Welcome to Journal of Theoretical and Applied Information Technology

Author:

Source:

Abstract

We describe the use of the discrete wavelet transform (DWT) for system identification. Identification is achieved by using a test excitation to the system under test (SUT) that also acts as the analyzing function for the DWT of the SUT’s output, so as to recover the impulse response. The method uses as excitation any signal that gives an orthogonal inner product in the DWT at some step size (that cannot be 1).We favor wavelet scaling coefficients as excitations, with a step size of 2. However, the system impulse or frequency response can then only be estimated at half the available number of points of the sampled output sequence, introducing a multirate problem that means we have to ‘over sample’ the SUT output. The method has several advantages over existing techniques, e.g., it uses a simple, easy to generate excitation, and avoids the singularity problems and the (unbounded) accumulation of round-off errors that can occur with standard techniques. In extensive simulations, identification of a variety of finite and infinite impulse response systems is shown to be considerably better than with conventional system identification methods. The variation of error with frequency is simulated in identification methods.

Author:

Source:

Abstract

In this paper a novel method for effectively denoising the extremely corrupted image by fixed value impulse noise using robust estimation based filter is proposed. The proposed algorithm classifies the pixels of localized window in to “corrupted” or “uncorrupted” and removes only corrupted pixels by robust estimation or by mean of the processed neighboring pixels. It is shown that the proposed filter effectively removes the impulse noise while preserving the good image quality. The visual and quantitative results prove that the performance of proposed filter in the preservation of edges and details is better even at noise level as high as 95%.

Author:

Source:

Abstract

This paper introduces artificial hybridization of DNA strands as a bio-inspired alternative for the evaluation of inference rules in a conventional expert system. Biological hybridization process is a binding event between two complementary DNA single strands that leads to the formation of a double-stranded helix. The proposed technique to detect the hybridization is based on direct comparison of data allowing a high degree of parallelism. It makes an approach to its implementation on a restricted and low-cost architecture like a commercial microcontroller instances.

Author:

Source:

Abstract

This paper deals with digital simulation of Class D inverter fed induction heater system. This system has an advantage like reduced volume and switching losses. The circuit operates under zero voltage switching. The circuit models are developed for the open and closed loop system and they are used for simulation studies. The simulation results of open and closed loop systems are presented.

Author:

Source:

Abstract

Clustering is a distribution of data into groups of similar objects. In this paper, Ant Colony Optimization (ACO) is proposed to improve k-means clustering. Though the k-means is one of the best clustering algorithm, the quality is based on the starting condition and it may converge to local minima. And an important point is, so far, the researchers have not contributed to improve the cluster quality after grouping. Our proposed method has two phases: in the first step, the initial seeds for k-means clustering are selected based on statistical modes to converge to a “better” local minimum. And in the second step, we have proposed a novel method to improve the cluster quality by ant based refinement algorithm. The proposed algorithm is tested in medical domain and shows that refined initial starting points and post processing refinement of clusters indeed lead to improved solutions.

Author:

Source:

Abstract

This paper presents the design of fuzzy controller for Unified Power Flow Controller to improve the transient stability performance of a power system. The fuzzy controller uses a numerical consequent rule base of the Takagi-Sugno type, which can either linear or non linear-producing control gain variation over a very range. A fuzzy logic power system stabilizer has been developed using speed and rotor angle deviation as controller input variables. The tuned stabilizer has been tested by performing non linear simulations using a synchronous machine-infinite bus model.

Author:

Source:

Abstract

The objective of the proposed research is to analyze the performance of designing a molecular computer. The performances are analyzed starting from molecular diodes to transistors, integrated chip, and very large scale circuit design with different organic materials. It overviews the properties like material compatibility, chemical registrant, dimension, temperature variation, specific heat, hybridization property, moulding shrinkage and tunneling effect etc. affect the performance in compare to our silicon level design. Further it enhance to DNA level design and analyze the advantages, disadvantages of various techniques of designing an optimum and powerful molecular computer with high speed and accuracy. Another objective of this research work to go for a total bench mark analysis to silicon based computer, organic molecule based computer and biological based DNA Computer with a paradigm approach to performance factors. It reflects a standard formula to go for a speed, accuracy and memory of processor taking into different performance factors.

Author:

Source:

Abstract

Multicast network support is becoming an increasingly important technology for both military and commercial distributed and group based applications. The security services such as confidentiality, authenticity and data integrity are necessary for both wired and wireless networks to protect basic applications. In this paper we present a simulation based study of the impact of different types of attacks in mobile ad hoc networks. We consider the most common type of attacks namely Gray hole attack and Worm hole attack. Specifically, we study how these attacks affect the performance metrics of a multicast session such as packet delivery ratio, packet latency and packet-consumed energy.

Author:

Source:

Abstract

Atmospheric Signal processing has been one field of signal processing where there is a lot of scope for development of new and efficient tools for Cleaning of the spectrum, detection and estimation of the desired parameters. Atmospheric signal processing deals with the processing of the signals received from the atmosphere when manually stimulated using atmospheric Radar.The signals, which processed in the present work, have been obtained from the mesosphere-stratosphere- troposphere(MST) Radar. The MST radar facilities are situated at National Atmospheric research Laboratory, Gadanki, and Tirupati, INDIA. The signal processing done in the present work concentrates mainly on the data collected from NARL located at Gadanki. This project deal with signal processing techniques. for the analysis of MST Radar signal and to extract better information about moments for wind profiler. The proposed algorithm estimates wind profiler moments and signal –to –noise ratio. The performance of this method is tested practically with atmospheric ,wind profiler data collected at NARL, Gadanki, INDIA. Signal processing of recoded experimental data is performed by MATLAB code developed in my project ,and some of the graphs were plotted.

Author:

Source:

Abstract

The watermarking techniques for grayscale images can be easily extended to handle color images, for this purpose, watermark casting is done by generating three different watermark patterns SR, SG, SB, one for each RGB channel and modifying for each channel, the intensity of the pixels that belong to the corresponding sets AR, AG, AB. The watermark casting and detection procedures for color images are exactly the same as for the corresponding procedures for grayscale images. Instead of marking the three R, G, B components we can choose to mark the luminance and the chrominance components of the image. In this paper A Block Complexity based Data Embedding (ABCDE) watermarking technique, for color images in Spatial Domain, is considered for implementation and the performance analysis is done on the basis of different performance measures for various types and formats of images.