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Full-Text Articles in Physical Sciences and Mathematics

Simulation Of Locating Buried Objects Via Fringe Pattern-Based Measurements In An Optical Fiber Sensor-Integrated Continuous-Wave Ground-Penetrating Radar System, Asaf Behzat Şahi̇n, Hati̇ce Gonca Bulur Jan 2015

Simulation Of Locating Buried Objects Via Fringe Pattern-Based Measurements In An Optical Fiber Sensor-Integrated Continuous-Wave Ground-Penetrating Radar System, Asaf Behzat Şahi̇n, Hati̇ce Gonca Bulur

Turkish Journal of Electrical Engineering and Computer Sciences

A new ground-penetrating radar system that can determine the depth and position of a buried metal cylinder, which is the combination of an optical fiber sensor (OFS), continuous-wave transmitter, and optical communication link, is proposed and simulated in the MATLAB and Optiwave program packages. Employing an optical sensor instead of a standard radio frequency (RF) receiver offers the advantage of preventing electromagnetic interference along the sensor's main unit cable and lower amplification noise. In this paper, the electric field distribution at the OFS due to reflections from the soil surface and the buried object is obtained mathematically using Green's function. …


Estimating Facial Angles Using Radon Transform, Mohamad Amin Bakhshali, Mousa Shamsi Jan 2015

Estimating Facial Angles Using Radon Transform, Mohamad Amin Bakhshali, Mousa Shamsi

Turkish Journal of Electrical Engineering and Computer Sciences

Analysis of human facial images has become increasingly important due to its numerous applications. In this regard, extracting facial parameters is vital and various studies have been done in this field. Using these methods, different facial parameters such as the location of eyebrows, eye length, and nose angles are extracted. In this article, a robust and automatic method is introduced for determining facial angles from profile view images using the Radon transform. The Radon transform is a type of linear integration along a specific direction and angles play an important role in its performance. The proposed algorithm not only has …


Emg Classification In Obstructive Sleep Apnea Syndrome And Periodic Limb Movement Syndrome Patients By Using Wavelet Packet Transform And Extreme Learning Machine, Necmetti̇n Sezgi̇n Jan 2015

Emg Classification In Obstructive Sleep Apnea Syndrome And Periodic Limb Movement Syndrome Patients By Using Wavelet Packet Transform And Extreme Learning Machine, Necmetti̇n Sezgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Electromyogram (EMG) signals, measured at the skin surface, provide crucial access to the muscle tones of a body. Some diseases, such as obstructive sleep apnea syndrome (OSAS) and periodic limb movement syndrome (PLMS), are closely associated with the electrical activity of muscle tones. In this paper, a hybrid model containing wavelet packet transform (WPT) plus an extreme learning machine (ELM) was proposed to classify EMG signals in OSAS and PLMS patients. At first, the WPT was used to extract the features of the EMG signal, and then these features were fed to the ELM classifier. The mean classification accuracy of …


A Mobile And Web Application-Based Recommendation System Using Color Quantization And Collaborative Filtering, Fi̇dan Kaya, Gürel Yildiz, Adnan Kavak Jan 2015

A Mobile And Web Application-Based Recommendation System Using Color Quantization And Collaborative Filtering, Fi̇dan Kaya, Gürel Yildiz, Adnan Kavak

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a recommendation system based on a mobile and web application is proposed for indoor decoration. The main contribution of this work is to apply two-stage filtering using linear matching and collaborative filtering to make recommendations. In the mobile application part, the image of the medium captured by a mobile phone is analyzed using color quantization methods, and these color analysis results along with other user-defined parameters such as height, width, and type of the product are sent to the web server. In the web application part, a large data set is first filtered via linear matching in …


Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi Jan 2015

Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an active-reactive power control strategy for voltage source converters (VSCs) based on derivation of the direct and quadrature components of the VSC output current. The proposed method utilizes a multivariable proportional-integral controller and provides almost completely decoupled control capability of the active and reactive power with almost full disturbance rejection due to step changes in the power exchanged between the VSC and the grid. It also imposes fast transient response and zero steady-state error as compared to the conventional power control approaches. The applicability of the proposed power control strategy for providing the robust stability of the …


New Metrics For Clustering Of Identical Products Over Imperfect Data, Zeki̇ Yetgi̇n, Furkan Gözükara Jan 2015

New Metrics For Clustering Of Identical Products Over Imperfect Data, Zeki̇ Yetgi̇n, Furkan Gözükara

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces the concept of product identity-clustering based on new similarity metrics and new performance metrics for web-crawled products. Product identity-clustering is defined here as the clustering of identical products, e.g., for price comparison purposes. Products blindly crawled over web sources, e.g., online marketplaces, have different description formats, where the features describing the same products differ in both number and representation formats. This problem causes imperfect feature vectors, where the vectors are considered to be not uniform in length and structure, with the features of various data types (numeric, categorical), and unknown vector structures. Furthermore, the product information usually …


Optimal Integration Of Hybrid (Wind--Solar) System With Diesel Power Plant \Newline Using Homer, Muhammad Noman Siddique, Aftab Ahmad, Muhammad Kashif Nawaz, Syed Basit Ali Bukhari Jan 2015

Optimal Integration Of Hybrid (Wind--Solar) System With Diesel Power Plant \Newline Using Homer, Muhammad Noman Siddique, Aftab Ahmad, Muhammad Kashif Nawaz, Syed Basit Ali Bukhari

Turkish Journal of Electrical Engineering and Computer Sciences

Most energy worldwide is supplied through conventional energy sources, such as thermal, hydro, and nuclear. There have been serious energy crises in the last couple of years and so it is essential to consider renewable energy sources. This paper proposes a cost-effective solution for integrating a wind--solar system with an existing diesel power plant of a grid-connected site at Taxila, Pakistan. In the case of nonavailability of power from the grid, this diesel power plant acts as a standby system. Three cases were considered in this paper: 1) using the diesel power plant during load-shedding hours; 2) assisting the system …


Frequency-Adaptive Grid-Virtual-Flux Synchronization By Multiple Second-Order Generalized Integrators Under Distorted Grid Conditions, Yingjie Wang, Haiyuan Liu, Xuelong Han, Kangan Wang Jan 2015

Frequency-Adaptive Grid-Virtual-Flux Synchronization By Multiple Second-Order Generalized Integrators Under Distorted Grid Conditions, Yingjie Wang, Haiyuan Liu, Xuelong Han, Kangan Wang

Turkish Journal of Electrical Engineering and Computer Sciences

With some of the intermittent new energy and large nonlinear loads, grid voltage unbalance, harmonics, and frequency deviation are increasing year by year. The voltage source converter (VSC) is seriously affected by the various unexpected factors, and the presence of grid impedance makes the situation worse. In order to make the VSC track the nonideal grid quickly and accurately, this paper proposes a frequency-adaptive grid-virtual-flux synchronization by multiple second-order generalized integrators (MSOGI-GVFS). Key expressions of the MSOGI-GVFS and its frequency response characteristics are described in this paper. A second-order generalized integrator configured as a quadrature signal generator generates a specific-frequency …


Demand Response In The Day-Ahead Operation Of An Isolated Microgrid In The Presence Of Uncertainty Of Wind Power, Javad Olamaei, Saleh Ashouri Jan 2015

Demand Response In The Day-Ahead Operation Of An Isolated Microgrid In The Presence Of Uncertainty Of Wind Power, Javad Olamaei, Saleh Ashouri

Turkish Journal of Electrical Engineering and Computer Sciences

This paper explores the utilization of demand response in the day-ahead operation of an isolated microgrid in the presence of wind units. The operation of the network with high penetration wind units (i.e. uncertainty of wind units) is modeled as a unit commitment problem. In addition, electrical power storage is modeled in a daily power curve to decrease the effect of uncertainty in the wind units. Due to avoiding large-scale complexities and the deeper study effect of demand-side management on operations, the considered network is regarded as an isolated microgrid. The demand-side management is studied as demand shifting. The simulation …


Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n Jan 2015

Regulation Of Methane Gas Output From An Anaerobic Reactor System Using Moving Horizon $H_{\Infty }$ Control, Fatma Yildiz Taşcikaraoğlu, Şeref Naci̇ Engi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the moving horizon $\mathcal{H}_{\infty }$\textbf{ }control used for tracking a desired methane gas output from an anaerobic wastewater treatment reactor is compared with classical $\mathcal{H}_{\infty }$ control and a proportional-integral-derivative controller. The nonlinear system is first linearized around the set of equilibrium and operating points selected, and then the linear matrix inequalities required to comply with the constraints and guarantee the stability are constructed. Finally, the experimental results are obtained by implementing the control method in a MATLAB environment. It is concluded that moving horizon $\mathcal{H}_{\infty }$ control yields satisfactory results.


Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications, Gürsel Düzenli̇ Jan 2015

Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications, Gürsel Düzenli̇

Turkish Journal of Electrical Engineering and Computer Sciences

The reliability evaluation of MOS transistors is one of the most important subjects in device engineering and VLSI design. The down-scaling of device dimensions adversely affects device reliability and lifetime. Although different factors contribute to device reliability and lifetime, the most influential factor is hot-carrier degradation. Furthermore, hot-carrier degradation affects each application uniquely. In analog applications, hot-carrier degradation is more complex and diverse relative to digital applications. In this study, we improve the BSIM4 drain-current model to develop a hot-carrier degradation model that is suitable for both analog and digital applications. Our approach is readily applicable to all process technologies …


Multilevel Hybrid Cascade-Stack Inverter With Substantial Reduction In Switches Number And Power Losses, Mahdi Toopchi Khosroshahi, Ali Ajami, Ata Ollah Mokhberdoran, Mohammadreza Jannati Oskuee Jan 2015

Multilevel Hybrid Cascade-Stack Inverter With Substantial Reduction In Switches Number And Power Losses, Mahdi Toopchi Khosroshahi, Ali Ajami, Ata Ollah Mokhberdoran, Mohammadreza Jannati Oskuee

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a multilevel hybrid cascade-stack (HCS) converter. Recently, different new topologies for cascade-type converters have been suggested with the goal of reducing switch number, loss, switch PIV, etc. Meanwhile, output voltage steps increase, and the number of switches is predominately reduced in the suggested inverter in comparison to conventional cascade converters. Additionally, a reduction in the number of on-state switches in the introduced topology causes power loss and voltage drop to decrease. Firstly, the fundamental parts of inverter configuration are described. Afterwards, symmetric and asymmetric converter types are discussed. Simulation and experimental results for 11- and 23-level symmetric …


Multiagent-Based Simulation Of Simultaneous Electricity Market Auctions In Restructured Environment, Mohammad Farshad Jan 2015

Multiagent-Based Simulation Of Simultaneous Electricity Market Auctions In Restructured Environment, Mohammad Farshad

Turkish Journal of Electrical Engineering and Computer Sciences

In the restructured environment of the power industry, various commodities such as energy and operating reserves may be provided through simultaneous auctions. Prediction of market players' behavior in the auctions and simulation of the markets' environment can assist market decision-makers in evaluating specific policies before enforcing them in the real environment. Considering effects of the energy and varieties of reserve markets and also their interactions in the simulations is of high importance, which leads to more realistic simulation results. In this paper, an approach based on a multiagent system is proposed for simulating the simultaneous energy, spinning reserve, and replacement …


Opposition-Based Gravitational Search Algorithm Applied To Economic Power Dispatch Problems Consisting Of Thermal Units With Emission Constraints, Serdar Özyön, Celal Yaşar, Burhanetti̇n Durmuş, Hasan Temurtaş Jan 2015

Opposition-Based Gravitational Search Algorithm Applied To Economic Power Dispatch Problems Consisting Of Thermal Units With Emission Constraints, Serdar Özyön, Celal Yaşar, Burhanetti̇n Durmuş, Hasan Temurtaş

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a multiobjective environmental economic power dispatch problem has been converted into a single-objective optimization problem using the weighted sum method. For the solution of the converted problem, the gravitational search algorithm (GSA), which is one of the latest algorithms, has been used. In order to increase the performance of the GSA, opposite positioning quality has been added to the structure of the algorithm (OGSA). The obtained results show that the proposed algorithm has obtained better results and has provided a faster convergence. The 30-bus 6-generator test system has been selected for application of the OGSA. The transmission …


2d High-Frequency Forward-Looking Sonar Simulator Based On Continuous Surfaces Approach, Hakan Saç, Mehmet Kemal Leblebi̇ci̇oğlu, Gözde Akar Jan 2015

2d High-Frequency Forward-Looking Sonar Simulator Based On Continuous Surfaces Approach, Hakan Saç, Mehmet Kemal Leblebi̇ci̇oğlu, Gözde Akar

Turkish Journal of Electrical Engineering and Computer Sciences

Optical cameras give detailed images in clear waters. However, in dark or turbid waters, information coming from electro-optical sensors is insufficient for accurate scene perception. Imaging sonars, also known as acoustic cameras, can provide enhanced target details in these scenarios. In this paper, a computationally efficient 2D high-frequency, forward-looking sonar image simulator is presented. Stages and requirements of the image formation process are explained in detail. For the postprocessing of the returned sonar signals, a novel computation engine is proposed based on the geometric structures of the simulated surfaces. By treating all the continuous surfaces separately, the simulator is able …


Ethernet-Based Automation Network Systems Mobile Laboratory: A Case Study In Nonlinear Control Of Water Tank System, Levent Ucun, Onur Akbati, Gali̇p Cansever Jan 2015

Ethernet-Based Automation Network Systems Mobile Laboratory: A Case Study In Nonlinear Control Of Water Tank System, Levent Ucun, Onur Akbati, Gali̇p Cansever

Turkish Journal of Electrical Engineering and Computer Sciences

This paper studies an automation network configuration for the concept of a mobile laboratory establishment. The study also covers the design and implementation of a nonlinear controller for the water tank system as a case study. The design and establishment of the mobile laboratory is involved in CoNeT (Cooperative Network Training), a European Union-funded project that aims to design mobile laboratories for different uses in industrial network systems to be used for both application-oriented research and training. In addition to automation network communication and nonlinear controller design, this study also includes Modbus communication analysis and Ethernet traffic monitoring in an …


Design And Implementation Of Ir And Laser-Based Electronic Ciphering Systems, Feyzi̇ Akar, Osman Aşkin Jan 2015

Design And Implementation Of Ir And Laser-Based Electronic Ciphering Systems, Feyzi̇ Akar, Osman Aşkin

Turkish Journal of Electrical Engineering and Computer Sciences

This paper describes the design and implementation of infrared (IR) and laser-based electronic ciphering systems for use in both indoor and outdoor wireless remote control applications. To communicate between a user and a lock module in a secure way, the proposed systems utilize IR and laser frequencies instead of radio frequencies. Each proposed system has its specific security design. A new communication protocol is also generated, which is compatible for use with IR and laser technologies. The proposed electronic ciphering systems' prototypes are realized together with software and hardware components. They are instrumented using the peripheral interface controller series microcontrollers. …


A Novel Efficient Model For The Power Flow Analysis Of Power Systems, Amir Safdarian, Mahmud Fotuhi Firuzabad, Farrokh Aminifar Jan 2015

A Novel Efficient Model For The Power Flow Analysis Of Power Systems, Amir Safdarian, Mahmud Fotuhi Firuzabad, Farrokh Aminifar

Turkish Journal of Electrical Engineering and Computer Sciences

The overall system status calculated by power flow analysis is the most basic information used for all decisions taken by power system operators and planners. While conventional AC power flow solutions are computationally tractable, approximate DC models are employed in many applications, such as optimal power flow studies and unit commitment problems, mainly due to the linear nature of DC models. These models do not provide any information on the reactive power and voltage magnitude quantities and occasionally inaccurate results of the active power values. This paper presents an efficient power flow approach compromising both the conflicting aspects of speed …


Investigation Of Respiratory And Heart Rate Variability In Hypertensive Patients, Ramazan Aldemi̇r, Mahmut Tokmakçi Jan 2015

Investigation Of Respiratory And Heart Rate Variability In Hypertensive Patients, Ramazan Aldemi̇r, Mahmut Tokmakçi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, in order to examine the effect of respiration on heart rate variability (HRV), signal processing analyses were performed between the signal received from the periodic movement of the chest of respiration and the pulse plethysmograph (PPS) signal, providing the calculation of both the time and frequency behavior of HRV and also including pulse rate information at the same time. Respiration is used as the comparison parameter in both healthy subjects and in hypertensive patients, not only with the time and frequency components of the HRV, but also with the galvanic skin resistance simultaneously taken with body temperature …


Design Of A Novel Usb Crypto Bridge Device, Orhan Şengül Jan 2015

Design Of A Novel Usb Crypto Bridge Device, Orhan Şengül

Turkish Journal of Electrical Engineering and Computer Sciences

Information technologies have emerging use of portable drives. Hence, the readability and security of the content is at great risk in the event that it is lost or stolen. An effective solution to this issue is the use of removable disks in encrypted form. In this paper, a novel USB device that has cryptobridge capability is proposed.


A Hierarchic Approach Based On Swarm Intelligence To Solve The Traveling Salesman Problem, Mesut Gündüz, Mustafa Servet Kiran, Eren Özceylan Jan 2015

A Hierarchic Approach Based On Swarm Intelligence To Solve The Traveling Salesman Problem, Mesut Gündüz, Mustafa Servet Kiran, Eren Özceylan

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this paper is to present a new hierarchic method based on swarm intelligence algorithms for solving the well-known traveling salesman problem. The swarm intelligence algorithms implemented in this study are divided into 2 types: path construction-based and path improvement-based methods. The path construction-based method (ant colony optimization (ACO)) produces good solutions but takes more time to achieve a good solution, while the path improvement-based technique (artificial bee colony (ABC)) quickly produces results but does not achieve a good solution in a reasonable time. Therefore, a new hierarchic method, which consists of both ACO and ABC, is proposed …


Adaptive Network-Based Inference System Models On Multiband Patch Antenna Design, Erdem Demi̇rci̇oğlu, Murat Hüsnü Sazli, Orhan Şengül, Şehabeddi̇n Taha İmeci̇, Hakki Alparslan Ilgin Jan 2015

Adaptive Network-Based Inference System Models On Multiband Patch Antenna Design, Erdem Demi̇rci̇oğlu, Murat Hüsnü Sazli, Orhan Şengül, Şehabeddi̇n Taha İmeci̇, Hakki Alparslan Ilgin

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an adaptive network-based fuzzy inference system (ANFIS) for multiband microstrip patch antenna (MMPA) modeling is proposed. The MMPA includes a single patch with inverted L-shaped stubs on the edges. The antenna production process needs iterative runs of the electromagnetic (EM) simulator, fabricating and testing the simulated antenna to find the optimum geometry. Production processes (design, simulation, fabrication, and testing) and the cost computation time add to the overall manufacturing expenses. A computer-aided modeling approach using the ANFIS is developed and trained with data acquired from the EM simulators, Sonnet Suites and AWR AXIEM, and measurement data. The …


Enhancing Sliding Mode Control With Proportional Feedback And Feedforward: An Experimental Investigation On Speed Sensorless Control Of Pm Dc Motor Drives, Mehmet Dal Jan 2015

Enhancing Sliding Mode Control With Proportional Feedback And Feedforward: An Experimental Investigation On Speed Sensorless Control Of Pm Dc Motor Drives, Mehmet Dal

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the enhancement of sliding mode control (SMC) with the combined use of feedforward torque compensation and proportional error feedback control. The proposed enhancement is adapted to the control of permanent magnet (PM) DC motor drives by synthesis of the equivalent control equation augmented as proportional feedback and feedforward terms. A novel sliding function, introduced by utilizing the estimated load torque and the estimated rotor current, is examined and compared with another known sliding function obtained by nonideal differentiation of the estimated rotor speed. The significance of the proposed enhancements to SMC consists of the elimination of disturbance, …


Designing And Implementing A Reliable Thermal Monitoring System Based On The 1-Wire Protocol On Fpga For A Leo Satellite, Reza Omidi Gosheblagh, Karim Mohammadi Jan 2015

Designing And Implementing A Reliable Thermal Monitoring System Based On The 1-Wire Protocol On Fpga For A Leo Satellite, Reza Omidi Gosheblagh, Karim Mohammadi

Turkish Journal of Electrical Engineering and Computer Sciences

Thermal control and monitoring is one of the most important factors in the design of satellite systems. An appropriate thermal design should make sure that the satellite's sensitive components remain in their nominated range, even under the vacuum condition of outer space. To achieve this purpose, a reliable and stable monitoring system is required. This paper proposes a monitoring system based on the 1-wire protocol, which provides the reliability requirements in the sensor networking and bus controller sections. In the networking section, we outline some practical topologies and discuss on their complexity and reliability. Despite the fact that the point-to-point …


Discrete-Time Modeling Of Hamiltonian Systems, Yaprak Yalçin, Leyla Gören Sümer, Salman Kurtulan Jan 2015

Discrete-Time Modeling Of Hamiltonian Systems, Yaprak Yalçin, Leyla Gören Sümer, Salman Kurtulan

Turkish Journal of Electrical Engineering and Computer Sciences

The problem of discrete-time modeling of the lumped-parameter Hamiltonian systems is considered for engineering applications. Hence, a novel gradient-based method is presented, exploiting the discrete gradient concept and the forward Euler discretization under the assumption of the continuous Hamiltonian model is known. It is proven that the proposed discrete-time model structure defines a symplectic difference system and has the energy-conserving property under some conditions. In order to provide alternate discrete-time models, 3 different discrete-gradient definitions are given. The proposed models are convenient for the design of sampled-data controllers. All of the models are considered for several well-known Hamiltonian systems and …


Mras-Based Sensorless Speed Backstepping Control For Induction Machine, Using A Flux Sliding Mode Observer, Mohamed Moutchou, Ahmed Abbou, Hassan Mahmoudi Jan 2015

Mras-Based Sensorless Speed Backstepping Control For Induction Machine, Using A Flux Sliding Mode Observer, Mohamed Moutchou, Ahmed Abbou, Hassan Mahmoudi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an induction machine rotor speed and rotor flux control using a sensorless backstepping control scheme is discussed. The most interesting point of this technique is that it deals with the nonlinearity of a high-order system by using the virtual control variable to make this system simple, and thus the control outputs can be derived step by step through appropriate Lyapunov functions. To avoid the use of a mechanical sensor, the rotor speed estimation is made by an observer using the model reference adaptive system (MRAS) technique; in order to estimate rotor flux, a sliding mode observer is …


Temporal Logic Extension For Self-Referring, Nonexistence, Multiple Recurrence, And Anterior Past Events, Şadi̇ Evren Şeker Jan 2015

Temporal Logic Extension For Self-Referring, Nonexistence, Multiple Recurrence, And Anterior Past Events, Şadi̇ Evren Şeker

Turkish Journal of Electrical Engineering and Computer Sciences

This study focuses on the possible extensions of current temporal logics. In this study, 4 extensions are proposed: self-referring events, nonexisting events, multiple recurrence of events, and an improvement on anterior past events. Each of these extensions is on a different level of temporal logics. The main motivation behind the extensions is the temporal analysis of Turkish. Similar to temporal logic studies built on other natural languages, like French, Ukrainian, Italian, Korean, English, or Romanian, this is the first time that the Turkish language has been deeply questioned in the sense of computable temporal logic using the view of a …


Control Of Oxygen Excess Ratio In A Pem Fuel Cell System Using High-Order Sliding-Mode Controller And Observer, Seyed Mehdi Rakhtala, Abolfazl Ranjbar Noei, Reza Ghaderi, Elio Usai Jan 2015

Control Of Oxygen Excess Ratio In A Pem Fuel Cell System Using High-Order Sliding-Mode Controller And Observer, Seyed Mehdi Rakhtala, Abolfazl Ranjbar Noei, Reza Ghaderi, Elio Usai

Turkish Journal of Electrical Engineering and Computer Sciences

The main objective of this manuscript is to design a high-order sliding-mode observer to provide finite time estimation of unmeasurable states (x_4: oxygen mass, x_5: nitrogen mass) together with the oxygen excess ratio (ratio of the input oxygen flow to the reacted oxygen flow in the cathode). This is done by applying second-order sliding modes through either super twisting or suboptimal controllers to control the proton exchange membrane fuel cell's breathing. The estimated oxygen excess ratio is controlled in a closed-loop system using 2 distinct sliding-mode approaches: a cascaded super twisting controller and a single-loop suboptimal structure. Simulation results are …


A Robust Algorithm Based On A Failure-Sensitive Matrix For Fault Diagnosis Of Power Systems: An Application On Power Transformers, Yunus Bi̇çen, Faruk Aras Jan 2015

A Robust Algorithm Based On A Failure-Sensitive Matrix For Fault Diagnosis Of Power Systems: An Application On Power Transformers, Yunus Bi̇çen, Faruk Aras

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a robust algorithm for fault diagnosis of power system equipment based on a failure-sensitive matrix (FSM) is presented. The FSM is a dynamic matrix structure updated by multiple measurements (online) and test results (offline) on the systems. The algorithm uses many different artificial intelligence and expert system methods for adaptively detecting the location of faults, emerging failures, and causes of failures. In this algorithm, all data obtained from the power transformer, which have various nonlinear input and output parameters, are processed using the parallel matrix structure of the FSM to reach a global solution quickly. The parameters …


A Particle Swarm Optimization-Based Approach To Achieve Optimal Design And Operation Strategy Of Standalone Hybrid Energy Systems, Mahram Ghazvini, Ali Abbaspour Tehrani Fard, Mahmud Fotuhi Firuzabad Jan 2015

A Particle Swarm Optimization-Based Approach To Achieve Optimal Design And Operation Strategy Of Standalone Hybrid Energy Systems, Mahram Ghazvini, Ali Abbaspour Tehrani Fard, Mahmud Fotuhi Firuzabad

Turkish Journal of Electrical Engineering and Computer Sciences

As a cost-effective and reliable alternative to supply remote areas, standalone hybrid energy systems (HESs) are recently under investigation to address various concerns associated with technical, financial, and environmental issues. This paper presents a comprehensive algorithm that can simultaneously optimize the component size, operation strategy, and slope of the photovoltaic panels of a standalone HES using an improved variant of particle swarm optimization (PSO), designated as the passive congregation PSO. A new operation strategy is proposed based on the set points of the control system. The optimization algorithm determines the optimal values of the set points to efficiently optimize the …