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Search Results: 1 - 10 of 297862 matches for " Ammar J "
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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.
The Energy Regeneration of Electromagnetic Energy Saving Active Suspension in Full Vehicle with Neurofuzzy Controller
Ammar A. Aldair,Weiji J. Wang
International Journal of Artificial Intelligence & Applications , 2011,
Abstract: To improve the vehicle performance such as ride comfort and road handling, the active suspensionsystem should be used. However, the current active suspension system has a high energy consumptiontherefore reducing the fuel economy. In this paper the vibration excited by road unevenness is treated asa source of mechanical energy. It is being converted into electrical energy to compensate for the energyconsumption by the active suspension. To achieve this task, an electromagnetic active suspension systemhas been introduced. The power generated from this device has been used as input power of the pump ofthe hydraulic actuators. Adaptive neuro-fuzzy controllers have been designed to generate a signal tocontrol the valves of the hydraulic actuators.
Turbulent Modulation in Particulate Flow: A Review of Critical Variables  [PDF]
Ammar Saber, T. Staffan Lundstr?m, J. Gunnar I. Hellstr?m
Engineering (ENG) , 2015, DOI: 10.4236/eng.2015.710054
Abstract: A review of the main mechanisms influencing turbulent modulation in the presence of spherical and non-spherical particles is presented. The review demonstrates the need for more numerical and experimental work with higher accuracy than obtained so far and the need to resolve the flow near the surface of particles with the aim to re-evaluate the quantitative effect of different parameters on turbulent modulation. The review reveals that non-spherical particles have more adverse effect on turbulence as compared to spherical ones, for the same ambient conditions.
Performance Study of a Distributed Web Server: An Analytical Approach  [PDF]
Sarah Tasneem, Reda Ammar
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.511099
Abstract: With the rapid expansion of the Internet, Web servers have played a major role in accessing the enormous mass of Web pages to find the information needed by the user. Despite the exponential growth of the WWW, a very negligible amount of research has been conducted in Web server performance analysis with a view to improve the time a Web server takes to connect, receive, and analyze a request sent by the client and then sending the answer back to client. In this paper, we propose a multi-layer analytical approach to study the web server performance. A simple client-server model is used to represent the WWW server in order to demonstrate how to apply the proposed approach. We developed a systematic, analytical methodology to quantify the communication delay and queuing overhead in a distributed web server system. The approach uses the Computation Structure Model to derive server processing time required to process a request sent from a client and queueing model to analyze the communication between the clients and the server.
Success Factors of Extracorporeal Shock Wave Lithotripsy (ESWL) for Renal & Ureteric Calculi in Adult  [PDF]
Ammar Fadil Abid
Open Journal of Urology (OJU) , 2014, DOI: 10.4236/oju.2014.43005

The purpose of this study was to define factors that have a significant impact on the stone-free rate after ESWL. Methods: A total of 417 patients harboring renal or ureteral stones underwent extracorporeal shock wave lithotripsy (ESWL) between October 2008 and July 2012. Eighty five patients were lost on follow up. The remaining (n = 332). All patients were >18 yr of age. Siemens and SLX-F2 electromagnetic machines were used to impart shock waves. Patients were stratified according to localization (pelvic, calyceal, or ureteral stones) and stone size (up to 10 mm, 10 - 20 mm, and >20 mm). Result: The overall success rate was 251/332 (75.6%) achieve stone free status. Repeated ESWL sessions were needed in 258 (61.9%). Of eleven variables were studied including age, sex, side, location (pelvic, calyx, ureter), ureteric stent, previous renal surgery, stone size, number of shock waves, opacity of stone, renal system state, and type of lithotripter, three variables were significantly affect the success rate namely stone size, number of shock waves and location of stone. Conclusions: ESWL remains one of the most commonly utilized treatments for patients with upper urinary tract calculi; Stone diameter, location, and number of shock waves, are the most important predictors determining stone clearance after ESWL of renal and ureteric calculi. To optimize treatment outcomes with ESWL the presence of treating urologist is essential to optimize the final result.

Content-Based Image Retrieval Using SOM and DWT  [PDF]
Ammar Huneiti, Maisa Daoud
Journal of Software Engineering and Applications (JSEA) , 2015, DOI: 10.4236/jsea.2015.82007
Abstract: Content-Based Image Retrieval (CBIR) from a large database is becoming a necessity for many applications such as medical imaging, Geographic Information Systems (GIS), space search and many others. However, the process of retrieving relevant images is usually preceded by extracting some discriminating features that can best describe the database images. Therefore, the retrieval process is mainly dependent on comparing the captured features which depict the most important characteristics of images instead of comparing the whole images. In this paper, we propose a CBIR method by extracting both color and texture feature vectors using the Discrete Wavelet Transform (DWT) and the Self Organizing Map (SOM) artificial neural networks. At query time texture vectors are compared using a similarity measure which is the Euclidean distance and the most similar image is retrieved. In addition, other relevant images are also retrieved using the neighborhood of the most similar image from the clustered data set via SOM. The proposed method demonstrated promising retrieval results on the Wang Database compared to the existing methods in literature.
Chemical Composition and in vitro Antimicrobial and Antioxidant Activities of Citrus aurantium L. Flowers Essential Oil (Neroli Oil)
A. Haj Ammar,J. Bouajila,A. Lebrihi,F. Mathieu
Pakistan Journal of Biological Sciences , 2012,
Abstract: Neroli essential oil is extracted from the fragrant blossoms of the bitter orange tree. It is one of the most widely used floral oils in perfumery. In this study chemical composition and in vitro antimicrobial and antioxidant activities of neroli oil are investigated. The essential oil of fresh Citrus aurantium L. Flowers (Neroli oil) cultivated in North East of Tunisia (Nabeul) were analyzed by GC-FID and GC-MS. About 33 compounds were identified, representing 99% of the total oil. Limonene (27.5%) was the main component followed by (E)-nerolidol (17.5%), α-terpineol (14%), α-terpinyl acetate (11.7%) and (E, E)-farnesol (8%). Antimicrobial activity was determined by Agar-well-diffusion method against 6 bacteria (3 Gram-positive and 3 Gram-negative), 2 yeasts and 3 fungi. Neroli oil exhibited a marked antibacterial activity especially against Pseudomonas aeruginosa. Moreover, Neroli oil exhibited a very strong antifungal activity compared with the standard antibiotic (Nystatin) as evidenced by their inhibition zones. Antioxidant activity determined by ABTS assay showed IC50 values of 672 mg L-1. Finally, this study may be considered as the first report on the biological properties of this essential oil. The results of this study have provided a starting point for the investigations to exploit new natural substances present in the essential oil of C. aurantium L. flowers.
Hybrid Amplification: An Efficient Scheme for Energy Saving in MIMO Systems  [PDF]
Gwenael Poitau, Ammar B. Kouki
Wireless Engineering and Technology (WET) , 2012, DOI: 10.4236/wet.2012.31006
Abstract: In this paper, a new amplification scheme for adaptive MIMO systems is proposed and tested. In this ‘hybrid amplification’ configuration, different amplifiers with different peak powers are used. In this way, each transmitter RF chain has a different DC-power consumption behavior. The adaptation algorithm, which chooses power and rate for each transmitter, uses these different amplifier behaviors to minimize the overall consumed energy. Several MIMO configurations designed for constant capacity applications have been simulated with different amplification schemes. Realistic amplifier models based on measured data are used. The difference between the amplifiers’ RF powers is set in order to keep optimal system performances. Then, it is shown that energy savings higher than 10% can be obtained with the hybrid amplification. The different tests are done for MQAM constellations in uncorrelated Rayleigh fading channels detected with a VBLAST ZF-SIC algorithm but can easily be extended to other correlated channels, detection algorithms or constellations.
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