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Full-Text Articles in Physical Sciences and Mathematics

Robust Adaptive Fuzzy Control Of A Three-Phase Active Power Filter Based On Feedback Linearization, Shixi Hou, Juntao Fei Jan 2017

Robust Adaptive Fuzzy Control Of A Three-Phase Active Power Filter Based On Feedback Linearization, Shixi Hou, Juntao Fei

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a robust adaptive fuzzy control system using feedback linearization is proposed for a three-phase active power filter (APF). The APF system is divided into two separate loops: the current dynamic inner loop and the DC voltage dynamic outer loop. Adaptive fuzzy tracking control using feedback linearization is employed for the current dynamic inner loop to overcome the drawbacks of the conventional method. The proposed controller can ensure proper tracking of the reference current and impose desired dynamic behavior, giving robustness and insensitivity to parameter variations. Adaptive fuzzy proportional-integral control is applied to the DC voltage dynamics outer …


Gica: Imperialist Competitive Algorithm With Globalization Mechanism For Optimization Problems, Yousef Abdi, Mahmoud Lak, Yousef Seyfari Jan 2017

Gica: Imperialist Competitive Algorithm With Globalization Mechanism For Optimization Problems, Yousef Abdi, Mahmoud Lak, Yousef Seyfari

Turkish Journal of Electrical Engineering and Computer Sciences

The imperialist competitive algorithm (ICA) is a recent global search strategy developed based on human social evolutionary phenomena in the real world. However, the ICA has the drawback of trapping in local optimum solutions when used for high-dimensional or complex multimodal functions. In order to deal with this situation, in this paper an improved ICA, named GICA, is proposed that can enhance ICA performance by using a new assimilation method and establishing a relationship between countries inspired by the globalization concept in the real world. The proposed algorithm is evaluated using a set of well-known benchmark functions for global optimization. …


Adaptive Control Of Pure-Feedback Systems In The Presence Of Parametric Uncertainties, Mehrnoosh Asadi, Heydar Toossian Shandiz Jan 2017

Adaptive Control Of Pure-Feedback Systems In The Presence Of Parametric Uncertainties, Mehrnoosh Asadi, Heydar Toossian Shandiz

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this study is to investigate an adaptive control approach for completely nonaffine pure-feedback systems with linear/nonlinear parameterization. In this approach, the parameter separation technique and the idea of the positive function of linearly connected parameters are coupled effectively with the combination of backstepping and time-scale separation. Subsequently, a fast dynamical equation is derived from the original subsystem, where the solution is sought to approximate the corresponding ideal virtual/actual control inputs. Furthermore, the adaptation law of unknown parameters can be derived based on Lyapunov theory in the backstepping technique and there is no need to design a state …


An Effective Empirical Approach To Voip Traffic Classification, Nazar Abbas Saqib, Yaqoot Shakeel, Moazzam Ali Khan, Hasan Mehmood, Muhammad Zia Jan 2017

An Effective Empirical Approach To Voip Traffic Classification, Nazar Abbas Saqib, Yaqoot Shakeel, Moazzam Ali Khan, Hasan Mehmood, Muhammad Zia

Turkish Journal of Electrical Engineering and Computer Sciences

It is beneficial for telecommunication authorities and Internet service providers (ISPs) to classify and detect voice traffic. It can help them to block unsubscribed users from using their services, which saves them huge revenues. Voice packets can be detected easily, but it becomes complicated when the application or port information in the packet header is hidden due to some secure mechanism such as encryption. This work provides effective voice packet classification and detection based on behavioral and statistical analysis, which is independent of any application, security protocol, or encryption mechanism. First we have made initial assessments through packet feature analysis …


Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken Jan 2017

Dual Broadband Antenna With Compact Double Ring Radiators For Ieee 802.11 Ac/B/G/N Wlan Communication Applications, Meri̇h Palandöken

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a dual broadband antenna is proposed for WLAN communication modules supported by the IEEE 802.11 ac/b/g/n standard. The antenna design is based on two interspaced electrically small split-ring resonators, each of which is directly fed through the stepped impedance microstrip line with an optimized electromagnetic coupling distance in between. The proposed dual band antenna operates in the lower frequency band from 2.3 GHz up to 3 GHz with 2.65 GHz center frequency (26.4 % bandwidth) and in the higher frequency band from 4.7 GHz up to 6 GHz with 5.35 GHz center frequency (24.3% bandwidth). The radiating …


Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal Jan 2017

Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal

Turkish Journal of Electrical Engineering and Computer Sciences

An electroencephalogram (EEG) is an electrical signal in microvolts captured noninvasively from the brain, which provides important and unique information about the brain. The frequency of an EEG signal lies between 0 and 100 Hz. Decomposition of an EEG signal into various bands such as alpha, beta, delta, theta, and gamma is essential in seizure-related studies. EEGs play a key role in the diagnosis of epileptic seizures and neurological disorders. In this paper, multiple wavelet families for decomposition and reconstruction are explored and are compared based on risk functions and reconstruction measures. While dealing with the wavelets it is a …


Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe Jan 2017

Model-Based Fault Analysis Of A High-Voltage Circuit Breaker Operating Mechanism, Ali Forootani, Ali Akbar Afzalian, Ali Nadian Ghohmshe

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a dynamic model is developed for high-voltage circuit breakers to extract fault features and causes. Lagrange's method is applied using geometric equations of mechanism components to write the model. Unlike previous approaches, the proposed method reveals and analyzes all types of circuit breaker operating mechanism faults. Early fault detection, which is a vital requirement of the fault diagnosis system, becomes feasible by keeping track of changes in the contact travel curve in the proposed model. Resulting faults in the travel curve are analyzed mathematically in order to find out the exact origin of the fault. Field test …


Analysis Of Feature Detector And Descriptor Combinations With A Localization Experiment For Various Performance Metrics, Ertuğrul Bayraktar, Pinar Boyraz Jan 2017

Analysis Of Feature Detector And Descriptor Combinations With A Localization Experiment For Various Performance Metrics, Ertuğrul Bayraktar, Pinar Boyraz

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this study is to provide a detailed performance comparison of feature detector/descriptor methods, particularly when their various combinations are used for image-matching. The localization experiments of a mobile robot in an indoor environment are presented as a case study. In these experiments, 3090 query images and 127 dataset images were used. This study includes five methods for feature detectors (features from accelerated segment test (FAST), oriented FAST and rotated binary robust independent elementary features (BRIEF) (ORB), speeded-up robust features (SURF), scale invariant feature transform (SIFT), and binary robust invariant scalable keypoints (BRISK)) and five other methods for …


Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications, Emre Avci, Mehmet Uçar Jan 2017

Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications, Emre Avci, Mehmet Uçar

Turkish Journal of Electrical Engineering and Computer Sciences

The 3-level T-type neutral point clamped (T-NPC) inverter has become the most popular multilevel inverter used in low-voltage applications. However, the realization of a bidirectional switch located at the midpoint leg of the T-NPC inverter is achieved using two insulated gate bipolar transistors (IGBTs) with two antiparallel diodes. Power dissipation in these switches is high since there are two semiconductors (an IGBT and a diode) in the current path at the midpoint leg. Switch losses can be reduced and thus the highest conversion efficiency can be achieved if the bidirectional switches in the T-NPC inverter are replaced by highly efficient …


Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes, Obada Abdallah, Ammar Abu Hudrouss Jan 2017

Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes, Obada Abdallah, Ammar Abu Hudrouss

Turkish Journal of Electrical Engineering and Computer Sciences

Space-time code can be implemented in wireless relay networks when all relays cooperate to generate the code at the receiver. In this case, it is called distributed space-time code. If the channel response changes very quickly, the idea of differential space-time coding is needed to overcome the difficulty of updating the channel state information at the receiver. As a result, the transmitted signal can be demodulated without any knowledge of the channel state information at the relays or the receiver. In this paper, development of new low decoding complexity distributed differential space-time codes is considered. The developed codes are designed …


Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh Jan 2017

Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh

Turkish Journal of Electrical Engineering and Computer Sciences

A flexible (2 $\times $ 1) multiple-input, multiple-output (MIMO) antenna with an electromagnetic band gap (EBG) unit cell is designed and measured. The proposed MIMO antenna is based on a circular slotted patch antenna to work at 3.5 GHz. An EBG unit cell is used to reduce the effect of the inherent mutual coupling produced between the closely spaced MIMO elements. The results show that the measured mutual coupling has been reduced by -11.6 dB (from -10 dB to -21.6 dB), and the measured realized gain has been increased by 1.074 dBi (from 1.59 dBi to 2.66 dBi). An improvement …


Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden Jan 2017

Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden

Turkish Journal of Electrical Engineering and Computer Sciences

A new class of scheduling algorithms is proposed for disk drive scheduling. As opposed to choosing the request with the shortest access time in conventional shortest access time first (SATF) algorithms, we choose an ordered sequence of pending I/O requests at the scheduling instant with the shortest cumulative access time. Additionally, we introduce flexibility for forthcoming requests to alter the chosen sequence. Simulation results are provided to validate the effectiveness of the proposed disk scheduler. Throughput gains of 3% and above are shown to be attainable, although this occurs at the expense of increased computational complexity.


Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör Jan 2017

Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, smart meters, sensors, and advanced electricity tariff mechanisms such as time-of-use (ToU), critical peak pricing tariff, and real time tariff enable electricity consumption optimization for residential consumers. The main scope of such mechanisms is to promote peak shaving, which leads to minimization of technical losses and avoidance (or delay) of grid onerous investments. This paper proposes a method to determine the optimum capacity of a storage device (SD) that significantly contributes to peak shaving of electricity consumption for residential consumers. Detailed modelling of diverse electric appliances' behavior and consumers' necessities is addressed in order to determine the optimum capacity …


Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani Jan 2017

Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani

Turkish Journal of Electrical Engineering and Computer Sciences

Reactive power optimization (RPO) in a power system is a rudimentary necessity for the reduction of the loss of power. For the requirement of a unity power factor in the RPO system, the reduction of the system losses is ensured. The pivotal requirements of a power system are inclusive of a perfect compensation technique and methodology for stable reactive power compensation. The proposed concept in this paper utilizes the different reactive power optimization algorithms and performs a comparison. The process is accomplished by the use of IEEE 6-bus, 14-bus, and 30-bus systems to test the optimization technique. The conclusive information …


A Modified Genetic Algorithm For A Special Case Of The Generalized Assignment Problem, Murat Dörterler, Ömer Faruk Bay, Mehmet Ali̇ Akcayol Jan 2017

A Modified Genetic Algorithm For A Special Case Of The Generalized Assignment Problem, Murat Dörterler, Ömer Faruk Bay, Mehmet Ali̇ Akcayol

Turkish Journal of Electrical Engineering and Computer Sciences

Many central examinations are performed nationwide in Turkey. These examinations are held simultaneously throughout Turkey. Examinees attempt to arrive at the examination centers at the same time and they encounter problems such as traffic congestion, especially in metropolises. The state of mind that this situation puts them into negatively affects the achievement and future goals of the test takers. Our solution to minimize the negative effects of this issue is to assign the test takers to closest examination centers taking into account the capacities of examination halls nearby. This solution is a special case of the generalized assignment problem (GAP). …


Iris Nevus Diagnosis: Convolutional Neural Network And Deep Belief Network, Oyebade Oyedotun, Adnan Khashman Jan 2017

Iris Nevus Diagnosis: Convolutional Neural Network And Deep Belief Network, Oyebade Oyedotun, Adnan Khashman

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents the diagnosis of iris nevus using a convolutional neural network (CNN) and deep belief network (DBN). Iris nevus is a pigmented growth (tumor) found in the front of the eye or around the pupil. It is seen that racial and environmental factors affect the iris color (e.g., blue, hazel, brown) of patients; hence, pigmented growths may be masked in the eye background or iris. In this work, some image processing techniques are applied to images to reinforce areas of interests in them, after which the considered classifiers are trained. We describe the automated diagnosis of iris nevus …


A Hybrid Of Sliding Mode Control And Fuzzy Logic Control Using A Fuzzy Supervisory Switched System For Dc Motor Speed Control, Husain Ahmed, Abha Rajoriya Jan 2017

A Hybrid Of Sliding Mode Control And Fuzzy Logic Control Using A Fuzzy Supervisory Switched System For Dc Motor Speed Control, Husain Ahmed, Abha Rajoriya

Turkish Journal of Electrical Engineering and Computer Sciences

In many applications of DC motor speed control systems, PID controllers are mostly used. Such control schemes do not show good performance when input and load torque disturbances are applied. This paper shows that sliding mode (SM) can give better control due to its robust property but it has an unwanted chattering problem associated with it, which is harmful to the plant. To limit this problem a hybrid controller is presented in which a fuzzy controller is combined with the SM controller by a fuzzy supervisory system in such a way that the SM controller works in transient state and …


Planar Array Of Right-Angled Isosceles Triangular Microstrip Antenna Using Koch And Meander Lines For The Internet Of Things, Manisha Gupta, Vinita Mathur Jan 2017

Planar Array Of Right-Angled Isosceles Triangular Microstrip Antenna Using Koch And Meander Lines For The Internet Of Things, Manisha Gupta, Vinita Mathur

Turkish Journal of Electrical Engineering and Computer Sciences

An ultrawideband antenna array using a right-angled isosceles triangular microstrip antenna as a basic element is presented using inset feed for applications in the Internet of things. A Koch fractal antenna array with defected ground plane is used to generate multiband applications. Further, meander lines are added to increase the equivalent inductance that reduces the size of the antenna and increases the bandwidth and gain. Antenna arrays have been constructed and experimentally studied. The measured results show good agreement with the numerical prediction and wideband operation.


Dynamic Slot-Based Carrier Scheduling Scheme For Downlink Multimedia Traffic Over Lte Advanced Networks With Carrier Aggregation, Ramachandran Vijayarani, Lakshmanan Nithyanandan Jan 2017

Dynamic Slot-Based Carrier Scheduling Scheme For Downlink Multimedia Traffic Over Lte Advanced Networks With Carrier Aggregation, Ramachandran Vijayarani, Lakshmanan Nithyanandan

Turkish Journal of Electrical Engineering and Computer Sciences

Carrier aggregation (CA) in long-term evolution advanced (LTE-A) networks is a promising tool for providing bandwidth extension for high data rate communication. In CA, the efficient scheduling of carriers has imposed a new challenge in the design of delay-sensitive carrier scheduling for mobile multimedia applications. In this paper, a new dynamic slot-based carrier scheduling scheme has been proposed for efficient resource allocation to support the quality of service (QoS) of mobile traffic over CA transmission. The key idea of this scheduling is the allocation of slots for each component carrier based on the queue state information, taking into consideration the …


A New Segmentation Method Of Cerebral Mri Images Based On The Fuzzy C-Means Algorithm, Mohamed Zaki Abderrezak, Mouatez Billah Chibane, Karim Mansour Jan 2017

A New Segmentation Method Of Cerebral Mri Images Based On The Fuzzy C-Means Algorithm, Mohamed Zaki Abderrezak, Mouatez Billah Chibane, Karim Mansour

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this work is to present a new method for cerebral MRI image segmentation based on modification of the fuzzy c-means (FCM) algorithm. We used local and nonlocal information distance in the initial function of the robust FCM model. The obtained results of the classification of MRI images showed the effectiveness of the suggested model. Calculation of the similarity index confirms that our method is well adapted to MRI images even in the presence of noise.


Effect Of Uniform And Dolph-Chebyshev Excitations On The Performance Of Circular Array Antennas, Mohan Kachalai Narasimman, Yogesh Kumar Choukiker, Srinivasa Rao Zinka, Kannadassan Dhanaraj Jan 2017

Effect Of Uniform And Dolph-Chebyshev Excitations On The Performance Of Circular Array Antennas, Mohan Kachalai Narasimman, Yogesh Kumar Choukiker, Srinivasa Rao Zinka, Kannadassan Dhanaraj

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and simulation of microstrip circular antenna arrays and studies the effect of excitation with uniform and Dolph--Chebyshev distribution. With side lobe level of 20 dB and 8 microstrip circular patches, the circular array has been demonstrated with minimum grating lobes. The effects of patch and antenna array length on directivity, radiation patterns, and side lobe are also studied in detail. It is found that these antenna arrays are suitable for radar application.


Adaptive Joint Block-Weighted Collaborative Representation For Facial Expression Recognition, Zhe Sun, Zhengping Hu, Meng Wang, Shuhuan Zhao Jan 2017

Adaptive Joint Block-Weighted Collaborative Representation For Facial Expression Recognition, Zhe Sun, Zhengping Hu, Meng Wang, Shuhuan Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

Facial expression recognition (FER) plays a significant role in human-computer interactions. Recently, regularized linear representation-based classification has achieved satisfying results in FER. Considering that different blocks in a sample should contribute differently to the representation and classification, we propose an adaptive joint block-weighted collaborative representation-based classification (JBW_CRC) method to effectively exploit the similarity and distinctiveness of different blocks. In JBW_CRC, samples are divided into different blocks and each block of the query sample is represented as a feature vector. Each feature vector is coded on its related block dictionary, which considers the similarity among the feature vectors. Additionally, the distinctiveness …


Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk Jan 2017

Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, based on the theory of traveling waves, the fault distances on long transmission lines with various series-compensation levels are determined using transient current and voltage frequencies. Transmission lines with series compensation are modeled using Alternative Transients Program software with frequency-dependent effects on the line included in the simulation. The transient current and voltage signals are obtained from the model. A fast Fourier transform is used for frequency-domain conversion and fault location is estimated from the frequencies of fault-generated harmonics in the transient spectrum. The algorithm is implemented in MATLAB. To investigate the effect of compensation on accuracy, …


A Spatial Load Forecasting Method Based On Load Regularity Analysis, Bai Xiao, Tongtong Liu Jan 2017

A Spatial Load Forecasting Method Based On Load Regularity Analysis, Bai Xiao, Tongtong Liu

Turkish Journal of Electrical Engineering and Computer Sciences

A new method, based on regularity analysis of cellular load, is presented to determine the reasonable maximum of the load density index method of spatial load forecasting (SLF). Through analysis of cellular historical load data, each cellular load is decomposed into regular and random components. The regular part is used to reveal the regularity of the cellular load in different cycles, using random components to describe and characterize the intrinsic error of the cellular load. Adverse effects that occur by eliminating random components to suppress the intrinsic error allow extraction of the maximum of the regular part as the Class …


Time-Jerk Optimal Trajectory Planning Of A 7-Dof Redundant Robot, Shaotian Lu, Jingdong Zhao, Li Jiang, Hong Liu Jan 2017

Time-Jerk Optimal Trajectory Planning Of A 7-Dof Redundant Robot, Shaotian Lu, Jingdong Zhao, Li Jiang, Hong Liu

Turkish Journal of Electrical Engineering and Computer Sciences

In order to improve the efficiency and smoothness of a robot and reduce its vibration, an algorithm called the augmented Lagrange constrained particle swarm optimization (ALCPSO), which combines constrained particle swarm optimization with the augmented Lagrange multiplier method to realize time-jerk (defined as the derivative of the acceleration) optimal trajectory planning is proposed. Kinematic constraints such as joint velocities, accelerations, jerks, and traveling time are considered. The ALCPSO algorithm is used to avoid local optimization because a new particle swarm is newly produced at each initial time process. Additionally, the best value obtained from the former generation is saved and …


Case Study On Wavelet Choice Based On Statistical Image Quality Measures, Igor Vujovic, Ivica Kuzmanic Jan 2017

Case Study On Wavelet Choice Based On Statistical Image Quality Measures, Igor Vujovic, Ivica Kuzmanic

Turkish Journal of Electrical Engineering and Computer Sciences

Surveillance applications are under many negative influences, which should be suppressed, because these negative influences result in incorrectness of the motion mask. Suppression of several conflicting requirements can be optimized by a multiobjective approach. This paper proposes a multiobjective approach to selection of wavelets based on two main objectives: statistical image quality measures and execution time. Execution time is a measure of wavelets complexity. Segmentation is the final goal in order to insure precise operation of any surveillance algorithm. This paper presents a case study considering one, two, three, and four goals for wavelet selection comparison. Different wavelets are found …


Robust Local Parameter Estimator Based On Least Absolute Value Estimator, Volkan Özdemi̇r, Murat Göl Jan 2017

Robust Local Parameter Estimator Based On Least Absolute Value Estimator, Volkan Özdemi̇r, Murat Göl

Turkish Journal of Electrical Engineering and Computer Sciences

Changes in weather conditions such as temperature and humidity, miscommunication between the control center and circuit breaker transducers and tap changers, and inaccurate manufacturing data may cause parameter errors. Because of incorrect parameters, the state estimator may provide biased state estimates, which may lead to many serious economic and operational results. In order to prevent that, one must identify and correct those parameter errors. This work proposes a local parameter estimator based on the least absolute value (LAV) estimator, which is known to be robust against bad measurements, i.e. measurements with gross error. Considering the increasing number of phasor measurement …


Sphere Decoding Algorithm For Multiuser Detection In A Distributed Antenna System, Fahad Khawaja, Alam Zaib, Shahid Khattak Jan 2017

Sphere Decoding Algorithm For Multiuser Detection In A Distributed Antenna System, Fahad Khawaja, Alam Zaib, Shahid Khattak

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the impact of initial search radius on the complexity and performance of a sphere decoding algorithm is investigated for different user positions within a distributed antenna system. In a distributed antenna system, users can take up random positions within the cell clusters. The channel matrix can therefore take up infinitely different forms. In the presented work, a distributed antenna system with three different user positions in the cooperating cells is considered by employing different channel matrices. The effect on the complexity and performance of the sphere decoder due to the choice of the initial sphere radius is …


A Multifunctional Dstatcom For Power Quality Improvement, Mohammad Mahdianpoor, Arash Kiyoumarsi, Mohammad Ataei, Rahmat Allah Hooshmand, Houshang Karimi Jan 2017

A Multifunctional Dstatcom For Power Quality Improvement, Mohammad Mahdianpoor, Arash Kiyoumarsi, Mohammad Ataei, Rahmat Allah Hooshmand, Houshang Karimi

Turkish Journal of Electrical Engineering and Computer Sciences

The distribution static compensator (DSTATCOM) is used for various purposes such as load balancing, harmonic rejection, and power factor correction (PFC) in power distribution networks. In unbalanced and polluted power systems, the classic definition of power factor cannot be used for PFC due to the existence of harmonics and negative sequence components in voltage and current waveforms. In this paper, PFC is performed using the IEEE power factor definition for harmonic and unbalanced environments. Moreover, the application of a proportional-resonant (PR) controller is proposed as an effective controller in the stationary frame for DSTATCOM performance improvement. The PR controller is …


Pixel- Versus Object-Based Classification Of Forest And Agricultural Areas From Multiresolution Satellite Images, Di̇jle Boyaci, Mustafa Erdoğan, Ferruh Yildiz Jan 2017

Pixel- Versus Object-Based Classification Of Forest And Agricultural Areas From Multiresolution Satellite Images, Di̇jle Boyaci, Mustafa Erdoğan, Ferruh Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Managing of natural resources including agriculture and forestry is a very important subject for governments and decision makers. Up-to-date, accurate, and timely geospatial information about natural resources is needed in the management process. Remote sensing technology plays a significant role in the production of this geospatial information. Compared to terrestrial work, the analysis of larger areas with remote sensing techniques can be done on a shorter timescale and at lower cost. Image classification in remote sensing is one of the most popular methods used for the detection of forest and agricultural areas. However, the accuracy of classification changes according to …