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Search Results: 1 - 10 of 895 matches for " Yasser Ammar "
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Non Linear Techniques for Increasing Harvesting Energy from Piezoelectric and Electromagnetic Micro-Power-Generators
Yasser Ammar,S. Basrour
Computer Science , 2007,
Abstract: Non-linear techniques are used to optimize the harvested energy from piezoelectric and electromagnetic generators. This paper introduces an analytical study for the voltage amplification obtained from these techniques. The analytical study is experimentally validated using a macro model of piezoelectric generator. Moreover, the integration influences on these techniques is studied. Through all the obtained results, a suitable structure for autonomous microsystems is proposed.
Template Matching from 2-D into 1-D  [PDF]
Yasser Fouda
Journal of Signal and Information Processing (JSIP) , 2014, DOI: 10.4236/jsip.2014.52005
Abstract: The following article has been retracted due to special reason of the authors. This paper published in Vol.5
No. 2, 2014, has been removed from this site.

Title: Template Matching from 2-D into 1-D

Author: Yasser Fouda

Reverse-Osmosis Desalination of Water Powered by Photo-Voltaic Modules  [PDF]
Ammar Alkhatib
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2014, DOI: 10.4236/cweee.2014.31003

The rising of the world’s population leads automatically to the rising of water demand. As a consequence the lack of drinking water increases. Currently, approximately 1.2 billion people globally (one-sixth of the world’s population) do not have access to adequate clean water. Since a large part of the world’s population is concentrated in coastal areas, the desalination of seawater seems to be a promising solution, especially in our Arab world. An innovative stand-alone solar desalination system could be used to produce drinking water from seawater or any brackish water sources. The great advantage of such a system is that it combines efficient desalination technology, reverse osmosis, with a renewable energy source; the main goal is improving the technical feasibility of such systems. There are many advantages of this coupling with RE resources; first of all we separate the drinking water from the electricity grid and its faults, save the burning fossil fuel and its emissions and can provide fresh water to remote communities that do not have sufficient traditional energy sources; but as we see in the thesis we don’t have economic benefit; because these projects depend on the electricity cost in each country and its location and its solar specifications. We design and implement a small laboratorial model for PV-RO (Photo-Voltaic Powered Reverse Osmosis) to recognize the its performance for seawater and brackish

A Decision Tree Classifier for Intrusion Detection Priority Tagging  [PDF]
Adel Ammar
Journal of Computer and Communications (JCC) , 2015, DOI: 10.4236/jcc.2015.34006
Abstract: Snort rule-checking is one of the most popular forms of Network Intrusion Detection Systems (NIDS). In this article, we show that Snort priorities of true positive traffic (real attacks) can be approximated in real-time, in the context of high speed networks, by a decision tree classifier, using the information of only three easily extracted features (protocol, source port, and destination port), with an accuracy of 99%. Snort issues alert priorities based on its own default set of attack classes (34 classes) that are used by the default set of rules it provides. But the decision tree model is able to predict the priorities without using this default classification. The obtained tagger can provide a useful complement to an anomaly detection intrusion detection system.
Comparison of Feature Reduction Techniques for the Binominal Classification of Network Traffic  [PDF]
Adel Ammar
Journal of Data Analysis and Information Processing (JDAIP) , 2015, DOI: 10.4236/jdaip.2015.32002
Abstract: This paper tests various scenarios of feature selection and feature reduction, with the objective of building a real-time anomaly-based intrusion detection system. These scenarios are evaluated on the realistic Kyoto 2006+ dataset. The influence of reducing the number of features on the classification performance and the execution time is measured for each scenario. The so-called HVS feature selection technique detailed in this paper reveals many advantages in terms of consistency, classification performance and execution time.
Modified technique for volumetric brain tumor measurements  [PDF]
Yasser M. Salman
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.21003
Abstract: Quantitative measurements of tumor response rate in three dimensions (3D) become more re-alistic with the use of advanced technology im-aging during therapy, especially when the tumor morphological changes remain subtle, irregular and difficult to assess by clinical examination. These quantitative measurements depend strongly on the accuracy of the segmentations methods used. Improvements on such methods yield to increase the accuracy of the segmentation process. Recently, the essential modification in the Traditional Region Growing (T-RG) method has been developed and a “Modified Region Growing Method” (MRGM) has been presented and gives more accurate boundary detection and holes filling after segmentation. In this pa-per, the new automatic calculation of the volu-metric size of brain tumor has been imple-mented based on Modified Region Growing Method. A comparative study and statistical analysis performed in this work show that the modified method gives more accurate and better performance for 3D volume measurements. The method was tested by 7 fully investigated pa-tients of different tumor type and shape, and better accurate results were reported using MRGM.
Effect of Local and Global Scour on Lateral Response of Single Piles in Different Soil Conditions  [PDF]
Yasser E. Mostafa
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.46039
Abstract: Marine structures, offshore platforms and bridge piers are usually supported on foundation piles. These piles are subjected to lateral loading due to wind, waves and currents. Piles installed in marine or river environments are susceptible to scour depending on wave and current characteristics and soil types. In this paper, the effect of local and global scour on behavior of laterally loaded piles installed in different soil conditions has been investigated. Finite element model (FEM) using the software program PLAXIS and Winkler model using the software program LPILE were used in the analyses. Different parameters were investigated such as soil types, scour depth, scour hole dimension, pile material, submerged condition, magnitude of lateral load and load eccentricity. The results showed that scour has a significant impact on piles installed in sand and a less significant impact on piles installed in clay. Global scour has a significant impact on pile lateral displacement and bending stresses. The effect of scour is more significant if piles are subjected to large lateral loads due to the nonlinear response of pile-soil system. Effect of scour of stiff clayey soils on piles is more pronounced than that of soft clayey soils.
Affects of Female Directors on Firms Performance in Pakistan  [PDF]
Qaiser Rafique Yasser
Modern Economy (ME) , 2012, DOI: 10.4236/me.2012.37104
Abstract: This study examined relationship between board gender diversity and its effect on firm performance, based on evidence from the Pakistan. We use empirical data on KSE 100 Index firms observed in 2008 to 2010. Twenty Five percent (25%) of the sample firms have at least one woman in the boardroom and only 3.33% of the CEOs are female. In order to investigate the rapport of gender diversity in board on firm performance, two-stage least-squares estimation used, using Economic Valued Added (EVA) as performance measurement technique. Our results indicate that there is no significant relationship between board gender diversity on firm performance in Pakistan. This implies that the business case for board gender diversity is not supported for this particular sample.
Method for Improving the Lateral Resolution of Near-Infrared (NIR) Single Optods: Application to Subcutaneous Vein Detection and Localization  [PDF]
Yasser S. Fawzy
Optics and Photonics Journal (OPJ) , 2012, DOI: 10.4236/opj.2012.24044

NIR backscattering measurements using single source-detector optical probe (optods) can detect absorption areas within deep tissue layer. However, such optods, are characterized by large separation distance between the source and detectors (>2 cm) and poor lateral resolution (>1 cm), which limits its usage for the localization of small absorption volumes embedded deep within the tissue such as subcutaneous veins. In this work a method to improve the accuracy of locating such absorption volumes (areas) using backscattered NIR measurements is suggested and investigated with the aim of developing an optical sensor for detecting and localizing large subcutaneous veins. The method is based on measuring the differential signal from three overlapping source-detector pairs arranged within the probe such that the total photon sensitivity profile of the probe is maximized along a narrow width area (within the central of the probe) and minimized along its sides. The location of the absorption areas is then determined when a peak maximum of the measured signal is detected. Monte Carlo simulation and light transport modeling was used to determine the optimum arrangement of each source-detector pair within the probe to create the required spatial sensitivity profile and demonstrate the validity of the method. The results showed that the differential optode has more than two times improvement in the lateral resolution compared to the standard optode. The result also showed that the differential probe can locate subcutaneous veins with diameter ~5 mm and embedded at ~1.5 cm depth. The method could have a potential for designing and developing an optical backscattering sensors for detecting and localizing large subcutaneous veins embedded <2 cm depths

Design Considerations for Pile Groups Supporting Marine Structures with Respect to Scour  [PDF]
Yasser E. Mostafa
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.412106
Abstract: Piles supporting marine structures such as jetties, relieving platforms, quay walls and fixed offshore structures are subjected to lateral loads due to berthing and mooring forces, wind, waves, storm surges and current forces. This paper presents some factors that affect the design of pile groups supporting marine structures founded in cohesionless soils. Some main aspects that should be considered in the pile group design are addressed such as pile batter angle, pile group arrangement, pile spacing, pile slenderness ratio and magnitude of lateral static loading. Numerical analyses were conducted to investigate these design aspects with and without impact of scour. Different scour depths were considered to cover the possible root causes of scour around pile groups such as waves, current and ship propeller jets. The study revealed that scour has greater impact on lateral loading of pile groups compared to its impact on single piles. Pile groups with side-by-side arrangement exposed to scour are more critical than single piles and piles groups with tandem arrangement due to the combined effect of scour and pile-soil-pile interaction. It is also concluded that scour protection is not always required. More attention and considerations should be given to scour protection around piles especially if the piles are closely spaced, arranged side-by-side and if slenderness ratio is less than 12.5.
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