Adaptive Feedback Control For Linear Singular Systems,
2014
TÜBİTAK
Adaptive Feedback Control For Linear Singular Systems, Azita Azarfar, Heydar Toossian Shandiz, Masoud Shafiee
Turkish Journal of Electrical Engineering and Computer Sciences
An adaptive state feedback control approach for linear descriptor (or singular) systems is investigated in this paper, which makes the closed-loop dynamics of this class of systems regular, impulse-free, and stable. The proposed adaptive method is based on the Lyapunov theorem to ensure the admissibility of the descriptor system and it also provides the state tracking with the desired reference trajectory. First, a control law is generated to stabilize the equilibrium point of origin, and, after that, the method is extended to a state tracking controller. The presented controller not only gets the stable output tracking asymptotically but is also …
A Web Laboratory Using Matlab Builder Ne For Computer Image Processing,
2014
TÜBİTAK
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,
2014
TÜBİTAK
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 …
A New Approach In The Evaluation Of Hospital Information Systems,
2014
TÜBİTAK
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 …
Concurrently Attuned Design Of A Wadc-Based Upfc Psdc And Multiinput Pss For Improving Power System Dynamic Performance,
2014
TÜBİTAK
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,
2014
TÜBİTAK
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 …
Markovian Approach Applied To Reliability Modeling Of A Wind Farm,
2014
TÜBİTAK
Markovian Approach Applied To Reliability Modeling Of A Wind Farm, Mazaher Hajibashi, Akbar Ebrahimi
Turkish Journal of Electrical Engineering and Computer Sciences
The exploitation of wind energy as a resource for generating electricity is going to make a leap forward. Large-scale wind farms (WFs) will be engaged with power systems in the near future and this will cause changes in the supply pattern. Wind speed has an intermittent behavior and the output power of a WF is highly variable, consistent with this fact. The Markov process could consider this characteristic of wind speed using the state transition rate probability matrix, an issue that is neglected when a probability distribution function is established to model the wind speed data. The adequacy indices of …
Design And Implementation Of A Programmable High-Voltage Impulse Measurement System,
2014
TÜBİTAK
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, …
Design Of A Double-Stator Linear Switched Reluctance Motor For Shunting Railway Channels,
2014
TÜBİTAK
Design Of A Double-Stator Linear Switched Reluctance Motor For Shunting Railway Channels, El Manaa Barhoumi, Mansour Hajji, Boujemaa Ben Salah
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the design and modeling of a double-stator linear switched reluctance motor for motorizing a railway channels' shunting system. The magnetic behavior of this actuator is nonlinear due to the saturation and nonlinear magnetization curves of the materials used in this actuator. For this reason, the electromagnetic quantities such as force, flux linkage, and inductance are calculated with the finite element method using the Maxwell tool. The obtained results are presented and discussed. In order to elaborate some control strategies, a new model for the proposed actuator, based on the flux and force characteristics, is validated by the …
A Novel Approach Based On Reliability Sensitivity Analysis To Allocate Protective Devices,
2014
TÜBİTAK
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 …
Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter,
2014
TÜBİTAK
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,
2014
TÜBİTAK
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,
2014
TÜBİTAK
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 …
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,
2014
TÜBİTAK
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?,
2014
TÜBİTAK
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,
2014
TÜBİTAK
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. …
Privacy Preserving In Association Rules Using A Genetic Algorithm,
2014
TÜBİTAK
Privacy Preserving In Association Rules Using A Genetic Algorithm, Rahat Ali Shah, Sohail Asghar
Turkish Journal of Electrical Engineering and Computer Sciences
Association rule mining is one of the data mining techniques used to extract hidden knowledge from large datasets. This hidden knowledge contains useful and confidential information that users want to keep private from the public. Similarly, privacy preserving data mining techniques are used to preserve such confidential information or restrictive patterns from unauthorized access. The pattern can be represented in the form of a frequent itemset or association rule. Furthermore, a rule or pattern is marked as sensitive if its disclosure risk is above a given threshold. Numerous techniques have been used to hide sensitive association rules by performing some …
Feature Selection On Single-Lead Ecg For Obstructive Sleep Apnea Diagnosis,
2014
TÜBİTAK
Feature Selection On Single-Lead Ecg For Obstructive Sleep Apnea Diagnosis, Hüseyi̇n Gürüler, Mesut Şahi̇n, Abdullah Feri̇koğlu
Turkish Journal of Electrical Engineering and Computer Sciences
Many articles that appeared in the literature agreed upon the feasibility of diagnosing obstructive sleep apnea (OSA) with a single-lead electrocardiogram. Although high accuracies have been achieved in detection of apneic episodes and classification into apnea/hypopnea, there has not been a consensus on the best method of selecting the feature parameters. This study presents a classification scheme for OSA using common features belonging to the time domain, frequency domain, and nonlinear calculations of heart rate variability analysis, and then proposes a method of feature selection based on correlation matrices (CMs). The results show that the CMs can be utilized in …
Vessel Segmentation In Mri Using A Variational Image Subtraction Approach,
2014
TÜBİTAK
Vessel Segmentation In Mri Using A Variational Image Subtraction Approach, Ayşe Nurdan Saran, Fati̇h Nar, Murat Saran
Turkish Journal of Electrical Engineering and Computer Sciences
Vessel segmentation is important for many clinical applications, such as the diagnosis of vascular diseases, the planning of surgery, or the monitoring of the progress of disease. Although various approaches have been proposed to segment vessel structures from 3-dimensional medical images, to the best of our knowledge, there has been no known technique that uses magnetic resonance imaging (MRI) as prior information within the vessel segmentation of magnetic resonance angiography (MRA) or magnetic resonance venography (MRV) images. In this study, we propose a novel method that uses MRI images as an atlas, assuming that the patient has an MRI image …
