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.

A Pre-classification-Based Language Identification for Northeast Indian Languages Using Prosody and Spectral Features

Abstract: This paper is aimed at developing a two-stage language identification (LID) system for Northeast Indian languages. In the first stage, languages are pre-classified into tonal and non-tonal categories, and in the second stage, individual languages are identified from languages of the corresponding category. In this work, new parameters to model the prosodic characteristics of the speech signal have been proposed for pre-classification as well as individual language identification. Also, the effectiveness of spectral features, namely Mel-frequency cepstral coefficient (MFCC) and their combination with prosodic features, has been studied for pre-classification task. The usefulness of MFCC with their delta and acceleration coefficients in combination with prosodic features has been investigated for individual language identification. The performance of the system is analyzed for the features extracted of different analysis units, such as syllable, disyllable, word, and utterance. Comparative performance analysis of three different classifiers, namely artificial neural network (ANN), Gaussian mixture model–Universal background model (GMM–UBM), and i-vector based support vector machine (i-vector based SVM), has been made for pre-classification as well as individual language identification. A new database, NIT Silchar language database (NITS-LD), has been developed for seven NE Indian languages using All India Radio broadcast news. The experimental analysis suggests that the parameters proposed to represent the prosodic characteristics help to improve the performance of both the stages and show improvements over existing parameters by as much as 7.4%, 11.9%, and 9.1% for 30 s, 10 s, and 3 s test data, respectively, in the pre-classification stage. Of the baseline single-stage systems, GMM–UBM provides the highest accuracies of 80%, 76.8%, and 72% for 30 s, 10 s, and 3 s test data, respectively. In the proposed system, the combination of the ANN model in pre-classification stage and the GMM–UBM model in individual language identification stage provides the highest accuracies, and it shows the improvements over the baseline system by 7.2%, 7%, and 4.9% for 30 s, 10 s, and 3 s test data. For OGI-Multilingual (OGI-MLTS) database, improvements of 8.1%, 7.4%, and 5.7% for 30 s, 10 s, and 3 s test data, respectively, are observed over the baseline LID system.

Graph partitioning through a multi-objective evolutionary algorithm: a preliminary study

Abstract: The graph partitioning problem has numerous applications in various scientific fields. It usually involves the effective partitioning of a graph into a number of disjoint sub-graphs/zones, and hence becomes a combinatorial optimization problem whose worst case complexity is NP-complete. The inadequacies of exact methods, like linear and integer programming approaches, to handle large-size instances of the combinatorial problems have motivated heuristic techniques to these problems. In the present work, a multi-objective evolutionary algorithm (MOEA), a kind of heuristic techniques, is developed for partitioning a graph under multiple objectives and constraints. The developed MOEA, which is a modified form of NSGA-II, is applied to four randomly generated graphs for partitioning them by optimizing three common objectives under five general constraints. The applications show that the MOEA is successful, in most of the cases, in achieving the expected results by partitioning a graph into a variable number of zones.

An innovative framework for electrical energy storage system selection for remote area electrification with renewable energy system: Case of a remote village in India

Abstract: Electrical energy storage is a promising solution to overcome the intermittency and demand-supply mismatch problem in hybrid renewable energy systems. The objective of the present study is to prioritize ten electrical energy storage systems by using an innovative ranking framework, considering different criteria. Further, a techno-economic study of a hybrid renewable energy system is performed for rural area electrification, where the present selection strategy of the storage system is incorporated in the system design. Due to the conflicting nature of these criteria, a fuzzy assisted Technique for Order of Preference by Similarity to Ideal Solution method based framework is employed for its prioritization. The effect of variation of the weights on the criteria is also investigated through a sensitivity analysis. The framework is used to design an optimum hybrid renewable energy system for a remote village in India using the Hybrid Optimization Model for Electric Renewables tool. The results of the ranking show that pumped hydro storage, compressed air energy storage, and lead-acid batteries are the top three electrical energy storage systems that present more benefits for renewable energy integration for the present case. Moreover, adopting a storage system selection strategy can further reduce the cost of energy of the system. Therefore, the present framework provides a systematic procedure of storage system selection for renewable energy integration by considering different conflicting criteria for case-specific application.