i-manager's Journal on Electronics Engineering (JELE)


Volume 2 Issue 2 December - February 2012

Research Paper

Contributions to Computational Algorithms for Stiff Lyapunov Differential Equations

Chiu Choi*
Professor, Department of Electrical Engineering, University of North Florida, Jacksonville, FL, USA.
Chiu H. Choi (2012). Contributions to Computational Algorithms for Stiff Lyapunov Differential Equations. i-manager’s Journal on Electronics Engineering, 2(2), 1-10. https://doi.org/10.26634/jele.2.2.1621

Abstract

A discretization method based on the backward differentiation formulas was applied to a stiff Lyapunov differential equation and transformed it into an algebraic Lyapunov equation such that numerically stable method could be applied to compute the numerical solutions. The discretization method allowed the use of variable step size selection strategies in the integration of the matrix differential equations. One such strategy was proposed in this paper. A feature of the strategy is that it permits moving through the interval of integration rapidly in the steady state of the stiff Lyapunov differential equations without exceeding the specified error tolerance. In order to test the accuracy of the discretization method and the proposed step size selection strategy, a stiff Lyapunov differential equation of variable size n×n with known closed form solution was developed. Such an equation is useful not only in this paper but also in the verification of the accuracy of future proposed algorithms for computing the numerical solutions of stiff Lyapunov differential equations. The discretization method was applied to this stiff Lyapunov differential equation with known closed-form solution. The numerical solution computed at every time step was compared with the closed form solution such that the accuracy of the computed solution can be known precisely. Eighteen case studies were conducted in the investigation. The findings were that the discretization approach was a viable method for solving stiff Lyapunov differential equation and the step size control strategy permitted rapid increase of step size of integration in the steady state of the stiff equation.

Research Paper

Color Image Compression using Wavelet, Ridgelet and Curvelet Transform

M. Sreekanth Reddy* , T. Ramashri**
* M. Tech student, Department of Electronics and Communication Engineering, S.V. University College of Engineering, Tirupati, A.P. India.
** Associate Professor, Department of Electronics and Communication Engineering, S.V. University College of Engineering, Tirupati, A.P. India
M. Sreekantha Reddy and T. Ramashri (2012). Color Image Compression Using Wavelet, Ridgelet And Curvelet Transform. i-manager’s Journal on Electronics Engineering, 2(2), 11-16. https://doi.org/10.26634/jele.2.2.1622

Abstract

Image Compression is a widely addressed research area. Many compression standards have been in place. But still there is a scope for higher compression with quality reconstruction. The introduction of wavelets gave a different dimension to the compression. But there are some limitations of wavelets while handling the line and curve singularities in the image. There are transforms beyond wavelets namely-Curvelet and Ridgelet Transforms. This paper aims at the analysis of color image compression using Wavelet, Ridgelet and Curvelet Transform. The Curvelet Transform gives better performance in terms of PSNR. Wavelet performs the least and is also affected by the blocking artifacts. Ridgelet is designed to handle line and edge singularities, where as Curvelet is designed to handle singularities on curves. By selecting proper thresholding method, better results for PSNR have been obtained. Color images in the YCbCr color model are used.

Research Paper

Power MOSFET in Automobile Application

D. S. Dhote* **
*-*** Professor, Department of Electronics, Brijlal Biyani Science College, Amravati, India.
** Associate Professor, Department of Electronics, Garware College, Pune, India.
D.S. Dhote, R.S. Rajuskar and G.D. Agrahari (2012). Power MOSFET in Automobile Application. i-manager’s Journal on Electronics Engineering, 2(2), 17-22. https://doi.org/10.26634/jele.2.2.1623

Abstract

This paper focuses on the simulation Power mosfet inverter driving the electrical motors such as PMBLM used in automotive power electronic systems to ensure energy efficiency . Today Power mosfets  are available  with high voltage , high power , high frequency ,protection against avalanche and short circuit behavior.  Control techniques such as Six- Step, SPWM, SVPWM are used for simulation and advantages of  the  drive are confirmed  with the simulation results.

Research Paper

Modeling the Quality of Service Rerouting in Cognitive Network

Y. B. Gandole*
Department of Electronics, Adarsha Science J.B.Arts and Birla Commerce Mahavidyalaya, Dhamangaon, India.
Y.B. Gandole (2012). Modeling the Quality of Service Rerouting in Cognitive Network. i-manager’s Journal on Electronics Engineering, 2(2), 23-35. https://doi.org/10.26634/jele.2.2.1624

Abstract

The cognitive behavior based on the cognitive science model for the network nodes to benefit the Quality of Service rerouting is designed. A Quality of Service rerouting protocol oriented to cognitive network is proposed. Rerouting is a distributed protocol where the route search is in a hop by hop way. Inspired by the small-world phenomenon, the experiential route information is collected and stored at each node to benefit the future route selection. We implement and evaluate Quality of Service rerouting in NS2 platform. Its performance is compared with another two popular routing protocols. The results show that Cognitive Rerouting has achieved remarkable performance improvements over the protocols where no cognitive behaviours are exploited.

Research Paper

Implementation Of Maximum Boost Control Switching Strategy For Impedance Source Inverter

R. Uthirasamy* **
* Assistant Professor, Department of Electrical & Electronics Engineering, Jansons Institute of Technology, Coimbatore.
** PG Scholar, Department of Electrical & Electronics Engineering, Sasuri Engineering College, Vijayamangalam.
R. Uthirasamy and C. Suganya (2012). Implementation of Maximum Boost Control Switching Strategy for Impedance Source Inverter. i-manager’s Journal on Electronics Engineering, 2(2), 36-42. https://doi.org/10.26634/jele.2.2.1625

Abstract

This paper presents a new topology of uninterruptible power supply (UPS) by using an extended boost Z-source inverter.In this project a new topology of uninterruptible power supply (UPS) implemented using extended boost source inverter. The Z-source concept can be applied to all dc-to-ac, ac-to-dc, ac-to-ac, and dc-to-dc power conversion. The extended boost Z-source inverter overcomes the conceptual and theoretical barriers and limitations of the traditional voltage source; current source and normal Z-source inverter. With this new topology, the proposed UPS can maintain the desired ac output voltage with reduced voltage drop and minimized voltage stress. The overall cost of the system has been reduced by reducing the battery utility. So, this system is more economical for UPS application. The proposed system is simulated using MATLAB / SIMULINK with the simple boost control scheme and various factors such as output voltage, boost factor and THD are analyzed.

Research Paper

Step Discontinuity Analysis in an Asymmetric Single Mode Thin Planar Slab Taper Optical Waveguide

S. K. Raghuwanshi* , Santosh Kumar**
*-** Department of Electronics Engineering, Indian School of Mines, Dhanbad, India.
Sanjeev Kumar Raghuwanshi and Santosh Kumar (2012). Step Discontinuity Analysis In An Asymmetric Single Mode Thin Planar Slab Taper Optical Waveguide. i-manager’s Journal on Electronics Engineering, 2(2), 43-48. https://doi.org/10.26634/jele.2.2.1626

Abstract

We study the thin taper optical waveguide structure by using the step discontinuity model. The technique presented is unique and not being discussed elsewhere. We also study the power loss due to step discontinuity effect for the case of an asymmetric single mode planar slab taper waveguide structure. The only assumption, we consider is that there are no reflection of fields at the step discontinuity point. In this paper we also assume that there are no mode conversions due to discontinuity effect and the structure maintain the single mode operation even at the step discontinuity point. We deliberately considered the thin taper structure to be valid on single mode operation. The technique presented can be easily extended to more complicated waveguide structure like ridge waveguide structure.