National Institute of Technology, Silchar

About: National Institute of Technology, Silchar is a education organization based out in Silchar, Assam, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1934 authors who have published 4219 publications receiving 41149 citations. The organization is also known as: NIT Silchar.

The numerical analysis of combustion performance of a wedge shaped strut-based scramjet combustor

Abstract: The combustion performance of hydrogen fueled supersonic ramjet combustor has been computationally analysed. For the need of comparison, DLR Scramjet model of German Aerospace Center (DLR) has been taken into consideration. Off design analysis has also been conducted through the same model to see the appropriate changes. Ansys 14.0 fluent solver has been used to solve the two dimensional DLR Scramjet model with the help of Reynolds Averaged Navier-Stokes (RANS) equation. To have the reasonable accurateness of turbulent flow, RNG k-e two equation model has been chosen. The good agreement can be seen between present computation and the experiment data in open literature. Shock incident point follows the same pattern as previous experimentations and this can also be recognised in contour plots. To explore the variation behind the combustion performance by means of two selected parameters i.e. Mach number and temperature of incoming free stream air. This variation in the supersonic combustor is found helpful in terms of mixing length, shock wave behavioural strength, mixing efficiency and combustion efficiency. The changes in air speed lead to alter the incident location points of the shock waves. As the free stream air speed is getting higher, the appearance of fuel from the strut face became parallel in nature with air. Smallest mixing length of 26 mm is accomplished. Ignition delay between fuel entrainment and start of combustion did not take place in cases with Mach number 2.6, 2.8 and 3.0. However the superior combustion performance among all the selected cases is seen at the free stream air Mach number 3.0.

Impact of ferroelectric on the electrical characteristics of silicon–germanium based heterojunction Schottky barrier FET

Abstract: This work investigates the impact of ferroelectric gate oxide on high-k gate dielectric with low band gap Silicon Germanium ferroelectric Schottky barrier FET (SiGe Fe-SBFET), has been qualitatively simulated. The present research focuses on major improvement over the conventional device in terms of drain current and reduced subthreshold swing and analog performances. The proposed device has been analyzed in terms of numerous device electrostatic parameters such as electric field and energy band diagram using a ferroelectric material. A novel approach of SiGe-Fe-SBFET provides an effective technique helps to increase the performance in terms of on-current and off-state current of the device. The SiGe-Fe-SBFET also provides high Ion/Ioff ratio of 4.188 × 1012 and low Subthreshold swing of 67 mV/dec in comparison with germanium (Ge) and silicon (Si) material based ferroelectric SBFET. Apart from this, the increasing of tunneling width for the drive of carriers in the drain-channel junction, which results in a reduction of ambipolar conduction in off-state with gate drain underlap. Further, the analog performances of proposed and conventional device are evaluated such as transconductance, intrinsic gate delay, output conductance and cut-frequency which is dependent of parasitic gate capacitances are also investigated through a 2D Silvaco Atlas simulator.

Keypoints based enhanced multiple copy-move forgeries detection system using density-based spatial clustering of application with noise clustering algorithm

Abstract: In this study, the problem of detecting if an image has tampered is inquired; especially, the attention has been paid to the case in which the portion of an image is copied and then pasted onto another region to create a duplication or to hide some important portion of the image. The proposed copy-move forgery detection system is based on the scale-invariant feature transform (SIFT) features extraction and density-based clustering algorithm. The extracted SIFT features are matched using the generalised two nearest neighbours (2NN) procedure. Thereafter, the density-based clustering algorithm is utilised to improve the detection results. The proposed system is tested using MICC-F220, MICC-F2000 and MICC-F8multi datasets. Due to the generalised 2NN matching procedure, the proposed system is able to detect multiple forgeries present in the image. Experimental results show that the performance of the system is quite satisfactory in terms of computational time as well as detection accuracy.

An efficient scheduling scheme for MIMO-OFDM broadcast networks

Abstract: A new limited feedback user/antenna scheduling algorithm is proposed for multiple-input multiple-output orthogonal frequency division multiplexing broadcast networks. Feedback of channel state information at users to base station (BS) is inevitable for efficient spectrum utilization by performing the best possible scheduling of users/antennas. The feedback overhead increases with number of users and subcarriers. This enormous feedback information consumes useful bandwidth in uplink channel. Hence, in literature scheduling schemes with clustering of adjacent subcarriers (per-cluster scheduling) are proposed to reduce feedback overhead by considering channel condition of only the center subcarrier of cluster. According to proposed algorithm, channel conditions of all subcarriers are taken into consideration in a novel manner for efficient scheduling. The benefit of this scheme is attaining higher system throughput than the per-cluster scheduling scheme without incurring any additional feedback overhead. Moreover, this scheme achieves higher system throughput for large cluster size and more number of channel taps as compared to per-cluster scheduling scheme. Further throughput is improved by assigning previously unscheduled users randomly to transmit antennas which were not sending data packets to any users previously.