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Full-Text Articles in Computer Engineering

Optimization Design Of A Doubly Salient 8/6 Srm Based On Three Computational Intelligence Methods, Fares Rebahi, Amar Bentounsi, Houssem Rafik El-Hana Bouchekara, Redjem Rebbah Jan 2016

Optimization Design Of A Doubly Salient 8/6 Srm Based On Three Computational Intelligence Methods, Fares Rebahi, Amar Bentounsi, Houssem Rafik El-Hana Bouchekara, Redjem Rebbah

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to optimize an 8/6 doubly salient switched reluctance machine using three computational intelligence methods, which include particle swarm optimization, a genetic algorithm, and differential evolution. Three cases are investigated where different parameters are considered like the stator pole arc, rotor pole arc, and ratios, which define the stator yoke and rotor thickness. The objective functions considered are the average torque and the torque-to-weight functions. The simulations are carried out using MATLAB and FEMM software. The optimal results found are compared with the initial design, and it is shown that high improvements are achieved.


A Gis-Based Novel Active Monitoring System For Fiber Networks, Özer Koray Akdemi̇r, Taner Dursun, Sadik Arslan, Recep Benzer, Muhammet Ali̇ Akcayol Jan 2016

A Gis-Based Novel Active Monitoring System For Fiber Networks, Özer Koray Akdemi̇r, Taner Dursun, Sadik Arslan, Recep Benzer, Muhammet Ali̇ Akcayol

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a geographic information system (GIS)-based novel fiber network monitoring system has been developed to improve the operation and maintenance of fiber optic networks (FONs). The main aim of the developed system is to provide the required capabilities for both detailed digital modeling and central monitoring of FONs. The system can perform scheduled measurements and dispatch alarms if any fault or degradation is detected in the concerned FON. It also indicates the alarm locations on a map as a considerable contribution to decreasing mean time to repair. The developed monitoring system has more security features than others.


Optimization With Genetic Algorithm Of Temperature-Dependent Fiber Length Of L-Band Edfa Gain, Murat Yücel, Damt Adnan Mustafa Mustafa Jan 2016

Optimization With Genetic Algorithm Of Temperature-Dependent Fiber Length Of L-Band Edfa Gain, Murat Yücel, Damt Adnan Mustafa Mustafa

Turkish Journal of Electrical Engineering and Computer Sciences

Erbium-doped fiber amplifiers (EDFAs) have great importance in long-distance communication. It is required to have equal gain for all signals that are transferred and to avoid loss in the receiver of long-distance communication systems. However, temperature dependence changes the output spectrum of the designed gain-flattening systems. In this study, each erbium-doped fiber (EDF) length of a two-stage L-band EDFA has been optimized using a genetic algorithm method; because of the temperature dependence of EDFAs, there is no general rule. Thus, a simple, fast, dynamic, and highly accurate model has been developed and obtained for different EDF lengths that will fix …


A New Deployment Method For Electric Vehicle Charging Infrastructure, Bünyami̇n Yağciteki̇n, Mehmet Uzunoğlu, Ari̇f Karakaş Jan 2016

A New Deployment Method For Electric Vehicle Charging Infrastructure, Bünyami̇n Yağciteki̇n, Mehmet Uzunoğlu, Ari̇f Karakaş

Turkish Journal of Electrical Engineering and Computer Sciences

The fast depletion of fossil fuels, climate change, and global warming have become major worldwide problems and alternatives for conventional transportation have been actively researched in the last decade. Compared to available conventional vehicles, electric vehicles have a leading position due to their environmentally friendly transportation. Recent electric vehicle penetration brings the necessity of a high number of charging stations, which are considered to be established in community areas such as shopping centers, hospitals, commercial areas, university campuses, residential areas, and streets. Deployment planning of charging stations is very important for driver expectations and social and economic impacts of electric …


Modeling And Performance Optimization Of Photovoltaic And Thermal Collector Hybrid System, Di̇lşad Engi̇n, Meti̇n Çolak Jan 2016

Modeling And Performance Optimization Of Photovoltaic And Thermal Collector Hybrid System, Di̇lşad Engi̇n, Meti̇n Çolak

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the hybrid photovoltaic/thermal collector (PV/T) system's electrical and thermal efficiency was examined by stating a mathematical model and developing a prototype of the system. To enhance the electrical efficiency, the cell temperature of the PV module was decreased with cooling and the heated fluid could be used for low heating applications. For this purpose, a PV/T system was modeled and constructed using a thermal collector placed beneath the photovoltaic panel where the excess heat and solar radiation through the transparent PV module was the input of the thermal collector. A transparent solar module was used in order …


Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi Jan 2015

Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an active-reactive power control strategy for voltage source converters (VSCs) based on derivation of the direct and quadrature components of the VSC output current. The proposed method utilizes a multivariable proportional-integral controller and provides almost completely decoupled control capability of the active and reactive power with almost full disturbance rejection due to step changes in the power exchanged between the VSC and the grid. It also imposes fast transient response and zero steady-state error as compared to the conventional power control approaches. The applicability of the proposed power control strategy for providing the robust stability of the …


Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko Jan 2015

Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a method for determination of equivalent linear electromagnetic parameters (constant complex permeability and electrical conductivity) of nonlinear magnetic steel, which can be used in a time-harmonic finite-element simulation to yield the same losses in the volume of that material as the measured ones. The conductivity and the static hysteresis loop of the steel have been measured, from which complex permeability as a function of flux density has been extracted. The indirect measurement of losses in various samples of nonmagnetic and magnetic steel has been carried out using a physical model of a transformer core with a coil. …


A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou Jan 2014

A Reduced Probabilistic Neural Network For The Classification Of Large Databases, Abdelhadi Lotfi, Abdelkader Benyettou

Turkish Journal of Electrical Engineering and Computer Sciences

The probabilistic neural network (PNN) is a special type of radial basis neural network used mainly for classification problems. Due to the size of the network after training, this type of network is usually used for problems with a small-sized training dataset. In this paper, a new training algorithm is presented for use with large training databases. Application to the handwritten digit database shows that the reduced PNN performs better than the standard PNN for all of the studied cases with a big gain in size and processing speed. This new type of neural network can be used easily for …


Optimization Of Job Shop Scheduling Problems Using Modified Clonal Selection Algorithm, Yilmaz Atay, Hali̇fe Kodaz Jan 2014

Optimization Of Job Shop Scheduling Problems Using Modified Clonal Selection Algorithm, Yilmaz Atay, Hali̇fe Kodaz

Turkish Journal of Electrical Engineering and Computer Sciences

Artificial immune systems (AISs) are one of the artificial intelligence techniques studied a lot in recent years. AISs are based on the principles and mechanisms of the natural immune system. In this study, the clonal selection algorithm, which is used commonly in AISs, is modified. This algorithm is applied to job shop scheduling problems, which are one of the most difficult optimization problems. For applying application results to the optimum solution, parameter values giving the optimum solution are determined by analyzing the parameters in the algorithm. The obtained results are given in detail in the tables and figures. The best …


Optimized Operation And Maintenance Costs To Improve System Reliability By Decreasing The Failure Rate Of Distribution Lines, Hamed Hashemi Dezaki, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Seyed Mohammad Mousavi Agah Jan 2013

Optimized Operation And Maintenance Costs To Improve System Reliability By Decreasing The Failure Rate Of Distribution Lines, Hamed Hashemi Dezaki, Seyed Hossein Hosseinian, Hossein Askarian Abyaneh, Seyed Mohammad Mousavi Agah

Turkish Journal of Electrical Engineering and Computer Sciences

Improving distribution system reliability has received a great deal of attention in recent years. Because of the limitation in expected budgets, it is desirable to determine the most efficient strategy to improve system reliability. This paper proposes a novel method to determine the optimized operation and maintenance costs in order to decrease the failure of system components. The proposed objective function includes the average system frequency interruption index (ASIFI) value. To achieve the best strategy to decrease failures of system components, it is necessary to find the minimum value of the objective function, considering the constraints of operation and maintenance …


Data Hiding In Digital Images Using A Partial Optimization Technique Based On The Classical Lsb Method, Feyzi̇ Akar, Yildiray Yalman, Hüseyi̇n Selçuk Varol Jan 2013

Data Hiding In Digital Images Using A Partial Optimization Technique Based On The Classical Lsb Method, Feyzi̇ Akar, Yildiray Yalman, Hüseyi̇n Selçuk Varol

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new partial optimization approach for the least significant bit (LSB) data hiding technique that can be used for protecting any secret information or data. A deterioration effect of as little as possible in an image is intended using the LSB data hiding technique and this is well realized utilizing the proposed partial optimization approach achieving the same data embedding bit rates. In the proposed approach, all of the image pixels are classified into 8 regions and then the 8 distinct ordering codings are applied to each region by the developed partial optimization encoder. Thus, the most …


Optimal Placement And Sizing Of Distributed Generations In Distribution Systems For Minimizing Losses And Thd_V Using Evolutionary Programming, Aida Fazliana Abdul Kadir, Azah Mohamed, Hussain Shareef, Mohd Zamri Che Wanik Jan 2013

Optimal Placement And Sizing Of Distributed Generations In Distribution Systems For Minimizing Losses And Thd_V Using Evolutionary Programming, Aida Fazliana Abdul Kadir, Azah Mohamed, Hussain Shareef, Mohd Zamri Che Wanik

Turkish Journal of Electrical Engineering and Computer Sciences

Growing concerns over environmental impacts, improvement of the overall network conditions, and rebate programs offered by governments have led to an increase in the number of distributed generation (DG) units in commercial and domestic electric power production. However, a large number of DG units in a distribution system may sometimes contribute to high levels of harmonic distortion, even though the emission levels of the individual DG units comply with the harmonic standards. It is known that the nonoptimal size and nonoptimal placement of DG units may lead to high power losses, bad voltage profiles, and harmonic propagations. Therefore, this paper …


Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar Jan 2012

Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a differential evolution (DE) algorithm for optimizing the placement and power of the pilot tones that are utilized by a least square (LS) algorithm for channel estimation in multiple-input and multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. Computer simulations demonstrated that the performance of the LS algorithm was increased by optimizing the pilot tones with the DE algorithm instead of locating them orthogonally. We used the upper bound of the mean square error (MSE) as a fitness function of the DE algorithm for optimization tasks. With the use of an upper bound, it is not necessary …


Change Detection Without Difference Image Computation Based On Multiobjective Cost Function Optimization, Turgay Çeli̇k, Zeki̇ Yetgi̇n Jan 2011

Change Detection Without Difference Image Computation Based On Multiobjective Cost Function Optimization, Turgay Çeli̇k, Zeki̇ Yetgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a novel method for unsupervised change detection in multi-temporal satellite images by using multiobjective cost function optimization via genetic algorithm (GA). The spatial image grid of the input multi-temporal satellite images is divided into two distinct regions, representing ``changed'' and ``unchanged'' regions between input images, via the intermediate change detection mask produced by the GA. The dissimilarity of pixels of ``changed'' regions and similarity of pixels of ``unchanged'' regions between input multi-temporal images are measured using image quality metrics which consider correlation, spectral distortion, radiometric distortion, and contrast distortion. The contextual information of each pixel …


An Approach Based On Particle Swarm Computation To Study The Nanoscale Dg Mosfet-Based Circuits, Fayacl Djeffal, Toufik Bendib, Redha Benzid, Abdelhamid Benhaya Jan 2010

An Approach Based On Particle Swarm Computation To Study The Nanoscale Dg Mosfet-Based Circuits, Fayacl Djeffal, Toufik Bendib, Redha Benzid, Abdelhamid Benhaya

Turkish Journal of Electrical Engineering and Computer Sciences

The analytical modeling of nanoscale Double-Gate MOSFETs (DG) requires generally several necessary simplifying assumptions to lead to compact expressions of current-voltage characteristics for nanoscale CMOS circuits design. Further, progress in the development, design and optimization of nanoscale devices necessarily require new theory and modeling tools in order to improve the accuracy and the computational time of circuits' simulators. In this paper, we propose a new particle swarm strategy to study the nanoscale CMOS circuits. The latter is based on the 2-D numerical Non-Equilibrium Green's Function (NEGF) simulation and a new extended long channel DG MOSFET compact model. Good agreement between …


Softcomputing Identification Techniques Of Asynchronous Machine Parameters: Evolutionary Strategy And Chemotaxis Algorithm, Nouri Benaïdja Jan 2009

Softcomputing Identification Techniques Of Asynchronous Machine Parameters: Evolutionary Strategy And Chemotaxis Algorithm, Nouri Benaïdja

Turkish Journal of Electrical Engineering and Computer Sciences

Softcomputing techniques are receiving attention as optimisation techniques for many industrial applications. Although these techniques eliminate the need for derivatives computation, they require much work to adjust their parameters at the stage of research and development. Issues such as speed, stability, and parameters convergence remain much to be investigated. This paper discusses the application of the method of reference model to determine parameters of asynchronous machines using two optimisation techniques. Softcomputing techniques used in this paper are evolutionary strategy and the chemotaxis algorithm. Identification results using the two techniques are presented and compared with respect to the conventional simplex technique …


Parameter Identification Of A Separately Excited Dc Motor Via Inverse Problem Methodology, Mounir Hadef, Mohamed Rachid Mekideche Jan 2009

Parameter Identification Of A Separately Excited Dc Motor Via Inverse Problem Methodology, Mounir Hadef, Mohamed Rachid Mekideche

Turkish Journal of Electrical Engineering and Computer Sciences

Identification is considered to be among the main applications of inverse theory and its objective for a given physical system is to use data which is easily observable, to infer some of the geometric parameters which are not directly observable. In this paper, a parameter identification method using inverse problem methodology is proposed. The minimisation of the objective function with respect to the desired vector of design parameters is the most important procedure in solving the inverse problem. The conjugate gradient method is used to determine the unknown parameters, and Tikhonov's regularization method is then used to replace the original …


Analysis And Optimization Of Mobile Phone Antenna Radiation Performance In The Presence Of Head And Hand Phantoms, Erdem Ofli, Chung-Huan Li, Nicolas Chavannes, Niels Kuster Jan 2008

Analysis And Optimization Of Mobile Phone Antenna Radiation Performance In The Presence Of Head And Hand Phantoms, Erdem Ofli, Chung-Huan Li, Nicolas Chavannes, Niels Kuster

Turkish Journal of Electrical Engineering and Computer Sciences

A commercial clam shell phone CAD model is used to numerically investigate the effect of a hand phantom on mobile phone antenna radiation performance. The simulation results show that the grip of the hand phantom is the most important parameter to antenna performance. The antenna is converted into a parameterized form, then optimized to achieve the targeted multi-band performance in real-usage conditions.


A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem Jan 2004

A Simple And Global Optimization Algorithm For Engineering Problems: Differential Evolution Algorithm, Dervi̇ş Karaboğa, Selçuk Ökdem

Turkish Journal of Electrical Engineering and Computer Sciences

Differential Evolution (DE) algorithm is a new heuristic approach mainly having three advantages; finding the true global minimum regardless of the initial parameter values, fast convergence, and using few control parameters. DE algorithm is a population based algorithm like genetic algorithms using similar operators; crossover, mutation and selection. In this work, we have compared the performance of DE algorithm to that of some other well known versions of genetic algorithms: PGA, Grefensstette, Eshelman. In simulation studies, De Jong's test functions have been used. From the simulation results, it was observed that the convergence speed of DE is significantly better than …