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Patna, India

Kumar D.,Maharaja Agrasen Institute of Technology | De A.,NIT Patna
2013 IEEE MTT-S International Microwave and RF Conference, IMaRC 2013

In this paper a new design of periodic structure has been proposed. These periodic structures are stepped impedance open circuited stubs loaded on a 50 ohm microstrip line. On the ground plane of microstrip periodic rectangular slots are made. These slots are responsible for the enhancement of insertion loss characteristics and give wider stop band characteristic. The period of the structures loaded on the microstrip line and the period of the slots on the ground plane are having same dimensions. For the desired center frequency the unit cell of the periodic structure is designed and then loaded periodically on the microstrip line. The proposed structure is applied to design a narrow band pass filter for the center frequency 3 GHz. The design procedure is elaborated and analysis of periodically loaded microstrip line is also given in this article. The design procedure is simple and there is no fabrication problem due to strong coupling. © 2013 IEEE. Source

Bhattacharya S.,NIT Patna
International Conference on Computing, Communication and Automation, ICCCA 2015

This paper intends to present an approach to classify different types of faults and to identify the location of the faults in a non-radial power system network using ElectroMagnetic Transients Program(ATP/EMTP)software and Artificial Neural Network(ANN). Firstly, a balanced three-phase system is designed with a RLC load and then different types of faults(single line to ground fault, line to line fault, double line to ground fault and three phase fault) are created at various points of the transmission line. The transmission line model is simulated using the EMTP software. The resulting current waveforms under different fault conditions are observed from the sending end. Fault occurs at the point where peaks appear in the current signal when viewed from the sending end. These current waveforms are analyzed using the wavelet toolbox in MATLAB and the entropy values of the current signals, so obtained, are given as input to the artificial neural network for automatic fault classification and identification of the faulty line. This scheme is also tested under different types of faults with different fault resistances and varying fault locations and the results show that it is able to discriminate the faults and identify the fault locations rapidly and correctly. © 2015 IEEE. Source

Dawar P.,Guru Tegh Bahadur Institute of Technology | De A.,NIT Patna
Advances in Optical Technologies

This paper adumbrates a novel tunable metamaterial consisting of triangular split ring resonator (TSRR) and wire strip (WS) at THz frequency. Ansoft high frequency structure simulator (HFSS) has been used to design and analyse the metamaterial having Rogers RT/duroid 5870 (εr = 2.33) and FR4 (εr = 4.4) as substrate material. Nicolson Ross Weir (NRW) method has been used to retrieve the material parameters from transmission and reflection coefficient. 4% maximization has been obtained in the location of the negative region (or resonance frequency for permeability) by using FR4 with 0.75 m instead of 1.25 m as substrate thickness. In addition, 18% minimization has been achieved by using FR4 with 0.25 m instead of RT/duroid 5870 substrate with the same thickness. Tunability has been proved by showing dependence of resonant frequency over the substrate thickness and substrate material. © 2014 Parul Dawar and Asok De. Source

Mishra S.S.,NIT Patna | Krishna P.,Indian Institute of Technology Roorkee
Proceedings of the Institution of Civil Engineers: Bridge Engineering

Cable-stayed bridges are prone to wind-induced instabilities owing to their smaller frequencies. Further, because of the closeness of torsional and vertical bending frequencies they are more likely to suffer from classical flutter. In this paper, empirical formulae have been proposed for estimating the basic frequencies as well as the flutter critical wind speed. Corroborative examples of a few cable-stayed bridges of different spans, namely, Karkinen, Nanpu, Yangpu and Oresund, have been considered. The flutter critical speeds of these bridges by the proposed method have been compared with those obtained from Selberg's formula and the Chinese method. Lastly, based on the safety margins with respect to the critical flutter speeds, cable-stayed bridges have been categorised into three groups, and the need for wind tunnel tests has been proposed. It is expected that the approach provided here will serve as a ready reckoner for cable-stayed bridge designers and will help reduce the project cost and time by assessing the flutter susceptibility of bridges. Source

Srivastava A.,NIT Patna
ACM International Conference Proceeding Series

In this paper we evaluate a non-blind watermarking technique for colored digital image based on singular value decomposition (SVD) in the DWT (Discrete Wavelet Transformation) domain under different PSO variants. PSO is incorporated in the scheme to identify the most suited single value scaling factor to achieve high robustness and similarity ratio, existing PSO variants are compared and the best variant is then applied on the scheme. Experimental results are provided along with statistical analysis to exemplify that proposed scheme using best PSO variant is able to absorb various image processing attacks to a great extent and provide copyright protection. © 2015 ACM. Source

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