Heritage Institute of Technology

About: Heritage Institute of Technology is a based out in . It is known for research contribution in the topics: Steganography & Support vector machine. The organization has 581 authors who have published 1045 publications receiving 8345 citations.

Linear array pattern synthesis using restriction in search space for evolutionary algorithms: A comparative study

Abstract: In this article, a comparative study between population based optimization methods with random and restricted search space definition applied in the pattern synthesis of linear antenna arrays is presented. Synthesis problem of reduced side lobe level and narrow beamwidth is considered. The design objective further considers the optimization of excitation amplitude and uniform inter element spacing using random and restricted search space definition by particle swarm optimization and differential evolution methods. As examples simulation of 12 and 21 elements have been considered. Effectiveness of the restriction in search space is proved through statistical and parametric analysis. Further comparison with published work has been carried out to prove the superiority of restricted search Particle Swarm Optimization.

Dependence of Negative Resistivity on Current Density and Junction Temperature for DDR IMPATT

Abstract: Negative resistivity of Si and Si0.9Ge0.1 DDR IMPATT diode are numerically computed using double iterative method and modified Runge-Kutta method and results are compared for identical input parameters. Simulation is based on simultaneous solution of Poisson's equation, continuity equation and carrier diffusion equation in addition with the effect of mobile space charge subject to the appropriate boundary conditions at the edges of depletion layer. Effect of junction temperature and current density on resistance is evaluated for optimum performance in CE mode. Peaks of the resistivity profile depend on temperature, bias current and frequency of operation. Results suggest that Si0.9Ge0.1 shows more negative resistance than the conventional one, and thus it may be considered as the suitable alternative choice for microwave source.

Chain Based Hierarchical Routing Protocol for Wireless Sensor Networks

Abstract: Wireless Sensor Networks (WSNs) are very crucial network system in present day for getting information from an unattendant environment. The small tiny sensor nodes can sense environment’s condition (temperature, pressure, humidity etc.) and send data to a particular location through wireless sensor networks. For collecting data from such an environment through these sensor nodes, there are different existing approaches in WSNs. LEACH[1] is one of them energy efficient cluster based routing protocol. In this paper we try to improve LEACH protocol by introducing a chain among the sensor nodes in each and every cluster as discussed in PEGASIS[2] protocol. The cluster heads get accumulated data or information from this chain and send it to its nearest base station (BS). Due to limited resources (energy, storage capacity, computing power etc) the lifetime of the sensor nodes are very restricted. LEACH protocol saves energy of the total network by using randomization for distributing the energy load among the sensor nodes and thus it enhances the lifespan of the network. But in the modified protocol, each sensor nodes except the cluster head sends sensed data to its nearest node, not to the cluster head like LEACH. As a result each node can preserve some energy and thus enhancing life span of the system. Moreover, since each node sends data to its nearest node, the modified approach can complete every round more quickly.

Designing information feedback for bidders in multi-item multi-unit combinatorial auctions

Abstract: Combinatorial auctions (CAs) promote allocative efficiency and are important market mechanisms for a wide variety of specialized domains where bidders are allowed to place bids on packages of items. However, the adoption of combinatorial auctions in real-life business scenarios has been fairly limited, perhaps because bidders find it difficult to construct their bids without extensive knowledge of the current state of the auction. In this paper, we develop decision support tools for bidders to provide information feedback at runtime for the general class of combinatorial auctions namely, online (continuous) multi-item multi-unit combinatorial auctions (MUCAs), an area that has witnessed a rapid growth of interest in recent years. In online MUCAs the number of packages may be large, and bidders need real time decision support to construct their bids, such as information on the ask prices of packages. The deadness level of a package serves as the ask price, and indicates the minimum bid on the package that keeps it in contention for inclusion in winning combinations in future. It has proved a challenge to find a satisfactory method for computing the deadness levels of packages in MUCAs. Here we present exact methods for determining package deadness levels in such auctions. Both the OR and the XOR formulations are considered. Experiments on simulated data as well as on live data show that the time and memory requirements are not excessive, so it appears possible to adopt the methods for the procurement and sale of commodities in B2B and B2C markets.

Optimization of Intensification of Freeze-Drying Rate of Banana: Combined Applications of IR Radiation and Cryogenic Freezing

Abstract: A programmed experimental study on infrared (IR) aided freeze-drying of cryogenically (LN2) frozen heat sensitive material viz. banana (Musa acuminata) rendered faster moisture separation rate compared to the conventionally frozen samples. Response surface methodology (RSM) could determine the simultaneous optimal freeze-drying conditions of 59.78°C IR temperature, 10 mm sample thickness, and 5 h drying time corresponding to the minimum moisture content of 4.11%, lowest final product temperature of 22.799°C, and maximum rehydration ratio of 1.72. Color difference, shrinkage, microstructure, pH, wettability, polysaccharide, and mineral contents of the cryogenically frozen freeze-dried banana at the optimal conditions have been determined coupled with Fourier Transform Infrared Spectroscopy (FTIR) and Carbon Hydrogen Nitrogen Sulfur (CHNS) analyses. Freeze-drying kinetics at optimal conditions have been evaluated and compared with literature published models and the “Handerson and Pabis” model was found to ...