An Optimized Buffer Insertion Algorithm With Delay-Power Constraints For Vlsi Layouts,
2017
TÜBİTAK
An Optimized Buffer Insertion Algorithm With Delay-Power Constraints For Vlsi Layouts, Chessda Uttraphan, Nasir Shaikh-Husin, Mohamed Khalil Hani
Turkish Journal of Electrical Engineering and Computer Sciences
We propose a grid-graph algorithm for interconnect routing and buffer insertion in nanometer VLSI layout designs. The algorithm is designed to handle multiconstraint optimizations, namely timing performance and power dissipation. The proposed algorithm is called HRTB-LA, which stands for hybrid routing tree and buffer insertion with look-ahead. In recent VLSI designs, interconnect delay has become a dominant factor compared to gate delay. The well-known technique to minimize the interconnect delay is by inserting buffers along the interconnect wires. However, the buffer itself consumes power and it has been shown that power dissipation overhead due to buffer insertions is significantly high. …
Modeling Lattice-Matched Inp-Based Multijunction Solar Cells,
2017
TÜBİTAK
Modeling Lattice-Matched Inp-Based Multijunction Solar Cells, Tuğba Selcen Navruz
Turkish Journal of Electrical Engineering and Computer Sciences
Currently, the multijunction solar cell structure gives the highest efficiency for photovoltaic solar cells. In this study, tandem, triple, and quadruple junction multijunction solar cell structures that include an InP subcell on InP substrate were investigated. A model that can calculate both the voltage-current characteristics and external quantum efficiency was demonstrated. The model gave fitted results with the experimental data for a single junction GaAs solar cell and a tandem solar cell that provides efficiency higher than 30%. The model was used to optimize the lattice-matched AlAsSb/InP tandem, AlAsSb/InP/InGaAsP triple, and AlAsSb/InP/InGaAsP/GaAsSb quadruple junction solar cell designs and the highest …
The Effect Of Fault Current Limiter Size And Type On Current Limitation In The Presence Of Distributed Generation,
2017
TÜBİTAK
The Effect Of Fault Current Limiter Size And Type On Current Limitation In The Presence Of Distributed Generation, Reza Mohammadi Chabanloo, Ehsan Mokhtarpour Habashi, Meysam Farrokhifar
Turkish Journal of Electrical Engineering and Computer Sciences
One of the effective mitigation solutions of the problems due to the penetration of distributed generation (DG) into the distribution network is a fault current limiter (FCL). Main attention is given to designs for resistive and inductive FCLs and others should meet the same requirements. At first in this paper network analysis is used to determine a suitable type of limiting impedance of a FCL in a distribution network in the presence of DG and then a comparative study of resistive, inductive, and complex FCLs is conducted to show the effect of size and type of FCL on the amplitude …
An Effective Empirical Approach To Voip Traffic Classification,
2017
TÜBİTAK
An Effective Empirical Approach To Voip Traffic Classification, Nazar Abbas Saqib, Yaqoot Shakeel, Moazzam Ali Khan, Hasan Mehmood, Muhammad Zia
Turkish Journal of Electrical Engineering and Computer Sciences
It is beneficial for telecommunication authorities and Internet service providers (ISPs) to classify and detect voice traffic. It can help them to block unsubscribed users from using their services, which saves them huge revenues. Voice packets can be detected easily, but it becomes complicated when the application or port information in the packet header is hidden due to some secure mechanism such as encryption. This work provides effective voice packet classification and detection based on behavioral and statistical analysis, which is independent of any application, security protocol, or encryption mechanism. First we have made initial assessments through packet feature analysis …
Nonlinear Acoustic Echo Cancellation Using An Adaptive Hammerstein Block Structure Based On A Generalized Basis Function,
2017
TÜBİTAK
Nonlinear Acoustic Echo Cancellation Using An Adaptive Hammerstein Block Structure Based On A Generalized Basis Function, Tuğba Özge Onur, Rifat Hacioğlu
Turkish Journal of Electrical Engineering and Computer Sciences
We investigated adaptive algorithms for a Hammerstein block structure in which a static nonlinear block and dynamic linear block are cascaded. The approach considered here is to use generalized orthonormal basis functions in a Hammerstein block structure by using fixed pole filter banks. We applied the normalized least mean square approach to the developed adaptive algorithm in order to acquire Hammerstein block structure parameters. Performance comparison of the proposed approach was investigated considering convergence speed and parametric complexity for acoustic echo cancellation application. The results indicated that in the developed algorithm along with appropriate selection of fixed poles, the algorithm …
A Novel Wound Field Flux Switching Machine With Salient Pole Rotor And Nonoverlapping Windings,
2017
TÜBİTAK
A Novel Wound Field Flux Switching Machine With Salient Pole Rotor And Nonoverlapping Windings, Faisal Khan, Erwan Sulaiman, Md Zarafi Ahmad
Turkish Journal of Electrical Engineering and Computer Sciences
A flux switching machine (FSM) with a segmented rotor and nonoverlapping windings is an attractive alternative for driving high torque density applications. However, a rotor with segments makes the motor less robust as well as difficult to be assembled, while a FSM with salient rotor and overlapping windings inherits high copper losses and less efficiency due to high coil volume. In this paper, a novel structure of FSM with nonoverlapping windings and salient rotor is proposed, making it different from the 10Slot-8Pole segmental and salient rotor FSM. Several design parameters defined in the rotor, armature coil, and field excitation coil …
Design And Analysis Of A Reduced Ultrawideband Band-Notched Band-Pass Filter,
2017
TÜBİTAK
Design And Analysis Of A Reduced Ultrawideband Band-Notched Band-Pass Filter, Navid Daryasafar, Mojtaba Tangaki, Mohammad Naser Moghaddasi, Ramezanali Sadeghzade
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper we intend to design a reduced ultrawideband band-pass filter using new models of coupled transmission lines. In this paper, by providing a new model of resonators, the bandwidth of band-pass filters (which are among the most crucial elements in communication systems) will be moderately increased, while their size and volume decreases. According to the change of their equations and consequent changes in basic parameters of these models, optimization and dependency among these parameters and also the frequency response of these filters will be developed to utilize notches in the pass-band, and a reduced ultrawideband band-pass filter with …
Universal And Stable Medical Image Generation For Tissue Segmentation (The Unistable Method),
2017
TÜBİTAK
Universal And Stable Medical Image Generation For Tissue Segmentation (The Unistable Method), Ihab Elaff, Ali El-Kemany, Mohammed Kholif
Turkish Journal of Electrical Engineering and Computer Sciences
Segmentation of medical images has been one of the most important research areas because of its impact in modeling and diagnosing the structure and the functions of various organs. The lack of unique solution for the segmentation problem of medical images is caused by the wide range of selections among different medical imaging modalities and clustering methods where each setting has its own estimates for solving this problem. The unistable method is a novel method that generates enhanced images with high contrast, which can reduce boundary overlap between different tissues. This is accomplished by fusion of different clustering maps, which …
Modeling And Analysis Of A Novel Dual Open-End Stator Windings Wound Rotor Synchronous Machine With Dampers,
2017
TÜBİTAK
Modeling And Analysis Of A Novel Dual Open-End Stator Windings Wound Rotor Synchronous Machine With Dampers, Abdelmonoem Nayli, Sami Guizani, Faouzi Ben Ammar
Turkish Journal of Electrical Engineering and Computer Sciences
This work presents a novel wound rotor synchronous machine with dampers with dual three-phase open-end stator windings. The aim of the proposed machine is to improve the power segmentation and the availability of the drive system. The mathematical model of this machine is presented in the Park reference frame. This machine is supplied by four 2-level inverters, where each inverter is dimensioned for quarter power of the machine. For comparison purposes, we use a double star synchronous machine fed by two 2-level inverters. Comparative simulation analysis using THD voltage, THD stator current, and torque undulation showed significant advantages of the …
Optimized Designs Of Reversible Arithmetic Logic Unit,
2017
TÜBİTAK
Optimized Designs Of Reversible Arithmetic Logic Unit, Ali Bolhassani, Majid Haghparast
Turkish Journal of Electrical Engineering and Computer Sciences
Reversible logic has emerged as a promising paradigm in various domains, such as low power VLSI design, quantum cellular automata, and nanotechnology-based systems. The arithmetic logic unit (ALU) is one of the main components of any central processing unit. In this paper we propose two new reversible ALUs using elementary quantum gates, with more functions compared to the existing designs. The results show that the proposed designs are better than the existing counterparts in terms of cost-metrics and the number of functions generated. The proposed reversible ALUs can be used in the implementation of quantum computers. All the designs are …
Advanced Probabilistic Power Flow Methodology For Power Systems With Renewable Resources,
2017
TÜBİTAK
Advanced Probabilistic Power Flow Methodology For Power Systems With Renewable Resources, Dinh Duong Le, Nhi Thi Ai Nguyen, Van Duong Ngo, Alberto Berizzi
Turkish Journal of Electrical Engineering and Computer Sciences
Renewable~resources have added additional uncertainty to power grids. Deterministic power flow does not provide sufficient information for power system calculation and analysis, since all sources of uncertainty are not taken into account. To handle uncertainties PPF has been introduced and used as an efficient tool. In this paper, we present a cumulant-based PPF approach that can account for various sources of uncertainty in power systems with renewable resources such as wind and photovoltaic energy. We also propose the use of a new methodology to estimate probability distribution for wind power output based on measured data. The proposed approach is carried …
Iris Nevus Diagnosis: Convolutional Neural Network And Deep Belief Network,
2017
TÜBİTAK
Iris Nevus Diagnosis: Convolutional Neural Network And Deep Belief Network, Oyebade Oyedotun, Adnan Khashman
Turkish Journal of Electrical Engineering and Computer Sciences
This work presents the diagnosis of iris nevus using a convolutional neural network (CNN) and deep belief network (DBN). Iris nevus is a pigmented growth (tumor) found in the front of the eye or around the pupil. It is seen that racial and environmental factors affect the iris color (e.g., blue, hazel, brown) of patients; hence, pigmented growths may be masked in the eye background or iris. In this work, some image processing techniques are applied to images to reinforce areas of interests in them, after which the considered classifiers are trained. We describe the automated diagnosis of iris nevus …
On The Application Of The Spectral Element Method In Electromagnetic Problems Involving Domain Decomposition,
2017
TÜBİTAK
On The Application Of The Spectral Element Method In Electromagnetic Problems Involving Domain Decomposition, Ibrahim Mahariq
Turkish Journal of Electrical Engineering and Computer Sciences
One of the challenges in electromagnetics is to solve electromagnetic fields originated from a radiating source or a scattering object in distances that largely exceed the dimensions of the source or scatterer. In this paper, domain decomposition based on the application reasoning of the perfectly matched layer (PML) is studied by the spectral element method (SEM) for the first time in order to solve near and far electromagnetic fields without requiring substantially computational resources. Scattering from a loss-free dielectric cylinder and radiated fields from a line source are the problems utilized for the purpose of numerical demonstration in two dimensions …
A Comparison Of Feature Extraction Techniques For Malware Analysis,
2017
TÜBİTAK
A Comparison Of Feature Extraction Techniques For Malware Analysis, Mohammad Imran, Muhammad Tanvir Afzal, Muhammad Abdul Qadir
Turkish Journal of Electrical Engineering and Computer Sciences
The manifold growth of malware in recent years has resulted in extensive research being conducted in the domain of malware analysis and detection, and theories from a wide variety of scientific knowledge domains have been applied to solve this problem. The algorithms from the machine learning paradigm have been particularly explored, and many feature extraction methods have been proposed in the literature for representing malware as feature vectors to be used in machine learning algorithms. In this paper we present a comparison of several feature extraction techniques by first applying them on system call logs of real malware, and then …
Traffic Density Estimation Via Kde And Nonlinear Ls,
2017
TÜBİTAK
Traffic Density Estimation Via Kde And Nonlinear Ls, Mi̇kai̇l Erdem, Mehmet Kemal Özdemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
With increasing population, the determination of traffic density becomes critical in managing urban city roads for safer driving and low carbon emissions. In this study, kernel density estimation is utilized in order to estimate traffic density more accurately when the speeds of vehicles are available for a given region. For the proposed approach, as a first step, the probability density function of the speed data is modeled by kernel density estimation. Then the speed centers from the density function are modeled as clusters. The cumulative distribution function of the speed data is then determined by Kolmogorov--Smirnov test, whose complexity is …
A 3d Simulation Of The Formation Of Primary Platelet Thrombi Based On A Hybrid Computational Model,
2017
TÜBİTAK
A 3d Simulation Of The Formation Of Primary Platelet Thrombi Based On A Hybrid Computational Model, Chaoqing Ma, Oubong Gwun
Turkish Journal of Electrical Engineering and Computer Sciences
Recently, the study of thrombosis simulation based on computational models has been one of the most popular research areas. In this paper, a 3D simulation method based on a hybrid model is proposed for platelet thrombus formation. The flow of platelets is modeled in a macroscale submodel using Navier--Stokes equations and the physiological processes such as adhesion and aggregation of platelets are modeled in a microscale submodel. In the adhesion and aggregation phases, the attraction of platelets due to blood coagulation factors (von Willebrand factor) is modeled using the external force, and the conversion from unstable aggregation to stable aggregation …
Performance Evaluation Of Simple Csrz-Qdpsk Transmitter Configurations For 20-Gbps Pon Applications,
2017
TÜBİTAK
Performance Evaluation Of Simple Csrz-Qdpsk Transmitter Configurations For 20-Gbps Pon Applications, Rimmya Chitravelu, Ganesh Madhan Muthu
Turkish Journal of Electrical Engineering and Computer Sciences
The performance of 1 and 2 Mach--Zehnder modulator (MZM)-based simple carrier suppressed return to zero differential quadrature phase shift keying (CSRZ-QDPSK) transmitters is analyzed in a 20 Gb/s single-mode fiber optic link. The link's performance under the transmitter schemes is evaluated by analyzing the received constellation, eye diagram, quality factor, and eye opening penalty (EOP) in a passive optical networks (PON) scenario. It is observed that the simple transmitter provides performance closer to the case of the standard 3 MZM CSRZ-QDPSK-based transmitter reported in the literature and implemented in experiments.
Assessing The Importance Of Features For Detection Of Hard Exudates In Retinal Images,
2017
TÜBİTAK
Assessing The Importance Of Features For Detection Of Hard Exudates In Retinal Images, Kemal Akyol, Baha Şen, Şafak Bayir, Hasan Basri̇ Çakmak
Turkish Journal of Electrical Engineering and Computer Sciences
Diabetes disrupts the operation of the eye and leads to vision loss, affecting particularly the nerve layer and capillary vessels in this layer by changes in the blood vessels of the retina.~Suddenly loss and blurred vision problems occur in the image, depending on the phase of the disease, called diabetic retinopathy. Hard exudates are one of the primary signs of diabetic retinopathy. Automatic recognition of hard exudates in retinal images can contribute to detection of the disease. We present an automatic screening system for the detection of hard exudates. This system consists of two main steps. Firstly, the features were …
A Clustering Approach Using A Combination Of Gravitational Search Algorithm And K-Harmonic Means And Its Application In Text Document Clustering, Mina Mirhosseini
Turkish Journal of Electrical Engineering and Computer Sciences
Data clustering is one of the most popular techniques of information management, which is used in many applications of science and engineering such as machine learning, pattern reorganization, image processing, data mining, and web mining. Different algorithms have been suggested by researchers, where the evolutionary algorithms are the best in data clustering and especially in big datasets. It is illustrated that GSA-KM, which is a combination of the gravitational search algorithm (GSA) and K-means (KM), is superior over some other comparative evolutionary methods. One of the drawbacks of this approach is dependency on the initial seeds. In this paper, a …
Comparison Of Using The Genetic Algorithm And Cuckoo Search For Multicriteria Optimisation With Limitation,
2017
TÜBİTAK
Comparison Of Using The Genetic Algorithm And Cuckoo Search For Multicriteria Optimisation With Limitation, Ryszard Klempka, Boguslaw Filipowicz
Turkish Journal of Electrical Engineering and Computer Sciences
The article presents an example of using two optimisation methods, a genetic algorithm and cuckoo search, to identify parameters of electric drive controllers using some quality criteria and by applying a limitation to the maximum values of signals in the controlled facility. The results for both optimisation methods are compared. The impact of the probability that the nest host discovers the laid eggs on the speed of finding the optimum solution is investigated.
