WSEAS Transactions on Circuits and Systems

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Print ISSN: 1109-2734
E-ISSN: 2224-266X

Volume 11, 2012

Issue 1, Volume 11, January 2012

Title of the Paper: Electromagnetic Field of the Large Power Cables and Impact on the Human Health

Authors: Daniela Carstea

Abstract: In this work we survey our research on domain decomposition and related algorithms for large power electric cables and the impact on the human health. The equations that describe the behaviour of the fields in electromagnetic devices are coupled because most of the material properties are temperature dependent and may depend on temperature in a nonlinear way. More, any power loss is transformed in local heating so that the heat source in the thermal model is the Joule-Lenz effect of the electrical current. Here we assume that the sources of the magnetic field have sinusoidal time dependence and we neglect the effects due to the displacement currents. The target example is from the electric engineering. It is a large power cable in a free space. General symmetry of the device can be used for efficient software. The algorithms for analysis are presented in the context of the finite element method. The results can be extended for simulation of distributed-parameter systems described by elliptic and parabolic equations. The domain decomposition at the level of the problem is used. In this way the coupled magneto-thermal problem can be analyzed by a reduction of the computational effort.

Keywords: Electrical cables; Coupled fields; Finite element method; Bioheat equation.

Title of the Paper: Design of Logical Structures and Characteristics analysis of AOI for Quantum Dot Cellular Automata

Authors: S. Karthigai Lakshmi, G.Athisha

Abstract: Quantum dot Cellular Automata (QCA) offers a new transistorless computing paradigm in nanotechnology. It has the potential for attractive features such as faster speed , smaller size and low power consumption than transistor based technology .By taking the advantages of QCA we are able to design interesting computational architecture. The basic logic elements used in this technology are the inverter and the majority gate (MG). The majority gate is not a universal gate .Hence another important logic gate introduced in this technology is And-Or-Inverter (AOI).In this paper, we propose design of different logical structures using AOI. The rules are introduced in this paper for easy implementation of AOI circuits for different functions and characteristics of AOI is also defined and analyzed. Design implementations using the AOI gate are compared with the conventional CMOS and majority gate based QCA methodology.

Keywords: QCA, QCADesigner, MG, AOI, CMOS, Computing and Nanotechnology

Title of the Paper: Fuzzy Logic Based Smart Anaesthesia Monitoring System in the Operation Theatre

Authors: Mirza Mansoor Baig, Hamid Gholamhosseini, Michael J. Harrison

Abstract: Man has a limited ability to accurately and continuously analyse large amounts of data. In recent years, there has been a rapid growth in patient monitoring and medical data analysis using decision support systems, smart alarm monitoring, expert systems and many other computer aided protocols. The main goals of this study are to enhance the developed diagnostic alarm system for detecting critical events during anaesthesia and to accurately diagnose a hypovolaemia event in anaesthetized patients. The performance of the proposed diagnostic system, fuzzy logic monitoring system-2 (FLMS-2), was validated through a series of off-line tests. When detecting hypovolaemia a substantial level of agreement was observed between FLMS-2 and the human expert and it is shown that system has a better performance with sensitivity of 94%, specificity of 90% and predictability of 72%.

Keywords: Fuzzy logic monitoring, anaesthesia monitoring, patient monitoring system, ANFIS, FIS

Issue 2, Volume 11, February 2012

Title of the Paper: Dynamic Performance Analysis of T Network Impedance Matching

Authors: Rui-Jin Liao, Jian-Wen Tan, Hua Wang, Long Li, Sheng-Ze Qiang

Abstract: Harmonic rejection ability and reflection coefficient are the most important factors in the design of impedance matching network. However, dynamic stability of impedance matching should be taken into account in applications existing working frequency drift, load impedance variation and components deviation due to tolerances and process variation. In order to study the dynamic performance of T network impedance matching, theoretical analysis is conducted in accordance with the Q (quality)-based design method. The relationships between the matching result (reflection coefficient) and components deviation, load impedance variation and operating frequency drift are obtained. The analysis results suggest that higher Q value produces worse dynamic stability and that matching result is more sensitive to load impedance variation when the load reflection coefficient of static state is larger. In designing a T network, it is need to make the tradeoff between dynamic stability and harmonic rejection ability. The analysis results provide theoretical basis for the design and characteristics analysis of T network impedance matching.

Keywords: Impedance Matching, Circuit Analysis, Dynamic Performance, Component Tolerance, Frequency Drift, Circuit Design

Title of the Paper: A Hardware Architecture for Motion Compensated Video Frame Rate Up-Conversion

Authors: Huong Ho

Abstract: A hardware architecture for motion compensated, video frame rate up-conversion (MC-FRUC) applications is presented in this paper. The MC-FRUC architecture has been designed based on an advanced motion estimation (ME) and motion compensated frame interpolation (MCFI) algorithm to achieve interpolated frames with high level of quality. The proposed architecture is a flexible and highly parallel MC-FRUC that has been designed to support frame rate-up conversion (FRUC) for high definition (HD) video at high frame rate. The ME building block of the MC-FRUC circuit is a reconfigurable structure designed to support reconfigurations for single or multiple reference frames. The MCFI building block performs frame interpolation with the objective of minimizing of block artifacts, overlapping, and holes for the interpolated frames. Hardware implementations for the MC-FRUC design were carried out on FPGA where the circuit high performance FRUC capability has been validated.

Keywords: Frame rate up-conversion, Multi-frame motion estimation, Motion-compensated frame interpolation, Hardware architecture, FPGA implementation, Reconfigurable

Title of the Paper: Fuzzy Internal Model Control of Nonlinear Plants with Time Delay based on Parallel Distributed Compensation

Authors: Snejana Yordanova, Tasho Tashev

Abstract: The parallel-distributed compensation (PDC) together with Takagi-Sugeno-Kang (TSK) fuzzy modelling proved to be a modern model-based systematic approach for the design of fuzzy nonlinear controllers from stability and robustness requirements. The usual local linear controllers comprise a state feedback. This requires measurements of the state variables or an observer design. The aim of the present investigation is to develop a fuzzy internal model controller (FIMC) for a nonlinear plant with time delay under uncertainties. The FIMC is PDC-TSK based with dynamic local linear controllers, which are designed on the principle of the internal model controllers to ensure local linear systems stability and robustness. The main contribution of the paper is a method for the design of a FIMC, designed FIMC for the control of the air temperature in a laboratory furnace and MATLAB based simulation investigations of the closed loop system stability and dynamic performance. The FIMC reduces the settling time and the overshoot and improves the system robustness compared to a linear PI controller.

Keywords: Fuzzy internal model control, MATLAB, robustness, simulation, stability, temperature, time delay

Issue 3, Volume 11, March 2012

Title of the Paper: A Novel Complete High Precision Standard Linear Element-Based Equivalent Circuit Model of CMOS Gyrator-C Active Transformer

Authors: Rawid Banchuin

Abstract: In this research, the novel equivalent circuit model of the CMOS gyrator-C active transformer has been proposed. Besides the effect of the unwanted intrinsic elements, the effect of the finite open loop bandwidth, which was neglected in previous research, is also taken into account. By this reason, it is a complete model. The proposed model is constructed based upon the simple standard linear elements and can accurately simulate the characteristics of the CMOS gyrator-C active transformer for various decades of frequency which cover the operating range of the on-chip monolithic transformer given by a few GHz up to 10 GHz. The percentage of deviations between each of the parameters obtained from the equivalent circuit model and a similar one obtained from the original active transformer were found to be very small, for example, the deviation between the Re[z11], Im[z11] and Re[z21] of the model and the topology II active transformer have been found to be lower than 0.007%, 0.2703% and 0.0139% respectively. The average computational times for the simulations are significantly reduced by using this model. Hence, the proposed model has been found to be a convenient tool for both manual and computer based analysis/design of various applications involving the CMOS gyrator-C active transformer. Furthermore, a simple procedure to minimize the effects of both major nonidealities is also discussed.

Keywords: On-chip monolithic transformer, CMOS gyrator-C active transformer, Equivalent circuit model, Standard linear element, High order element

Title of the Paper: FPGA Implementation of Elliptic Curve Cryptography Engine for Personal Communication Systems

Authors: M. B. I. Reaz, J. Jalil, H. Husian, F. H. Hashim

Abstract: Elliptic Curve Cryptography (ECC), which allows smaller key length as compared to conventional public key cryptosystems, has become a very attractive choice in wireless mobile communication technology and personal communication systems. In this research, the ECC encryption engine has been implemented in Field Programmable Gate Arrays (FPGA) for two different key sizes, which are 131 bits and 163 bits. The cryptosystem, which has been implemented on Altera’s EPF10K200SBC600-1, has taken 5945 and 6913 logic cells out of 9984 for the key sizes of 131 bits and 163 bits respectively with an operating frequency 43 MHz, and performs point multiplication operation in 11.3 ms and 14.9 ms for 131 bits and 163 bits implementation respectively. In terms of speed, the cryptosystem implemented on FPGA is 8 times faster than the software implementation of the same system.

Keywords: Encryption, ECC, FPGA, Synthesis, Hardware

Title of the Paper: A New Fuzzy Positive and Negative Ideal Solution for Fuzzy TOPSIS

Authors: Mehdi Amiri-Aref, Nikbakhsh Javadian, Mohammad Kazemi

Abstract: This paper presents a fuzzy multiple criteria decision making (FMCDM) problem with the Technique for Order Performance by Similarity to Ideal Solution (TOPSIS) based on the new concept of positive and negative ideal solution. Whereas decision making is a process which accuracy of data play major role to select the best alternative, considering decision making problems in fuzzy environments motivate the authors to search in this field. Triangular fuzzy numbers (TFN) among decision making process are used to evaluate the weighted different alternatives versus various criteria and a fuzzy group weight is made by different experts. In this paper, additionally, a new fuzzy distance formula is applied to compute distance between each alternative and positive as well as negative ideal solution. There is a flexibility to consider general fuzzy numbers (such as triangular, trapezoidal, interval), though. Then, new fuzzy TOPSIS to determine the ranking order of the alternatives is also presented. Finally, a numerical example from the literature is solved to demonstrate applicability of the proposed model. The comparison of illustrated algorithm with the three methods in the literature on various examples proved the efficiency of our decisions.

Keywords: TOPSIS, Fuzzy Numbers, Fuzzy Distance, Positive Ideal Solution, Negative Ideal Solution

Issue 4, Volume 11, April 2012

Title of the Paper: Impact on the Fuzzy Modeling in Operation of Electric Distribution Systems

Authors: Gheorghe Grigoras, Gheorghe Cartina

Abstract: Estimation of the load, particularly of the peak load, is basis for the system state estimation, and for technical, and economic calculations. This makes possible improvement in economic operation, maintenance of electrical equipment, and optimal planning and operating of electrical distribution systems. In the paper, starting from a fuzzy correlation model of the loads, a power flow analysis from an electric distribution system with the 20 kV voltage level is presented. The results showed that using a fuzzy correlation model for the loads from the 20 kV nodes puts a new quality into the electric distribution system analysis in uncertain conditions.

Keywords: fuzzy model, correlation loads, peak load, electric distribution system, power flow analysis

Title of the Paper: Self-Algorithm Traffic Light Controllers for Heavily Congested Urban Route

Authors: S. K. Subramaniam, M. Esro, F. L. Aw

Abstract: Traffic lights are commonly known as the stop light or stop-and-go lights used as a source of signaling device in junctions around the world. It is common to position traffic lights on a certain road intersections, pedestrian crossings and other locations to control competing flows of traffic in order to enhance the smoothness of traffic flow. Traffic lights have been installed in most cities around the world regardless of different standards set by the local authorities. Traffic light controllers is programmed to assign timely directions for road users by demand in the form of colors which is Red, Amber and Green. Even though traffic lights are known as the best device in controlling traffic flow for road users, yet accidents reported at the traffic junction is very common. There are 2 methods in controlling the traffic light system placed on a certain junction. The most common one is the sequencing method, whereby the traffic light system is designed to operate according to the preprogrammed sequence without any consideration of real time behavior. The second method is the demand based controller which response to the preprogrammed timer based on real time sensor detection on a certain road junction. With both method widely used around the world, surety on traffic flow smoothness is not established. When authorities talk about efficiency and accuracy on real time traffic flow control, there are always room for further enhancement especially on the controlling and sensing method. In the afford to provide a solution for such miseries, a novel implementation of sensing method which will be incorporated with self conditioning program will be a practical solution. The new sensing method is capable of counting the total number of vehicles entering a certain junction and exiting from a certain junction on real time basis. Based on this detection, the programmable logic controller will trigger the traffic light indicators according to real demand. The new method should also be easy for further enchantment of traffic light system in ensuring smoothness of traffic flow especially during peak hours.

Keywords: Traffic Light System, self-algorithm traffic light, multiple junction traffic light, metal detector, programmable logic controller

Title of the Paper: New Model for the Search for Comfort Through Surveys

Authors: Pablo Aparicio Ruiz, José Guadix Martín, Jesús Muñuzuri Sanz, Luis Onieva Giménez

Abstract: This paper presents a methodology used to provide important and useful information to select dynamically the comfort set-point of the rooms for a central heating system without using fixed values based on programmed time schedules or any other methodology. It is possible to observe the users comfort level of a Heating, Ventilation and Air-conditioning (HVAC) system through online surveys. Using fuzzy logic applied to the behaviour patterns that generally occur in an office it is possible to detect situations when it can be decided to maximise comfort and/or maximise savings. This methodology is designed to save energy in these systems depending on the occupation and comfort perception of its occupants.

Keywords: Comfort, fuzzy logic, decision support system, online surveys, evaluation, HVAC

Issue 5, Volume 11, May 2012

Title of the Paper: Performance Analysis of a Multi-Source, Single-Output, Buck-Boost DC-AC Converter Feeding Active Power to a 3-Phase Distribution Grid

Authors: M. Ezzat

Abstract: No doubt that, power electronics play an important role in the modern industry and power system networks. This paper presents the performance analysis of a multi-source, single-output, buck-boost dc-ac converter suitable for use in different applications such as feeding ac loads from photovoltaic systems. In this paper, the performance of the proposed converter is studied, through power simulation program (PSIM), under different modes of operation during feeding active power to a distribution network. The most important features of the proposed converter are the possibility to control voltage, frequency, voltage and frequency together, and the low value of the total harmonic distortion (THD) in the voltage and current waveforms.

Keywords: Buck-Boost, DC-AC Converter, Design, Performance, Simulation

Title of the Paper: Effective Optimization of the Control System for the Cement Raw Meal Mixing Process: Simulating the Effect of the Process Parameters on the Product Homogeneity

Authors: Dimitris Tsamatsoulis

Abstract: The main factors that influence the quality of the raw meal during its production in a ball mill and storage in stock and homogenisation silos of continuous flow are investigated. A detailed simulation is used, incorporating all the key characteristics of the processes. The quality modules of the raw meal are controlled via robust PID controllers, optimized with the same simulator. The effect of the qualitative consistency of the raw materials, of the active volume of the material contained in the silos, of the stock silo filling degree, of the sampling period and of the time needed for preparation and analysis is quantified. The developed simulator, not only can be applied to obtain the optimum PID parameters among the sets satisfying certain robustness criteria, but also to determine optimum conditions of the process parameters.

Keywords: Dynamics, Raw meal, Quality, Mill, Model, Variance, PID, Robustness, Homogeneity

Title of the Paper: STATCOM Control Strategy Based on Lyapunov Energy Function and Fuzzy Logic Control for Improving Transient Stability of Multimachine Power System

Authors: Prechanon Kumkratug

Abstract: This paper proposes a nonlinear control strategy of a Static Synchronous Compensator (STATCOM) for improving transient stability of multimachine power system. The large scale and the complexity of modern power system require the nonlinear control strategy of the STATCOM. The concept of Lyapunov energy function is applied to derive the nonlinear control strategy and the proposed control based on Lyapunov energy function is locally measurable signal. The fuzzy logic control is also applied to overcome the uncertainties of various disturbances in the multimachine power system. This paper presents the method of investigating the transient stability of the multimachine power system equipped with the STATCOM. The proposed control strategy and the method of simulation are tested on the Kundur’s inter-area power system and new England power system. It is found that the proposed nonlinear control strategy can improve transient stability of the multimachine power system.

Keywords: Flexible ac transmission system, power system, static synchronous compensation (STACOM), , fuzzy logic control, transient stability, Lyapunov, nonlinear control

Issue 6, Volume 11, June 2012

Title of the Paper: Short-Term Load Forecasting Method Based on Fractal Theory

Authors: Hongsheng Su

Abstract: In terms of the present short-term load forecasting(STLF) methods, whether the linear or the nonlinear, neither could meet the STLF requirements better with the rapid developments of electrical power systems and electrical power markets, and so a novel STLF method was proposed based on fractal theory in this paper. Firstly, the paper investigated the fractal characteristics of power system loads based on fractal theory, then gave out the calculating method of the correlative dimension and embedded dimension according to G-P algorithm. Next, the paper discussed the C-C algorithm and revised it, and then used it to work out the time-delay. Finally, the paper established the STLF model and put into practice. The simulation results indicate that the proposed method possesses higher precision, and is an ideal STLF predictor.

Keywords: Short-term load forecasting, Fractal theory, Embedded dimension, Reconstruction, G-P algorithm, C-C algorithm

Title of the Paper: A Highly Reliable Platform with a Serpentine Antenna for IEEE 802.15.4 over a Wireless Sensor Network

Authors: Chiu-Ching Tuan, Hung-Li Tseng, Yuan-Jen Chang, Chin-Hsing Chen, H.-D. J. Jeong, Wen-Tzeng Huang

Abstract: Wireless sensor networks (WSNs) are a developing area in the modern health-care service industry. Traditional circuit layout rules generally cannot be used for the stringent requirements of such systems due to unstable signals and non-ideal conditions. We propose and have implemented a hardware platform to eliminate the poor layout rules. During the design phase, our proposed design procedure can help analyze the signal propagation conditions of the printed circuit board (PCB) design by simulating board-level signal integrity. Moreover, this procedure leads to better layout rule parameters. A designer can effectively build a reliable hardware platform for the design of microcontroller unit schematics with superior system performance using our proposed layout rules. Such layout technologies are the major goal of original design manufacturers in their overall PCB designs. Moreover, since the PCB serpentine antenna has the advantages of low cost, light weight, simple construction, and easy integration, we used formulas and simulation software tools to analyze its characteristics and then constructed a prototype with better performance for IEEE 802.15.4 wireless antenna applications. Our experiments showed that the transmission distance can be greater than 18 m without any loss of data over a WSN when using this antenna.

Keywords: Wireless sensor network, ZigBee, IEEE 802.15.4, Signal integrity, Layout rules, Serpentine antenna

Title of the Paper: Coordinated Control of a Series-Parallel Hybrid Electric Bus During EV/HEV Mode Transition

Authors: Lei Wang, Yong Zhang, Jie Shu, Cheng-Liang Yin

Abstract: Hybrid electric buses have been a promising technology to improve fuel economy and vehicle drivability. Due to the distinct transient response characteristics between different power sources and the discontinuity of the transmitted clutch torque, the output torque fluctuations of hybrid powertrains and the resulting vehicle jerks may occur during mode transitions, especially for the transition from the EV (electric vehicle) mode to the HEV (hybrid electric vehicle) mode. Aiming at achieving a smooth transition from the EV mode to the HEV mode for a series-parallel hybrid electric bus, this paper proposes a transient control strategy to coordinate the diesel engine and the motors during the transition process. The EV/HEV mode-transition control strategy is developed according to the operating status of the clutch, and the engine throttle is restricted during the transition process. In this control strategy, a fuzzy adaptive inference system is developed to estimate the difference between the actual and target engine torques. Then, the estimated torque difference is incorporated with a sliding mode controller to regulate the output torques of the integrated starter generator (ISG)and the traction motor (TM) to reduce the torque fluctuations in the powertrain. A simulation is performed using a forward-facing HEV model to validate the effectiveness of the proposed control strategy, and the results show significant reductions in torque fluctuations and vehicle jerks during the EV/HEV mode transition.

Keywords: series-parallel hybrid electric bus; EV/HEV mode transition; transient response; fuzzy adaptive sliding mode control; coordinated control

Issue 7, Volume 11, July 2012

Title of the Paper: Advanced Design of TQ/IQT Component for H.264/AVC Based on SoPC Validation

Authors: A. Ben Atitallah, H. Loukil, P. Kadionik, N. Masmoudi

Abstract: This paper presents an advanced hardware architecture for integer transform, quantization, inverse quantization and inverse integer transform modules dedicated to the macroblock engine of the H.264/AVC video codec standard. Our highly parallel and pipelined architecture is designed to be used for intra and inter prediction modes in H.264/AVC. The TQ/IQT design is described in VHDL language and synthesized to Altera Stratix II FPGA and to TSMC 0.18μm standard-cells. The throughput of the hardware architecture reaches a processing rate up to 1070 millions of pixels per second at 171.4 MHz when mapped to standard-cells. In addition, a system on a programmable chip (SoPC) implementation and validation of the proposed design as an IP core is presented using the embedded Altera development board.

Keywords: H.264/AVC, video coding, FPGA, SoPC

Title of the Paper: Intelligent Ziegler-Nichols-Based Fuzzy Controller Design for Mobile Satellite Antenna Tracking System with Parameter Variations Effect

Authors: Jium-Ming Lin, Po-Kuang Chang

Abstract: This research applied both the traditional, Ziegler-Nichols-based and Ziegler-Nichols-based fuzzy control methods for mobile satellite antenna tracking system design. Firstly, the antenna tracking and the stabilization loops were roughly designed according to the traditional bandwidth and phase margin requirements. However, the performances would be degraded if the tacking loop gain is reduced due to parameter variations. On the other hand both Ziegler-Nichols-based PID-type and Ziegler-Nichols-based fuzzy controllers were also applied in the tracking loop for refinement. But we can find only the fuzzy controller were better for both low and high antenna tracking loop gains, and the tracking loop gain parameter variations effect can be reduced.

Keywords: Tracking Loop, Stabilization loop, PD-type Fuzzy Controller; PI Compensator

Title of the Paper: Intelligent Approach to Determine the Type of Objects with Low Effective Reflective Surface, Built with Stealth Technology

Authors: M. Kostova, V. Djurov

Abstract: A system with a module for statistical processing and a module based on fuzzy logic is developed to analyse the scattering field of complex objects with low effective reflectivity, built with Stealth technology. One of the tasks of the system is to determine the type of surface of the observed object (plane ?2) by analyzing emulative data obtained under certain laboratory conditions and parameters of probed signal. Data is manipulated for statistical processing, where every angle of azimuth, at a fixed angle position corresponds to a certain level of signal within the field of dispersion.

Keywords: Emulative data, amplitude, cubic spline, fuzzy logic, effective reflective surface, smooth and double-reflective surfaces

Issue 8, Volume 11, August 2012

Title of the Paper: Design of Low Power Full Adder Using Active Level Driving Circuit

Authors: K. N. Vijeyakumar, V. Sumathy, M. Nithya, C. Venkatnarayanan, V. Thiruchitrabala

Abstract: CMOS technology is approaching the nano-electronics range nowadays, but experiences some practical limits. High dynamic power dissipation and leakage current in deep submicron technologies contribute a major proportion of total power dissipation in CMOS circuits designed for portable applications. Consequently, identification and modeling of different components is very important for estimation and reduction of power dissipation in scaled CMOS circuits, especially for low power applications. As full adder (FA) forms one of the important unit of digital signal processing architecture , its design implementation is considered. The logic styles used in the design of CMOS full adder circuit have many limitations in terms of power and number of transistors. Pseudo NMOS-PT adder is designed with carry block in Pseudo NMOS logic for reducing dynamic power dissipation and sum block in pass transistor logic for reducing gate count. An Active Level Driving Circuit(ALDC) is proposed for driving the level restoring weak PMOS pull-up transistor. ALDC charges the gate of pull up PMOS transistor to Vdd for active low outputs, turning it to OFF . This reduces the leakage power dissipation thereby decreasing the total power dissipation. The proposed adder is designed using Tanner 7.0 and simulated using TSPICE. Fabrication technology used is 180nm. Performance analysis reveals that the proposed adder design fairs better than conventional static CMOS, CPL, CMOS-BBL and BBL-PT adders in terms of power, delay and power delay product (PDP). Design implementation with Carry Select Adder (CSLA) is considered to measure driving capability.

Keywords: CPL, TGA, hybrid adder, BBL-PT, Pseudo NMOS, Portable application

Title of the Paper: The Counterfeit Components V-I Characteristics Difference Study

Authors: Neumann Petr, Adamek Milan, Skocik Petr

Abstract: The electronic component V-I characteristics express a relationship between the current flowing via a chosen couple of pins, and the voltage applied on those pins. That voltage varies between two safe, for the component health limits, during the V-I characteristic recording. The applied voltage variation follows a certain function like sinus or ramp. The V-I characteristics of an individual component type can differ according to production technology, according to a particular manufacturer, or according to measurement conditions itself. Those so called natural differences can be registered by the study of statistically significant component population with known origin and history, and they can be subsumed in the comparison master pin print. That comparison master pin print is subsequently used as a criterion for discovering differences caused by improper treatment, failure or by the counterfeiting process. The article illustrates a counterfeit detector application for comparative V-I characteristics analysis aimed at a relevant knowledge base development for particular production technologies and component types.

Keywords: Counterfeit component, counterfeit detector, V-I characteristic, scan profile, pin print, comparison criteria, master component

Title of the Paper: A Novel Low Input Impedance Low Power Fully Differential Current Buffer with ±0.65V Supply Voltage and high bandwidth of 520MHz

Authors: Leila Safari, Seyed Javad Azhari

Abstract: A new fully differential (FD) low input impedance CMOS current buffer with low voltage, and low power operation is presented. The low input impedance is achieved by remarkable reduction of the input node voltage swing using a novel double feedback scheme. Some advantages of the proposed double feedback scheme over the conventional (either positive or negative) feedback techniques are: lower input impedance, robustness to process tolerances and a very simple and compact design. As a fundamental building block, this current buffer can also be used to implement such current mode circuits as current conveyors, current differencing buffered amplifiers (CDBA), current mode operational amplifiers, oscillators, filters and some voltage operational amplifiers (VOA). The proposed current buffer is designed and simulated with HSPICE using TSMC 0.18µm CMOS process parameters and supply voltage of ±0.65V. The simulated input impedance is 0.44Ω which shows a reduction factor of 6250 compared to the conventional common gate structure. It exhibits excellent -3dB bandwidth of 520MHz and low power consumption of 180µW which stem from its very simple structure. The proposed current buffer also exhibits high common mode rejection ratio (CMRR) of 90dB, very high positive and negative power supply rejection ratio (PSRR+/PSRR-) of 112dB and 143dB respectively which makes it very suitable for low voltage mixed mode applications. The corner case and Monte Carlo simulation results are also provided which proves the outstanding robust performance of the proposed current buffer against technology process tolerances.

Keywords: Low input impedance, Current Buffer, Current Conveyor, Constant bandwidth voltage amplifier, Current Amplifier, Current Mode, Dual Feedback

Issue 9, Volume 11, September 2012

Title of the Paper: Generic Stochastic Effect Model of Noise in Controlling Source to Electronically Controlled Device

Authors: Rawid Banchuin

Abstract: In this research, the stochastic model which describes the effect of noise in the controlling source to any electronically controlled devices has been proposed. The model is generic since it is applicable to any electronically controlled device either controlled by voltage or current. It is also realistic due to the Nth order approximation and the usage of the Gaussian process for modeling the noise. It can be seen from the verifications using the Monte-Carlo SPICE simulations and the Kolmogorov-Smirnov tests that this model can accurately capture the stochastic behaviour of such devices with as high as 99% confidences. Hence, it has been found to be a convenient tool for the precision analysis along with the high accuracy aimed design of various circuits and systems involving any electronically controlled devices.

Keywords: CMOS, electronically controlled device, Gaussian process, Kolmogorov-Smirnov tests, Monte-Carlo SPICE simulations, noise, stochastic process

Title of the Paper: Design and Analyse of Silicon Carbide JFET Based Inverter

Authors: Zheng Xu, Sanbo Pan

Abstract: This paper presents the design and testing of a high frequency, high efficiency inverter using silicon carbide (SiC) JFET power module. A rugged negative voltage gate drive circuit is used to solve the normally on problem of JFET devices and avoid the bridge shot-through during power on or power off. The circuit can provide over-voltage protection, over current protection and over temperature protection circuits to ensure the safe operation of the SiC JFET module and the resultant inverter system. The simulation and measurement results show that SiC JFETs have short turn-on and turn-off times, which will result in lower switching losses than silicon (Si) IGBTs. The low on-resistance in SiC JFETs will result in lower conduction losses. The experiment results of a 1kW SiC JFET-based inverter showed 3% efficiency improvement by a SiC JFET-based inverter over a Si IGBT- based inverter.

Keywords: Silicon Carbide, SiC JFET, inverter, gate drive

Title of the Paper: Optimizing Large-Scale Combinatorial Problems using Max-Min Ant System Algorithm

Authors: Aristidis Vlachos

Abstract: The maintenance scheduling of thermal generators is a large-scale combinatorial optimization problem with constraints. In this paper we introduce the Max-Min Ant System based version of the Ant System. This algorithm reinforces local search in neighborhood of the best solution found in each iteration while implementing methods to slow convergence and facilitate exploration.Max-Min Ant System (MMAS) algorithm has been proved to be very effective in finding optimum solution to hard combinational optimization problems. To show its efficiency and effectiveness, the proposed Max-Min Ant System is applied to a real-scale system, and further experimenting leads to results that are commented.

Keywords: Thermal Generator Maintenance Scheduling Problem, Ant Colony Optimization, Max-Min Ant System

Issue 10, Volume 11, October 2012

Title of the Paper: Self-Tuning PI-Type Fuzzy Direct Torque Control for Three-phase Induction Motor

Authors: José L. Azcue P., Alfeu J. Sguarezi Filho, Ernesto Ruppert

Abstract: In this article is proposed the Direct Torque Control (DTC) with Space Vector Modulation (SVM) based on Self-Tuning PI-Type Fuzzy (STPIF) controller. This controller determines dynamically the load angle between stator and rotor flux vectors and in consequence the electromagnetic torque necessary to supply the motor load. The rule base for STPIF controller is defined in function of the error and the change of the error of the torque using a most natural and unbiased membership functions (MF). Constant switching frequency and low torque ripple are obtained using SVM. Performance of the proposed DTC-SVM with STPIF are compared with the performance of the same scheme but using PI controller in terms of several performance measures such as settling time, rise time and integral-of-time multiplied by the absolute magnitude of the error index (ITAE). The simulation results show that the proposed scheme can ensure fast torque response and low torque ripple in comparison with DTC-SVM with PI controller.

Keywords: Direct Torque Control, Space Vector Modulation, Self-Tuning, Fuzzy Controller, Induction Motor

Title of the Paper: Switched-Current Techniques: An Overview of Cumulative SI-Related Errors on Dynamic and Static Performances of 2nd Order LP-ΣΔMs

Authors: Karim Abbes, Mohamed Masmoudi

Abstract: We present in this work a systematic analysis to identify Sigma Delta Modulators (ΣΔMs) nonidealities, such as charge injection error, I/O conductance ratio error and settling time error. A physical mechanism behind Switched Current (SI) errors is proposed. In the first time, errors mentioned above are treated separately and a behavioural model of SI cell is derived for each non-ideality. In the second time, we propose a behavioural model of Non-inverting Lossless Integrator. For typical variations of SI-related errors, simulations have been made using Matlab/Simulink. Finally we present their influences on both dynamic and static performances of the 2nd order SI Low Pass ΣΔMs (SI-LPΣΔMs).

Keywords: ADC converter, Switched Current technique, Sigma-Delta Modulator, error mechanisms, Dynamic and Static Performances

Title of the Paper: Development and Demonstration of 12.4 GHz SiGe HBT Mixer for Radio over Fiber Applications

Authors: Norliza Mohamed, Sevia Mahdaliza Idrus, Abu Bakar Mohammad, Syamsuri Yaakob

Abstract: This work involves in conveying of an optically modulated intermediate frequency (IF) over fiber by employing the frequency up-conversion technique at the base station (BS), while the local oscillator (LO) signal was assumed to be remote and was located at the central station (CS). The main focus of this work is the development of optical front-end receiver for radio over fiber (RoF), whereby the LO signal was sent from CS to BS using the system. At the BS, the optically generated LO signal was used to up-convert the IF signal by using a microwave mixer. The mixer was developed utilizing heterojunction bipolar transistor (HBT) as its main active component due to the high internal gain offered and to allow the frequency conversion to take place. HBT mixer configuration was successfully modeled and simulated by employing harmonic-balance technique in Microwave Office (MWO) software. It has been verified through fabrication and device demonstration. In which, with the driven LO power of 0 dBm, the simulated conversion gain of -2.8 dB to 5.2 dB was obtained at -30 dBm to -10 dBm of IF input power level. The design was practically demonstrated and up-converted RF signal of up to 12.4 GHz was achieved.

Keywords: Frequency up-conversion, RF mixer, up-conversion mixer, SiGe heterojunction bipolar transistor (HBT), radio over fiber (RoF), harmonic balance technique, remote local oscillator

Issue 11, Volume 11, November 2012

Title of the Paper: Development of Current-Fed ICPT System with Quasi Sliding Mode Control

Authors: Xiao Lv, Yue Sun, Zhi-Hui Wang, Chun-Sen Tang

Abstract: In current-fed inductively coupled power transfer (ICPT) systems, voltage distortions and current spikes are easily caused on the semiconductor switches especially when system-parameters vary. This increases the EMI level of the system and the switching loss as well. A quasi sliding mode control (QSMC) method is proposed to improve the dynamic performance of the system by optimization of frequency response. A mathematic model of the system is built up with stroboscopic mapping method and fixed-point theory is applied to get the accurate zero voltage switching (ZVS) frequency. Because of the phase delay caused by the feedback, control and driving circuits, an equivalent model for primary converter is built to figure out the time of phase compensation. Then the QSMC strategy is presented and implemented in developing a prototype current-fed ICPT system. Experimental test results have verified that the proposed control method can regulate the transition of the system to be smooth against wide parameters variations and the spikes on switches have been eliminated effectively.

Keywords: Inductively coupled power transfer, Quasi sliding mode control, Frequency response, Zero voltage switching, Stroboscopic mapping

Title of the Paper: Optimization of Gate - Source/Drain Underlap on 30 nm Gate Length FinFET Based LNA Using TCAD Simulations

Authors: K. K. Nagarajan, N. Vinodhkumar, R. Srinivasan

Abstract: The effect of gate – drain/source underlap (Lun) on a narrow band LNA performance has been studied, in 30 nm FinFET using device and mixed mode simulations. Studies are sssssdone by maintaining and not maintaining the leakage current (Ioff) and threshold voltage (Vth) of the various devices. LNA circuit with two transistors in a cascode arrangement is constructed and the input impedance, gain and noise-figure have been used as performance metrics. To get the better noise performance and gain, Lun in the range of 3-5nm is recommended.

Keywords: FinFET, LNA, TCAD, Underlap, Noise-Figure, Gain

Title of the Paper: Modelling of Characteristic Parameters for Asymmetric DHDMG Mosfet

Authors: Swapnadip De, Angsuman Sarkar, Chandan Kumar Sarkar

Abstract: A quasi-Fermi potential based analytical subthreshold drain current model for linear profile based DHDMG MOS transistor, incorporating the fringing fields at the two ends of the device, without the use of any fitting parameter as is the case with drift-diffusion approach is proposed. The model uses an average doping concentration expression. A pseudo-2D analysis applying Gauss' law along the surface is used to model the subthreshold surface potential. The same model is used to find the threshold voltage and drain current for Gaussian profile based DHDMG. A detailed comparison of the proposed Gaussian model with the previously proposed linear model is also presented. The proposed model is also compared with Double gate MOSFET and better performance in terms of DIBL effect reduction is observed. The results obtained are compared with a 2D device simulator DESSIS. Very good agreement of the results from DESSIS with those from the proposed model validates the model for suppressing the short channel effects.

Keywords: Drain Current; Threshold Voltage; Surface Potential; Pseudo Analysis; Halo; Dhdmg

Issue 12, Volume 11, December 2012

Title of the Paper: Real-Time On Line Tuning of Fuzzy Controller for Two Link Rigid-Flexible Robot Manipulators

Authors: Marwan A., Farrukh Nagi, Ksm Sahari, Hanim S.

Abstract: In this paper, a real time self-tuning MIMO fuzzy bang-bang controller (FBBC) is proposed to control two link rigid and flexible robot manipulators. Two link rigid and flexible robot manipulators are highly nonlinear plants. The fuzzy control is based on the Takagi-Sugeno?s type architecture fuzzy model combined with online self-tuning so that both the desired transient and steady state responses can be achieved. The online self-tuning is based on the gradient steepest descent tuning method, which learns to tune the FBBC?s inputs and outputs gains online. The controller operation is demonstrated by simulation of tracking ability and manipulator's positioning control with different payload. Based on the simulation results, the proposed controller shows good performance in tracking ability even with big payload.

Keywords: Rigid-flexible manipulators; Bang-Bang control; online self-tuning; Takagi-Sugeno; MIMO dynamic systems

Title of the Paper: Simulation and Realization of a Controlled Solar Water Heating System

Authors: Messaouda Azzouzi, Belkacem Attia, Nikos E Mastorakis, Amin Daneshmand Malayeri

Abstract: This paper describes a design and a realization of an example of solar energy exploitation systems; it is a simulation and a realization of solar water heating system with a control board based on the microcontroller PIC 16F877. The project is foremost simulated by ISIS-Proteus software and then realized in real time. The practical results of this application were carried out using a digital LCD which displays the hot water temperature. This temperature varies between the minimal value 20oC and its maximal value 70oC. The results prove the competitiveness of the solar hot water system with its controlling board. The economized coast of the realized project can help and encourages the use and may be the commercialization of this system.

Keywords: Control, Solar energy, Thermal, Solar water heater, PIC 16F877, Renewable energy, NTC.

Title of the Paper: Competent Universal Reversible Logic Gate Design for Quantum dot Cellular Automata

Authors: Kunal Das, Debashis De, Mallika De

Abstract: Quantum dot cellular Automata (QCA) is leading technology for alternative of CMOS design. Reversible Logic design is found to be Low power design which becomes emerging technology in Low power Nanotechnology era. In this work we devoted to design a Reversible Logic Gate which is a universal gate (known as URLG) and can be design with alternative of co-planer cross over wire. We introduce a passive type 3×3 tile that will also helpful for design the co-planner crossover wire, implements Reversible gate. We analyzed the application of passive type tile with the implementation of proposed URLG. The reversible gate design proposed in this paper which is proved to be universal by means of designing all classical logic gate i.e. AND, OR, NOT, NAND, NOR and XOR. During design of URLG we made attention is to reduce the no.’s of cells as well as to reduce the area which is found to be 0.16μm2 with conventional co-planner crossover wire and 0.19 μm2 area with new proposed passive 3×3 tile and compared to Fredkin gate it achieved 48%(on average) reduction in area (area of Fredkin gate is 0.37 μm2). We also tried made focus on ‘Garbage Minimization’ Problem. Here, we demonstrate that the design all Logic gate generate low garbage output as we make a comparison with NFT gate. We achieve 20% reduction in garbage count. The competent design of working Temperature, Fault Tolerant URLG is useful to implement all combinational Logic circuit as well as sequential circuit. Hence, it shall be innovative, effective with respect to previous report.

Keywords: Basic QCA, Majority Voter (MV), And-Or-Inverter (AOI), Reversible Logic Gate, Garbage Count