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Articles 31 - 60 of 412
Full-Text Articles in Physical Sciences and Mathematics
M-Fdbscan: A Multicore Density-Based Uncertain Data Clustering Algorithm, Atakan Erdem, Taflan İmre Gündem
M-Fdbscan: A Multicore Density-Based Uncertain Data Clustering Algorithm, Atakan Erdem, Taflan İmre Gündem
Turkish Journal of Electrical Engineering and Computer Sciences
In many data mining applications, we use a clustering algorithm on a large amount of uncertain data. In this paper, we adapt an uncertain data clustering algorithm called fast density-based spatial clustering of applications with noise (FDBSCAN) to multicore systems in order to have fast processing. The new algorithm, which we call multicore FDBSCAN (M-FDBSCAN), splits the data domain into c rectangular regions, where c is the number of cores in the system. The FDBSCAN algorithm is then applied to each rectangular region simultaneously. After the clustering operation is completed, semiclusters that occur during splitting are detected and merged to …
Markovian Approach Applied To Reliability Modeling Of A Wind Farm, Mazaher Hajibashi, Akbar Ebrahimi
Markovian Approach Applied To Reliability Modeling Of A Wind Farm, Mazaher Hajibashi, Akbar Ebrahimi
Turkish Journal of Electrical Engineering and Computer Sciences
The exploitation of wind energy as a resource for generating electricity is going to make a leap forward. Large-scale wind farms (WFs) will be engaged with power systems in the near future and this will cause changes in the supply pattern. Wind speed has an intermittent behavior and the output power of a WF is highly variable, consistent with this fact. The Markov process could consider this characteristic of wind speed using the state transition rate probability matrix, an issue that is neglected when a probability distribution function is established to model the wind speed data. The adequacy indices of …
Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz
Design And Implementation Of A Programmable High-Voltage Impulse Measurement System, Serkan Dedeoğlu, Serhat Yilmaz
Turkish Journal of Electrical Engineering and Computer Sciences
High-voltage impulses (HVIs) are produced under laboratory conditions in order to emulate actual internal (switching) and external (lightning, thunderbolt) voltages. HVI resistance tests are essential to meet national and international standards on the production of electromechanical devices and materials, such as switchgears, and transformers that operate under these actual conditions. Accurate measurement of HVI is excessively difficult since the voltage level is so high, while the time parameters are relatively constricted. In this study, a reliable automatic HVI measuring and recording system, which accommodates a series of hardware and software designs in order to satisfy the constraints of the standards, …
Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic
Applications Of Wavelets And Neural Networks For Classification Of Power System Dynamics Events, Samir Avdakovic, Amir Nuhanovic, Mirza Kusljugic, Elvisa Becirovic
Turkish Journal of Electrical Engineering and Computer Sciences
This paper investigates the possibility of classifying power system dynamics events using discrete wavelet transform (DWT) and a neural network (NN) by analyzing one variable at a single network bus. Following a disturbance in the power system, it will propagate through the system in the form of low-frequency electromechanical oscillations (LFEOs) in a frequency range of up to 5 Hz. DWT allows the identification of components of the LFEO, their frequencies, and magnitudes. After determining the energy components' share of the analyzed signal using DWT and Parseval's theorem, the input data for the classification process using a NN are obtained. …
Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja
Observer-Based Controller For Current Mode Control Of An Interleaved Boost Converter, Shenbaga Lakshmi, Sree Renga Raja
Turkish Journal of Electrical Engineering and Computer Sciences
A state feedback control method for an interleaved boost power converter is designed, which, in turn, can achieve interleaved current sharing among parallel-connected converters. The state feedback control in the continuous time domain is derived using the pole placement technique and linear quadratic optimal method. The load estimator is designed by deriving a full-order state observer to ensure the robustness and optimality of the state feedback control and an observer-based controller (control law plus full-order state observer) is designed using the separation principle. The adopted control strategies achieve effective output voltage regulation, good dynamic stability, and reject disturbances. Extensive simulation …
Passive Ac Network Supplying The Integration Of Ccc-Hvdc And Vsc-Hvdc Systems, Ali Bidadfar, Mehrdad Abedi, Mehdi Karrari, Gevorg .Babamalek Gharehpetian, Sanaz Namayan Tavana
Passive Ac Network Supplying The Integration Of Ccc-Hvdc And Vsc-Hvdc Systems, Ali Bidadfar, Mehrdad Abedi, Mehdi Karrari, Gevorg .Babamalek Gharehpetian, Sanaz Namayan Tavana
Turkish Journal of Electrical Engineering and Computer Sciences
The integration of a capacitor-commutated converter (CCC) high-voltage direct current (HVDC) (CCC-HVDC) and voltage source converter (VSC) HVDC (VSC-HVDC) is proposed in this paper to supply entirely passive AC networks. The key point of this integration is the flat characteristic of the DC voltage of the CCC-HVDC, which provides the condition for the VSC to connect to the CCC DC link via a current regulator. The advantages of the proposed combined infeeding system are the requirement of only one DC line, and better dynamic responses. The structure of the proposed infeeding system, as well as its control system, is studied. …
Luenberger Observer-Based Sensor Fault Detection: Online Application To Dc Motor, Alkan Alkaya, İlyas Eker
Luenberger Observer-Based Sensor Fault Detection: Online Application To Dc Motor, Alkan Alkaya, İlyas Eker
Turkish Journal of Electrical Engineering and Computer Sciences
Fault detection and diagnosis (FDD) are very important for engineering systems in industrial applications. One of the most popular approaches is model-based fault detection. Recently, many techniques have been proposed in the FDD area. However, there are still very few reported applications or real-time implementations of the schemes. This paper presents online sensor FDD based on the model-based approach using a Luenberger observer and experimental application on a permanent magnet DC motor. Different kinds of faults are simulated on the motor and experiments are performed to detect the faults. The experimental results demonstrate that this approach could significantly detect the …
Design, Optimization, And Realization Of A Wire Antenna With A 25:1 Bandwidth Ratio For Terrestrial Communications, Korkut Yeği̇n
Design, Optimization, And Realization Of A Wire Antenna With A 25:1 Bandwidth Ratio For Terrestrial Communications, Korkut Yeği̇n
Turkish Journal of Electrical Engineering and Computer Sciences
Wire antennas can be made wideband if the antenna is loaded with passive elements and connected to a lossless matching network. However, realization of the load component values and matching network can easily become impractical. In this study, using only a surface mount and standard component values, antenna loads and a matching network are optimized using genetic algorithms. The optimized design achieves a 25:1 bandwidth ratio, from 20 MHz to 500 MHz, with a maximum voltage standing wave ratio (VSWR) of 3.5 and minimum system gain of --5 dBi. The antenna system gain at azimuth is taken as the objective …
How Do Hccmes Perform In Small Samples?, Mehmet Orhan, Esra Şi̇mşek
How Do Hccmes Perform In Small Samples?, Mehmet Orhan, Esra Şi̇mşek
Turkish Journal of Electrical Engineering and Computer Sciences
The purpose of this paper is to explore the performances of prominent and popular heteroscedasticity-consistent covariance matrix estimators (HCCMEs) in small samples. The HCCMEs are selected from the literature and their ability to estimate the true covariance matrix of the coefficient's vector is evaluated through simulation runs. We calculate the percentage difference between the expected value of the HCCME and the true covariance matrix to set a convenient stage to make the comparisons under several different regression settings. The main contribution of the paper is the inclusion of the HCCMEs that have been introduced into the literature recently. We report …
Privacy Preserving In Association Rules Using A Genetic Algorithm, Rahat Ali Shah, Sohail Asghar
Privacy Preserving In Association Rules Using A Genetic Algorithm, Rahat Ali Shah, Sohail Asghar
Turkish Journal of Electrical Engineering and Computer Sciences
Association rule mining is one of the data mining techniques used to extract hidden knowledge from large datasets. This hidden knowledge contains useful and confidential information that users want to keep private from the public. Similarly, privacy preserving data mining techniques are used to preserve such confidential information or restrictive patterns from unauthorized access. The pattern can be represented in the form of a frequent itemset or association rule. Furthermore, a rule or pattern is marked as sensitive if its disclosure risk is above a given threshold. Numerous techniques have been used to hide sensitive association rules by performing some …
A New Method For Extraction Of Speech Features Using Spectral Delta Characteristics And Invariant Integration, Hassan Farsi, Samana Kuhimoghadam
A New Method For Extraction Of Speech Features Using Spectral Delta Characteristics And Invariant Integration, Hassan Farsi, Samana Kuhimoghadam
Turkish Journal of Electrical Engineering and Computer Sciences
We propose a new feature extraction algorithm that is robust against noise. Nonlinear filtering and temporal masking are used for the proposed algorithm. Since the current automatic speech recognition systems use invariant-integration and delta-delta techniques for speech feature extraction, the proposed algorithm improves speech recognition accuracy appropriately using a delta-spectral feature instead of invariant integration. One of the nonenvironmental factors that reduce recognition accuracy is the vocal tract length (VTL), leading to a mismatch between the training and testing data. We can use the invariant-integration feature idea for decreasing the VTL effects. The aim of this paper is to provide …
Feature Selection On Single-Lead Ecg For Obstructive Sleep Apnea Diagnosis, Hüseyi̇n Gürüler, Mesut Şahi̇n, Abdullah Feri̇koğlu
Feature Selection On Single-Lead Ecg For Obstructive Sleep Apnea Diagnosis, Hüseyi̇n Gürüler, Mesut Şahi̇n, Abdullah Feri̇koğlu
Turkish Journal of Electrical Engineering and Computer Sciences
Many articles that appeared in the literature agreed upon the feasibility of diagnosing obstructive sleep apnea (OSA) with a single-lead electrocardiogram. Although high accuracies have been achieved in detection of apneic episodes and classification into apnea/hypopnea, there has not been a consensus on the best method of selecting the feature parameters. This study presents a classification scheme for OSA using common features belonging to the time domain, frequency domain, and nonlinear calculations of heart rate variability analysis, and then proposes a method of feature selection based on correlation matrices (CMs). The results show that the CMs can be utilized in …
Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel
Btsql: Nested Bitemporal Relational Database Query Language, Canan Atay, Abdullah Uz Tansel
Turkish Journal of Electrical Engineering and Computer Sciences
A nested bitemporal relational data model and its query language are implemented. The bitemporal atom (BTA) is the fundamental construct to represent temporal data and it contains 5 components: a value, the lower and upper bounds of valid time, and the lower and upper bounds of the recoding time. We consider 2 types of data structures for storing BTAs: 1) string representation and 2) abstract data-type representation. We also develop a preprocessor for translating a bitemporal structured query language (BtSQL) statement into standard SQL statements. The BtSQL includes the select, insert, delete, and update statements of the SQL, extended for …
Continuity Of Currents Across Neighboring Cells In Pmm Analysis Of Thin-Wire Grids, Sena Esen Bayer Keski̇n, Ahmet Ari̇f Ergi̇n
Continuity Of Currents Across Neighboring Cells In Pmm Analysis Of Thin-Wire Grids, Sena Esen Bayer Keski̇n, Ahmet Ari̇f Ergi̇n
Turkish Journal of Electrical Engineering and Computer Sciences
This article presents a new approach for the analysis of electromagnetic scattering from a rectangular wire mesh. In this sense, a basis function that considers the flow of a current from one cell to the next is proposed in light of Floquet's theorem. The proposed basis function enables the use of periodic method of moments in frequency-selective surfaces composed of thin wires in the case of a system having a connection with neighboring cells, such as thin-wire grids. The validity of the proposed solution approach is tested in 2 distinct cases (with and without a neighbor connection) for scattered fields. …
Bi Input-Extended Kalman Filter-Based Speed-Sensorless Control Of An Induction Machine Capable Of Working In The Field-Weakening Region, Remzi̇ İnan, Murat Barut
Bi Input-Extended Kalman Filter-Based Speed-Sensorless Control Of An Induction Machine Capable Of Working In The Field-Weakening Region, Remzi̇ İnan, Murat Barut
Turkish Journal of Electrical Engineering and Computer Sciences
This study introduces a novel bi input-extended Kalman filter (BI-EKF)-based speed-sensorless direct vector control (DVC) of an induction motor (IM). The proposed BI-EKF-based estimator includes online estimations of the stator stationary axis components of the stator currents, i_{s\alpha} and i_{s\beta}; stator stationary axis components of the rotor flux, \varphi_{r\alpha} and \varphi_{r\beta}; rotor angular velocity, \omega_m; stator resistance, R_s; rotor resistance, R_r; and load torque t_L, as well as the magnetizing inductance, L_m, by only supposing that the stator phase currents and voltages are measured. Thus, the speed-sensorless DVC of the IM with the inclusion of the proposed estimator is able …
Removing Random-Valued Impulse Noise In Images Using A Neural Network Detector, İlke Türkmen
Removing Random-Valued Impulse Noise In Images Using A Neural Network Detector, İlke Türkmen
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a new method using an artificial neural network to remove random-valued impulse noise (RVIN) in images. The inputs of the neural model used to detect the RVIN are formed using basic and related gradient values. The detection of the noisy pixels is realized in 3 phases using the proposed neural detector. In order to obtain a more robust detector, 2 different networks, which are trained with an artificial training image corrupted with high and low clutter densities, are used. The extensive simulation results show that the proposed method is significantly better than the compared filters in terms …
Robust Stability Of Linear Uncertain Discrete-Time Systems With Interval Time-Varying Delay, Mehmet Nur Alpaslan Parlakçi
Robust Stability Of Linear Uncertain Discrete-Time Systems With Interval Time-Varying Delay, Mehmet Nur Alpaslan Parlakçi
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a robust stability problem for linear uncertain discrete-time systems with interval time-varying delay and norm-bounded uncertainties. First, a necessary and sufficient stability condition is obtained by employing a well-known lifting method and switched system approach for nominal discrete-time delay systems. Both the stability method of checking the characteristic values inside the unit circle and a Lyapunov function-based stability result are taken into consideration. Second, a simple Lyapunov--Krasovskii functional (LKF) is selected, and utilizing a generalized Jensen sum inequality, a sufficient stability condition is presented in the form of linear matrix inequalities. Third, a novel LKF is proposed …
Perceptual Quality Evaluation Of Asymmetric Stereo Video Coding For Efficient 3d Rate Scaling, Nükhet Özbek, Gi̇zem Ertan, Oktay Karakuş
Perceptual Quality Evaluation Of Asymmetric Stereo Video Coding For Efficient 3d Rate Scaling, Nükhet Özbek, Gi̇zem Ertan, Oktay Karakuş
Turkish Journal of Electrical Engineering and Computer Sciences
In 3D perception, the binocular suppression of the human vision, perceiving high quality 3D video in the case of a view in higher quality, can be exploited in asymmetric stereo video coding for efficient 3D rate scaling. Hence, the best stereo rate-visual distortion performance may be gained by asymmetric coding, which is the reduction of the spatial and/or quantization resolution of the low-quality view, while keeping the high-quality view in full resolution. However, how to determine the level of asymmetry and what type of scaling should be chosen are still in question. In this work, we try to assess the …
Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky
Wireless Sensor Localization Using Enhanced Dv-Aoa Algorithm, Peter Brida, Juraj Machaj, Jozef Benikovsky
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we deal with the improvement of the positioning accuracy of distance vector (DV)-based positioning algorithms, which use angular information DV- angle of arrival (AoA). This algorithm belongs to an ad-hoc positioning system. We focus on the improvement of the algorithm and its enhanced version is presented. The angular information of particular nodes is obtained and processed by the original algorithm; however, the final position estimation is determined by the proposed novel algorithm using only a subset of all intersections. We assign weights to the individual intersections according to their positions and the positions of the RNs. For …
Impact Of Small-World Topology On The Performance Of A Feed-Forward Artificial Neural Network Based On 2 Different Real-Life Problems, Okan Erkaymaz, Mahmut Özer, Nejat Yumuşak
Impact Of Small-World Topology On The Performance Of A Feed-Forward Artificial Neural Network Based On 2 Different Real-Life Problems, Okan Erkaymaz, Mahmut Özer, Nejat Yumuşak
Turkish Journal of Electrical Engineering and Computer Sciences
Since feed-forward artificial neural networks (FFANNs) are the most widely used models to solve real-life problems, many studies have focused on improving their learning performances by changing the network architecture and learning algorithms. On the other hand, recently, small-world network topology has been shown to meet the characteristics of real-life problems. Therefore, in this study, instead of focusing on the performance of the conventional FFANNs, we investigated how real-life problems can be solved by a FFANN with small-world topology. Therefore, we considered 2 real-life problems: estimating the thermal performance of solar air collectors and predicting the modulus of rupture values …
Star-Crossed Cube: An Alternative To Star Graph, Nibedita Adhikari, Chitta Ranjan Tripathy
Star-Crossed Cube: An Alternative To Star Graph, Nibedita Adhikari, Chitta Ranjan Tripathy
Turkish Journal of Electrical Engineering and Computer Sciences
This paper introduces a new interconnection network topology called the star-crossed cube (SCQ). The SCQ is observed to be superior to other contemporary networks in terms of various topological parameters such as diameter, cost, average distance, and message traffic density. The various performance metrics of the proposed network, including cost effectiveness and time-cost effectiveness, are found to be better. The optimal routing and broadcasting algorithms for the new network are also presented. Embedding properties for the proposed network are also studied.
Source Microphone Identification From Speech Recordings Based On A Gaussian Mixture Model, Ömer Eski̇dere
Source Microphone Identification From Speech Recordings Based On A Gaussian Mixture Model, Ömer Eski̇dere
Turkish Journal of Electrical Engineering and Computer Sciences
Microphone identification is a specific type of media forensics that investigates whether it is possible to identify the source microphone from speech recordings. The main aim of this study is to find out which of the several feature extraction techniques are best suited to the source microphone identification systems. We perform microphone identification experiments with 16 different microphones using 3 datasets. In order to improve the results on the datasets, we also investigate the important parameters that may affect the microphone identification performance. Our experimental results show that the proposed method is comparable to the existing studies in a closed-set …
Correlation Analysis Between Surface Electromyography And Continuous-Wave Near-Infrared Spectroscopy Parameters During Isometric Exercise To Volitional Fatigue, Ömer Şayli̇, Ata Akin, Hasan Bi̇rol Çotuk
Correlation Analysis Between Surface Electromyography And Continuous-Wave Near-Infrared Spectroscopy Parameters During Isometric Exercise To Volitional Fatigue, Ömer Şayli̇, Ata Akin, Hasan Bi̇rol Çotuk
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the process of muscular fatigue was examined using surface electromyography (sEMG) and continuous-wave near-infrared spectroscopy (cw-NIRS) simultaneously during an isometric hand grip exercise at 50% and 75% of the maximal voluntary contraction (MVC), sustained until volitional fatigue. The mean frequency of the sEMG decreased during the whole exercise, whereas the root mean square had a tendency to increase. Oxyhemoglobin/deoxyhemoglobin concentration changes computed with cw-NIRS were found to exhibit a fast linear decrease/increase in the first 10--20 s of the exercise, the so-called fast phase, followed by a plateau-like slow phase. The change rates were higher at 75% …
Recurrent Wavelet Neural Network Control Of A Pmsg System Based On A Pmsm Wind Turbine Emulator, Chih Hong Lin
Recurrent Wavelet Neural Network Control Of A Pmsg System Based On A Pmsm Wind Turbine Emulator, Chih Hong Lin
Turkish Journal of Electrical Engineering and Computer Sciences
A recurrent wavelet neural network (NN)-controlled 3-phase permanent magnet synchronous generator system (PMSG), which is direct-driven by a permanent magnet synchronous motor (PMSM) based on a wind turbine emulator, is proposed to control the output values of a rectifier (or AC to DC power converter) and inverter (or DC to AC power converter) in this study. First, a closed-loop PMSM drive control based on a wind turbine emulator is designed to generate the maximum power for the PM synchronous generator (PMSG) system according to different wind speeds. Next, the rotor speed of the PMSG, the DC bus voltage, and the …
Discovery Of Hydrometeorological Patterns, Mete Çeli̇k, Fi̇li̇z Dadaşer Çeli̇k, Ahmet Şaki̇r Dokuz
Discovery Of Hydrometeorological Patterns, Mete Çeli̇k, Fi̇li̇z Dadaşer Çeli̇k, Ahmet Şaki̇r Dokuz
Turkish Journal of Electrical Engineering and Computer Sciences
Hydrometeorological patterns can be defined as meaningful and nontrivial associations between hydrological and meteorological parameters over a region. Discovering hydrometeorological patterns is important for many applications, including forecasting hydrometeorological hazards (floods and droughts), predicting the hydrological responses of ungauged basins, and filling in missing hydrological or meteorological records. However, discovering these patterns is challenging due to the special characteristics of hydrological and meteorological data, and is computationally complex due to the archival history of the datasets. Moreover, defining monotonic interest measures to quantify these patterns is difficult. In this study, we propose a new monotonic interest measure, called the hydrometeorological …
Simultaneous Identification And Correction Of Measurement And Branch Parameter Errors, Mehdi Ahmadi Jirdehi, Mehrdad Tarafdar Hagh, Kazem Zare
Simultaneous Identification And Correction Of Measurement And Branch Parameter Errors, Mehdi Ahmadi Jirdehi, Mehrdad Tarafdar Hagh, Kazem Zare
Turkish Journal of Electrical Engineering and Computer Sciences
The performance of the state estimation (SE) depends on the accuracy of the received measured data, as well as the parameter data of the power system. In this paper, a new algorithm is proposed for the simultaneous identification and correction of measurement and branch parameter errors (series and shunt admittances) in the power system SE problem. The proposed method uses Lagrange multipliers for the identification and correction of branch parameter errors without the need for a-priori specification of suspect parameter vectors. Erroneous measurements and branch parameter values can be corrected using the proposed method to estimate the measurement and branch …
Shuffled Frog Leaping Algorithm Optimization For Ac--Dc Optimal Power Flow Dispatch, Abolfazl Rahiminejad, Arash Alimardani, Behrooz Vahidi, Seyed Hossein Hosseinian
Shuffled Frog Leaping Algorithm Optimization For Ac--Dc Optimal Power Flow Dispatch, Abolfazl Rahiminejad, Arash Alimardani, Behrooz Vahidi, Seyed Hossein Hosseinian
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a simple-implemented and reliable AC--DC optimal power flow (OPF) is proposed. Although high-voltage direct current (HVDC) transmission lines are being increasingly used in power systems, new optimization algorithms such as evolutionary and memetic algorithms, which never stick in local minimum, so far have not been implemented in the AC--DC OPF problem. An evolutionary algorithm known as the shuffled frog leaping algorithm (SFLA) is proposed in this paper to solve the OPF dispatch in an AC--DC power system (including both high-voltage alternating current and HVDC transmission lines). The implementation of the AC--DC OPF with these kinds of methods …
Multifunction Converter Based On Lyapunov Function Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo
Multifunction Converter Based On Lyapunov Function Used In A Photovoltaic System, Trung Nhan Nguyen, An Luo
Turkish Journal of Electrical Engineering and Computer Sciences
The development of distributed generations (DGs) is essential to help solve energy crises and improve the reliability of electricity supplies. However, the involvement of a DG in a grid along with an increase of the nonlinear load will reduce the power quality. To solve this problem, we want the converter used in the DG to work flexibly, intelligently, and more accurately. To contribute to the improvement of quality of the DG, this paper proposes a multifunction converter (MFC) model. With the proposed model, the photovoltaic generator, which can be operated at harmonic suppression, and the power injection are more flexible …
Fuzzy Impedance And Force Control Of A Stewart Platform, Selçuk Ki̇zi̇r, Zafer Bi̇ngül
Fuzzy Impedance And Force Control Of A Stewart Platform, Selçuk Ki̇zi̇r, Zafer Bi̇ngül
Turkish Journal of Electrical Engineering and Computer Sciences
A new, simple, and effective control method is proposed for the position-based impedance and force control of a Stewart platform (SP). The control approach can be divided into 3 parts, namely position control in free space, impedance control in contact, and force control. An impedance filter is developed to achieve the desired behavior between the position and force. The gain of the filter is modified by a fuzzy logic proportional-integral-derivative controller. Kinematic and dynamic models of the SP are simulated in a MATLAB/Simulink environment. Several real-time experiments are conducted with the SP developed in our laboratory. The results of the …
Performance Evaluation Of The Wave Atom Algorithm To Classify Mammographic Images, Nebi̇ Gedi̇k, Ayten Atasoy
Performance Evaluation Of The Wave Atom Algorithm To Classify Mammographic Images, Nebi̇ Gedi̇k, Ayten Atasoy
Turkish Journal of Electrical Engineering and Computer Sciences
The most common type of cancer seen in women is breast cancer. To enable recovery from this severe disease, monitoring and early detection must be provided, and related precautions must be taken as a first step. During diagnosis, some cases may be overlooked due to fatigue and eyestrain, because the determination of abnormalities is a repetitive procedure. In this study, a computer-aided diagnosis (CAD) system, using the wave atom transform (WAT) algorithm and support vector machine (SVM), is proposed to evaluate mammography images. During the process, the region of interest (ROI) is defined before applying the method. The system includes …