ides Editor

Abstract: Electrocardiogram (ECG) signal has been widely used for heart diagnoses .In this paper, we presents the design of Heart Arrhythmias Detector using Verilog HDL based on been mapped on small commercially available FPGAs (Field Programmable Gate Arrays). Majority of the deaths occurs before emergency services can step in to intervene. In this research work, we have implemented QRS detection device developed by Ahlstrom and Tompkins in Verilog HDL. The generated source has been simulated for validation and tested on software Verilogger Pro6.5. We have collected data from MIT-BIH Arrhythmia Database for test of proposed digital system and this data have given MIT-BIH data as an input of our proposed device using test bench software. We have compared our device output with MATLAB output and calculating the error percentage and got desire research key point of RR interval between the peaks of QRS signal. The proposed system also investigated with different database of MIT-BIH for detect different heart Arrhythmias and proposed device give output exactly same according to our QRS detection algorithm.

Abstract: Query driven Biclustering Model refers to the problem of extracting biclusters based on a query gene or query condition. The extracted biclusters consist of a set of genes and a subset of conditions that are similar to the query gene or query condition and it includes the query input also. Two approaches applied for biclustering problems are top- down and bottom-up, based on how they tackle the problems. Top-down techniques [3, 4] start with the entire gene expression matrix and iteratively partition it into smaller sub-matrices. On the other hand, bottom-up approach starts with a randomly chosen set of biclusters that are iteratively modified, usually enlarged, until no local improvement is possible. In this paper, the biological significance of biclusters extracted using two query driven models viz SIMBIC and SIMBIC+ are compared.This paper is organized as follows. Section 2 analyzes the popular MSB algorithm and section 3 introduces an improved version of MSB namely SIMBIC model and the enhanced model of SIMBIC namely SIMBIC+ is presented in section 4. The experimental analysis and the biological significance are illustrated in section 5.

Abstract: Separate digital signals are usually used as the digital watermarks. But this paper proposes rebuffed untrained minute values of vital image as a digital watermark, since no host image is needed to hide the vital image for its safety. The vital images can be transformed with the self attestation. Superior Self Organized Maps is used to derive self signature from the vital image. This analysis work constructs framework with Superior Self Organizing Maps (SSOM) against Counter Propagation Network for watermark generation and detection. The required features like robustness, imperceptibility and security was analyzed to prove that which neural network is appropriate for mining watermark from the host image. SSOM network is proved as an efficient neural trainer for the proposed watermarking technique. The paper presents one more contribution to the watermarking area.

Abstract: With ever increasing data in form of e-files, there always has been a need of a good application to search for information in those files efficiently. This paper extends the implementation of our previous algorithm in the form of a windows application. The algorithm has the search time- complexity of Θ(n) with no pre-processing time and thus is very efficient in searching sentences in a pool of files.

Abstract: In this paper, a new boost converter is introduced. In the proposed converter, a coupled inductor and voltage lift technique is used for raising the voltage gain .The designed converter especially for large voltage conversion ratio applications. By combining coupled inductor and voltage lift technique, the energy stored in the leakage inductor is recycled, therefore reduce the switch turn- off voltage and implement soft switching turn-on operation. The operating principles and steady-state analyses of continuous –conduction mode is discussed in detail. A 250W Converter Operating at 50KHZ with 25V input and 240V output simulation is presented to demonstrate the performance.

Abstract: For isolated applications, the 3- self-excited induction generator driven by wind energy source is more suitable, where the minimum excitation capacitance required for self-excitation of 3- induction generator is taken up in this work and the detailed analysis is carried out to determine the range of wind speed variation and consumer demand for the designed capacitance value. An electronic load controller is designed to maintain the load voltage constant for these variations. The excess power resulting as a consequence of rise in load voltage due to variation in load is pumped to dump load along with battery storage. Simulation for battery feeding the consumer load in the absence of wind power has been undergone. Exhaustive simulations have been carried out for such a scheme and the results have been presented in this paper.

Abstract: A nonlinear controller namely sliding mode controller has been designed for the modeled transfer function of DC shunt motor based Electric Vehicle Drive, which takes into account Vehicle parameters, Motor Parameters and Indian Road conditions. The performance analysis of PI controller as well as sliding mode controller based on trending law for the developed transfer function has been analyzed and quantified that sliding mode controller is better and robust for Electric vehicle suitable for Indian road conditions.

Abstract: Design of an intelligent pressure measurement technique by Capacitance Pressure Sensor (CPS) using an optimized Artificial Neural Network (ANN) is reported in this paper. The objectives of the present work are: (i) to extend the linearity range of measurement to 100% of input range, (ii) make the measurement technique adaptive to variation in physical parameters of diaphragm in CPS like, elasticity modulus and thickness, permittivity of dielectric constant, and temperature, and (iii) to achieve objectives (i) and (ii) using an optimized neural network. A suitable optimal ANN is added, replacing the conventional calibration circuit, in cascade to data conversion unit. The proposed measurement technique is tested considering variations in physical parameters of CPS, and temperature. These parametric variations are considered within the specified ranges. Results show that the proposed intelligent technique has fulfilled the objectives.

Abstract: Aviation safety has come a long way in over one hundred years of implementation. In aeronautics, commonly, requirements are Simulink Models. Considering this, many conventional low level testing methods are adapted by various test engineers. This paper is to propose a method to undertake Low Level testing/ debugging in comparatively easier and faster way. As a first step, an attempt is made to simulate developed safety critical control blocks within a specified simulation time. For this, the blocks developed will be utilized to test in Simulink environment. What we propose here is Processor in loop test method using RTDX. The idea is to simulate model (requirement) in parallel with handwritten code (not a generated one) running on a specified target, subjected to same inputs (test cases). Comparing the results of model and target, fidelity can be assured. This paper suggests a development workflow starting with a model created in Simulink and proceeding through generating verified and profiled code for the processor.

Abstract: A parallel approach to model Smart Environments in order to represent them efficiently has been presented in this paper. The focus of this research work is to achieve fast response during the dynamic retrieval of information in smart environments. The motivation here is to enable assisted living in an effective manner in smart home environments. Representation of smart environments includes the representation of the real-time data as well as representation of the system. Real-time data from the smart environment is represented here using the separate chaining hash table data structure while the smart environment is represented here using a variant of an existing membrane computing model referred to as the Distributed P System. The model proposed in this research work is designed to produce alerts spontaneously in the environment when abnormal activities are identified by a reasoning system that is assumed to be part of the smart environment. A prototype of the above model has been developed and it is capable of generating SMS alerts that can be sent to the occupant’s care taker for remote monitoring of the occupant.

Abstract: A multivariate approach involves varying number of objectives to be satisfied simultaneously in testing process. An evolutionary approach, genetic algorithm is taken for solving multivariate problems in software engineering. The Multivariate Optimization Problem (M OP) has a set of solutions, each of which satisfies the objectives at an acceptable level. Another evolutionary algorithm named SBGA (stage- based genetic algorithm) with two stages is attempted for solving problems with multiple objectives like cost minimization, time reduction and maximizing early fault deduction capabilities. In this paper, a multivariate genetic algorithm (MGA) in terms of stages for path-based programs is presented to get the benefits of both multi-criteria optimization and genetic algorithm. The multiple variables considered for test data generation are maximum path coverage with minimum execution time and test-suite minimization. The path coverage and the no. of test cases generated using SBGA are experimented with low, medium and high complexity object-oriented programs and compared with the existing GA approaches. The data-flow testing of OOPs in terms of path coverage are resulted with almost 88%. Thus, the efficiency of generated testcases has been improved in terms of path coverage with minimum execution time as well as with the minimal test suite size.

Abstract: In this article is presented a very simple and effective analog spiking neural network simulator, realized with an event-driven method, taking into account a basic biological neuron parameter: the spike latency. Also, other fundamentals biological parameters are considered, such as subthreshold decay and refractory period. This model allows to synthesize neural groups able to carry out some substantial functions. The proposed simulator is applied to elementary structures, in which some properties and interesting applications are discussed, such as the realization of a Spiking Neural Network Classifier.

Abstract: A Graphical User Interface (GUI) was developed for a user-friendly implementation of a water depth correction model. The Interactive Data Language (IDL)-based tool provides the prospective users with an interface that can be applied to perform water depth correction on hyperspectral images that contain shallow water bodies containing benthic habitat information. Users can select a pixel or a subset of a hyperspectral image to be corrected and define water correction for water depths of 0-2.0 m and for turbidity values of 0-20 NTU (Nephalometric Turbidity Unit) using the GUI. The results demonstrate that the GUI is an effective benthic mapping tool for shallow littoral areas; and it can be incorporated as a module in currently available commercial image processing software.

Abstract: Predictable execution enforcement for applications with highly and arbitrarily fluctuating resource usage requires runtime resource management. Correct runtime predictions regarding resource usage of individual components allows making proper resource reservations, enabling a better resource management of the component-based applications. This work presents a state-based resource usage model for a component, in which states represent CPU utilization intervals. This resource model is intended for a resource- aware component framework where it will be used to determine the quality of resource reservation. For this purpose, the model offers two metrics: failure rate, which measures the fraction of the reservation periods for which the reserved budget was insufficient, and resource waste, which measures unused budget.To illustrate the model, we apply it to a family of reser- vation prediction strategies and validate the outcome by means of a series of experiments in which we measure the resource utilization of two video components. The latter requires a method for monitoring resource states which is also presented, analyzed and validated in this paper.

Abstract: In this work, we are concerned with automatic synthesis and formal verification of interfaces between incompatible soft intellectual properties (IPs) for System On Chip (SOC) design. IPs Structural and dynamic aspects are modeled via UML2.x diagrams such as structural, timing and Statecharts diagrams. From these diagrams, interfaces are generated automatically between incompatible IPs following an interface synthesis algorithm. Interfaces behaviors verification is performed by the model checker that is integrated in Maude language. A Maude specification including interface specification and properties for verification are generated automatically from UML diagrams.

Abstract: Traffic rate estimation is an integral part of many high speed network services and components. Algorithms such as traffic conditioning, scheduling and admission control are dependent on accurate rate estimation. Several rate estimation techniques have been proposed however, the inherent bursty nature of Internet traffic, especially TCP traffic, does not allow for easy rate estimation. Short term changes may obscure output results or a change in traffic rate may not always be detected. Thus estimators may not always possess ideal characteristics of agility, stability and accuracy. As agility and stability are inter-dependent a single rate estimator cannot always be configured to be both agile and stable. In this paper a rate estimation technique is proposed that uses two rate estimation techniques to configure an agile estimator in measuring the actual changes of traffic in a timely manner as well as a stable one in ignoring short term variations of traffic. The performance of the proposed algorithm is analysed in comparison to that of an existing flip-flop filter using simulation analysis. Improved performance of the proposed estimator over that of the flip-flop filter is demonstrated using quantitative measures of agility, stability and accuracy. Existing TSW and EWMA algorithms are also investigated.

Abstract: Detection of breast cancer in its early stage is very important in the field of medicine. Optimal Contrast Enhancement is essential for the detection of mass and micro calcification in mammogram images. The standard histogram equalization is effective and simple method for contrast enhancement but for medical images most of the time it produces excessive contrast enhancement due to lack of control for the level of enhancement. In this paper image enhancement is considered as an optimization problem and an optimization technique based on entropy and edge information of the image is presented. The enhancement function used in the paper is Contrast Limited Adaptive Histogram Equalization (CLAHE) based on local contrast modification (LCM). Its enhancement potential is tested by sobel operator for the detection of microcalcification. Results are compared with other enhancement techniques such as Histogram Equalization, Unsharp Masking and CLAHE.

Abstract: There is an explosive growth of information in the World Wide Web thus posing a challenge to Web users to extract essential knowledge from the Web. Search engines help us to narrow down the search in the form of Search Engine Result Pages (SERP). Web Content Mining is one of the techniques that help users to extract useful information from these SERPs. In this paper, we propose two similarity based mechanisms; WDES, to extract desired SERPs and store them in the local depository for offline browsing and WDICS, to integrate the requested contents and enable the user to perform the intended analysis and extract the desired information. Our experimental results show that WDES and WDICS outperform DEPTA [1] in terms of Precision and Recall.

Abstract: The complete architecture with the necessary blocks and their internal structures are proposed in this paper. In this algorithm the complete variable precision format is utilized for the multiplication of the two numbers with a size of nxn bits. The internal multiplier is choosen for m bit size and is implemented using vedic-wallace structure for high speed implementation. The architecture includes the calculation of all the fields in the format for complete output. The exponent of the final result is obtained by using carry save adder for fast computations with less area utilization. This multiplier uses the concept of MAC unit, giving rise to more accurate results having a bits size of the final result will be 2n2.

Abstract: In this paper, we have designed a crawler that searches services provided by different clouds connected in a network. Proposed method provides details of freshness and age of cloud clusters. Crawler checks each router available in a network providing services. On basis of search criteria, our design generates output guiding users for accessing requested cloud services in efficient manner. We have planned to store the result in an m-way tree and to use traversal technique for extraction of specific data from the crawling result. We have compared the result with other typical search techniques.

Abstract: This paper focuses on Power Loss estimation in Electrical Sub Transmission and Distribution systems. The earliest empirical approaches were by Buller and Woodrow in 1928, Hoebel in 1959, M.W. Gustafson from 1983 to 1993. Gustafson changed the values of the coefficients and provided them with a constant loss term. It has been observed that this approach is not suitable for the present load scenario. In this paper, its successive approach has been proposed and tested with real time data. It has been concluded that the relationship between loss factor and load factor is not as complicated as perceived but easily understandable. By using exponential curve fitting, a relationship that is very close to reality can be obtained. To verify the obtained equation, data has been collected from a 33kV sub transmission line existing between 132kV/33kV Thurkayamjal substation and 33kV/11kV Hayathnagar substation, APTRANSCO, Andhra Pradesh.

Abstract: Among alternate sources of electricity, Solar Photo Voltaic (PV) energy is gaining prominence due to its plentiful availability. Water pumping is an important application of solar PV power. However people are not opting for it in large numbers as the ‘cost per watt’ for solar pumping systems is high. The cost can be reduced by harnessing more power per unit installed capacity of the solar panel. One method of realising this is by Maximum Power Point Tracking (MPPT) wherein a power electronic converter is used to match pump with the PV panel. Widely employed approach for MPPT is to monitor the PV panel power and keep on adjusting the duty cycle of converter so that tapped power is always maximum. Present paper proposes a novel method to realise MPPT for standalone solar PV water pumping system. It is shown that the output power becomes the maximum when the motor voltage becomes the maximum. Conversely, varying the duty cycle of the converter such that load voltage is always maximum leads to harnessing maximum power output. This approach can be referred to as Maximum Load Voltage Point Tracking (MVPT). We need to monitor only load voltage. It is simpler than monitoring PV panel power as in that case it’s necessary to measure both panel voltage and current and then find their product. The proposal of MVPT for realizing MPPT is substantiated by theoretical explanation considering two types of loads: Pure Resistance and Centrifugal Pump driven by Permanent Magnet (PM ) brushed DC Motor. The Matlab-Simulink based simulation is also carried out. Simulation results are found to be in close conformity with the theoretical findings.

Abstract: During intravenous anesthesia, anesthetic drugs must be administered at a suitable rate to prevent over dosing and under dosing in a patient. A developed Pharmacokinetic- Pharmacodynamic (PK/PD) model, which has been used to study the relationship between administered anesthetic dose and its effect on the patient in terms of hypnosis, is considered. In this paper, Linear Model Predictive Controller (LMPC) framework based on Active Set Method (ASM) with modified approach for closed loop control of intravenous anesthesia is presented for Single-Input (Propofol infusion rate) Single- Output (Bispectral Index (BIS)) model of a patient. Effectiveness of the designed LMPC has been studied for BIS reference tracking as well as constraints, disturbances and noise handling in the measured variables. Performance of proposed approach is compared with conventional Proportional-Integral-Derivative (PID) controller, considering closed loop time delays. Simulation result shows that, proposed LMPC outperforms conventional PID controller.

Abstract: The variable frequency transformer (VFT) developed recently is a flexible asynchronous ac link which is used to transfer power in-between asynchronous power system networks. The first VFT was installed at the Langlois substation, which interconnects the New York (USA) and the Hydro-Québec (Canada) systems. Basically, it is a rotary transformer whose torque is externally adjusted in order to control the power transfer. In the paper, a simulated model of VFT is present, which is used as a controllable bidirectional power transmission device that can control power transfer through the asynchronous power system networks. A digital simulation model of VFT and its control system are developed with MATLAB Simulink and a series of studies on power transfer through asynchronous power system networks are carried out with this model. M oreover, the response characteristics of power transfer under various torque conditions are discussed. Further voltage, current, torque and power transfer plots are also obtained. Thus, the VFT concept and its advantages are verified by simulation results.

Abstract: This paper presents an interior-point method (IPM) based quadratic programming (QP) solver for the solution of optimal control problem in linear model predictive control (MPC). LU factorization is used to solve the system of linear equations efficiently at each iteration of IPM, which renders faster execution of QP solver. The controller requires internal states of the system. To address this issue, a Proportional Integral Observer (PIO) is designed, which estimates the state vector, as well as the uncertainties in an integrated manner. MPC uses the states estimated by PIO, and the effect of uncertainty is compensated by augmenting MPC with PIO- estimated uncertainties and external disturbances. The approach is demonstrated practically by applying MPC to QET DC servomotor for position control application. The proposed method is compared with classical control strategy-PID control.

Abstract: Although designing and tuning a proportional- integral-derivative (PID) controller appears to be conceptually intuitive, but it can be hard in practice, if multiple (and often conflicting) objectives such as short transient and high stability are to be achieved. Traditionally Ziegler Nichols is widely accepted PID tuning method but it’s performance is not accepted for systems where precise control is required. To overcome this problem, the online gain updating method Augmented Ziegler-Nichols PID (AZNPID) was proposed, with the amelioration of Ziegler-Nichols PID’s (ZNPID’s) tuning rule. This study is further extension of [1] for making the scheme more generalized. With the help of fourth order Runge-Kutta method, differential equations involved in PID are solved which significantly improves transient performance of AZNPID compared to ZNPID. The proposed augmented ZNPID (AZNPID) is tested on various types of linear processes and shows improved performance over ZNPID. The results of the proposed scheme is validated by simulation and also verified experimentally by implementing on Quanser’s real time servo-based position control system SRV-02.

Abstract: This paper deals with the mechanism of space – vector pulse –width modulation (SVPWM) for a balanced two –phase induction motor ,in detail .It explains how the wave- forms of the voltages applied to the two phases derive from the SVPWM .

Abstract: This work represents a mathematical analysis and simulation of dc-motor electric drive control system with variable moment of inertia. A separately-excited dc motor is used in this control system. A mathematical model for this motor has been simulated and tested in Matlab/Simulink. A closed-loop control system for this dc electric drive system is proposed. The proposed control system is based on the technical optimum method of design. The controlled variable of this system is the load angular speed. In this control system the moment of inertia is considered to be variable. It varies as a function of time. A speed controller and a current controller are designed for the suggested model to meet the desired performance specifications by using the technical optimum method. These controllers are attached to the control system and the closed-loop response is observed by simulation and testing this model. The results show the high-performance of the designed control system.

Abstract: The classical method of power measurement of a system are iterative and bulky in nature. The new technique of measurement for bus voltage, bus current and power flow is a Phasor Measurement Unit. The classical technique and PMUs are combined with full weighted least square state estimator method of measurement will improves the accuracy of the measurement. In this paper, the method of combining Full weighted least square state estimation method and classical method incorporation with PMU for measurement of power will be investigated. Some cases are tested in view of accuracy and reliability by introducing of PMUs and their effect on variables like power flows are illustrated. The comparison of power obtained on each bus of IEEE 9 and IEEE 14 bus system will be discussed.

Abstract: The rapid growth in electronics, sensors and communication technology has made it possible to construct the WSN consists of large number of portable sensors. Because of this measurement accuracy of various parameters in the field has been increased. It has increased the quality of WSN. But due to the use of large numbers of portable sensor nodes in WSN, probability of sensor node failure gets increased. It has affected the reliability and efficiency of WSN. To maintain the high quality of WSN, detection of failed or malfunctioning sensor node is essential. The failure of sensor node is either because of communication device failure or battery, environment and sensor device related problems. To check the failed sensor node manually in such environment is troublesome. This paper presents a new method to detect the sensor node failure or malfunctioning in such environment. The proposed method uses the round trip delay (RTD) time to estimate the confidence factor of RTD path. Based on the confidence factor the failed or malfunctioning sensor node is detected. Hardware based simulation result indicates the easy and optimized way of detecting failed or malfunctioning sensor node in symmetrical WSN.

Abstract: In this paper, UWB technology operating in broad frequency range of 3.1-10.6 GHz has shown great achievement for high- speed wireless communications. to satisfy the UWB system requirements, a band pass filter with a broad pass band width, low insertion loss, and high stop-band suppression. UWB band-pass filter (BPF) with wireless local area network (WLAN) notch at 5.8 GHz and 3-dB fractional bandwidth of 108% using a microstrip structure is presented. Initially a two transmission pole UWB band pass filter in the frequency range 3.1-10.6 GHz is achieved by design a parallel-coupled microstrip line with defective ground plane structure using GML 1000 substrate with specification: dielectric constant 3.2 and thickness 0.762 mm at centre frequency 6.85 GHz. In this structure a ë/4 open circuited stub is introduced to achieve the notch at 5.8 GHz to avoid the interference with WLAN frequency with lies the desired UWB band. The design structure was simulated on electromagnetic circuit simulation software and fabricated by microwave integrated circuit technique. The measured VNA results show the close agreement with simulated results.

Abstract: Network-on-chip (NoC) is a new aspect for designing of future System-On-Chips (SoC) where a vast number of IP cores are connected through interconnection network. The communication between the nodes occurred by routing packets rather than wires. It supports high degree of scalability, reusability and parallelism in communication. In this paper, we present a Mesh routing architecture, which is called Diametrical 2D Mesh of Tree, based on Mesh-of-Tree (MoT) routing and Diametrical 2D Mesh. It has the advantage of having small diameter as well as large bisection width and small node degree clubbed with being the fastest network in terms of speed. The routing algorithm ensures that the packets will always reach from source to sink through shortest path and is deadlock free.

Abstract: In this paper, we propose a novel joint semi-blind channel and data estimation technique based on Whitening Rotation (WR) method for Rayleigh flat fading Multiple Input Multiple output (MIMO) channel using different receiver antennas combinations. Here we divide newly proposed technique in three steps. In the first step, we use conventional Whitening Rotation based semi-blind channel estimation technique, where MIMO channel matrix H can be decomposed as H=WQ H . Whitening matrix W can be estimated blindly using second order statistical information of received data and unitary rotation matrix Q can be estimated exclusively using Orthogonal Pilot Maximum Likelihood (OPML) algorithm. In the second step, data symbols can be estimated using estimated channel H and received output data by applying maximum likelihood data estimation method. Finally in the third step, Q can be re-estimated as a Q new using OPML algorithm by considering estimated blind data symbols itself as a pilot symbols for more statistical information of unitary matrix and perform final channel estimation H final=W Q new H . Simulation results are presented under 4-PSK data modulation scheme for two transmitters and different combinations of receiver antennas to support proposed novel technique and they demonstrate improved BER performance compared to conventional WR based optimal technique and Rotation Optimization Maximum Likelihood (ROML) based suboptimal semi-blind channel estimation technique.

Abstract: An innovative data-acquisition circuit for temperature monitoring and control is designed and interfaced to printer port of a web server computer. Further, an interactive web application program has been developed and kept running in the server computer for controlling the operation of the data-acquisition circuit. Authenticated clients can access the web based instrumentation system through Internet / Intranet.

Abstract: Nonlinear dynamics of a third order phase locked loop (PLL) using a resonant low pass filter in the face of continuous wave (CW) and frequency modulated (FM) input signals is examined. The role of design parameters of the loop resonant filter and the modulation index of the input FM signal on the system dynamics is studied numerically as well as experimentally. The occurrence of chaotic oscillations in the PLL is verified by evaluating some well-known chaos quantifiers like Lyapunov Exponents from the numerical time series data.

Abstract: In this paper, the near-far resistance of the minimum mean square error (MMSE) detector is derived for the multicarrier direct sequence code division multiple access (MC-DS-CDMA) communication systems. It is shown that MC-DS-CDMA has better performance on near-far resistance than that of DS-CDMA.

Abstract: The performance of M-ary optical code division multiple access (OCDMA) is analytically investigated in presence of chromatic dispersion. The study is carried out for single mode dispersion shifted and non dispersion shifted fibers. Walsh code is used as user address. The p-i-n photodetector is used for optoelectronic conversion process. In our proposed model 16 different symbols are modulated with different intensity levels and detected by direct detection technique. The numerical results show that, the reconstruction of the transmitted symbol is strongly dependent on the received symbols magnitude which is reduced by fiber length and symbol rate. It is found that the proposed OCDMA system shows better performance when dispersion shifted fiber is used as a communication medium.

Abstract: In this paper, an evolutionary optimization technique, Particle Swarm Optimization with Constriction Factor and Inertia Weight Approach (PSOCFIWA) is adopted for the complex synthesis of three-ring Concentric Circular Antenna Arrays (CCAA) with non-isotropic elements and without and with central element feeding. It is shown that by selection of a fitness function which controls more than one parameter of the array pattern, and also by proper setting of weight factors in fitness function, one can achieve very good results. For each optimal design, optimal current excitation weights and optimal radii are determined having the objective of maximum Sidelobe Level (SLL) reduction. The extensive computational results show that the CCAA designs having central element feeding with non-isotropic elements yield much more reduction in SLL as compared to the same not having central element feeding. Moreover, the particular CCAA containing 4, 6 and 8 number of elements in three successive rings along with central element feeding yields grand minimum SLL (-46.4 dB). Standard Particle Swarm Optimization (PSO) is adopted to compare the results of the PSOCFIWA algorithm.

Abstract: The popularity of compact sized antennas are increasing recently due to their significant properties such as, tiny size, high gain, impedance merely 50 &! and very low phase difference. To achieve this goal, in this paper a Triple Inverted-F Antenna (TIFA) is designed for the 5 GHz WLAN and Bluetooth applications and it operates between the wide frequency ranges 4.75-8.2 GHz. This antenna also provides lower gain variation with peak return loss of -35.14, -25.795 and -22.37 dB at 5.2, 5.5 and 5.8 GHz respectively. In addition, the size of the antenna is only 12×20 mm2.

Abstract: This paper represents the numerical simulations of high gain inverted-F and loaded inverted-F antennas (IFA) for WLAN/Wi-Fi applications. The dimensions of the antennas are 16×34, 21×34 and 26×34 mm2 in case of IFA, slightly loaded IFA (SLIFA) and heavily loaded IFA (HLIFA) respectively. The antennas contain a very good peak gain of 7.89, 8.11 and 8.15 dBi with less than 1.2, 1.0 and 0.8 dBi gain variation within the -10 dB return loss bandwidth for IFA, SLIFA and HLIFA respectively. Moreover the proposed antennas can provide more than the required bandwidths for WLAN/Wi-Fi operations at 2.4 GHz (2.4~2.484 GHz) band. In addition, the proposed antennas have achievable return loss and radiation characteristics. Due to the compactness of the antennas, they are promising to be embedded within the different portable devices employing WLAN/Wi-Fi applications.

Abstract: This paper presents a novel low profile inverted-FL antenna (IFLA) for worldwide interoperability for microwave access (WiMAX) applications by means of numerical simulation. The antenna has compact size of 9×20 mm2 and provides a wide bandwidth of 750 MHz (5150~5900 MHz) which covers the 5.5 GHz WiMAX applications. Moreover it has very high peak gain of 8.04 dBi with 1.38 dBi gain variation within the 10 dB return loss bandwidth. The VSWR of the proposed IFLA varies from 1.79849 to 1.91245 within the antenna 10 dB return loss bandwidth. The antenna provides peak return loss of -29.903 dB at 5.45 GHz and the input impedance of proposed IFLA is 47.8595 at 5.5 GHz.

Abstract: Synthesizing arrays with low sidelobe and pencil beam radiation profile is under investigation for decades. A variety of array structures are available, but the simplest and useful structure is that of a linear array. Here, two basic symmetric Linear Antenna Array structures are assumed. The required array structure is assumed to provide low sidelobe and pencil beam profile. Departure from a uniformity in current and location profile has shown quiet appreciable improvement in the radiation pattern. The simulations are carried out using Differential Evolution Algorithm employing Best of Random mutation strategy (DEBoR).

Abstract: The paper studies the dynamics of a conventional positive going zero crossing type digital phase locked loop (ZC1-DPLL) taking non-ideal responses of the loop constituent blocks into account. The finite width of the sampling pulses and the finite propagation delay of the loop subsystems are properly modeled mathematically and the system dynamics is found to change because of their influence considered separately. However, when these two are taken simultaneously, the system dynamics can be made nearly equivalent to that of the ideal system. Through an extensive numerical simulation a set of optimum parameters to overcome design limitations have been obtained.