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Full-Text Articles in Computer Engineering

Real-Time Implementation Of An Amplitude-Locked Loop: A Validation On The Dspace Ds1006-Based Platform, Jora Mangala Gonda, Sumam Sarah Jan 2013

Real-Time Implementation Of An Amplitude-Locked Loop: A Validation On The Dspace Ds1006-Based Platform, Jora Mangala Gonda, Sumam Sarah

Turkish Journal of Electrical Engineering and Computer Sciences

The extraction of harmonics and/or the fundamental from a distorted waveform is an important process in the implementation of custom-power devices. Several schemes towards this have been proposed in the past. Among these, the algorithms based on synchronous (with respect to the supply voltages) extraction (both in phase and amplitude) have certain established advantages over the others. Amplitude-locked loops (ALLs) have been in use in signal-communication systems but are limited to sinusoidal inputs. There is a need for fast and rugged algorithms to synchronously extract harmonics and/or the fundamental from a distorted waveform in many power system applications. In this …


Low-Cost And Power-Efficient Thread Collision Detection Scheme For Shared Caches In A Real-Time Multithreaded Embedded Processor, Emre Özer Jan 2013

Low-Cost And Power-Efficient Thread Collision Detection Scheme For Shared Caches In A Real-Time Multithreaded Embedded Processor, Emre Özer

Turkish Journal of Electrical Engineering and Computer Sciences

This paper addresses an important issue in a real-time multithreaded embedded processor where several active hardware threads share the critical resources such as caches in the processor. Thread interferences or collisions could lead to severe performance degradations on the real-time threads. Although the cache interference issue on real-time multithreaded processors has been studied before, no cost-effective and simpler hardware solutions were proposed to maintain the single thread performance of the real-time thread while still letting the low-priority threads progress. A novel technique called collision tag is proposed to address these issues. Progressively, the collision tag scheme can be reduced into …


Microelectronic Interconnect Modeling With A Periodical Lumped Rlc-Network, Blaise Ravelo Jan 2013

Microelectronic Interconnect Modeling With A Periodical Lumped Rlc-Network, Blaise Ravelo

Turkish Journal of Electrical Engineering and Computer Sciences

A modeling of high-speed microelectronic interconnections based on periodical resistor-inductor-capacitor (RLC) cells is presented in this paper. A theoretical investigation enabling one to determine the interconnect structure transfer function is established. The proposed theory is based on the use of the ABCD matrix product of elementary cells, constituting the whole interconnect structure. After extracting the constituting lumped elements R, L, and C, which model the considered interconnection, examples of the numerical validations were proposed, both in the frequency and time domains. It was demonstrated that by considering a structure comprised of 10 elementary segments in cascade, S-parameters and time-domain results …


Investigation Of The Telluric Effects Arising Along The Cathodically Protected Natural Gas Pipeline Between Karadeniz Ereğli And Düzce, Bi̇lal Demi̇rel, Hayri̇ Yalçin Jan 2013

Investigation Of The Telluric Effects Arising Along The Cathodically Protected Natural Gas Pipeline Between Karadeniz Ereğli And Düzce, Bi̇lal Demi̇rel, Hayri̇ Yalçin

Turkish Journal of Electrical Engineering and Computer Sciences

Cathodic protection is one of the most widely used applications for protecting underground and submarine metallic structures from corrosion. This method is based on providing the electrons, which metallic structures lose as a result of electrolytic reaction, by the cathodic protection system. However, from time to time, it may be possible that there is some unwanted interference input into the metallic structure in such applications. This study is aimed at ascertaining the existence, arising frequency, and magnitude of an interference called the telluric effect that is going in and out of the natural gas pipeline between Düzce and Karadeniz Ereğli …


An Automated Signal Alignment Algorithm Based On Dynamic Time Warping For Capillary Electrophoresis Data, Fethullah Karabi̇ber Jan 2013

An Automated Signal Alignment Algorithm Based On Dynamic Time Warping For Capillary Electrophoresis Data, Fethullah Karabi̇ber

Turkish Journal of Electrical Engineering and Computer Sciences

Correcting the retention time variation and measuring the similarity of time series is one of the most popular challenges in the area of analyzing capillary electrophoresis (CE) data. In this study, an automated signal alignment method is proposed by modifying the dynamic time warping (DTW) approach to align the time-series data. Preprocessing tools and further optimizations were developed to increase the performance of the algorithm. As a demonstrative case study, the developed algorithm is applied to the analysis of CE data from a selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) evaluation of the RNA secondary structure. The time-shift problem …


A New Multiobjective Fuzzy Shuffled Frog-Leaping Algorithm For Optimal Reconfiguration Of Radial Distribution Systems In The Presence Of Reactive Power Compensators, Hossein Dehghan Dehnavi, Saeid Esmaeili Jan 2013

A New Multiobjective Fuzzy Shuffled Frog-Leaping Algorithm For Optimal Reconfiguration Of Radial Distribution Systems In The Presence Of Reactive Power Compensators, Hossein Dehghan Dehnavi, Saeid Esmaeili

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach for the optimal reconfiguration of radial distribution systems in the presence of reactive power compensators (RPCs). The proposed method is based on the simultaneous reconfiguration and RPC allocation for the mitigation of losses, equalizing the feeder load balancing as well as improving the voltage profile in power distribution networks. In this paper, the compensators are the capacitor bank and distribution static compensator, which is a type of distribution flexible alternating current transmission system device representative of conventional and modern RPCs. In this regard, the optimal states of the distribution system tie switches are determined …


Biogeography-Based Optimization For Voltage Stability Improvement And Reactive Reserve Management, Subramanian Annamalai, Ravi Govinthabamy Jan 2013

Biogeography-Based Optimization For Voltage Stability Improvement And Reactive Reserve Management, Subramanian Annamalai, Ravi Govinthabamy

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a biogeography-based optimization algorithm to enhance the voltage stability of a power system. It computes the optimal quantity of reactive power support with a view to place the static VAR compensator at the most appropriate nodes. The scheme inflicts an effective management of VAR resources in the process of improving the voltage profile and reducing the network losses. It includes the results of IEEE 30-node system to illustrate the feasibility of the approach.


On-Line Self-Learning Pid Controller Design Of Sssc Using Self-Recurrent Wavelet Neural Networks, Soheil Ganjefar, Mojtaba Alizadeh Jan 2013

On-Line Self-Learning Pid Controller Design Of Sssc Using Self-Recurrent Wavelet Neural Networks, Soheil Ganjefar, Mojtaba Alizadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Conventionally, FACTS devices employ a proportional-integral (PI) controller as a supplementary controller. However, the conventional PI controller has many disadvantages. The present paper aims to propose an on-line self-learning PI-derivative (PID) controller design of a static synchronous series compensator for power system stability enhancement and to overcome the PI controller problems. Unlike the PI controllers, the proposed PID controller has a local nature because of its powerful adaption process, which is based on the back-propagation (BP) algorithm that is carried out through an adaptive self-recurrent wavelet neural network identifier (ASRWNNI). In fact, the PID controller parameters are updated in on-line …


A Computer-Aided Diagnosis System For Breast Cancer Detection By Using A Curvelet Transform, Nebi̇ Gedi̇k, Ayten Atasoy Jan 2013

A Computer-Aided Diagnosis System For Breast Cancer Detection By Using A Curvelet Transform, Nebi̇ Gedi̇k, Ayten Atasoy

Turkish Journal of Electrical Engineering and Computer Sciences

The most common type of cancer among women worldwide is breast cancer. Early detection of breast cancer is very important to reduce the fatality rate. For the hundreds of mammographic images scanned by a radiologist, only a few are cancerous. While detecting abnormalities, some of them may be missed, as the detection of suspicious and abnormal images is a recurrent mission that causes fatigue and eyestrain. In this paper, a computer-aided diagnosis system using the curvelet transform (CT) algorithm is proposed for interpreting mammograms to improve the decision making. The purpose of this study is to develop a method for …


Role Of Energy Management In Hybrid Renewable Energy Systems: Case Study-Based Analysis Considering Varying Seasonal Conditions, Recep Yumurtaci Jan 2013

Role Of Energy Management In Hybrid Renewable Energy Systems: Case Study-Based Analysis Considering Varying Seasonal Conditions, Recep Yumurtaci

Turkish Journal of Electrical Engineering and Computer Sciences

The recent popularity of alternative energy technologies is mainly promoted by the increasing awareness of environmental concerns as well as the economic impacts of the depleting fossil fuel reserves. Among several alternative technologies, wind- and solar-based energy have been given specific importance with government-based support for providing a cost-effective structure to realize better penetration of such environmentally friendly sources in the energy market. Even these sources are advantageous over the conventional means of energy production from many aspects, a main drawback being the total dependence on the meteorological conditions (wind speed, solar radiation, temperature, etc.) of the wind and solar …


Opf-Based Reactive Power Planning And Voltage Stability Limit Improvement Under Single Line Outage Contingency Condition Through Evolutionary Algorithms, Sakthivel Padaiyatchi, Mary Daniel Jan 2013

Opf-Based Reactive Power Planning And Voltage Stability Limit Improvement Under Single Line Outage Contingency Condition Through Evolutionary Algorithms, Sakthivel Padaiyatchi, Mary Daniel

Turkish Journal of Electrical Engineering and Computer Sciences

Reactive power planning is vital for maintaining the voltage stability of power systems and evolutionary algorithms are highly useful for achieving this task. This paper compares the effectiveness of the differential evolution (DE) and evolutionary programming (EP) algorithms in optimizing the reactive power planning of power systems under line outage contingency conditions. DE is efficient in exploration through the search space of the problem, while EP is simple and easy to implement. The low cost but fast response thyristor-controlled series capacitor (TCSC) flexible alternating current transmission system (FACTS) device is incorporated to control the power flows. The optimal settings of …


Implementation Of An Ac Model For Transmission Expansion Planning Considering Reliability Constraints, Amin Mahmoudabad, Masoud Rashidinejad, Majid Zeinaddini-Meymand, Mohsen Rahmani Jan 2013

Implementation Of An Ac Model For Transmission Expansion Planning Considering Reliability Constraints, Amin Mahmoudabad, Masoud Rashidinejad, Majid Zeinaddini-Meymand, Mohsen Rahmani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a hybrid heuristic methodology that employs fuzzy logic for solving the AC transmission network expansion planning (AC-TEP) problem is presented. An enhanced constructive heuristic algorithm aimed at obtaining a significant quality solution for such complicated problems considering contingency is proposed. In order to indicate the severity of the contingency, 2 performance indices, namely the line flow performance index and voltage performance index, are calculated. An interior point method is applied as a nonlinear programming solver to handle such nonconvex optimization problems, while the objective function includes the costs of the new transmission lines as well as the …


Shape Control Of Cyclic Networks In Multirobot Formations, Tolga Eren Jan 2013

Shape Control Of Cyclic Networks In Multirobot Formations, Tolga Eren

Turkish Journal of Electrical Engineering and Computer Sciences

The first part of this paper examines cycles at the network level of sensing and control architectures that are needed to maintain the shape of a multiagent formation in 2-dimensional space, while the formation moves as a cohesive whole. The key tools used in the paper are rigidity theory and graph theory. The second part of the paper focuses on the planner level and controller level of the architecture by designing the fuzzy planner and fuzzy controller of individual agents. This permits the decomposition of the complex coordination problem into a series of smaller ones. The fuzzy planner and the …