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Search Results (988)

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18 pages, 1754 KiB  
Article
The Characteristics of ARMA (ARIMA) Model and Some Key Points to Be Noted in Application: A Case Study of Changtan Reservoir, Zhejiang Province, China
by Zhuang Liu, Yibin Cui, Chengcheng Ding, Yonghai Gan, Jun Luo, Xiao Luo and Yongguo Wang
Sustainability 2024, 16(18), 7955; https://doi.org/10.3390/su16187955 (registering DOI) - 12 Sep 2024
Abstract
Accurate water quality prediction is the basis for good water environment management and sustainable use of water resources. As an important time series forecasting model, the Autoregressive Moving Average Model (ARMA) plays a crucial role in environmental management and sustainability research. This study [...] Read more.
Accurate water quality prediction is the basis for good water environment management and sustainable use of water resources. As an important time series forecasting model, the Autoregressive Moving Average Model (ARMA) plays a crucial role in environmental management and sustainability research. This study addresses the factors that affect the ARMA model’s forecast accuracy and goodness of fit. The research results show that the sample size used for model parameters estimation is the main influencing factor for the goodness of fit of an ARMA model, and the prediction time is the main factor affecting the prediction error of the model. Constructing a stable and reliable ARMA model requires a certain number of samples for the estimation of model parameters. However, using an excessive number of samples will not further improve the ARMA model’s goodness of fit but rather increase the workload and difficulty of data collection. The ARMA model is not suitable for long-term forecasting because the prediction error of ARMA models increases with the increase of prediction time, and when the prediction time exceeds a certain limit, the fitted values of an ARMA model will almost no longer change with the time, which means the model has lost its significance of prediction. For time series with periodic components, introducing periodic adjustment factors into the ARMA model can reduce the prediction error. These findings enable environmental managers and researchers to apply the ARMA model more rationally, hence developing more precise pollution control and sustainable development plans. Full article
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<p>ACF and PACF graphs of daily time series of water quality indicators in Changtan Reservoir.</p>
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<p>ACF and PACF graphs of monthly time series of water quality indicators in Changtan Reservoir.</p>
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<p>Effect of the length of the past time series used for model parameter estimation on the <math display="inline"><semantics> <mrow> <msup> <mrow> <mover> <mi mathvariant="normal">R</mi> <mo>¯</mo> </mover> </mrow> <mn>2</mn> </msup> </mrow> </semantics></math> of ARMA models.</p>
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<p>The effect of prediction time on the MAPE of ARMA models.</p>
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<p>Secular variation trend of the fitted values of daily ARMA models.</p>
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<p>Secular variation trend of the fitted values of monthly ARMA models.</p>
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63 pages, 50246 KiB  
Article
Petrogenesis of an Episyenite from Iwagi Islet, Southwest Japan: Unique Li–Na Metasomatism during the Turonian
by Teruyoshi Imaoka, Sachiho Akita, Tsuyoshi Ishikawa, Kenichiro Tani, Jun-Ichi Kimura, Qing Chang and Mariko Nagashima
Minerals 2024, 14(9), 929; https://doi.org/10.3390/min14090929 (registering DOI) - 11 Sep 2024
Abstract
A unique Li–Na metasomatic rock from Iwagi Islet in Southwest (SW) Japan is an episyenite that contains new Li-rich minerals, including sugilite, katayamalite, murakamiite, and ferro-ferri-holmquistite. We present petrographical, mineralogical, and geochronological data for the protoliths and episyenite. We classified the metasomatic rocks [...] Read more.
A unique Li–Na metasomatic rock from Iwagi Islet in Southwest (SW) Japan is an episyenite that contains new Li-rich minerals, including sugilite, katayamalite, murakamiite, and ferro-ferri-holmquistite. We present petrographical, mineralogical, and geochronological data for the protoliths and episyenite. We classified the metasomatic rocks based on the mineral assemblages, from the protolith biotite granite to albitized granite, quartz albitite, hedenbergite albitite, aegirine albitite, sugilite albitite, and katayamalite albitite. The protolith of hedenbergite albitites may have been metasomatic granite that has been subjected to calcic skarnization. Albitites are formed related to fractures and shear zones that focused the fluid flow and metasomatism. Extensive albitization and formation of abundant Li minerals requires involvement of external Li-Na-Cl-rich fluids, which might be related to deep high-temperature Arima-like brines derived from dehydration of the subducted oceanic slab. Formation of the albitites began with quartz dissolution and vug formation, and record interface-coupled dissolution–reprecipitation processes in an open system. The 40Ar/39Ar age of 91.5 ± 0.3 Ma determined for the katayamalite is slightly younger than the protolith zircon U–Pb age of 93.5 ± 1.7 Ma (Turonian), reasonably explaining the timing of Li–Na metasomatism after the petrogenesis of host granites. Full article
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<p>Distribution of episyenite-like rocks in SW Japan (partly modified from Murakami [<a href="#B16-minerals-14-00929" class="html-bibr">16</a>]). 1. Yamada, Osaka Prefecture; 2. Shodoshima Island, Kagawa Prefecture; 3. Innoshima Island, Hiroshima Prefecture; 4. Iwagi Islet, Ehime Prefecture; 5. Hatohama, Ehime Prefecture; 6. Namikata, Ehime Prefecture; 7. Kure, Hiroshima Prefecture; 8. Nomijima Island, Hiroshima Prefecture; 9. Saeki, Hiroshima Prefecture; 10. Aio, Yamaguchi Prefecture; 11. Utsugiono, Yamaguchi Prefecture.</p>
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<p>(<b>a</b>) Geological map of Iwagi Islet, Ehime Prefecture, Japan (after Imaoka et al. [<a href="#B24-minerals-14-00929" class="html-bibr">24</a>]). (<b>b</b>) Enlarged view of the area around Mount Kuresaka showing the occurrence of small masses of albitites.</p>
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<p>(<b>a</b>) Field relationships between the biotite granite, albitized granite, and quartz albitite on the eastern slope of Mount Kuresaka. (<b>b</b>) A close-up of the rectangular area shown in the photograph (<b>a</b>), showing the relationship between albitized granite and quartz albitite. The amount of quartz decreases from left to right in the photograph.</p>
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<p>(<b>a</b>) Na<sub>2</sub>O vs. K<sub>2</sub>O content and (<b>b</b>) Na<sub>2</sub>O vs. Li content.</p>
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<p>SEM image of quartz albitite. Numerous pores of various shapes and sizes are evident.</p>
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<p>Photographs of polished slabs of the major rock types observed around Mount Kuresaka in Iwagi Islet. The scale bar is 1 cm long.</p>
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<p>Modal compositions of the host granite and various albitites.</p>
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<p>Abundance and paragenetic sequence of albitites in Iwagi Islet. Mineral names and their chemical formulae have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (CNMNC IMA), and were taken from the RRUFF website [<a href="#B36-minerals-14-00929" class="html-bibr">36</a>].</p>
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<p>Photomicrograph (plane-polarized light) of the biotite granite. Afs = alkali–feldspar; Pl = plagioclase; Qz = quartz; Bt = biotite; Zrn = zircon.</p>
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<p>Back-scattered electron images of the protolith granite. (<b>a</b>) Typical biotite granite. (<b>b</b>) Symplectic intergrowths of biotite (Bt), quartz (Qz), and alkali feldspar (Afs) in a biotite granite. Pl = plagioclase.</p>
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<p>Back-scattered electron images of accessory minerals in the protolith granite. (<b>a</b>) Euhedral zircon (Zrn) containing abundant thorite/huttonite inclusions. (<b>b</b>) Uranothorite (U-Thr) in thorite (Thr), which is further surrounded by zircon and an Fe–Si mineral. (<b>c</b>) Monazite-(Ce) (Mnz) partially surrounding zircon.</p>
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<p>Back-scattered electron images of accessory minerals in the protolith granite. (<b>a</b>) Allanite (Aln) with oscillatory zoning that contains zircon (Zrn). (<b>b</b>) Ilmenite (Ilm) along a biotite (Bt) cleavage. (<b>c</b>) Xenotime-(Y) (Xtm) along fractures in plagioclase (Pl).</p>
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<p>Back-scattered electron images of accessory minerals in the protolith granite. (<b>a</b>) Fluorapatite with monazite-(Ce) (Mnz) and xenotime-(Y) (Xtm) in quartz (Qz). (<b>b</b>) Fergusonite (Fgs) in plagioclase (Pl). (<b>c</b>) Cassiterite (Cat) in plagioclase.</p>
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<p>Photomicrographs (cross-polarized light) of characteristic minerals in the albitized granite. (<b>a</b>) Blue acicular ferro-ferri-holmquistite (Hlm) in K-feldspar (Kfs), and (<b>b</b>) granular aggregate of aegirine-augite (Aeg-Aug). Qz = quartz.</p>
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<p>Back-scattered electron images of alkali feldspar replaced by albite. (<b>a</b>) Alkali feldspar (Afs) replaced by a patchwork of albite (Ab). (<b>b</b>) K-feldspar (Kfs) remaining in albite that is replaced in a worm-like manner from the outside and inside. Pl = plagioclase; Qz = quartz.</p>
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<p>Back-scattered electron image of biotite (Bt) with symplectic intergrowths with K-feldspar (Kfs) and quartz (Qz).</p>
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<p>Back-scattered electron images of biotite replaced by albite and ferro-ferri-holmquistite. (<b>a</b>) Partial replacement of biotite (Bt) by albite (Ab). (<b>b</b>) Ferro-ferri-holmquistite (Hlm) replacing chloritized biotite. Afs = alkali feldspar.</p>
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<p>Back-scattered electron images of accessory minerals in albitized granite. (<b>a</b>) Zircon (Zrn) and thorite (Thr)/huttonite (Ht). (<b>b</b>) Baddeleyite along fractures in quartz (Qz) and K-feldspar (Kfs). (<b>c</b>) Enlarged view of (<b>b</b>).</p>
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<p>Back-scattered electron images of accessory minerals in albitized granite. (<b>a</b>) Polylithionite (Pln) in K-feldspar (Kfs). (<b>b</b>) Fluorbritholite-(Ce) (Bri) partially enclosing fluorapatite (Fap). (<b>c</b>) Monazite-(Ce)(Mnz) as granular aggregates in biotite (Bt) and quartz (Qz).</p>
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<p>Back-scattered electron images of accessory minerals in albitized granite. (<b>a</b>) Rod-shaped katayamalite (Kyl) in quartz (Qz). (<b>b</b>) Hedenbergite (Hd) in quartz. (<b>c</b>) Turkestanite (Tkt) and fluorbritholite-(Ce) (Bri) in quartz. (<b>d</b>) Arapovite (Apv) in albite (Ab).</p>
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<p>Back-scattered electron image of a vug containing rounded K-feldspar (Kfs) grains connecting Ti-rich veins, and color maps showing the contents of Si, K, and Ti. Afs = alkali feldspar and Ab = albite.</p>
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<p>Back-scattered electron image of a vug containing residual titanite (Ttn) and Ti-rich veins, as well as Si- and Al-bearing materials in the voids, along with color maps of the Al, Ti, and Si contents. Ab = albite and Afs = alkali feldspar.</p>
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<p>Back-scattered electron images of veinlets in albitized granite. (<b>a</b>) Cerium-rich (55.4 wt.% Ce<sub>2</sub>O<sub>3</sub>) veinlet between alkali feldspar (Afs) and quartz (Qz) as indicated by the white arrow. Albite perthites occur in the alkali feldspar. (<b>b</b>) Cerium-rich (52.0 wt.% Ce<sub>2</sub>O<sub>3</sub>) veinlets along polygonal fractures developed in quartz. Large and small pores occur in quartz.</p>
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<p>Back-scattered electron images of accessory minerals in quartz albitite. (<b>a</b>) Hafnium-rich zircon (Zrn) in K-feldspar (Kfs). (<b>b</b>) Vermicular monazite-(Nd) (Mnz) replaced by fluorapatite (Fap) in quartz. (<b>c</b>) Gittinsite (Git) in albite (Ab).</p>
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<p>Back-scattered electron images of vugs containing intergrowths of elongated zircons (Zrn) in albite (Ab). (<b>a</b>) Intergrowth of elongated zircons and Zr-rich titanite (Ttn). (<b>b</b>) Intergrowth of elongate zircons and quartz (Qz).</p>
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<p>Back-scattered electron image of a vug containing fluorapatite (Fap), K-feldspar (Kfs), and monazite (Mnz) in albite (Ab).</p>
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<p>Back-scattered electron images of rectangular and curved veinlets that are several microns wide in quartz albitite. The veinlets contain mainly Si, Na, Mn, and REEs. (<b>a</b>) Silica–Y–Ce vein in albite (Ab). (<b>b</b>) Silica–Al–Na–Ce vein in albitite.</p>
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<p>Back-scattered electron images of polygonal albite and minerals in the hedenbergite albitite. (<b>a</b>) Neoblasts of euhedral albite (Ab) crystals and “fluffy” crystals that project into the vug. (<b>b</b>) Isolated grain of hedenbergite (Hd). (<b>c</b>) Euhedral magnetite (Mag) in albite. Magnetite occurs only in the hedenbergite albitites.</p>
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<p>Back-scattered electron images of Sn-rich titanite (Ttn) and color maps of Ca and Sn contents. Qz = quartz, Zrn = zircon, and Ab = albite.</p>
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<p>Back-scattered electron images of titanite (Ttn), andradite (Adr), and albite (Ab), and color maps of Ca, Fe, and Ti contents.</p>
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<p>Back-scattered electron images of wollastonite (Wo), pectolite (Pct), quartz (Qz), and albite (Ab), and color maps of Si, Ca, and Fe contents.</p>
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<p>Back-scattered electron images of kristiansenite (Ksa) in albite (Ab) and quartz (Qz), and color maps of Ca, Sn, and Fe contents.</p>
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<p>Back-scattered electron images of a vug filled by quartz (Qz) and titanite (Ttn) in albite (Ab), and color maps of Si, Ti, and Ca contents. Aeg-Aug = Aegirine-augite.</p>
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<p>Polished slab (sample IW-90) showing the gradual transition from (<b>a</b>) aegirine albitite to (<b>b</b>) sugilite albitite, and (<b>c</b>) katayamalite albitite. Aegirine albitite in this specimen is characterized by a small amount of colored minerals (aegirine content = 0.2 vol.%). Each albitite is heterogeneous textually and mineralogically.</p>
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<p>Photomicrograph (cross-polarized light) of cross-hatched twinning in an aegirine albitite. Ab = albite and Kfs = K-feldspar.</p>
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<p>Back-scattered electron images of silica minerals in an aegirine albitite. (<b>a</b>) Original magmatic quartz that was dissolved, and in which opal (Opl) with a string-like or rounded irregular shape and opalized quartz (SiO<sub>2</sub>∙nH<sub>2</sub>O) occurs. (<b>b</b>) Rectangular quartz (Qz) containing abundant aegirine-augite (Aeg-Aug) of variable size. Ab = albite.</p>
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<p>Back-scattered electron images of aegirine–augite (Aeg-Aug) and aegirine (Aeg), and color maps of Mg, Na, and Ca contents. Ab = albite.</p>
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<p>Back-scattered electron images of rare accessory minerals in an aegirine albitite. (<b>a</b>) Zircon (Zrn) replaced by zekzerite (Zek). (<b>b</b>) Tainiolite (Tai) in quartz (Qz) and albite (Ab). (<b>c</b>) Dalyite (Dly) in albite.</p>
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<p>Back-scattered electron image of truscottite (Trt) filling an interstitial space of aegirine (Aeg).</p>
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<p>Back-scattered electron image and color map of Ti contents in a vug filled with Ti-rich material and small amounts of aegirine (Aeg). Ab = albite, and Kfs = K-feldspar.</p>
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<p>(<b>a</b>) Microscopic photo of sugilite (Sug), aegirine (Aeg) and albite (Ab), (<b>b</b>) Photomicrograph (cross-polarized light) of bent albite (Ab) in sugilite albitite.</p>
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<p>Back-scattered electron images of minerals in the sugilite albitites. (<b>a</b>) Euhedral aegirine in K-feldspar (Kfs) and albite (Ab), (<b>b</b>) fluorapatite (Fap), (<b>c</b>) turkestanite (Tkt), and (<b>d</b>) botryoidal opal (SiO<sub>2</sub>∙nH<sub>2</sub>O; Opl) in a vug. Qz = quartz.</p>
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<p>Sugilite (Sug), aegirine (Aeg), and opalized quartz (Qz) infilling the red dashed rectangle vug. Opalized quartz remains around the vug, indicating that quartz originally existed in the vug.</p>
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<p>Color maps of Si and Na contents in the vug shown in <a href="#minerals-14-00929-f043" class="html-fig">Figure 43</a>. The vug is filled with sugilite, aegirine, and opalized quartz.</p>
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<p>(<b>a</b>) Photomicrograph (cross-polarized light) of murakamiite in the katayamalite albitite (partly modified from Imaoka at al. [<a href="#B24-minerals-14-00929" class="html-bibr">24</a>]). Mkm = murakamiite; Aeg-Aug = aegirine-augite; p = pore in albitite; Ab1 = large subhedral crystal of albite with or without simple twinning; Ab2 = large anhedral albite with fine polysynthetic and cross-hatched twinning; Ab3 = aggregates of small, clear, newly formed granular albite crystals at the boundaries of larger albite grains. (<b>b</b>) Photomicrograph (cross-polarized light) of albite types Ab1, Ab2, and Ab3. (<b>c</b>) Photomicrograph (cross-polarized light) of albite types Ab2 and Ab4. Ab4 = albite exhibiting undulose extinction and deformation twins.</p>
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<p>Photomicrograph (cross-polarized light) of deformation microstructures in albite (Ab). The albite twins are slightly offset.</p>
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<p>Back-scattered electron image and color maps of Si, Ca, and K contents of katayamalite (Kyl), sugilite (Sug), and pectolite–murakamiite (Pet–Mkm). Ab = albite and Aeg = aegirine.</p>
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<p>Back-scattered electron images of minerals and textures in the katayamalite albitite. (<b>a</b>) Aegirine-augite (Aeg-Aug) that appears to have formed along cracks in albite (Ab). (<b>b</b>) Calcite (Cal) veins and pools.</p>
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<p>Back-scattered electron images showing the relationships between wollastonite (Wo), pectolite–murakamiite (Pct–Mkm), and calcite (Cal). (<b>a</b>) Needle-shaped or fibrous aggregates of wollastonite in pectolite–murakamiite. (<b>b</b>) Pectolite–murakamiite replaced by calcite. (<b>c</b>) Veins of calcite in pectolite–murakamiite. Fap = fluorapatite, Aeg-Aug = aegirine augite, Qz = quartz, Ab = albite and Sug = sugilite.</p>
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<p>Q–J diagram by Morimoto et al. [<a href="#B42-minerals-14-00929" class="html-bibr">42</a>]. This figure shows that Ca + Mg + Fe<sup>2+</sup> is replaced by Na. The areas corresponding to the Ca–Mg–Fe pyroxenes, Ca–Na pyroxenes, and Na pyroxenes, are labeled in this diagram as Quad, Ca–Na, and Na, respectively.</p>
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<p>Clinopyroxene data plotted on Q (Wo + En + Fs)–Jd–Ae ternary diagrams.</p>
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<p>Normal U–Pb concordia diagrams. Red circles indicate one-sigma error ellipsoids including error correlations between <sup>206</sup>Pb/<sup>238</sup>U and <sup>207</sup>Pb/<sup>235</sup>U for individual spots. Errors in decay constants are also propagated. Blue circles show the same with average values and one-sigma errors from individual spots. (<b>a</b>) Protolith coarse-grained biotite granite (sample T-69). (<b>b</b>) Medium-grained granite (sample IW-300). (<b>c</b>) Fine-grained granite (sample IW-303). (<b>d</b>) All granites (T-69, IW-300, and IW-303).</p>
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<p><sup>40</sup>Ar/<sup>39</sup>Ar age spectra of katayamalite in albitite (sample IWG-168a).</p>
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<p>Normal isochron diagram.</p>
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<p>Inverse isochron diagram.</p>
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<p>A simple model diagram showing the leading front and albitite arrangement at the final, most advanced stage.</p>
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21 pages, 7061 KiB  
Article
Logistics Transportation Vehicle Supply Forecasting Based on Improved Informer Modeling
by Dudu Guo, Peifan Jiang, Yin Qin, Xue Zhang and Jinquan Zhang
Appl. Sci. 2024, 14(18), 8162; https://doi.org/10.3390/app14188162 - 11 Sep 2024
Abstract
This study focuses on the problem of the supply prediction of logistics transportation vehicles in road transportation. Aiming at the problem that the supply data of logistics transportation has the characteristics of long sequential data, numerous influencing factors, and a significant spatiotemporal evolution [...] Read more.
This study focuses on the problem of the supply prediction of logistics transportation vehicles in road transportation. Aiming at the problem that the supply data of logistics transportation has the characteristics of long sequential data, numerous influencing factors, and a significant spatiotemporal evolution law, which leads to the lack of accuracy of supply predictions, this paper proposes a supply prediction method for logistics transportation based on an improved Informer model. Firstly, multidimensional feature engineering is applied to historical supply data to enhance the interpretability of labeled data. Secondly, a spatiotemporal convolutional network is designed to extract the spatiotemporal features of the supply volume. Lastly, a long short-term memory (LSTM) model is introduced to capture the supply volume’s long- and short-term dependencies, and the predicted value is derived through a multilayer perceptron. The experimental results show that mean square error (MSE) is reduced by 73.8%, 79.36%, 82.24%, 78.58%, 77.02%, 53.96%, and 40.38%, and mean absolute error (MAE) is reduced by 52%, 59.5%, 60.36%, 57.52%, 53.9%, 31.21%, and 36.58%, respectively, when compared to the auto-regressive integrated moving average (ARIMA), support vector regression (SVR), LSTM, gated recurrent units (GRUs), a back propagation neural network (BPNN), and Informer and InformerStack single models; compared with the ARIMA + BPNN, ARIMA + GRU and ARIMA + LSTM integrated models, the MSE is reduced by 74.88%, 71.56%, and 74.07%, respectively, and the MAE is reduced by 51.31%, 50%, and 52.02%; it effectively reduces the supply prediction error and improves the prediction accuracy. Full article
(This article belongs to the Special Issue Data Science and Machine Learning in Logistics and Transport)
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<p>Self-attentive distillation mechanism.</p>
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<p>Position encoding.</p>
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<p>Spatiotemporal convolutional network (STCN module).</p>
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<p>LSTM block.</p>
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<p>Improvement of Informer model structure.</p>
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<p>Evolution of supply and freight rates. (<b>a</b>) Chart of time series changes in supply and (<b>b</b>) chart of changes in the chronology of freight costs.</p>
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<p>Pearson correlation analysis chart.</p>
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<p>Multidimensional feature engineering of data.</p>
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<p>Results of single model comparison experiment. (<b>a</b>) support vector regression (SVR) model; (<b>b</b>) long short-term memory (LSTM) model; (<b>c</b>) gated recurrent units (GRUs) model; (<b>d</b>) back propagation neural network (BPNN) model; (<b>e</b>) Informer model; and (<b>f</b>) InformerStack model.</p>
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<p>Experimental results of integrated model comparison. (<b>a</b>) ARIMA + BPNN model; (<b>b</b>) ARIMA + GRU model; and (<b>c</b>) ARIMA + LSTM model.</p>
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<p>Results of single model comparison experiment (ETTh1). (<b>a</b>) SVR model; (<b>b</b>) LSTM model; (<b>c</b>) GRU model; (<b>d</b>) BPNN model; (<b>e</b>) Informer model; and (<b>f</b>) InformerStack model.</p>
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<p>Experimental results of integrated model comparison (ETTH1). (<b>a</b>) ARIMA + BPNN model; (<b>b</b>) ARIMA + GRU model; and (<b>c</b>) ARIMA + LSTM model.</p>
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14 pages, 6052 KiB  
Article
Exploring Carbon Emission Reduction in Inland Port Ship Based on a Multi-Scenario Model
by Chunhui Zhou, Wuao Tang, Zongyang Liu, Hongxun Huang, Liang Huang, Changshi Xiao and Lichuan Wu
J. Mar. Sci. Eng. 2024, 12(9), 1553; https://doi.org/10.3390/jmse12091553 - 5 Sep 2024
Viewed by 265
Abstract
Assessing carbon emission reduction potential is vital for achieving carbon peak and neutrality in the maritime sector. In this study, we proposed a universal framework for assessing the effectiveness of different measures on carbon emission reduction from ships, including port and ship electrification [...] Read more.
Assessing carbon emission reduction potential is vital for achieving carbon peak and neutrality in the maritime sector. In this study, we proposed a universal framework for assessing the effectiveness of different measures on carbon emission reduction from ships, including port and ship electrification (PSE), ship speed optimization (SSO), and clean fuel substitution (CFS). Firstly, the projection method of future ship traffic flows and activity levels relies on a neural network, and the ARIMA model was proposed. Then, the potential of various emission reduction measures was detailed and analyzed under different intensity scenarios. The proposed model was applied to Wuhan port, the results indicate that CFS is the most effective for long-term decarbonization, potentially achieving a carbon peak by 2025 under an aggressive scenario. For the short to medium term, PSE is favored due to technical maturity. SSO primarily delays emissions growth, making it a suitable auxiliary measure. These findings guide emission reduction strategies for ports, fostering green and sustainable shipping development. Full article
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<p>Framework of ship carbon emission reduction assessment model.</p>
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<p>The Wuhan port layout [<a href="#B39-jmse-12-01553" class="html-bibr">39</a>].</p>
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<p>Comparison of predicted and actual ship traffic flow values.</p>
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<p>Comparison of the predicted and actual values of the activity level elements of the sample ships.</p>
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<p>Distribution of arriving ship activity flow among different port areas.</p>
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<p>Distribution of harbor ship activity flow among different port areas.</p>
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<p>Carbon emission reduction of different port areas in 2030 under PSE scenario.</p>
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<p>Trends in CO<sub>2</sub> emissions from ships under different future emission reduction scenarios. (<b>a</b>) PSE scenarios (<b>b</b>) CFS scenarios (<b>c</b>) SSO scenarios.</p>
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<p>Emission reduction rates for each abatement strategy under different scenarios.</p>
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16 pages, 2325 KiB  
Article
Forecasting the Evolution of the Digital Economy in the Industry of the European Union
by Iordanis Karavasilis, Vasiliki Vrana and George Karavasilis
J. Risk Financial Manag. 2024, 17(9), 393; https://doi.org/10.3390/jrfm17090393 - 4 Sep 2024
Viewed by 577
Abstract
The wide use of telecommunications, computers and the internet, especially over the last four decades, has formed a new economic phenomenon, the “Digital Economy”. As a matter of facts, the development of digitalization has raised questions about its contribution to official economic indicators. [...] Read more.
The wide use of telecommunications, computers and the internet, especially over the last four decades, has formed a new economic phenomenon, the “Digital Economy”. As a matter of facts, the development of digitalization has raised questions about its contribution to official economic indicators. This research examines the evolution of the information and communication industry (ICI) and its contribution to the national Gross Domestic Product (GDP) of six European entities. Time series and auto-ARIMA models are employed to process the data. Moreover, this study forecasts the development of the ICI in the future. The results demonstrate a clear stable growth in the variable under examination over time, showing an increasingly greater contribution of the ICI to the national GDP in most cases with the exception of Greece, which has a high provisional risk. Full article
(This article belongs to the Section Financial Technology and Innovation)
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<p>Time series plots of the information and communication industry (ICI) index for the 27 members of the E.U., Czechia, Sweden, Germany, Austria and Greece.</p>
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<p>Box plots of the information and communication industry (ICI) index for the 27 members of the E.U., Czechia, Sweden, Germany, Austria and Greece.</p>
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<p>Correlograms of the information and communication industry (ICI) index for the 27 members of the E.U., Czechia, Sweden, Germany, Austria and Greece.</p>
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<p>ARIMA fitted models and forecast of the ICI index for the 27 members of the E.U. (θ<sub>1</sub> = −0.6279), Czechia (φ<sub>1</sub> = −0.5167), Sweden (θ<sub>1</sub> = −0.8226), Germany (c = 3.7811), Austria (c = 3.0755) and Greece (φ<sub>1</sub> = 1.8759, φ<sub>2</sub> = −0.9508, φ<sub>3</sub> = −0.0038, θ<sub>1</sub> = 0.7607 and c = 9.4255).</p>
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<p>Time series plot, correlogram and the histogram of the residuals of the fitted model for the 27 members of the E.U.</p>
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<p>Time series plot, correlogram and histogram of the residuals of the fitted model for Czechia.</p>
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<p>Time series plot, correlogram and histogram of the residuals of the fitted model for Greece.</p>
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27 pages, 2771 KiB  
Article
Contextual Intelligence: An AI Approach to Manufacturing Skills’ Forecasting
by Xolani Maphisa, Mpho Nkadimeng and Arnesh Telukdarie
Big Data Cogn. Comput. 2024, 8(9), 101; https://doi.org/10.3390/bdcc8090101 - 2 Sep 2024
Viewed by 901
Abstract
The manufacturing industry is skill-intensive and plays a pivotal role in South Africa’s economy, reflecting the nation’s progress and development. The advent of technology has initiated a transformative era within the manufacturing sector. Workforce skills are at the heart of ensuring the sustained [...] Read more.
The manufacturing industry is skill-intensive and plays a pivotal role in South Africa’s economy, reflecting the nation’s progress and development. The advent of technology has initiated a transformative era within the manufacturing sector. Workforce skills are at the heart of ensuring the sustained growth of the industry. This study delves into the skill-related aspects of the occupational landscape of the South African manufacturing sector, with a particular focus on two important manufacturing sectors: the food and beverage manufacturing (FoodBev) sector and the chemical manufacturing (CHIETA) sector. Leveraging the forecasting prowess of Autoregressive Integrated Moving Average (ARIMA), this paper outlines a sectorial occupational forecasting modeling exercise to reveal which job roles are poised for expansion and which are expected to decline. The approach predicted future skills’ demand 80% accuracy for 473 out of 713 (66%) occupations for FoodBev and 474 out of 522 (91%) for CHIETA. These insights are invaluable for industry stakeholders and educational institutions, providing guidance to support the sector’s growth in an era marked by technological advancement. Full article
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<p>DDDM.</p>
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<p>Process diagram for (<span class="html-italic">p</span>, <span class="html-italic">d</span>, <span class="html-italic">q</span>) parameter selection.</p>
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<p>Methodology flow diagram.</p>
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<p>Missing values.</p>
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<p>Educational levels of employees in the chemical sector 2019–2022.</p>
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<p>Occupational interface—trend tab.</p>
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<p>Occupational interface—trend tab.</p>
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<p>Forecast tab.: The blue region in the plot represents the prediction interval boundaries for the forecasted values, specifically encompassing the 50% and 95% prediction intervals, with a central dot marking the point forecast, which is the ARIMA model’s estimate for the expected value. The ACF and PACF plots (blue dotted lines) illustrate the autocorrelation function and partial autocorrelation function of the residuals, which are crucial for diagnosing the fit of the ARIMA model by showing the correlation of residuals at different lags. The yellow curve (subplot 2 and 4) represents a normal distribution, which indicates how the residuals (the differences between observed and predicted values) are distributed around the zero mean.</p>
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<p>Forecast tab.: The blue region in the plot represents the prediction interval boundaries for the forecasted values, specifically encompassing the 50% and 95% prediction intervals, with a central dot marking the point forecast, which is the ARIMA model’s estimate for the expected value. The ACF and PACF plots (blue dotted lines) illustrate the autocorrelation function and partial autocorrelation function of the residuals, which are crucial for diagnosing the fit of the ARIMA model by showing the correlation of residuals at different lags. The yellow curve (subplot 2 and 4) represents a normal distribution, which indicates how the residuals (the differences between observed and predicted values) are distributed around the zero mean.</p>
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28 pages, 525 KiB  
Article
Evaluating the Effectiveness of Time Series Transformers for Demand Forecasting in Retail
by José Manuel Oliveira and Patrícia Ramos
Mathematics 2024, 12(17), 2728; https://doi.org/10.3390/math12172728 - 31 Aug 2024
Viewed by 362
Abstract
This study investigates the effectiveness of Transformer-based models for retail demand forecasting. We evaluated vanilla Transformer, Informer, Autoformer, PatchTST, and temporal fusion Transformer (TFT) against traditional baselines like AutoARIMA and AutoETS. Model performance was assessed using mean absolute scaled error (MASE) and weighted [...] Read more.
This study investigates the effectiveness of Transformer-based models for retail demand forecasting. We evaluated vanilla Transformer, Informer, Autoformer, PatchTST, and temporal fusion Transformer (TFT) against traditional baselines like AutoARIMA and AutoETS. Model performance was assessed using mean absolute scaled error (MASE) and weighted quantile loss (WQL). The M5 competition dataset, comprising 30,490 time series from 10 stores, served as the evaluation benchmark. The results demonstrate that Transformer-based models significantly outperform traditional baselines, with Transformer, Informer, and TFT leading the performance metrics. These models achieved MASE improvements of 26% to 29% and WQL reductions of up to 34% compared to the seasonal Naïve method, particularly excelling in short-term forecasts. While Autoformer and PatchTST also surpassed traditional methods, their performance was slightly lower, indicating the potential for further tuning. Additionally, this study highlights a trade-off between model complexity and computational efficiency, with Transformer models, though computationally intensive, offering superior forecasting accuracy compared to the significantly slower traditional models like AutoARIMA. These findings underscore the potential of Transformer-based approaches for enhancing retail demand forecasting, provided the computational demands are managed effectively. Full article
(This article belongs to the Special Issue Artificial Intelligence and Data Science)
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<p>Transformer model architecture. The encoder component, positioned on the left, processes the input generating a latent representation. The decoder component, positioned on the right, leverages this representation to produce the output in an autoregressive manner. This means that the decoder iteratively generates output elements, using previously produced elements as additional input for subsequent predictions.</p>
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<p>Model training using a validation set split and model evaluation using cross-validation.</p>
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<p>Relative MASE (<b>left</b>) and WQL (<b>right</b>) for Transformer-based models and baselines compared to the seasonal Naïve method over the 1–28-day forecast horizon.</p>
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<p>Training and prediction times for Transformer-based models using MAE and MQLoss, alongside baseline methods. The bar plot shows the computational efficiency of Transformer models and baselines, comparing the time required for training and prediction.</p>
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<p>Point forecasts (<b>left</b>) and probabilistic forecasts (<b>right</b>) for an example series.</p>
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20 pages, 4755 KiB  
Article
Advanced Defect Detection in Wrap Film Products: A Hybrid Approach with Convolutional Neural Networks and One-Class Support Vector Machines with Variational Autoencoder-Derived Covariance Vectors
by Tatsuki Shimizu, Fusaomi Nagata, Maki K. Habib, Koki Arima, Akimasa Otsuka and Keigo Watanabe
Machines 2024, 12(9), 603; https://doi.org/10.3390/machines12090603 - 31 Aug 2024
Viewed by 361
Abstract
This study proposes a novel approach that utilizes Convolutional Neural Networks (CNNs) and Support Vector Machines (SVMs) to tackle a critical challenge: detecting defects in wrapped film products. With their delicate and reflective film wound around a core material, these products present formidable [...] Read more.
This study proposes a novel approach that utilizes Convolutional Neural Networks (CNNs) and Support Vector Machines (SVMs) to tackle a critical challenge: detecting defects in wrapped film products. With their delicate and reflective film wound around a core material, these products present formidable hurdles for conventional visual inspection systems. The complex task of identifying defects, such as unwound or protruding areas, remains a daunting endeavor. Despite the power of commercial image recognition systems, they struggle to capture anomalies within wrap film products. Our research methodology achieved a 90% defect detection accuracy, establishing its practical significance compared with existing methods. We introduce a pioneering methodology centered on covariance vectors extracted from latent variables, a product of a Variational Autoencoder (VAE). These covariance vectors serve as feature vectors for training a specialized One-Class SVM (OCSVM), a key component of our approach. Unlike conventional practices, our OCSVM does not require images containing defects for training; it uses defect-free images, thus circumventing the challenge of acquiring sufficient defect samples. We compare our methodology against feature vectors derived from the fully connected layers of established CNN models, AlexNet and VGG19, offering a comprehensive benchmarking perspective. Our research represents a significant advancement in defect detection technology. By harnessing the latent variable covariance vectors from a VAE encoder, our approach provides a unique solution to the challenges faced by commercial image recognition systems. These advancements in our study have the potential to revolutionize quality control mechanisms within manufacturing industries, offering a brighter future for product integrity and customer satisfaction. Full article
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<p>Training image samples without defects.</p>
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<p>The proposed cascade-type OCSVMs for classifying images into OK or NG categories, employing AlexNet-based, VGG19-based, and VAE-based OCSVMs.</p>
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<p>Three reconstructed results in the case of three test images without a defect given to the VAE.</p>
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<p>Three reconstructed results given in the case of three test images, including defects.</p>
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<p>Configuration of the proposed One-Class learning-based SVM with a VAE for feature extraction.</p>
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<p>Original examples of normal and anomaly images before the template matching process.</p>
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<p>Configuration of the proposed One-Class SVM with AlexNet for feature extraction.</p>
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<p>Our developed application provides a selection function for one of the powerful CNN models to design an SVM.</p>
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<p>Configuration of the proposed One-Class SVM with VGG19 for feature extraction.</p>
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<p>Examples of anomaly images after the template matching process.</p>
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19 pages, 9035 KiB  
Article
Experimental Research on Prediction of Remaining Using Life of Solar DC Centrifugal Pumps Based on ARIMA Model
by Qin Hu, Jianbao Wang, Jing Xiong, Meng Zhang, Hua Fu, Ji Pei and Wenjie Wang
Processes 2024, 12(9), 1857; https://doi.org/10.3390/pr12091857 - 30 Aug 2024
Viewed by 324
Abstract
In order to improve the stability and reliability of the solar DC centrifugal pump real-time operation and prevent the centrifugal pump failure caused by the unexpected shutdown of the system, a set of accurate and efficient centrifugal pump condition monitoring systems was built. [...] Read more.
In order to improve the stability and reliability of the solar DC centrifugal pump real-time operation and prevent the centrifugal pump failure caused by the unexpected shutdown of the system, a set of accurate and efficient centrifugal pump condition monitoring systems was built. A time series-based strategy for predicting the remaining using life (RUL) of centrifugal pumps was proposed. The time series of head and efficiency of centrifugal pumps at specific flow conditions were measured, the corresponding failure thresholds were set, and different differential autoregressive integrated moving average (ARIMA) models were developed to predict the remaining useful life of the pumps. The results show that the maximum prediction error of the head ARIMA model established under the design conditions of the pump was 0.040%, and the head time series reaches the failure threshold of 8 m at the 653rd data point; the maximum prediction error of the efficiency ARIMA model was 0.042%, and the efficiency time series reaches the failure threshold of 16% at the 672nd data point. According to the proposed prediction strategy, the RUL of the centrifugal pump under the design condition was 53 h. The head time series of the pump at high flow conditions reaches a failure threshold of 5 m at the 640th data point; the efficiency time series will reach a failure threshold of 12.5% at the 578th data point, and the RUL of the centrifugal pump at high flow conditions was 78 h. The established ARIMA model has a high prediction accuracy and can effectively predict the RUL of centrifugal pumps. Full article
(This article belongs to the Special Issue Multiphase Flow and Optimal Design in Fluid Machinery)
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<p>Diagram of the solar water pumping system.</p>
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<p>Complete pumping system design (<b>a</b>) Block diagram of the overall system design, (<b>b</b>) Three-dimensional view of a centrifugal pump.</p>
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<p>Physical view of the test stand.</p>
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<p>Block diagram of the data acquisition procedure.</p>
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<p>Flow–head/efficiency characteristic curves.</p>
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<p>Time series of head under design conditions.</p>
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<p>Second-order differential head time series for design conditions.</p>
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<p>Function diagram of stable head time series ACF and PACF under design condition.</p>
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<p>Results of training tests with ARIMA model for head under design conditions.</p>
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<p>Time series RUL prediction of head under design conditions.</p>
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<p>Time series of efficiency under design conditions.</p>
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<p>Results of training tests with the ARIMA model for efficiency under design conditions.</p>
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<p>Time series RUL prediction of efficiency under design conditions.</p>
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<p>Time series of head under high flow conditions.</p>
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<p>Results of training tests with the ARIMA model for head under high flow design conditions.</p>
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<p>Time series RUL prediction of head under high flow conditions.</p>
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<p>Time series of efficiency under high flow conditions.</p>
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<p>Results of training tests with the ARIMA model for efficiency under high flow design conditions.</p>
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<p>Time series RUL prediction of efficiency under high flow conditions.</p>
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23 pages, 4788 KiB  
Article
Forecasting of Standardized Precipitation Index Using Hybrid Models: A Case Study of Cape Town, South Africa
by Siphamandla Sibiya, Nkanyiso Mbatha, Shaun Ramroop, Sileshi Melesse and Felix Silwimba
Water 2024, 16(17), 2469; https://doi.org/10.3390/w16172469 - 30 Aug 2024
Viewed by 1048
Abstract
Droughts have negative impacts on agricultural productivity and economic growth. Effective monitoring and accurate forecasting of drought occurrences and trends are crucial for minimizing drought losses and mitigating their spatial and temporal effects. In this study, trend dynamics in monthly total rainfall time [...] Read more.
Droughts have negative impacts on agricultural productivity and economic growth. Effective monitoring and accurate forecasting of drought occurrences and trends are crucial for minimizing drought losses and mitigating their spatial and temporal effects. In this study, trend dynamics in monthly total rainfall time series measured at Cape Town International Airport were analyzed using the Mann–Kendall (MK) test, Modified Mann–Kendall (MMK) test and innovative trend analysis (ITA). Additionally, we utilized a hybrid prediction method that combined the model with the complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN) technique, the autoregressive integrated moving average (ARIMA) model, and the long short-term memory (LSTM) network (i.e., CEEMDAN-ARIMA-LSTM) to forecast SPI values of 6-, 9-, and 12-months using rainfall data between 1995 and 2020 from Cape Town International Airport meteorological rainfall stations. In terms of trend analysis of the monthly total rainfall, the MK and MMK tests detected a significant decreasing trend with negative z-scores of −3.7541 and −4.0773, respectively. The ITA also indicated a significant downward trend of total monthly rainfall, especially for values between 10 and 110 mm/month. The SPI forecasting results show that the hybrid model (CEEMDAN-ARIMA-LSTM) had the highest prediction accuracy of the models at all SPI timescales. The Root Mean Square Error (RMSE) values of the CEEMDAN-ARIMA-LSTM hybrid model are 0.121, 0.044, and 0.042 for SPI-6, SPI-9, and SPI-12, respectively. The directional symmetry for this hybrid model is 0.950, 0.917, and 0.950, for SPI-6, SPI-9, and SPI-12, respectively. This indicates that this is the most suitable model for forecasting long-term drought conditions in Cape Town. Additionally, models that use a decomposition step and those that are built by combining independent models seem to produce improved SPI prediction accuracy. Full article
(This article belongs to the Section Water and Climate Change)
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<p>The study area map. Cape Town International Airport location is indicated by a red star.</p>
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<p>The s schematic representation of the Box–Jenkins methodology application to improve SPI time series forecasting.</p>
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<p>The basic unit structure diagram of the LSTM single cell.</p>
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<p>Schematic structure of the developed hybrid CEEMDAN-ARIMA-LSTM model for time series analysis methodology.</p>
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<p>Time series of the monthly rainfall.</p>
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<p>Innovative trend analysis of monthly total rainfall data measured at Cape Town International Airport meteorological station, South Africa. The blue shaded area represents the 95% confidence level area.</p>
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<p>Sequential Mann–Kendall values of the statistics u(t) (red line) and u’(t) (black line) from the Mann–Kendall test for monthly rainfall measured at Cape Town International Airport for the period from 1995 to 2020.</p>
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<p>Observed SPI values at the 6-, 9-, and 12-month timescales calculated from the rainfall data measured at Cape Point International Airport. The blue and red shades indicate moist and dry conditions.</p>
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<p>The CEEMDAN decomposition results of SPI-6 sequence. The blue and red shades indicate moist and dry conditions.</p>
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<p>The time series of observations and forecasts for the SPI prediction (<b>Bottom</b>) and their Taylor diagram plots at different timescales (<b>Top</b>) (<b>a</b>) SPI-6, (<b>b</b>) SPI-9, and (<b>c</b>) SPI-12.</p>
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27 pages, 4478 KiB  
Article
Predicting Economic Trends and Stock Market Prices with Deep Learning and Advanced Machine Learning Techniques
by Victor Chang, Qianwen Ariel Xu, Anyamele Chidozie and Hai Wang
Electronics 2024, 13(17), 3396; https://doi.org/10.3390/electronics13173396 - 26 Aug 2024
Viewed by 1349
Abstract
The volatile and non-linear nature of stock market data, particularly in the post-pandemic era, poses significant challenges for accurate financial forecasting. To address these challenges, this research develops advanced deep learning and machine learning algorithms to predict financial trends, quantify risks, and forecast [...] Read more.
The volatile and non-linear nature of stock market data, particularly in the post-pandemic era, poses significant challenges for accurate financial forecasting. To address these challenges, this research develops advanced deep learning and machine learning algorithms to predict financial trends, quantify risks, and forecast stock prices, focusing on the technology sector. Our study seeks to answer the following question: “Which deep learning and supervised machine learning algorithms are the most accurate and efficient in predicting economic trends and stock market prices, and under what conditions do they perform best?” We focus on two advanced recurrent neural network (RNN) models, long short-term memory (LSTM) and Gated Recurrent Unit (GRU), to evaluate their efficiency in predicting technology industry stock prices. Additionally, we integrate statistical methods such as autoregressive integrated moving average (ARIMA) and Facebook Prophet and machine learning algorithms like Extreme Gradient Boosting (XGBoost) to enhance the robustness of our predictions. Unlike classical statistical algorithms, LSTM and GRU models can identify and retain important data sequences, enabling more accurate predictions. Our experimental results show that the GRU model outperforms the LSTM model in terms of prediction accuracy and training time across multiple metrics such as RMSE and MAE. This study offers crucial insights into the predictive capabilities of deep learning models and advanced machine learning techniques for financial forecasting, highlighting the potential of GRU and XGBoost for more accurate and efficient stock price prediction in the technology sector. Full article
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<p>Simple RNN with an input circle and its equivalent unrolled presentation.</p>
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<p>The repeating module in a standard RNN contains a single layer.</p>
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<p>The repeating module in an LSTM.</p>
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<p>The internal structure of the GRU model.</p>
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<p>The basic structure of the attention model.</p>
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<p>The methodology framework for this research.</p>
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<p>The architecture diagram for processing and analyzing data.</p>
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<p>The closing price of the technological stock prices selected.</p>
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<p>Apple stock: actual and predicted close price, LSTM and GRU models.</p>
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<p>Google stock: actual and predicted close, LSTM and GRU models.</p>
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<p>Microsoft stock: actual and predicted close price, LSTM and GRU models.</p>
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<p>Amazon stock: actual and predicted close price, LSTM and GRU models.</p>
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<p>Predicted risk–return tradeoff plot.</p>
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20 pages, 7324 KiB  
Article
Water–Energy–Food Nexus in the Yellow River Basin of China under the Influence of Multiple Policies
by Yikun Zhang and Yongsheng Wang
Land 2024, 13(9), 1356; https://doi.org/10.3390/land13091356 - 25 Aug 2024
Viewed by 446
Abstract
The water–energy–food (WEF) nexus constitutes a pivotal aspect of regional ecological protection and high-quality development. The exertion of multiple WEF-related policies would engender both synergies and trade-offs within the WEF nexus. However, a quantified framework that integrates the impact of multiple WEF-related policies [...] Read more.
The water–energy–food (WEF) nexus constitutes a pivotal aspect of regional ecological protection and high-quality development. The exertion of multiple WEF-related policies would engender both synergies and trade-offs within the WEF nexus. However, a quantified framework that integrates the impact of multiple WEF-related policies with conventional WEF nexus assessments and simulations is currently lacking. This study quantified the WEF nexus in the Yellow River basin (YRB) of China under the influence of multiple policies, calculated the current and future WEF scores under different policy combination scenarios using the improved entropy weight method, the auto-regressive integrated moving average (ARIMA) model, and the linear optimization method. The results revealed the following: (1) From 2000 to 2020, WEF overall scores and subsystem scores were substantially increased with spatial heterogeneity. (2) Scenario analysis indicated that policy implementation would generally accelerate WEF score improvements in each city, yet embracing all policies simultaneously was not optimal for each city. (3) The spatial heterogeneity in policy impacts was also found in the YRB, with higher trade-offs in the upper reaches of cities, and higher synergies in the middle and lower reaches of cities. To attain high-quality development within the YRB, the related policies’ implementation should consider the regional disparities and enhance the optimization of resource allocation across the regions. Full article
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<p>Location of the YRB in China (<b>a</b>), natural characteristics of the YRB (<b>b</b>), and city distribution in the YRB (<b>c</b>).</p>
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<p>Policies related to water, energy, and food in the YRB.</p>
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<p>Interaction mechanisms of WEF system.</p>
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<p>Interactive relationships among WEF policies.</p>
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<p>Impacts of WEF policies on indicators.</p>
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<p>Spatial distributions of scores of water subsystem (<b>a1,a2,a3</b>), energy subsystem (<b>b1,b2,b3</b>), food subsystem (<b>c1,c2,c3</b>), and overall score (<b>d1,d2,d3</b>) in the YRB from 2000 to 2020.</p>
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<p>Policy choices in scenario 2 and scenario 3; the dotted cell means the corresponding policy was chosen.</p>
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<p>Difference degree between S1 and S2 (<b>a,b</b>) and S1 and S3 (<b>c,d</b>).</p>
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29 pages, 7562 KiB  
Article
Optimizing Electric Vehicle (EV) Charging with Integrated Renewable Energy Sources: A Cloud-Based Forecasting Approach for Eco-Sustainability
by Mohammad Aldossary, Hatem A. Alharbi and Nasir Ayub
Mathematics 2024, 12(17), 2627; https://doi.org/10.3390/math12172627 - 24 Aug 2024
Viewed by 419
Abstract
As electric vehicles (EVs) are becoming more common and the need for sustainable energy practices is growing, better management of EV charging station loads is a necessity. The simple act of folding renewable power from solar or wind in an EV charging system [...] Read more.
As electric vehicles (EVs) are becoming more common and the need for sustainable energy practices is growing, better management of EV charging station loads is a necessity. The simple act of folding renewable power from solar or wind in an EV charging system presents a huge opportunity to make them even greener as well as improve grid resiliency. This paper proposes an innovative EV charging station energy consumption forecasting approach by incorporating integrated renewable energy data. The optimization is achieved through the application of SARLDNet, which enhances predictive accuracy and reduces forecast errors, thereby allowing for more efficient energy allocation and load management in EV charging stations. The technique leverages comprehensive solar and wind energy statistics alongside detailed EV charging station utilization data collected over 3.5 years from various locations across California. To ensure data integrity, missing data were meticulously addressed, and data quality was enhanced. The Boruta approach was employed for feature selection, identifying critical predictors, and improving the dataset through feature engineering to elucidate energy consumption trends. Empirical mode decomposition (EMD) signal decomposition extracts intrinsic mode functions, revealing temporal patterns and significantly boosting forecasting accuracy. This study introduces a novel stem-auxiliary-reduction-LSTM-dense network (SARLDNet) architecture tailored for robust regression analysis. This architecture combines regularization, dense output layers, LSTM-based temporal context learning, dimensionality reduction, and early feature extraction to mitigate overfitting. The performance of SARLDNet is benchmarked against established models including LSTM, XGBoost, and ARIMA, demonstrating superior accuracy with a mean absolute percentage error (MAPE) of 7.2%, Root Mean Square Error (RMSE) of 22.3 kWh, and R2 Score of 0.87. This validation of SARLDNet’s potential for real-world applications, with its enhanced predictive accuracy and reduced error rates across various EV charging stations, is a reason for optimism in the field of renewable energy and EV infrastructure planning. This study also emphasizes the role of cloud infrastructure in enabling real-time forecasting and decision support. By facilitating scalable and efficient data processing, the insights generated support informed energy management and infrastructure planning decisions under dynamic conditions, empowering the audience to adopt sustainable energy practices. Full article
(This article belongs to the Section Mathematics and Computer Science)
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<p>Proposed framework.</p>
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<p>Total energy consumption per charging station (monthly).</p>
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<p>Average daily and weekly energy consumption.</p>
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<p>Analysis of energy consumption monthly (average of 3 stations). (<b>a</b>) Average monthly energy consumption (all stations); (<b>b</b>) Distribution of energy consumption.</p>
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<p>Energy consumption of PALO-ALTO station. (<b>a</b>) Daily energy consumption of PALO-ALTO station; (<b>b</b>) Monthly energy consumption of PALO-ALTO station.</p>
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<p>Feature importance of selected features using Boruta algorithm.</p>
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<p>EMD of energy consumption (kWh) from 2015 to 2023.</p>
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<p>IMFs from EMD of energy consumption.</p>
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<p>EV charging station forecasts of different periods (averaged).</p>
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<p>Execution time of the proposed and existing method.</p>
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<p>Accuracy of the proposed and existing method.</p>
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30 pages, 1356 KiB  
Article
Machine Learning and Artificial Intelligence for a Sustainable Tourism: A Case Study on Saudi Arabia
by Ali Louati, Hassen Louati, Meshal Alharbi, Elham Kariri, Turki Khawaji, Yasser Almubaddil and Sultan Aldwsary
Information 2024, 15(9), 516; https://doi.org/10.3390/info15090516 - 23 Aug 2024
Viewed by 723
Abstract
This work conducts a rigorous examination of the economic influence of tourism in Saudi Arabia, with a particular focus on predicting tourist spending patterns and classifying spending behaviors during the COVID-19 pandemic period and its implications for sustainable development. Utilizing authentic datasets obtained [...] Read more.
This work conducts a rigorous examination of the economic influence of tourism in Saudi Arabia, with a particular focus on predicting tourist spending patterns and classifying spending behaviors during the COVID-19 pandemic period and its implications for sustainable development. Utilizing authentic datasets obtained from the Saudi Tourism Authority for the years 2015 to 2021, the research employs a variety of machine learning (ML) algorithms, including Decision Trees, Random Forests, K-Neighbors Classifiers, Gaussian Naive Bayes, and Support Vector Classifiers, all meticulously fine-tuned to optimize model performance. Additionally, the ARIMA model is expertly adjusted to forecast the economic landscape of tourism from 2022 to 2030, providing a robust predictive framework for future trends. The research framework is comprehensive, encompassing diligent data collection and purification, exploratory data analysis (EDA), and extensive calibration of ML algorithms through hyperparameter tuning. This thorough process tailors the predictive models to the unique dynamics of Saudi Arabia’s tourism industry, resulting in robust forecasts and insights. The findings reveal the growth trajectory of the tourism sector, highlighted by nearly 965,073 thousand tourist visits and 7,335,538 thousand overnights, with an aggregate tourist expenditure of SAR 2,246,491 million. These figures, coupled with an average expenditure of SAR 89,443 per trip and SAR 9198 per night, form a solid statistical basis for the employed predictive models. Furthermore, this research expands on how ML and AI innovations contribute to sustainable tourism practices, addressing key aspects such as resource management, economic resilience, and environmental stewardship. By integrating predictive analytics and AI-driven operational efficiencies, the study provides strategic insights for future planning and decision-making, aiming to support stakeholders in developing resilient and sustainable strategies for the tourism sector. This approach not only enhances the capacity for navigating economic complexities in a post-pandemic context, but also reinforces Saudi Arabia’s position as a premier tourism destination, with a strong emphasis on sustainability leading into 2030 and beyond. Full article
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<p>Key tourism indicators in Saudi Arabia (dataset screenshot).</p>
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<p>Inbound tourist visits and expenditure by destination/provinces (dataset screenshot).</p>
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<p>Correlation matrix.</p>
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<p>Connections and interconnections between variables.</p>
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<p>Distribution of spending rates for each Inbound-region.</p>
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<p>Spending rates over time.</p>
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<p>Scatter plot for Decision Tree.</p>
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<p>Scatter plot for Random Forest.</p>
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<p>Scatter plot for K-Neighbors Classifier.</p>
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<p>Scatter plot for Gaussian Naive Bayes.</p>
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<p>Scatter plot for Support Vector Classification.</p>
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<p>Time series for predicting the rate of spending using the ARIMA algorithm. The blue series represents the actual spending data from 2016 to 2021, while the yellow series illustrates the predicted spending values from 2022 to 2026. This prediction highlights the anticipated trends and potential recovery in tourism expenditure following the impact of the COVID-19 pandemic. <span class="html-italic">Source: created by the authors using software.</span></p>
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<p>Comparison between classifiers. <span class="html-italic">Source: adapted from [<a href="#B17-information-15-00516" class="html-bibr">17</a>].</span></p>
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<p>Mean Absolute Error value of all classifiers. <span class="html-italic">Source: adapted from [<a href="#B11-information-15-00516" class="html-bibr">11</a>].</span></p>
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<p>Mean Squared Error value of all classifiers. <span class="html-italic">Source: adapted from [<a href="#B14-information-15-00516" class="html-bibr">14</a>].</span></p>
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<p>Median Squared Error value of all classifiers. <span class="html-italic">Source: adapted from [<a href="#B15-information-15-00516" class="html-bibr">15</a>].</span></p>
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14 pages, 2893 KiB  
Article
Evaluation of Hi-C Sequencing for Detection of Gene Fusions in Hematologic and Solid Tumor Pediatric Cancer Samples
by Anthony D. Schmitt, Kristin Sikkink, Atif A. Ahmed, Shadi Melnyk, Derek Reid, Logan Van Meter, Erin M. Guest, Lisa A. Lansdon, Tomi Pastinen, Irina Pushel, Byunggil Yoo and Midhat S. Farooqi
Cancers 2024, 16(17), 2936; https://doi.org/10.3390/cancers16172936 - 23 Aug 2024
Viewed by 537
Abstract
Hi-C sequencing is a DNA-based next-generation sequencing method that preserves the 3D genome conformation and has shown promise in detecting genomic rearrangements in translational research studies. To evaluate Hi-C as a potential clinical diagnostic platform, analytical concordance with routine laboratory testing was assessed [...] Read more.
Hi-C sequencing is a DNA-based next-generation sequencing method that preserves the 3D genome conformation and has shown promise in detecting genomic rearrangements in translational research studies. To evaluate Hi-C as a potential clinical diagnostic platform, analytical concordance with routine laboratory testing was assessed using primary pediatric leukemia and sarcoma specimens. Archived viable and non-viable frozen leukemic cells and formalin-fixed paraffin-embedded (FFPE) tumor specimens were analyzed. Pediatric acute myeloid leukemia (AML) and alveolar rhabdomyosarcoma (A-RMS) specimens with known genomic rearrangements were subjected to Hi-C to assess analytical concordance. Subsequently, a discovery cohort consisting of AML and acute lymphoblastic leukemia (ALL) cases without known genomic rearrangements based on prior clinical diagnostic testing was evaluated to determine whether Hi-C could detect rearrangements. Using a standard sequencing depth of 50 million raw read-pairs per sample, or approximately 5X raw genomic coverage, we observed 100% concordance between Hi-C and previous clinical cytogenetic and molecular testing. In the discovery cohort, a clinically relevant gene fusion was detected in 45% of leukemia cases (5/11). This study provides an institutional proof of principle evaluation of Hi-C sequencing to medical diagnostic testing as it identified several clinically relevant rearrangements, including those that were missed by current clinical testing workflows. Full article
(This article belongs to the Section Cancer Pathophysiology)
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<p>Genomic rearrangement detection using Arima Genomics’ Hi-C workflow. (Step 1) collect specimens and prepare for Hi-C testing. For hematologic cancers, extract the white blood cells from the bone marrow aspirates or peripheral blood and crosslink. For formalin-fixed paraffin-embedded (FFPE) solid tumors, de-wax and rehydrate the tissue; (Step 2) preserve the 3D conformation of the genome via Hi-C, resulting in labeled proximity ligated DNA that has preserved 3D conformation information; (Step 3) library preparation, resulting in a sequence-ready Hi-C library; (Step 4) next-generation sequencing (NGS); (Step 5) bioinformatics analysis using the Arima-SV v1.3 workflow to identify genomic rearrangements and visualize results.</p>
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<p>Hi-C is concordant with clinical cytogenetic testing for detecting clinically significant gene fusions. (<b>A</b>) Chromosome 6 × Chromosome 11 Hi-C heatmap from specimen “AML C6”. Genomic coordinates, gene locations, and sequencing coverage from Chromosome 6 and 11 are shown along the edges of the X and Y axes of the heatmap, respectively. Small black boxes overlaid on the heatmap are the Arima-SV pipeline genomic rearrangement calls. (<b>B</b>) Same as panel (<b>A</b>), except zoomed-in to the locus around the <span class="html-italic">KMT2A::MLLT4</span> gene fusion call. The <span class="html-italic">KMT2A</span> and <span class="html-italic">MLLT4</span> gene positions and orientations are indicated. Black dashed lines depict the breakpoint locations on each chromosome. (<b>C</b>) Chromosome 2 × Chromosome 13 Hi-C heatmap from specimen “ARMS C3”. Genomic coordinates, gene locations, and sequencing coverage from Chromosome 2 and 13 are shown along the edges of the X and Y axes of the heatmap, respectively. Small black boxes overlaid on the heatmap are the Arima-SV pipeline genomic rearrangement calls. (<b>D</b>) Same as panel (<b>C</b>), except zoomed-in to the locus around the <span class="html-italic">PAX3::FOXO1</span> gene fusion call. The <span class="html-italic">PAX3</span> and <span class="html-italic">FOXO1</span> gene positions and orientations are indicated. Black dashed lines depict the breakpoint locations on each chromosome. In all Hi-C heatmaps, pairs of loci with more Hi-C read support appear as darker red entries in the Hi-C heatmap, pairs of loci with less Hi-C read support appear as lighter red entries, and pairs of loci with no Hi-C support appear white/gray entries.</p>
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<p>Hi-C detects clinically significant gene fusions not previously detected by clinical cytogenetic and molecular testing. (<b>A</b>) Chromosome 6 × Chromosome 11 Hi-C heatmap from specimen “AML D1”. Genomic coordinates, gene locations, and sequencing coverage from Chromosome 6 and 11 are shown along the edges of the X and Y axes of the heatmap, respectively. Small black boxes overlaid on the heatmap are the Arima-SV pipeline genomic rearrangement calls. (<b>B</b>) Same as panel (<b>A</b>), except zoomed-in to the locus around the <span class="html-italic">KMT2A::MLLT10</span> gene fusion call. The <span class="html-italic">KMT2A</span> and <span class="html-italic">MLLT10</span> gene positions and orientations are indicated. Black dashed lines depict the breakpoint locations on each chromosome. (<b>C</b>) Chromosome 12 × Chromosome 22 Hi-C heatmap from specimen “B-ALL D8”. Genomic coordinates, gene locations, and sequencing coverage from Chromosome 12 and 22 are shown along the edges of the X and Y axes of the heatmap, respectively. Small black boxes overlaid on the heatmap are the Arima-SV pipeline genomic rearrangement calls. (<b>D</b>) Same as panel (<b>C</b>), except zoomed-in to the locus around the <span class="html-italic">ZNF384::EP300</span> gene fusion call. The <span class="html-italic">ZNF384</span> and <span class="html-italic">EP300</span> gene positions and orientations are indicated. Black dashed lines depict the breakpoint locations on each chromosome. (<b>E</b>) Same as panel (<b>C</b>), except from specimen “B-ALL D6”. (<b>F</b>) Same as panel (<b>D</b>), except from specimen “B-ALL D6”. In all Hi-C heatmaps, pairs of loci with more Hi-C read support appear as darker red entries in the Hi-C heatmap, pairs of loci with less Hi-C read support appear as lighter red entries, and pairs of loci with no Hi-C support appear white/gray entries.</p>
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