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Computer Engineering Commons

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Physical Sciences and Mathematics

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2018

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Articles 331 - 342 of 342

Full-Text Articles in Computer Engineering

A Selective Frequency Reconfigurable Bandstop Metamaterial Filter For Wlan Applications, Bachir Belkadi, Zoubir Mahdjoub, Mohammed Lamine Seddiki, Mourad Nedil Jan 2018

A Selective Frequency Reconfigurable Bandstop Metamaterial Filter For Wlan Applications, Bachir Belkadi, Zoubir Mahdjoub, Mohammed Lamine Seddiki, Mourad Nedil

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, two designs of bandstop filters are presented and implemented, each one composed of a coplanar waveguide loaded with a resonator. The first design has a structure with circular resonators, and the second design is a frequency reconfigurable filter with a rectangular spiral resonator and PIN diodes. The designs are based on the use of metamaterial to create notch filters for microwave applications. The Nicolson--Ross--Weir method, used to extract the refractive index, is also described to highlight the supernatural electromagnetic characteristic of metamaterials. From the simulation results, the filters exhibit high frequency selectivity via the presence of reflection …


The Measurement Of Shielding Effectiveness For Small-In-Size Ferrite-Based Flat Materials, İsa Araz Jan 2018

The Measurement Of Shielding Effectiveness For Small-In-Size Ferrite-Based Flat Materials, İsa Araz

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents the results of our studies on the electromagnetic interference shielding effectiveness of small-in-size samples of ferrite composition microwave absorber prepared by using the ceramic method. The shielding effectiveness measurement was performed using the complex intrinsic parameters of the material. The coaxial holder method with the well-known test technique based on transmission/reflection measurements was used in the experimental setup. Complex intrinsic parameters were measured in the frequency range of 2-18 GHz by using the Nicholson - Ross - Weir (NRW) method with an automated test setup. First, the shielding effectiveness was measured by conventional test method and then …


Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, Hichem Azli, Mohamed Mostefai Jan 2018

Management Of A Hybrid Renewable Power Plant Supplying An Isolated Rural Load Within A Changing Environment, Hichem Azli, Mohamed Mostefai

Turkish Journal of Electrical Engineering and Computer Sciences

Often, authors deal with the sizing issue of hybrid power plants on horizons of several years. Proposed approaches are certainly essential to optimize energy costs. However, these solutions cannot remain optimal throughout the life cycle of the plant due to the inevitable evolution of the number of households, their consumption profiles, and possible degradation of a part of the plant. In this paper, an efficient management strategy of a sized hybrid renewable system is developed. It is based on the scheduling of the different resources of the plant. The main aim is to minimize the generated energy cost while ensuring …


Coordination Of Distance And Directional Overcurrent Relays Using A New Algorithm: Grey Wolf Optimizer, Zahra Moravej, Omid Soleimani Ooreh Jan 2018

Coordination Of Distance And Directional Overcurrent Relays Using A New Algorithm: Grey Wolf Optimizer, Zahra Moravej, Omid Soleimani Ooreh

Turkish Journal of Electrical Engineering and Computer Sciences

Optimal relay coordination has important effects on the stability, security, and reliability of a network. Hence, in this article, a method for optimal coordination of distance (D) and directional overcurrent (DOC) relays is presented. Taking into account the pickup current of the overcurrent relays as an optimization variable, in addition to the time setting multiplier (TSM) and the various characteristics of these relays, optimum and suitable settings for overcurrent and distance relays are obtained. The grey wolf optimizer algorithm has been used as an optimization tool to find optimum settings. The performance of this method has been investigated in 8-bus …


Influence Of Thyristor-Controlled Series Capacitor On Wheeling Cost Incorporating The Impact Of Real And Reactive Power Losses, Kranthi Kiran Irinjila, Jaya Laxmi Askani Jan 2018

Influence Of Thyristor-Controlled Series Capacitor On Wheeling Cost Incorporating The Impact Of Real And Reactive Power Losses, Kranthi Kiran Irinjila, Jaya Laxmi Askani

Turkish Journal of Electrical Engineering and Computer Sciences

Electric power transmission and transmission pricing are the key issues in the deregulated electric power industry. Factors like fast power demand growth, competition, service outage, and scarce natural resources make transmission systems operate close to their thermal limits. However, new transmission systems cannot be built in due to economic, environmental, and political reasons. For better utilization of existing power system capacities, the power electronic technology-based power system equipment called flexible alternating current transmission system (FACTS) devices like thyristor-controlled series compensators (TCSCs) can be effectively used for operating the transmission grid economically, rapidly, dynamically, and efficiently with increased flexibility and efficiency …


L-Index Based Contingency Filtering For Voltage Stability Constrained Reactive Power Planning, Farid Karbalaei, Shahriar Abbasi Jan 2018

L-Index Based Contingency Filtering For Voltage Stability Constrained Reactive Power Planning, Farid Karbalaei, Shahriar Abbasi

Turkish Journal of Electrical Engineering and Computer Sciences

One of the most important objectives in reactive power planning (RPP) is maintaining required voltage stability margin under normal and single-contingency situations. For this, an optimization problem must be formulated considering N-1 contingencies constrained for a set of predetermined contingencies. Traditionally, all these contingencies must simultaneously be addressed in the optimization problem. This can dramatically increase the problem dimension and decrease the convergence ability of its solution for large scale applications. This paper uses an L-index based contingency filtering strategy to select a small number of contingencies to be addressed in RPP problem. For this, the predetermined set of all …


Adaptive Antisingularity Terminal Sliding Mode Control For A Robotic Arm With Model Uncertainties And External Disturbances, Kiem Nguyen, Tinh Nguyen, Quyen Bui, Minhtuan Pham Jan 2018

Adaptive Antisingularity Terminal Sliding Mode Control For A Robotic Arm With Model Uncertainties And External Disturbances, Kiem Nguyen, Tinh Nguyen, Quyen Bui, Minhtuan Pham

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a radical adaptive terminal sliding mode control method for a robotic arm with model uncertainties and external disturbances is proposed in such a way that the singularity problem is completely dealt with. A radial basis function neural network (RBFNN) with an online weight tuning algorithm is employed to approximate unknown smooth nonlinear dynamic functions caused by the fact that there is no prior knowledge of the robotic dynamic model. Furthermore, a robust control law is utilized in order to eliminate total uncertainty composed of model uncertainties, external disturbances, and the inevitable approximation errors resulting from the finite …


Horizontal Diversity In Test Generation For High Fault Coverage, Arbab Alamgir, Abu Khari Bin A'Ain, Norlina Paraman, Usman Ullah Sheikh, Ian Grout Jan 2018

Horizontal Diversity In Test Generation For High Fault Coverage, Arbab Alamgir, Abu Khari Bin A'Ain, Norlina Paraman, Usman Ullah Sheikh, Ian Grout

Turkish Journal of Electrical Engineering and Computer Sciences

Determination of the most appropriate test set is critical for high fault coverage in testing of digital integrated circuits. Among black-box approaches, random testing is popular due to its simplicity and cost effectiveness. An extension to random testing is antirandom that improves fault detection by maximizing the distance of every subsequent test pattern from the set of previously applied test patterns. Antirandom testing uses total Hamming distance and total cartesian distance as distance metrics to maximize diversity in the testing sequence. However, the algorithm for the antirandom test set generation has two major issues. Firstly, there is no selection criteria …


A Model-Based Transformation Framework For Designing And Analyzing Wireless Sensor Networks, Raoudha Saida, Yessine Hadj Kacem, Mohammed Sulaiman Bensaleh, Mohamed Abid Jan 2018

A Model-Based Transformation Framework For Designing And Analyzing Wireless Sensor Networks, Raoudha Saida, Yessine Hadj Kacem, Mohammed Sulaiman Bensaleh, Mohamed Abid

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless sensor networks (WSNs) comprise resource-constrained (e.g., memory, processing, and energy) sensor nodes that are deployed in different areas and are able to monitor environmental conditions. Simulation has been widely used in order to evaluate the network performance. In this context, software designers need to evaluate, refine, and validate high-level models for WSN applications at early stages of development via simulation tools, in particular for WSN applications supporting energy-harvesting devices. In the present paper, we propose a model-based transformation framework that allows the modeling and simulation of a WSN system supporting energy-harvesting capabilities. In this proposal, we start from a …


A Novel Optimization Method For Solving Constrained And Unconstrained Problems: Modified Golden Sine Algorithm, Erkan Tanyildizi Jan 2018

A Novel Optimization Method For Solving Constrained And Unconstrained Problems: Modified Golden Sine Algorithm, Erkan Tanyildizi

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, the metaheuristic optimization algorithms inspired by nature and different science branches have been powerful solution methods for unconstrained, constrained, and engineering problems. Various metaheuristic optimization algorithms have been proposed and they have been applied to problems in different fields. This paper proposes a novel optimization method based on a modified version of the Golden Sine Algorithm for solving unconstrained, constrained, and engineering problems. The basic idea behind the proposed modified Golden Sine Algorithm (GoldSA-II) depends on finding the optimum solution field in search space by using the decreasing pattern of the sine function and the golden ratio. The performance …


Estimating The Selectivity Of Like Queries Using Pattern-Based Histograms, Mehmet Ayti̇mur, Ali̇ Çakmak Jan 2018

Estimating The Selectivity Of Like Queries Using Pattern-Based Histograms, Mehmet Ayti̇mur, Ali̇ Çakmak

Turkish Journal of Electrical Engineering and Computer Sciences

Accurate cost and time estimation of a query is one of the major success indicators for database management systems. SQL allows the expression of flexible queries on text-formatted data. The LIKE operator is used to search for a specified pattern (e.g., LIKE "luck %") in a string database. It is vital to estimate the selectivity of such flexible predicates for the query optimizer to choose an efficient execution plan. In this paper, we study the problem of estimating the selectivity of a LIKE query predicate over a bag of strings. We propose a new type of pattern-based histogram structure to …


A Distributed Admm Approach For Energy-Efficient Resource Allocation In Mobile Edge Computing, Weiwei Fang, Wenchen Zhou, Yangyang Li, Xuening Yao, Feng Xue, Naixue Xiong Jan 2018

A Distributed Admm Approach For Energy-Efficient Resource Allocation In Mobile Edge Computing, Weiwei Fang, Wenchen Zhou, Yangyang Li, Xuening Yao, Feng Xue, Naixue Xiong

Turkish Journal of Electrical Engineering and Computer Sciences

Mobile edge computing (MEC) is a new promising technique to provide cloud-computing capabilities at the edge of cellular networks in close proximity to mobile users. In this paper, we consider joint optimization of the communication and computation resources in a multiuser, multiserver MEC system. The objective of this optimization problem is to minimize the total energy consumption of mobile devices under the time-sharing constraint. Given the fact that no coordination is involved between mobile devices, we propose a light-weight and decentralized algorithm based on the alternating direction method of multipliers (ADMM) framework. Experimental results demonstrate that the proposed algorithm performs …