Levinson Durbin Algorithm-An Approach for feature extraction of Red Palm Weevil

Vol. 3 No. 1

Year: 2012

Issue: Sep-Nov

Title: Levinson Durbin Algorithm-An Approach for feature extraction of Red Palm Weevil  

Author Name: Betty Martin, Vimala Juliet 

Synopsis: 

Digital audio information has become an important application of computer in the field of audio processing and pattern recognition. In pattern recognition, features are extracted from raw audio data. In this paper, an effective algorithm is proposed to extract features of the acoustic activity  of red palm weevil recorded in coconut grooves using Linear predictive coding.  The linear predictive coefficients characterize the audio content. Red palm weevil is an economic pest, the infestation of which, at an early stage can prevent total damage of the palm. The detection and infestation of this insect is possible only  by capturing the sound produced by the insect, using a reliable digital voice recorder. The sound acquired is further processed to confirm whether it belongs to the insect or not. This can be accomplished by a technique called Linear Predictive Coding. The coefficients extracted can further be matched by training data. The classification depends on the ability to accurately categorize each feature vector set corresponding to its own kind. This application is often used for sound identification or sound verification. In this article, a summary of work done to extract feature of the weevil which was later used to determine its presence on palms, has been done.

Comparison of Phase Shifted PWM Techniques for Cascaded Multilevel Inverter

Vol. 3 No. 1

Year: 2012

Issue: Sep-Nov

Title: Comparison of Phase Shifted PWM Techniques for Cascaded Multilevel Inverter 

  

Author Name: K C DEEKSHIT KOMPELLA  

Synopsis: 

This paper deals with comparison of various Phase shifted Pulse width modulation techniques like Phase Shifted carrier, Hybrid Phase shifted carrier and newly proposed Hybrid Phase shifted carrier Pulse width modulation techniques. Comparison is done in terms of their design and their operation.

QAM and OFDM - An Analysis of their Noise and Multipath Immunity through Simulation

Vol. 3 No. 1

Year: 2012

Issue: Sep-Nov

Title: QAM and OFDM - An Analysis of their Noise and Multipath Immunity through Simulation  

Author Name: Eiman Mutwali Abdelmageed Hussain  

Synopsis: 

In wireless communication systems, the transmitted signal is subject to different channel impairments, such as noise and multipath propagation. The demand for more reliable and higher speed wireless services has led to the development of digital communication techniques. This new development direction resulted in an increasing interest in new modulation formats that overcome the limitations associated with the wireless communication channel which degrades the performance of the communication system. The new sought modulation formats are expected to have high spectral efficiency and better immunity to transmission impairments. Of these modulation formats are the Quadrature Amplitude Modulation (QAM) and the Orthogonal Frequency Division Multiplexing (OFDM). This paper analyses through computer simulation the performance of: QAM, OFDM and QAM combined with OFDM under different channel impairments and compares which technique gives better performance under these conditions. The analysis was carried out using MATLAB and the results showed that QAM is used to effectively increase the channel capacity while OFDM is attractive because of its effective way in reducing the effect of inter-symbol interference (ISI). Furthermore a combination of these techniques has been proven to enhance the performance of a communication system.

Analytical Approach to Analyze Mode Fields in Arbitrary Index Fibre with Non Circular Geometry

Vol. 3 No. 1

Year: 2012

Issue: Sep-Nov

Title: Analytical Approach to Analyze Mode Fields in Arbitrary Index Fibre with Non Circular Geometry

Author Name : S. K. Raghuwanshi, MANDEEP SINGH  

Synopsis : 

In this paper elliptic cylinder coordinate system is used for the representation of modes in the core of non circular fibre. The scalar wave equation is converted to the elliptical coordinate system and the WKB method is applied for the calculation of fields. The author’s try to develop analytical approach to analyze non circular geometry having an arbitrary refractive index. The result obtained in this paper have been already discussed by the several researcher’s but these research paper lack with the detailed mathematical derivation to achieve some specific equations. The attempts in this paper is to show all the intermediate steps of existing results, which will useful for the beginner, who wants to gain the working knowledge in this area[1]. The result obtained in this paper can be easily extended to obtain the graphical or simulation results for non trivial cases.

Experimental verification on reduction of EMI in ZVS push-pull DC to DC converter system

Vol. 3 No. 1

Year: 2012

Issue: Sep-Nov

Title: Experimental verification on reduction of EMI in ZVS push-pull DC to DC converter system
 

Author Name: S.Devikala, P. Nirmalkumar

Synopsis:

This paper presents the experimental verification of ZVS push-pull converter. The emphasis of this topology is to reduce the electromagnetic interference, conduction losses, and complexity of the circuit. EMI caused by power converters can disturb the normal operation of the converter and other adjacent systems. The main aim of the research work is reduction of EMI in switching power converters. Lessening techniques have been explored to reduce EMI noise effectively. The push-pull converter is used as DC-DC converter suitable for low and medium power application. High efficiency, less switching loss and high power density are the incentives of this application. The switching frequency is increased to achieve high power density which will minimize the complexity of the circuit as size of the components reduced. Thus switching loss has to be minimized to achieve high frequency operation; this can be achieved by ZVS resonant techniques. This reduces switching losses as well as EMI.The push pull DC to DC converter with EMI filter is constructed and tested. The experimental results are compared with simulation results.