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Geoscience Frontiers 2018年第2期9卷 335-354页

作者： santanu kumar bhowmik Somnath Dasgupta Sudipta Baruah Deepika Kalita Department of Geology and Geophysics Indian Institute of Technology Kharagpur Department of Geography Faculty of Natural SciencesJamia Millia Islamia

In this study, we investigate the possible record of a Late Mesoproterozoic paired metamorphic belt in the Aravalli-Delhi Mobile Belt(ADMB), NW India using a suite of supracrustal and metaigneous granulites from the Pilwa-Chinwali granulite terrain at the north-western margin of the ADMB. Using metamorphic reaction textures, mineral chemistry, metamorphic reaction history, geothermobarometric computations and electron microprobe dating of monazite in 5 samples of pelitic granulite, leptynite gneiss, enderbite and charnockite, we have deduced a medium-pressure granulite facies metamorphism(P between 4.9 and 6.8 kbar, T> 760-815℃) along a heating-cooling, counterclockwise P-T path between 1.09 and 1.01 Ga. When collated with published metamorphic and chronological constraints and geological settings of the adjoining crustal domains of the ADMB, these findings provide new insights into the developments of two tectonic domains of contrasting thermal gradients at ca. 1.0 Ga, consistent with metamorphic transformations in tectonically thickened middle-lower crustal sections during continental collision to continental subduction and in the root zones of spatially adjacent island arc, as part of the Rodinia supercontinent assembly event.

关键词： ADMB Granulites CCW-P-T path Monazite chemical dating ca. 1.0 Ga metamorphism Paired metamorphic belt

Identification and modelling of applicable wear conditions for stir cast Al-composite

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Friction 2020年第5期8卷 847-873页

作者： santanu SARDAR santanu kumar KARMAKAR Debdulal DAS Department of Mechanical Engineering Indian Institute of Engineering Science and TechnologyHowrah 711103India Department of Metallurgy and Materials Engineering Indian Institute of Engineering Science and TechnologyHowrah 711103India

A comprehensive study of the tribological performance of the Al-Zn-Mg-Cu/Al2O3 composite and its matrix alloy is presented in this paper, with a specific emphasis to identify and model the applicable wear conditions where the composite provides a minimum of 50% reduction in wear rate and 25% lowering of the friction coefficient. Two-body abrasion experiments following Taguchi L27 orthogonal design have been performed separately on alloy and composite materials, both prepared by the stir casting method. The influence of crucial control factors including silicon carbide (SiC) abrasive size, load, sliding distance, and velocity on the percentage variations of wear rates and friction coefficients between alloy and composite have been studied using the analysis of variance technique and full quadratic regression method. The dominant control factors are identified as abrasive size, load, and the interaction between abrasive size and load. This has been verified by establishing the influence of abrasive size and load on variations of wear mechanisms like microcutting, microploughing, and delamination, identified by means of in-depth characterization of worn surfaces and generated debris for both alloy and composite. The selection of applicable tribological condition for the composite has been accomplished by adopting the multi-response optimization technique based on combined desirability approach to obtain concurrent optimization of the percentage variations of wear rates and friction coefficients. Predictive models correlating the superiority of tribological performance of composite with abrasion conditions have been developed, and these are found to be accurate (errors <10%), as determined by confirmatory experiment.

关键词： aluminum matrix composite tribology design of experiment Taguchi multi-response optimization abrasion mechanism

Position Control of a Flexible Manipulator Using a New Nonlinear Self-Tuning PID Controller

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 136-149页

作者： santanu kumar Pradhan Bidyadhar Subudhi School of Electrical Sciences National Institute of Science and Technology BerhampurOdisha 761008India School of Electrical Sciences Indian Institute of TechnologyFarmagudiGoa 403401India

In this paper, a new nonlinear self-tuning PID controller(NSPIDC) is proposed to control the joint position and link deflection of a flexible-link manipulator(FLM) while it is subjected to carry different payloads. Since, payload is a critical parameter of the FLM whose variation greatly influences the controller performance. The proposed controller guarantees stability under change in payload by attenuating the non-modeled higher order dynamics using a new nonlinear autoregressive moving average with exogenous-input(NARMAX) model of the FLM. The parameters of the FLM are identified on-line using recursive least square(RLS) algorithm and using minimum variance control(MVC) laws the control parameters are updated in real-time. This proposed NSPID controller has been implemented in real-time on an experimental set-up. The joint tracking and link deflection performances of the proposed adaptive controller are compared with that of a popular direct adaptive controller(DAC). From the obtained results, it is confirmed that the proposed controller exhibits improved performance over the DAC both in terms of accurate position tracking and quick damping of link deflections when subjected to variable payloads.

关键词： Flexible-link manipulator position control self-tuning control NARMAX trajectory tracking

Development and Characterization of Al_2O_3 Dispersed Al/Mg/Cu/Ti Matrix Composite

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Journal of Materials Science & Technology 2013年第11期29卷 1085-1090页

作者： Sumit Chabri Subhranshu Chatterjee santanu Pattanayak Himel Chakraborty Nandagopal bhowmik Arijit Sinha Department of Metallurgy and Materials Engineering Bengal Engineering and Science University School of Materials Science and Engineering Bengal Engineering and Science University

The effect of dispersion with different weight fractions of Al2O3 particles in metallic matrices （AI/Mg/Ti/Cu） fabricated by powder metallurgy was investigated. In the case of 15 wt% Al2O3 reinforced composites, peak hardness was attained which subsequently decreased with increasing the content of Al2O3. A correlation between the microhardness and nanomechanical properties at submicron scale was examined for all the composites. Specific strength and specific modulus were measured in order to figure out the performance of the composites.

关键词： Metal matrix composites Powder metallurgy Hardening Coarsening Hardness Nanoindentation

Software design pattern mining using classification-based techniques

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Frontiers of Computer Science 2018年第5期12卷 908-922页

作者： Ashish kumar DWIVEDI Anand TIRKEY santanu kumar RATH Department of Computer Science and Engineering National Institute of Technology Rourkela 769008 India

Design patterns are often used in the development of object-oriented software. It offers reusable abstract information that is helpful in solving recurring design problems. Detecting design patterns is beneficial to the comprehension and maintenance of object-oriented software systems. Several pattern detection techniques based on static analysis often encounter problems when detecting design patterns for identical structures of patterns. In this study, we attempt to detect software design patterns by using software metrics and classification-based techniques. Our study is conducted in two phases： creation of metrics-oriented dataset and detection of software design patterns. The datasets are prepared by using software metrics for the learning of classifiers. Then, pattern detection is performed by using classification-based techniques. To evaluate the proposed method, experiments are conducted using three open source software programs, JHotDraw, QuickUML, and JUnit, and the results are analyzed.

关键词： design patterns design pattern mining machinelearning techniques object-oriented metrics

High-throughput discovery of high Curie point two-dimensional ferromagnetic materials

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npj Computational Materials 2020年第1期6卷 1381-1389页

作者： Arnab Kabiraj Mayank kumar santanu Mahapatra Nano-Scale Device Research Laboratory Department of Electronic Systems EngineeringIndian Institute of Science(IISc)BangaloreBangalore 560012India

Databases for two-dimensional materials host numerous ferromagnetic materials without the vital information of Curie temperature since its calculation involves a manually intensive complex *** this work,we develop a fully automated,hardwareaccelerated,dynamic-translation based computer code,which performs first principles-based computations followed by Heisenberg model-based Monte Carlo simulations to estimate the Curie temperature from the crystal *** employ this code to conduct a high-throughput scan of 786 materials from a database to discover 26 materials with a Curie point beyond 400 *** rapid data mining,we further use these results to develop an end-to-end machine learning model with generalized chemical features through an exhaustive search of the model space as well as the *** discover a few more high Curie point materials from different sources using this data-driven *** material informatics,which agrees well with recent experiments,is expected to foster practical applications of two-dimensional magnetism.

关键词： structure process ferromagnetic

Geochemical signatures of potassium metasomatism in anthracite from the Himalayan fold‑thrust belts of Sikkim,India

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International Journal of Coal Science & Technology 2022年第2期9卷 48-69页

作者： santanu Ghosh Anwita Ojha Atul kumar Varma Coal Geology and Organic Petrology Laboratory Department of Applied GeologyIndian Institute of Technology(Indian School of Mines)DhanbadJharkhand 826004India Department of Earth Sciences Indian Institute of Technology BombayPowaiMumbaiMaharashtra 400076India

The present study focuses on the inorganic geochemical features of the bituminous coal samples from the Raniganj and the Jharia Basins,as well as the anthracite samples from the Himalayan fold-thrust belts of Sikkim,*** SiO_(2)content(48.05 wt%to 65.09 wt%and 35.92 wt%to 50.11 wt%in the bituminous and anthracite samples,respectively)and the ratio of Al_(2)O_(3)/TiO_(2)(6.97 to 17.03 in the bituminous coal samples and 10.34 to 20.07 in the anthracite samples)reveal the intermediate igneous source rock composition of the *** ratio of the K_(2)O/Al_(2)O_(3)in the ash yield of the bituminous coal samples(0.03 to 0.09)may suggest the presence of kaolinite mixed with montmorillonite,while its range in the ash yield of the anthracite samples(0.16 to 0.27)may imply the presence of illite mixed with *** chemical index of alteration values may suggest the moderate to strong chemical weathering of the source rock under sub-humid to humid climatic *** plot of the bituminous coal samples in the A–CN–K diagram depicts the traditional weathering trend of parent rocks,but the anthracite samples plot near the illite feld and are a bit ofset from the weathering *** may imply the plausible infuences of the potassium-metasomatism at post coalifcation stages,which is further supported by high K_(2)O/Na_(2)O ratio(29.88–80.13).The Fourier transform infrared spectra further reveal the hydroxyl stretching intensity of illite in the anthracite samples substantiating the efect of the epigenetic *** decrease in total kaolinite intensity/compound intensity of quartz and feldspar may provide additional evidence towards this epigenetic event.

关键词： Himalayan fold-thrust belts Anthracite Potassium metasomatism Kaolinite to quartz-feldspar intensity ratio Montmorillonite stretching and bending intensities Illite-stretching frequency

An effective fault prediction model developed using an extreme learning machine with various kernel methods

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Frontiers of Information Technology & Electronic Engineering 2018年第7期19卷 864-888页

作者： Lov kumar Anand TIRKEY santanu-Ku.RATH Department of Computer Science and Engineering National Institute of Technology Rourkela

System analysts often use software fault prediction models to identify fault-prone modules during the design phase of the software development life cycle. The models help predict faulty modules based on the software metrics that are input to the models. In this study, we consider 20 types of metrics to develop a model using an extreme learning machine associated with various kernel methods. We evaluate the effectiveness of the mode using a proposed framework based on the cost and efficiency in the testing phases. The evaluation process is carried out by considering case studies for 30 object-oriented software systems. Experimental results demonstrate that the application of a fault prediction model is suitable for projects with the percentage of faulty classes below a certain threshold, which depends on the efficiency of fault identification(low: 47.28%; median: 39.24%; high: 25.72%). We consider nine feature selection techniques to remove the irrelevant metrics and to select the best set of source code metrics for fault prediction.

关键词： CK metrics Cost analysis Extreme learning machine Feature selection techniques Object-oriented software

Load shedding strategy coordinated with storage device and D-STATCOM to enhance the microgrid stability

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Protection and Control of Modern Power Systems 2019年第1期4卷 262-280页

作者： Sheetal Chandak Pritam bhowmik Pravat kumar Rout Electrical Engineering Department Siksha‘O’Anusandhan UniversityBhubaneswar751030India Electrical and Electronics Engineering Department Siksha‘O’Anusandhan UniversityBhubaneswar751030India

Recently microgrids have drawn a potential attraction by fulfilling the environmental demands and the increasing energy demands of the end-users. It is necessary to focus on various protection and control aspects of a microgrid. During the transition between the grid-following and grid-forming modes, the voltage and the frequency instability due to the power mismatch condition becomes the major point of concern. Therefore, the paper executes a frequency-active power and voltage-reactive power drooping control strategy for the precise power-sharing among the distributed power generators. Furthermore, to handle the power deficit scenarios and to maintain the system stability, a system independent and priority-based adaptive three-stage load shedding strategy is proposed. The sensitivity of the strategy depends on the system inertia and is computed according to the varying absolute rate-of-change-of-frequency. The strategy incorporates the operation of battery storage system and distributed static compensator (D-STATCOM) in the microgrid, to provide a reliable power supply to the customers for a considerable time instead of a sudden load shedding. The effectiveness of the proposed strategies is investigated on a scaled-down modified IEEE 13-bus microgrid system on the podium of MATLAB 2015b through the time-domain simulation.

关键词： Microgrid Power-sharing Load shedding High inertia distributed generators Inertia-less distributed generators Battery storage system D-STATCOM

Reliability and efficiency enhancement of a radial distribution system through value-based auto-recloser placement and network remodelling

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Protection and Control of Modern Power Systems 2023年第1期8卷 1-14页

作者： Bratati Ghosh Ajoy kumar Chakraborty Arup Ratan bhowmik Department of Electrical Engineering National Institute of Technology AgartalaJiraniaTripura 799046India

The electric distribution system(EDS)is prone to faults leading to power *** present energy market demands that electricity utilities invest more in different measures to improve the performance of the *** approach proposed here details a composite dual-phased methodology to improve the reliability and efficiency of the power delivered by the *** the first phase,the optimal allocation of auto-reclosers(AR)is undertaken by employing a newly formulated *** determination of the total number and location for AR placement is based on the economic analysis of two factors,i.e.,AR investment-maintenance cost and total benefit earned in terms of reliability improvement due to AR *** analysis also takes into account the impact of power outages on different load types,the load growth rate,and the inflation ***,to enhance the efficiency of the AR-incorpo-rated EDS,the technique of Radial Distribution System Remodelling is employed in the second *** method searches for a radial configuration that delivers power at minimum line *** phases comprising complex combinatorial operations are aided by a fresh hybrid of the Sine Cosine Algorithm,Krill Herd Algorithm,and a genetic operator of Differential *** results obtained from its application on the IEEE 69-bus distribution test system prove the credibility of the suggested formulation.

关键词： Auto-recloser placement Load flow Metaheuristic optimization algorithm Power loss minimization Reconfiguration Reliability assessment