Ibb, Yemen
Ibb, Yemen

Ibb University, was established in Ibb as an official University in 1996. It was founded by Nasser al-Awlaki.The university consists of 8 colleges as follows. Education College in Ibb Education College in Al Nadira Faculty of Commerce and Administrative science Faculty of Arts Faculty of science Faculty of Dentists Faculty of Engineering and Architecture Faculty of Agriculture and Veterinary Medicine↑ Wikipedia.

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Al-Rawi M.F.A.-H.,Ibb University | Al-Rawi M.F.A.-H.,University of Mustansiryia
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

This paper deals with the performance of standard 32 kb/s ADPCM. This performance is measured using signal-tonoise ratio (SNR). Here, the new contribution is related with mathematical derivation of SNR for asynchronous tandem ADPCM systems as given in section 5. Another contribution is study this performance using QAM modem signal with different constellations. A computer simulation program has been developed and a number of simulation tests have been carried out using QAM modem signal at 9.6 Kb/s with four types of constellations, rectangular, and (5,11), (4,12), (8,8) circular. The results of testing asynchronous tandem ADPCM systems show that the performance degrades with increasing the stages of ADPCM. Also, the results show that the performance with circular constellation is better than rectangular constellation. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Alwany A.E.B.,Ibb University
Optics and Laser Technology | Year: 2012

Thin films of Zn 40Se 60 were prepared by the vacuum thermal evaporation technique. The influence of annealed temperature on the structural and optical properties was investigated using the X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical transmission. The XRD studies show that the as-deposited film is amorphous in nature, but the crystallinity improved with increasing the annealing temperature. Furthermore the particle size and crystallinity increased whereas the dislocation and strains decreased with increasing the annealing temperature. SEM studies showed that the annealing temperature induced changes in the morphology of the as-deposited sample. Various optical constant have been calculated for as-deposited and annealed films. The mechanism of the optical absorption follows the rule of direct transition. It was found that, the optical energy gap (E g) decreased with increasing the annealing temperature. These results can be interpreted by the Davis and Motte model. On the other hand the maximum value of the refractive index (n) is shifted toward the long wavelength by increasing the annealing temperature. © 2011 Elsevier Ltd. All rights reserved.

Goliaei S.,Modares University | Foroughmand-Araabi M.-H.,Ibb University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2012

The optical wavelength-based machine, or simply w-machine, is a computational model designed based on physical properties of light. The machine deals with sets of binary numbers, and performs computation using four defined basic operations. The sets are implemented as light rays and wavelengths are considered as binary numbers. Basic operations are then implemented using simple optical devices. In this paper, we have provided a polynomial lower bound on the complexity of any w-machine computing all satisfiable SAT formulas. We have shown that the provided lower bound is tight by providing such a w-machine. Although the size complexity of the SAT problem on w-machine is polynomial, but, according to the provided optical implementation, it requires exponential amount of energy to be computed. We have also provided an exponential lower bound on the complexity of most of w-machine languages, by showing that when n tends to infinity, the ratio of n-bit languages requiring exponential size w-machine to be computed, to the number of all n-bit languages, converges to 1. © 2012 Springer-Verlag.

Al-Shamri M.Y.H.,Ibb University | Al-Shamri M.Y.H.,King Khalid University
Expert Systems with Applications | Year: 2014

E-commerce systems employ recommender systems to enhance the customer loyalty and hence increasing the cross-selling of products. However, choosing appropriate similarity measure is a key to the recommender system success. Based on this measure, a set of neighbors for the current active user is formed which in turn will be used later to recommend unseen items to this active user. Pearson correlation coefficient, the most popular similarity measure for memory-based collaborative recommender system (CRS), measures how much two users are correlated. However, statistic's literature introduced many other coefficients for matching two sets (vectors) that may perform better than Pearson correlation coefficient. This paper explores Jaccard and Dice coefficients for matching users of CRS. A more general coefficient called a Power coefficient is proposed in this paper which represents a family of coefficients. Specifically, Power coefficient gives many degrees for emphasizing on the positive matches between users. However, CRS users have positive and negative matches and therefore these coefficients have to be modified to take negative matches into consideration. Consequently, they become more suitable for CRS research. Many experiments are carried out for all the proposed variants and are compared with the traditional approaches. The experimental results show that the proposed variants outperform Pearson correlation coefficient and cosine similarity measure as they are the most common approaches for memory-based CRS. © 2014 Elsevier Ltd. All rights reserved.

Dosunmu R.,University of Rhode Island | Alashwal H.,University of Rhode Island | Alashwal H.,Ibb University | Zawia N.H.,University of Rhode Island
Mechanisms of Ageing and Development | Year: 2012

In this study, we assessed global gene expression patterns in adolescent mice exposed to lead (Pb) as infants and their aged siblings to identify reprogrammed genes. Global expression on postnatal day 20 and 700 was analyzed and genes that were down- and up-regulated (≥2 fold) were identified, clustered and analyzed for their relationship to DNA methylation. About 150 genes were differentially expressed in old age. In normal aging, we observed an up-regulation of genes related to the immune response, metal-binding, metabolism and transcription/transduction coupling. Prior exposure to Pb revealed a repression in these genes suggesting that disturbances in developmental stages of the brain compromise the ability to defend against age-related stressors, thus promoting the neurodegenerative process. Overexpression and repression of genes corresponded with their DNA methylation profile. © 2012.

Alqudami A.,Ibb University
Environmental science and pollution research international | Year: 2011

This work aimed at investigating the adsorption of lead and cadmium onto Fe and Ag nanoparticles for use as a water contaminant removal agent as a function of particle type, sorbent concentration, and contact time. Fe and Ag spherical nanoparticles were prepared in water by the lab-made electro-exploding wire (EEW) system and were investigated for their structure properties. Adsorption experiments were carried out at room temperature and pH 8.3 water solutions. The removal/adsorption of both Pb(II) and Cd(II) ions was found to be dependent on adsorbent dosage and contact time. Pb(II) adsorption onto Fe and Ag nanoparticles showed more or less similar efficiency and behavior. The kinetic data for the adsorption process obeyed pseudo second-order rate equations. The calculated equilibrium adsorption capacities (q(e)) were 813 and 800 mg/g for Pb sorption onto Fe and Ag nanoparticles, respectively. Cd(II) ion adsorption onto Fe nanoparticles obeyed pseudo second-order rate equations with q(e) equal to 242 mg/g, while their adsorption onto Ag nanoparticles obeyed pseudo first-order rate equations with q(e) of 794 mg/g. The calculated q(e)s are in quite agreement with the experimental values. The removal/uptake mechanisms of metal ions involved interaction between the metal ion and the oxide/hydroxyl layer around the spherical metallic core of the nanoparticle in water medium. Fe and Ag nanoparticles prepared using the EEW technique exhibited high potentials for the removal of metal ions from water with very high adsorption capacities, suggesting that the EEW technique can be enlarged to generate nanoparticles with large quantities for field or site water purification.

Panjkovich A.,Ibb University | Daura X.,Ibb University | Daura X.,Catalan Institution for Research and Advanced Studies
BMC Structural Biology | Year: 2010

Background. With the classical, active-site oriented drug-development approach reaching its limits, protein ligand-binding sites in general and allosteric sites in particular are increasingly attracting the interest of medicinal chemists in the search for new types of targets and strategies to drug development. Given that allostery represents one of the most common and powerful means to regulate protein function, the traditional drug discovery approach of targeting active sites can be extended by targeting allosteric or regulatory protein pockets that may allow the discovery of not only novel drug-like inhibitors, but activators as well. The wealth of available protein structural data can be exploited to further increase our understanding of allosterism, which in turn may have therapeutic applications. A first step in this direction is to identify and characterize putative effector sites that may be present in already available structural data. Results. We performed a large-scale study of protein cavities as potential allosteric and functional sites, by integrating publicly available information on protein sequences, structures and active sites for more than a thousand protein families. By identifying common pockets across different structures of the same protein family we developed a method to measure the pocket's structural conservation. The method was first parameterized using known active sites. We characterized the predicted pockets in terms of sequence and structural conservation, backbone flexibility and electrostatic potential. Although these different measures do not tend to correlate, their combination is useful in selecting functional and regulatory sites, as a detailed analysis of a handful of protein families shows. We finally estimated the numbers of potential allosteric or regulatory pockets that may be present in the data set, finding that pockets with putative functional and effector characteristics are widespread across protein families. Conclusions. Our results show that structurally conserved pockets are a common feature of protein families. The structural conservation of protein pockets, combined with other characteristics, can be exploited in drug discovery procedures, in particular for the selection of the most appropriate target protein and pocket for the design of drugs against entire protein families or subfamilies (e.g. for the development of broad-spectrum antimicrobials) or against a specific protein (e.g. in attempting to reduce side effects). © 2010 Panjkovich and Daura; licensee BioMed Central Ltd.

Since the conventional zero-forcing receiver does not operate satisfactorily in interference-limited environments, because of its noise amplification; the statistics of the transmitted data and the additive noise are required for the minimummean-square error receiver; the potential of the regularised receiver is proposed and investigated in this study to cope with these problems. In this study, the authors introduce an efficient low-complexity joint regularised equalisation and carrier frequency offset compensation (LJREC) scheme for single-carrier frequency division multiple access system. The proposed LJREC scheme avoids the noise amplification problem and the estimation of the signal-to-noise ratio and the interference matrices of other users. From the obtained simulation results, the proposed scheme enhances the system performance with lower complexity and sufficient robustness to the estimation errors. © The Institution of Engineering and Technology 2014.

Physical layer security is considered as a promising technique that exploits the channel properties in order to send confidential messages to the legitimate receiver even in the presence of a powerful eavesdropper and the absence of its channel information. In this study, the authors consider the effect of massive multiple-input and multiple-output (MMIMO) system operating in TDD mode in improving the physical layer security in the presence of multi-antennas eavesdropper. The channel state information (CSI) of the eavesdropper is assumed not known at the transmitter side, and also imperfect CSI of the legitimate receiver is assumed. The first important finding is that MMIMO is a valuable technique to combat passive eavesdropping, where it is shown that the achievable secrecy rate increases logarithmically with the number of transmit antennas. However, the eavesdropper can be active and attack the training phase of the legitimate transmitter. As a consequence, this dramatically reduces the achievable secrecy rate. The second contribution of this study is a simple protocol that can effectively detect this attack so that a countermeasure can be taken. Closed-form expressions for the detection and false-alarm probabilities are derived. Moreover, the authors analyse the intercept probability and show that asymptotically exponential diversity is achieved. © The Institution of Engineering and Technology.

Soliman M.I.,Aswan University | Al-Junaid A.F.,Ibb University
Journal of Parallel and Distributed Computing | Year: 2013

This paper proposes extending a multi-core processor with a common matrix unit to maximize onchip resource utilization and to leverage the advantages of the current multi-core revolution to improve the performance of data-parallel applications. Each core fetches scalar/vector/matrix instructions from its instruction cache. Scalar instructions continue the execution on the scalar datapath; however, vector/matrix instructions are issued by the decode stage to the shared matrix unit through the corresponding FIFO queue. Moreover, scalar results from reduction vector/matrix instructions are sent back from the matrix unit to the scalar core that sent these instructions. Some dense linear algebra kernels (scalar-vector multiplication, scalar times vector plus another, apply Givens rotation, rank-1 update, vector-matrix multiplication, and matrix-matrix multiplication) as well as discrete cosine transform, sum of absolute differences, and affine transformation are used in the performance evaluation. Our results show that the improvement in the utilization of the shared matrix unit with a dual-core ranges from 9% to 26% compared to extending a matrix unit to a single-core. Moreover, the average speedup of the dualcore shared matrix unit over a single-core extended with a matrix unit ranges from 6% to 24% and the maximum speedup ranges from 13% to 46%. © 2013 Elsevier Inc.

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