalent stiffness, equivalent damping ratio, equivalent damping free natural angular frequency, equivalent damped natural angular frequency, equivalent frequency ratio) and frequency transfer functions of seven types of multi-fractional vibrators. Demonstrations exhibit that the effects of multi-fractional orders on stationary sinusoidal responses of those multi-fractional vibrators are considerable. Full article
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Figure 1
<p>Plots of <italic>m</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>m</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>m</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>m</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>m</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>c</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>c</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>c</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>ζ</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ζ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>ζ</italic><sub>eq1</sub> for <italic>m</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ζ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Plots of <italic>ω</italic><sub>eqn1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqn1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
Full article ">Figure 4 Cont.
<p>Plots of <italic>ω</italic><sub>eqn1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqn1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>ω</italic><sub>eqd1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.4 (dot), 2.6 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqd1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>ω</italic><sub>eqd1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.4 (dot), 2.6 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqd1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>γ</italic><sub>eq1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>γ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>γ</italic><sub>eq1</sub> for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq1</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>γ</italic><sub>eq1</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of |<italic>H</italic><sub>1</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>1</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). |<italic>H</italic><sub>1</sub>(<italic>ω</italic>)| for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). |<italic>H</italic><sub>1</sub>(<italic>ω</italic>)| for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). |<italic>H</italic><sub>1</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>φ</italic><sub>1</sub>(<italic>ω</italic>) for <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>1</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>φ</italic><sub>1</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash). (<bold>c</bold>). <italic>φ</italic><sub>1</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>φ</italic><sub>1</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
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<p>Illustrations of <italic>x</italic><sub>1</sub>(<italic>t</italic>) for <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>1</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 1.5 (dot), 1.8 (dash). (<bold>b</bold>). <italic>x</italic><sub>1</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 2.2 (solid), 2.5 (dot), 2.8 (dash).</p>
Full article ">Figure 10
<p>Illustrations of <italic>x</italic><sub>1</sub>(<italic>t</italic>) for <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>1</sub>(<italic>t</italic>) when for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>b</bold>). <italic>x</italic><sub>1</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7).</p>
Full article ">Figure 11
<p>Plots of <italic>m</italic><sub>eq2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1. (<bold>a</bold>). <italic>m</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 11 Cont.
<p>Plots of <italic>m</italic><sub>eq2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1. (<bold>a</bold>). <italic>m</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>m</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 12
<p>Plots of <italic>c</italic><sub>eq2</sub> for <italic>c</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 12 Cont.
<p>Plots of <italic>c</italic><sub>eq2</sub> for <italic>c</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>c</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 13
<p>Plots of <italic>ζ</italic><sub>eq2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 13 Cont.
<p>Plots of <italic>ζ</italic><sub>eq2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ζ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 14
<p>Plots of <italic>ω</italic><sub>eqn2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 14 Cont.
<p>Plots of <italic>ω</italic><sub>eqn2</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqn2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 15
<p>Illustrations of <italic>ω</italic><sub>eqd2</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 15 Cont.
<p>Illustrations of <italic>ω</italic><sub>eqd2</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>ω</italic><sub>eqd2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 16
<p>Plots of <italic>γ</italic><sub>eq2</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 16 Cont.
<p>Plots of <italic>γ</italic><sub>eq2</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd2</sub> for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>γ</italic><sub>eq2</sub> when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 17
<p>Plots of |<italic>H</italic><sub>2</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>2</sub>(<italic>ω</italic>)| for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>2</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>2</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). |<italic>H</italic><sub>2</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 18
<p>Plots of <italic>φ</italic><sub>2</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>2</sub>(<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>2</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>2</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>d</bold>). <italic>φ</italic><sub>2</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 19
<p>Plots of <italic>x</italic><sub>2</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>2</sub>(<italic>t</italic>) for <italic>β</italic> = 0.3 (solid), 0.6 (dot), and 0.9 (dash). (<bold>b</bold>). <italic>x</italic><sub>2</sub>(<italic>t</italic>) for <italic>β</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash).</p>
Full article ">Figure 20
<p>Plots of <italic>x</italic><sub>2</sub>(<italic>t</italic>) when <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>2</sub>(<italic>t</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>b</bold>). <italic>x</italic><sub>2</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 21
<p>Plots of <italic>m</italic><sub>eq3</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1. (<bold>a</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>m</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>m</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>m</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 22
<p>Plots of <italic>c</italic><sub>eq3</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>c</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>c</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 22 Cont.
<p>Plots of <italic>c</italic><sub>eq3</sub> for <italic>m</italic> = 1 and <italic>c</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>c</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>c</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>c</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 23
<p>Plots of <italic>ζ</italic><sub>eq3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>ζ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>ζ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>ζ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 24
<p>Plots of <italic>ω</italic><sub>eqn3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>ω</italic><sub>eqn3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>ω</italic><sub>eqn3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 24 Cont.
<p>Plots of <italic>ω</italic><sub>eqn3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>ω</italic><sub>eqn3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>ω</italic><sub>eqn3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>ω</italic><sub>eqn3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 25
<p>Plots of <italic>ω</italic><sub>eqd3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>ω</italic><sub>eqd3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>ω</italic><sub>eqd3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 25 Cont.
<p>Plots of <italic>ω</italic><sub>eqd3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>ω</italic><sub>eqd3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>ω</italic><sub>eqd3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>ω</italic><sub>eqd3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 26
<p>Plots of <italic>γ</italic><sub>eq3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>γ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>γ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 26 Cont.
<p>Plots of <italic>γ</italic><sub>eq3</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>γ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>γ</italic><sub>eq3</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 27
<p>Plots of |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 27 Cont.
<p>Plots of |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.8 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). |<italic>H</italic><sub>3</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 28
<p>Plots of <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.5 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.5 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.5 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.5 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 28 Cont.
<p>Plots of <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq3</sub> with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.5 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.5 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.5 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>f</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.5 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>g</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>φ</italic><sub>3</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 29
<p>Plots of <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>β</italic> = 1, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>b</bold>). <italic>β</italic> = 1, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>c</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>d</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>e</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>f</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>g</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 29 Cont.
<p>Plots of <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>β</italic> = 1, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>b</bold>). <italic>β</italic> = 1, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>c</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>d</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>e</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>f</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>g</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 29 Cont.
<p>Plots of <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>β</italic> = 1, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>b</bold>). <italic>β</italic> = 1, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>c</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>d</bold>). <italic>β</italic> = 0.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>e</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 1.3 (solid), 1.6 (dot), and 1.9 (dash). (<bold>f</bold>). <italic>β</italic> = 1.5, <italic>α</italic> = 2.3 (solid), 2.6 (dot), and 2.9 (dash). (<bold>g</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>). (<bold>h</bold>). <italic>x</italic><sub>3</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>β</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 1.7).</p>
Full article ">Figure 30
<p>Plots of <italic>c</italic><sub>eq4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>c</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>c</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>c</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>c</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>c</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.2 (solid), 2.8 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>c</italic><sub>eq4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 31
<p>Plots of <italic>k</italic><sub>eq4</sub> for <italic>k</italic> = 1. (<bold>a</bold>). <italic>k</italic><sub>eq4</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.3 (solid), 0.6 (dot), 0.9 (dash). (<bold>b</bold>). <italic>k</italic><sub>eq4</sub> when <italic>λ</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>k</italic><sub>eq4</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 32
<p>Plots of <italic>ζ</italic><sub>eq4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ζ</italic><sub>eq4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 32 Cont.
<p>Plots of <italic>ζ</italic><sub>eq4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ζ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ζ</italic><sub>eq4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 33
<p>Plots of <italic>ω</italic><sub>eqn4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ω</italic><sub>eqn4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 33 Cont.
<p>Plots of <italic>ω</italic><sub>eqn4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.8 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ω</italic><sub>eqn4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ω</italic><sub>eqn4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 34
<p>Plots of <italic>ω</italic><sub>eqd4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 1.7 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 2.5 (solid), 2.7 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ω</italic><sub>eqd4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 34 Cont.
<p>Plots of <italic>ω</italic><sub>eqd4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 1.7 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 2.5 (solid), 2.7 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>ω</italic><sub>eqd4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>ω</italic><sub>eqd4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 35
<p>Plots of <italic>γ</italic><sub>eq4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 1.7 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 2.5 (solid), 2.7 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>γ</italic><sub>eq4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 35 Cont.
<p>Plots of <italic>γ</italic><sub>eq4</sub> when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 1.7 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.8 when <italic>α</italic>(<italic>ω</italic>) = 2.5 (solid), 2.7 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>γ</italic><sub>eq4</sub> for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>γ</italic><sub>eq4</sub> when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 36
<p>Plots of |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| when <italic>m</italic> = 1, <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). |<italic>H</italic><sub>4</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 37
<p>Plots of <italic>φ</italic><sub>4</sub>(<italic>ω</italic>). (<bold>a</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 37 Cont.
<p>Plots of <italic>φ</italic><sub>4</sub>(<italic>ω</italic>). (<bold>a</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot). (<bold>e</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>f</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 and <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7). (<bold>g</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.5 (solid), 2.5 (dot), when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9). (<bold>h</bold>). <italic>φ</italic><sub>4</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.3, 2.7) and <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 38
<p>Plots of <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5. (<bold>e</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 2.5. (<bold>f</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 38 Cont.
<p>Plots of <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5. (<bold>e</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 2.5. (<bold>f</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 38 Cont.
<p>Plots of <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) when <italic>ω</italic> = 2 and <italic>λ</italic>(<italic>ω</italic>) = 0.5 when <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5. (<bold>d</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 1.5. (<bold>e</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>) and <italic>α</italic>(<italic>ω</italic>) = 2.5. (<bold>f</bold>). <italic>x</italic><sub>4</sub>(<italic>t</italic>) for <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 39
<p>Plots of <italic>c</italic><sub>eq5</sub> when <italic>k</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 (solid), 0.6 (dot), 0.3 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>c</italic><sub>eq5</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 40
<p>Plots of <italic>ζ</italic><sub>eq5</sub> when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 (solid), 0.6 (dot), 0.3 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>ζ</italic><sub>eq5</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 41
<p>Plots of <italic>ω</italic><sub>eqn5</sub> when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 (solid), 0.6 (dot), 0.3 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>ω</italic><sub>eqn5</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 42
<p>Plots of <italic>ω</italic><sub>eqd5</sub> when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 (solid), 0.6 (dot), 0.3 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>ω</italic><sub>eqd5</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 43
<p>Plots of <italic>γ</italic><sub>eq5</sub> when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.9 (solid), 0.6 (dot), 0.3 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq5</sub> for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>γ</italic><sub>eq5</sub> when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 44
<p>Plots of |<italic>H</italic><sub>5</sub>(<italic>ω</italic>)| when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>5</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.09 (solid), 0.06 (dot), 0.03 (dash). (<bold>b</bold>). |<italic>H</italic><sub>5</sub>(<italic>ω</italic>)| for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). |<italic>H</italic><sub>5</sub>(<italic>ω</italic>)| when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 45
<p>Plots of <italic>φ</italic><sub>5</sub>(<italic>ω</italic>) when <italic>m</italic> = 1 and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>5</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.09 (solid), 0.06 (dot), 0.03 (dash). (<bold>b</bold>). <italic>φ</italic><sub>5</sub>(<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>φ</italic><sub>5</sub>(<italic>ω</italic>) when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 46
<p>Plots of <italic>x</italic><sub>5</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) for <italic>λ</italic> = 0.9 (solid), <italic>λ</italic> = 0.6 (dot), <italic>λ</italic> = 0.3 (dash). (<bold>b</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 46 Cont.
<p>Plots of <italic>x</italic><sub>5</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) for <italic>λ</italic> = 0.9 (solid), <italic>λ</italic> = 0.6 (dot), <italic>λ</italic> = 0.3 (dash). (<bold>b</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.5 + 0.4cos(2<italic>ω</italic>). (<bold>c</bold>). <italic>x</italic><sub>5</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) is a uniformly distributed random function with the range (0.1, 0.9).</p>
Full article ">Figure 47
<p>Plots of <italic>c</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash) (negative damping). (<bold>c</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash) (negative damping). (<bold>e</bold>). <italic>c</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>c</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>c</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>c</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 47 Cont.
<p>Plots of <italic>c</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash) (negative damping). (<bold>c</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>c</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash) (negative damping). (<bold>e</bold>). <italic>c</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>c</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>c</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>c</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 48
<p>Plots of <italic>ζ</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 48 Cont.
<p>Plots of <italic>ζ</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ζ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>ζ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 49
<p>Plots of <italic>ω</italic><sub>eqn6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 49 Cont.
<p>Plots of <italic>ω</italic><sub>eqn6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqn6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 50
<p>Plots of <italic>ω</italic><sub>eqd6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.9 and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>ω</italic><sub>eqd6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.9 and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>ω</italic><sub>eqd6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>ω</italic><sub>eqd6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>ω</italic><sub>eqd6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>ω</italic><sub>eqd6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>ω</italic><sub>eqd6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>ω</italic><sub>eqd6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 51
<p>Plots of <italic>γ</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.3 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.3 and <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 51 Cont.
<p>Plots of <italic>γ</italic><sub>eq6</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>γ</italic><sub>eq6</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.3 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.3 and <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.7 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>γ</italic><sub>eq6</sub> when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 52
<p>Plots of |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 52 Cont.
<p>Plots of |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). |<italic>H</italic><sub>6</sub>(<italic>ω</italic>)| when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 53
<p>Plots of <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 53 Cont.
<p>Plots of <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>b</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 0.7 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>c</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 1.6 (dot), 1.9 (dash). (<bold>d</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>φ</italic><sub>6</sub>(<italic>ω</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 54
<p>Plots of <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic> = 1.8, <italic>β</italic> = 1.2, for <italic>λ</italic> = 0.8 (solid), <italic>λ</italic> = 0.5 (dot), <italic>λ</italic> = 0.2 (dash). (<bold>b</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>α</italic> = 1.8, <italic>λ</italic> = 0.8 for <italic>β</italic> = 1.2 (solid), 0.8 (dot), 0.4 (dash). (<bold>c</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>β</italic> = 0.8, <italic>λ</italic> = 0.8 for <italic>α</italic> = 2.2 (solid), <italic>α</italic> = 1.8 (dot), <italic>α</italic> = 1.4 (dash). (<bold>d</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 54 Cont.
<p>Plots of <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic> = 1.8, <italic>β</italic> = 1.2, for <italic>λ</italic> = 0.8 (solid), <italic>λ</italic> = 0.5 (dot), <italic>λ</italic> = 0.2 (dash). (<bold>b</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>α</italic> = 1.8, <italic>λ</italic> = 0.8 for <italic>β</italic> = 1.2 (solid), 0.8 (dot), 0.4 (dash). (<bold>c</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>β</italic> = 0.8, <italic>λ</italic> = 0.8 for <italic>α</italic> = 2.2 (solid), <italic>α</italic> = 1.8 (dot), <italic>α</italic> = 1.4 (dash). (<bold>d</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 54 Cont.
<p>Plots of <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic> = 1.8, <italic>β</italic> = 1.2, for <italic>λ</italic> = 0.8 (solid), <italic>λ</italic> = 0.5 (dot), <italic>λ</italic> = 0.2 (dash). (<bold>b</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>α</italic> = 1.8, <italic>λ</italic> = 0.8 for <italic>β</italic> = 1.2 (solid), 0.8 (dot), 0.4 (dash). (<bold>c</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) for <italic>β</italic> = 0.8, <italic>λ</italic> = 0.8 for <italic>α</italic> = 2.2 (solid), <italic>α</italic> = 1.8 (dot), <italic>α</italic> = 1.4 (dash). (<bold>d</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.3 and <italic>λ</italic>(<italic>ω</italic>) = 0.2 for <italic>α</italic>(<italic>ω</italic>) = 2.3 (solid), 2.6 (dot), 2.9 (dash). (<bold>e</bold>). when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>β</italic>(<italic>ω</italic>) = 0.7 (solid) and <italic>β</italic>(<italic>ω</italic>) = 1.3 (dot). (<bold>f</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>g</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) and <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot). (<bold>h</bold>). <italic>x</italic><sub>6</sub>(<italic>t</italic>) when <italic>α</italic>(<italic>ω</italic>) = 1.4 + cos(2<italic>ω</italic>), <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>), and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 55
<p>Plots of <italic>c</italic><sub>eq7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>c</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.9 (dot), 1.6 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>c</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 0.3 (solid), 0.9 (dot), 1.6 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.9. (<bold>c</bold>). <italic>c</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash). (<bold>d</bold>). <italic>c</italic><sub>eq7</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) 1.6 (solid), 0.9 (dot), 0.3 (dash).</p>
Full article ">Figure 56
<p>Plots of <italic>ζ</italic><sub>eq7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>ζ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dot). (<bold>e</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 56 Cont.
<p>Plots of <italic>ζ</italic><sub>eq7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ζ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>ζ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dot). (<bold>e</bold>). <italic>ζ</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 57
<p>Plots of <italic>ω</italic><sub>eqn7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqn7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>ω</italic><sub>eqn7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>ω</italic><sub>eqn6</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.8 (solid), 0.2 (dot). (<bold>e</bold>). <italic>ω</italic><sub>eqn7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 58
<p>Plots of <italic>ω</italic><sub>eqd7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>ω</italic><sub>eqd7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>ω</italic><sub>eqd7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>ω</italic><sub>eqd7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>ω</italic><sub>eqd7</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.8 (dot).</p>
Full article ">Figure 59
<p>Plots of <italic>γ</italic><sub>eq7</sub> for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>γ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.3 (dot) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>γ</italic><sub>eq7</sub> with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.3 (dot) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>γ</italic><sub>eq7</sub> when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>γ</italic><sub>eq7</sub> when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.9 (solid), 0.1 (dot).</p>
Full article ">Figure 60
<p>Plots of |<italic>H</italic><sub>7</sub>(<italic>ω</italic>)| for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). |<italic>H</italic><sub>7</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). |<italic>H</italic><sub>7</sub>(<italic>ω</italic>)| with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). |<italic>H</italic><sub>7</sub>(<italic>ω</italic>)| when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). |<italic>H</italic><sub>7</sub>(<italic>ω</italic>)| when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.3 (dot).</p>
Full article ">Figure 61
<p>Plots of <italic>φ</italic><sub>7</sub>(<italic>ω</italic>) for <italic>m</italic> = 1, <italic>c</italic> = 0.2, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>φ</italic><sub>7</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>φ</italic><sub>7</sub>(<italic>ω</italic>) with <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>φ</italic><sub>7</sub>(<italic>ω</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>d</bold>). <italic>φ</italic><sub>7</sub>(<italic>ω</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 0.1 for <italic>α</italic>(<italic>ω</italic>) = 1.3 (solid), 2.3 (dot).</p>
Full article ">Figure 62
<p>Plots of <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>d</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.9, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>e</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.3, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>f</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>g</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.5 (solid), 0.5 (dot). (<bold>h</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 62 Cont.
<p>Plots of <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>d</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.9, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>e</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.3, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>f</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>g</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.5 (solid), 0.5 (dot). (<bold>h</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
Full article ">Figure 62 Cont.
<p>Plots of <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>ω</italic> = 2, <italic>F</italic><sub>0</sub> = 1, <italic>θ</italic> = 0, <italic>m</italic> = 1, <italic>c</italic> = 1, and <italic>k</italic> = 1. (<bold>a</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.7. (<bold>b</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.6 (solid), 0.9 (dot), 0.3 (dash) for <italic>λ</italic>(<italic>ω</italic>) = 0.2. (<bold>c</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.6, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>d</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.9, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>e</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 0.3, <italic>λ</italic>(<italic>ω</italic>) = 0.8 (solid), 0.5 (dot), 0.1 (dash). (<bold>f</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) for <italic>λ</italic>(<italic>ω</italic>) = 0.7 (solid), 0.2 (dot). (<bold>g</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>) for <italic>β</italic>(<italic>ω</italic>) = 1.5 (solid), 0.5 (dot). (<bold>h</bold>). <italic>x</italic><sub>7</sub>(<italic>t</italic>) when <italic>β</italic>(<italic>ω</italic>) = 1.2 + 0.5cos(2<italic>ω</italic>) and <italic>λ</italic>(<italic>ω</italic>) = 0.1 + 0.4cos(2<italic>ω</italic>).</p>
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13 pages, 1115 KiB  
Article
Practical Stability of Observer-Based Control for Nonlinear Caputo–Hadamard Fractional-Order Systems
by Rihab Issaoui, Omar Naifar, Mehdi Tlija, Lassaad Mchiri and Abdellatif Ben Makhlouf
Fractal Fract. 2024, 8(9), 531; https://doi.org/10.3390/fractalfract8090531 - 11 Sep 2024
Viewed by 155
Abstract
This paper investigates the problem of observer-based control for a class of nonlinear systems described by the Caputo–Hadamard fractional-order derivative. Given the growing interest in fractional-order systems for their ability to capture complex dynamics, ensuring their practical stability remains a significant challenge. We [...] Read more.
This paper investigates the problem of observer-based control for a class of nonlinear systems described by the Caputo–Hadamard fractional-order derivative. Given the growing interest in fractional-order systems for their ability to capture complex dynamics, ensuring their practical stability remains a significant challenge. We propose a novel concept of practical stability tailored to nonlinear Hadamard fractional-order systems, which guarantees that the system solutions converge to a small ball containing the origin, thereby enhancing their robustness against perturbations. Furthermore, we introduce a practical observer design that extends the classical observer framework to fractional-order systems under an enhanced One-Sided Lipschitz (OSL) condition. This extended OSL condition ensures the convergence of the proposed practical observer, even in the presence of significant nonlinearities and disturbances. Notably, the novelty of our approach lies in the extension of both the practical observer and the stability criteria, which are innovative even in the integer-order case. Theoretical results are substantiated through numerical examples, demonstrating the feasibility of the proposed method in real-world control applications. Our contributions pave the way for the development of robust observers in fractional-order systems, with potential applications across various engineering domains. Full article
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Figure 1

Figure 1
<p>The actual state <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>x</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math> and its corresponding estimate for Example 1.</p>
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<p>The actual state <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>x</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> </mrow> </semantics></math> and its corresponding estimate for Example 1.</p>
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<p>Actual states <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>x</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mo> </mo> <msub> <mrow> <mi>x</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msub> </mrow> </semantics></math> and their estimates for Example 2.</p>
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40 pages, 3816 KiB  
Article
Multiscale Analysis of Sandwich Beams with Polyurethane Foam Core: A Comparative Study of Finite Element Methods and Radial Point Interpolation Method
by Jorge Belinha
Materials 2024, 17(18), 4466; https://doi.org/10.3390/ma17184466 - 11 Sep 2024
Viewed by 313
Abstract
This study presents a comprehensive multiscale analysis of sandwich beams with a polyurethane foam (PUF) core, delivering a numerical comparison between finite element methods (FEMs) and a meshless method: the radial point interpolation method (RPIM). This work aims to combine RPIM with homogenisation [...] Read more.
This study presents a comprehensive multiscale analysis of sandwich beams with a polyurethane foam (PUF) core, delivering a numerical comparison between finite element methods (FEMs) and a meshless method: the radial point interpolation method (RPIM). This work aims to combine RPIM with homogenisation techniques for multiscale analysis, being divided in two phases. In the first phase, bulk PUF material was modified by incorporating circular holes to create PUFs with varying volume fractions. Then, using a homogenisation technique coupled with FEM and four versions of RPIM, the homogenised mechanical properties of distinct PUF with different volume fractions were determined. It was observed that RPIM formulations, with higher-order integration schemes, are capable of approximating the solution and field smoothness of high-order FEM formulations. However, seeking a comparable field smoothness represents prohibitive computational costs for RPIM formulations. In a second phase, the obtained homogenised mechanical properties were applied to large-scale sandwich beam problems with homogeneous and approximately functionally graded cores, showing RPIM’s capability to closely approximate FEM results. The analysis of stress distributions along the thickness of the beam highlighted RPIM’s tendency to yield lower stress values near domain edges, albeit with convergence towards agreement among different formulations. It was found that RPIM formulations with lower nodal connectivity are very efficient, balancing computational cost and accuracy. Overall, this study shows RPIM’s viability as an alternative to FEM for addressing practical elasticity applications. Full article
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Figure 1

Figure 1
<p>Parametric representation of the analysed RVE.</p>
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<p>Discretisation meshes used with the FEM and RPIM analyses. (<b>a</b>) A total of 138 nodes and 234 triangular elements. (<b>b</b>) A total of483 nodes and 884 triangular elements. (<b>c</b>) A total of 1785 nodes and 3408 triangular elements. (<b>d</b>) A total of 4005 nodes and 7768 triangular elements. (<b>e</b>) A total of 6993 nodes and 13,664 triangular elements.</p>
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<p>Discretisation convergence study of the following elastic mechanical properties: (<b>a</b>) <math display="inline"><semantics> <msub> <mi>E</mi> <mi>x</mi> </msub> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <msub> <mi>E</mi> <mi>z</mi> </msub> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <msub> <mi>G</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math>, and (<b>d</b>) <math display="inline"><semantics> <msub> <mi>ν</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math>.</p>
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<p>von Mises equivalent stress distribution for the following formulations: FEM-6n (<b>a</b>–<b>c</b>), FEM-3n (<b>d</b>–<b>f</b>), and CRPIM (<b>g</b>–<b>i</b>). The results corresponding to <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>100</mn> </msub> </semantics></math> are shown in (<b>a</b>,<b>d</b>,<b>g</b>), <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>010</mn> </msub> </semantics></math> results are shown in (<b>b</b>,<b>e</b>,<b>h</b>), and <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>001</mn> </msub> </semantics></math> results are shown in (<b>c</b>,<b>f</b>,<b>i</b>).</p>
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<p>von Mises equivalent stress distribution for the following formulations: MRPIM16 (<b>a</b>–<b>c</b>), MRPIM9 (<b>d</b>–<b>f</b>), and MRPIM4 (<b>g</b>–<b>i</b>). The results corresponding to <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>100</mn> </msub> </semantics></math> are shown in (<b>a</b>,<b>d</b>,<b>g</b>), <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>010</mn> </msub> </semantics></math> results are shown in (<b>b</b>,<b>e</b>,<b>h</b>), and <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>001</mn> </msub> </semantics></math> results are shown in (<b>c</b>,<b>f</b>,<b>i</b>).</p>
Full article ">Figure 6
<p>von Mises equivalent stress distribution obtained with CRPIM considering a higher-order integration scheme: (<b>a</b>) <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>100</mn> </msub> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>010</mn> </msub> </semantics></math>, and (<b>c</b>) <math display="inline"><semantics> <msub> <mover accent="true"> <mi mathvariant="bold">f</mi> <mo stretchy="false">˜</mo> </mover> <mn>001</mn> </msub> </semantics></math>.</p>
Full article ">Figure 7
<p>Overall computational cost of FEM and RPIM formulations.</p>
Full article ">Figure 8
<p>Discretisation meshes used with the FEM and RPIM analyses. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.95</mn> </mrow> </semantics></math>; 5073 nodes and 9839 triangular elements. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.90</mn> </mrow> </semantics></math>; 4807 nodes and 9321 triangular elements. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.85</mn> </mrow> </semantics></math>; 4539 nodes and 8803 triangular elements. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.80</mn> </mrow> </semantics></math>; 4273 nodes and 8285 triangular elements. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.75</mn> </mrow> </semantics></math>; 4005 nodes and 7767 triangular elements. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.70</mn> </mrow> </semantics></math>; 3739 nodes and 7249 triangular elements. (<b>g</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.65</mn> </mrow> </semantics></math>; 3472 nodes and 6732 triangular elements. (<b>h</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.60</mn> </mrow> </semantics></math>; 3205 nodes and 6214 triangular elements. (<b>i</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.55</mn> </mrow> </semantics></math>; 2937 nodes and 5696 triangular elements. (<b>j</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.50</mn> </mrow> </semantics></math>; 2671 nodes and 5178 triangular elements.</p>
Full article ">Figure 9
<p>Influence of the volume fraction <math display="inline"><semantics> <msub> <mi>v</mi> <mi>f</mi> </msub> </semantics></math> on the homogenised elastic mechanical properties: (<b>a</b>) <math display="inline"><semantics> <msub> <mi>E</mi> <mi>x</mi> </msub> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <msub> <mi>E</mi> <mi>y</mi> </msub> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <msub> <mi>G</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math>, and (<b>d</b>) <math display="inline"><semantics> <msub> <mi>ν</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math>.</p>
Full article ">Figure 10
<p>Sandwich cantilever beam with aluminium face sheets and PUF core. Three material domains were assumed: aluminium top-face sheet (3), PUF-core (2), and aluminium bottom face sheet (1).</p>
Full article ">Figure 11
<p>Variation in the normal stress <math display="inline"><semantics> <msub> <mi>σ</mi> <mrow> <mi>x</mi> <mi>x</mi> </mrow> </msub> </semantics></math> along the aluminium top face sheet for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 12
<p>Variation in the normal stress <math display="inline"><semantics> <msub> <mi>σ</mi> <mrow> <mi>x</mi> <mi>x</mi> </mrow> </msub> </semantics></math> along the PUF core for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 13
<p>Variation in the normal stress <math display="inline"><semantics> <msub> <mi>σ</mi> <mrow> <mi>x</mi> <mi>x</mi> </mrow> </msub> </semantics></math> along the aluminium bottom face sheet for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 14
<p>Variation in the shear stress <math display="inline"><semantics> <msub> <mi>τ</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math> along the aluminium top face sheet for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 15
<p>Variation in the shear stress <math display="inline"><semantics> <msub> <mi>τ</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math> along the PUF core for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 16
<p>Variation in the shear stress <math display="inline"><semantics> <msub> <mi>τ</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math> along the aluminium bottom face sheet for distinct PUF cores. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>. (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.6</mn> </mrow> </semantics></math>. (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.7</mn> </mrow> </semantics></math>. (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.8</mn> </mrow> </semantics></math>. (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>0.9</mn> </mrow> </semantics></math>. (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>v</mi> <mi>f</mi> </msub> <mo>=</mo> <mn>1.0</mn> </mrow> </semantics></math>.</p>
Full article ">Figure 17
<p>Sandwich cantilever beam with aluminium face sheets and a functionally graded PUF core. Ten material domains were assumed: aluminium top-face sheet (10), PUF-cores with potential distinct densities (2–9), and aluminium bottom face sheet (1).</p>
Full article ">Figure 18
<p>Variation in the normal stress <math display="inline"><semantics> <msub> <mi>σ</mi> <mrow> <mi>x</mi> <mi>x</mi> </mrow> </msub> </semantics></math> along the beam thickness. (<b>a</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.9</mn> <mo>,</mo> <mn>1.0</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>b</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.9</mn> <mo>,</mo> <mn>1.0</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>c</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.1</mn> <mo>,</mo> <mn>0.9</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>d</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.1</mn> <mo>,</mo> <mn>0.9</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>e</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.0</mn> <mo>,</mo> <mn>0.1</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>f</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.0</mn> <mo>,</mo> <mn>0.1</mn> <mo>]</mo> </mrow> </semantics></math> m.</p>
Full article ">Figure 19
<p>Variatio n in the shear stress <math display="inline"><semantics> <msub> <mi>τ</mi> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> </semantics></math> along the beam thickness. (<b>a</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.9</mn> <mo>,</mo> <mn>1.0</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>b</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.9</mn> <mo>,</mo> <mn>1.0</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>c</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.1</mn> <mo>,</mo> <mn>0.9</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>d</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.1</mn> <mo>,</mo> <mn>0.9</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>e</b>) FG1 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.0</mn> <mo>,</mo> <mn>0.1</mn> <mo>]</mo> </mrow> </semantics></math> m. (<b>f</b>) FG2 beam for <math display="inline"><semantics> <mrow> <mi>y</mi> <mo>∈</mo> <mo>[</mo> <mn>0.0</mn> <mo>,</mo> <mn>0.1</mn> <mo>]</mo> </mrow> </semantics></math> m.</p>
Full article ">Figure A1
<p>Integration scheme for the RPIM using a rectangular domain and a regular background integration grid.</p>
Full article ">
14 pages, 4664 KiB  
Article
Exploring Soliton Solutions for Fractional Nonlinear Evolution Equations: A Focus on Regularized Long Wave and Shallow Water Wave Models with Beta Derivative
by Sujoy Devnath, Maha M. Helmi and M. Ali Akbar
Computation 2024, 12(9), 187; https://doi.org/10.3390/computation12090187 - 11 Sep 2024
Viewed by 291
Abstract
The fractional regularized long wave equation and the fractional nonlinear shallow-water wave equation are the noteworthy models in the domains of fluid dynamics, ocean engineering, plasma physics, and microtubules in living cells. In this study, a reliable and efficient improved F-expansion technique, along [...] Read more.
The fractional regularized long wave equation and the fractional nonlinear shallow-water wave equation are the noteworthy models in the domains of fluid dynamics, ocean engineering, plasma physics, and microtubules in living cells. In this study, a reliable and efficient improved F-expansion technique, along with the fractional beta derivative, has been utilized to explore novel soliton solutions to the stated wave equations. Consequently, the study establishes a variety of reliable and novel soliton solutions involving trigonometric, hyperbolic, rational, and algebraic functions. By setting appropriate values for the parameters, we obtained peakons, anti-peakon, kink, bell, anti-bell, singular periodic, and flat kink solitons. The physical behavior of these solitons is demonstrated in detail through three-dimensional, two-dimensional, and contour representations. The impact of the fractional-order derivative on the wave profile is notable and is illustrated through two-dimensional graphs. It can be stated that the newly established solutions might be further useful for the aforementioned domains. Full article
(This article belongs to the Section Computational Engineering)
Show Figures

Figure 1

Figure 1
<p>Graphical exhibition of the bell-shaped soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>V</mi> </mrow> <mrow> <mn>3</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 2
<p>Graphical exhibition of the compacton soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>V</mi> </mrow> <mrow> <mn>5</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 3
<p>Graphical exhibition of the anti-compacton soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>V</mi> </mrow> <mrow> <mn>5</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 4
<p>Graphical exhibition of the singular periodic soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>V</mi> </mrow> <mrow> <mn>21</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 5
<p>Graphical exhibition of the kink soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>R</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 6
<p>Graphical exhibition of the general soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>R</mi> </mrow> <mrow> <mn>3</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">Figure 7
<p>Graphical exhibition of the singular periodic soliton of the solution <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>R</mi> </mrow> <mrow> <mn>7</mn> </mrow> </msub> <mfenced separators="|"> <mrow> <mi>x</mi> <mo>,</mo> <mi>t</mi> </mrow> </mfenced> </mrow> </semantics></math>. (<b>a</b>) 3D figure. (<b>b</b>) 2D figure. (<b>c</b>) Contour plot.</p>
Full article ">
21 pages, 688 KiB  
Article
Research on New Interval-Valued Fractional Integrals with Exponential Kernel and Their Applications
by Abdulrahman F. Aljohani, Ali Althobaiti and Saad Althobaiti
Axioms 2024, 13(9), 616; https://doi.org/10.3390/axioms13090616 - 11 Sep 2024
Viewed by 218
Abstract
This paper aims to introduce a new fractional extension of the interval Hermite–Hadamard (ℋℋ), ℋℋ–Fejér, and Pachpatte-type inequalities for left- and right-interval-valued harmonically convex mappings (ℒRIVH convex mappings) with an exponential function in the kernel. We use fractional operators to develop several [...] Read more.
This paper aims to introduce a new fractional extension of the interval Hermite–Hadamard (ℋℋ), ℋℋ–Fejér, and Pachpatte-type inequalities for left- and right-interval-valued harmonically convex mappings (ℒRIVH convex mappings) with an exponential function in the kernel. We use fractional operators to develop several generalizations, capturing unique outcomes that are currently under investigation, while also introducing a new operator. Generally, we propose two methods that, in conjunction with more generalized fractional integral operators with an exponential function in the kernel, can address certain novel generalizations of increasing mappings under the assumption of ℒRIV convexity, yielding some noteworthy results. The results produced by applying the suggested scheme show that the computational effects are extremely accurate, flexible, efficient, and simple to implement in order to explore the path of upcoming intricate waveform and circuit theory research. Full article
(This article belongs to the Special Issue Theory and Application of Integral Inequalities)
16 pages, 5306 KiB  
Article
Investigation of Sewage Sludge–Derived Biochar for Enhanced Pollutant Adsorption: Effect of Particle Size and Alkali Treatment
by Andy Kofi Agoe, Stavros G. Poulopoulos, Yerbol Sarbassov and Dhawal Shah
Energies 2024, 17(18), 4554; https://doi.org/10.3390/en17184554 - 11 Sep 2024
Viewed by 350
Abstract
Sewage sludge (SS) holds promise for environmental, agricultural, and energy applications. However, its direct use is limited due to contaminant concerns. Pyrolysis can turn SS into beneficial products like bio-oil and biochar. This study explores biochar production from SS pyrolysis and its potential [...] Read more.
Sewage sludge (SS) holds promise for environmental, agricultural, and energy applications. However, its direct use is limited due to contaminant concerns. Pyrolysis can turn SS into beneficial products like bio-oil and biochar. This study explores biochar production from SS pyrolysis and its potential for pollutant adsorption. The effects of pyrolysis temperature (500, 650, 850 °C) and SS particle size (800–1000 µm, 400–800 µm, 100–400 µm, ≤100 µm) on biochar yield and adsorption capacity for methylene blue and mercury were investigated. Regardless of particle size and temperature, SS-derived biochar exhibited second-order adsorption kinetics. Biochar with a particle size of 100–400 µm displayed the highest potential for methylene blue adsorption. Subsequent alkali treatment (biochar:NaOH = 3:4) of these particles significantly increased specific surface area from 27.5 m2/g to 144.27 m2/g and further enhanced adsorption capacities for both methylene blue (from 9 mg/g to 35 mg/g) and mercury (from 17 mg/g to 36 mg/g). These findings suggest that SS-derived biochar, particularly the 100–400 µm fraction with alkali treatment, presents a promising cost-effective adsorbent for water treatment, aligning with circular economy principles. Full article
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<p>Schematic diagram of a horizontal quartz tube reactor used for pyrolysis of SS.</p>
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<p>Schematic diagram of mercury thermal decomposition experimental system.</p>
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<p>Effect of different SS particle sizes on the biochar yield (%) at different pyrolysis temperatures. Standard deviations were all less than ±0.5%.</p>
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<p>Total amount of Fe (<b>A</b>), Zn (<b>B</b>), and Mn (<b>C</b>) in the different particle sizes of sewage sludge at 500, 650, and 800 °C.</p>
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<p>Scanning electron microscope of sludge-derived biochar (S<sub>3</sub> ; <b>A</b>–<b>C</b>) and modified biochar (MS<sub>3</sub> ; <b>D</b>–<b>F</b>) at 500 °C, 650 °C, and 800 °C.</p>
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<p>Structural characterization of sewage sludge, (<b>A</b>) sludge-derived biochar (S<sub>3</sub>), and (<b>B</b>) modified sludge–derived biochar (MS<sub>3</sub>) for S<sub>3</sub>-sized particles at 500, 650, and 800 °C.</p>
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<p>Adsorption of MB over different-sized SS-derived biochar particles produced at 500 °C, pH: 6.5, 30 mg dose. (<b>A</b>) Adsorption kinetics of 10 mg/L of MB along with fit using Pseudo-second-order kinetics model. (<b>B</b>) Effect of initial MB concentration from 10 to 50 mg/L over equilibrium adsorption capacity.</p>
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<p>Equilibrium adsorption capacity with adsorbent dose of S<sub>3</sub>: 100–400 µm in 10 mg/L of MB, pH: 6.5.</p>
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<p>Adsorption capacity of methylene blue (<b>A</b>) and mercury (<b>B</b>) with time (C<sub>o</sub> (MB): 400 mg/L of MB, pH: 6.5, 500 mg mass dose).</p>
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22 pages, 1727 KiB  
Article
An 8D Hyperchaotic System of Fractional-Order Systems Using the Memory Effect of Grünwald–Letnikov Derivatives
by Muhammad Sarfraz, Jiang Zhou and Fateh Ali
Fractal Fract. 2024, 8(9), 530; https://doi.org/10.3390/fractalfract8090530 - 11 Sep 2024
Viewed by 235
Abstract
We utilize Lyapunov exponents to quantitatively assess the hyperchaos and categorize the limit sets of complex dynamical systems. While there are numerous methods for computing Lyapunov exponents in integer-order systems, these methods are not suitable for fractional-order systems because of the nonlocal characteristics [...] Read more.
We utilize Lyapunov exponents to quantitatively assess the hyperchaos and categorize the limit sets of complex dynamical systems. While there are numerous methods for computing Lyapunov exponents in integer-order systems, these methods are not suitable for fractional-order systems because of the nonlocal characteristics of fractional-order derivatives. This paper introduces innovative eight-dimensional chaotic systems that investigate fractional-order dynamics. These systems exploit the memory effect inherent in the Grünwald–Letnikov (G-L) derivative. This approach enhances the system’s applicability and compatibility with traditional integer-order systems. An 8D Chen’s fractional-order system is utilized to showcase the effectiveness of the presented methodology for hyperchaotic systems. The simulation results demonstrate that the proposed algorithm outperforms existing algorithms in both accuracy and precision. Moreover, the study utilizes the 0–1 Test for Chaos, Kolmogorov–Sinai (KS) entropy, the Kaplan–Yorke dimension, and the Perron Effect to analyze the proposed eight-dimensional fractional-order system. These additional metrics offer a thorough insight into the system’s chaotic behavior and stability characteristics. Full article
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<p>LEs of the 8D hyperchaotic system for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>100</mn> </mrow> </semantics></math>.</p>
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<p>Time histories of <math display="inline"><semantics> <mrow> <mo>(</mo> <mi mathvariant="bold">a</mi> <mo>)</mo> <mo> </mo> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>,</mo> <mo>(</mo> <mi mathvariant="bold">b</mi> <mo>)</mo> <mo> </mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>,</mo> <mo>(</mo> <mi mathvariant="bold">c</mi> <mo>)</mo> <mo> </mo> <msub> <mi>x</mi> <mn>3</mn> </msub> <mo>,</mo> <mo>(</mo> <mi mathvariant="bold">d</mi> <mo>)</mo> <mo> </mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math> for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>100</mn> </mrow> </semantics></math>.</p>
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<p>The 2D phase portraits for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>100</mn> </mrow> </semantics></math>: (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math>.</p>
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<p>The 3D phase portraits for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>100</mn> </mrow> </semantics></math>: (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>4</mn> </msub> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>5</mn> </msub> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>6</mn> </msub> </mrow> </semantics></math>, (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math>, (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>8</mn> </msub> </mrow> </semantics></math>.</p>
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<p>LEs of the 8D hyperchaotic system for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>200</mn> </mrow> </semantics></math>.</p>
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<p>Time histories of <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>,</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>,</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> <mo>,</mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math> for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>200</mn> </mrow> </semantics></math>.</p>
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<p>The 2D phase portraits for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>200</mn> </mrow> </semantics></math>: (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math>.</p>
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<p>The 3D phase portraits for set of fractional-orders FO<sub>3</sub> at <math display="inline"><semantics> <mrow> <mi>t</mi> <mo>=</mo> <mn>200</mn> </mrow> </semantics></math>: (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>3</mn> </msub> </mrow> </semantics></math>, (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>4</mn> </msub> </mrow> </semantics></math>, (<b>c</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>5</mn> </msub> </mrow> </semantics></math>, (<b>d</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>6</mn> </msub> </mrow> </semantics></math>, (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>7</mn> </msub> </mrow> </semantics></math>, (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mi>x</mi> <mn>1</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>2</mn> </msub> <mo>−</mo> <msub> <mi>x</mi> <mn>8</mn> </msub> </mrow> </semantics></math>.</p>
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<p>The 0–1 Test for Chaos: numerical time series of (<b>left</b>) mean square displacement <math display="inline"><semantics> <mrow> <mo stretchy="false">[</mo> <msub> <mi>M</mi> <mi>i</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mi>n</mi> <mo stretchy="false">)</mo> </mrow> <mo stretchy="false">]</mo> </mrow> </semantics></math>, (<b>right</b>) dynamics of translation components <math display="inline"><semantics> <mrow> <mo stretchy="false">[</mo> <msub> <mi>p</mi> <mi>i</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mi>t</mi> <mo stretchy="false">)</mo> </mrow> <mo>,</mo> <msub> <mi>q</mi> <mi>i</mi> </msub> <mrow> <mo stretchy="false">(</mo> <mi>t</mi> <mo stretchy="false">)</mo> </mrow> <mo stretchy="false">]</mo> </mrow> </semantics></math> for <math display="inline"><semantics> <msub> <mi>x</mi> <mn>1</mn> </msub> </semantics></math>, <math display="inline"><semantics> <msub> <mi>x</mi> <mn>2</mn> </msub> </semantics></math>, <math display="inline"><semantics> <msub> <mi>x</mi> <mn>6</mn> </msub> </semantics></math>, and <math display="inline"><semantics> <msub> <mi>x</mi> <mn>7</mn> </msub> </semantics></math>.</p>
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12 pages, 315 KiB  
Article
Fractional Calculus for Non-Discrete Signed Measures
by Vassili N. Kolokoltsov and Elina L. Shishkina
Mathematics 2024, 12(18), 2804; https://doi.org/10.3390/math12182804 - 10 Sep 2024
Viewed by 263
Abstract
In this paper, we suggest a first-ever construction of fractional integral and differential operators based on signed measures including a vector-valued case. The study focuses on constructing the fractional power of the Riemann–Stieltjes integral with a signed measure, using semigroup theory. The main [...] Read more.
In this paper, we suggest a first-ever construction of fractional integral and differential operators based on signed measures including a vector-valued case. The study focuses on constructing the fractional power of the Riemann–Stieltjes integral with a signed measure, using semigroup theory. The main result is a theorem that provides the exact form of a semigroup for the Riemann–Stieltjes integral with a measure having a countable number of extrema. This article provides examples of semigroups based on integral operators with signed measures and discusses the fractional powers of differential operators with partial derivatives. Full article
(This article belongs to the Special Issue Fractional Calculus and Mathematical Applications, 2nd Edition)
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<p><math display="inline"><semantics> <mrow> <msup> <mfenced separators="" open="(" close=")"> <mo>−</mo> <mstyle scriptlevel="0" displaystyle="true"> <mfrac> <mi>d</mi> <mrow> <mi>d</mi> <mi>F</mi> <mo>(</mo> <mi>x</mi> <mo>)</mo> </mrow> </mfrac> </mstyle> </mfenced> <mi>α</mi> </msup> <msup> <mrow> <mo>(</mo> <mi>x</mi> <mo>−</mo> <mn>1</mn> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </semantics></math>.</p>
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