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The four-leg voltage source inverter (VSI) is becoming increasingly popular in power applications due to its superior performance characteristics such as relatively low dc-bus voltage and capability to handle unbalanced or nonlinear load currents. With unbalanced load condition, to balance such a system, a neutral connection is needed to control each phase voltage independently. Average large signal...
In this paper a robust intelligent controller is adopted in order to fulfil maximum power point tracking (MPPT) algorithm for permanent magnet synchronous generator (PMSG) with the application of wind turbines. Conventional linear PI controller is simple and easy to implement but it has the drawback of dependence on system parameters especially in a wind energy conversion system with large amount...
Simple structure, quick, and robust response of direct torque control (DTC) make it attractive in ac drives. However, in sensorless applications, precise estimation of rotor speed is a crucial issue as well as the torque and flux estimation. In this paper an adaptive flux observer is introduced with stator current and flux vector components as state variables and rotor speed as an unknown parameter...
This paper presents an optimum switching pattern for the space vector modulation (SVM) of matrix converters based on a genetic algorithm. The possibility of choosing the sequence of active duty cycles, and the ability to allocate the duration of the inactive duty cycle to each one of the zero duty cycles in a matrix converter SVM, provide some degrees of freedom in designing of the switching pattern...
One of the features of the Next Generation Wireless Networks (NGWNs) is its heterogeneous communication environment. Heterogeneous networks are ranging from wireless WAN, LAN, MAN and PAN. The most important parameters in this regard are different data rates and coverage of these networks. In this paper, we propose an evolvable fuzzy logic-based algorithm for managing handover process in heterogeneous...
In this paper, membership function shapes and types and the fuzzy rules of fuzzy systems are adjusted by using a Intelligent Gravitational Search Algorithm (IGSA) in order to obtain an optimal fuzzy system. The advantages of this method in classifying various data sets are illustrated. Possible extensions of this technique are briefly discussed.
Flexible job shop scheduling problem (FJSP) is an important extension of the classical job shop scheduling problem, where each operation could be processed on more than one machine and vice versa. Since it has been proven that this problem is strongly NP-hard, it is difficult to achieve an optimal solution with traditional optimization algorithms. In this paper a new approach is proposed to solve...
Reinforcement Learning is a popular context of machine learning that aims at improving the behavior of autonomous agents that learn from interactions with the environment. However, it is often costly, time consuming, and even dangerous. To deal with these problems, reward shaping has been used as a powerful method to accelerate the learning speed of the agent. The principle idea is to incorporate...
In this paper, the issue of autonomous parallel parking of a vehicle in a limited space has been considered based on a parked vehicle in front. A Radial Basis Function Network (RBFN) has been developed to online path generation according to the measured distance from the parked vehicle. These measurements are obtained by employing two sonar sensors mounted in the front left corner of the vehicle....
A new stable Adaptive Interval Type-2 Fuzzy Proportional Integral Sliding Mode Controller (AI2FPISMC) is introduced here to control a class of nonlinear systems. The proposed method is based on interval type-2 fuzzy logic system (IT2FLS) whose antecedent and consequent membership functions are interval type-2 fuzzy sets. IT2FLS is utilized to approximate unknown nonlinear functions. To achieve high...
Nowadays, utilizing heuristic algorithms is highly appreciated in solving optimization problems. The fundamental of these algorithms are inspired by nature. The gravitational search algorithm (GSA) is a novel heuristic search algorithm which is invented by using law of gravity and mass interactions. In this paper, a new operator is presented which is called “the black hole”. This operator is inspired...
In recent years, with growth of online learning technology, a huge amount of e-learning resources have been generated in various media formats. This growth has caused difficulty of locating appropriate learning resources to learners. A personalized recommendation is an enabling mechanism to overcome information overload occurred in the new learning environments and deliver suitable learner resources...
In this paper a new electromagnetism-like mechanism is proposed for combinatorial optimization of capacitated vehicle routing problem. electromagnetism-like mechanism is a new metaheuristic method and inspired by the attraction and repulsion mechanism of the electromagnetism theory. we propose a new electromagnetism-like mechanism that it includes a new distance measure between solutions and new effective...
The university course timetabling problem (UCTP) is a classical, old and famous problem in the field of optimization problems. The purpose of UCTP is to schedule a number of events (courses) in proper timeslots and suitable rooms. In this problem, there are some hard and soft constraints. A feasible timetable must satisfy all hard constraints. In addition, each soft constraint violation causes a penalty...
This paper considers the design of robust observers for a class of continuous-time nonlinear systems presented by Takagi-Sugeno (T-S) model with nonlinear subsystems and unmeasurable premise variables. The proposed T-S structure reduces the number of rules in the Sugeno model by using local nonlinear rules. Moreover, it can represent larger class of nonlinear systems as compared to the measurable...
One of the noticeable topics in fuzzy logic controllers is parameter controllingof heuristic search algorithms. In this paper, one of the parameters of Gravitational Search Algorithm, GSA, is controlledusing fuzzy logic controller to achieve better optimization results and to increase convergence rate. Several experiments are performed and results are compared with the results of the original GSA...
In this paper, we introduce AUBUE — Adaptive User-Interface Based on User's Emotion in which a user's emotions are detected according to interactions of the user with keyboard; then user interface's color is adopted regarding to users' emotion. AUBUE includes four elements: keyboard interpretation, event interpretation, mood update, and color selection. In the keyboard interpretation element, interactions...
Extremal optimization (EO) algorithm is a kind of evolutionary optimization method which has been applied successfully in different fields. In this paper a new framework is proposed for applying extremal optimization in image segmentation. oversegmented images are the initial to EO which works on two levels: segments and pixels. A new energy function is defined for segments and the energy function...
Today, the churn phenomenon has been considered in many applications as an important outcome. Social networks can be considered as one of the most important applications with the mentioned outcome. Churn in social networks depends on the users' activity in a communication environment and appears if this activity is less than a required extent. Swarm Intelligence algorithms(SI), assumed to be the proper...
In this paper we address sales forecasting of brake rubber for 1600 pickup truck manufactured by Iran Khodro Co. To this end, we use two different methods named Neural Network (NN) and regression model. Further, we develop two types of neural networks, one general network and a set of monthly networks. Results reveal that when data are nonlinear and chaotic, traditional models like regression are...
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