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Search Results: 1 - 10 of 4350 matches for " Omar "
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Hard Decision-Based PWM for MIMO-OFDM Radar  [PDF]
Omar Daoud
Communications and Network (CN) , 2015, DOI: 10.4236/cn.2015.71004
Abstract: For the purpose of target localization, Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) radar has been proposed. OFDM technique has been adopted in order to a simultaneous transmission and reception of a set of multiple narrowband orthogonal signals at orthogonal frequencies. Although multi-carrier systems such as OFDM support high data rate applications, they do not only require linear amplification but also they complicate the power amplifiers design and increase power consumption. This is because of high peak-to-average power ratio (PAPR). In this work, a new proposition has been made based on the Pulse Width Modulation (PWM) to enhance the MIMO-OFDM radar systems’ performance. In order to check the proposed systems performance and its validity, a numerical analysis and a MATLAB simulation have been conducted. Nevertheless of the system characteristics and under same bandwidth occupancy and system’s specifications, the simulation results show that this work can reduce the PAPR values clearly and show capable results over the ones in the literature.
Numerical Investigation of Phase and Group Propagation of Time-Domain Signals in a Novel Band-Reject Metamaterial Ring Hybrid  [PDF]
Omar Siddiqui
Journal of Computer and Communications (JCC) , 2015, DOI: 10.4236/jcc.2015.36002
Abstract: Phase and group propagation in metamaterial-based microwave components has always been intellectually challenging for students and engineers new to the area of periodic structures and metamaterials. This paper aims in tackling this important topic by studying the wave propagation in a metamaterial-based microwave device. Hence, the contribution of this paper is twofold. First, design of a novel metamaterial ring hybrid (or rate-race) is presented which has a large rejection band so that the second and third harmonics are effectively suppressed. Second, the electromagnetic phase and the group propagation in the ring hybrid are investigated by numerically exciting the input ports with band-limited Gaussian pulses and then finding their responses at various locations in the device.
Investigation of the Quaternion Dynamical System  [PDF]
Yasmin Omar
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.51014
Abstract: The quaternion Mandelbrot set is one of the most important sets in mathematics. In this paper we first give some properties of the quaternion algebra. Then, we introduce the quternion dynamical system. We are concerned with analytical and numerical investigation of the quaternion dynamical system.
Pattern-Oriented Approach for Enterprise Architecture: TOGAF Framework  [PDF]
Mohamed Taleb, Omar Cherkaoui
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.51008
Abstract: Design pattern suggests that developers must be able to reuse proven solutions emerging from the best design practices to solve common design problems while composing patterns to create reusable designs that can be mapped to different types of enterprise frameworks and architectures such as The Open Group Architecture Framework (TOGAF). Without this, business analysts, designers and developers are not properly applying design solutions or take full benefit of the power of patterns as reuse blocks, resulting in poor performance, poor scalability, and poor usability. Furthermore, these professionals may “reinvent the wheel” when attempting to implement the same design for different types of architectures of TOGAF framework. In this paper, we introduce different categories of design patterns as a vehicle for capturing and reusing good analyses, designs and implementation applied to TOGAF framework while detailing a motivating exemplar on how design patterns can be composed to create generic types of architectures of TOGAF framework. Then, we discuss why patterns are a suitable for developing and documenting various architectures including enterprise architectures as TOGAF.
Exploring QSARs for Inhibitory Activity of Cyclic Urea and Nonpeptide-Cyclic Cyanoguanidine Derivatives HIV-1 Protease Inhibitors by Artificial Neural Network  [PDF]
Omar Deeb, Mohammad Jawabreh
Advances in Chemical Engineering and Science (ACES) , 2012, DOI: 10.4236/aces.2012.21010
Abstract: Quantitative structure–activity relationship study using artificial neural network (ANN) methodology were conducted to predict the inhibition constants of 127 symmetrical and unsymmetrical cyclic urea and cyclic cyanoguanidine derivatives containing different substituent groups such as: benzyl, isopropyl, 4-hydroxybenzyl, ketone, oxime, pyrazole, imidazole, triazole and having anti-HIV-1 protease activities. The results obtained by artificial neural network give advanced regression models with good prediction ability. The two optimal artificial neural network models obtained have coefficients of determination of 0.746 and 0.756. The lowest prediction’s root mean square error obtained is 0.607. Artificial neural networks provide improved models for heterogeneous data sets without splitting them into families. Both the external and cross-validation methods are used to validate the performances of the resulting models. Randomization test is employed to check the suitability of the models.
A Space Unrestricted Multi-Robot Combat Internet of Things System  [PDF]
Omar Said, Mehedi Masud
Advances in Internet of Things (AIT) , 2012, DOI: 10.4236/ait.2012.23007
Abstract: Multi-robot cooperation problem has received increasing attention in the research community and has been extensively studied from different aspects. Space constrain problem is a major issue for building a multi-robot system. This con- strain is a major hindrance for the efficient cooperation among robots in multi-robot applications. In this paper, we demonstrate a novel architecture of a multi-robot system without space restriction. Our architecture is based on the Internet of Things technology. We validated the proposed architecture using a case study considering a multi-robot combat application.
The Appearance of Noise Terms in Modified Adomian Decomposition Method for Quadratic Integral Equations  [PDF]
Huda Omar Bakodah
American Journal of Computational Mathematics (AJCM) , 2012, DOI: 10.4236/ajcm.2012.22017
Abstract: In this paper, we apply the modified Adomian Decomposition Method to get the numerical solutions of Quadratic integral equations. The appearance of noise terms in Decomposition Method was investigated. The method was described along with several examples.
Effect of Recharge and Irrigation on the Variation of Nitrate in the Groundwater of Wadi Djendjen (Jijel—North-East Algeria)  [PDF]
Abdelmadjid Boufekane, Omar Saighi
Journal of Water Resource and Protection (JWARP) , 2013, DOI: 10.4236/jwarp.2013.510100

This paper presents the effect of recharge and irrigation on the variation of nitrate in the groundwater of wadi Djendjen (Jijel—North-East Algeria) where the intensive use of fertilizers and the recycling of irrigation water have resulted in an alarming increase in nitrate concentrations. In this plain, the groundwater is increasingly polluted by excessive use of fertilizers in agriculture. Indeed, in several areas of irrigated vegetable crops, water contains nitrate levels which exceed the allowed standards for human consumption. The present study consists of a spatio-temporal monitoring of nitrate in groundwater in relation to the dilution caused when charging during the rainy season, on the one hand, and to the leaching by irrigation water during the dry season, on the other hand. The results obtained show an increase in the contamination of groundwater by nitrates and their seasonal variations under the effects of recharge and irrigation.

Mobile Data Mining-Based Services on the Base of Mobile Device Management (MDM) System  [PDF]
Mazin Omar Khairo
Journal of Signal and Information Processing (JSIP) , 2014, DOI: 10.4236/jsip.2014.53011

Client software on mobile devices that can cause the remote control perform data mining tasks and show production results is significantly added the value for the nomadic users and organizations that need to perform data analysis stored in the repository, far away from the site, where users work, allowing them to generate knowledge regardless of their physical location. This paper presents new data analysis methods and new ways to detect people work location via mobile computing technology. The growing number of applications, content, and data can be accessed from a wide range of devices. It becomes necessary to introduce a centralized mobile device management. MDM is a KDE software package working with enterprise systems using mobile devices. The paper discussed the design system in detail.

Method of Designing Generators of Pseudorandom Sequences for Information Protection Based on Shift Register with Non-Linear Feedback Function  [PDF]
Saleh Al-Omar
Journal of Information Security (JIS) , 2014, DOI: 10.4236/jis.2014.54020
Abstract: This paper proposes an efficient, high-tech method of construction of pseudorandom binary sequences generators with a repetition period 2n for n-bit shift register with a nonlinear feedback function. The developed method is illustrated by constructing a nonlinear function feedback shift register. It is proved that the offered method requires the realization of a memory size proportional to n2 that allows making successful use of suitable generators for practical use on the shift register of the longer word.
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