Time filter

Source Type

Kumar B.,Motilal Nehru National Institute of Technology | Kumar S.B.,Motilal Nehru National Institute of Technology | Chauhan D.S.,Feroze Gandhi Institute of Engineering and Technology
2015 38th International Conference on Telecommunications and Signal Processing, TSP 2015 | Year: 2015

This paper presents a spread-spectrum watermarking algorithm for embedding text watermark in to digital images in discrete wavelet transform (DWT) domain. The algorithm is applied for embedding text file represented in binary arrays using ASCII code into host digital radiological image for potential telemedicine applications. In order to enhance the robustness of text watermarks like patient identity code, BCH (Bose, Ray-Chaudhuri, Hocquenghem) error correcting code (ECC) is applied to the ASCII representation of the text watermark before embedding. Performance of the algorithm is analysed by varying the gain factor, subband decomposition levels, and length of watermark. Robustness of the scheme is tested against various attacks like compression, filtering, noise, sharpening, scaling and histogram equalization. Simulation results show that the proposed method achieves imperceptible watermarking for string watermarks. It is also observed that the use of BCH code improves the performance by reducing bit error rate (BER) performance. © 2015 IEEE.

Sharma R.,Feroze Gandhi Institute of Engineering and Technology | Dwivedi S.,Feroze Gandhi College | Sharma Y.,Feroze Gandhi College
International Journal of Hydrogen Energy | Year: 2015

Ternary intermetallic YPd3 is known to exhibit superior hydrogen storage capacity compared to pure palladium. To understand the characteristics of YPd3 on hydrogenation, the ground state electronic and dynamical properties were computed by two computational methods, the full potential linearized plane wave and projector augmented wave methods within the density functional theory. Hydrogen can be inserted in YPd3 at various octahedral sites, giving rise to model structures YPd3H and YPd3H4 which retain the L12 crystal structure. The calculated energy bands confirm the metallic nature of YPd3 and also exhibit greater dispersion of bands with increase in hydrogen content. Large variations in the optical constants such as transmittance is observed (by ∼40% in the violet region) with insertion of hydrogen, YPd3 may have thus have applications as a sensing device for monitoring hydrogen for using hydrogen safely. The electronic component γ obtained from the temperature dependent specific heats, is related to the density of states at the Fermi level which may be co-related to instability of hydrides. The modes at Γ-point in YPd3H and at X and M-points in YPd3H4 give rise to high peaks in the imaginary frequency regime which could drive the dynamical instabilities. From the formation energies and phonon modes it is found that the monohydride YPd3H is more stable, thus occupation of the octahedral sites at 2Y4Pd by hydrogen atoms results in greater dynamic instability in YPd3. © 2014 Hydrogen Energy Publications, LLC.

Mishra R.K.,Feroze Gandhi Institute of Engineering and Technology | Choudhury S.,University of Calcutta | Chaki N.,University of Calcutta
ACWR 2011 - Proceedings of the International Conference on Wireless Technologies for Humanitarian Relief | Year: 2011

Video-Medic services ease the availability of medical expertise even to the remotest geographical location where a stranded and isolated person requires an emergency medical attention. Facilitation of such services is being frequently recommended by both Government and Private agencies. The advent and deployment of 3G and above communication standards will play a major role in realizing the objective. The spread and accessibility of wireless and mobile networks may be utilized to make availability of the advices of medical expert, physically present at a state-of-art hospital to a remote patient. Similarly, the patient data or live footage on patients' current state may as well be sent to the doctor from a distant place. One of the most challenging aspects for applications deployed over 3G networks is to ensure assured QoS for data application in conjunction to live video transmission. However, these QoS provisioning need to be application-specific and at the same time, should not affect other services running at terminal equipment or mobile terminal (ME/TE). In this paper, agent based architecture has been proposed to ensure QoS for Video-Medic services. The proposed framework ensures that application specific optimizations for Video-Medic services do not deprive other concurrently executing applications over mobile terminal. © 2011 ACM.

Mishra R.K.,Feroze Gandhi Institute of Engineering and Technology | Chaki N.,University of Calcutta | Choudhury S.,University of Calcutta
Advances in Intelligent Systems and Computing | Year: 2015

Mobility of devices in cellular network induces several problems. This has drawn reasonable research attention in recent times. Designing appropriate Call Admission Control (CAC) mechanism and evaluating performances for such algorithms are among the crucial challenges in the domain. Such technologies continually evolve with the changing communication paradigms. In this paper, we have investigated various parameters that impact performance at home base station to facilitate seamless handover by an exhaustive simulation using George Mason University's Java-based MASON framework. The different parameters considered during simulation include handover threshold limits, user velocity, process prioritization, number of users in a cell, and redundancy for transceiver for better coverage. Through this exhaustive simulation, this paper aims to estimate the effect of factors influencing handoff as well as to test existing hypothesis about the handoff. The experimental results have disproved certain general conventions that are often assumed. © Springer India 2015.

Dwivedi S.,P.A. College | Sharma R.,Feroze Gandhi Institute of Engineering and Technology | Sharma Y.,P.A. College
Optical Materials | Year: 2014

The application of spinel oxides as transparent conducting oxides (TCOs) in optoelectronic devices as a substitute for ZnO is attracting attention in the recent years. Despite attractive photo-luminescence properties of zinc aluminate and zinc gallate, relatively little work has been done to interpret the optical response of spinel oxides on the basis of energy band structures. We present the electronic properties of ZnX2O4 (X = Al, Ga, In) calculated by the full potential linearized augmented plane wave method. Optical properties such as absorption coefficient and reflectivity are calculated and interpreted in terms of energy bands and density of states. Enhancement in optical properties was studied for Li and Mn ions doped in the ZnGa2O4 matrix. The main features in the experimentally observed photoluminescence spectra for doped and undoped ZnGa2O4 have been verified through the optical parameters. The transparence of spinel oxides to UV radiations is also clearly illustrated in the reflectivity vs. energy curves. At very small wavelengths the oxides may be used as reflective coating materials. Transport properties of the zinc spinel oxides have been investigated for the first time, and are found to have high Seebeck coefficients, high electrical conductivity and low thermal conductivity, with high value of figure of merit ZT ∼ 0.8. The study of vibrational and thermodynamic properties by the projector augmented wave method confirms the dynamic stability of the doped and undoped spinel oxides. Zinc spinel oxides are found to be p-type semiconductors with an optimum value of band gap ∼2-3 eV and appear to meet the conditions of low resistivity and high transparency (>80%) for state-of-art TCOs. © 2014 Elsevier B.V. All rights reserved.

Discover hidden collaborations