Girish Parmar

System order reduction using GA for unit impulse input and a comparative study using ISE & IRE

In this paper, the authors present an algorithm in which the application of Genetic algorithm has been shown in the order reduction of linear time invariant dynamic systems. The reduction algorithm is based on minimization of the integral square error by Genetic algorithm pertaining to a unit impulse input. The algorithm is simple, rugged and computer oriented. It is shown that the algorithm has several advantages, e.g. the reduced order models retain the steady-state value and stability of the original system. Two numerical examples are also given to illustrate the superiority of the proposed algorithm over some existing methods. The comparisons between the proposed and the other well-known existing order reduction techniques have been shown by comparing the ISE and IRE of various reduced order models.

Audio watermarking by spreading echo in time domain using pseudo noise gray sequence

Digital multimedia technology has shown a significant progress day to day in various fields such as entertainment, computer vision, security etc. hence, the distribution and use of multimedia data is much easier and faster. In such an open environment, it is convenient to get the access to various information sources. In present time, several issues are arising such as information security, information authentication, ownership or copyright protection with multimedia contents. Therefore, watermarking is breakthrough technique for resolving these issues for digital multimedia content like image, audio and video. In this paper, to improve the weak points of conventional echo hiding and overcome the problem of less security, we propose an audio watermarking technique based on pseudo-random gray sequences as a confidential key. To satisfy and maximize both imperceptibility and robustness, proposed audio watermarking algorithm based on pseudo-random gray sequences embed multi bits by spreading echo in time domain. The imperceptibility and the robustness of proposed audio watermarking are tested using various attacks and by listening test.

Application of Stochastic Fractal Search in order reduction of large scale LTI systems

Order reduction of large scale single-input single-output (SISO) linear time invariant (LTI) systems using stochastic fractal search (SFS) algorithm has been presented. Stochastic Fractal Search (SFS) is a metahuristic algorithm growth using the concept of fractal. SFS employs the diffusion property observed in random fractals to explore the search space. Stochastic rules like; Gaussian walks are used to change the iteration process to generate random fractals. Here, for order reduction of LTI system, SFS Algorithm is used. Integral square error (ISE) in between the transient responses of original higher order and reduced order system has been taken as an objective function, which has been minimized. The step and frequency responses of both low and high order systems have also been compared along with the transient responses parameters. A comparative study of ISE with the other existing techniques in the literature has also been given in the tabular form to show the superiority of the algorithm.

Design of frequency reconfigurable microstrip patch antenna for S-Band and C-Band applications

This paper presents a technique of microstrip patch antenna for S-band and C-band applications. In this proposed work the frequency reconfigurable microstrip patch antenna with three slots on the ground is proposed. In this there are two switches (copper strip) are placed on the slot at the ground plane to produce three different frequency bands at 3.06, 3.26 for (S-Band) and 4.27 GHz(C-Band) respectively. The proposed antenna is simulated using FR-4 substrate with permittivity 4.1 and substrate thickness 1.5 mm. The simulation of the proposed work is conducted with CST. The simulation result shows good directional radiation pattern and the directivity. The simulation result are indicating that the proposed antenna has good impedance matching at every band.

Parabolic shape ground plane having T-slots directional UWB antenna for airborne radar system

A novel design technique of parabolic shape ground plane directional ultra-wideband (UWB) with circular patch antenna for airborne radar system is being presented here. The feed for the proposed directional ultra-wideband antenna is given by microstrip line and T-slots are inserted diagonally at the corners of parabolic ground plane in order to increase the directivity. The simulation analysis of the antenna is done on software CST Microwave Studio using FR-4 substrate with dielectric constant 4.3. The simulated results have shown a good return loss with respect to -10 dB. The radiation pattern characteristics and surface current distributions of the antenna at different frequencies are also given.

Order reduction of linear continuous time interval system using mixed evolutionary technique

Higher order systems are difficult to control and complex in nature hence, it is desirable to reduce these systems in the low order system. A system with constant coefficient but uncertain within finite range is known as interval system. This paper aims to reduce linear continuous time interval system using evolutionary technique. Cuckoo optimization algorithm technique has attracted vast attention among various evolutionary techniques. The Routh array is constructed to obtain denominator of higher order system using the generalized routh table. The numerator of reduced order system is obtained using cuckoo optimization algorithm by minimizing integral square error between original and reduced order system. Reduced order system retains the stability and steady state value of the higher order system. The numerical examples are illustrated and results are compared with the other well known methods.

Design reconfigurable tapered slot antenna

A Tapered slot antenna with reconfigurable frequency band is presented in this paper. This tapered slot antenna contains two switchable rectangular slot. The notch band is achieved by a function of diode. A wide bandwidth mode from 3.2-9.5 GHz and narrowband mode can be selected. The pin diodes are used to reconfigure the impedance match and modify the radiation pattern. Measured results shows good performance of the proposed designs.

An Effective Way to Hide the Secret Audio File Using High Frequency Manipulation

As the technology increases day by day, human dependency increases on technologies. In present scenario everyone wants to do their work, business etc with the help of computer or with internet. Hence this increases the possibility of large-scale unauthorized copying which may lead to undermine the music, film, book and software industries. These concerns over protecting copyright have triggered significant research to find ways to hide copyright messages and serial number into digital media. An important sub discipline of information hiding is Watermarking. Digital Watermarking is an authentication technique which permanently embeds a digital signal (watermark) in text, image, audio, video files (any Data) by slightly modifying the data but in such a way that there are no harmful effects on the data. In this paper, we present audio watermarking technique that utilized the manipulation in high frequency of an audio signal to hide secret message The experimented result developed through MATLAB show that the usefulness of this technique.

Linear Multivariable System Reduction Using Particle Swarm Optimization and A Comparative Study Using Relative Integral Square Error

An algorithm for order reduction of linear multivariable systems has been presented using the combined advantages of the dominant pole retention method and the error minimization by particle swarm optimization technique. The denominator of the reduced order transfer function matrix is obtained by retaining the dominant poles of the original system while the numerator terms of the lower order transfer matrix are determined by minimizing the integral square error in between the transient responses of original and reduced order models using particle swarm optimization technique. The reduction procedure is simple and computer oriented.The proposed algorithm has been applied successfully to the transfer function matrix of a 10 th order two-input two-output linear time invariant model of a practical power system. The performance of the algorithm is tested by comparing the relevant computer simulation results.

Compact Low-Profile WiMAX-MIMO Antenna with Defected Ground Structure for Disaster Management

This paper presents a novel, compact, and low-profile 2 × 2 multi-input multi-output (MIMO) antenna for WiMAX 802.16a applications which is very useful for disaster communication systems. Proposed WiMAX-MIMO antenna designed on low cost FR4 substrate with the compact size of 32 × 32 mm2 with dielectric constant of 4.4. The defected ground structure perturbed in the form of L-shaped in the ground plane offer a good isolation up to −26 dB for the entire frequency band of 3–14 GHz. The two patches on the top of substrate perpendicular to each other introduced pattern diversity in the radiation pattern. The good impedance bandwidth of 0–14 GHz, high isolation and low correlation coefficient make the proposed design antenna suitable for WiMAX 802.16a applications.