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2013

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Articles 2011 - 2040 of 2092

Full-Text Articles in Computer Sciences

A New Extension Of Activity Networks For Modeling And Verification Of Timed Systems, Hassan Motallebi, Mohammad Abdollahi Azgomi, Mohammad Saber Mirzaei, Ali Movaghar Jan 2013

A New Extension Of Activity Networks For Modeling And Verification Of Timed Systems, Hassan Motallebi, Mohammad Abdollahi Azgomi, Mohammad Saber Mirzaei, Ali Movaghar

Turkish Journal of Electrical Engineering and Computer Sciences

Stochastic activity networks (SANs) are a well-known petri net-based formalism used for the performance and dependability modeling of a wide range of systems. On the other hand, the growing complexity of timed systems makes it imperative to apply formal analysis techniques in the early stages of the system's development. Finding a suitable framework for the modeling, evaluation, and verification of these systems is still a great challenge. In this paper, we introduce a new formalism named timed activity networks (TANs), which are based on the activity networks that are the nondeterministic settings of the SANs. The advantages of TANs are …

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Cada: Channel And Delay Aware Scheduler For Real-Time Applications In Wimax Networks, Melek Oktay, Haci Ali̇ Mantar Jan 2013

Cada: Channel And Delay Aware Scheduler For Real-Time Applications In Wimax Networks, Melek Oktay, Haci Ali̇ Mantar

Turkish Journal of Electrical Engineering and Computer Sciences

Scheduling is the core of the worldwide interoperability for microwave access (WiMAX) technology that directly affects the performance of the network. In this study, we focus on scheduling and present a novel algorithm called the channel and delay aware scheduler (CADA) for real-time applications, such as voice over Internet protocol, video-on-demand, and video streaming. CADA has 2 important modules: wireless and network delay monitoring tools. The wireless module, including the compensation and channel state monitoring modules, increases the network throughput and provides fairness among all of the flows in the network. The network delay monitoring tool calculates the estimated network …

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An Improved Back Projection Imaging Algorithm For Subsurface Target Detection, Wentai Lei, Sheng Zeng, Jian Zhao, Qianzhe Wang, Jianxin Liu Jan 2013

An Improved Back Projection Imaging Algorithm For Subsurface Target Detection, Wentai Lei, Sheng Zeng, Jian Zhao, Qianzhe Wang, Jianxin Liu

Turkish Journal of Electrical Engineering and Computer Sciences

An improved back projection imaging algorithm for subsurface target detection is presented in this paper. Firstly, the characteristic of the scattering data at each time-delay curve in the traditional back projection imaging procedure is analyzed. Secondly, a weight factor is designed for each focal point and an improved back projection imaging algorithm is presented. Thirdly, the simulation of the improved imaging algorithm is processed. The imaging results of both the simulation data and the real ground penetrating radar data show the effectiveness of this imaging algorithm.

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Outlier Rejection Fuzzy C-Means (Orfcm) Algorithm For Image Segmentation, Fasahat Ullah Siddiqui, Nor Ashidi Mat Isa, Abid Yahya Jan 2013

Outlier Rejection Fuzzy C-Means (Orfcm) Algorithm For Image Segmentation, Fasahat Ullah Siddiqui, Nor Ashidi Mat Isa, Abid Yahya

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a fuzzy clustering-based technique for image segmentation. Many attempts have been put into practice to increase the conventional fuzzy c-means (FCM) performance. In this paper, the sensitivity of the soft membership function of the FCM algorithm to the outlier is considered and the new exponent operator on the Euclidean distance is implemented in the membership function to improve the outlier rejection characteristics of the FCM. The comparative quantitative and qualitative studies are performed among the conventional k-means (KM), moving KM, and FCM algorithms; the latest state-of-the-art clustering algorithms, namely the adaptive fuzzy moving KM , adaptive fuzzy …

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Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya Jan 2013

Survey Of Power Quality In Turkish National Transmission Network, Celal Kocatepe, Bedri̇ Kekezoğlu, Altuğ Bozkurt, Recep Yumurtaci, Aslan İnan, Oktay Arikan, Mustafa Baysal, Yener Akkaya

Turkish Journal of Electrical Engineering and Computer Sciences

Harmonic distortion and flicker severity have become the main concerns in power transmission networks. Different types of harmonic and flicker sources exist in power systems, such as arc furnaces and cycloconverters. A power quality problem found in networks can cause additional temperature rise, losses, noise, and irritation in the lighting equipment. The aim of this study is to identify the level of harmonics and flicker in the 380-kV transmission network of Turkey. The measurement and analysis are performed using a specially developed power quality analyzer. The effects of harmonics and flicker on the network are discussed based on real measurement …

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Improving Power Systems Operation Through Multiobjective Optimal Location Of Optimal Unified Power Flow Controller, Afshin Lashkar Ara, Ahad Kazemi, Mohammad Behshad Jan 2013

Improving Power Systems Operation Through Multiobjective Optimal Location Of Optimal Unified Power Flow Controller, Afshin Lashkar Ara, Ahad Kazemi, Mohammad Behshad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a multiobjective optimization methodology to find the optimal location for an optimal unified power flow controller (OUPFC) device. Moreover, the installation cost function of the OUPFC device is developed. The objective functions are the total fuel cost, power losses, and system loadability with and without the minimum cost of the OUPFC installation. The \varepsilon-constraint approach is implemented for the multiobjective mathematical programming formulation. The proposed algorithm is implemented in the IEEE 30- and 118-bus test systems. The solution procedure uses nonlinear programming to optimally locate the OUPFC incorporated in an optimal power flow problem considering these objective …

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Adaptive Detection Of Chaotic Oscillations In Ferroresonance Using Modified Extended Kalman Filter, Cengi̇z Polat Uzunoğlu, Mukden Uğur Jan 2013

Adaptive Detection Of Chaotic Oscillations In Ferroresonance Using Modified Extended Kalman Filter, Cengi̇z Polat Uzunoğlu, Mukden Uğur

Turkish Journal of Electrical Engineering and Computer Sciences

Power quality and power disturbances have become an important factor for power systems. Chaotic ferroresonance is one of the disturbances that may cause overvoltages and overcurrents; hence, it can endanger the system reliability and continuous safe operating. A power system that generates chaotic oscillations is a dynamic system, which can be modeled with a Duffing equation. This paper introduces the application of a modified extended Kalman filter for improving the detection of chaotic behavior of power system signals. A modification algorithm is used to increase the estimation performance of the former casual extended Kalman filter. The proposed method is employed …

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Simulation Of Discrete Electromagnetic Propagation Model For Atmospheric Effects On Mobile Communication, Şaban Seli̇m Şeker, Fulya Kunter Jan 2013

Simulation Of Discrete Electromagnetic Propagation Model For Atmospheric Effects On Mobile Communication, Şaban Seli̇m Şeker, Fulya Kunter

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless communication has become an important part of our lives, and atmospheric effects are one of the ultimate factors affecting quality of communication and satellite systems. In this study the attenuation in mobile communication due to atmospheric events like snow and rain is simulated using the discrete propagation model. In this work, spherical raindrop and oblate spheroid raindrop modeling are used. To check the validity of simulations, the commonly used and accepted ITU-R rain model is used. Oblate spheroid raindrop modeling produces results that are more compatible with ITU-R results, especially at frequencies higher than 50 GHz. At lower frequencies, …

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A New Method Based On Sensitivity Analysis To Optimize The Placement Of Ssscs, Hamed Hashemi Dezaki, Masoud Mohammadalizadeh Shabestary, Hossein Askarian Abyaneh, Gevorg Babamalek Gharehpetian, Mehdi Garmrudi Jan 2013

A New Method Based On Sensitivity Analysis To Optimize The Placement Of Ssscs, Hamed Hashemi Dezaki, Masoud Mohammadalizadeh Shabestary, Hossein Askarian Abyaneh, Gevorg Babamalek Gharehpetian, Mehdi Garmrudi

Turkish Journal of Electrical Engineering and Computer Sciences

The flexible altering current transmission system (FACTS) controllers such as static synchronous series compensators (SSSCs) and unified power flow controllers can strongly improve the different parameters of power systems. They can be used to improve the transient stabilities, voltage profiles, lines transmission capabilities, etc. Therefore, the optimized allocation of FACTS devices is an important issue in recent research. The optimal placements of FACTS devices can have a determinant effect on the performance of a system, too. In this paper, the proper allocation of SSSCs is proposed. Sensitivity analysis is used in order to model SSSCs' effects on the power system. …

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A 5-Bit 5 Gs/S Flash Adc Using Multiplexer-Based Decoder, Oktay Aytar, Ali̇ Tangel, Kudret Şahi̇n Jan 2013

A 5-Bit 5 Gs/S Flash Adc Using Multiplexer-Based Decoder, Oktay Aytar, Ali̇ Tangel, Kudret Şahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a 5-bit flash analog-to-digital converter design using the 0.18-\mu m Taiwan Semiconductor Manufacturing Company's CMOS technology library. The designed system consists of 2 main blocks, a comparator array, and a digital decoder. The digital decoder contains a latch, 1-of-N decoder, and fat-tree encoder units. The 1-of-N decoder is implemented using 2 \times 1 multiplexers. As a result, the active die area and the power consumption are reduced, in addition to an increase in the sampling frequency. The power supply voltage range for the overall system is \pm 0.9 V. For testing purposes, a ramp signal of between …

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Using The Csm And Vsm Techniques To Speed Up The Ica Algorithm Without A Loss Of Quality, Mahdi Mahdikhani, Mohammad Hosein Kahaei Jan 2013

Using The Csm And Vsm Techniques To Speed Up The Ica Algorithm Without A Loss Of Quality, Mahdi Mahdikhani, Mohammad Hosein Kahaei

Turkish Journal of Electrical Engineering and Computer Sciences

In blind source separation problems that are implemented based on the independent component analysis (ICA) algorithm, the separation speed and quality are related inversely. In this paper, the proposed algorithms eliminate this tradeoff by generating a faster separation while maintaining the quality. In the proposed algorithms, in each frequency bin and in all of the learning steps, the separation quality of the separating matrix is compared with another one that we define as a situated matrix, and the best matrix is considered as an initial separating matrix in the next learning step. In this paper, we propose 2 algorithms based …

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Comparison Of Speech Parameterization Techniques For The Classification Of Speech Disfluencies, Chong Yen Fook, Hariharan Muthusamy, Lim Sin Chee, Sazali Bin Yaacob, Abdul Hamid Bin Adom Jan 2013

Comparison Of Speech Parameterization Techniques For The Classification Of Speech Disfluencies, Chong Yen Fook, Hariharan Muthusamy, Lim Sin Chee, Sazali Bin Yaacob, Abdul Hamid Bin Adom

Turkish Journal of Electrical Engineering and Computer Sciences

Stuttering assessment through the manual classification of speech disfluencies is subjective, inconsistent, time-consuming, and prone to error. The aim of this paper is to compare the effectiveness of the 3 speech feature extraction methods, mel-frequency cepstral coefficients, linear predictive coding (LPC)-based cepstral parameters, and perceptual linear predictive (PLP) analysis, for classifying 2 types of speech disfluencies, repetition and prolongation, from recorded disfluent speech samples. Three different classifiers, the k-nearest neighbor classifier, linear discriminant analysis-based classifier, and support vector machine, are employed for the classification of speech disfluencies. Speech samples are taken from the University College London Archive of Stuttered Speech …

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Fuzzified Artificial Bee Colony Algorithm For Nonsmooth And Nonconvex Multiobjective Economic Dispatch Problem, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon Jan 2013

Fuzzified Artificial Bee Colony Algorithm For Nonsmooth And Nonconvex Multiobjective Economic Dispatch Problem, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon

Turkish Journal of Electrical Engineering and Computer Sciences

The economic dispatch (ED) problem is one of the important optimization problems in power system operation. Recently the power system has stressed the need for reliable, nonpolluting, and economic operation. Hence, 3 conflicting functions of reliability, emission, and fuel cost are considered in the objective function of the proposed ED problem. The problem is formulated as a nonsmooth and nonconvex problem when the valve-point effects of thermal units are considered in the proposed reliable emission and economic dispatch (REED) problem. This paper presents a multiobjective optimization methodology for solving the newly developed REED problem using a fuzzified artificial bee colony …

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An Efficient Solving Of The Traveling Salesman Problem: The Ant Colony System Having Parameters Optimized By The Taguchi Method, Musa Peker, Baha Şen, Pinar Yildiz Kumru Jan 2013

An Efficient Solving Of The Traveling Salesman Problem: The Ant Colony System Having Parameters Optimized By The Taguchi Method, Musa Peker, Baha Şen, Pinar Yildiz Kumru

Turkish Journal of Electrical Engineering and Computer Sciences

Owing to its complexity, the traveling salesman problem (TSP) is one of the most intensively studied problems in computational mathematics. The TSP is defined as the provision of minimization of total distance, cost, and duration by visiting the n number of points only once in order to arrive at the starting point. Various heuristic algorithms used in many fields have been developed to solve this problem. In this study, a solution was proposed for the TSP using the ant colony system and parameter optimization was taken from the Taguchi method. The implementation was tested by various data sets in the …

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Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz Jan 2013

Detection Of Microcalcification Clusters In Digitized X-Ray Mammograms Using Unsharp Masking And Image Statistics, Peli̇n Kuş, İrfan Karagöz

Turkish Journal of Electrical Engineering and Computer Sciences

A fully automated method for detecting microcalcification (MC) clusters in regions of interest (ROIs) extracted from digitized X-ray mammograms is proposed. In the first stage, an unsharp masking is used to perform the contrast enhancement of the MCs. In the second stage, the ROIs are decomposed into a 2-level contourlet representation and the reconstruction is obtained by eliminating the low-frequency subband in the second level. In the third stage, statistical textural features are extracted from the ROIs and they are classified using support vector machines. To test the performance of the method, 57 ROIs selected from the Mammographic Image Analysis …

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Discovery Of The Connection Among Age-Related Macular Degeneration, Mthfr C677t And Pai 1 4g/5g Gene Polymorphisms, And Body Mass Index By Means Of Bayesian Inference Methods, Aydan Çelebi̇ler, Huseyin Seker, Bora Yüksel, Ahmet Orun, Si̇bel Bi̇lgi̇li̇, Muhammet Baysal Karaca Jan 2013

Discovery Of The Connection Among Age-Related Macular Degeneration, Mthfr C677t And Pai 1 4g/5g Gene Polymorphisms, And Body Mass Index By Means Of Bayesian Inference Methods, Aydan Çelebi̇ler, Huseyin Seker, Bora Yüksel, Ahmet Orun, Si̇bel Bi̇lgi̇li̇, Muhammet Baysal Karaca

Turkish Journal of Electrical Engineering and Computer Sciences

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in the elderly. The aim of this study was therefore to explore the relationship between the presence of multiple gene polymorphisms and 2 distinct advanced `dry and wet' AMD phenotypes, and to assess gene interactions with the influence of personal factors in a Turkish population as a pilot study. For the analysis, the data were collected from 73 unrelated participants, grouped as 29 wet and 26 dry AMD patients, and 18 healthy controls. They were all genotyped for the multiple gene polymorphisms in 12 different genes. The data set …

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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 …

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A New Intelligent Classifier For Breast Cancer Diagnosis Based On A Rough Set And Extreme Learning Machine: Rs + Elm, Yilmaz Kaya Jan 2013

A New Intelligent Classifier For Breast Cancer Diagnosis Based On A Rough Set And Extreme Learning Machine: Rs + Elm, Yilmaz Kaya

Turkish Journal of Electrical Engineering and Computer Sciences

Breast cancer is one of the leading causes of death among women all around the world. Therefore, true and early diagnosis of breast cancer is an important problem. The rough set (RS) and extreme learning machine (ELM) methods were used collectively in this study for the diagnosis of breast cancer. The unnecessary attributes were discarded from the dataset by means of the RS approach. The classification process by means of ELM was performed using the remaining attributes. The Wisconsin Breast Cancer dataset (WBCD), derived from the University of California Irvine machine learning database, was used for the purpose of testing …

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Novel Approaches For Automated Epileptic Diagnosis Using Fcbf Selection And Classification Algorithms, Baha Şen, Musa Peker Jan 2013

Novel Approaches For Automated Epileptic Diagnosis Using Fcbf Selection And Classification Algorithms, Baha Şen, Musa Peker

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new application for automated epileptic detection using the fast correlation-based feature (FCBF) selection and classification algorithms. This study consists of 3 stages: feature extraction, feature selection from electroencephalography (EEG) signals, and the classification of these signals. In the feature extraction phase, 16 attribute algorithms are used in 5 categories, and 36 feature parameters are obtained from these algorithms. In the feature selection phase, the FCBF algorithm is chosen to select a set of attributes that best represent the EEG signals. The resulting attributes are used as input parameters for the classification algorithms. In the classification phase, …

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Anfis-Based Estimation Of Pv Module Equivalent Parameters: Application To A Stand-Alone Pv System With Mppt Controller, Ahmet Afşi̇n Kulaksiz Jan 2013

Anfis-Based Estimation Of Pv Module Equivalent Parameters: Application To A Stand-Alone Pv System With Mppt Controller, Ahmet Afşi̇n Kulaksiz

Turkish Journal of Electrical Engineering and Computer Sciences

The performance and system cost of photovoltaic (PV) systems can be improved by employing high-efficiency power conditioners with maximum power point tracking (MPPT) methods. Fast implementation and accurate operation of MPPT controllers can be realized by modeling the characteristics of PV modules, obtaining equivalent parameters. In this study, adaptive neuro-fuzzy inference systems (ANFISs) have been used to obtain 3 of the parameters in a single-diode model of PV cells, namely series resistance, shunt resistance, and diode ideality factor. The input parameters of ANFISs are a material-type of PV modules, short circuit current, open circuit voltage, and unit area under the …

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Adaptive Control Of A Time-Varying Rotary Servo System Using A Fuzzy Model Reference Learning Controller With Variable Adaptation Gain, Ömer Aydoğdu, Özdemi̇r Alkan Jan 2013

Adaptive Control Of A Time-Varying Rotary Servo System Using A Fuzzy Model Reference Learning Controller With Variable Adaptation Gain, Ömer Aydoğdu, Özdemi̇r Alkan

Turkish Journal of Electrical Engineering and Computer Sciences

The constant parameters in a conventional fuzzy controller lead to a poor performance for time-varying systems. In this study, a fuzzy model reference learning controller (FMRLC) with a newly defined variable adaptation gain is designed and implemented in the adaptive fuzzy control of a time-varying rotary servo (TVRS) system. In the design of the FMRLC, a knowledge-base modification algorithm with variable adaptation gain is used instead of a fuzzy relation table. Hence, it is provided that the learning and adaptation mechanism continuously updates the knowledge base of the adaptive fuzzy controller against any parameter variations, such as changing loads. By …

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Power Efficient Linear Transmitters Using Sigma-Delta Modulation With Switching Amplifiers, Tayfun Nesimoglu Jan 2013

Power Efficient Linear Transmitters Using Sigma-Delta Modulation With Switching Amplifiers, Tayfun Nesimoglu

Turkish Journal of Electrical Engineering and Computer Sciences

In conventional envelope elimination and restoration transmitters, the envelope information of the carrier is reconstructed by modulating the supply voltage of the switching amplifier. In this paper, it is shown that the supply voltage modulation introduces nonlinearity and reduces the average power efficiency of the transmitter. Here, novel transmitter architectures using sigma-delta--modulated carrier signals are proposed to overcome these shortcomings. The proposed architecture's and conventional envelope elimination and restoration transmitter's linearity and efficiency performances are compared at various oversampling rates and signal bandwidths. It is demonstrated that the proposed architectures may provide better linearity and efficiency than conventional envelope elimination …

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Prediction Of Emissions And Exhaust Temperature For Direct Injection Diesel Engine With Emulsified Fuel Using Ann, Görkem Kökkülünk, Erhan Akdoğan, Vezi̇r Ayhan Jan 2013

Prediction Of Emissions And Exhaust Temperature For Direct Injection Diesel Engine With Emulsified Fuel Using Ann, Görkem Kökkülünk, Erhan Akdoğan, Vezi̇r Ayhan

Turkish Journal of Electrical Engineering and Computer Sciences

Exhaust gases have many effects on human beings and the environment. Therefore, they must be kept under control. The International Convention for the Prevention of Pollution from Ships (MARPOL), which is concerned with the prevention of marine pollution, limits the emissions according to the regulations. In Emission Control Area (ECA) regions, which are determined by MARPOL as ECAs, the emission rates should be controlled. Direct injection (DI) diesel engines are commonly used as a propulsion system on ships. The prediction and control of diesel engine emission rates is not an easy task in real time. Therefore, in this study, an …

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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 …

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A Low-Voltage And Low-Power Sinh-Domain Universal Biquadratic Filter For Low-Frequency Applications, Farooq Khanday, Nisar Shah Jan 2013

A Low-Voltage And Low-Power Sinh-Domain Universal Biquadratic Filter For Low-Frequency Applications, Farooq Khanday, Nisar Shah

Turkish Journal of Electrical Engineering and Computer Sciences

Sinh-domain CMOS filters have favorable properties, such as a wide dynamic range at low supply voltage, compactness, linearity, and low power consumption. These properties are becoming increasingly important for biomedical applications that require extremely low-power dissipation and neuromorphic circuits that attempt to reproduce the biophysics of biological neurons and synapses. In this paper, a low-voltage sinh-domain universal biquadratic filter circuit is introduced. The circuit, aside from permitting the independent adjustment of pole frequency (\omega_0) and the quality factor (Q), is free from matching conditions, capable of absorbing the shunt parasitic capacitances, amenable for monolithic integration, and composed of merely a …

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Design Of Information Retrieval Experiments: The Sufficient Topic Set Size For Providing An Adequate Level Of Confidence, Beki̇r Taner Di̇nçer Jan 2013

Design Of Information Retrieval Experiments: The Sufficient Topic Set Size For Providing An Adequate Level Of Confidence, Beki̇r Taner Di̇nçer

Turkish Journal of Electrical Engineering and Computer Sciences

In the current design of information retrieval (IR) experiments, a sample of 50 topics is generally agreed to be sufficient in size to perform dependable system evaluations. This article presents the detailed and formal explanation of how the second fundamental theorem of probability, the central limit theorem, can be used for the estimation of the sufficient size of a topic sample. The research performed in this article, using past Text Retrieval Conference data, reveals that, on average, 50 topics will be sufficient to provide a confidence level at or above 95% if the null hypothesis of an equal population mean …

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Control Of Diesel Engines Mounted On Vehicles In Mobile Cranes Via Can Bus, Muci̇z Özcan, Hi̇dayet Günay Jan 2013

Control Of Diesel Engines Mounted On Vehicles In Mobile Cranes Via Can Bus, Muci̇z Özcan, Hi̇dayet Günay

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the aim was to lift loads that required more force using the infrastructure of existing vehicles. To this end, a truck-mounted diesel engine was selected to be used in mobile crane applications. A control system was designed and implemented to obtain the appropriate hydraulic force by accessing the diesel engine with a controller area network bus via an electronic control unit (ECU). For this purpose, hydraulic pumps to be used to operate the crane were mounted on the selected mobile diesel engine with an ECU. Firms that manufacture cranes in the world produce cranes with infrastructure. This …

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A Novel Dynamic Bandwidth Selection Method For Thinning Noisy Point Clouds, Mehmet Öztürk, Zeynep Hasirci Jan 2013

A Novel Dynamic Bandwidth Selection Method For Thinning Noisy Point Clouds, Mehmet Öztürk, Zeynep Hasirci

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a dynamic bandwidth selection method for thinning noisy point clouds into curves. Due to the nonhomogeneous distribution of noise or varying curvature of the data, the thinning procedure requires a dynamically adjusted bandwidth along the curve. On the other hand, the selected local region must be sorted along a suitable direction vector for local curve fitting purposes. The contribution of this paper to the field is 2-folded: first, a normalized eigenvalue analysis-based method is used to determine the best local bandwidth. The second task is getting a good regression line of the local region for …

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Compact Microstrip Antenna With Metamaterial For Wideband Applications, Han Xiong, Jing-Song Hong, Ming-Tao Tan, Bing Li Jan 2013

Compact Microstrip Antenna With Metamaterial For Wideband Applications, Han Xiong, Jing-Song Hong, Ming-Tao Tan, Bing Li

Turkish Journal of Electrical Engineering and Computer Sciences

An improved metamaterial antenna, with a compact size of 27.8 x 31.9 x 0.794 mm^3, fed by an offset-microstrip line, is proposed. The total size is slightly reduced and the measured impedance bandwidth is 4.08-7.83 GHz for a return loss of \mid S_{11}\mid < -10 dB. Compared with the original patch antenna, the bandwidth of the proposed antenna is 550 MHz broader and has a lower resonant frequency. The simulated gain of the antenna is more than 2 dB, with a peak of about 6 dB at 6.8 GHz. Moreover, the antenna has strong radiation in the horizontal direction for some specific applications within the entire band.

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Stopping Spam With Sending Session Verification, Ahmet Baran Jan 2013

Stopping Spam With Sending Session Verification, Ahmet Baran

Turkish Journal of Electrical Engineering and Computer Sciences

Spam has become one of the most significant problems for Internet communication and users today. The traditional filtering methods and signature-based spam blocking systems that have come into prominence recently fall short, as statistics demonstrate that spam further mounts up day after day. In this study, a new method is recommended to block spam mails. In this recommended method, a mail sending session is verified during mail envelope communication by adding small attachments to the simple mail transfer protocol, so spam mails can be blocked before leaving the sender domain or relay machine. Additionally, hijacked user accounts are able to …

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