Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 100

Full-Text Articles in Physical Sciences and Mathematics

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş Jan 2012

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a modified particle swarm algorithm to handle multiobjective optimization problems. In multiobjective PSO algorithms, the determination of Pareto optimal solutions depends directly on the strategy of assigning a best local guide to each particle. In this work, the PSO algorithm is modified to assign a best local guide to each particle by using minimum angular distance information. This algorithm is implemented to determine field-effect transistor (FET) model elements subject to the Pareto domination between the scattering parameters and operation bandwidth. Furthermore, the results are compared with those obtained by the nondominated sorting genetic algorithm-II. FET models are …


Automatic Tracking System For Weather Satellite Image Reception, Wassila Leila Rahal, Noureddine Benabadji, Ahmed Hafid Belbachir Jan 2012

Automatic Tracking System For Weather Satellite Image Reception, Wassila Leila Rahal, Noureddine Benabadji, Ahmed Hafid Belbachir

Turkish Journal of Electrical Engineering and Computer Sciences

We present a tracking ground system for low Earth-orbiting (LEO) satellite image reception composed of a software part and a material part. The developed prediction software (LAAR-TRACK) ensures an efficient satellite orbit determination. It is based on the simplified general perturbations model (SGP4) used by the North American Aerospace Defense Command for generating orbital elements. LAAR-TRACK gives the azimuth and the elevation needed for the antenna to signal, in real time, LEO satellites during their passage above the ground receiving station. The software is loaded on a computer directly connected, via the parallel port, to the tracking interface that we …


Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar Jan 2012

Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar

Turkish Journal of Electrical Engineering and Computer Sciences

The fast changes and developments in the world's economy have substantially increased energy consumption. Consequently, energy planning has become more critical and important. Forecasting is one of the main tools utilized in energy planning. Recently developed computational techniques such as genetic algorithms have led to easily produced and accurate forecasts. In this paper, a natural gas consumption forecasting methodology is developed and implemented with state-of-the-art techniques. We show that our forecasts are quite close to real consumption values. Accurate forecasting of natural gas consumption is extremely critical as the majority of purchasing agreements made are based on predictions. As a …


Cascade Fuzzy Logic Control Of A Single-Link Flexible-Joint Manipulator, İsmai̇l Hakki Akyüz, Zafer Bi̇ngül, Selçuk Ki̇zi̇r Jan 2012

Cascade Fuzzy Logic Control Of A Single-Link Flexible-Joint Manipulator, İsmai̇l Hakki Akyüz, Zafer Bi̇ngül, Selçuk Ki̇zi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and control of a single-link flexible-joint robot manipulator. A cascade fuzzy logic controller (FLC) was used to remove link vibrations and to obtain fast trajectory tracking performance. The cascade FLC structure includes 3 different FLCs. The input variables of the first and the second FLCs are the motor rotation angle error, its derivative, and the end-point deflection error its derivative, respectively. The outputs of these controllers are the inputs of the third FLC, which yields the control signal to the flexible robot arm. All of the FLCs were embedded in a DS1103 real-time control board. …


Effects Of Diacritics On Turkish Information Retrieval, Adi̇l Alpkoçak, Meltem Ceylan Jan 2012

Effects Of Diacritics On Turkish Information Retrieval, Adi̇l Alpkoçak, Meltem Ceylan

Turkish Journal of Electrical Engineering and Computer Sciences

We investigate the effects of improper use of diacritics in the Turkish alphabet on information retrieval. A diacritic is simply a supplementary sign added to a letter to change the sound value of the letter, and the Turkish alphabet has 5 special letters derived from Latin by adding different diacritics. The statistical analysis performed in this study shows that retrieval performance significantly decreases when documents and queries contain letters with different forms, such that documents consist of letters with diacritics while queries consist of standard Latin letters and vice versa. In order to tackle this challenge, we propose 3 approaches: …


Stability Of The Adaptive Fading Extended Kalman Filter With The Matrix Forgetting Factor, Cenker Bi̇çer, Esi̇n Köksal Babacan, Levent Özbek Jan 2012

Stability Of The Adaptive Fading Extended Kalman Filter With The Matrix Forgetting Factor, Cenker Bi̇çer, Esi̇n Köksal Babacan, Levent Özbek

Turkish Journal of Electrical Engineering and Computer Sciences

The extended Kalman filter is extensively used in nonlinear state estimation problems. As long as the system characteristics are correctly known, the extended Kalman filter gives the best performance. However, when the system information is partially known or incorrect, the extended Kalman filter may diverge or give biased estimates. An extensive number of works has been published to improve the performance of the extended Kalman filter. Many researchers have proposed the introduction of a forgetting factor, both into the Kalman filter and the extended Kalman filter, to improve the performance. However, there are 2 fundamental problems with this approach: the …


A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan Jan 2012

A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel hybrid approach for detection of power quality (PQ) disturbances. The proposed hybrid algorithm is based on applications of principle component analysis, discrete wavelet transform, and fast Fourier transform on voltage and current waveforms. The proposed PQ monitoring (PQM) software uses 3-phase voltage and current signals in order to detect possible power disturbances such as voltage sag, flicker, harmonics, transients, DC component, and electromagnetic interference. The test results demonstrate the potential of the proposed hybrid technique for PQM andPQ assessment.


Characterization Of A Total Power Radiometer, Murat Celep, Şenel Yaran, Yakup Gülmez, Ari̇f Dolma Jan 2012

Characterization Of A Total Power Radiometer, Murat Celep, Şenel Yaran, Yakup Gülmez, Ari̇f Dolma

Turkish Journal of Electrical Engineering and Computer Sciences

The performance parameters of a total power radiometer designed as a noise measurement system for the frequency range of 12-18 GHz were investigated. The total power radiometer included a low-noise radio frequency section, a narrow-band intermediate frequency section, an average power detector, and a symmetric microwave switch. The radiometer's stability versus time was 0.343 \times 10^{-5} mW/h and its stability against temperature fluctuation was 0.0035 mW/K. The temperature fluctuation of the radiometer was less than 4 mK. We proved that there was no need for active temperature control to obtain stable radiometer gain.


Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş Jan 2012

Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş

Turkish Journal of Electrical Engineering and Computer Sciences

Depending on the evolutions in electronics, wireless sensor networks (WSNs) have been very popular in many areas of human life such as health, industry, and military. This popularity has drawn the attention of many researchers toward WSNs. WSNs are especially favorable in conditions in which it is physically difficult and dangerous for human beings to gather information. Therefore, the lifetime of those networks must be as long as possible, since it would also be infeasible to replace the energy-depleted sensors with new ones, as they may be deployed in such geographical areas that are difficult and dangerous for human beings …


A Novel Structure To Enhance Magnetic Force And Velocity In Tubular Linear Reluctance Motor, Ali Mosallanejad, Abbas Shoulaie Jan 2012

A Novel Structure To Enhance Magnetic Force And Velocity In Tubular Linear Reluctance Motor, Ali Mosallanejad, Abbas Shoulaie

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel design for a tubular linear reluctance motor (TLRM) has been developed. This paper presents a novel structure to enhance magnetic force and velocity in a TLRM. The new structure is accomplished through some changes in a TLRM, which results in a step winding structure. Comparing the proposed motor and the typical motor performances, it is proven that the proposed motor has better performance. For dynamic modeling of the proposed TLRM and to obtain the motor output characteristics, the method used for inductance profile calculation is described. The performance improvements in the proposed motor are evaluated …


Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya Jan 2012

Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the implementation of broken rotor bar fault detection in an inverter-fed induction motor using motor current signal analysis (MCSA) and prognosis with fuzzy logic. Recently, inverter-fed induction motors have become very popular because of their adjustable speed drive. They have been used in many vital control applications such as rolling mills, variable speed compressors, pumps, and fans. The condition monitoring of these motors can significantly reduce the cost of maintenance in the early detection of faults. In this study, MCSA is applied to an inverter-fed induction motor to detect broken rotor bar faults. The diagnosis of a …


Abstract Feature Extraction For Text Classification, Göksel Bi̇ri̇ci̇k, Banu Di̇ri̇, Ahmet Coşkun Sönmez Jan 2012

Abstract Feature Extraction For Text Classification, Göksel Bi̇ri̇ci̇k, Banu Di̇ri̇, Ahmet Coşkun Sönmez

Turkish Journal of Electrical Engineering and Computer Sciences

Feature selection and extraction are frequently used solutions to overcome the curse of dimensionality in text classification problems. We introduce an extraction method that summarizes the features of the document samples, where the new features aggregate information about how much evidence there is in a document, for each class. We project the high dimensional features of documents onto a new feature space having dimensions equal to the number of classes in order to form the abstract features. We test our method on 7 different text classification algorithms, with different classifier design approaches. We examine performances of the classifiers applied on …


Identification Of Linear Dynamic Systems Using The Artificial Bee Colony Algorithm, Özden Erçi̇n, Ramazan Çoban Jan 2012

Identification Of Linear Dynamic Systems Using The Artificial Bee Colony Algorithm, Özden Erçi̇n, Ramazan Çoban

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an investigation into the development of system identification using the artificial bee colony (ABC) algorithm. A system identification task can be formulated as an optimization problem where the objective is to obtain a model and a set of parameters that minimize the prediction error between the measured plant outputs and the model outputs. The most common existing system identification approaches, such as the recursive least squares method and autoregressive exogenous method, are substantially analytical and based on a mathematical derivation of the system's model. Evolutionary computation, which seems to be a very promising approach, is an alternative …


Pi And Pid Stabilization Of Neutral And Retarded Systems With Time Delay, Serdar Ethem Hamamci Jan 2012

Pi And Pid Stabilization Of Neutral And Retarded Systems With Time Delay, Serdar Ethem Hamamci

Turkish Journal of Electrical Engineering and Computer Sciences

Stabilization using fixed-order controllers is one of the key topics in control system design for the linear time-invariant (LTI) systems. In this paper, the stabilization of LTI neutral and retarded time-delay systems by means of PI and PID controllers is investigated in detail. The basic theme of the presented approach is to obtain a global stability region in the 2-dimensional (2-D) (k_p, k_i)-plane for the PI controller and in the 3-dimensional (3-D) (k_p, k_i, k_d)-space for the PID controllers. This region is formed by stability boundaries that are defined as the real root boundary, infinite root boundary, and complex root …


Adaptive Optimization Of Edca Parameters For Improved Qos In Multi-Media Applications, Alparslan Çi̇l, Mehmet Akar, Emi̇n Anarim Jan 2012

Adaptive Optimization Of Edca Parameters For Improved Qos In Multi-Media Applications, Alparslan Çi̇l, Mehmet Akar, Emi̇n Anarim

Turkish Journal of Electrical Engineering and Computer Sciences

IEEE 802.11e Enhanced Distributed Channel Access (EDCA) has been incorporated into the standard as an effective medium access mechanism in order to provide the desired QoS for multimedia applications such as VoIP and IPTV. This paper presents an adaptive optimization algorithm in EDCA which strives to provide improved QoS from both delay and throughput perspectives. As a first step towards this goal, a Markov model of the EDCA mechanism has been introduced, which is subsequently used to compute the estimates of throughput and delay. Based on the analytical model that is validated via real-time simulations in OPNET, a new algorithm …


Hybrid Mpi+Upc Parallel Programming Paradigm On An Smp Cluster, Zeki̇ Bozkuş Jan 2012

Hybrid Mpi+Upc Parallel Programming Paradigm On An Smp Cluster, Zeki̇ Bozkuş

Turkish Journal of Electrical Engineering and Computer Sciences

The symmetric multiprocessing (SMP) cluster system, which consists of shared memory nodes with several multicore central processing units connected to a high-speed network to form a distributed memory system, is the most widely available hardware architecture for the high-performance computing community. Today, the Message Passing Interface (MPI) is the most widely used parallel programming paradigm for SMP clusters, in which the MPI provides programming both for an SMP node and among nodes simultaneously. However, Unified Parallel C (UPC) is an emerging alternative that supports the partitioned global address space model that can be again employed within and across the nodes …


Low-Complexity Channel Estimation For Ofdm Systems In High-Mobility Fading Channels, Mahmut Yalçin, Aydin Akan, Hakan Doğan Jan 2012

Low-Complexity Channel Estimation For Ofdm Systems In High-Mobility Fading Channels, Mahmut Yalçin, Aydin Akan, Hakan Doğan

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, multicarrier transmission is very popular because of the high data rate requirement of wireless systems. Orthogonal frequency-division multiplexing (OFDM) is a special case of multicarrier transmission. It is considered an effective technique for frequency-selective channels because of its spectral efficiency, its robustness in different multipath propagation environments, and its ability of combating intersymbol interference. Losing subchannel orthogonality causes interchannel interference, but many conventional channel estimators assume that the channel is time-invariant during one OFDM symbol. This assumption causes error floors along the OFDM symbol for high-mobility cases. In this paper, we propose 2-dimensional pilot symbol-assisted channel estimation for wireless …


An Improved Distributed Power-Control Scheme For Cellular Mobile Systems, Hamid Farrokhi, Mostafa Rezayi Jan 2012

An Improved Distributed Power-Control Scheme For Cellular Mobile Systems, Hamid Farrokhi, Mostafa Rezayi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new distributed power-control (DPC) scheme is suggested to improve convergence speed and system robustness against carrier-to-interference-ratio (CIR) estimation errors. To expedite the CIR balancing in our DPC scheme, an instability detection rule was used. As compared with Foschini's DPC (FDPC) method, numerical results indicated that the proposed algorithm achieves performance improvements in terms of outage probability as well as in the algorithm's convergence speed. More specifically, by appropriate selection of some parameters, the algorithm speed reduces from about 90 iterations in FDPC to 9 iterations in the proposed algorithm. The system robustness against CIR estimation errors …


Training Data Optimization For Anns Using Genetic Algorithms To Enhance Mppt Efficiency Of A Stand-Alone Pv System, Ahmet Afşi̇n Kulaksiz, Ramazan Akkaya Jan 2012

Training Data Optimization For Anns Using Genetic Algorithms To Enhance Mppt Efficiency Of A Stand-Alone Pv System, Ahmet Afşi̇n Kulaksiz, Ramazan Akkaya

Turkish Journal of Electrical Engineering and Computer Sciences

Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power points are acquired by designing ANN models for PV modules. However, the parameters of PV modules are not always provided by the manufacturer and cannot be obtained readily by the user. Experimental measurements implemented in the overall PV system may be used to obtain the ANN dataset. One drawback of this method is that the generalization ability of the neural network usually degrades and some data reducing …


Adaptive Qos Scheduling In A Service-Oriented Grid Environment, Tan Fong Ang, Teck Chaw Ling, Keat Keong Phang Jan 2012

Adaptive Qos Scheduling In A Service-Oriented Grid Environment, Tan Fong Ang, Teck Chaw Ling, Keat Keong Phang

Turkish Journal of Electrical Engineering and Computer Sciences

The use of grid technology and web services for resource sharing has received tremendous attention in recent years. The merging of these 2 technologies is able to provide additional multiple types of services and functionalities. However, the problem of scheduling services to meet quality of service (QoS) requirements remains challenging. This paper proposes an adaptive QoS (AQoS) scheduling algorithm for service-oriented grid environments. AQoS uses benchmarking and curve-fitting based on historical records to estimate job length. Job length and users' QoS requirements are then used to make scheduling decisions. AQoS is able to maximize service availability, reliability, and resource utilization …


Study And Control Of 5-Level Pwm Rectifier-5-Level Npc Active Power Filter Cascade Using Feedback Control And Redundant Vectors, Thameur Abdelkrim, El Madjid Berkouk, Karima Benamrane, Tarak Benslimane Jan 2012

Study And Control Of 5-Level Pwm Rectifier-5-Level Npc Active Power Filter Cascade Using Feedback Control And Redundant Vectors, Thameur Abdelkrim, El Madjid Berkouk, Karima Benamrane, Tarak Benslimane

Turkish Journal of Electrical Engineering and Computer Sciences

The purpose of this paper is to develop a control and regulation method for the input DC voltages of a 5-level neutral point clamping (NPC) active power filter (APF). This APF is applied for the enhancement of medium-voltage network power quality by compensation of harmonic currents produced by an induction motor speed variator. In the first part, the authors present a topology of a 5-level NPC voltage source inverter and its simplified space vector pulse width modulation (SVPWM) control strategy. In the second part, the control strategy of the 5-level pulse width modulation current rectifier is presented. In the third …


Noncausal Forward/Backward Two-Pass Iir Digital Filters In Real Time, Adnane Mouffak, Belbachir Mohamed Faouzi Jan 2012

Noncausal Forward/Backward Two-Pass Iir Digital Filters In Real Time, Adnane Mouffak, Belbachir Mohamed Faouzi

Turkish Journal of Electrical Engineering and Computer Sciences

A novel method for implementing noncausal forward/backward 2-pass recursive digital filters in real time is presented. It is based on a segment-wise block processing scheme without overlapping. Factors that degrade the linearity of the overall system's transfer function are discussed. An analytical condition that corrects the system's linearity is elaborated upon using the state variable approach. A recursive algorithm is developed to compute an implementable condition for real-time filtering. A single first in, first out queue memory is introduced to ensure an organized and continuous data stream into the proposed system. This technique allows real-time, sample-by-sample filtering, and it yields …


Context Gathering And Management For Centralized Context-Aware Handover In Heterogeneous Mobile Networks, Behrouz Shahgholi Ghahfarokhi, Naser Movahhedinia Jan 2012

Context Gathering And Management For Centralized Context-Aware Handover In Heterogeneous Mobile Networks, Behrouz Shahgholi Ghahfarokhi, Naser Movahhedinia

Turkish Journal of Electrical Engineering and Computer Sciences

Context-aware handover decision has recently been considered as a candidate for next-generation heterogeneous wireless networks. The context-aware handover methods proposed in the literature differ in some aspects, including the location of the handover decision (distributed or centralized). Depending on the location of the decision point, the appropriate part of the context knowledge should be transferred in those methods. This paper proposes a context gathering mechanism for a policy-based context-aware handover method, which implements mobile-initiated and network assisted handover. The proposed network context gathering mechanism is based on a media-independent handover (MIH) framework and the paper justifies the usability of the …


Reduction Of Torque Ripple In Dtc For Induction Motor Using Input-Output Feedback Linearization, Sebti Belkacem, Farid Naceri, Rachid Abdessemed Jan 2012

Reduction Of Torque Ripple In Dtc For Induction Motor Using Input-Output Feedback Linearization, Sebti Belkacem, Farid Naceri, Rachid Abdessemed

Turkish Journal of Electrical Engineering and Computer Sciences

Direct torque control (DTC) is known to produce fast responses and robust control in AC adjustable-speed drives. However, in the steady-state operation, notable torque, flux, and current pulsations occur. In this paper, nonlinear DTC of induction motor drives is presented based on a space vector pulse-width modulation scheme combined with the input-output feedback linearization technique. The variation of stator and rotor resistance due to changes in temperature or frequency deteriorates the performance of the DTC controller by introducing errors in the estimated flux linkage and the electromagnetic torque. This approach will not be suitable for high power drives such as …


Hybrid Feature Selection For Text Classification, Serkan Günal Jan 2012

Hybrid Feature Selection For Text Classification, Serkan Günal

Turkish Journal of Electrical Engineering and Computer Sciences

Feature selection is vital in the field of pattern classification due to accuracy and processing time considerations. The selection of proper features is of greater importance when the initial feature set is considerably large. Text classification is a typical example of this situation, where the size of the initial feature set may reach to hundreds or even thousands. There are numerous research studies in the literature offering different feature selection strategies for text classification, mostly focused on filters. In spite of the extensive number of these studies, there is no significant work investigating the efficacy of a combination of features, …


Simulated Annealing Algorithm-Based Elman Network For Dynamic System Identification, Adem Kalinli Jan 2012

Simulated Annealing Algorithm-Based Elman Network For Dynamic System Identification, Adem Kalinli

Turkish Journal of Electrical Engineering and Computer Sciences

One of the well-known recurrent neural networks is the Elman network. Recently, it has been used in applications of system identification. The network has feedforward and feedback connections. It can be trained essentially as a feedforward network by means of the basic backpropagation algorithm, but its feedback connections have to be kept constant. For training success, it is important to select the correct values for the feedback connections. However, finding these values manually can be a lengthy trial-and-error process. This paper investigates the use of the simulated annealing (SA) algorithm to obtain the weight values of both the feedforward and …


Investigating The Relation Between Optimum Guard Interval And Channel Delay Spread For A Mc-Cdma System, Çeti̇n Kurnaz, Hülya Gökalp Jan 2012

Investigating The Relation Between Optimum Guard Interval And Channel Delay Spread For A Mc-Cdma System, Çeti̇n Kurnaz, Hülya Gökalp

Turkish Journal of Electrical Engineering and Computer Sciences

This paper demonstrates a novel approach to determining the optimum guard interval for a multicarrier code division multiple access (MC-CDMA) system. Analytical expressions for useful and interference power are derived as a basis for comparison. From these, an expression for the signal-to-noise ratio of a detected bit is derived and used to determine the optimum guard interval for a given channel profile and system parameters. In contrast to other works, we use channel models based on actual measurements and we highlight important differences from theoretical models to support our approach. From our results, we propose an empirical rule for optimum …


An Implementation Of Modified Scatter Search Algorithm To Transmission Expansion Planning, Majid Zeinaddini Maymand, Masoud Rashidinejad, Hamid Khorasani, Mohsen Rahmani, Amin Mahmoudabadi Jan 2012

An Implementation Of Modified Scatter Search Algorithm To Transmission Expansion Planning, Majid Zeinaddini Maymand, Masoud Rashidinejad, Hamid Khorasani, Mohsen Rahmani, Amin Mahmoudabadi

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission network expansion planning (TNEP) is one of the most important tasks in the field of power systems, especially in deregulated power system environments. TNEP is a nonlinear mixed integer programming problem that can be solved via hybrid heuristic algorithms. This paper presents a modified scatter search algorithm (MSSA) to reinforce the ordinary scatter search algorithm (SSA) to be equipped for handling large scale transmission expansion planning (TEP) problems. The proposed methodology is based on the SSA, incorporating some improved strategies so as to decrease the number of linear programming problems required to be solved iteratively. In this study, it …


Energy Savings In Simultaneous Multi-Threaded Processors Through Dynamic Resizing Of Datapath Resources, Gürhan Küçük, Mi̇ne Mesta Jan 2012

Energy Savings In Simultaneous Multi-Threaded Processors Through Dynamic Resizing Of Datapath Resources, Gürhan Küçük, Mi̇ne Mesta

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, all the designers of systems from high-performance servers to battery-operated handheld devices aim for reliability, high-performance and longevity. Central within these aims the issue of processor power consumption is becoming increasingly important. In this study, we aim to adapt our already-proven method for single-threaded superscalar processors to simultaneous multi-threaded (SMT) processors for energy savings. The original method focused on resizing datapath resources according to the demands of running applications. To achieve this, the targeted resources are physically divided into multiple partitions, and turned on and off according to the needs of the applications. Since, the energy consumption of the …


Load Sharing Based On Moving Roles In Multiagent Systems, Şebnem Bora, Ali̇ Murat Ti̇ryaki̇, Oğuz Di̇kenelli̇ Jan 2012

Load Sharing Based On Moving Roles In Multiagent Systems, Şebnem Bora, Ali̇ Murat Ti̇ryaki̇, Oğuz Di̇kenelli̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a load-sharing approach based on the refactoring of agents. According to our approach, the role(s) that makes an agent overloaded is identified and transferred to less loaded agents. The excess workload of this heavily loaded agent is then transferred to the new agent. This approach defines a new agent, called the ``monitor agent,'' which monitors the workload of agents in the organization and decides about the refactoring of the agents. The monitor agent uses the platform ontology, which explicitly describes the components of the agent organization, including agents and their roles, plans, and workloads. This …