Showing papers by "National Institute of Technology, Meghalaya published in 2013"

Unsupervised Approach to Hindi Music Mood Classification

Abstract: We often choose to listen to a song that suits our mood at that instant because an intimate relationship presents between music and human emotions. Thus, the automatic methods are needed to classify music by moods that have gained a lot of momentum in the recent years. It helps in creating library, searching music and other related application. Several studies on Music Information Retrieval (MIR) have also been carried out in recent decades. In the present task, we have built an unsupervised classifier for Hindi music mood classification using different audio related features like rhythm, timber and intensity. The dataset used in our experiment is manually prepared by five annotators and is composed of 250 Hindi music clips of 30 seconds that consist of five mood clusters. The accuracy achieved for music mood classification on the above data is 48%.

Automatic generation control of multi-area system using two Degree of Freedom Fractional Order PID Controller: A preliminary study

Abstract: In this paper, Two-Degree-of-Freedom-Fractional Order-PID (2-DOF-FOPID) Controller is presented for automatic generation control of an interconnected three unequal area thermal system. Performances of different fractional order (FO) based classical controllers such as FOI, FOPI and FOPID are studied and compared with proposed 2-DOF-FOPID controller. Recently developed metaheuristic nature-inspired algorithm known as Firefly algorithm (FA) are used for the simultaneous optimization of several parameters of the controllers and speed regulation parameter (R) of the governor. Simulation results clearly reveal the superiority of the proposed 2-DOF-FOPID controller. Further, the performances of proposed controller are tested against higher degree of perturbation. It is observed that 2-DOF-FOPID controller perform far better than aforesaid FO controllers.

Ground leakage current elimination in a transformerless unipolar modulation based single phase grid-connected photovoltaic system

Abstract: Unipolar sinusoidal pulse width modulation (SPWM) full-bridge inverter poses advantages such as higher dc voltage utilization, smaller current ripple in the filter inductor, and higher processing efficiency. However, unipolar SPWM full-bridge inverter causes time varying common-mode voltage. The variable common-mode voltage excites leakage current through the parasitic capacitance between the PV array and the ground, which restricts its application in transformerless grid-connected photovoltaic (PV) inverter. In order to solve this problem, an optimized full-bridge topology is proposed in this paper. The topology uses an additional branch to be clamped the potential of the freewheeling path to the half of the input voltage in the freewheeling period, which guarantees no variable common-mode voltage in the unipolar SPWM full-bridge inverter. The proposed topology poses advantages such as higher efficiency, simple switching, and topological simplicity as compared to existing topologies. The proposed topology has been verified in MATLAB/Simulink environment with satisfactory results.

Development of an Automated Regional Coupled Atmosphere-Ocean Modeling System for Coastal Kalpakkam

Abstract: In this paper the development of an automated flux coupling mechanism applied to a Regional Coupled Atmosphere-Ocean Model (RCAOM) is reported. The coupler serves as an interface between two state-of-the-art models viz. Advanced Weather Research and Forecasting Model (WRF) and Princeton Ocean Model (POM). It has direct significance for ocean state forecasting studies such as prediction of sea-surface temperature (SST), surface circulations etc. RCAOM simulates local processes like upwelling along coastal Kalpakkam situated on the east coast of India and is also used to observe thermal recirculation at intake locations of cooling Jetties for the two nuclear power plants, Madras Atomic Power Plant (MAPS) and Prototype Fast Breeder Reactor (PFBR). The simulations reveal that the rise of temperature at intake locations of MAPS and PFBR occurs due to reversal wind system and exchange of heat fluxes and secondly upwelling is observed at the outfall location due to topographically induced effect in the absence o...

Reciprocal Unit Based on Vedic Mathematics for Signal Processing Applications

Abstract: Vedic mathematics, is an ancient methodology, has a unique mathematical computation technique based on 16 sutras (formulae). High speed reciprocal unit based on such ancient mathematics is reported in this paper. Implementation methodology was adopted through sahayaks (auxiliary fraction) taken from such ancient mathematics and prototype was designed for practical signal processing applications. On account of the Vedic formulae, reciprocal approximation of a numbers is generated in fewer steps compared to Newton-Raphson's iteration based implementation with appreciable error in accuracy (~0.09%), offer high speed operation. The functionality of the algorithm was checked, and performance parameters like propagation delay, dynamic switching power consumption were calculated through spice spectre using 90nm CMOS technology. The propagation delay of the resulting 5-digit reciprocal unit was only ~3.57uS and consumes ~30.8mW power. The implementation methodology offered substantial reduction of propagation delay, and dynamic switching power consumption from earlier reported Newton-Raphson (NR) based implementation.

Identifying Psychological Theme Words from Emotion Annotated Interviews

Abstract: Recent achievements in Natural Language Processing (NLP) and Psychology invoke the challenges to identify the insight of emotions. In the present study, we have identified different psychology related theme words while analyzing emotions on the interview data of ISEAR (International Survey of Emotion Antecedents and Reactions) research group. Primarily, we have developed a Graphical User Interface (GUI) to generate visual graphs for analyzing the impact of emotions with respect to different background, behavioral and physiological variables available in the ISEAR dataset. We have discussed some of the interesting results as observed from the generated visual graphs. On the other hand, different text clusters are identified from the interview statements by selecting individual as well as different combinations of the variables. Such textual clusters are used not only for retrieving the psychological theme words but also to classify the theme words into their respective emotion classes. In order to retrieve the psychological theme words from the text clusters, we have developed a rule based baseline system considering unigram based keyword spotting technique. The system has been evaluated based on a Top-n ranking strategy (where n=10, 20 or 30 most frequent theme words). Overall, the system achieves the average F-Scores of .42, .32, .36, .42, .35, .40 and .40 in identifying theme words with respect to Joy, Anger, Disgust, Fear, Guilt, Sadness and Shame emotion classes, respectively.

Design of a bio-inspired CMOS circuit realizing features of binocular rivalry between left and right eye

Abstract: This paper is an attempt to realize a unique feature of visual brain on CMOS circuit. There is a binocular rivalry phenomenon of visual brain in which, if two different images are shown to left and right eye then they compete for perceptual dominance such that one image become visible while the other get suppressed. Thus inspired from the concepts of neuromorphic and bio-inspired computing circuits, we would like to explain various features of binocular rivalry (BR) using Adaptive Winner Takes All (WTA) CMOS circuit. The application of this work lies in the fact that CMOS circuit can be implanted in the robot brain and hence opens a window in the area of artificial intelligence. The circuit is simulated using BSIM3 level 49 MOSFET models using T-Spice 0.35μm CMOS process. The key structure is an electronic synapse which is based around a floating-gate pFET. Thus the simulated results of the circuit depict two main features of binocular rivalry i.e., dominance and suppression of images and neural adaption. The circuit consumes 0.4mW total power, shows thermal stability of about 1.23μA/°C and occupies 25μm×20 μm chip area. Moreover a third and remarkable feature in BR is focused attention, which may considerably influence the binocular rivalry switching and can be attained using meditation. We would like to modify the circuit with additional, control of adaption at floating gate, circuitry to realize the later feature as well. The paper catered the later feature in future work.

Development of 1-ph hybrid active power filter with an efficient FPGA platform for power conditioning

Abstract: This paper deals with an advanced digital method to design the control algorithm for a single phase Hybrid Active Power Filter which shows a great promise in reducing harmonics and improvement in power quality. Major point of discussion in this paper includes principle of operation of Hybrid Active Power Filter (HAPF) with an efficient control algorithm for generation of the reference current. Generated reference currents are passed through the fixed band hysteresis current controller to produce switching signals for the Insulated Gate Bipolar Transistor (IGBTs) of the Hybrid Active Power Filter. Hybrid Active Power Filter is the combination of Passive Power Filter (PPF) and Active Power Filter (APF) responsible for producing opposite phase signals for compensation of the harmonics. The considered system is developed in Matlab/Simulink environment using Power system block set and the control algorithm is developed using Xilinx System Generator block set which automatically generates HDL code and can be downloaded to FPGA (Field programmable gate array) kit which is capable of producing faster switching signals for the IGBTs resulting a very good acceptable Total Harmonic Distortion (THD).

ASIC implementation of high speed processor for computing fast hartley transformation

Abstract: The improvement in speed and power for the computation of Discrete Hartley Transformation (DHT) using parallel addition technique is well established, but all the work have been reported in gate (FPGA) level. In this paper transistor level (ASIC) implementation technique for computation of high speed processor of prime length one dimensional Fast Hartley Transformation (FHT) based on MAC is reported for the first time. Equation formulation methodology for the transformation of such processors offered a technique of parallelism, also ensure substantial reduction of pre and post processing stages, owing towards high speed operation. The functionality of these circuits was checked and performance parameters like propagation delay, dynamic power consumptions were calculated through spice spectre using 45nm CMOS technology. The implementation methodology ensure substantial reduction of propagation delay in comparison with CORDIC, parallel adder (PA), distributed arithmetic and circular convolution (CC) based implementation which is most commonly used architecture, reported so far, for DHT processors. The propagation delay of the resulting 16 point FHT processor is only ~7.68μs while the power consumption of the same was ~90.5mW only. Almost 50% improvement in speed from earlier reported FHT processors, e.g. CORDIC, PA and CC based implementation methodology, has been achieved.

Heterobimetallic Ir—Sn Catalysis: Aza‐Friedel—Crafts Reaction of N‐Sulfonyl Aldimines.

Abstract: The authors present a convenient way for the formation of di- and triarylmethanes and heteroarylmethanes.