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: Control theory & Electric power system. The organization has 1934 authors who have published 4219 publications receiving 41149 citations. The organization is also known as: NIT Silchar.

Optimal design of unit hydrographs using probability distribution and genetic algorithms

Abstract: A nonlinear optimization model is developed to transmute a unit hydrograph into a probability distribution function (PDF). The objective function is to minimize the sum of the square of the deviation between predicted and actual direct runoff hydrograph of a watershed. The predicted runoff hydrograph is estimated by using a PDF. In a unit hydrograph, the depth of rainfall excess must be unity and the ordinates must be positive. Incorporation of a PDF ensures that the depth of rainfall excess for the unit hydrograph is unity, and the ordinates are also positive. Unit hydrograph ordinates are in terms of intensity of rainfall excess on a discharge per unit catchment area basis, the unit area thus representing the unit rainfall excess. The proposed method does not have any constraint. The nonlinear optimization formulation is solved using binary-coded genetic algorithms. The number of variables to be estimated by optimization is the same as the number of probability distribution parameters; gamma and log-normal probability distributions are used. The existing nonlinear programming model for obtaining optimal unit hydrograph has also been solved using genetic algorithms, where the constrained nonlinear optimization problem is converted to an unconstrained problem using penalty parameter approach. The results obtained are compared with those obtained by the earlier LP model and are fairly similar.

Enhancement of data storage capability in a bilayer oxide-based memristor for wearable electronic applications

Abstract: In this work, a ZnO/NiO bilayer architecture is introduced to fabricate transparent and flexible resistive random access memory (RRAM) device (Cu/ZnO/NiO/ITO) on polyethylene terephthalate (PET) substrate. The device exhibits excellent RS characteristics, such as forming free characteristic, low operating voltages, outstanding uniformity, long retention time (>104 s), high ON/OFF current ratio ~103, reliable multilevel cell (MLC) characteristics and excellent mechanical flexibility. The multilevel properties has been systematically evaluated by varying the compliance current and by tuning the stopping voltage, which shows that all the resistance state are distinguishable and remained stable without any considerable deprivation over 103 s. Intrinsic tailoring of RS mechanism has been well explained in the framework of electric field-induced formation and rupture of the reproducible Cu filaments in ZnO/NiO layer. Further, the metallic nature of conducting filament has further been confirmed by temperature-dependent variation of the high and low resistance states. Owing to the increasing demand of flexible electronics, the mechanical robustness of the proposed device has been examined by varying bending time and radius. The present RS device shows potential toward integration in many transparent, flexible and high-density storage devices, such as electronic skins and flexible displays.

Optimal size and location of distributed generations using Differential Evolution (DE)

Abstract: To improve the overall efficiency of power system, the performance of distribution system must be improved. This paper presents a new methodology using Differential Evolution (DE) for the placement of DG units in electrical distribution systems to reduce the power losses and to improve the voltage profile. Unlike the conventional evolutionary algorithms that depend on predefined probability distribution function for mutation process, differential evolution uses the differences of randomly sampled pairs of objective vectors for its mutation process. The Due to the increasing interest on renewable sources in recent times, the studies on integration of distributed generation to the power grid have rapidly increased. The distributed generation (DG) sources are added to the network mainly to reduce the power losses by supplying a net amount of power. In order to minimize the line losses of power systems, it is equally important to define the size and location of local generation. The suggested method is programmed under MATLAB software and is tested on IEEE 33-bus test system and the results are presented. The method is found to be effective and applicable for practical network.