Showing papers in "World Academy of Science, Engineering and Technology, International Journal of Electrical, Computer, Energetic, Electronic and Communication Engineering in 2007"

A PSO-Based Optimum Design of PID Controller for a Linear Brushless DC Motor

Abstract: This Paper presents a particle swarm optimization (PSO) method for determining the optimal proportional-integral- derivative (PID) controller parameters, for speed control of a linear brushless DC motor. The proposed approach has superior features, including easy implementation, stable convergence characteristic and good computational efficiency. The brushless DC motor is modelled in Simulink and the PSO algorithm is implemented in MATLAB. Comparing with Genetic Algorithm (GA) and Linear quadratic regulator (LQR) method, the proposed method was more efficient in improving the step response characteristics such as, reducing the steady-states error; rise time, settling time and maximum overshoot in speed control of a linear brushless DC motor.

Grey Prediction Based Handoff Algorithm

Abstract: As the demand for higher capacity in a cellular environment increases, the cell size decreases. This fact makes the role of suitable handoff algorithms to reduce both number of handoffs and handoff delay more important. In this paper we show that applying the grey prediction technique for handoff leads to considerable decrease in handoff delay with using a small number of handoffs, compared with traditional hystersis based handoff algorithms. Keywords— Cellular network, Grey prediction, Handoff.

Load Modeling for Power Flow and Transient Stability Computer Studies at BAKHTAR Network

Abstract: A method has been developed for preparing load models for power flow and stability. The load modeling (LOADMOD) computer software transforms data on load class mix, composition, and characteristics into the from required for commonly-used power flow and transient stability simulation programs. Typical default data have been developed for load composition and characteristics. This paper defines LOADMOD software and describes the dynamic and static load modeling techniques used in this software and results of initial testing for BAKHTAR power system.

Analysis on Modeling and Simulink of DC Motor and its Driving System Used for Wheeled Mobile Robot

Abstract: Wheeled Mobile Robots (WMRs) are built with their Wheels’ drive machine, Motors. Depend on their desire design of WMR, Technicians made used of DC Motors for motion control. In this paper, the author would like to analyze how to choose DC motor to be balance with their applications of especially for WMR. Specification of DC Motor that can be used with desire WMR is to be determined by using MATLAB Simulink model. Therefore, this paper is mainly focus on software application of MATLAB and Control Technology. As the driving system of DC motor, a Peripheral Interface Controller (PIC) based control system is designed including the assembly software technology and H-bridge control circuit. This Driving system is used to drive two DC gear motors which are used to control the motion of WMR. In this analyzing process, the author mainly focus the drive system on driving two DC gear motors that will control with Differential Drive technique to the Wheeled Mobile Robot . For the design analysis of Motor Driving System, PIC16F84A is used and five inputs of sensors detected data are tested with five ON/OFF switches. The outputs of PIC are the commands to drive two DC gear motors, inputs of Hbridge circuit .In this paper, Control techniques of PIC microcontroller and H-bridge circuit, Mechanism assignments of WMR are combined and analyzed by mainly focusing with the “Modeling and Simulink of DC Motor using MATLAB”. Keywords—Control System Design, DC Motors, Differential Drive, H-bridge control circuit, MATLAB Simulink model, Peripheral Interface Controller (PIC),Wheeled Mobile Robots.

Emerging Wireless Standards - WiFi, ZigBee and WiMAX

Abstract: The world of wireless telecommunications is rapidly evolving. Technologies under research and development promise to deliver more services to more users in less time. This paper presents the emerging technologies helping wireless systems grow from where we are today into our visions of the future. This paper will cover the applications and characteristics of emerging wireless technologies: Wireless Local Area Networks (WiFi-802.11n), Wireless Personal Area Networks (ZigBee) and Wireless Metropolitan Area Networks (WiMAX). The purpose of this paper is to explain the impending 802.11n standard and how it will enable WLANs to support emerging media-rich applications. The paper will also detail how 802.11n compares with existing WLAN standards and offer strategies for users considering higher-bandwidth alternatives. The emerging IEEE 802.15.4 (ZigBee) standard aims to provide low data rate wireless communications with high-precision ranging and localization, by employing UWB technologies for a low-power and low cost solution. WiMAX (Worldwide Interoperability for Microwave Access) is a standard for wireless data transmission covering a range similar to cellular phone towers. With high performance in both distance and throughput, WiMAX technology could be a boon to current Internet providers seeking to become the leader of next generation wireless Internet access. This paper also explores how these emerging technologies differ from one another. Keywords—MIMO technology, WiFi, WiMAX, ZigBee.

Artifacts in Spiral X-ray CT Scanners: Problems and Solutions

Abstract: Artifact is one of the most important factors in degrading the CT image quality and plays an important role in diagnostic accuracy. In this paper, some artifacts typically appear in Spiral CT are introduced. The different factors such as patient, equipment and interpolation algorithm which cause the artifacts are discussed and new developments and image processing algorithms to prevent or reduce them are presented. Keywords—CT artifacts, Spiral CT, Artifact removal.

Teager-Huang Analysis Applied to Sonar Target Recognition

Abstract: � Abstract—In this paper, a new approach for target recognition based on the Empirical mode decomposition (EMD) algorithm of Huang et al. (11) and the energy tracking operator of Teager (13)-(14) is introduced. The conjunction of these two methods is called Teager- Huang analysis. This approach is well suited for nonstationary signals analysis. The impulse response (IR) of target is first band pass filtered into subsignals (components) called Intrinsic mode functions (IMFs) with well defined Instantaneous frequency (IF) and Instantaneous amplitude (IA). Each IMF is a zero-mean AM-FM component. In second step, the energy of each IMF is tracked using the Teager energy operator (TEO). IF and IA, useful to describe the time-varying characteristics of the signal, are estimated using the Energy separation algorithm (ESA) algorithm of Maragos et al .(16)- (17). In third step, a set of features such as skewness and kurtosis are extracted from the IF, IA and IMF energy functions. The Teager- Huang analysis is tested on set of synthetic IRs of Sonar targets with different physical characteristics (density, velocity, shape,… ). PCA is first applied to features to discriminate between manufactured and natural targets. The manufactured patterns are classified into spheres and cylinders. One hundred percent of correct recognition is achieved with twenty three echoes where sixteen IRs, used for training, are free noise and seven IRs, used for testing phase, are corrupted with white Gaussian noise. Keywords—Target recognition, Empirical mode decomposition, Teager-Kaiser energy operator, Features extraction.

Direction of Arrival Estimation Based on a Single Port Smart Antenna Using MUSIC Algorithm with Periodic Signals

Abstract: In this paper we present a statistical analysis of Voice over IP (VoIP) packet streams produced by the G.711 voice coder with voice activity detection (VAD). During telephone conversation, depending whether the interlocutor speaks (ON) or remains silent (OFF), packets are produced or not by a voice coder. As index of dispersion for both ON and OFF times distribution was greater than one, we used hyperexponential distribution for approximation of streams duration. For each stage of the hyperexponential distribution, we tested goodness of our fits using graphical methods, we calculated estimation errors, and performed Kolmogorov-Smirnov test. Obtained results showed that the precise VoIP source model can be based on the five-state Markov process. Keywords—VoIP source modelling, distribution approximation, hyperexponential distribution.

Power System with PSS and FACTS Controller: Modelling, Simulation and Simultaneous Tuning Employing Genetic Algorithm

Abstract: This paper presents a systematic procedure for modelling and simulation of a power system installed with a power system stabilizer (PSS) and a flexible ac transmission system (FACTS)-based controller. For the design purpose, the model of example power system which is a single-machine infinite-bus power system installed with the proposed controllers is developed in MATLAB/SIMULINK. In the developed model synchronous generator is represented by model 1.1. which includes both the generator main field winding and the damper winding in q-axis so as to evaluate the impact of PSS and FACTS-based controller on power system stability. The model can be can be used for teaching the power system stability phenomena, and also for research works especially to develop generator controllers using advanced technologies. Further, to avoid adverse interactions, PSS and FACTS-based controller are simultaneously designed employing genetic algorithm (GA). The non-linear simulation results are presented for the example power system under various disturbance conditions to validate the effectiveness of the proposed modelling and simultaneous design approach.

Fast Extraction of Edge Histogram in DCT Domain based on MPEG7

Abstract: Due to the decoding procedure of JPEG image and filtering for edge detection, the feature extraction process of MPEG-7 Edge Histogram Descriptor (EHD) is time consuming as well as computationally expensive. To improve efficiency of compressed image retrieval, we propose a new edge histogram generation algorithm in DCT domain in this paper. Using edge information provided by the AC coefficients of DCT coefficients, we can get the direction and strength, which is utilized for the edge histogram generation, of the edge directly in DCT domain. The experimental results demonstrate that our system has good performance in terms of retrieval efficiency and effectiveness.

Implementation of TinyHash based on Hash Algorithm for Sensor Network

Abstract: In recent years, it has been proposed security architecture for sensor network.(2)(4). One of these, TinySec by Chris Kalof, Naveen Sastry, David Wagner had proposed Link layer security architecture, considering some problems of sensor network. (i.e : energy, bandwidth, computation capability,etc). The TinySec employs CBC_mode of encryption and CBC-MAC for authentication based on SkipJack Block Cipher. Currently, This TinySec is incorporated in the TinyOS for sensor network security. This paper introduces TinyHash based on general hash algorithm. TinyHash is the module in order to replace parts of authentication and integrity in the TinySec. it implies that apply hash algorithm on TinySec architecture. For compatibility about TinySec, Components in TinyHash is constructed as similar structure of TinySec. And TinyHash implements the HMAC component for authentication and the Digest component for integrity of messages. Additionally, we define the some interfaces for service associated with hash algorithm. Keywords—sensor network security, nesC, TinySec, TinyOS, Hash, HMAC, integrity

An Algorithm Proposed for FIR Filter Coefficients Representation

Abstract: Finite impulse response (FIR) filters have the advantage of linear phase, guaranteed stability, fewer finite precision errors, and efficient implementation. In contrast, they have a major disadvantage of high order need (more coefficients) than IIR counterpart with comparable performance. The high order demand imposes more hardware requirements, arithmetic operations, area usage, and power consumption when designing and fabricating the filter. Therefore, minimizing or reducing these parameters, is a major goal or target in digital filter design task. This paper presents an algorithm proposed for modifying values and the number of non-zero coefficients used to represent the FIR digital pulse shaping filter response. With this algorithm, the FIR filter frequency and phase response can be represented with a minimum number of non-zero coefficients. Therefore, reducing the arithmetic complexity needed to get the filter output. Consequently, the system characteristic i.e. power consumption, area usage, and processing time are also reduced. The proposed algorithm is more powerful when integrated with multiplierless algorithms such as distributed arithmetic (DA) in designing high order digital FIR filters. Here the DA usage eliminates the need for multipliers when implementing the multiply and accumulate unit (MAC) and the proposed algorithm will reduce the number of adders and addition operations needed through the minimization of the non-zero values coefficients to get the filter output. Keywords—Pulse shaping Filter, Distributed Arithmetic, Optimization algorithm.

Location Management in Cellular Networks

Abstract: Cellular networks provide voice and data services to the users with mobility. To deliver services to the mobile users, the cellular network is capable of tracking the locations of the users, and allowing user movement during the conversations. These capabilities are achieved by the location management. Location management in mobile communication systems is concerned with those network functions necessary to allow the users to be reached wherever they are in the network coverage area. In a cellular network, a service coverage area is divided into smaller areas of hexagonal shape, referred to as cells. The cellular concept was introduced to reuse the radio frequency. Continued expansion of cellular networks, coupled with an increasingly restricted mobile spectrum, has established the reduction of communication overhead as a highly important issue. Much of this traffic is used in determining the precise location of individual users when relaying calls, with the field of location management aiming to reduce this overhead through prediction of user location. This paper describes and compares various location management schemes in the cellular networks. Keywords—Cellular Networks, Location Area, Mobility Management, Paging.

Microarrays Denoising via Smoothing of Coefficients in Wavelet Domain

Abstract: We describe a novel method for removing noise (in wavelet domain) of unknown variance from microarrays. The method is based on a smoothing of the coefficients of the highest subbands. Specifically, we decompose the noisy microarray into wavelet subbands, apply smoothing within each highest subband, and reconstruct a microarray from the modified wavelet coefficients. This process is applied a single time, and exclusively to the first level of decomposition, i.e., in most of the cases, it is not necessary a multirresoltuion analysis. Denoising results compare favorably to the most of methods in use at the moment.

Adaptive Gait Pattern Generation of Biped Robot based on Human's Gait Pattern Analysis

Abstract: This paper proposes a method of adaptively generating a gait pattern of biped robot. The gait synthesis is based on human's gait pattern analysis. The proposed method can easily be applied to generate the natural and stable gait pattern of any biped robot. To analyze the human's gait pattern, sequential images of the human's gait on the sagittal plane are acquired from which the gait control values are extracted. The gait pattern of biped robot on the sagittal plane is adaptively generated by a genetic algorithm using the human's gait control values. However, gait trajectories of the biped robot on the sagittal plane are not enough to construct the complete gait pattern because the biped robot moves on 3-dimension space. Therefore, the gait pattern on the frontal plane, generated from Zero Moment Point (ZMP), is added to the gait one acquired on the sagittal plane. Consequently, the natural and stable walking pattern for the biped robot is obtained. Keywords—Biped robot, Gait pattern, Genetic Algorithm. I. INTRODUCTION UMANOID robots are expected to assist human activities in daily life. Therefore, humanoid robots are asked to walk natural to provide intimacy to human. The human gait is a complex dynamic activity. The complicated human model that has 3D deformable frame, high DOF, and complex mechanical structure cannot be applied directly to simplified biped robots. To overcome these problems, many researches have assumed that the human gait is optimized in the view of the gait energy, and they have defined the natural gait of the biped robot as the movement that minimizes its gait energy. Therefore, many researches about the gait pattern generation of the biped robot focus on minimizing the gait energy of them(1,2,3,4). Since a lot of the parameter values cannot be obtained only from minimizing the gait energy of the biped robot, adaptive techniques such as Genetic Algorithm and Neural Network Algorithm have been studied. Capi(5) proposed a gait synthesis method of biped robots using GA. The gait synthesis during walking is analyzed from the minimum consume energy (MCE) and minimum torque change (MTC). The stability of the robot

Pattern Classification of Back-Propagation Algorithm Using Exclusive Connecting Network

Abstract: The objective of this paper is to a design of pattern classification model based on the back-propagation (BP) algorithm for decision support system. Standard BP model has done full connection of each node in the layers from input to output layers. Therefore, it takes a lot of computing time and iteration computing for good performance and less accepted error rate when we are doing some pattern generation or training the network. However, this model is using exclusive connection in between hidden layer nodes and output nodes. The advantage of this model is less number of iteration and better performance compare with standard back-propagation model. We simulated some cases of classification data and different setting of network factors (e.g. hidden layer number and nodes, number of classification and iteration). During our simulation, we found that most of simulations cases were satisfied by BP based using exclusive connection network model compared to standard BP. We expect that this algorithm can be available to identification of user face, analysis of data, mapping data in between environment data and information.

Energy Consumption Analysis of Design Patterns

Abstract: — The importance of low power consumption is widely acknowledged due to the increasing use of portable devices, which require minimizing the consumption of energy. Energy dissipation is heavily dependent on the software used in the system. Applying design patterns in object-oriented designs is a common practice nowadays. In this paper we analyze six design patterns and explore the effect of them on energy consumption and performance. Keywords — Design Patterns, Embedded Systems, Energy Consumption, Performance Evaluation, Software Design and Development, Software Engineering.I. I NTRODUCTION HE vast majority of microprocessors being produced today are incorporated in embedded systems, which are mainly included in portable devices. The later ones require the lowest power operation achievable, since they rely on batteries for power supply. Furthermore, high power consumption raises other important issues, such as the cost associated with cooling the system, due to the heat generated. A lot of optimization efforts have been made, regarding the hardware used, to decrease power consumption [1]. However, recent research has proved that software is the dominant factor in the power consumption of a computing system [12]. Design patterns name, abstract and identify the key aspects of a common design structure that make it useful for creating a reusable object-oriented design [5]. Modern software design practice points towards the direction of design patterns, thanks to the advantages they ensue. Indeed, the software generated is reusable and flexible thus being much of a help to designers. For the aforementioned reasons, it is strongly recommended in the designers’ community that they use design patterns whenever possible. In this paper, we take a rather unconventional approach in evaluating the application of design patterns: We compare the energy being consumed in six C++ [11] code examples,

Data Acquisition from Cell Phone using Logical Approach

Abstract: — Cell phone forensics to acquire and analyze data in the cellular phone is nowadays being used in a national investigation organization and a private company In order to collect cellular phone flash memory data, we have two methods Firstly, it is a logical method which acquires files and direct ories from the file system of the cell phone flash memory Secondly, we can get all data from bit-by-bit copy of entire physical memory using a low level access method In this paper, we describe a forensic tool to acquire cell phone flash memory data using a logical level approach By our tool, we can get EFS file system and peek memory data with an arbitrary region from Korea CDMA cell phone Keywords — Forensics, logical method, acquisition, cell phone, flash memoryI I NTRODUCTION S digital evidence that kept in the various electronic media such as a computer and a mobile device in the digital crime is recently increasing, digital forensic technology to prove the crime is being more and more important Especially, if the critical evidence is stored in the mobile devices, mobile forensic technology is demanded to find out the evidence without damage of the evidence Mobile devices include small scale digital devices, embedded system, portable storage devices, and obscure devices And, as to the small scale digital devices, there are various types of cell phones, USIM, PDA, navigation system, game player, and so on In this paper, we are focusing in acquiring and analyzing data in the cell phone User data such as phonebook, call history, SMS, and photo and hardware-related data such as IMSI, MIN, and ESN are mainly stored in the NAND flash memory and the NOR flash memory of the cell phone In case of Korea, most of

Acoustic Detection of the Red Date Palm Weevil

Abstract: — In this paper, acoustic techniques are used to detect hidden insect infestations of date palm tress (Phoenix dactylifera L.). In particular, we use an acoustic instrument for early discovery of the presence of a destructive insect pest commonly known as the Red Date Palm Weevil (RDPW) and scientifically as Rhynchophorus ferrugineus (Olivier). This type of insect attacks date palm tress and causes irreversible damages at late stages. As a result, the infected trees must be destroyed. Therefore, early presence detection is a major part in controlling the spread and economic damage caused by this type of infestation. Furthermore monitoring and early detection of the disease can asses in taking appropriate measures such as isolating or treating the infected trees. The acoustic system is evaluated in terms of its ability for early discovery of hidden bests inside the tested tree. When signal acquisitions is completed for a number of date palms, a signal processing technique known as timefrequency analysis is evaluated in terms of providing an estimate that can be visually used to recognize the acoustic signature of the RDPW. The testing instrument was tested in the laboratory first then; it was used on suspected or infested tress in the field. The final results indicate that the acoustic monitoring approach along with signal processing techniques are very promising for the early detection of presence of the larva as well as the adult pest in the date palms. Keywords— Acoustic emissions, acoustic sensors, nondestructive tests, Red Date Palm Weevil, signal processing..

Non-Parametric Histogram-Based Thresholding Methods for Weld Defect Detection in Radiography

Abstract: In non destructive testing by radiography, a perfect knowledge of the weld defect shape is an essential step to appreciate the quality of the weld and make decision on its acceptability or rejection. Because of the complex nature of the considered images, and in order that the detected defect region represents the most accurately possible the real defect, the choice of thresholding methods must be done judiciously. In this paper, performance criteria are used to conduct a comparative study of four non parametric histogram thresholding methods for automatic extraction of weld defect in radiographic images. Keywords—Radiographic images, non parametric methods, histogram thresholding, performance criteria.

A New Version of Unscented Kalman Filter

Abstract: — This paper presents a new algorithm which yields a nonlinear state estimator called iterated unscented Kalman filter. This state estimator makes use of both statistical and analytical linearization techniques in different parts of the filtering process. It outperforms the other three nonlinear state estimators: unscented Kalman filter (UKF), extended Kalman filter (EKF) and iterated extended Kalman filter (IEKF) when there is severe nonlinearity in system equation and less nonlinearity in measurement equation. The algorithm performance has been verified by illustrating some simulation results. Keywords — Extended Kalman Filter, Iterated EKF, Nonlinear state estimator, Unscented Kalman Filter.I. I NTRODUCTION CCURATE estimation of state variables of systems is important for fault detection and control applications. However, estimation in nonlinear systems is not easy to deal with. The optimal (Bayesian) solution to the problem requires propagation of description of full probability density function (pdf) [1]. This solution is general and includes factors such as multimodality, asymmetries, and discontinuities. However, since the form of pdf is not restricted, it cannot, in general, be represented using finite number of parameters. Therefore, any practical estimator must use an approximation of some kinds. Many different types of approximations have been developed; unfortunately, most are either computationally unmanageable or require special assumptions about the form of the process and observation models that cannot be satisfied in practice. For these and other reasons, the KF remains the most widely used estimation algorithm. The most common application of the KF to nonlinear systems is in the form of extended KF (EKF) [2, 3]. EKF was first used by Wu et al. to find the 3D location. Exploiting the assumption that all transformations are quasi-linear, the EKF simply linearizes all nonlinear transformations and substitutes Jacobian matrices for the linear transformations in the KF equations. In addition, EKF is very convenient and fast for real-time processing and quite straightforward to implement if a priori information of the measurement and process noise covariance matrices are available. Linearization in EKF

Comparison of the DC/DC-Converters for Fuel Cell Applications

Abstract: The source voltage of high-power fuel cell shows strong load dependence at comparatively low voltage levels. In order to provide the voltage of 750V on the DC-link for feeding electrical energy into the mains via a three phase inverter a step-up converter with a large step-up ratio is required. The output voltage of this DC/DC-converter must be stabile during variations of the load current and the voltage of the fuel cell. This paper presents the methods and results of the calculation of the efficiency and the expense for the realization for the circuits of the DC/DC-converter that meet these requirements. Keywords—DC/DC-converter, calculation, efficiency, fuel cell.

Downlink Scheduling and Radio Resource Allocation in Adaptive OFDMA Wireless Communication Systems for User-Individual QoS

Abstract: In this paper, we address the problem of adaptive radio resource allocation (RRA) and packet scheduling in the downlink of a cellular OFDMA system, and propose a downlink multi-carrier proportional fair (MPF) scheduler and its joint with adaptive RRA algorithm to distribute radio resources among multiple users according to their individual QoS requirements. The allocation and scheduling objective is to maximize the total throughput, while at the same time maintaining the fairness among users. The simulation results demonstrate that the methods presented provide for user more explicit fairness relative to RRA algorithm, but the joint scheme achieves the higher sum-rate capacity with flexible parameters setting compared with MPF scheduler.

Coordinated Design of TCSC Controller and PSS Employing Particle Swarm Optimization Technique

Abstract: This paper investigates the application of Particle Swarm Optimization (PSO) technique for coordinated design of a Power System Stabilizer (PSS) and a Thyristor Controlled Series Compensator (TCSC)-based controller to enhance the power system stability. The design problem of PSS and TCSC-based controllers is formulated as a time domain based optimization problem. PSO algorithm is employed to search for optimal controller parameters. By minimizing the time-domain based objective function, in which the deviation in the oscillatory rotor speed of the generator is involved; stability performance of the system is improved. To compare the capability of PSS and TCSC-based controller, both are designed independently first and then in a coordinated manner for individual and coordinated application. The proposed controllers are tested on a weakly connected power system. The eigenvalue analysis and nonlinear simulation results are presented to show the effectiveness of the coordinated design approach over individual design. The simulation results show that the proposed controllers are effective in damping low frequency oscillations resulting from various small disturbances like change in mechanical power input and reference voltage setting. Keywords—Particle swarm optimization, Phillips-Heffron model, power system stability, PSS, TCSC.

Design of Gain Scheduled Fuzzy PID Controller

Abstract: � Abstract—An adaptive fuzzy PID controller with gain scheduling is proposed in this paper. The structure of the proposed gain scheduled fuzzy PID (GS_FPID) controller consists of both fuzzy PI-like controller and fuzzy PD-like controller. Both of fuzzy PI-like and PD-like controllers are weighted through adaptive gain scheduling, which are also determined by fuzzy logic inference. A modified genetic algorithm called accumulated genetic algorithm is designed to learn the parameters of fuzzy inference system. In order to learn the number of fuzzy rules required for the TSK model, the fuzzy rules are learned in an accumulated way. In other words, the parameters learned in the previous rules are accumulated and updated along with the parameters in the current rule. It will be shown that the proposed GS_FPID controllers learned by the accumulated GA perform well for not only the regular linear systems but also the higher order and time-delayed systems.

A Novel Multiple Valued Logic OHRNS Modulo rn Adder Circuit

Abstract: Residue Number System (RNS) is a modular representation and is proved to be an instrumental tool in many digital signal processing (DSP) applications which require high-speed computations. RNS is an integer and non weighted number system; it can support parallel, carry-free, high-speed and low power arithmetic. A very interesting correspondence exists between the concepts of Multiple Valued Logic (MVL) and Residue Number Arithmetic. If the number of levels used to represent MVL signals is chosen to be consistent with the moduli which create the finite rings in the RNS, MVL becomes a very natural representation for the RNS. There are two concerns related to the application of this Number System: reaching the most possible speed and the largest dynamic range. There is a conflict when one wants to resolve both these problem. That is augmenting the dynamic range results in reducing the speed in the same time. For achieving the most performance a method is considered named “One-Hot Residue Number System” in this implementation the propagation is only equal to one transistor delay. The problem with this method is the huge increase in the number of transistors they are increased in order 2 m . In real application this is practically impossible. In this paper combining the Multiple Valued Logic and One-Hot Residue Number System we represent a new method to resolve both of these two problems. In this paper we represent a novel design of an OHRNS-based adder circuit. This circuit is useable for Multiple Valued Logic moduli, in comparison to other RNS design; this circuit has considerably improved the number of transistors and power consumption. Keywords—Computer Arithmetic, Residue Number System, Multiple Valued Logic, One-Hot, VLSI.

Design of Robust Fuzzy Logic Power System Stabilizer

Abstract: Power system stabilizers (PSS) must be capable of providing appropriate stabilization signals over a broad range of operating conditions and disturbance. Traditional PSS rely on robust linear design method in an attempt to cover a wider range of operating condition. Expert or rule-based controllers have also been proposed. Recently fuzzy logic (FL) as a novel robust control design method has shown promising results. The emphasis in fuzzy control design center is around uncertainties in the system parameters & operating conditions. In this paper a novel Robust Fuzzy Logic Power System Stabilizer (RFLPSS) design is proposed The RFLPSS basically utilizes only one measurable ∆ω signal as input (generator shaft speed). The speed signal is discretized resulting in three inputs to the RFLPSS. There are six rules for the fuzzification and two rules for defuzzification. To provide robustness, additional signal namely, speed are used as inputs to RFLPSS enabling appropriate gain adjustments for the three RFLPSS inputs. Simulation studies show the superior performance of the RFLPSS compared with an optimally designed conventional PSS and discrete mode FLPSS. Keywords—Controller design, Fuzzy Logic, PID, Power System Stabilizer, Robust control.