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2014

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Articles 931 - 960 of 1036

Full-Text Articles in Computer Engineering

Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan Jan 2014

Coherence Analysis On Thermal Effect For Power Cables Under Different Environmental Conditions, Sezai̇ Taşkin, Şahi̇n Serhat Şeker, Özcan Kalenderli̇, Murat Karahan

Turkish Journal of Electrical Engineering and Computer Sciences

There are 2 important aspects of this research; these are the experimental study and the data analysis, which are based on coherence analysis. In this study, a low-voltage power cable is tested under 2 different environments, air and water, and the variations in temperature are measured for the conductor, the sheath parts of the cable, and the environment. The recorded test data are analyzed using such as coherence analysis. This in turn provides the means to determine the relationship among the sheath, conductor, and the environment. In conclusion, high correlated peaks in the frequency domain are used to determine the …


Modeling And Simulation Of Deadbeat-Based Pi Controller In A Single-Phase H-Bridge Inverter For Stand-Alone Applications, Tow Leong Tiang, Dahaman Ishak Jan 2014

Modeling And Simulation Of Deadbeat-Based Pi Controller In A Single-Phase H-Bridge Inverter For Stand-Alone Applications, Tow Leong Tiang, Dahaman Ishak

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a deadbeat-based proportional-integral (PI) controller for a stand-alone single-phase voltage source inverter using a battery cell as the primary energy source. The inverter system is simulated in MATLAB/Simulink. It consists of a lead acid battery, third-order Butterworth low-pass DC filter and AC filter, H-bridge inverter, step-up transformer, and a variety of loads, as well as its sinusoidal pulse-width modulation (SPWM) deadbeat-based PI controller. In this paper, 2 simulation case studies are carried out, which are the abrupt load changes from a 400 W resistive load to a 500 W resistive load, and from a 400 W resistive …


Inverse Covariance Principal Component Analysis For Power System Stability Studies, Abdullah Alodienat, Tauseef Gulrez Jan 2014

Inverse Covariance Principal Component Analysis For Power System Stability Studies, Abdullah Alodienat, Tauseef Gulrez

Turkish Journal of Electrical Engineering and Computer Sciences

The dominant poles (eigenvalues) of system matrices are used extensively in determining the power system stability analysis. The challenge is to find an accurate and efficient way of computing these dominant poles, especially for large power systems. Here we present a novel way for finding the system stability based on inverse covariance principal component analysis (ICPCA) to compute the eigenvalues of large system matrices. The efficacy of the proposed method is shown by numerical calculations over realistic power system data and we also prove the possibility of using ICPCA to determine the eigenvalues closest to any damping ratio and repeated …


Hd-Mr: A New Algorithm For Number Recognition In Electrical Meters, Miguel Rodriguez, Geovanni Berdugo, Daladier Jabba, Maria Calle, Miguel Jimeno Jan 2014

Hd-Mr: A New Algorithm For Number Recognition In Electrical Meters, Miguel Rodriguez, Geovanni Berdugo, Daladier Jabba, Maria Calle, Miguel Jimeno

Turkish Journal of Electrical Engineering and Computer Sciences

Utility companies in developing countries employ analog electrical meters to determine consumption and bill their customers accordingly. Obtaining an accurate reading is an expensive and time-consuming process. High consumption levels of water, energy, or gas are fined by the government; thus, it is necessary to develop tools that allow users to be informed about their consumption in real time. This paper proposes a new number recognition algorithm named the Hausdorff distance for meter reading (HD-MR). Experiments prove that HD-MR can achieve a 99.9% recognition rate, even when recognized numbers are under rotation. The maximum recognition time is 31 ms; hence, …


A Novel Sms Application With Gsm Control On Numerator Systems, Ali̇ Sarikaş, Zi̇ya Ekşi̇, Cüneyt Yücelbaş, Ali̇ Buldu Jan 2014

A Novel Sms Application With Gsm Control On Numerator Systems, Ali̇ Sarikaş, Zi̇ya Ekşi̇, Cüneyt Yücelbaş, Ali̇ Buldu

Turkish Journal of Electrical Engineering and Computer Sciences

Numerator systems are widely used in various fields, sorting, and structures to ensure regular functioning. They are used today in places such as banks and hospitals to minimize the time spent waiting in a queue, and various studies have been undertaken to achieve efficiency in the workplace. At the beginning of these studies, numerator systems, which have been integrated into the short message service (SMS) application, have been used efficiently. With this application, to supply the required information to the user in the fastest way, a numerator system is developed by utilizing radio frequency communications and the SMS message structure. …


Rfid And Communication Technologies For An Intelligent Bus Monitoring And Management System, Mahammad Abdul Hannan, Aishah Mustapha, Abdulla Al Mamun, Aini Hussain, Hassan Basri Jan 2014

Rfid And Communication Technologies For An Intelligent Bus Monitoring And Management System, Mahammad Abdul Hannan, Aishah Mustapha, Abdulla Al Mamun, Aini Hussain, Hassan Basri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper highlights the implementation of an intelligent bus monitoring system based on current challenges and problems. In this system, radio frequency identification and integrated sensing technologies, such as a global positioning system, general packet radio service, and geographic information system, are used to monitor the movement of a bus. A new theoretical framework and ruled-based decision algorithms are developed for the system. An experimental setup is developed for the prototype implementation. The results show that the choice of integrated technologies used in the system is suitable to monitor and manage a vehicle transportation system.


A Methodology For Memristance Calculation, Reşat Mutlu, Ertuğrul Karakulak Jan 2014

A Methodology For Memristance Calculation, Reşat Mutlu, Ertuğrul Karakulak

Turkish Journal of Electrical Engineering and Computer Sciences

A memristor is a newly found fundamental circuit element whose behavior can be predicted using either the charge-dependent function called memristance or the flux-dependent function called memductance. Therefore, it is important to find the memristance or memductance function of a memristor. To the best of our knowledge, there is no methodology describing how to obtain the memristance function or memristor characteristic in the literature for this purpose as of yet. In this work, a methodology is suggested to find the memristance or memductance functions. The methodology suggests first doing several experiments with a memristor using a square-wave signal to acquire …


M-Fdbscan: A Multicore Density-Based Uncertain Data Clustering Algorithm, Atakan Erdem, Taflan İmre Gündem Jan 2014

M-Fdbscan: A Multicore Density-Based Uncertain Data Clustering Algorithm, Atakan Erdem, Taflan İmre Gündem

Turkish Journal of Electrical Engineering and Computer Sciences

In many data mining applications, we use a clustering algorithm on a large amount of uncertain data. In this paper, we adapt an uncertain data clustering algorithm called fast density-based spatial clustering of applications with noise (FDBSCAN) to multicore systems in order to have fast processing. The new algorithm, which we call multicore FDBSCAN (M-FDBSCAN), splits the data domain into c rectangular regions, where c is the number of cores in the system. The FDBSCAN algorithm is then applied to each rectangular region simultaneously. After the clustering operation is completed, semiclusters that occur during splitting are detected and merged to …


Increasing Key Space At Little Extra Cost In Rfid Authentications, Gökhan Dalkiliç, Mehmet Hi̇lal Özcanhan, Hafi̇ze Şen Çakir Jan 2014

Increasing Key Space At Little Extra Cost In Rfid Authentications, Gökhan Dalkiliç, Mehmet Hi̇lal Özcanhan, Hafi̇ze Şen Çakir

Turkish Journal of Electrical Engineering and Computer Sciences

Traditional authentication and key establishment protocols utilize nonce parameters as a means for message freshness, recent aliveness, and key derivation. Improving identity verification, increasing key space, or making secret updates more complex through nonces are not goals. Generating random numbers as nonces and not making the most out of them can be considered as a loss in resource stricken radio frequency identification (RFID) tags. By increasing the shared secrets slightly, a new functionality for the nonces is introduced, which makes the authentication and key establishment protocols of RFID systems more secure, in general. The proposed method contributes to the security …


A Web Laboratory Using Matlab Builder Ne For Computer Image Processing, Sezgi̇n Kaçar, Cüneyt Bayilmiş, Özdemi̇r Çeti̇n Jan 2014

A Web Laboratory Using Matlab Builder Ne For Computer Image Processing, Sezgi̇n Kaçar, Cüneyt Bayilmiş, Özdemi̇r Çeti̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Many various instruments are needed for computer image processing. These instruments are used for image restoration, analysis, etc. This paper presents a novel web laboratory based on MATLAB Builder NE with Web Figure, called ImageWeb, to facilitate computer image processing without needed technical information for users. The developed ImageWeb provides fundamental principles of image processing, including basic, compression, edge detection, filtering, optimization, and histogram processes, and so on. In addition, the usage of MATLAB Builder NE with MATLAB Web Figure provides high flexibility with visualization means such as zoom, rotate, and 3-dimensional view. Users can easily access ImageWeb using only …


Analysis Of A Rule-Based Curriculum Plan Optimization System With Spearman Rank Correlation, Di̇dem Abi̇di̇n, Hafi̇ze Şen Çakir Jan 2014

Analysis Of A Rule-Based Curriculum Plan Optimization System With Spearman Rank Correlation, Di̇dem Abi̇di̇n, Hafi̇ze Şen Çakir

Turkish Journal of Electrical Engineering and Computer Sciences

In corporations, accurate planning should be applied to manage the in-service training task within an optimum time period and without hindering the working tempo of the employees. For this reason, it is better to consider the curriculum planning task as a timetabling problem. However, when the timetables are prepared manually, it may turn out to be a complicated and time-consuming problem. In this study, it is aimed to evaluate the results of software introduced previously, which seeks to find a solution to the curriculum planning problem of in-service training programs in corporations using a rule-based genetic algorithm (GA). The input …


Effects Of A Current Transformer's Magnetizing Current On The Driving Voltage In Self-Oscillating Converters, Güngör Bal, Seli̇m Öncü Jan 2014

Effects Of A Current Transformer's Magnetizing Current On The Driving Voltage In Self-Oscillating Converters, Güngör Bal, Seli̇m Öncü

Turkish Journal of Electrical Engineering and Computer Sciences

Magnetizing inductance is one of the parameters that affect the phase and amplitude error of the output current of current transformers (CTs). In this study, the linear circuit model of a CT is developed to be used for driving purposes in power electronics applications. A simulation of the CT and its linear model is achieved. In the model circuit, the effect of the magnetizing inductance on the driving voltage can be examined. The equivalent circuit simulation results and the linear model simulation results along with the calculated results show agreement with each other. These results are compared with experimental results.


A Low-Memory Intensive Decoding Architecture For Double-Binary Convolutional Turbo Code, Ming Zhan, Liang Zhou, Jun Wu Jan 2014

A Low-Memory Intensive Decoding Architecture For Double-Binary Convolutional Turbo Code, Ming Zhan, Liang Zhou, Jun Wu

Turkish Journal of Electrical Engineering and Computer Sciences

Memory accesses take a large part of the power consumption in the iterative decoding of double-binary convolutional turbo code (DB-CTC). To deal with this, a low-memory intensive decoding architecture is proposed for DB-CTC in this paper. The new scheme is based on an improved maximum a posteriori probability algorithm, where instead of storing all of the state metrics, only a part of these state metrics is stored in the state metrics cache (SMC), and the memory size of the SMC is thus reduced by 25%. Owing to a compare-select--recalculate processing (CSRP) module in the proposed decoding architecture, the unstored state …


A New Approach In The Evaluation Of Hospital Information Systems, Güney Gürsel, Neşe Zayi̇m, Kemal Hakan Gülkesen, Ali̇ Ari̇foğlu, Osman Saka Jan 2014

A New Approach In The Evaluation Of Hospital Information Systems, Güney Gürsel, Neşe Zayi̇m, Kemal Hakan Gülkesen, Ali̇ Ari̇foğlu, Osman Saka

Turkish Journal of Electrical Engineering and Computer Sciences

Hospital information system (HIS) evaluation frameworks have largely been discussed in the literature. However, existing frameworks lack one important aspect: to what extent user expectations of HISs are met. In this study, user expectation data are collected by means of the 'expectation questionnaire'. The internal consistencies of the answers to the questionnaire are measured by Cronbach's alpha coefficient. Fuzzy logic methodologies are used to evaluate the expectation variables in the proposed evaluation framework. The evaluation variables are not represented in the results equally; they are reflected by the weights assigned by the users. Our proposed framework provides the overall degree …


Spatiotemporal Realization Of An Artificial Retina Model And Performance Evaluation Through Isi- And Spike Count-Based Image Reconstruction Methods, İrfan Karagöz, Mustafa Özden Jan 2014

Spatiotemporal Realization Of An Artificial Retina Model And Performance Evaluation Through Isi- And Spike Count-Based Image Reconstruction Methods, İrfan Karagöz, Mustafa Özden

Turkish Journal of Electrical Engineering and Computer Sciences

Development of an artificial retina model that can mimic the biologic retina is a highly challenging task and this task is an important step in the development of a visual prosthesis. The receptive field structure of the retina layer is usually modeled as a 2D difference of Gaussian (DOG) filter profile. In the present study, as a different approach, a retina model including a 3D 2-stage DOG filter (3D-ADOG) that has an adaptively changing bandwidth with respect to the local image statistic is developed. Using this modeling, the adaptive image processing of the retina can be realized. The contribution of …


A Penalty Function Method For Designing Efficient Robust Classifiers With Input Space Optimal Separating Surfaces, Ayşegül Uçar, Yakup Demi̇r, Cüneyt Güzeli̇ş Jan 2014

A Penalty Function Method For Designing Efficient Robust Classifiers With Input Space Optimal Separating Surfaces, Ayşegül Uçar, Yakup Demi̇r, Cüneyt Güzeli̇ş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper considers robust classification as a constrained optimization problem. Where the constraints are nonlinear, inequalities defining separating surfaces, whose half spaces include or exclude the data depending on their classes and the cost, are used for attaining robustness and providing the minimum volume regions specified by the half spaces of the surfaces. The constraints are added to the cost using penalty functions to get an unconstrained problem for which the gradient descent method can be used. The separating surfaces, which are aimed to be found in this way, are optimal in the input data space in contrast to the …


Multiuser Detection Using Soft Particle Swarm Optimization Along With Radial Basis Function, Muhammad Zubair, Muhammad Aamer Saleem Choudhry, Ijaz Mansoor Qureshi Jan 2014

Multiuser Detection Using Soft Particle Swarm Optimization Along With Radial Basis Function, Muhammad Zubair, Muhammad Aamer Saleem Choudhry, Ijaz Mansoor Qureshi

Turkish Journal of Electrical Engineering and Computer Sciences

The multiuser detection (MUD) problem was addressed as a pattern classification problem. Due to their strength in solving nonlinear separable problems, radial basis functions, aided by soft particle swarm optimization, were proposed to perform MUD for a synchronous direct sequence code division multiple access system. The proposed solution was shown to exhibit performance better than a number of other suboptimum detectors including the genetic algorithm and the classical particle swarm optimization algorithm.


Concurrently Attuned Design Of A Wadc-Based Upfc Psdc And Multiinput Pss For Improving Power System Dynamic Performance, Yashar Hashemi, Rasool Kazemzadeh, Mohammad Reza Azizian, Ahmad Sadeghi Yazdankhah Jan 2014

Concurrently Attuned Design Of A Wadc-Based Upfc Psdc And Multiinput Pss For Improving Power System Dynamic Performance, Yashar Hashemi, Rasool Kazemzadeh, Mohammad Reza Azizian, Ahmad Sadeghi Yazdankhah

Turkish Journal of Electrical Engineering and Computer Sciences

A new controller design for a unified power flow controller (UPFC) for damping of power system swings, focusing on interarea modes, is described in this paper. The proposed controller is a dual-layer controller, where the first layer is derived from local signals and the second layer is supplied by global signals, as additional measuring information from suitable remote network locations, where swings are well observable. For damping of low-frequency swing in wide-area operation, since there is little system information in the active power as input of the conventional power system stabilizer (CPSS), the effectiveness of the CPSS is low. For …


Current-Mode Universal Filter And Quadrature Oscillator Using Cdtas, Jie Jin, Chunhua Wang Jan 2014

Current-Mode Universal Filter And Quadrature Oscillator Using Cdtas, Jie Jin, Chunhua Wang

Turkish Journal of Electrical Engineering and Computer Sciences

A current differencing transconductance amplifier (CDTA)-based multiple-input single-output (MISO) current-mode universal filter and a quadrature oscillator (QO) are presented in this paper. The same circuit is used in the filter and oscillator, which only consists of 2 CDTAs and 2 capacitors. The universal filter can realize low-pass, high-pass, band-pass, band-stop, and all-pass biquad filter functions. With a slight modification of the filter, a new current-mode QO can be obtained easily. The natural frequency and quality factor of the filter and the conditions of oscillation and frequency of oscillation of the QO are all orthogonally adjustable through the bias currents of …


Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz Jan 2014

Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz

Turkish Journal of Electrical Engineering and Computer Sciences

High-voltage impulses (HVIs) are produced under laboratory conditions in order to emulate actual internal (switching) and external (lightning, thunderbolt) voltages. HVI resistance tests are essential to meet national and international standards on the production of electromechanical devices and materials, such as switchgears, and transformers that operate under these actual conditions. Accurate measurement of HVI is excessively difficult since the voltage level is so high, while the time parameters are relatively constricted. In this study, a reliable automatic HVI measuring and recording system, which accommodates a series of hardware and software designs in order to satisfy the constraints of the standards, …


A Novel Approach Based On Reliability Sensitivity Analysis To Allocate Protective Devices, Hamed Hashemi Dezaki, Hossein Askarian Abyaneh, Mehdi Garmrudi, Hossein Mahdinia, Kazem Mazlumi Jan 2014

A Novel Approach Based On Reliability Sensitivity Analysis To Allocate Protective Devices, Hamed Hashemi Dezaki, Hossein Askarian Abyaneh, Mehdi Garmrudi, Hossein Mahdinia, Kazem Mazlumi

Turkish Journal of Electrical Engineering and Computer Sciences

In electrical distribution systems, it is possible to have a reliable system via a well-designed protective scheme. The allocation of protective devices is an important parameter in the design of a protective scheme. Different approaches to optimize the allocation of protective devices have been studied. Because of some uncertainties, it is not the best strategy to select an optimized solution in accordance with certain conditions. The availability of the protective devices seriously affects the reliability of electrical distribution systems. Furthermore, reduction of the investment in some designing processes leads to a decrease in the number of protective devices that will …


Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic Jan 2014

Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the possibility of classifying power system dynamics events using discrete wavelet transform (DWT) and a neural network (NN) by analyzing one variable at a single network bus. Following a disturbance in the power system, it will propagate through the system in the form of low-frequency electromechanical oscillations (LFEOs) in a frequency range of up to 5 Hz. DWT allows the identification of components of the LFEO, their frequencies, and magnitudes. After determining the energy components' share of the analyzed signal using DWT and Parseval's theorem, the input data for the classification process using a NN are obtained. …


Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja Jan 2014

Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja

Turkish Journal of Electrical Engineering and Computer Sciences

A state feedback control method for an interleaved boost power converter is designed, which, in turn, can achieve interleaved current sharing among parallel-connected converters. The state feedback control in the continuous time domain is derived using the pole placement technique and linear quadratic optimal method. The load estimator is designed by deriving a full-order state observer to ensure the robustness and optimality of the state feedback control and an observer-based controller (control law plus full-order state observer) is designed using the separation principle. The adopted control strategies achieve effective output voltage regulation, good dynamic stability, and reject disturbances. Extensive simulation …


Passive Ac Network Supplying The Integration Of Ccc-Hvdc And Vsc-Hvdc Systems, Ali Bidadfar, Mehrdad Abedi, Mehdi Karrari, Gevorg .Babamalek Gharehpetian, Sanaz Namayan Tavana Jan 2014

Passive Ac Network Supplying The Integration Of Ccc-Hvdc And Vsc-Hvdc Systems, Ali Bidadfar, Mehrdad Abedi, Mehdi Karrari, Gevorg .Babamalek Gharehpetian, Sanaz Namayan Tavana

Turkish Journal of Electrical Engineering and Computer Sciences

The integration of a capacitor-commutated converter (CCC) high-voltage direct current (HVDC) (CCC-HVDC) and voltage source converter (VSC) HVDC (VSC-HVDC) is proposed in this paper to supply entirely passive AC networks. The key point of this integration is the flat characteristic of the DC voltage of the CCC-HVDC, which provides the condition for the VSC to connect to the CCC DC link via a current regulator. The advantages of the proposed combined infeeding system are the requirement of only one DC line, and better dynamic responses. The structure of the proposed infeeding system, as well as its control system, is studied. …


Luenberger Observer-Based Sensor Fault Detection: Online Application To Dc Motor, Alkan Alkaya, İlyas Eker Jan 2014

Luenberger Observer-Based Sensor Fault Detection: Online Application To Dc Motor, Alkan Alkaya, İlyas Eker

Turkish Journal of Electrical Engineering and Computer Sciences

Fault detection and diagnosis (FDD) are very important for engineering systems in industrial applications. One of the most popular approaches is model-based fault detection. Recently, many techniques have been proposed in the FDD area. However, there are still very few reported applications or real-time implementations of the schemes. This paper presents online sensor FDD based on the model-based approach using a Luenberger observer and experimental application on a permanent magnet DC motor. Different kinds of faults are simulated on the motor and experiments are performed to detect the faults. The experimental results demonstrate that this approach could significantly detect the …


Design, Optimization, And Realization Of A Wire Antenna With A 25:1 Bandwidth Ratio For Terrestrial Communications, Korkut Yeği̇n Jan 2014

Design, Optimization, And Realization Of A Wire Antenna With A 25:1 Bandwidth Ratio For Terrestrial Communications, Korkut Yeği̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Wire antennas can be made wideband if the antenna is loaded with passive elements and connected to a lossless matching network. However, realization of the load component values and matching network can easily become impractical. In this study, using only a surface mount and standard component values, antenna loads and a matching network are optimized using genetic algorithms. The optimized design achieves a 25:1 bandwidth ratio, from 20 MHz to 500 MHz, with a maximum voltage standing wave ratio (VSWR) of 3.5 and minimum system gain of --5 dBi. The antenna system gain at azimuth is taken as the objective …


A Convergent Algorithm For A Cascade Network Of Multiplexed Dual Output Discrete Perceptrons For Linearly Nonseparable Classification, İbrahi̇m Genç, Cüneyt Güzeli̇ş Jan 2014

A Convergent Algorithm For A Cascade Network Of Multiplexed Dual Output Discrete Perceptrons For Linearly Nonseparable Classification, İbrahi̇m Genç, Cüneyt Güzeli̇ş

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a new discrete perceptron model is introduced. The model forms a cascade structure and it is capable of realizing an arbitrary classification task designed by a constructive learning algorithm. The main idea is to copy a discrete perceptron neuron's output to have a complementary dual output for the neuron, and then to select, by using a multiplexer, the true output, which might be 0 or 1 depending on the given input. Hence, the problem of realization of the desired output is transformed into the realization of the selector signal of the multiplexer. In the next step, the …


Motion Clustering On Video Sequences Using A Competitive Learning Network, Sali̇h Görgünoğlu, Şafak Altay Jan 2014

Motion Clustering On Video Sequences Using A Competitive Learning Network, Sali̇h Görgünoğlu, Şafak Altay

Turkish Journal of Electrical Engineering and Computer Sciences

It is necessary to track human movements in crowded places and environments such as stations, subways, metros, and schoolyards, where security is of great importance. As a result, undesired injuries, accidents, and unusual movements can be determined and various precautionary measures can be taken against them. In this study, real-time or existing video sequences are used within the system. These video sequences are obtained from objects such as humans or vehicles, moving actively in various environments. At first, some preprocesses are made respectively, such as converting gray scale, finding the edges of the objects existing in the images, and thresholding …


How Do Hccmes Perform In Small Samples?, Mehmet Orhan, Esra Şi̇mşek Jan 2014

How Do Hccmes Perform In Small Samples?, Mehmet Orhan, Esra Şi̇mşek

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this paper is to explore the performances of prominent and popular heteroscedasticity-consistent covariance matrix estimators (HCCMEs) in small samples. The HCCMEs are selected from the literature and their ability to estimate the true covariance matrix of the coefficient's vector is evaluated through simulation runs. We calculate the percentage difference between the expected value of the HCCME and the true covariance matrix to set a convenient stage to make the comparisons under several different regression settings. The main contribution of the paper is the inclusion of the HCCMEs that have been introduced into the literature recently. We report …


Early Wakeup: Improving The Drowsy Cache Performance, Sunghoon Shim, Sungwoo Chung, Hongjun Choi, Cheol Hong Kim Jan 2014

Early Wakeup: Improving The Drowsy Cache Performance, Sunghoon Shim, Sungwoo Chung, Hongjun Choi, Cheol Hong Kim

Turkish Journal of Electrical Engineering and Computer Sciences

As process technology scales down, leakage power consumption becomes comparable to dynamic power consumption. The drowsy cache technique is known as one of the most popular techniques for reducing the leakage power consumption in the data cache. However, the drowsy cache is reported to degrade the processor performance significantly. In this paper, to maintain the performance of the processor with the drowsy cache technique, we propose an early wakeup technique, which predicts the next cache line to be requested by utilizing the way-prediction information. The proposed technique efficiently reduces the number of accesses to the cache lines in drowsy mode. …