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Full-Text Articles in Physical Sciences and Mathematics

Fault-Tolerant Control Of A Pmsg-Based Wind Turbine Based On Parallelinterleaved Converters, Mohamed Abbes Jan 2019

Fault-Tolerant Control Of A Pmsg-Based Wind Turbine Based On Parallelinterleaved Converters, Mohamed Abbes

Turkish Journal of Electrical Engineering and Computer Sciences

Lowering the cost of wind energy has been one of the main objectives of the wind industry in the past years. To achieve this objective, considerable research efforts have been made to improve the availability of wind turbines. Recent statistical analyses have shown that frequency converters are among the most frequently failing components for variable speed wind systems. Therefore, several configurations were proposed in the literature to improve the availability of these generating devices. These configurations are mainly based on the redundancy of power converters (active and standby) or the converter bypass technique. However, for the special case of PMSG-based …


Particle Swarm Optimization Approach To Optimal Design Of An Afpm Tractionmachine For Different Driving Conditions, Naghi Rostami Jan 2019

Particle Swarm Optimization Approach To Optimal Design Of An Afpm Tractionmachine For Different Driving Conditions, Naghi Rostami

Turkish Journal of Electrical Engineering and Computer Sciences

Axial flux permanent magnet (AFPM) machines can be employed as the traction motor of electric vehicles due to their high torque capability, high efficiency, modular and compact construction, and capability of integration with other mechanical components in integrated systems. Besides, the system efficiency can be further improved by optimal design of the selected electric machine. In this paper, an AFPM machine is optimized against two well-known driving cycles called the New European Drive Cycle (NEDC) and US06 and the influence of the driving cycle on the obtained machine parameters is evaluated. US06 is the more demanding driving cycle and thus …


Towards Wearable Blood Pressure Measurement Systems From Biosignals: A Review, Ümi̇t Şentürk, Kemal Polat, İbrahi̇m Yücedağ Jan 2019

Towards Wearable Blood Pressure Measurement Systems From Biosignals: A Review, Ümi̇t Şentürk, Kemal Polat, İbrahi̇m Yücedağ

Turkish Journal of Electrical Engineering and Computer Sciences

Blood pressure is the pressure by the blood to the vein wall. High blood pressure, which is called silent death, is the cause of nearly 13 % of mortality all over the world. Blood pressure is not only measured in the medical environment, but the blood pressure measurement is also a need for people in their daily life. Blood pressure estimation systems with low error rates have been developed besides the new technologies and algorithms. Blood pressure measurements are differentiated as invasive blood pressure (IBP) measurement and noninvasive blood pressure (NIBP) measurement methods. Although IBP measurement provides the most accurate …


Sparsity-Based Three-Dimensional Image Reconstruction For Near-Field Mimo Radar Imaging, Fi̇gen S. Oktem Jan 2019

Sparsity-Based Three-Dimensional Image Reconstruction For Near-Field Mimo Radar Imaging, Fi̇gen S. Oktem

Turkish Journal of Electrical Engineering and Computer Sciences

Near-field multiple-input multiple-output (MIMO) radar imaging systems are of interest in diverse fields such as medicine, through-wall imaging, airport security, concealed weapon detection, and surveillance. The successful operation of these radar imaging systems highly depends on the quality of the images reconstructed from radar data. Since the underlying scenes can be typically represented sparsely in some transform domain, sparsity priors can effectively regularize the image formation problem and hence enable high-quality reconstructions. In this paper, we develop an efficient three-dimensional image reconstruction method that exploits sparsity in near-field MIMO radar imaging. Sparsity is enforced using total variation regularization, and the …


Softswitch: A Centralized Honeypot-Based Security Approach Using Software-Defined Switching For Secure Management Of Vlan Networks, Muhammet Baykara, Resul Daş Jan 2019

Softswitch: A Centralized Honeypot-Based Security Approach Using Software-Defined Switching For Secure Management Of Vlan Networks, Muhammet Baykara, Resul Daş

Turkish Journal of Electrical Engineering and Computer Sciences

Honeypot systems are traps for intruders which simulate real systems such as web, application, and database servers used in information systems. Using these systems, unauthorized and malicious access can be efficiently detected. Honeypot is an entity which acts as a source of valued information and its behavior can be monitored. The inability or difficulty of intrusion detection is a serious security problem in networks including virtual local area network (VLAN). According to the literature, the use of honeypots for intrusion detection and prevention in networks including VLAN is strongly recommended. In this paper, in order to provide security and to …


Symptom-Aware Hybrid Fault Diagnosis Algorithm In The Network Virtualization Environment, Yuze Su, Xiangru Meng, Xiaoyang Han, Qiaoyan Kang Jan 2019

Symptom-Aware Hybrid Fault Diagnosis Algorithm In The Network Virtualization Environment, Yuze Su, Xiangru Meng, Xiaoyang Han, Qiaoyan Kang

Turkish Journal of Electrical Engineering and Computer Sciences

As an important technology in next-generation networks, network virtualization has received more and more attention. Fault diagnosis is the crucial element for fault management and it is the process of inferring the exact failure in the network virtualization environment (NVE) from the set of observed symptoms. Although various traditional fault diagnosis algorithms have been proposed, the virtual network has some new characteristics, which include inaccessible fault information of the substrate network, inaccurate network observations, and a dynamic embedding relationship. To solve these challenges, a symptom-aware hybrid fault diagnosis (SAHFD) algorithm in the NVE is proposed in this paper. First, a …


Community Detection In Complex Networks Using A New Agglomerative Approach, Majid Arasteh, Somayeh Alizadeh Jan 2019

Community Detection In Complex Networks Using A New Agglomerative Approach, Majid Arasteh, Somayeh Alizadeh

Turkish Journal of Electrical Engineering and Computer Sciences

Complex networks are used for the representation of complex systems such as social networks. Graph analysis comprises various tools such as community detection algorithms to uncover hidden data. Community detection aims to detect similar subgroups of networks that have tight interconnections with each other while, there is a sparse connection among different subgroups. In this paper, a greedy and agglomerative approach is proposed to detect communities. The proposed method is fast and often detects high-quality communities. The suggested method has several steps. In the first step, each node is assigned to a separated community. In the second step, a vertex …


A Comprehensive Methodology To Evaluate The Performance Of A Cooperative Wireless Network, Aykut Kalaycioğlu, Ahmet Akbulut, Asim Egemen Yilmaz, Di̇lek Arslan Jan 2019

A Comprehensive Methodology To Evaluate The Performance Of A Cooperative Wireless Network, Aykut Kalaycioğlu, Ahmet Akbulut, Asim Egemen Yilmaz, Di̇lek Arslan

Turkish Journal of Electrical Engineering and Computer Sciences

Performance evaluation of a cooperative wireless communication network depends on several parameters. Many of the studies, in fact, take a limited number of performance metrics individually to reach a conclusion about the performance of a network. Besides, in general, some performance metrics might be in conflict. Thus, ignoring the combined effect of all performance criteria in the network may lead to an incorrect conception of the overall communication performance of the network. Therefore, in this study, a comprehensive evaluation methodology in terms of various metrics is proposed to calculate the performance of a cooperative wireless communication network deployment using a …


Privacy Issues In Post Dissemination On Facebook, Burcu Sayi̇n Günel, Serap Şahi̇n, Dimitris G. Kogias, Charalampos Z. Patrikakis Jan 2019

Privacy Issues In Post Dissemination On Facebook, Burcu Sayi̇n Günel, Serap Şahi̇n, Dimitris G. Kogias, Charalampos Z. Patrikakis

Turkish Journal of Electrical Engineering and Computer Sciences

With social networks (SNs) being populated by a still increasing numbers of people who take advantage of the communication and collaboration capabilities that they offer, the probability of the exposure of people's personal moments to a wider than expected audience is also increasing. By studying the functionalities and characteristics that modern SNs offer, along with the people's habits and common behaviors in them, it is easy to understand that several privacy risks may exist, many of which people may be unaware of. In this paper, we focus on users' interactions with posts in a social network (SN), using Facebook as …


Atomic-Shaped Efficient Delay And Data Gathering Routing Protocol For Underwater Wireless Sensor Networks, Wajiha Farooq, Tariq Ali, Ahmad Shaf, Muhammad Umar, Sana Yasin Jan 2019

Atomic-Shaped Efficient Delay And Data Gathering Routing Protocol For Underwater Wireless Sensor Networks, Wajiha Farooq, Tariq Ali, Ahmad Shaf, Muhammad Umar, Sana Yasin

Turkish Journal of Electrical Engineering and Computer Sciences

High end-to-end delay is a major challenge in autonomous underwater vehicle (AUV)-aided routing protocols for underwater monitoring applications. In this paper, a new routing protocol called atomic-shaped efficient delay and data gathering (ASEDG) has been introduced for underwater wireless sensor networks. The ASEDG is divided into two phases; in the first phase, the atomic-shaped trajectory model with horizontal and vertical ellipticals was designed for the movement of the AUV. In the second phase, two types of delay models were considered to make our protocol more delay efficient: member nodes (MNs) to MNs and MNs to gateway nodes (GNs). The MNs-to-MNs …


Lightweight Signature Scheme To Protect Intellectual Properties Of Internet Of Things Applications In System On Chip Field-Programmable Gate Arrays, Kokila Jagadeesh, Ramasubramanian Natarajan Jan 2019

Lightweight Signature Scheme To Protect Intellectual Properties Of Internet Of Things Applications In System On Chip Field-Programmable Gate Arrays, Kokila Jagadeesh, Ramasubramanian Natarajan

Turkish Journal of Electrical Engineering and Computer Sciences

Billions of smart objects in the edge devices offer advanced connectivity to networks which increase the security and complexity of the Internet of things (IoT) applications. To make such entities smarter heterogeneous intellectual property (IP) cores from multiple service providers are reused in system on chip platform. Enabling both chip and IP protection at post fabrication level is imperative. The IoT-based IP cores are signed with the hybrid physical unclonable function and finite state machine model to protect from cloning, misuse, unauthorized user access, and physical attacks. The extended finite-state machine is used to verify the signature, which reduces the …


Solving Vehicle Routing Problem For Multistorey Buildings Using Iterated Local Search, Osman Gökalp, Aybars Uğur Jan 2019

Solving Vehicle Routing Problem For Multistorey Buildings Using Iterated Local Search, Osman Gökalp, Aybars Uğur

Turkish Journal of Electrical Engineering and Computer Sciences

Vehicle routing problem (VRP) which is a well-known combinatorial optimisation problem that has many applications used in industry is also a generalised form of the travelling salesman problem. In this study, we defined and formulated the VRP in multistorey buildings (Multistorey VRP) for the first time and proposed a solving method employing iterated local search metaheuristic algorithm. This variant of VRP has a great potential for turning the direction of optimisation research and applications to the vertical cities area as well as the horizontal ones. Routes of part picking or placing vehicles/humans in multistorey plants can be minimised by this …


An Algorithm For Line Matching In An Image By Mapping Into An $N$-Dimensional Vector Space, Rayi̇mbek Sultanov, Ahmet Atakan, Rita Ismailova Jan 2019

An Algorithm For Line Matching In An Image By Mapping Into An $N$-Dimensional Vector Space, Rayi̇mbek Sultanov, Ahmet Atakan, Rita Ismailova

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a minimal length difference algorithm for construction of a line in an image by solving the problem of optimal contour approximation. In this algorithm, a method for finding interest points is proposed, and the object matching (classification) is done by mapping interest points onto a vector space. In cases where the lines in the representation of the images are not smooth, the algorithm converges rapidly. The results of the experiments showed that for convergence of the contour simplification, there were 5-6 iterations for $n = 13$. To check how close the curve approximation calculated by the algorithm …


Hgab3c: A New Hybrid Global Optimization Algorithm, Kamaljeet Kaur, Shakti Kumar, Jyoti Saxena Jan 2019

Hgab3c: A New Hybrid Global Optimization Algorithm, Kamaljeet Kaur, Shakti Kumar, Jyoti Saxena

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new optimization algorithm, namely HGAB3C, and presents its performance on the CEC-2014 test suite. In HGAB3C, simple genetic algorithms (GAs) and big bang-big crunch (BB-BC) are hybridized. The algorithm carries out global searches using a simple GA. In every generation the BB-BC algorithm is used to carry out local searches. The addition of local search has improved the capability of simple GAs significantly. The performance of the proposed algorithm is compared with 17 other optimization algorithms on all 30 functions of the CEC-2014 benchmark suite. It is observed that HGAB3C outperforms all other algorithms on 4 …


An Improved Imperialist Competitive Algorithm For Global Optimization, Ting You, Yueli Hu, Peijiang Li, Yinggan Tang Jan 2019

An Improved Imperialist Competitive Algorithm For Global Optimization, Ting You, Yueli Hu, Peijiang Li, Yinggan Tang

Turkish Journal of Electrical Engineering and Computer Sciences

The imperialist competitive algorithm (ICA), inspired by sociopolitical behavior in the real world, is a new optimization algorithm. The ICA shows great potential to solve complex optimization problems. In order to improve the ICA's exploration ability and speed up its convergence, two improved schemes are proposed in this paper. The first scheme presents a new possession probability in the imperialistic competition phase. Inspired by geopolitics, not only the power of the empire but also the distance between the imperialists are taken into account in calculating the new possession probability. The second scheme introduces the wavelet mutation operator into the original …


Test Case Prioritization And Distributed Testing Of Object-Oriented Program, Vipin Kumar K S, Sheena Mathew Jan 2019

Test Case Prioritization And Distributed Testing Of Object-Oriented Program, Vipin Kumar K S, Sheena Mathew

Turkish Journal of Electrical Engineering and Computer Sciences

Software systems have increased in size and complexity. As a result, object-oriented programming (OOP) is increasingly being used in the development of such large and complex systems. Traditional procedural programming requires a design method that follows a sequential flow of control, which is difficult to follow in the case of large systems design. Thinking in terms of real-life objects and their interactions makes design easier in the case of OOP. However, OOP comes with its own set of disadvantages and testing is one of them. Testing of such systems requires much more effort and time. In our approach the program …


A Robust Ensemble Feature Selector Based On Rank Aggregation For Developing New Vo\Textsubscript{2}Max Prediction Models Using Support Vector Machines, Fatih Abut, Mehmet Fati̇h Akay, James George Jan 2019

A Robust Ensemble Feature Selector Based On Rank Aggregation For Developing New Vo\Textsubscript{2}Max Prediction Models Using Support Vector Machines, Fatih Abut, Mehmet Fati̇h Akay, James George

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new ensemble feature selector, called the majority voting feature selector (MVFS), for developing new maximal oxygen uptake (VO2max) prediction models using a support vector machine (SVM). The approach is based on rank aggregation, which meaningfully utilizes the correlation among the relevance ranks of predictor variables given by three state-of-the-art feature selectors: Relief-F, minimum redundancy maximum relevance (mRMR), and maximum likelihood feature selection (MLFS). By applying the SVM combined with MVFS on a self-created dataset containing maximal and submaximal exercise data from 185 college students, several new hybrid (VO2max) prediction models have been created. To compare the …


Incremental Author Name Disambiguation Using Author Profile Models And Self-Citations, Ijaz Hussain, Sohail Asghar Jan 2019

Incremental Author Name Disambiguation Using Author Profile Models And Self-Citations, Ijaz Hussain, Sohail Asghar

Turkish Journal of Electrical Engineering and Computer Sciences

Author name ambiguity in bibliographic databases (BDs) such as DBLP is a challenging problem that degrades the information retrieval quality, citation analysis, and proper attribution to the authors. It occurs when several authors have the same name (homonym) or when an author publishes under several name variants (synonym). Traditionally, much research has been conducted to disambiguate whole bibliographic database at once whenever some new citations are added in these BDs. However, it is more time-consuming and discards the manual disambiguation effects (if any). Only a few incremental author name disambiguation methods are proposed but these methods produce fragmented clusters which …


Biometric Person Authentication Framework Using Polynomial Curve Fitting-Based Ecg Feature Extraction, Şahi̇n Işik, Kemal Özkan, Semi̇h Ergi̇n Jan 2019

Biometric Person Authentication Framework Using Polynomial Curve Fitting-Based Ecg Feature Extraction, Şahi̇n Işik, Kemal Özkan, Semi̇h Ergi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

The applications of modern biometric techniques for person identification systems rapidly increase for meeting the rising security demands. The distinctive physiological characteristics are more correctly measurable and trustworthy since previous measurements are not appropriately made for physiological properties. While a variety of strategies have been enabled for identification, the electrocardiogram (ECG)-based approaches are popular and reliable techniques in the senses of measurability, singularity, and universal awareness of heartbeat signals. This paper presents a new ECG-based feature extraction method for person identification using a huge amount of ECG recordings. First of all, 1800 heartbeats for each of the 36 subjects have …


I See Ek: A Lightweight Technique To Reveal Exploit Kit Family By Overall Url Patterns Of Infection Chains, Emre Süren, Peli̇n Angin, Nazi̇fe Baykal Jan 2019

I See Ek: A Lightweight Technique To Reveal Exploit Kit Family By Overall Url Patterns Of Infection Chains, Emre Süren, Peli̇n Angin, Nazi̇fe Baykal

Turkish Journal of Electrical Engineering and Computer Sciences

The prevalence and nonstop evolving technical sophistication of exploit kits (EKs) is one of the most challenging shifts in the modern cybercrime landscape. Over the last few years, malware infections via drive-by download attacks have been orchestrated with EK infrastructures. Malicious advertisements and compromised websites redirect victim browsers to web-based EK families that are assembled to exploit client-side vulnerabilities and finally deliver evil payloads. A key observation is that while the webpage contents have drastic differences between distinct intrusions executed through the same EK, the patterns in URL addresses stay similar. This is due to the fact that autogenerated URLs …


Adaptive Canonical Correlation Analysis For Harmonic Stimulation Frequencies Recognition In Ssvep-Based Bcis, Sahar Sadeghi, Ali Maleki Jan 2019

Adaptive Canonical Correlation Analysis For Harmonic Stimulation Frequencies Recognition In Ssvep-Based Bcis, Sahar Sadeghi, Ali Maleki

Turkish Journal of Electrical Engineering and Computer Sciences

Steady-state visual evoked potential (SSVEP) is the brain's response to quickly repetitive visual stimulus with a certain frequency. To increase the information transfer rate (ITR) in SSVEP-based systems, due to the frequency resolution restriction, we are forced to broaden the frequency range, which causes harmonic frequencies to come into the stimulation frequency range. Conventional canonical correlation analysis (CCA) may be associated with error for SSVEP frequency recognition at stimulation frequencies with harmonic relations. The number of harmonics considered to construct reference signals are determined adaptively; for frequencies whose second harmonic exists in the frequency range, two harmonics are used, and …


Scale-Invariant Mfccs For Speech/Speaker Recognition, Zekeri̇ya Tüfekci̇, Gökay Di̇şken Jan 2019

Scale-Invariant Mfccs For Speech/Speaker Recognition, Zekeri̇ya Tüfekci̇, Gökay Di̇şken

Turkish Journal of Electrical Engineering and Computer Sciences

The feature extraction process is a fundamental part of speech processing. Mel frequency cepstral coefficients (MFCCs) are the most commonly used feature types in the speech/speaker recognition literature. However, the MFCC framework may face numerical issues or dynamic range problems, which decreases their performance. A practical solution to these problems is adding a constant to filter-bank magnitudes before log compression, thus violating the scale-invariant property. In this work, a magnitude normalization and a multiplication constant are introduced to make the MFCCs scale-invariant and to avoid dynamic range expansion of nonspeech frames. Speaker verification experiments are conducted to show the effectiveness …


Extracting Accent Information From Urdu Speech For Forensic Speaker Recognition, Falak Tahir, Sajid Saleem, Ayaz Ahmad Jan 2019

Extracting Accent Information From Urdu Speech For Forensic Speaker Recognition, Falak Tahir, Sajid Saleem, Ayaz Ahmad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method for extraction of accent information from Urdu speech signals. Accent is used in speaker recognition system especially in forensic cases and plays a vital role in discriminating people of different groups, communities and origins due to their different speaking styles. The proposed method is based on Gaussian mixture model-universal background model (GMM-UBM), mel-frequency cepstral coefficients (MFCC), and a data augmentation (DA) process. The DA process appends features to base MFCC features and improves the accent extraction and forensic speaker recognition performances of GMM-UBM. Experiments are performed on an Urdu forensic speaker corpus. The experimental …


A Hybrid Of Fuzzy Theory And Quadratic Function For Estimating And Refining Transmission Map, Jyun-Yu Jhang, Chengjian Lin, Kuu-Young Young, Chin-Teng Lin Jan 2019

A Hybrid Of Fuzzy Theory And Quadratic Function For Estimating And Refining Transmission Map, Jyun-Yu Jhang, Chengjian Lin, Kuu-Young Young, Chin-Teng Lin

Turkish Journal of Electrical Engineering and Computer Sciences

In photographs captured in outdoor environments, particles in the air cause light attenuation and degrade image quality. This effect is especially obvious in hazy environments. In this study, a fuzzy theory is proposed to estimate the transmission map of a single image. To overcome the problem of oversaturation in dehazed images, a quadratic-function-based method is proposed to refine the transmission map. In addition, the color vector of the atmospheric light is estimated using the top 1\% of the brightest light area. Finally, the dehazed image is reconstructed using the transmission map and the estimated atmospheric light. Experimental results demonstrate that …


A Novel Hardware-Efficient Spatial Orientation Tree-Based Image Compression Algorithm And Its Field Programmable Gate Array Implementation, Mohd Rafi Lone, Najeeb-Ud-Din Hakim Jan 2019

A Novel Hardware-Efficient Spatial Orientation Tree-Based Image Compression Algorithm And Its Field Programmable Gate Array Implementation, Mohd Rafi Lone, Najeeb-Ud-Din Hakim

Turkish Journal of Electrical Engineering and Computer Sciences

Set partitioning in hierarchical trees (SPIHT) has become a popular research topic for more than a decade now. This is because it is simple, besides having compression efficiency close to the state-of-the-art JPEG2000 standard. The main drawback of SPIHT is that it uses three lists to store addresses of coefficients during its operation. These lists are dynamic and in worst cases need to store more number of addresses than total coefficients. In this work, a novel hardware-efficient spatial orientation tree-based algorithm is proposed and its hardware implementation is carried out. The wavelet transformed image is partitioned into 2 $\times$ 2 …


Trmor: A Finite-State-Based Morphological Analyzer For Turkish, Ayla Kayabaş, Helmut Schmi̇d, Ahmet Ercan Topcu, Özkan Kiliç Jan 2019

Trmor: A Finite-State-Based Morphological Analyzer For Turkish, Ayla Kayabaş, Helmut Schmi̇d, Ahmet Ercan Topcu, Özkan Kiliç

Turkish Journal of Electrical Engineering and Computer Sciences

Morphological analysis is an important component of natural language processing systems like spelling correction tools, parsers, machine translation systems, and dictionary tools. In this paper, we present TRMOR, a morphological analyzer for Turkish, which uses the SFST tool (Stuttgart Finite-State Transducer). TRMOR can be freely used for academic research (see http://www.cis.uni-muenchen.de/~schmid/tools/SFST/). It covers a large part of Turkish morphology including inflection, derivation, and some compounding. It uses morphotactic and morphophonological rules and a stem lexicon. We describe the morphological structure of Turkish, explain the phonological and morphological rules implemented in TRMOR, evaluate the system, and test it in special cases. …


Damping Of Low-Frequency Oscillation In Power Systems Using Hybrid Renewable Energy Power Plants, Mahdi Saadatmand, Babak Mozafari, Gevork Babamalek Gharehpetian, Soodabeh Soleymani Jan 2019

Damping Of Low-Frequency Oscillation In Power Systems Using Hybrid Renewable Energy Power Plants, Mahdi Saadatmand, Babak Mozafari, Gevork Babamalek Gharehpetian, Soodabeh Soleymani

Turkish Journal of Electrical Engineering and Computer Sciences

Global warming, increase in environmental pollution, and high cost of electrical power generation using fossil fuels are considered the most important reasons for the application of renewable energy power plants (REPPs) around the world. In recent years, a new generation of REPPs called hybrid renewable energy power plants (HREPPs) has been implemented in order to have higher efficiency and reliability than conventional REPPs such as wind power plants and photovoltaic power plants. The HREPPs include two or more renewable energy generation units such as wind turbine generation units, and PV generation units. In case of high penetration of these types …


Bidding Strategy For Generators Considering Ramp Rates In A Day-Ahead Electricity Market, Satyendra Singh, Manoj Fozdar Jan 2019

Bidding Strategy For Generators Considering Ramp Rates In A Day-Ahead Electricity Market, Satyendra Singh, Manoj Fozdar

Turkish Journal of Electrical Engineering and Computer Sciences

In a day-ahead electricity market, competitive bidding strategy plays a vital role for power suppliers to maximize their profit. In this type of market, each power supplier submits a set of hourly production prices and offers capacity for the next period. The market operator, after receiving this data along with forecasted hourly load from the demand side, allocates production output to each unit. Power suppliers face the problem in trading their offers in the market, due to the uncertain behavior of competitive power suppliers and power demand. Therefore, the power supplier requires a suitable bidding strategy for handling uncertainty in …


A Robust Smes Control For Enhancing Stability Of Distribution Systems Fed From Intermittent Wind Power Generation, Sayed Said, Mokhtar Aly, Balint Hartmann Jan 2019

A Robust Smes Control For Enhancing Stability Of Distribution Systems Fed From Intermittent Wind Power Generation, Sayed Said, Mokhtar Aly, Balint Hartmann

Turkish Journal of Electrical Engineering and Computer Sciences

The voltage and frequency stability issues of power systems are the main challenges that arise from high penetration levels of wind energy systems. This paper presents an effective solution for voltage and frequency stability problems by using a superconducting magnetic energy storage (SMES) system controlled with a fuzzy logic controller (FLC). The proposed control system can suppress the voltage and frequency fluctuations due to the high variations of wind speed. In addition, the proposed control system is suitable for both balanced and unbalanced distribution systems with high penetration levels of wind turbines (WTs). A squirrel cage induction generator (SCIG) is …


Heat Flux Capacity Measurement And Improvement For The Test Of Superconducting Logic Circuits In Closed-Cycle Cryostats, Sasan Razmkhah, Ali̇ Bozbey Jan 2019

Heat Flux Capacity Measurement And Improvement For The Test Of Superconducting Logic Circuits In Closed-Cycle Cryostats, Sasan Razmkhah, Ali̇ Bozbey

Turkish Journal of Electrical Engineering and Computer Sciences

With the current progress of superconducting integrated circuits, circuit complexities have reached more than 100,000 Josephson junctions. At the laboratory environment, circuit tests are generally being conducted at liquid Helium environments. With the commercialization of the superconducting integrated circuit-based systems and/or price increase of liquid Helium, utilization of the closed-cycle systems will be inevitable. Even though it is possible to implement closed-cycle systems with quite substantial excess cooling powers after all the wirings and peripheral circuits, one point not to be overlooked is the power density at the superconducting chips. We have observed that the circuits designed for operation at …