Shishir Kumar

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In this paper, a novel image watermarking scheme has been presented, which is based on Divisive Normalization Transform, Discrete Wavelet Transform and Singular Value Decomposition. Through this paper an attempt has been made to solve the problem of statically and perceptually redundant wavelet coefficients, used during watermarking with the help of(More)
A large magnetoresistance (MR) effect of few-layers graphene between two non-magnetic metal electrodes with current perpendicular to graphene plane is studied. A non-saturation and anisotropic MR with the value over 60% at 14 T is observed in a two-layer graphene stack at room temperature. The resistance of the device is only tens of ohms, having the(More)
It is well known that the images, often used in variety of computer applications, are difficult to store and transmit. One possible solution to overcome this problem is to use a data compression technique where an image is viewed as a matrix and then the operations are performed on the matrix. In this paper, image compression is achieved by using Singular(More)
In this paper, a tailored blended image adaptive watermarking scheme has been presented, which is based on DWT and SVD. Through this paper an attempt has been made to solve the problem of false positive while maintaining the robustness and imperceptibility with the help of principal component and perceptual tuning of the image. Perceptual tuning is a(More)
Graphene layers have been transferred directly on to paper without any intermediate layers to yield G-paper. Resistive gas sensors have been fabricated using strips of G-paper. These sensors achieved a remarkable lower limit of detection of ∼300 parts per trillion (ppt) for NO2, which is comparable to or better than those from other paper-based sensors.(More)
This communication describes the electrochemical properties of thin pyrolytic carbon (PyC) films created using a reliable, non-catalytic chemical vapour deposition (CVD) process. After deposition, the electron transfer characteristics of the films are optimised using a simple oxygen plasma treatment. The redox probes 3 /2 3 6 Ru(NH ) + + , 3 /4 6 Fe(CN) − −(More)
A gas phase controlled graphene synthesis resembling a CVD process that does not critically depend on cooling rates is reported. The controllable catalytic CVD permits high quality large-area graphene formation with deft control over the thickness from monolayers to thick graphitic structures at temperatures as low as 750 degrees C.
Survival of the Leishmania parasite within monocytes hinges on its ability to effectively nullify their microbicidal effector mechanisms. Accordingly, this study aimed to delineate this biological niche in patients with visceral leishmaniasis (VL). In monocytes, the redox status, antigen presenting capacity, expression of Toll-like receptors (TLRs),(More)
A two-timescale simulation-based actor-critic algorithm for solution of infinite horizon Markov decision processes with finite state and compact action spaces under the discounted cost criterion is proposed. The algorithmdoes gradient search on the slower timescale in the space of deterministic policies and uses simultaneous perturbation stochastic(More)