Prof. Awad Kh. Al-Asmari
Prince Sattam Bin Abdulaziz University, Electrica Engineering, Vice Rector Graduate Studies and Research
Prince Sattam Bin Abdulaziz University, Electrical Engineering, Vice Rector Graduate Studies and Research
Professor Awad Alasmari (Full Name Dr. Awad Khozam Sruoor Al Marad Al Asmari) was the rector of Shaqra University (SU), Saudi Arabia, He earned his bachelor's degree in electrical engineering from King Saud University (KSU), master’s degree from Ohio State University (OSU), Columbus, Ohio, USA, and PhD in Electrical Engineering from the University of Toledo (UT), Toledo, Ohio, USA.Alasmari has more than 36 years of experience in academia, holding different roles and responsibilities. Prior to joining the University, he was a member of the Shoura Council (a consultative assembly) of Saudi Arabia from 2013 to 2016. He also served at Prince Sattam bin Abdulaziz University as the vice rector for graduate studies and research and contributed immensely towards its development. He worked as a professor in Electrical Engineering Department at King Saud University and confidently contributed towards the development of the department to be promoted later as the dean of the College of Engineering at Al-Kharj (under the management of King Saud University).Alasmari played a major role in the development of Prince Sattam Bin Abdulaziz University as a vice rector for graduate studies and research. During his stint, he was successful in establishing an international co-operation between Prince Sattam Bin Abdulaziz University and University of California, Irvine, USA. This co-operation contributed positively towards the research of the University and also helped students acquire research skills at Irvine campus. He initiated a wide range of multidisciplinary research activities designed to cope with global and regional challenges. As the rector of Shaqra University, Alasmari always seeks to ensure improvement in students’ insights and skills. He prioritizes plans that support students’ learning experience. His inclination of excellence towards international scientific research is a springboard to encourage academic staff and students to engage in research activities and international cooperation with other universities around the globe. He is leading Shaqra University towards excellence in education and research, and positively transforming the campus that caters the latest needs of students, faculty members, staff, and administrators. He is highly committed to drive the University towards global excellence. Alasmari has received many prestigious awards from the government of Saudi Arabia such as honor shields from: His Royal Highness Prince Faisal bin Khaled bin Abdulaziz, His Royal Highness Prince Faisal bin Bander bin Abdulaziz, From KSU rector, From PSAU rector, and from the Deanship of Graduate Studies at KSU. He has numerous publications in IEEE and refereed international and national journals. For more information, please visit his website: www.alasmari.com
Phone: +966-11-647-9997
Address: Phone: +966-11-647-9997
alasmari@su.edu.sa, alasmari@ksu.edu.sa
PO Box (33) Postal Code (11961)
Shaqra,
Kingdom of Saudi Arabia
Phone: +966-11-647-9997
Address: Phone: +966-11-647-9997
alasmari@su.edu.sa, alasmari@ksu.edu.sa
PO Box (33) Postal Code (11961)
Shaqra,
Kingdom of Saudi Arabia
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compression with simple computational complexity is presented. This algorithm
performs the temporal decomposition of a video sequence in a more efficient way
by using 4-tap short symmetric kernel filter (Haar filters) with decimation factor
of 4:1 instead of 2:1 used in the classical 3D-wavelet algorithms. The pyramid
coding decomposition concept is then used for the spatial domain.
The main goal of this paper is to design a simple encoding algorithm with a
very high performance. Local adaptive vector quantization (LAVQ) is used to
encode some of the spatial subbands. The codebook of LAVQ is simple and
robust to the motion which occurs in the video sequences and which seldom
captures from a single training sequence. The other subbands are encoded using
the very simple coding algorithm called absolute moment block truncation code
(AMBTC). The AMBTC is used for the bands that are highly correlated and with
no motion or sparks information.
Experimental results demonstrate a significant improvement in performance
over earlier published algorithms. It gives an excellent image quality at PSNR on
the average of 36.9 dB and at a low bit rate of 0.13 bpp for Miss America
sequence. Finally, the coding and decoding of the proposed algorithm are of
comparable and relatively low complexity and is well suited to parallel
implementation.
scheme is adopted. The image is decomposed into two components. The first component is the primary
component, which contains the edges, the other component is the secondary component, which contains the
textures and the features. In this paper, a general grasp for the image is reconstructed in the first stage at a
bit rate of 0.0223 bpp for Sample (1) and 0.0245 bpp for Sample (2) image. The quality of the reconstructed
images is competitive to the 0.75 bpp target bit set by FBI standard. Also, the compression ratio and the image
quality of this algorithm is competitive to other existing methods given in the literature [6]-[9]. The
compression ratio for our algorithm is about 45:1 (0.180 bpp).
that is robust to fading errors in a spread spectrum environment. Schemes like subband
coding and pyramid coding are inherently well suited for SS-CDMA environment and thus,
pyramid coding is the chosen spatial decomposition scheme. Interframe coding using the
two tap short symmetric filters reduces the complexity of motion adaptation techniques used
in the MPEG standards.
compression with simple computational complexity is presented. This algorithm
performs the temporal decomposition of a video sequence in a more efficient way
by using 4-tap short symmetric kernel filter (Haar filters) with decimation factor
of 4:1 instead of 2:1 used in the classical 3D-wavelet algorithms. The pyramid
coding decomposition concept is then used for the spatial domain.
The main goal of this paper is to design a simple encoding algorithm with a
very high performance. Local adaptive vector quantization (LAVQ) is used to
encode some of the spatial subbands. The codebook of LAVQ is simple and
robust to the motion which occurs in the video sequences and which seldom
captures from a single training sequence. The other subbands are encoded using
the very simple coding algorithm called absolute moment block truncation code
(AMBTC). The AMBTC is used for the bands that are highly correlated and with
no motion or sparks information.
Experimental results demonstrate a significant improvement in performance
over earlier published algorithms. It gives an excellent image quality at PSNR on
the average of 36.9 dB and at a low bit rate of 0.13 bpp for Miss America
sequence. Finally, the coding and decoding of the proposed algorithm are of
comparable and relatively low complexity and is well suited to parallel
implementation.
scheme is adopted. The image is decomposed into two components. The first component is the primary
component, which contains the edges, the other component is the secondary component, which contains the
textures and the features. In this paper, a general grasp for the image is reconstructed in the first stage at a
bit rate of 0.0223 bpp for Sample (1) and 0.0245 bpp for Sample (2) image. The quality of the reconstructed
images is competitive to the 0.75 bpp target bit set by FBI standard. Also, the compression ratio and the image
quality of this algorithm is competitive to other existing methods given in the literature [6]-[9]. The
compression ratio for our algorithm is about 45:1 (0.180 bpp).
that is robust to fading errors in a spread spectrum environment. Schemes like subband
coding and pyramid coding are inherently well suited for SS-CDMA environment and thus,
pyramid coding is the chosen spatial decomposition scheme. Interframe coding using the
two tap short symmetric filters reduces the complexity of motion adaptation techniques used
in the MPEG standards.
The three phase current regulated pulse-width modulation (CRPWM) AC/DC/AC converters have been increasingly used for wind energy system applications. Their attractive features include: regulated DC-link voltage, low harmonic distortion of the induction generator currents and controllable power factor and efficiency in [8–9]. The current regulation of a SEIG in the synchronous frame has the advantages of fast dynamic current response, good accuracy, constant switching frequency and less sensitivity to parameter variations. In wind generation systems, a variable speed generation system is more attractive than a fixed speed one because of the improvement in the wind energy production. In a variable speed system, wind turbine can be operated to produce its maximum power at every wind speed by adjusting the shaft speed optimally. In order to achieve the maximum power point tracking (MPPT) control, some control schemes have been studied. For example, a search-based or perturbation-based strategy in [10–11], a fuzzy- logic based control in [12], a wind speed-estimation-based algorithm has been applied. Since the squirrel-cage IGs have robust construction, lower initial, run-time and maintenance cost, squirrel-cage IGs are suitable for grid-connected as well as isolated power sources in small hydroelectric and wind-energy applications. Therefore an IG system using radial basis function network (RBFN) was proposed to yield maximum power output through the DC-link power control in [13-14].
In the past several years, much research has been carried out in neural network control. It has proven that an artificial neural network can approximate a wide range of nonlinear functions to any desired degree of accuracy under certain conditions. In the conventional gradient descent method of weight adaptation, the sensitivity of the controlled system is required in the on-line training process. However, it is difficult to acquire sensitivity information for unknown or highly non-linear dynamics. Wavelets have been combined with the neural network to create wavelet–neural–networks (WNNs). It combine the capability of artificial neural networks for learning from process and the capability of wavelet decomposition for identification and control of dynamic systems. The training algorithms for WNN typically converge in a smaller number of iterations than the conventional neural networks. Unlike the sigmoid functions used in the conventional neural networks, the second layer of WNN is a wavelet form, in which the translation and dilation parameters are included. Thus, WNN has been proved to be better than the other neural networks in that the structure can provide more potential to enrich the mapping relationship between inputs and outputs in [15-23].
Particle swarm optimization (PSO), first introduced by Kennedy and Eberhart in [24], is one of the modern heuristic algorithm. It was developed through simulation of a simplified social system and has been found to be robust in solving continuous nonlinear optimization problem in [25-29]. The PSO technique can generate a high quality solution within shorter calculation time and stable convergence characteristics than other stochastic methods in [30-34]. Much research is still in progress for proving the potential of the PSO in solving complex dynamical systems.
The recent evolution of power-electronics technologies has aided the advancement of variable-speed wind-turbine generation systems in [35–39]. In spite of the additional cost of power electronics and control circuits, the total energy captured in a variable-speed wind-turbine system is more than the conventional one. Thus, the variable-speed wind-turbine system has lower life-cycle cost. Moreover, the PWM converters not only can be used as a variable capacitor but also can supply the needed reactive power to load and to minimize the harmonic current and imbalance in the generator current. On the other hand, the variable speed wind turbine driven SEIG systems display highly resonant, nonlinear, and time-varying dynamics subject to wind turbulence and operating temperature of the SEIG. Furthermore, there is an appreciable amount of fluctuation in the magnitude and frequency of the generator terminal voltage owing to a varying rotor speed governed by the wind velocity and the pulsating input torque from the wind turbine. The phenomena of fluctuation are objectionable to some sensitive loads. Therefore, the employment of PWM converters with advanced control methodologies to control the wind turbine driven SEIG systems is necessary in [36–38]. In addition, for the research of wind energy conversion systems, the developments of wind turbine emulators are also necessary in [43, 44]. However, the fuzzy logic controller, the sliding-mode controller, and the PI controller adopted in [40–48] may not guarantee the robustness when parameter variations or external disturbance occurred in the control system in practical applications due to the lack of online learning ability.
This Chapter is organized as follows. Section 2 presents the variable speed wind generation system description. In this section the analysis of the wind turbine is carried out and the maximum power point tracking analysis is also introduced. In Section 3, the dynamic model of the self-excited induction generator is introduced to analyze all its characteristics. Section 4 provides the indirect field-orientation control (IFOC) dynamics for the IG (torque, slip angular frequency and voltage commands) which are derived from the dynamic model of SEIG. The d-q axes current control according to the IG rotor speed gives the maximum mechanical power from the wind turbine and the losses of the IG are minimized. In Section 5, the dynamic equations of the CRPWM converter in the synchronous reference frame are carried out based on the IFOC dynamics of the IG. The dynamic equations of the grid-side CRPWM voltage source inverter connected to the grid are given in Section 6. By using vector control technique, the currents of the CRPWM inverter are controlled with very high bandwidth. The vector control approach is used, with a reference frame oriented along the grid voltage vector position. This allows independent control of the active and reactive power. Section 7 considers the design procedures for the PID voltage controller of the IG-side CRPWM voltage source converter, the PID active power and reactive power controllers for the grid-side CRPWM inverter. In Section 8, an intelligent maximization hybrid control system based on the WNN with IPSO is proposed in order to control the DC-link voltage of the IG-side CRPWM voltage source converter, active power and reactive power of the grid-side CRPWM voltage source inverter effectively based on the MPPT from the wind driven SEIG system. Finally, to testify the design of the proposed hybrid control system and MPPT control scheme, the variable speed wind generation system is simulated in Section 9. The dynamic performance of the system has been studied under different wind velocities. The simulation results are provided to demonstrate the effectiveness of the proposed hybrid control for variable speed wind generation system.
Another transform technique that is used extensively in image coding is the pyramid transform which was first introduced by Burt and Adelson [12]. It can provide high compression rates and at the same time low complexity encoding. Like the DWT, pyramid transform provides multi-resolution representation of the images. These properties can be used in watermarking to establish a robust data hiding system.
In this chapter, our target is to develop an algorithm using optimal pyramid decomposition technique, and combine it with wavelet decompositions. The algorithm will be used for data hiding in digital images to meet the requirements of imperceptibility, robustness, storage requirements, security, and complexity.
A typical image, for example, of size 512x512 pixels with 8 bits per pixel (bpp) needs storage capacity of about 2 Mbits. A video sequence, on the other hand, with the same frame size with 30 frames per second and a channel transmission rate of 64 kilo bits per second (kbps) would take about 17 minutes of transmission time. The required transmission time would become unmanageable with the continuously increasing demand of image base application. You can't put enough of it over a telephone line and you can't squeeze it into the broadcast bandwidth of available channels[1] -2 Hybrid coding of images for progressive transmission over a digital cellular channel, CISST’99 International Conference on Imaging Science, Systems and Technology, Monte Carlo resort, Las Vegas, Nevada, USA, PIN 128C (Al-Asmari et al.,June 28 – July 1, 1999).. Therefore, image and video compression algorithms became a necessity to store or transmit these images.
Data compression is the science of representing information in a compact form by exploiting the different kinds of statistical structures that may be present in the data[1] -. This is to reduce the number of bits per sample while keeping the distortion constant3. There is a great deal of correlation between neighboring pixel values of an image. Therefore, removing such redundant information and transmitting only the new information (the changes) enables us to reconstruct the original image. For video signals, redundancy over time between successive images can also be eliminated.
There are two types of compression: lossless and lossy. In the lossless compression the original image can be retrieved without error, while for the lossy compression, the original image can’t be retrieved without error; an image copy close to the original can be retrieved.
Motion pictures expert group (MPEG) video standard is the most prevalent and widely used for video compression[1] -5 Image and video compression standards: algorithms and architectures, Kluwer Academic Publishers (Bhaskaran & Konstantinidides & Hewlett Packard Laboratories, 1996).6 Digital compression of still images and video, Academic Press (Clarke, 1995).7 Subband coding of video for packet networks, Optical Engineering, vol. 27, no. 7, pp. 574-586, (Karlsson & Vetterli, July 1988).8 Pyramid coding of video signals for progressive transmission, CISST’97 International Conference, pp-392-398, (Dantwala et al., June 30 – July 3, 1997). 6. Also, the MPEG is an application specific standard and different versions of MPEG (Such as MPEG-1, MPEG-2, MPEG-4, and MPEG-7) are available for different applications and bit rates. The basic algorithm for all these versions is the same and is very similar to the other video compression standards.
The proposed algorithm is based on temporal filtering of image sequences with short symmetric kernel filters (SSKFs)7–8, which are well known for their simplicity. In this paper, we use four SSKFs filters each with 4-taps and with decimation factor of 4:1 instead of two SSKFs filters each of 2-taps and with decimation factor of 2:1 used in classical 3D – decomposition algorithms7–8. The temporal filtering removes the redundancy in temporal domain. On the other hand, the pyramid coding (PC) is used for subband decomposition in the spatial domain. The vector quantization (VQ) and the absolute moment block truncation code (AMBTC) will be used to encode the spatial domain subbands.
area; this characterization showed a different behavior for the
nano sized fibers such as super absorbent characteristics for
electrospun PAM nano fibers [1] and nano reinforcement size
effect with carbon nano tubes [2] and graphite nano platelet
[3] which has been correlated to the unusual behavior of
molecular chains on the surface of nano scale fibers. It’s well
known that, atoms at a free surface experience a different
local environment than do atoms in the bulk of a material; as a
result, the energy associated with these atoms will, in general,
be different from that of the atoms in the bulk. The excess
energy associated with surface atoms is called surface free
energy. In traditional continuum mechanics, such surface free
energy is typically neglected because it is associated with
only a few layers of atoms near the surface and the ratio of the
volume occupied by the surface atoms and the total volume of
material of interest is extremely small. However, for nanosize materials such as nano fibers, the surface to volume ratio
becomes significant, and so does the effect of surface free
energy. The effect of surface energy on the elastic behavior at
the nano level has been studied in the literature. For example
Dingreville and et al [4] showed 20% increase in the axial
Young’s modulus for 4 nm diameter copper wire. Also,
Nanda et al [5] showed 5-6 times increase in material surface
energy for Ag nano-particles relative to bulk.
Also, He and et al [6] found a size effect in the elastic
property of electrospun PAN nanofibers below 150 nm.
Also, nano diamond nucleation has been reported for carbon
nanomaterials below the required pressure and temperature
for similar bulk materials [7&8].
The present study is an attempt to continue a work that has
been started by Ali AA and Rutledge GC [9] to use this high
surface energy of the electrospun PAN nano fibers along with
different carbon nano tube sizes as a cohesive bond to build a
firm strong precursor carbon nano fibril composite fabrics.
Also, to get the use of the high degree of entanglement inside
the nano fibrous structure and carbon nano tubes to gain a
higher degree of flexibility in the overall produced fabrics.
Finally a heat treatment in nitrogen has been took place to
improve the conductivity and to produce CNT/carbon nano
fibril composite fabrics that can be used in many applications.
and transmission using edge detection scheme is adopted.
The image is decomposed into two (primary and
secondary) components. Canny method is adopted to
detect the edges of the encoded image. These edges are
replaced with a pre-designed nine basis nameplates. Then,
the Macro edge detection technique is used to reduce the
number of these nameplates and keep only the edges that
are necessary for visual quality.
Eight directional predictions and interpolation
technique will be performed on the encoded edges to
reconstruct the first layer of the primary component at
both receiver and transmitter sides. This is called the 1st
stage reconstructed image, which is subtracted from the
original to have the 1st stage smooth component. Then,
this process will be repeated for the 2nd and the 3rd stage
components.
The 3rd stage smooth component is filtered using
an optimal decomposition filter and then decimated by a
factor of 2. The decimated component is encoded using
VQ. The decoded result of the smooth image is added to
the three layers that form the primary component to have
the reconstructed image. An excellent reconstructed
images are found at an average of 0.179 bpp (compression
ratio 45:1) and with an average PSNR of 39.45 dB. This
algorithm is found to be of lower bit rate than existing
image compression techniques.
scheme that employs human visual sensitivity (HVS)
to hide a large amount of secret bits into a still
image with a high imperceptibility. In this method,
the cover image is divided into sub-blocks of semihexagonal shape. The embedding technique is
based on pixel value difference (PVD) approach.
The semi-hexagonal (SH-PVD) technique enjoys
better objective and subjective qualities over the
standard PVD methods.
It has been found that the capacity of the
proposed algorithm is higher than that of the most
recent published algorithms. The simulation results
give an increased in the capacity ranged between
10348 to 366637 bits. The visual quality of the
cover images is of excellent quality. The new
algorithm adds no complexity to the existing PVD
methods.
discrete wavelet transform (DWT) has been used extensively in recent years in watermarking systems. It provides the
necessary perceptual invisibility and robustness. In this paper, a pre-DWT process is implemented using optimal pyramid
transform (OPT), where one of the error images that are resulted from the pyramid transform is decomposed using DWT,
and a watermark is inserted in one of its subbands. Then, the watermarked image is reconstructed. The filters used for OPT
and DWT decompositions are randomly generated to increase the security of this algorithm.
The simulation results show that the proposed algorithm achieves a saving of 54% in the computational complexity.
When the median filter attack is used, the correlation will be on the average of 47.9% higher than earlier published
algorithms.
Index Terms- , , , .
compression with simple computational complexity is presented. This algorithm
performs the temporal decomposition of a video sequence in a more efficient way
by using 4-tap short symmetric kernel filter (Haar filters) with decimation factor
of 4:1 instead of 2:1 used in the classical 3D-wavelet algorithms. The pyramid
coding decomposition concept is then used for the spatial domain.
The main goal of this paper is to design a simple encoding algorithm with a
very high performance. Local adaptive vector quantization (LAVQ) is used to
encode some of the spatial subbands. The codebook of LAVQ is simple and
robust to the motion which occurs in the video sequences and which seldom
captures from a single training sequence. The other subbands are encoded using
the very simple coding algorithm called absolute moment block truncation code
(AMBTC). The AMBTC is used for the bands that are highly correlated and with
no motion or sparks information.
Experimental results demonstrate a significant improvement in performance
over earlier published algorithms. It gives an excellent image quality at PSNR on
the average of 36.9 dB and at a low bit rate of 0.13 bpp for Miss America
sequence. Finally, the coding and decoding of the proposed algorithm are of
comparable and relatively low complexity and is well suited to parallel
implementation.
compression called semi-hexagonal absolute moment
block truncation coding (SH-AMBTC) is proposed. It
enjoys better objective and subjective qualities over the
standard square shaped AMBTC. This technique based on
the prediction of the bit-map of the middle frames in a
sequence from the bit-map of the end frames (the first and
the last frames in the group). The new algorithm adds no
complexity to the existing standard.
The proposed algorithm achieves a lower MSE than the
AMBTC as well as reduces the blocking effect. The
simulation results show that this significant improvement
in the visual quality is achieved at an average MSE of
(45.5), which is lower than that of AMBTC (48.4). On the
average the MSE can be reduced by 6% less than that of
AMBTC at the same bit rate.