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Articles 147991 - 148020 of 302773

Full-Text Articles in Physical Sciences and Mathematics

Controlled Deposition Of Tin Oxide And Silver Nanoparticles Using Microcontact Printing, Joo C. Chan, Nicole Hannah-Moore, Shankar B. Rananavare Jan 2015

Controlled Deposition Of Tin Oxide And Silver Nanoparticles Using Microcontact Printing, Joo C. Chan, Nicole Hannah-Moore, Shankar B. Rananavare

Chemistry Faculty Publications and Presentations

This report describes extensive studies of deposition processes involving tin oxide (SnOx) nanoparticles on smooth glass surfaces. We demonstrate the use of smooth films of these nanoparticles as a platform for spatially-selective electroless deposition of silver by soft lithographic stamping. The edge and height roughness of the depositing metallic films are 100 nm and 20 nm, respectively, controlled by the intrinsic size of the nanoparticles. Mixtures of alcohols as capping agents provide further control over the size and shape of nanoparticles clusters. The distribution of cluster heights obtained by atomic force microscopy (AFM) is modeled through a modified …

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Phthalimide-Based Π-Conjugated Small Molecules With Tailored Electronic Energy Levels For Use As Acceptors In Organic Solar Cells, Arthur D. Hendsbee, Seth M. Mcafee, Jon-Paul Sun, Theresa M. Mccormick, Ian G. Hill, Gregory C. Welch Jan 2015

Phthalimide-Based Π-Conjugated Small Molecules With Tailored Electronic Energy Levels For Use As Acceptors In Organic Solar Cells, Arthur D. Hendsbee, Seth M. Mcafee, Jon-Paul Sun, Theresa M. Mccormick, Ian G. Hill, Gregory C. Welch

Chemistry Faculty Publications and Presentations

The design, synthesis, and characterization of seven phthalimide-based organic π-conjugated small molecules are reported. The new materials are based on a phthalimide–thiophene–CORE–thiophene–phthalimide architecture. The CORE units utilized were phthalimide (M2), diketopyrrolopyrrole (M3), isoindigo (M4), naphthalene diimide (M5), perylene diimide (M6), and difluorobenzothiadiazole (M7); they were specifically selected to progressively increase the electron affinity of the resulting compound. A small molecule with no core (M1) was synthesized for comparison. Each material was synthesized through optimized direct heteroarylation cross-coupling procedures using bench top solvents in air. Combinations of …

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Bandwidth Extension Of Narrowband Speech In Log Spectra Domain Using Neural Network, Sara Pourmohammadi, Mansour Vali, Mohsen Ghadyani Jan 2015

Bandwidth Extension Of Narrowband Speech In Log Spectra Domain Using Neural Network, Sara Pourmohammadi, Mansour Vali, Mohsen Ghadyani

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, there have been significant advances in communication technology, but speech signals still suffer from low perceived quality caused by bandwidth limitations of telephone networks. The bandwidth extension (BWE) approach adds high-frequency components of the speech signal to band-limited telephone speech and increases speech perception significantly. In this work, we develop a new method for representation of vocal tract filter coefficients using log of filter bank energy (LFBE) parameters as an alternative for mel-frequency cepstral coefficients (MFCCs). This approach is based on a strong correlation between the spectral components of low- and high-band spectrums. Furthermore, the performances of …

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Model-Based Test Case Prioritization Using Cluster Analysis: A Soft-Computing Approach, Ni̇da Gökçe, Fevzi̇ Belli̇, Mübari̇z Emi̇nli̇, Beki̇r Taner Di̇nçer Jan 2015

Model-Based Test Case Prioritization Using Cluster Analysis: A Soft-Computing Approach, Ni̇da Gökçe, Fevzi̇ Belli̇, Mübari̇z Emi̇nli̇, Beki̇r Taner Di̇nçer

Turkish Journal of Electrical Engineering and Computer Sciences

Model-based testing is related to the particular relevant features of the software under test (SUT) and its environment. Real-life systems often require a large number of tests, which cannot exhaustively be run due to time and cost constraints. Thus, it is necessary to prioritize the test cases in accordance with their importance as the tester perceives it, usually given by several attributes of relevant events entailed. Based on event-oriented graph models, this paper proposes an approach to ranking test cases in accordance with their preference degrees. For forming preference groups, events are clustered using an unsupervised neural network and fuzzy …

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Detection Of Microcalcification In Digitized Mammograms With Multistable Cellular Neural Networks Using A New Image Enhancement Method: Automated Lesion Intensity Enhancer (Alie), Levent Ci̇vci̇k, Burak Yilmaz, Yüksel Özbay, Gani̇me Di̇lek Emli̇k Jan 2015

Detection Of Microcalcification In Digitized Mammograms With Multistable Cellular Neural Networks Using A New Image Enhancement Method: Automated Lesion Intensity Enhancer (Alie), Levent Ci̇vci̇k, Burak Yilmaz, Yüksel Özbay, Gani̇me Di̇lek Emli̇k

Turkish Journal of Electrical Engineering and Computer Sciences

Microcalcification detection is a very important issue in early diagnosis of breast cancer. Generally physicians use mammogram images for this task; however, sometimes analyzing these images become a hard task because of problems in images such as high brightness values, dense tissues, noise, and insufficient contrast level. In this paper, we present a novel technique for the task of microcalcification detection. This technique consists of three steps. The first step is focused on removing pectoral muscle and unnecessary parts from the mammogram images by using cellular neural networks (CNNs), which makes this a novel process. In the second step, we …

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A Performance Comparison Of Conventional And Transverse Flux Linear Switched Reluctance Motors, Nuretti̇n Üstkoyuncu, Krishnan Ramu Jan 2015

A Performance Comparison Of Conventional And Transverse Flux Linear Switched Reluctance Motors, Nuretti̇n Üstkoyuncu, Krishnan Ramu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a comprehensive comparison between conventional (longitudinal flux) linear switched reluctance machines (CLSRMs) and transverse flux linear switched reluctance machines (TLSRMs) so as to enable engineers to choose a structure suitable for their applications. A commonly-used single-sided CLSRM and 4 different TLSRM structures are considered for the comparison. For a fair comparison of the 2 types of LSRMs, equal dimensions, including equal length and magnetomotive force, are applied as much as possible. The analytical approach and 3-dimensional finite element analysis (FEA) are employed to obtain the performance of these machines. It is proven analytically that the CLSRM has …

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Load Management In A Distributed Multimedia Streaming Environment Using A Fault-Tolerant Hierarchical System, Hadi̇ Işik Aybay, Mohammad Ahmed Shah Jan 2015

Load Management In A Distributed Multimedia Streaming Environment Using A Fault-Tolerant Hierarchical System, Hadi̇ Işik Aybay, Mohammad Ahmed Shah

Turkish Journal of Electrical Engineering and Computer Sciences

In contrast to text-only forms of communications, multimedia uses a combination of audiovisual means alongside textual modes of communication. Streaming multimedia is such multimedia that is constantly delivered by a provider of the multimedia to a client. In streaming multimedia the streamed content is continually presented to and received by the end user. Distributed multimedia systems (DMSs) deliver multimedia content to end-users by means of distributed multimedia databases and distributed information servers. These DMSs are designed to deliver multimedia content over a network. A fault-tolerant redundant hierarchy (Red-HI)-based load management policy for a distributed multimedia streaming system is proposed in …

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Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu Jan 2015

Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Transformers are an indispensable element in the transmission and distribution of electricity. While they are highly efficient, the increasing global demand for electrical energy has prompted efforts to improve their performance. No-load power losses constitute the majority of total losses within electrical energy distribution, especially when looking at load ratio. In recent years, some studies have found that no-load power losses of amorphous core transformers are less than those of laminated steel core transformers by as much as 60{\%} to 70{\%}. For this paper, we have manufactured an amorphous distribution transformer prototype rated 33 kV and 1 MVA. By quantifying …

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Active Filter Solutions In Energy Systems, Sabi̇r Rüstemli̇, Mehmet Sai̇t Cengi̇z Jan 2015

Active Filter Solutions In Energy Systems, Sabi̇r Rüstemli̇, Mehmet Sai̇t Cengi̇z

Turkish Journal of Electrical Engineering and Computer Sciences

Recent developments in power electronics have increased the usage of nonlinear loads in energy systems. With increases in the usage of semiconductor-sourced nonlinear loads, the adverse effects of harmonics-sensitive loads (e.g., protection control circuits and circuit breakers) have also increased. Generally, the negative effects of harmonics in power systems include the following: increased power losses; motor, generator, and transformer overheating; faulty operation of measurement and protection systems; lifetime shortening of electrical components; and parallel and series resonance problems. Therefore, harmonics has become a serious problem in current power electronics systems. However, harmonics can be reduced, particularly through drainage using filters. …

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Variable Charge/Discharge Time-Interval Control Strategy Of Bess For Wind Power Dispatch, Wei Chai, Zheng Li, Xu Cai Jan 2015

Variable Charge/Discharge Time-Interval Control Strategy Of Bess For Wind Power Dispatch, Wei Chai, Zheng Li, Xu Cai

Turkish Journal of Electrical Engineering and Computer Sciences

A variable charge/discharge time-interval ($T_{C/D})$ control strategy of a battery energy storage system (BESS) for wind power dispatch is proposed in this paper, aiming at: 1) extending the BESS life, 2) reducing the total BESS energy loss, and 3) increasing the dispatch tracking accuracy. A multifactor life model of a large-scale BESS containing four factors, charge/discharge rate, times, $T_{C/D}$, and temperature, is developed, which has taken into account the cell series/parallel effects and BESS operational characteristics. A comprehensive evaluation system including BESS aging level (BAL), energy loss index (ELI), and tracking inaccuracy index (TII) is proposed, and the relationships between …

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Performance Evaluation Of Three Phase Srf-Pll And Maf-Srf-Pll, Anirban Ghoshal, Vinod John Jan 2015

Performance Evaluation Of Three Phase Srf-Pll And Maf-Srf-Pll, Anirban Ghoshal, Vinod John

Turkish Journal of Electrical Engineering and Computer Sciences

Synchronous reference frame phase locked loop (SRF-PLL) is a well established technique used for maintaining synchronism of a grid connected VSI with an electric grid. Many methods of PLL are present in the literature to achieve improved performance under nonideal grid condition. These solutions are based on SRF-PLL structure along with some modification to achieve improved performance. It is observed that faster and better performance are achieved at the expense of more computations. Moving average filter (MAF) SRF-PLL structure is one such solution that consumes less resources and gives a reasonably fast response. In this work the performance of a …

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Capacity Allocation Of Hybrid Solar-Wind Energy System Based On Discrete Probabilistic Method, Chengjin Ye, Minxiang Huang Jan 2015

Capacity Allocation Of Hybrid Solar-Wind Energy System Based On Discrete Probabilistic Method, Chengjin Ye, Minxiang Huang

Turkish Journal of Electrical Engineering and Computer Sciences

Complementary renewable energies like wind and solar power may be more sufficient to satisfy reliability requirements. This paper proposes a quantitative capacity allocation method of a hybrid wind and solar energy system. First, discrete probability distributions are established to model the random factors including the volatility of power outputs and the failure of components. Then a multiobjective optimization model is formulated with objectives of minimization of the total investment, the nodal voltages violating limits probability, and power supply inadequacy probability. For the purpose of fast probability computing with a satisfactory precision degree, an innovative probabilistic load flow algorithm is introduced, …

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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 …

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Automatic Vehicle Classification Using Fast Neural Network And Classical Neural Network For Traffic Monitoring, Mahammad Abdul Hannan, Chew Teik Gee, Mohammad Saleh Javadi Jan 2015

Automatic Vehicle Classification Using Fast Neural Network And Classical Neural Network For Traffic Monitoring, Mahammad Abdul Hannan, Chew Teik Gee, Mohammad Saleh Javadi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces an automatic vehicle classification for traffic monitoring using image processing. In this technique the fast neural network (FNN) as a primary classifier and then the classical neural network (CNN) as a final classifier are applied to achieve high classification performance. The FNN gains a useful correlation between the input and the weighted neurons using a multilayer perceptron to provide detection with a high level of accuracy. The Fourier transform is used to speed up the procedure. In the CNN, a lighting normalization method is employed to reduce the effect of variations in illumination. The combination of the …

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Grounded Capacitor-Based New Floating Inductor Simulators And A Stability Test, Erkan Yuce, Sezai̇ Tokat, Hali̇l Alpaslan Jan 2015

Grounded Capacitor-Based New Floating Inductor Simulators And A Stability Test, Erkan Yuce, Sezai̇ Tokat, Hali̇l Alpaslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, two new floating inductor simulators (FISs), both using two differential difference current conveyors, are considered. The proposed FISs do not suffer from passive component matching constraints and employ a minimum number of passive elements. They use a grounded capacitor; accordingly, they are suitable for integrated circuit technology. They have good low- and high-frequency performances. Simulations are performed with the SPICE program to verify the claimed theory. Moreover, for the first FIS used in a second-order low-pass filter, a stability test is performed as an example.

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The Simulation And Production Of Glow Plugs Based On Thermal Modeling, Mustafa Saci̇d Endi̇z, Muci̇z Özcan, Mehmet Aki̇f Eri̇şmi̇ş, Mustafa Yağci, Hi̇dayet Günay Jan 2015

The Simulation And Production Of Glow Plugs Based On Thermal Modeling, Mustafa Saci̇d Endi̇z, Muci̇z Özcan, Mehmet Aki̇f Eri̇şmi̇ş, Mustafa Yağci, Hi̇dayet Günay

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, we present the thermal behavior of a glow plug examined with thermal impedance modeling. The circuit model is based on the analogy of thermal and electrical domains and expresses the glow plug used in diesel engines to preheat the air-diesel fuel mixture. In this study, the circuit design, implementation, and simulation of a glow plug for diesel engines are illustrated. In order to verify this thermal model, 2 different glow plugs are produced. The test results of the glow plugs produced in this study show complete agreement with the simulation results. It is thought that this circuit-based …

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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 …

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Color Texture Image Classification Based On Fractal Features And Extreme Learning Machine, Erkan Tanyildizi Jan 2015

Color Texture Image Classification Based On Fractal Features And Extreme Learning Machine, Erkan Tanyildizi

Turkish Journal of Electrical Engineering and Computer Sciences

Texture classification, especially color texture classification, is considered a significant step in segmentation and object classification. The property of color and texture is important for characterizing objects in natural scenes. Fractal dimension (FD) has many applications in the field of image compression and image segmentation. A series of FD features, such as mean, standard deviation, lacunarity, kurtosis, skewness, entropy, inverse difference moment, contrast, energy, dissimilarity, homogeneity, and maximum probability, are investigated for obtaining the maximum discrimination. In this manuscript, a methodology is proposed that is based on FD and an extreme learning machine for color texture classification. Performance of the …

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The Detailed Analysis Of Rate Equation Roots Of Bh-Laser Diode Using Volterra Series, Remzi̇ Yildirim, Ahmet Karaarslan Jan 2015

The Detailed Analysis Of Rate Equation Roots Of Bh-Laser Diode Using Volterra Series, Remzi̇ Yildirim, Ahmet Karaarslan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the rate equation analysis of a BH-laser diode was performed for output carrier density (N_o) using the zero-degree solution of the Volterra series. The carrier rate equation of the laser diode was analyzed in terms of input carrier density (N_i) and output carrier density modeling (N_i-N_o), with respect to the DC current (I_o). The polynomial root, which is obtained from the zero-degree solution (N_o) and limit values of I_o, was found. For the linear operation of the laser diode, the range of I_o current was also determined using a linearization approach and the maximum value of N_o.

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Efficient Id-Based Authentication And Key Agreement Protocols For The Session Initiation Protocol, Haci Hakan Kilinç, Yolguly Allaberdiyev, Tuğrul Yanik, Serdar Süer Erdem Jan 2015

Efficient Id-Based Authentication And Key Agreement Protocols For The Session Initiation Protocol, Haci Hakan Kilinç, Yolguly Allaberdiyev, Tuğrul Yanik, Serdar Süer Erdem

Turkish Journal of Electrical Engineering and Computer Sciences

In a widely deployed VoIP system tens of thousands of clients compete for the SIP proxy server's authentication service. SIP protocol implementations have to meet certain QoS and security requirements. In this study new ID-based protocols are proposed for the SIP authentication and key agreement protocols. These protocols minimize the use of expensive pairing functions but still resist notable attacks. The security of the proposed protocols are analyzed and demonstrated with security proofs based on the BJM security model. Finally, the performance overhead of the proposed protocols are compared to ID-based SIP authentication and key agreement protocols given in the …

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A Novel Adaptive Filter Design Using Lyapunov Stability Theory, Engi̇n Cemal Mengüç, Nuretti̇n Acir Jan 2015

A Novel Adaptive Filter Design Using Lyapunov Stability Theory, Engi̇n Cemal Mengüç, Nuretti̇n Acir

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach to design an adaptive filter using Lyapunov stability theory. The design procedure is formulated as an inequality constrained optimization problem. Lagrange multiplier theory is used as an optimization tool. Lyapunov stability theory is integrated into the constraint function to satisfy the asymptotic stability of the proposed filtering system. The tracking capability is improved by using a new analytical adaptation gain rate, which has the ability to adaptively adjust itself depending on a sequential tracking square error rate. The fast and robust convergence ability of the proposed algorithm is comparatively examined by simulation examples.

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A Fault Detection, Diagnosis, And Reconfiguration Method Via Support Vector Machines}, Rana Ortaç Kabaoğlu Jan 2015

A Fault Detection, Diagnosis, And Reconfiguration Method Via Support Vector Machines}, Rana Ortaç Kabaoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a fault detection, diagnosis, and reconfiguration method based on support vector machines. This method is appropriate for certain or predetermined faults and involves a fault detection and diagnosis unit and an online controller selection type reconfiguration mechanism. In this method, when a fault is detected and diagnosed by the fault detection and diagnosis unit, a suitable controller, which has been determined via an optimization algorithm in an off-line fashion, is activated to maintain proper closed-loop performance of the system in an on-line manner. In the detection, diagnosis, and reconfiguration stages of the method, support vector classification and …

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Mechanical Fault Detection In Permanent Magnet Synchronous Motors Using Equal Width Discretization-Based Probability Distribution And A Neural Network Model, Mehmet Akar, Mahmut Heki̇m, Umut Orhan Jan 2015

Mechanical Fault Detection In Permanent Magnet Synchronous Motors Using Equal Width Discretization-Based Probability Distribution And A Neural Network Model, Mehmet Akar, Mahmut Heki̇m, Umut Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper focuses on detecting the static eccentricity and bearing faults of a permanent magnet synchronous motor (PMSM) using probability distributions based on equal width discretization (EWD) and a multilayer perceptron neural network (MLPNN) model. In order to achieve this, the PMSM stator current values were measured in the cases of healthy, static eccentricity, and bearing faults for the conditions of three speeds and five loads. The data was discretized into several ranges through the EWD method, the probability distributions were computed according to the number of current values belonging to each range, and these distributions were then used as …

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Novel Congestion Control Algorithms For A Class Of Delayed Networks, Shoorangiz Shams Shamsabad Farahani, Mohammad Reza Jahed Motlagh, Mohammad Ali Nekoui Jan 2015

Novel Congestion Control Algorithms For A Class Of Delayed Networks, Shoorangiz Shams Shamsabad Farahani, Mohammad Reza Jahed Motlagh, Mohammad Ali Nekoui

Turkish Journal of Electrical Engineering and Computer Sciences

Time delays are often instability sources and give rise to undesired oscillation and performance degradation, so it is necessary to consider delay in general congestion control schemes. In this paper, a new system model for wireless sensor networks (WSNs) is established in discrete time, subsystems including delay are presented, and the overall model is achieved by blending these subsystems. For controller synthesis, common quadratic Lyapunov functions and a new approach based on nonquadratic Lyapunov functions are utilized, and a controller is designed to stabilize each subsystem. The controller synthesis results are expressed in terms of linear matrix inequalities. Moreover, the …

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An E-Nose-Based Indoor Air Quality Monitoring System: Prediction Of Combustible And Toxic Gas Concentrations, Beki̇r Mumyakmaz, Keri̇m Karabacak Jan 2015

An E-Nose-Based Indoor Air Quality Monitoring System: Prediction Of Combustible And Toxic Gas Concentrations, Beki̇r Mumyakmaz, Keri̇m Karabacak

Turkish Journal of Electrical Engineering and Computer Sciences

A system for monitoring and predicting indoor air quality level is proposed in this paper. The system comprises a computer with a monitoring program and a sensor cell, which has an array of metal oxide gas sensors along with a temperature and humidity sensor. The gas sensors in the cell have been chosen to detect only hydrogen, methane, and carbon monoxide gases. Methane was selected as a representative for indoor combustible gases, and carbon monoxide was used to represent indoor toxic gases. Hydrogen was used as an interfering (and also combustible) gas in the study. A number of experiments were …

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Dwmt Transceiver Equalization Using Overlap Fde For Downlink Adsl, Arsla Khan, Sobia Baig, Tabassum Nawaz Jan 2015

Dwmt Transceiver Equalization Using Overlap Fde For Downlink Adsl, Arsla Khan, Sobia Baig, Tabassum Nawaz

Turkish Journal of Electrical Engineering and Computer Sciences

Discrete wavelet multitone (DWMT) modulation is a wavelet transform based technique implemented using perfect reconstruction filter banks. It has been recently proposed for various wireline channels such as digital subscriber loops (DSLs) as a solution to the problems posed by a discrete multitone (DMT) transceiver including interblock interference (IBI) and lower spectral efficiency due to the employment of a cyclic prefix (CP) in the guard interval (GI) for DMT symbols. The greater side lobe attenuation offered by wavelet filter banks results in improved spectral containment and lower IBI in DWMT transceivers. However, no standard equalization technique exists for a DWMT …

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Performance Of Support Vector Regression Machines On Determining The Magnetic Characteristics Of The E-Core Transverse Flux Machine, Çi̇ğdem Gündoğan Türker, Feri̇ha Erfan Kuyumcu, Nurhan Türker Tokan Jan 2015

Performance Of Support Vector Regression Machines On Determining The Magnetic Characteristics Of The E-Core Transverse Flux Machine, Çi̇ğdem Gündoğan Türker, Feri̇ha Erfan Kuyumcu, Nurhan Türker Tokan

Turkish Journal of Electrical Engineering and Computer Sciences

The E-core transverse flux machine (ETFM) has major advantages with its different and unique structure in conventional electrical machines. It is a combination of transverse flux and reluctance principle. In this work, support vector regression machines (SVRMs) are used to obtain the magnetic characteristic parameters of the ETFM for the first time and it is compared with its artificial neural network model. The data for the training and testing of the SVRMs are obtained from experimental measurements. It is proven that SVRMs can conveniently be used in the modeling of the magnetic behaviors of highly nonlinear ETFM with better accuracy …

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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 …

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A Comparative Study Of Denoising Semg Signals, Ulvi̇ Başpinar, Volkan Yusuf Şenyürek, Bariş Doğan, Hüseyi̇n Selçuk Varol Jan 2015

A Comparative Study Of Denoising Semg Signals, Ulvi̇ Başpinar, Volkan Yusuf Şenyürek, Bariş Doğan, Hüseyi̇n Selçuk Varol

Turkish Journal of Electrical Engineering and Computer Sciences

Denoising of surface electromyography (sEMG) signals plays a vital role in sEMG-based mechatronics applications and diagnosis of muscular diseases. In this study, 3 different denoising methods of sEMG signals, empirical mode decomposition, discrete wavelet transform (DWT), and median filter, are examined. These methods are applied to 5 different levels of noise-added synthetic sEMG signals. For the DWT-based denoising technique, 40 different wavelet functions, 4 different threshold-selection-rules, and 2 threshold-methods are tested iteratively. Three different window-sized median filters are applied as well. The SNR values of denoised synthetic signals are calculated, and the results are used to select DWT and median …

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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 …

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