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2016

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Articles 1291 - 1320 of 1427

Full-Text Articles in Computer Engineering

Behavior-Based Detection Of Application Layer Distributed Denial Of Service Attacks During Flash Events, Renukadevi Saravanan, Saraswathi Shanmuganathan, Yogesh Palanichamy Jan 2016

Behavior-Based Detection Of Application Layer Distributed Denial Of Service Attacks During Flash Events, Renukadevi Saravanan, Saraswathi Shanmuganathan, Yogesh Palanichamy

Turkish Journal of Electrical Engineering and Computer Sciences

Distributed denial of service (DDoS) attacks are ever threatening to the developers and users of the Internet. DDoS attacks targeted at the application layer are especially difficult to be detected since they mimic the legitimate users' requests. The situation becomes more serious when they occur during flash events. A more sophisticated algorithm is required to detect such attacks during a flash crowd. A few existing works make use of flow similarity for differentiating flash crowds and DDoS, but flow characteristics alone cannot be used for effective detection. In this paper, we propose a novel mechanism for discriminating DDoS and flash …

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Research On Switched Reluctance Machine Drive Topology And Control Strategies For Electric Vehicles, He Cheng, Hao Chen, Lei Ma, Guojun Yu Jan 2016

Research On Switched Reluctance Machine Drive Topology And Control Strategies For Electric Vehicles, He Cheng, Hao Chen, Lei Ma, Guojun Yu

Turkish Journal of Electrical Engineering and Computer Sciences

The electric drive system is one of the key technologies for electric vehicles. First, the energy flow of an electric vehicle is analyzed in the driving, braking, and charging working states. After that, a drive topology that can achieve 3 working states is proposed based on the driving characteristics of a switched reluctance machine. In the driving state, the boost mode of a front-end converter is used to achieve different operating conditions, including low speed with a light load or high speed with a heavy load. In the braking state, the front-end converter is used to implement smooth switching between …

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Chattering-Eliminated Adaptive Sliding-Mode Control: An Experimental Comparison Study, Murat Furat, İlyas Eker Jan 2016

Chattering-Eliminated Adaptive Sliding-Mode Control: An Experimental Comparison Study, Murat Furat, İlyas Eker

Turkish Journal of Electrical Engineering and Computer Sciences

The present paper deals with a new adaptive sliding-mode control. The switching and equivalent control laws include adaptive gains. An error-dependent adaptive gain in the switching control law and an adaptive parameter in the equivalent control law with respect to open-loop transient response of the system are proposed to eliminate chattering and to increase the performance of the controller. The proposed approach results in chattering elimination without using any complex calculation-based methods, which is highly useful for practical applications. The number of independent gains is also minimized. Therefore, tuning of those gains is simplified. The proposed controller is compared experimentally …

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Sensorless Velocity And Direction Angle Control Of An Unmanned Vehicle, Adnan Derdi̇yok, Abdullah Başçi̇ Jan 2016

Sensorless Velocity And Direction Angle Control Of An Unmanned Vehicle, Adnan Derdi̇yok, Abdullah Başçi̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper an observer based on measured and estimated currents and a kinematic model is designed to estimate the velocity and direction angle of an unmanned vehicle (UV). The Lyapunov stability theory is used to establish the stability conditions for the observer. It is shown that the observer will converge in a finite time and the observer gains satisfy the constraints of the stability conditions. The observed velocity and direction angle are used in the closed loop instead of measured ones for sensorless control of the UV. The velocity and direction angle control of the UV are carried out …

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A 2.4-Ghz Highly Linear Derivative Superposition Gilbert Cell Mixer, Samaneh Sedighi, Omid Hashemipour, Massoud Dousti Jan 2016

A 2.4-Ghz Highly Linear Derivative Superposition Gilbert Cell Mixer, Samaneh Sedighi, Omid Hashemipour, Massoud Dousti

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new derivative superposition Gilbert cell to minimize the third-order nonlinear current term of transconductance transistors. To decrease the parasitic capacitance effect on gain, noise figure, and linearity of the circuit, extra inductors and capacitors are added between the switching and transconductance stages. The proposed mixer is simulated in 0.18-$\mu $m RF-CMOS technology with a 1.8-V supply. The results show an improvement of about 23 dBm in IIP3 compared to conventional mixers. The power consumption of this circuit is about 3.96 mW.

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Solving Multimodal Optimization Problems Based On Efficient Partitioning Of Genotypic Search Space, Atabak Mashhadi Kashtiban, Sohrab Khanmohammadi, Kayvan Asghari Jan 2016

Solving Multimodal Optimization Problems Based On Efficient Partitioning Of Genotypic Search Space, Atabak Mashhadi Kashtiban, Sohrab Khanmohammadi, Kayvan Asghari

Turkish Journal of Electrical Engineering and Computer Sciences

Enhancing the exploration and exploitation of multimodal optimization is still an interesting and challenging problem in optimization. Here we present a new population-based evolutionary algorithm for multiple optimal determinations. The approach is simply based on partitioning the genotypic search space and running a simple genetic algorithm with a small population within each partition. To increase the efficiency of the algorithm, the first-order discrete derivative of the fitness function for elite solutions was used to omit extra solutions. If the derivative of the fitness function is larger than a specified gradient threshold, no optimum exists within a given partition, and no …

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A Distributed Map Animation Framework For Spatiotemporal Datasets, Ahmet Sayar Jan 2016

A Distributed Map Animation Framework For Spatiotemporal Datasets, Ahmet Sayar

Turkish Journal of Electrical Engineering and Computer Sciences

Maps are an excellent way to present data that have spatial components. However, when the data being presented vary over time, a simple two-dimensional map ignores an important feature of the data. An animated map that shows a series of two-dimensional maps at successive points in time allows one to add a time dimension to the display of data. The current study proposes a distributed service-oriented architecture to create map animations from spatiotemporal datasets. We extend the open standards GIS web services definitions with a topic-based publish-subscribe paradigm, which best suits the animation requirements. The effectiveness of the technique is …

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Design And Analysis Of A Novel Uwb Bandpass Filter Using 3-D Em Simulation-Based Neural Network Model With Hsa, Sali̇h Demi̇rel, Cafer Uyanik Jan 2016

Design And Analysis Of A Novel Uwb Bandpass Filter Using 3-D Em Simulation-Based Neural Network Model With Hsa, Sali̇h Demi̇rel, Cafer Uyanik

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new systematic analysis and design of the ultrawide-band bandpass filter by using the 3-D electromagnetic simulation-based multilayer perceptron neural network (MLP NN) model of unit elements. This MLP NN model is utilized efficiently as a fast and accurate model within a harmony search algorithm (HSA) procedure to determine the resultant optimum microstrip structure geometry. Moreover, the validity and efficiency of the HSA is manifested by comparing it with those of the standard metaheuristics, which are genetic and particle swarm algorithms. The filter that shows the best performance is designed and realized. Measurements taken from the realized …

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An Improved Security Framework For Web Service-Based Resources, Wenbin Jiang, Hui Xu, Hao Dong, Hai Jin, Xiaofei Liao Jan 2016

An Improved Security Framework For Web Service-Based Resources, Wenbin Jiang, Hui Xu, Hao Dong, Hai Jin, Xiaofei Liao

Turkish Journal of Electrical Engineering and Computer Sciences

Web service-based application has become one of the dominative ones of the Internet. This trend brings more and more security challenges in reliability, confidentiality, and data nonrepudiation, especially in some systems that have massive diversified resources. An improved framework for secure accesses of Web resources is presented and implemented by extending and enhancing the Spring Security framework. It improves the security level of systems for identity authentication, authorized access, and secure transmission. The highly safe authentication is based on the integration of an improved authentication module of Spring Security with a U-key method and a RSA algorithm. For authorized access, …

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Study Of Temperature Distribution In Light--Tissue Interaction Using The Fem, Ahmet Yasi̇n Çi̇tkaya, Şaban Seli̇m Şeker Jan 2016

Study Of Temperature Distribution In Light--Tissue Interaction Using The Fem, Ahmet Yasi̇n Çi̇tkaya, Şaban Seli̇m Şeker

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the numerical modeling of interaction between light sources and living biological tissue is studied. One of the most important results of physical interactions of light with biological tissue are thermal changes, which are a consequence of absorption of light. The severity of the effects is dependent upon several factors, including exposure duration, wavelength of the beam, beam energy, tissue type, and the area that is exposed to the beam. The temperature response of tissue irradiation is governed by the extensively used Pennes bioheat equation in a 3-dimensional space. The Pennes equation is solved initially for a single-layer …

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Comprehensive Review Of Association Estimators For The Inference Of Gene Networks, Zeyneb Kurt Yavuz, Ni̇zametti̇n Aydin, Gökmen Altay Jan 2016

Comprehensive Review Of Association Estimators For The Inference Of Gene Networks, Zeyneb Kurt Yavuz, Ni̇zametti̇n Aydin, Gökmen Altay

Turkish Journal of Electrical Engineering and Computer Sciences

Gene network inference (GNI) algorithms allow us to explore the vast amount of interactions among the molecules in cells. In almost all GNI algorithms the main process is to estimate association scores among the variables of the dataset. However, there is no commonly accepted estimator to compute association scores for the current GNI algorithms. In this paper the association estimators that might be used in GNI applications are reviewed. The aim is to prepare a comprehensive and comparative review of all the important association estimators available in the literature. We performed this main aim by presenting, classifying, comparing, and discussing …

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Design Of A High-Linear, High-Precision Analog Multiplier, Free From Body Effect, Ali Naderi Saatlo, İsmai̇l Serdar Özoğuz Jan 2016

Design Of A High-Linear, High-Precision Analog Multiplier, Free From Body Effect, Ali Naderi Saatlo, İsmai̇l Serdar Özoğuz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new CMOS four-quadrant analog multiplier circuit is proposed, based on a pair of dual-translinear loops. The significant features of the circuit are its high accuracy and high linearity as well as its body effect-free operation, owing to the fact that the circuit relies on a new dual-translinear topology. In addition, harmonic distortions are precisely discussed due to their conceivable mismatches, including transconductance and threshold voltage of the transistors. HSPICE postlayout simulation results are presented to verify the validity of the theoretical analysis, where under a supply voltage of 2.8 V, the bandwidth of the proposed multiplier …

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Feature Selection For Movie Recommendation, Zehra Çataltepe, Mahi̇ye Uluyağmur, Esengül Tayfur Jan 2016

Feature Selection For Movie Recommendation, Zehra Çataltepe, Mahi̇ye Uluyağmur, Esengül Tayfur

Turkish Journal of Electrical Engineering and Computer Sciences

TV users have an abundance of different movies they could choose from, and with the quantity and quality of data available both on user behavior and content, better recommenders are possible. In this paper, we evaluate and combine different content-based and collaborative recommendation methods for a Turkish movie recommendation system. Our recommendation methods can make use of user behavior, different types of content features, and other users' behavior to predict movie ratings. We gather different types of data on movies, such as the description, actors, directors, year, and genre. We use natural language processing methods to convert the Turkish movie …

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A Mapreduce-Based Distributed Svm Algorithm For Binary Classification, Ferhat Özgür Çatak, Mehmet Erdal Balaban Jan 2016

A Mapreduce-Based Distributed Svm Algorithm For Binary Classification, Ferhat Özgür Çatak, Mehmet Erdal Balaban

Turkish Journal of Electrical Engineering and Computer Sciences

Although the support vector machine (SVM) algorithm has a high generalization property for classifying unseen examples after the training phase~and a small loss value, the algorithm is not suitable for real-life classification and regression problems. SVMs cannot solve hundreds of thousands of examples in a training dataset. In previous studies on distributed machine-learning algorithms, the SVM was trained in a costly and preconfigured computer environment. In this research, we present a MapReduce-based distributed parallel SVM training algorithm for binary classification problems. This work shows how to distribute optimization problems over cloud computing systems with the MapReduce technique. In the second …

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Discriminant-Based Bistability Analysis Of A Tmg-Induced Lac Operon Model Supported With Boundedness And Local Stability Results, Nesli̇han Avcu, Güleser Kalayci Demi̇r, Ferhan Pekergi̇n, Hakan Alyürük, Levent Çavaş, Cüneyt Güzeli̇ş Jan 2016

Discriminant-Based Bistability Analysis Of A Tmg-Induced Lac Operon Model Supported With Boundedness And Local Stability Results, Nesli̇han Avcu, Güleser Kalayci Demi̇r, Ferhan Pekergi̇n, Hakan Alyürük, Levent Çavaş, Cüneyt Güzeli̇ş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the results of a theoretical and numerical study on the analysis of bistable behavior of the most studied gene regulatory network, the lac operon, in terms of the model parameters. The boundedness of the state variables for the considered model are demonstrated, the parameter values providing the existence of the multiple equilibria and thus the bistable behavior are determined, and a local stability analysis of the equilibria is performed. The parameter region yielding the existence of multiple equilibria is determined in an algebraic way based on discriminants. The model given in the state equation form is defined …

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Sizing Design And Implementation Of A Flywheel Energy Storage System For Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r Jan 2016

Sizing Design And Implementation Of A Flywheel Energy Storage System For Space Applications, Kutlay Aydin, Mehmet Ti̇mur Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Flywheel energy storage systems have become an important research subject in recent years. They are also considered for space applications instead of hazardous and bulky electrochemical batteries. In this paper, a flywheel energy storage system has been designed for satellite attitude control systems. Power requirements of a small commercial satellite have been used as the starting point of the design. The designed system includes a BLDC motor. The machine is run as a motor for 60 min and the stored energy is discharged during the following 30 min to simulate low orbit satellite operation. Experimental results show that these systems …

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Walsh Series Modeling And Estimation In Sensorless Position Control Of Electrical Drives, Hamidreza Shirazi, Jalal Nazarzadeh Jan 2016

Walsh Series Modeling And Estimation In Sensorless Position Control Of Electrical Drives, Hamidreza Shirazi, Jalal Nazarzadeh

Turkish Journal of Electrical Engineering and Computer Sciences

High-performance electrical drives can be achieved by using field-oriented controllers, which make torque and flux naturally decoupled. A conventional vector-controlled drive has the disadvantage of either requiring flux and speed sensors or being affected by rotor resistance, which varies along with the motor performance. The presented paper focuses on developing a high-performance sensorless rotor flux-oriented controller of an induction machine independent of the rotor resistance variation. This method applies spectral theory of Walsh functions, which are one of the most helpful members of piecewise constant basis functions in solving dynamic models. Inherent characteristics of Walsh functions and application of an …

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Quantitative Information Extraction From Gas Sensor Data Using Principal Component Regression, Ahmet Özmen, Beki̇r Mumyakmaz, Mehmet Ali̇ Ebeoğlu, Ci̇hat Taşaltin, İlke Gürol, Zafer Zi̇ya Öztürk, Deni̇z Dural Jan 2016

Quantitative Information Extraction From Gas Sensor Data Using Principal Component Regression, Ahmet Özmen, Beki̇r Mumyakmaz, Mehmet Ali̇ Ebeoğlu, Ci̇hat Taşaltin, İlke Gürol, Zafer Zi̇ya Öztürk, Deni̇z Dural

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel use of the principal component analysis (PCA) and regression methods for quantitative feature extraction from gas sensor data. In this approach, PCA plots are interpreted by observing the locations of samples in the principal component domain. A trainable data processing system that also produces numerical output is designed to validate the method. The main advantages of this system are: 1) retrainability: once it is trained, it can be used for any gas set; 2) flexibility: adaptation to different targets does not require hardware modifications (if a sufficient number and variety of sensors are installed in …

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A Parametric Study On Privatization Revenues Of The Electricity Distribution Companies In Turkey, Ercan İzgi̇, Seli̇m Ay Jan 2016

A Parametric Study On Privatization Revenues Of The Electricity Distribution Companies In Turkey, Ercan İzgi̇, Seli̇m Ay

Turkish Journal of Electrical Engineering and Computer Sciences

The privatization of electricity distribution companies in the state monopoly has increased significantly in recent years. Privatization is expected to improve the quality of services in the electric distribution sector and to provide additional income to the state. In this paper the privatization revenues of the 18 electricity distribution companies in Turkey are calculated through regression equations. The privatization revenues of the electricity distribution companies are identified by 5 models containing microeconomic and macroeconomic variables (parameters). The study indicates a correlation between the considered variables and the privatization revenues of the electricity distribution companies and useful parametric formulations are proposed. …

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A Novel Key Distribution Scheme Against Storage-Bounded Adversaries Using Attack Probabilities, Mohammad Farhadi Bajestani, Ali Payandeh Jan 2016

A Novel Key Distribution Scheme Against Storage-Bounded Adversaries Using Attack Probabilities, Mohammad Farhadi Bajestani, Ali Payandeh

Turkish Journal of Electrical Engineering and Computer Sciences

Key establishment proves to be a challenging problem in wireless sensor networks. A key establishment scheme needs to incorporate properties like scalability and energy efficiency. We propose a scheme that, besides enjoying a desirable scalability, consumes resources according to attack probability within each region. In this scheme, the distribution area is divided into regions of varying attack probability. It is assumed that the adversary is storage bounded and that not all communications can be stored by the adversary. This scheme is highly resistant to node compromises and there is an extremely low probability of discovering the key by the adversary …

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Speciation-Based Genetic Algorithm In Analog Circuit Design, Hasari̇ Karci̇, Gülay Tohumoğlu, Ari̇f Nacaroğlu Jan 2016

Speciation-Based Genetic Algorithm In Analog Circuit Design, Hasari̇ Karci̇, Gülay Tohumoğlu, Ari̇f Nacaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a speciation procedure that improves the local search capability of the genetic algorithm in analog circuit design. There is no need for additional circuit simulation in order to apply this procedure. The procedure is tested in Gaussian, sigmoid, cube, and square circuit design problems. Two sets of 125 simulations with the same seed values are performed for each problem using both the proposed procedure and the canonical genetic algorithm. The simulation results show that the method is statistically better than the canonical genetic algorithm, which suffers from bad locality. The effects of the population size and speciation …

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Square Root Central Difference-Based Fastslam Approach Improved By Differential Evolution, Haydar Ankişhan, Fi̇kret Ari, Emre Öner Tartan, Ahmet Güngör Pakfi̇li̇z Jan 2016

Square Root Central Difference-Based Fastslam Approach Improved By Differential Evolution, Haydar Ankişhan, Fi̇kret Ari, Emre Öner Tartan, Ahmet Güngör Pakfi̇li̇z

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a new approach to improve the performance of FastSLAM. The aim of the study is to obtain a more robust algorithm for FastSLAM applications by using a Kalman filter that uses Stirling's polynomial interpolation formula. In this paper, some new improvements have been proposed; the first approach is the square root central difference Kalman filter-based FastSLAM, called SRCD-FastSLAM. In this method, autonomous vehicle (or robot) position, landmarks' position estimations, and importance weight calculations of the particle filter are provided by the SRCD-Kalman filter. The second approach is an improved version of the SRCD-FastSLAM in which particles are …

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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 …

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Development Of Radiometer Operating Between 50 Mhz And 26.5 Ghz Using Gain-Stabilized Lna, Murat Celep, Şenel Yaran, Cem Hayirli, Ari̇f Dolma Jan 2016

Development Of Radiometer Operating Between 50 Mhz And 26.5 Ghz Using Gain-Stabilized Lna, Murat Celep, Şenel Yaran, Cem Hayirli, Ari̇f Dolma

Turkish Journal of Electrical Engineering and Computer Sciences

A radiometer operating between 50 MHz and 26.5 GHz and consisting of microwave channels all with a low-noise amplifier (LNA) was established. Microwave switches were used to select an appropriate channel according to measurement frequency. The effect of variations both in input and output reflection coefficients on LNA gain was investigated. To keep the change in the gain of the LNA at minimum, the LNA output was terminated with a load whose impedance was equal to that of matched load. This technique gives the opportunity of full-band noise measurements of noise sources with one total power radiometer. The performance of …

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An Advanced Optimization Technique For Considering Reliability Issues And Unit Commitment Problems Simultaneously, Ahmad Heidari, Mohammad Reza Alizadeh Pahlavani, Hamid Dehghani Jan 2016

An Advanced Optimization Technique For Considering Reliability Issues And Unit Commitment Problems Simultaneously, Ahmad Heidari, Mohammad Reza Alizadeh Pahlavani, Hamid Dehghani

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an advanced optimization technique to solve unit commitment problems and reliability issues simultaneously for thermal generating units. To solve unit commitment, generalized Benders decomposition along with a genetic algorithm are proposed to include minimum up/down time constraints, and for reliability issues consideration, a fuzzy stochastic-based technique is presented. To implement the problem into an optimization program, MATLAB software and CPLEX and KNITRO solvers are applied. To verify the proposed technique and algorithm, two case studies, the IEEE 14- and 118-bus systems, are implemented for optimal generation scheduling and reliability issues. Finally, a comparison with other solution techniques …

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Variations And Relations Of Meteorological Parameters Between Upwind And Downwind Small-Scale Wind Turbine Rotor Area, Ercan İzgi̇, Mustafa Kemal Kaymak, Ahmet Öztopal, Bi̇hter Durna, Ahmet Duran Şahi̇n Jan 2016

Variations And Relations Of Meteorological Parameters Between Upwind And Downwind Small-Scale Wind Turbine Rotor Area, Ercan İzgi̇, Mustafa Kemal Kaymak, Ahmet Öztopal, Bi̇hter Durna, Ahmet Duran Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Renewable energy sources are becoming increasingly important due to climate change and the energy crisis. Wind energy projects and applications in particular have been growing recently. Meteorological parameters such as wind speed, ambient temperature, relative humidity, and air pressure directly affect wind turbine electricity generation. Understanding the relationships among these parameters is necessary to determine wind energy potential and to predict electricity generation. The current work is based on data obtained from a 1.5 kW wind turbine constructed in İstanbul Technical University's meteorological park in Turkey. A one minute time interval was used in the data analysis. In this study, …

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Artificial Bee Colony Algorithm Based Optimal Reactive Power Flow Of Two-Terminal Hvdc Systems, Ulaş Kiliç, Kürşat Ayan Jan 2016

Artificial Bee Colony Algorithm Based Optimal Reactive Power Flow Of Two-Terminal Hvdc Systems, Ulaş Kiliç, Kürşat Ayan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a solution technique for the optimal reactive power flow (ORPF) of alternating current-direct current (AC-DC) power systems using the artificial bee colony (ABC) algorithm. A high voltage direct current (HVDC) transmission link is one of the most important network components in AC-DC power systems. In recent years there has been an increasing number of studies related to power systems with HVDC transmission links. One of them is the reactive power flow (RPF) optimization. The aim of ORPF in alternating current (AC) or AC-DC power systems is to minimize transmission line power loss under equality and inequality constraints. …

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A Classification Of Semantic Conflicts In Heterogeneous Web Services At Message Level, Ibrahim Ahmed Al Baltah, Abdul Azim Abdul Ghani, Wan Nurhayati Wan Ab Rahman, Rodziah Atan Jan 2016

A Classification Of Semantic Conflicts In Heterogeneous Web Services At Message Level, Ibrahim Ahmed Al Baltah, Abdul Azim Abdul Ghani, Wan Nurhayati Wan Ab Rahman, Rodziah Atan

Turkish Journal of Electrical Engineering and Computer Sciences

Since the last decade, semantic conflicts have been considered as a critical problem in establishing seamless message exchange between Web services. To provide the essential step for solving this problem, semantic conflicts have to be defined and classified properly. Most of the existing classifications that attempt to classify semantic conflicts lack completeness and accuracy. Therefore, this paper aims at proposing a new complete and accurate semantic conflicts classification, whose purposes are identifying and classifying all potential conflicts that may arise in heterogeneous Web services at the message level. This classification has three main classes based on the cause of conflicts, …

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An Application Of Simulated Annealing To Optimal Transcranial Direct Current Stimulation Of The Human Brain, Raheleh Tavakoli, Hamed Sadjedi, Seyyed Mohammad Pourmir Firoozabadi Jan 2016

An Application Of Simulated Annealing To Optimal Transcranial Direct Current Stimulation Of The Human Brain, Raheleh Tavakoli, Hamed Sadjedi, Seyyed Mohammad Pourmir Firoozabadi

Turkish Journal of Electrical Engineering and Computer Sciences

Transcranial direct current stimulation (tDCS) is known as the most effective technique for stimulating deeper brain areas. The capability of tDCS, however, strongly depends on the number of electrodes, their positions, and the amount of injected currents. This paper intends to apply the simulated annealing algorithm for determining optimal stimulation parameters in a multiple electrode scheme. The objective of the presented approach is to maximize the current density delivered to the target area under safety constraints. In order for the skin under the electrodes to be protected against temperature rises that may be caused by the stimulation, current injections are …

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An Unsupervised Heterogeneous Log-Based Framework For Anomaly Detection, Asif Iqbal Hajamydeen, Nur Izura Udzir, Ramlan Mahmod, Abdul Azim Abdul Ghani Jan 2016

An Unsupervised Heterogeneous Log-Based Framework For Anomaly Detection, Asif Iqbal Hajamydeen, Nur Izura Udzir, Ramlan Mahmod, Abdul Azim Abdul Ghani

Turkish Journal of Electrical Engineering and Computer Sciences

Log analysis is a method to identify intrusions at the host or network level by scrutinizing the log events recorded by the operating systems, applications, and devices. Most work contemplates a single type of log for analysis, leading to an unclear picture of the situation and difficulty in deciding the existence of an intrusion. Moreover, most existing detection methods are knowledge-dependent, i.e. using either the characteristics of an anomaly or the baseline of normal traffic behavior, which limits the detection process to only anomalies based on the acquired knowledge. To discover a wide range of anomalies by scrutinizing various logs, …

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