per Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06125561articleS. Vaez-Zadeh - Personal pagevaezs@ut.ac.ir1A. Paymana.payman@ece.ut.ac.ir2University of TehranUniversity of TehranRecently, performance improvement and speed control of Single-Phase Induction Motors (SPIMs) have been paid attention. These aims is required the machine speed. In this paper, a method is proposed to estimate the SPIMs speed, and then, its application in torque optimization of the machine is investigated. For this purpose, the motor speed is obtained in terms of the motor parameters and stator flux linkage components by use of the SPIMs equations in stationary reference frame. By obtaining the flux linkage from motor windings voltages and currents, the motor speed is estimated desirably. Then the estimated speed is used to increase the average torque, to decrease the pulsation torque and to optimize the motor torque. After that, the simulation results in condition of using the real speed is compared with the estimated speed one. The low simulation error proves the validity of the proposed methodhttp://ijece.org/Article/27817Torque optimizationspeed estimationstationary reference framesingle phase induction motorper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06126268articleM. B. B. Sharifiasharifian@tabrizu.ac.ir1J. Faizjfaiz@ut.ac.ir2University of TehranIn this paper a squirrel-cage three-phase induction motor, selected as the driving power of an EV, is designed optimally using Modified-Hooke-Jeeves optimization technique. The optimal designs are analyzed and compared with varying pole number, rated base speed and slot shapes. This optimization technique has same advantages such as simple programming, non-gradient, short convergence time and independently variation of each parameter. Variation of design parameters of optimally designed motors versus rated base speed for 2 and 4-pole motors are presented and discussed. The results show that a 2-pole motor with parallel-sided stator and rotor slots and rated speed 1800 rpm have the best performancehttp://ijece.org/Article/27818Optimal designelectrical vehicleinduction motorper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06126975articleM. parnianiparniani@sharif.edu1R. Bagherireza_baghery@yahoo.com2To benefit form advantages of parallel operation of diesel-generators, their rapid and smooth synchronization is required. A new method in design and implementation of such a synchronizer, based on phase locked loop (PLL), is described and test results are presented. The synchronizer automatically controls the generator to achieve zero phase difference, and then issues the synchronization command. The main advantage of the method over other synchronizers is to lock on the perfect synchronous state using PLL. Thus, there is no need to consider circuit breaker operating time and to estimate proper synchronization instant. The result is faster and more reliable synchronization as compared to the existing typeshttp://ijece.org/Article/27819Synchronizerphase locked loopdiesel-generatorparallel operationper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06127680articleMohammad Farzimfarzi@jdevs.com1S. A. Abrishamifarabrishamifar@iust.ac.ir2M. Mirzargarmasmirzargar@jdevs.com3M. Fazelimfazeli@jdevs.com4University of Science and Technology-http://ijece.org/Article/27820Series connected thyristorshigh voltage switchprotectionper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06128191articleM. R. »hojastehkhojasteh@ce.aut.ac.ir1M. R. Meybodimmeybodi@aut.ac.ir2Agents are software entities that act continuously and autonomously in a special environment. It is very essential for the agents to have the ability to learn how to act in the special environment for which they are designed to act in, to show reflexes to their environment actions, to choose their way and pursue it autonomously, and to be able to adapt and learn. In multi-agent systems, many intelligent agents that can interact with each other, cooperate to achieve a set of goals. Because of the inherent complexity that exists in dynamic and changeable multi-agent environments, there is always a need to machine learning in such environments. As a model for learning, learning automata act in a stochastic environment and are able to update their action probabilities considering the inputs from their environment, so optimizing their functionality as a result. Learning automata are abstract models that can perform some numbers of actions. Each selected action is evaluated by a stochastic environment and a response is given back to the automata. Learning automata use this response to choose its next action. In this paper, the goal is to investigate and evaluate the application of learning automata to cooperation in multi-agent systems, using soccer server simulation as a test-bed. Because of the large state space of a complex multi-agent domains, it is vital to have a method for environmental states’ generalization. An appropriate selection of such a method can have a great role in determining agent states and actions. In this paper we have also introduced and designed a new technique called “The best corner in state square” for generalizing the vast number of states in the environment to a few number of states by building a virtual grid in agent’s domain environment. The efficiency of this technique in a cooperative multi-agent domain is investigatedhttp://ijece.org/Article/27821Learning automataagentmulti-agent systemssimulated robotic soccerteam of agentscooperationper Iranian Research Institute for Electrical Engineeringفصلنامه مهندسی برق و مهندسی کامپيوتر ايران16823745168237452003-06129298articleB. Alizadehbijan@cad.ece.ut.ac.ir1Z. Navabinavabi@ece.neu.edu2University of TehranUniversity of TehranThis paper describes the use of polynomial integer equations for high level model of digital circuits for property checking formal verification at this level. Most formal verification methods use low-level representations of a design like BDDs. BDD operations are not applicable to a large datapath because of large CPU time and memory usage. In our method, a behavioral state machine is represented by a list of integer equations, and RT level properties are directly applied to this representation. Furthermore, this method is applied to circuits without having to separate their data and control sections. For this implementation, we use a canonical form of integer equations, which simplifies equations instead of solving them. This paper compares our results with those of the VIS verification tool that is a BDD based programhttp://ijece.org/Article/27822Transition relation functions integer equations solverpolynomial integer equationsBDD Boolean satisfiability