Optimized Operation And Maintenance Costs To Improve System Reliability By Decreasing The Failure Rate Of Distribution Lines,
2013
TÜBİTAK
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 …
Design Of Information Retrieval Experiments: The Sufficient Topic Set Size For Providing An Adequate Level Of Confidence,
2013
TÜBİTAK
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 …
A Novel Dynamic Bandwidth Selection Method For Thinning Noisy Point Clouds,
2013
TÜBİTAK
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 …
Compact Microstrip Antenna With Metamaterial For Wideband Applications,
2013
TÜBİTAK
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.
Optimal Placement And Sizing Of Distributed Generations In Distribution Systems For Minimizing Losses And Thd_V Using Evolutionary Programming, Aida Fazliana Abdul Kadir, Azah Mohamed, Hussain Shareef, Mohd Zamri Che Wanik
Turkish Journal of Electrical Engineering and Computer Sciences
Growing concerns over environmental impacts, improvement of the overall network conditions, and rebate programs offered by governments have led to an increase in the number of distributed generation (DG) units in commercial and domestic electric power production. However, a large number of DG units in a distribution system may sometimes contribute to high levels of harmonic distortion, even though the emission levels of the individual DG units comply with the harmonic standards. It is known that the nonoptimal size and nonoptimal placement of DG units may lead to high power losses, bad voltage profiles, and harmonic propagations. Therefore, this paper …
Multi-Objective Weighted Sum Approach Model Reduction By Routh-Pade Approximation Using Harmony Search,
2013
TÜBİTAK
Multi-Objective Weighted Sum Approach Model Reduction By Routh-Pade Approximation Using Harmony Search, Hasan Nasiri Soloklo, Malihe Maghfoori Farsangi
Turkish Journal of Electrical Engineering and Computer Sciences
A new weighted-sum multiobjective approach is investigated for order reduction based on Routh--Padé approximation, in which the harmony search algorithm is used to optimize the reduced-order model's parameters. In this method, apart from minimizing the errors between a set of subsequent time moments/Markov parameters of the system and those of the model, the error between the singular values of the reduced-order system and those of the original system is minimized. The Routh criterion is applied for specifying the stability conditions. The stability condition is then considered as a constraint in the optimization problem. To present the ability of the proposed …
Minimal Controller Synthesis Algorithms With Output Feedback And Their Generalization,
2013
TÜBİTAK
Minimal Controller Synthesis Algorithms With Output Feedback And Their Generalization, Ata Sevi̇nç
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes several improvements in the minimal controller synthesis algorithms, which were developed for a class of nonlinear systems with uncertainties. The major proposition is that only the output feedback is enough to control some nonlinear systems without an observer while the existing algorithms require the complete state feedback. Next, the extended version and the parameter identification technique of the minimal controller synthesis algorithm are combined in a single method estimating some more parameters for some known forms of nonlinearities. This is applicable with or without the improvement of removing the need for using the complete state feedback. It …
Negative Selection Algorithm For Dengue Outbreak Detection,
2013
TÜBİTAK
Negative Selection Algorithm For Dengue Outbreak Detection, Maryam Mousavi, Azuraliza Abu Bakar, Suhaila Zainudin, Zalizah Awang Long, Mazrura Sahani, Mohammadmahdi Vakilian
Turkish Journal of Electrical Engineering and Computer Sciences
Dengue is a critical communicable and vector-borne disease and is becoming a serious concern in Malaysia. It is important to have an early detection system that could provide immediate action, such as the control of dengue transmission at a specific location. However, the available strategy and action may give long-term effects to the community since inaccurate decision making or prediction may lead to other circumstances. Moreover, the need to have a system that can detect the outbreak in a reasonable amount of time is critical. In this study, a nature-inspired computing technique, the artificial immune system (AIS), is used for …
A Video-Based Eye Pupil Detection System For Diagnosing Bipolar Disorder,
2013
TÜBİTAK
A Video-Based Eye Pupil Detection System For Diagnosing Bipolar Disorder, Gökay Akinci, Edi̇z Polat, Orhan Murat Koçak
Turkish Journal of Electrical Engineering and Computer Sciences
Eye pupil detection systems have become increasingly popular in image processing and computer vision applications in medical systems. In this study, a video-based eye pupil detection system is developed for diagnosing bipolar disorder. Bipolar disorder is a condition in which people experience changes in cognitive processes and abilities, including reduced attentional and executive capabilities and impaired memory. In order to detect these abnormal behaviors, a number of neuropsychological tests are also designed to measure attentional and executive abilities. The system acquires the position and radius information of eye pupils in video sequences using an active contour snake model with an …
A Flexible Rule-Based Framework For Pilot Performance Analysis In Air Combat Simulation Systems,
2013
TÜBİTAK
A Flexible Rule-Based Framework For Pilot Performance Analysis In Air Combat Simulation Systems, Ömer Faruk Arar, Kürşat Ayan
Turkish Journal of Electrical Engineering and Computer Sciences
Air combat simulation systems (ACSSs) are developed to train fighter pilots (trainees) in a virtual combat environment. In general, an ACSS consists of the following stages: planning the scenario, training, flight analysis, and performance evaluation. In this paper, the details of the framework, which is developed to analyze and evaluate the performance of the trainees, is introduced. First, the evaluation criteria for the pilot performance are defined. Next, a dynamic pilot performance evaluation system is developed that can be controlled and modified by experienced instructor pilots (instructors/trainers) to define the performance criteria details using predefined evaluation parameters. The evaluation of …
Artificial Immunity-Based Induction Motor Bearing Fault Diagnosis,
2013
TÜBİTAK
Artificial Immunity-Based Induction Motor Bearing Fault Diagnosis, Hakan Çaliş, Abdülkadi̇r Çakir, Emre Dandil
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the artificial immunity of the negative selection algorithm is used for bearing fault detection. It is implemented in MATLAB-based graphical user interface software. The developed software uses amplitudes of the vibration signal in the time and frequency domains. Outer, inner, and ball defects in the bearings of the induction motor are detected by anomaly monitoring. The time instants of the fault occurrence and fault level are determined according to the number of activated detectors. Anomaly detection in the frequency domain is implemented by monitoring the fault indicator bearing frequencies and harmonics, calculated using the bearing dimensions and …
The Vortex Effect Of Francis Turbine In Electric Power Generation,
2013
TÜBİTAK
The Vortex Effect Of Francis Turbine In Electric Power Generation, Veli̇ Türkmenoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the vibration effects of a vortex that occurred in high-head Francis turbines and an alternator are examined. The vortex effect, which directly affects the efficiency and the quality of the energy, was tested at the DarÔøΩca-1 hydroelectric power plant (HPP) located in Ordu Province, Turkey. Formed by undissolved oxygen in the water, the vortex effect, which is parallel to the alternator load, causes tremendous vibration within the alternator and Francis turbine bearings. This problem, which has a direct negative effect on the alternator capacity, was solved by adding an air-admission system. In doing so, power production was …
A Practical Disturbance Generator To Test Performances Of Various Power Quality Mitigation Devices,
2013
TÜBİTAK
A Practical Disturbance Generator To Test Performances Of Various Power Quality Mitigation Devices, Ahmet Teke, Mehmet Emi̇n Meral, Mehmet Tümay, Mehmet Uğraş Cuma
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a practical thyristor-based 3-phase sag/swell/outage generator (disturbance generator) is designed to test various power quality mitigation devices (PQMDs), such as solid state transfer switch (SSTS), static voltage compensator (SVC), and uninterruptible power supply. The latest technological disturbance generators (DGs) and the proposed DG are comprehensively discussed and compared with focus on usefulness, economic aspects, and simplicity. The proposed DG is used for experimentally generating different fault conditions and testing a SSTS. The comparisons and analyses show that the proposed DG is an optimum and simple solution to generate sag, swell, unbalance, overvoltage, undervoltage, and outage to test …
Pc-Based Data Acquisition System For Plc-Controlled Linear Switched Reluctance Motor,
2013
TÜBİTAK
Pc-Based Data Acquisition System For Plc-Controlled Linear Switched Reluctance Motor, Mahi̇r Dursun, Semi̇h Özden
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a linear switched reluctance motor (LSRM) with 250 W, 6/4 poles, 3 phases, and 24 V was controlled with a programmable logic controller (PLC). Some parameters of the LSRM were set, and for PC monitoring, software developed by the authors was used. A serial port was used for communication between the PC and the PLC. The software was developed with Visual C#.Net 2008 for monitoring and controlling. This user interference allows for controlling of the motor's travelling distance with a running strategy. The first and second destination can be defined and the system provides that the motor …
Circulating Current Analysis Between Strands In Armature Winding Of A Turbo-Generator Using Analytical Model,
2013
TÜBİTAK
Circulating Current Analysis Between Strands In Armature Winding Of A Turbo-Generator Using Analytical Model, Karim Abbaszadeh, Farhad Rezaee Alam
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the circulating current analysis between strands is studied while considering the different transpositions in the active part and without considering the transposition in the end winding region. First, this analysis is done while only considering the slot region, and then the end winding region is added to the model. The model used for this analysis is a circuit model, including the resistance and inductance of the strands and their induced back-electromotive force (EMF). The back-EMF sources and inductances are calculated through a 2D finite element analysis (FEA) of the active part and a 3D FEA for the …
Composite Power System Adequacy Assessment Based On Postoptimal Analysis,
2013
TÜBİTAK
Composite Power System Adequacy Assessment Based On Postoptimal Analysis, Amir Safdarian, Mahmood Fotuhi-Firuzabad, Farrokh Aminifar
Turkish Journal of Electrical Engineering and Computer Sciences
The modeling and evaluation of enormous numbers of contingencies are the most challenging impediments associated with composite power system adequacy assessment, particularly for large-scale power systems. Optimal power flow (OPF) solution, as a widely common approach, is normally employed to model and analyze each individual contingency as an independent problem. However, mathematical representations associated with diverse states are slightly different in one or a few generating units, line outages, or trivial load variations. This inherent attribute brings a promising idea to speed up the contingency evaluation procedure. In this paper, postoptimal analysis (POA), as a well-recognized technique to attack a …
Modified Iterated Extended Kalman Particle Filter For Single Satellite Passive Tracking,
2013
TÜBİTAK
Modified Iterated Extended Kalman Particle Filter For Single Satellite Passive Tracking, Panlong Wu, Jianshou Kong, Yuming Bo
Turkish Journal of Electrical Engineering and Computer Sciences
Single satellite-to-satellite passive tracking techniques have great significance in space surveillance systems. A new passive modified iterated extended Kalman particle filter (MIEKPF) using bearings-only measurements in the Earth-Centered Inertial Coordinate System is proposed. The modified iterated extended Kalman filter (MIEKF), with a new maximum likelihood iteration termination criterion, is used to generate the proposal distribution of the MIEKPF. Moreover, a new measurement update equation of the MIEKF is derived by modifying the objective function of the Gauss--Newton iteration. The approximated second-order linearized state propagation equation, Jacobian matrix of state transfer, and measurement equations are derived in satellite 2-body movement. The …
The Development Of A Hardware- And Software-Based Simulation Platform For The Training Of Driver Candidates,
2013
TÜBİTAK
The Development Of A Hardware- And Software-Based Simulation Platform For The Training Of Driver Candidates, Abdullah Çavuşoğlu, İsmai̇l Kurnaz
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a traffic simulation system (TSS) to provide novice driver candidates with opportunities for training and testing has been developed. Autonomous vehicles that follow the flow of traffic in a microsimulation environment were prepared using a hierarchical concurrent state machine. Autonomous vehicles are skilled and have behavioral aspects such as tracking the lanes, following the vehicles, complying with traffic rules, decelerating, accelerating, and intersection crossings. These driver behaviors are parameterized to allow the autonomous agents to act while disregarding the rules (i.e. aggressive behaviors) or behaving normally. The TSS is operated in 3 different modes, namely the orientation, …
Spatiotemporal Model Checking Of Location And Mobility Related Security Policy Specifications,
2013
TÜBİTAK
Spatiotemporal Model Checking Of Location And Mobility Related Security Policy Specifications, Devri̇m Ünal, Mehmet Ufuk Çağlayan
Turkish Journal of Electrical Engineering and Computer Sciences
For the formal verification of security in mobile networks, a requirement is that security policies associated with mobility and location constraints are formally specified and verified. For the formal specification and verification of security policies, formal methods ensure that a given network configuration that includes certain network elements satisfies a given security policy. A process calculus based approach is presented, where ambient calculus is used for formal specification of security policies and ambient logic is used for formal representation of mobility and location constraints. A spatiotemporal model checking algorithm is presented for the model checking of formal specifications in ambient …
A Time--Memory Trade-Off Approach For The Solution Of Nonlinear Equation Systems,
2013
TÜBİTAK
A Time--Memory Trade-Off Approach For The Solution Of Nonlinear Equation Systems, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Muhammed Oğuzhan Külekci̇
Turkish Journal of Electrical Engineering and Computer Sciences
We propose a memory-based method for the solution of a specific type of nonlinear equation systems. We observe that when the equations in a system can be separated into 2 parts, where each subset contains fewer parameters than the whole set of equations, the system can be solved faster with a preprocessing phase. We show that reduced rounds of AES produce such a system under a chosen plaintext scenario. This observation enables us to solve that system within a practically applicable complexity of 2^{37} operations where a brute force approach requires 2^{72} trials. The method can be used for the …
