National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Computer science. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Power quality enrichment using enhanced adaptive control-detuned-LC proposal in voltage source control conquered distributed generation with hardware implementation:

Abstract: This paper presents the collective operation and comparative assessment of artificial neural network (ANN)-based adaptive controller with detuned-inductor capacitor (LC) filter facility in grid-tie...

An Analytical and Experimental Study of Nonlinear Intermodulation in Delaminated Composite Plate

Abstract: Nowadays, nonlinear wave spectroscopy (NLWS) technique is a very famous and modern technique for finding micro-cracks in any structural materials. One of the NLWS techniques is based on local defect resonance (LDR) frequency of defects, which is developed recently for detecting the delamination and micro-cracks in composite materials. The present study discusses LDR-based detection of delamination in glass fiber reinforced plastic (GFRP) plate with single delamination, analytically as well as experimentally. Two different exciting frequencies are provided to the GFRP plate surface for generating the nonlinear intermodulation peaks at the damage location. One of the exciting frequencies is considered as sub-harmonic or superharmonic of LDR frequency while the second excitation is taken as a single periodic frequency (SPF). Subsequently, fast Fourier transform (FFT) of the receiver signal is performed for obtaining local defect resonance intermodulation (LDRI) and single periodic frequency intermodulation (SPFI) peaks. Finally, the analytical and experimental results are compared and are found to be in good agreement with each other.

Quasi-straightness based features for off-line verification of signatures

Abstract: Person identification from their signatures or verifying the genuineness of official documents like bank cheques, certificates, contract forms, bonds etc. still remains a challenging task when accuracy and computation time are concerned. In this paper, a novel set of features based on the distribution of the quasi-straight line segments has been presented for off-line signature verification. For the detection of the set of quasi-straight line segments, defining the signature boundary, 8-N chain codes are used. Twelve different classes of quasi-straight line segments are obtained depending upon the orientations of the line segments. Subsequently, the feature set is obtained from those twelve classes. Support Vector Machine (SVM) classifier has been used by us for verification. Results on standard signature databases like CEDAR (Center of Excellence for Document Analysis and Recognition) database and GPDS-100 (Grupo de Procesado Digital de la Senal) are shown to adjudge the fitness of the proposed method.

Power quality analysis in a grid connected PV system employing a hybrid technique based on Fractional Wavelet Transform

Abstract: In this paper, a novel detection technique using Fractional Wavelet Transform (FRWT) is applied for monitoring three-phase grid connected PV generation system. The idea behind this protection scheme is based on combined features derived from Discrete Fractional Fourier Transform (DFRFT) and Discrete Wavelet Transform (DWT) techniques, which provides more actual time-frequency information. In this study, DFRFT is applied for the fast recognition of a transformed signal via fractional rotation in time-frequency plane and DWT is applied for detecting power disruption in the system more accurately. The effectiveness of applied hybrid technique is also compared with Wavelet Transform (WT) by simulating the system in MATLAB/SIMULINK environment. The simulated results demonstrate the feasibility and effectiveness of the proposed detection strategy under noisy situation and also in the existence of harmonics.

Time delay compensation by estimating speed error of a PMDC motor using backward arc length approach

Abstract: In high precision control of DC drives, real-time error calculation is the most vital controlling parameter. Due to the time delay of the control circuit, mostly controlling action has been initiated based on the past error that may hamper the precision of the controller. In this regards, future error has to be estimated to initiate the controlling action based on real-time error. But due to the presence of uncertainty in load and also the presence of mechanical inertia in the system, it is difficult to estimate the future speed error based on the Permanent Magnet Direct Current (PMDC) motor system equation. In this paper, the speed error estimation of PMDC motor has been incorporated based on backward arc length of error graph itself. The proposed error estimation approach applied to PMDC motor speed error tracking will overcome the effect of processing time delay of the controller. This proposed speed error tracking method pointing towards the time delay control of PMDC motor. This technique will help to compensate the effect of processing delay time of used controller.