Open Access. Powered by Scholars. Published by Universities.®

Computer Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

47,979 Full-Text Articles 58,560 Authors 18,956,363 Downloads 350 Institutions

All Articles in Computer Sciences

Faceted Search

47,979 full-text articles. Page 1672 of 1677.

Fault Detection And Identification For Voltage Sag State Estimation In Power Systems, JAMAL BEIZA, SEYED HOSSEIN HOSSEINIAN, BEHROOZ VAHIDI 2010 TÜBİTAK

Fault Detection And Identification For Voltage Sag State Estimation In Power Systems, Jamal Beiza, Seyed Hossein Hosseinian, Behrooz Vahidi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel approach for fault detection and identification in order to estimate voltage sag during a fault. One of the best approaches for voltage sag estimation is instantaneous voltage estimation. The approach uses traditional state estimation where redundant measurements are available. The proposed method is used to estimate voltage sag performance during a fault. At the fault duration, the grid topology is changed. In such a case the measurement matrix must be re-determined at the fault duration. The proposed approach is an efficient method for fault detection and identification which is based on residual analysis and topology …


Sdre Optimal Control Of Drug Administration In Cancer Treatment, MEHMET İTİK, METİN UYMAZ SALAMCİ, STEPHEN PAUL BANKS 2010 TÜBİTAK

Sdre Optimal Control Of Drug Administration In Cancer Treatment, Mehmet İti̇k, Meti̇n Uymaz Salamci̇, Stephen Paul Banks

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, we apply State Dependent Riccati Equation (SDRE) based optimal control technique to a nonlinear tumor growth model. The model consists of three biological cells which are normal tissue, tumor and immune cells. The effect of chemotherapy treatment is also included in the model. Chemotherapy administration is considered as a control input to the nonlinear cancer dynamics and the amount of administered drug is determined by using SDRE optimal control. The optimal control is applied to the model in order not only to drive the tumor cells to the healthy equilibrium state but also to minimize the amount …


Asynchronous Particle Swarm Optimization-Based Search With A Multi-Robot System: Simulation And Implementation On A Real Robotic System, SALİH BURAK AKAT, VEYSEL GAZİ, LINO MARQUES 2010 TÜBİTAK

Asynchronous Particle Swarm Optimization-Based Search With A Multi-Robot System: Simulation And Implementation On A Real Robotic System, Sali̇h Burak Akat, Veysel Gazi̇, Lino Marques

Turkish Journal of Electrical Engineering and Computer Sciences

In this article we consider a version of the Particle Swarm Optimization (PSO) algorithm which is appropriate for search tasks of multi-agent systems consisting of small robots with limited sensing capability. The proposed method adopts asynchronous mechanism for information exchange and position (way point) updates of the agents. Moreover, at each (information exchange) step the agents communicate with only a possibly different subset of the other agents leading to a dynamic neighborhood topology. We implement the algorithm using the Player/Stage realistic robot simulator as well as on real KheperaIII robots using experimentally collected realistic data of ethanol gas concentration. Simulation …


Fractional Order Sliding Mode Control With Reaching Law Approach, MEHMET ÖNDER EFE 2010 TÜBİTAK

Fractional Order Sliding Mode Control With Reaching Law Approach, Mehmet Önder Efe

Turkish Journal of Electrical Engineering and Computer Sciences

Fractional order sliding mode control is studied in this paper. The control objectives are achieved by adopting the reaching law approach of sliding mode control. The main contribution of this work is to show that the philosophy of integer order sliding mode control is valid also for the systems represented by fractional order operators. A sufficient condition and its implications for stability are given. Matched and unmatched uncertainties are studied. The attractor nature of the switching manifold is analyzed together with a stable sliding subspace design condition. The claims are justified through a set of simulations and the results obtained …


A Model Based Nonlinear Adaptive Controller For The Passive Bilateral Telerobotic System, UFUK ÖZBAY, ERKAN ZERGEROĞLU, İLYAS KANDEMİR 2010 TÜBİTAK

A Model Based Nonlinear Adaptive Controller For The Passive Bilateral Telerobotic System, Ufuk Özbay, Erkan Zergeroğlu, İlyas Kandemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

IIn this paper, we propose a new adaptive controller scheme for the bilateral telerobotic/teleoperation systems. The proposed controller achieves asymptotic tracking despite the parametric uncertainties associated with both master and slave robots while ensuring the passivity of the closed loop system. Extensive simulation studies are presented to illustrate the feasibility and efficiency of the proposed adaptive controller.


A Novel Algorithm For Sensorless Motion Control Of Flexible Structures, ISLAM SHOUKRY MOHAMMED KHALIL, EMRAH DENİZ KUNT, ASIF SABANOVIC 2010 TÜBİTAK

A Novel Algorithm For Sensorless Motion Control Of Flexible Structures, Islam Shoukry Mohammed Khalil, Emrah Deni̇z Kunt, Asif Sabanovic

Turkish Journal of Electrical Engineering and Computer Sciences

This article demonstrates the validity of using an actuator as a single platform for measurements during a motion control assignment of flexible systems kept free from any kind of measurement. System acceleration level dynamics, parameters and interaction forces with the environment are coupled in an incident reaction torque that naturally rises when a flexible system is subjected to an action imposed by an attached actuator to the system. This work attempts to decouple each of the system parameters out of the incident coupled reaction torque at the interface point of the actuator with the flexible system by way of measurements …


Modeling And Control Of Flow Problems By Adaptation-Based Linear Parameter Varying Models, COŞKU KASNAKOĞLU 2010 TÜBİTAK

Modeling And Control Of Flow Problems By Adaptation-Based Linear Parameter Varying Models, Coşku Kasnakoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a systematic modeling and control approach for flow problems is considered. A nonlinear Galerkin model is obtained from the partial differential equations (PDEs) describing the flow; and a Linear Parameter Varying (LPV) model is constructed to approximate the Galerkin model, where the parameter variation of the LPV model is controller by an adaptation mechanism. The LPV model is then treated as a surrogate on which the control design is carried out, where the parameter variations provide a range of uncertainty in which the control design must perform satisfactorily. It is shown that if certain conditions are met, …


Simultaneous Rotor And Stator Resistance Estimation Of Squirrel Cage Induction Machine With A Single Extended Kalman Filter, EŞREF EMRE ÖZSOY, METİN GÖKAŞAN, OVSANNA SETA ESTRADA 2010 TÜBİTAK

Simultaneous Rotor And Stator Resistance Estimation Of Squirrel Cage Induction Machine With A Single Extended Kalman Filter, Eşref Emre Özsoy, Meti̇n Gökaşan, Ovsanna Seta Estrada

Turkish Journal of Electrical Engineering and Computer Sciences

Accurate knowledge of rotor and stator resistance variations in a squirrel-cage induction motor (SCIM) is crucial for the performance of sensorless control of SCIM over a wide range of speeds. This study seeks to address this issue with a single Extended Kalman Filter (EKF) based solution, which is also known to have accuracy limitations when a high number of parameters/states are estimated with a limited number of inputs. To this aim, different from the author's previous approach in operating several EKFs in an alternating manner (the so-called braided EKF), an 8^{th}-order EKF is implemented in this study to test its …


Precise Position Control Using Shape Memory Alloy Wires, BURCU DÖNMEZ, BÜLENT ÖZKAN, FEVZİ SUAT KADIOĞLU 2010 TÜBİTAK

Precise Position Control Using Shape Memory Alloy Wires, Burcu Dönmez, Bülent Özkan, Fevzi̇ Suat Kadioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Shape memory alloys (SMAs) are active metallic ``smart'' materials used as actuators and sensors in high technology smart systems [1]. The term shape memory refers to ability of certain materials to ``remember'' a shape, even after rather severe deformations: once deformed at low temperatures, these materials will stay deformed until heated, whereupon they will return to their original, pre-deformed ``learned'' shape [2]. This property can be used to generate motion and/or force in electromechanical devices and micro-machines. However, the accuracy of SMA actuators is severely limited by their highly nonlinear stimulus-response characteristics. In this work, modeling, simulation, and experimental efforts …


Design And Evaluation Of A Linear Switched Reluctance Actuator For Positioning Tasks, ANTÓNIO ESPÍRITO SANTO, ROSÁRIO CALADO, CARLOS CABRITA 2010 TÜBİTAK

Design And Evaluation Of A Linear Switched Reluctance Actuator For Positioning Tasks, António Espírito Santo, Rosário Calado, Carlos Cabrita

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the development of a new linear switched reluctance actuator and confirms its applicability to perform positioning tasks. After the explanation of the actuator working principle and the presentation of its electromechanical topology, an analysis is accomplished using a finite elements tool. Based on the theoretical results, an experimental prototype that can develop 150 N was constructed. Its behaviour is observed under two different control methods implemented with microcontrollers. Initially, position is controlled applying a single pulse-driving scheme. Meanwhile, significant improvements are obtained with the introduction of a sliding-mode controller, allowing movements with 1 mm of resolution.


Usage Of Spline Interpolation In Catheter-Based Cardiac Mapping, BÜLENT YILMAZ, UĞUR CUNEDİOĞLU, ENGİN BAYSOY 2010 TÜBİTAK

Usage Of Spline Interpolation In Catheter-Based Cardiac Mapping, Bülent Yilmaz, Uğur Cunedi̇oğlu, Engi̇n Baysoy

Turkish Journal of Electrical Engineering and Computer Sciences

Due to their minimal invasiveness catheters are highly preferred in cardiac mapping techniques used in the source localization of rhythm disturbances in the heart. In cardiac mapping, standard steerable catheters and multielectrode basket catheters are the two alternatives for the characterization of the underlying tissue on the inner (endocardium) and outer (epicardium) surfaces of the heart. As with any discrete sampling technique, an important question for catheter-based cardiac mapping is how to determine values at locations from which direct measurements are not available. Interpolation is the most common approach for providing values at unmeasured sites using the available measurements. In …


A Second Order Approximation To Reduce The Complexity Of Ldpc Decoders Based On Gallager's Approach, AYKUT KALAYCIOĞLU, OKTAY ÜRETEN, H. GÖKHAN İLK 2010 TÜBİTAK

A Second Order Approximation To Reduce The Complexity Of Ldpc Decoders Based On Gallager's Approach, Aykut Kalaycioğlu, Oktay Üreten, H. Gökhan İlk

Turkish Journal of Electrical Engineering and Computer Sciences

A piece-wise second order approximation to the f (x) = -log [tanh (x/2)] function is proposed to reduce the computational complexity of LDPC decoder's utilizing Log-Likelihood Ratio Belief Propagation (LLR-BP) algorithm based on Gallager's approach. Simulation results show that the proposed low complexity approximation doesn't cause BER performance degradation.


Performance Analysis Of Swarm Optimization Approaches For The Generalized Assignment Problem In Multi-Target Tracking Applications, ALİ ÖNDER BOZDOĞAN, ASIM EGEMEN YILMAZ, MURAT EFE 2010 TÜBİTAK

Performance Analysis Of Swarm Optimization Approaches For The Generalized Assignment Problem In Multi-Target Tracking Applications, Ali̇ Önder Bozdoğan, Asim Egemen Yilmaz, Murat Efe

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to investigate the suitability of selected swarm optimization algorithms to the generalized assignment problem as encountered in multi-target tracking applications. For this purpose, we have tested variants of particle swarm optimization and ant colony optimization algorithms to solve the 2D generalized assignment problem with simulated dense and sparse measurement/track matrices and compared their performance to that of the auction algorithm. We observed that, although with some modification swarm optimization algorithms provide improvement in terms of speed, they still fall behind the auction algorithm in finding the optimum solution to the problem. Among the investigated …


Fuzzy Adaptive Neural Network Approach To Path Loss Prediction In Urban Areas At Gsm-900 Band, TÜRKAN ERBAY DALKILIÇ, BERNA YEŞİM HANCI, AYŞEN APAYDIN 2010 TÜBİTAK

Fuzzy Adaptive Neural Network Approach To Path Loss Prediction In Urban Areas At Gsm-900 Band, Türkan Erbay Dalkiliç, Berna Yeşi̇m Hanci, Ayşen Apaydin

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the results of the Adaptive-Network Based Fuzzy Inference System (ANFIS) for the prediction of path loss in a specific urban environment. A new algorithm based ANFIS for tuning the path loss model is introduced in this work. The performance of the path loss model which is obtained from proposed algorithm is compared to the Bertoni-Walfisch model, which is one of the best studied for propagation analysis involving buildings. This comparison is based on the mean square error between predicted and measured values. According to the indicated error criterion, the errors related to the predictions that are obtained …


Behaviors Of Real-Time Schedulers Under Resource Modification And A Steady Scheme With Bounded Utilization, REFİK SAMET, ORHAN FİKRET DUMAN 2010 TÜBİTAK

Behaviors Of Real-Time Schedulers Under Resource Modification And A Steady Scheme With Bounded Utilization, Refi̇k Samet, Orhan Fi̇kret Duman

Turkish Journal of Electrical Engineering and Computer Sciences

In this article we present an analysis for task models having random resource needs and different arrival patterns. In hard real-time environments like avionic systems or nuclear reactors, the inputs to the system are obtained from real world by using sensors. And it is highly possible for a task to have different resource needs for each period according to these changing conditions of real world. We made an analysis of schedulers for task models having random resources in each period. Since feasibility tests for usual task models are just limited to some specific schedulers and arrival patterns, we made our …


An Approach Based On Particle Swarm Computation To Study The Nanoscale Dg Mosfet-Based Circuits, FAYACL DJEFFAL, TOUFIK BENDIB, REDHA BENZID, ABDELHAMID BENHAYA 2010 TÜBİTAK

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

Turkish Journal of Electrical Engineering and Computer Sciences

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


Utilizing The Technology Acceptance Model To Assess The Employee Adoption Of Information Systems Security Measures, Cynthia M. Jones, Richard V. McCarthy, Leila Halawi, Bahaudin Mujtaba 2010 Nova Southeastern University

Utilizing The Technology Acceptance Model To Assess The Employee Adoption Of Information Systems Security Measures, Cynthia M. Jones, Richard V. Mccarthy, Leila Halawi, Bahaudin Mujtaba

Publications

In this study, the factors that affect employee acceptance of information systems security measures were examined by extending the Technology Acceptance Model. Partial least squares structural equation modeling was applied to examine these factors. 174 valid responses from employees from companies in various industry segments in the United States and Canada were analyzed. The results of the statistical analysis indicate that subjective norm moderated by management support showed the strongest effect on intention to use information systems security measures.


Forensic Analysis Of A Playstation 3 Console, Scott Conrad, Greg Dorn, Philip Craiger 2010 University of Central Florida

Forensic Analysis Of A Playstation 3 Console, Scott Conrad, Greg Dorn, Philip Craiger

Publications

The Sony PlayStation 3 (PS3) is a powerful gaming console that supports Internet-related activities, local file storage and the playing of Blu-ray movies. The PS3 also allows users to partition and install a secondary operating system on the hard drive. This “desktop-like” functionality along with the encryption of the primary hard drive containing the gaming software raises significant issues related to the forensic analysis of PS3 systems. This paper discusses the PS3 architecture and behavior, and provides recommendations for conducting forensic investigations of PS3 systems.


A New Framework For Qos Provisioning In Wireless Lans Using The P-Persistent Mac Protocol, Kiran Babu Anna 2010 University of Central Florida

A New Framework For Qos Provisioning In Wireless Lans Using The P-Persistent Mac Protocol, Kiran Babu Anna

Electronic Theses and Dissertations

The support of multimedia traffic over IEEE 802.11 wireless local area networks (WLANs) has recently received considerable attention. This dissertation has proposed a new framework that provides efficient channel access, service differentiation and statistical QoS guarantees in the enhanced distributed channel access (EDCA) protocol of IEEE 802.11e. In the first part of the dissertation, the new framework to provide QoS support in IEEE 802.11e is presented. The framework uses three independent components, namely, a core MAC layer, a scheduler, and an admission control. The core MAC layer concentrates on the channel access mechanism to improve the overall system efficiency. The …


Cloud Security Requirements Analysis And Security Policy Development Using A High-Order Object-Oriented Modeling Technique, Kenneth Kofi Fletcher 2010 Missouri University of Science and Technology

Cloud Security Requirements Analysis And Security Policy Development Using A High-Order Object-Oriented Modeling Technique, Kenneth Kofi Fletcher

Masters Theses

"Security continues to be a major challenge for cloud computing, and it is one that must be addressed if cloud computing is to be fully accepted. Most technological means of securing non-cloud computing systems can be either applied directly or modified to secure a cloud; however, no integrated model-based methodology is yet available to analyze cloud security requirements and develop policy to deal with both internal and external security challenges. This work proposes just such a methodology and demonstrates its application with specific cases. Cloud assets are represented by high order object models, and misuse cases together with malactivity swimlane …


Digital Commons powered by bepress