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- Induction motor (2)
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Articles 1 - 30 of 74
Full-Text Articles in Physical Sciences and Mathematics
Line Detection With Adaptive Random Samples, Ali̇ Cafer Gürbüz
Line Detection With Adaptive Random Samples, Ali̇ Cafer Gürbüz
Turkish Journal of Electrical Engineering and Computer Sciences
This paper examines the detection of parameterized shapes in multidimensional noisy grayscale images. A novel shape detection algorithm utilizing random sample theory is presented. Although the method can be generalized, line detection is detailed. Each line in the image corresponds to a point in the line parameter space. The method creates hypothesis lines by randomly selecting parameter space points and tests the surrounding regions for acceptable linear features. The information obtained from each randomly selected line is used to update the parameter distribution, which reducesi the required number of random trials. The selected lines are re-estimated within a smaller search …
Rate 1 Space-Time And Space-Frequency Spreading Diversity Technique, Gökçe Hacioğlu, Ali̇ Gangal
Rate 1 Space-Time And Space-Frequency Spreading Diversity Technique, Gökçe Hacioğlu, Ali̇ Gangal
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a rate 1 transmitter diversity technique is proposed. The proposed technique uses spreading transform and space-time block coding (STBC) together. Space-time, space-frequency, and frequency diversity applications of the proposed technique are shown. The code matrix of the proposed technique can be designed systematically. The proposed technique needs the channel coefficients to stay constant over transmission of 2 rows of the coding matrix regardless of the size of the coding matrix or the diversity order. However, joint detection of the symbols is required for the proposed technique. We used computer simulations to compare our technique with the quasi-orthogonal …
Performance Evaluation Of Nonparametric Ica Algorithm For Fetal Ecg Extraction, Yusuf Sevi̇m, Ayten Atasoy
Performance Evaluation Of Nonparametric Ica Algorithm For Fetal Ecg Extraction, Yusuf Sevi̇m, Ayten Atasoy
Turkish Journal of Electrical Engineering and Computer Sciences
Fetal electrocardiograms (FECG) contain important indications about the health and condition of the fetus. In this respect, it is crucial to apply a robust algorithm to ECG data for extraction of the FECG signal. Most of the independent component analysis (ICA) algorithms used for this purpose rely on simple statistical models. Such algorithms can fail to separate desired signals when the assumed statistical model is inaccurate. Statistical models can be estimated accurately using kernel density estimation methods. Therefore, the kernel density estimation method was used in this paper for building an ICA algorithm (nonparametric ICA: NpICA) and the algorithm was …
Design And Development Of A Tilt-Wing Uav, Ertuğrul Çeti̇nsoy, Efe Sirimoğlu, Kaan Taha Öner, Cevdet Hançer, Mustafa Ünel, Mahmut Faruk Akşi̇t, İlyas Kandemi̇r, Kayhan Gülez
Design And Development Of A Tilt-Wing Uav, Ertuğrul Çeti̇nsoy, Efe Sirimoğlu, Kaan Taha Öner, Cevdet Hançer, Mustafa Ünel, Mahmut Faruk Akşi̇t, İlyas Kandemi̇r, Kayhan Gülez
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the mechanical and aerodynamic design, carbon composite production, hierarchical control system design and vertical flight tests of a new unmanned aerial vehicle (UAV), which is capable of VTOL (vertical takeoff and landing) like a helicopter and long range horizontal flight like an airplane, are presented. Real flight tests show that the aerial vehicle can successfully operate in VTOL mode. Kalman filtering is employed to obtain accurate roll and pitch angle estimations.
Ellipsoid Based L_2 Controller Design For Lpv Systems With Saturating Actuators, İbrahi̇m Beklan Küçükdemi̇ral, Levent Ucun, Yavuz Eren, Haluk Görgün, Gali̇p Cansever
Ellipsoid Based L_2 Controller Design For Lpv Systems With Saturating Actuators, İbrahi̇m Beklan Küçükdemi̇ral, Levent Ucun, Yavuz Eren, Haluk Görgün, Gali̇p Cansever
Turkish Journal of Electrical Engineering and Computer Sciences
This paper addresses the L_2 gain control problem for disturbance attenuation in Linear Parameter Varying (LPV) Systems having saturating actuators when the system is subjected to L_2 disturbances. In the presented method, saturating actuator is expressed analytically with a convex hull of some linear feedback which let us construct L_2 control problem via Linear Matrix Inequalities (LMIs) which are obtained by some ellipsoids. It is shown that the stability and disturbance rejection capabilities of the control system are all measured by means of these nested ellipsoids where the inner ellipsoid covers the initial conditions for states whereas the outer ellipsoid …
Spoiler Effects Reduction With Using Active Power Filter On A Direct Torque Controlled Induction Machine, İbrahi̇m Alişkan, Kayhan Gülez, Yusuf Altun
Spoiler Effects Reduction With Using Active Power Filter On A Direct Torque Controlled Induction Machine, İbrahi̇m Alişkan, Kayhan Gülez, Yusuf Altun
Turkish Journal of Electrical Engineering and Computer Sciences
Harmonics, which may be placed in electrical systems, have important effects on performance parameters of electrical motors. In this paper, effects of electrical power system voltage harmonics on torque position of induction motors are dealt with. System modeling with Pulse Width Modulation (PWM) type Active Power Filter (APF) is used for reducing these effects. APF, as a subsystem, is placed into torque control system entrance to save the control system and induction motor output torque. Motor outputs, that are before-after APF connections, are handed for understanding effects of voltage harmonics. Since APF design was based on voltage harmonics, Electromagnetic Interference …
Linear Motor For Multi--Car Elevators: Design And Position Measurement, Çağri Gürbüz, Ender Kazan, Ahmet Onat, Sandor Markon
Linear Motor For Multi--Car Elevators: Design And Position Measurement, Çağri Gürbüz, Ender Kazan, Ahmet Onat, Sandor Markon
Turkish Journal of Electrical Engineering and Computer Sciences
Multi-car elevator is an emerging technology consisting of two or more elevator cars moving independently in an elevator hoistway, which has become more appealing as building heights increase. In this paper, the design and drive methodologies for a linear motor driven multi-car elevator system with independently moving cars is introduced together with experimental results. Additionally, a safety method developed for the linear motor elevator and the conditions necessary for its proper operation are discussed. The new results introduced in this paper are in the areas of the design method of the linear motor for multi-car elevator system, and the preliminary …
Active Vibration Control Of Seismic Excited Structural System Using Lmi-Based Mixed H_2/H_{\Infty} State Feedback Controller, Hakan Yazici, Rahmi̇ Güçlü
Active Vibration Control Of Seismic Excited Structural System Using Lmi-Based Mixed H_2/H_{\Infty} State Feedback Controller, Hakan Yazici, Rahmi̇ Güçlü
Turkish Journal of Electrical Engineering and Computer Sciences
This paper is concerned with the active vibration control of a four-degree-of-freedom structure, which is effected by earthquake. To obtain desired time history and frequency responses for solution of active vibration control problem, Linear Matrix Inequality (LMI) based state-feedback mixed H_2/H_{\infty} controller is designed in this study. The time history of ground motion of the Kobe earthquake in 1995, which is a disturbance input, is applied to modeled structure. At the end of the study, the time history of the storey displacements, velocities and frequency responses of both controlled and uncontrolled cases are presented and results are discussed. Performance of …
Design And Implementation Of A Voice-Controlled Prosthetic Hand, Musa Hakan Asyali, Mustafa Yilmaz, Mahmut Tokmakçi, Kanber Sedef, Beki̇r Hakan Aksebzeci̇, Rohin Mittal
Design And Implementation Of A Voice-Controlled Prosthetic Hand, Musa Hakan Asyali, Mustafa Yilmaz, Mahmut Tokmakçi, Kanber Sedef, Beki̇r Hakan Aksebzeci̇, Rohin Mittal
Turkish Journal of Electrical Engineering and Computer Sciences
Current hand prostheses are mostly driven by electromyography (EMG) signal, and existing experiments have proved that multichannel EMG signal controls are not suitable due to early fatigue problems and high effort requirements to perform even simple activities. Therefore, in this study we present a new voice-controlled active hand prosthesis to perform several basic tasks. We first designed a novel multifingered prosthetic hand with the ability of picking up and releasing objects. The prosthetic hand employs 3 DC motors and gears to transfer motion to the linked iparts of the fingers. We used flexible thin-film resistive force sensors at the fingertips …
Adaptive Wiener-Turbo Systems With Jpeg & Bit Plane Compressions In Image Transmission, Ersi̇n Göse
Adaptive Wiener-Turbo Systems With Jpeg & Bit Plane Compressions In Image Transmission, Ersi̇n Göse
Turkish Journal of Electrical Engineering and Computer Sciences
In recent years, for transmission of 2D colored images over the fading channels, a new scheme has been denoted as ``adaptive Wiener-turbo systems with JPEG & bit plane compressions'' (AW-TSwJBC). In this paper, the performance of AW-TSwJBC is introduced over Rician and Rayleigh fading channels. We benefited from the neighborhood relation of pixels for each color plane by using a new iterative block, the ``adaptive Wiener-turbo'' scheme, which employs a turbo decoder, JPEG encoder/decoders, and adaptive Wiener filtering. In our approach, we could also alter compression ratios due to the importance of the image to be transferred. Based on the …
Asynchronous Signal Processing For Brain-Computer Interfaces, Seda Senay, Luis F. Chaparro, Mingui Sun, Robert Sclabassi, Aydin Akan
Asynchronous Signal Processing For Brain-Computer Interfaces, Seda Senay, Luis F. Chaparro, Mingui Sun, Robert Sclabassi, Aydin Akan
Turkish Journal of Electrical Engineering and Computer Sciences
Brain-computer interfaces (BCIs) provide a way to monitor and treat neurological diseases. An important application of BCIs is the monitoring and treatment of epilepsy, a neurological disorder characterized by recurrent unprovoked seizures, symptomatic of abnormal, excessive or synchronous neuronal activity in the brain. BCIs contain an array of sensors that gather and transmit data under the constrains of low-power and minimal data transmission. Asynchronous sigma delta modulators (ASDMs) are considered an alternative to synchronous analog to digital conversion. ASDMs are non-linear feedback systems that enable time-encoding of analog signals, from which the signal can be reconstructed. An efficient reconstruction of …
Applying The Finite Element Method To Analyze Predischarge Lightning Rods, Chin-Tsung Hsieh, Meng-Hui Wang, Cho-Yu Pan
Applying The Finite Element Method To Analyze Predischarge Lightning Rods, Chin-Tsung Hsieh, Meng-Hui Wang, Cho-Yu Pan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the finite element method is applied for analyzing 4 types of lightning rods in order to select the optimal lightning rod configuration. First, software is used to calculate the 2D protective coverage of different lighting rods, and 4 kinds of typical lightning rods are simulated in different conditions. The analyzed results are then applied for the selection of the optimal lighting rod and the frame of the lighting rod. The analyzed results would be useful for electrical engineers to design lightning rods that offer the most effective lighting protection; the simulated results are also useful for the …
A New, Improved Cmos Realization Of Cdta And Its Filter Applications, Firat Kaçar, Hulusi̇ Hakan Kuntman
A New, Improved Cmos Realization Of Cdta And Its Filter Applications, Firat Kaçar, Hulusi̇ Hakan Kuntman
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a high-performance current differencing transconductance amplifier (CDTA), a recently reported active element, especially suitable for analog signal processing applications. A high linearity CMOS configuration for a CDTA is made up of high linearity input and output stages. The proposed CDTA provides high output impedance at port X and excellent input/output current tracking. A biquad filter circuit was chosen as an application example in order to demonstrate the performance of the CDTA. PSpice simulation results using a TSMC 0.35-\mu m CMOS process model were included to verify the expected values.
Semi-Active H_{\Infty} Robust Control Of Six Degree Of Freedom Structural System Using Mr Damper, Şaban Çeti̇n, Seli̇m Si̇vri̇oğlu, Erkan Zergeroğlu, İsmai̇l Yüksek
Semi-Active H_{\Infty} Robust Control Of Six Degree Of Freedom Structural System Using Mr Damper, Şaban Çeti̇n, Seli̇m Si̇vri̇oğlu, Erkan Zergeroğlu, İsmai̇l Yüksek
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, H_{\infty} robust control is designed for vibration attenuation of six DOF structure using MR damper. A semi-active seismically excited, nonlinear structural system is modelled. The controller is designed for a reduced order model and applied to the full order model. The controller performance is verified experimentally. It is shown that the H_{\infty} controller performance is satisfactory to suppress the vibration of the structure despite the presence of uncertainties.
Electromagnetic Scattering From Layered Strip Geometries: The Method Of Moments Study With The Sinc Basis, Taner Oğuzer, Fadil Kuyucuoğlu, İbrahi̇m Avgin
Electromagnetic Scattering From Layered Strip Geometries: The Method Of Moments Study With The Sinc Basis, Taner Oğuzer, Fadil Kuyucuoğlu, İbrahi̇m Avgin
Turkish Journal of Electrical Engineering and Computer Sciences
Electromagnetic scattering from strips of layers is analyzed using the method of moments (MoM) for both polarizations in spatial domain with the sinc-type orthogonal sets as basis and testing functions. We exploited the sinc function's properties of exponential convergence, the orthogonality, easy convolution and better handling of singular kernels in MoM procedure resulting in fast performance and reasonable accuracy even in ordinary MoM treatment. We transferred the integral of the Hankel function multiplied by sinc functions to Hankel function introducing a slight error with large band width. We proved that this relative error during the generation of the main matrix …
A Logic Method For Efficient Reduction Of The Space Complexity Of The Attribute Reduction Problem, Mehmet Hacibeyoğlu, Fati̇h Başçi̇ftçi̇, Şi̇rzat Kahramanli
A Logic Method For Efficient Reduction Of The Space Complexity Of The Attribute Reduction Problem, Mehmet Hacibeyoğlu, Fati̇h Başçi̇ftçi̇, Şi̇rzat Kahramanli
Turkish Journal of Electrical Engineering and Computer Sciences
The goal of attribute reduction is to find a minimal subset (MS) R of the condition attribute set C of a dataset such that R has the same classification power as C. It was proved that the number of MSs for a dataset with n attributes may be as large as (_{n/2}^n) and the generation of all of them is an NP-hard problem. The main reason for this is the intractable space complexity of the conversion of the discernibility function (DF) of a dataset to the disjunctive normal form (DNF). Our analysis of many DF-to-DNF conversion processes showed that approximately …
A New Lvi Assisted Psfb Dc-Dc Converter, Ahmet Faruk Bakan
A New Lvi Assisted Psfb Dc-Dc Converter, Ahmet Faruk Bakan
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a new Phase Shifted Full Bridge (PSFB) Pulse Width Modulated (PWM) isolated dc-dc converter is proposed. In the proposed converter, resonant inductor is replaced with Linear Variable Inductor (LVI) that is controlled by output current. The soft switching operation range is increased and the dependency of ZVS operation on the load current is decreased. The required energy for ZVS operation at low current levels is obtained by means of the high value of the LVI. The value of LVI decreases approximately linearly with increasing current. At high current levels parasitic resonance and duty cycle loss are decreased. …
A Fuzzy Rule-Based System For Predicting The Live Weight Of Holstein Cows Whose Body Dimensions Were Determined By Image Analysis, Şaki̇r Taşdemi̇r, Abdullah Ürkmez, Şeref İnal
A Fuzzy Rule-Based System For Predicting The Live Weight Of Holstein Cows Whose Body Dimensions Were Determined By Image Analysis, Şaki̇r Taşdemi̇r, Abdullah Ürkmez, Şeref İnal
Turkish Journal of Electrical Engineering and Computer Sciences
The aim of this study was to determine the body measurement of Holstein cows through image analysis (IA) and to estimate their live weight (LW) by means of a fuzzy rule-based model using the body measurements. For this purpose, a photography environment was established at a dairy cattle farm where a large number of cows were kept. First, digital photographs of each animal were synchronously taken from different directions with Canon EOS 400D cameras. At the same time, body dimensions, namely wither height (WH), hip height (HH), body length (BL), and hip width (HW), of the cows were manually measured …
Self-Tuning Fuzzy Pd-Based Stiffness Controller Of A 3 \Times 3 Stewart Platform As A Man-Machine Interface, Vasfi̇ Emre Ömürlü, İbrahi̇m Yildiz
Self-Tuning Fuzzy Pd-Based Stiffness Controller Of A 3 \Times 3 Stewart Platform As A Man-Machine Interface, Vasfi̇ Emre Ömürlü, İbrahi̇m Yildiz
Turkish Journal of Electrical Engineering and Computer Sciences
Stewart Platform (SP) mechanism has wide application area on aerospace and manufacturing industry with its nonlinear structure allowing spatial motion capabilities. However, nonlinearities in the structure of the mechanism lead to complications in the dynamics of the system and result in complex control algorithms for dexterity in motion and force/torque feedback. Therefore, this paper aims to represent stiffness control by means of independent joint fuzzy-PD control algorithm with gain scheduling on an experimental 3 \times 3 SP parallel robotic mechanism to be used as a fly-by-wire flight control unit. Model and real system responses are compared employing stiffness control so …
Papr Reduction Using Artificial Bee Colony Algorithm In Ofdm Systems, Necmi̇ Taşpinar, Dervi̇ş Karaboğa, Mahmut Yildirim, Bahri̇ye Akay
Papr Reduction Using Artificial Bee Colony Algorithm In Ofdm Systems, Necmi̇ Taşpinar, Dervi̇ş Karaboğa, Mahmut Yildirim, Bahri̇ye Akay
Turkish Journal of Electrical Engineering and Computer Sciences
Partial transmit sequence (PTS) is an attractive scheme for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems, but its high computational complexity to find optimum phase factors is the main drawback. In this paper, we propose PTS based on an artificial bee colony (ABC) algorithm (ABC-PTS) for reducing the computational complexity of the PTS in the OFDM system. The ABC-PTS was compared to conventional PTS using a random search strategy (RS-PTS) and optimum PTS. In addition, the bit error rate (BER) performance of the ABC-PTS was shown when a high power amplifier (HPA) was used for …
Automatic Knowledge Extraction For Filling In Biography Forms From Turkish Texts, İlknur Pehli̇van, Zeynep Orhan
Automatic Knowledge Extraction For Filling In Biography Forms From Turkish Texts, İlknur Pehli̇van, Zeynep Orhan
Turkish Journal of Electrical Engineering and Computer Sciences
This study presents a method for building an automatic knowledge extraction system for filling in biography forms from Turkish texts. Several biographies are analyzed in order to choose the set of biography categories to be studied. The fields of the biography form to be created are also defined based on this analysis. Information extraction techniques are used for implementation. A separate testing platform is designed to evaluate the accuracy of the extracted data. Results of the testing platform have shown this study to be a promising process to be further developed especially for creating forms in the Turkish language.
Neuro-Fuzzy Soft-Switching Hybrid Filter For Impulsive Noisy Environments, Şaban Özer, Hasan Zorlu
Neuro-Fuzzy Soft-Switching Hybrid Filter For Impulsive Noisy Environments, Şaban Özer, Hasan Zorlu
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a new soft-switching hybrid filter based on a neuro-fuzzy network for impulsive noisy environments is proposed. The hybrid filter was built by combining an adaptive finite impulse response (FIR) filter, an adaptive weighted myriad (WMy) filter, and a soft-switching mechanism based on a neuro-fuzzy (NF) network. Performance of the hybrid filter was tested in \alpha-stable noisy situations and compared with adaptive FIR, WMy, and weighted median (WMd) filter performances. According to the simulation results; the proposed hybrid filter has better performance than the adaptive FIR, WMy, and WMd filters, and has the ability of effectively suppressing the …
Simulation Of Storage Time Versus Reverse Bias Current For P^+N And Pin Diodes, Mehmet Serhat Keserli̇oğlu, Hasan Hüseyi̇n Erkaya
Simulation Of Storage Time Versus Reverse Bias Current For P^+N And Pin Diodes, Mehmet Serhat Keserli̇oğlu, Hasan Hüseyi̇n Erkaya
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the reverse-recovery behaviors of pin and p^+n diodes were simulated as a function of the reverse current and carrier lifetime. For this purpose, a 1-D simulation program was written to solve the semiconductor equations. MatLab partial differential equation solver was used. The reverse recovery response of pin and p^+n diodes was obtained for various values of a resistor in series and of carrier lifetime. The transient response for voltage and current was determined.
Co-Occurrence Matrix And Its Statistical Features As A New Approach For Face Recognition, Alaa Eleyan, Hasan Demirel
Co-Occurrence Matrix And Its Statistical Features As A New Approach For Face Recognition, Alaa Eleyan, Hasan Demirel
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a new face recognition technique is introduced based on the gray-level co-occurrence matrix (GLCM). GLCM represents the distributions of the intensities and the information about relative positions of neighboring pixels of an image. We proposed two methods to extract feature vectors using GLCM for face classification. The first method extracts the well-known Haralick features from the GLCM, and the second method directly uses GLCM by converting the matrix into a vector that can be used in the classification process. The results demonstrate that the second method, which uses GLCM directly, is superior to the first method that …
Determining Wave Propagation Characteristics Of Mv Xlpe Power Cable Using Time Domain Reflectometry Technique, Ghulam Murtaza Hashmi, Ruslan Papazyan, Matti Lehtonen
Determining Wave Propagation Characteristics Of Mv Xlpe Power Cable Using Time Domain Reflectometry Technique, Ghulam Murtaza Hashmi, Ruslan Papazyan, Matti Lehtonen
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the wave propagation characteristics of single-phase medium voltage (MV) cross-linked polyethylene (XLPE) power cable are determined using time domain reflectometry (TDR) measurement technique. TDR delivers the complex propagation constant (attenuation and phase constant) of lossy cable transmission line as a function of frequency. The frequency-dependent propagation velocity is also determined from the TDR measurements through the parameters extraction procedure. The calibration of the measuring system (MS) is carried-out to avoid the effect of multiple reflections on the accuracy of measurements. The results obtained from the measurements can be used to localize the discontinuities as well as the …
New Srco With Explicit Current-Mode Output Using Two Ccs And Grounded Capacitors, D R. Bhaskar, Kasim K. Abdalla, Raj Senani
New Srco With Explicit Current-Mode Output Using Two Ccs And Grounded Capacitors, D R. Bhaskar, Kasim K. Abdalla, Raj Senani
Turkish Journal of Electrical Engineering and Computer Sciences
A new Grounded-Capacitor Single Resistance Controlled Sinusoidal Oscillator (SRCO) with explicit current output using two Current Conveyors (CCs) and five passive elements is presented. The proposed circuit offers (i) independent control of condition of oscillation and frequency of oscillation, (ii) low active and passive sensitivities, (iii) use of both the grounded capacitors (suitable for IC implementation) and (iv) reasonably good frequency stability. The workability of the proposed configuration has been confirmed by the PSPICE simulations.
Design And Ground Plane Optimization Of A Cpw-Fed Ultra-Wideband Antenna, Mohammed Al-Husseini, Ali Ramadan, Youssef Tawk, Ali El-Hajj, Karim Y. Kabalan
Design And Ground Plane Optimization Of A Cpw-Fed Ultra-Wideband Antenna, Mohammed Al-Husseini, Ali Ramadan, Youssef Tawk, Ali El-Hajj, Karim Y. Kabalan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, an ultra-wideband antenna based on an egg-shaped conductor and a co-planar waveguide (CPW) feed is presented. The ground plane incorporates an egg-shaped slot with parametrized center and dimensions. By resizing the slot and moving its center, a slotted or a partial ground can be obtained. Based on this configuration, a parametric study that aims at achieving the best ultra-wideband (UWB) response of the antenna is done. The study shows that an excellent UWB response is achieved for a certain ground slot size, beyond which the response starts to degrade. However, as the slot size tends to infinity, …
Cognitive And Encrypted Communications: State Of The Art And A New Approach For Frequency-Agile Filters, Yahya Lakys, Balwant Godara, Alain Fabre
Cognitive And Encrypted Communications: State Of The Art And A New Approach For Frequency-Agile Filters, Yahya Lakys, Balwant Godara, Alain Fabre
Turkish Journal of Electrical Engineering and Computer Sciences
Several communication techniques are investigated in the first part of this paper: software radio, cognitive radio and encrypted communications. State of the art of research on agile and reconfigurable filters, passive as well as active, necessary for transceivers is then made and various tables for comparison are given. In the third part, a new theory for a 2^{nd}-order frequency-agile filter is introduced. The center frequency of the filter is proportional to the gain of a feedback amplifier and thus can be tuned over a wide frequency range. This new theory is thereafter generalized to the n^{th}-class leading to a center …
An Extended Component-Based Reliability Model For Protective Systems To Determine Routine Test Schedule, Amir Abbarin, Mahmoud Fotuhi Firuzabad, Aydoğan Özdemi̇r
An Extended Component-Based Reliability Model For Protective Systems To Determine Routine Test Schedule, Amir Abbarin, Mahmoud Fotuhi Firuzabad, Aydoğan Özdemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel approach for evaluating the reliability of protective systems taking into account its components reliability. In this paper, a previously proposed extended model is used for a directional over-current scheme. In the extended model, the impacts of individual protective components are taken into account. An optimum routine test schedule is determined for each protective component as a separate unit. A comparison is made to show that the proposed approach has excellence over conventional routine test inspections. Impacts of factors such as circuit breaker inadvertent opening, required time for performing routine test inspections, human mistakes and self-checking …
Remote Mutual Authentication And Key Agreement Scheme Based On Elliptic Curve Cryptosystem, Eunjun Yoon
Remote Mutual Authentication And Key Agreement Scheme Based On Elliptic Curve Cryptosystem, Eunjun Yoon
Turkish Journal of Electrical Engineering and Computer Sciences
Remote mutual authentication is an important part of security, along with confidentiality and integrity, for systems that allow remote access over untrustworthy networks, like the Internet. In 2006, Shieh-Wang pointed out the weakness of Juang's remote mutual authentication scheme using smart card and further proposed a novel remote user authentication scheme using smart card. However, this paper demonstrates that Shieh-Wang's scheme still does not provide perfect forward secrecy and is vulnerable to a privileged insider's attack. We also present an improved scheme based on the Elliptic Curve Diffie-Hellman problem (ECDHP) and secure one-way hash function, in order to isolate such …