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Protection and Control of Modern Power Systems 2023年第2期8卷 260-277页

作者： Neevatika verma Narendra Kumar Rajeev Kumar Department of Electrical Engineering Delhi Technological UniversityNew DelhiIndia Electrical Engineering Department Jamia Millia IslamiaNew DelhiIndia Electrical and Electronics Engineering Department KIET Group of InstitutionsGhaziabadIndia

This paper presents the issue of the Sub-synchronous resonance(SSR)phenomenon in a series compensated DFIG-based wind power plant and its alleviation using a Battery Energy Storage-based Damping Controller(BESSDCL).A supplementary damping signal is developed considering the angular speed deviation and is incorporated into the BESS control ***-area Measurement System data is used to determine the angular speed deviation.A lin-earized system model is developed to perform eigenvalue analysis,and to detect and examine unstable SSR *** variation of wind speed and three-phase fault are also taken into consideration to validate the robustness of the *** further verify the efficacy of the proposed damping controller,time-domain simulations are performed using MATLAB/*** application of the proposed BESSDCL stabilizes all the unstable system modes effectively at wind speeds of 7 m/s,9 m/s,and 11 m/s,and at 40%,50%,and 60%series compensation levels,as well three-phase fault conditions.

关键词： Battery energy storage system Damping controller Doubly-fed induction generator(DFIG) Series

Latitudinal fluctuation in global concentration of CO2 and CH4 from shortwave infrared spectral observation by GOSAT during COVID-19

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International Journal of Digital Earth 2021年第12期14卷 1882-1896页

作者： Laxmi Kant Sharma Rajani Kant verma Department of Environmental Science School of Earth SciencesCentral University of RajasthanAjmerIndia

Various countries have rapidly implemented strict actions to slow the blowout of *** events were dis-regarded,and anthropogenic activities such as industrial and transport systems were at a *** countries were on lockdown,including the largest emitters of carbon *** to these lockdowns,anthropogenic activities have been reduced and reported that air quality improves at a regional scale in many countries,including ***,the current study using Greenhouse Gases Observing Satellite(GOSAT/IBUKI)datasets to monitor the fluctuation of the average global concentration of dry mole fractions of atmospheric Methane(CH_(4))and Carbon Dioxide(CO_(2))during these pandemic lockdowns from January to June *** emphasize no significant reduction in the average concentration of dry mole fractions of atmospheric CH_(4) over the globe,but a minor reduction was observed in global CO_(2) *** average concentration of both gases compares at each ten-degree *** study reveals that,against the regional breakdowns,these short time lockdowns are not enough to control the concentration of these greenhouse gases at a larger scale,such as 10°latitude and globally,except for a minor reduction in CO_(2) concentration.

关键词： Lockdown pandemic air quality greenhouse gas methane carbon dioxide

Lumped parameter analytic modeling and behavioral simulation of a 3-DOF MEMS gyro-accelerometer

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Acta Mechanica Sinica 2015年第6期31卷 910-919页

作者： Payal verma Sandeep K.Arya Ram Gopal MEMS & Micro-sensors Group CSIR – Central Electronics Engineering Research Institute Department of Electronics & Communication Engineering Guru Jambheshwar University of Science & Technology

A new analytical model of a 3-degree-of-freedom （3-DOF） gyro-accelerometer system consisting of a 1-DOF drive and 2-DOF sense modes is presented. The model constructs lumped differential equations associated with each DOFof the system by vector analysis. The coupled differential equations thus established are solved analytically for their responses in both the time and frequency domains. Considering these frequency response equations, novel device design concepts are derived by forcing the sense phase to zero, which leads to a certain relationship between the structural frequencies, thereby causing minimization of the damping effect on the performance of the system. Furthermore, the feasibility of the present gyro-accelerometer structure is studied using a unique discriminatory scheme for the detection of both gyro action and linear acceleration at their events. This scheme combines the formulated settled transient solution of the gyro-accelerometer with the processes of synchronous demodulation and filtration, which leads to the in-phase and quadrature components of the system＇s output signal. These two components can be utilized in the detection of angular motion and linear acceleration. The obtained analytical results are validated by simulation in a MATLAB/Simulink environment, and it is found that the results are in excellent agreement with each other.

关键词： Microelectromechanical systems (MEMS) ·Multimeasurement system. Gyro-accelerometer Gyro-accelerometer model - Transient model

Continuous Mixed p-norm Control Scheme with Reweighted L_(0) norm Variable Step Size for Mitigating Power Quality Problems of Grid Coupled Solar PV Systems

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CSEE Journal of Power and Energy Systems 2023年第4期9卷 1394-1404页

作者： Pallavi verma Avdhesh Kumar Rachana Garg Priya Mahajan Delhi technological university DelhiDelhi 110085India.

In this paper,the performance of a two-stage three-phase grid coupled solar photovoltaic generating system(SPVGS)is analyzed by using a novel reweighted Lo norm variable step size continuous mixed p-norm(RLo-VSSCMPN)of a voltage source inverter(VSI)control *** efficacy of the system is determined by considering unbalanced grid voltage,DC offset,voltage sag and swell,unbalanced load and variations in solar ***-VSSCMPN is used for inverter control and it ex-tracts fundamental components of load current for generating the reference grid current with a faster convergence rate and lesser steady state *** the proposed control,harmonics in the grid current follows the IEEE-519 norm and the performance is also satisfactory under varying environmental/load *** power generated from SPvGS is transferred optimally using a DC-DC boost converter utilizing the incremental conductance(INC)maximum power point *** proposed system is simulated using MATLAB/Simulink 2018a and test results are verified experimentally using dSPACE1202 in the laboratory to ensure the validity of a novel proposed robust *** Terms-INC maximum power point tracker,power quality,reweighted LoVSSCMPN algorithm,solar PV generating system,total harmonic distortion,voltage source inverter.

关键词： INC maximum power point tracker power quality reweighted LoVSSCMPN algorithm solar PV generating system total harmonic distortion voltage source inverter.

Design of reaction conditions for the enhancement of microbial degradation of dyes in sequential cycles

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Journal of Environmental Sciences 2009年第12期21卷 1646-1651页

作者： Rashmi Sanghi Awantika Dixit Preeti verma Sadhna Puri Facility for Ecological and Analytical Testing 302 Southern Laboratories Institute of Technology The LNM Institute of Information Technology Jaipur Dayanand Girls College CSJM University

The present study evaluated the potential of white-rot fungal strain Coriolus versicolor to decolorize five structurally different dyes in sequential batch reactors under optimized conditions. The experiments were run continuously for seven cycles of 8 d each. High decolorizing activity was observed even during the repeated reuse of the fungus, especially when the old medium was replaced with fresh medium after every cycle. Biodegradation was the dominating factor as the fungus was able to produce the enzyme laccase mainly, to mineralize synthetic dyes. The nutrients and composition of the medium played important roles in sustaining the decolorisation potential of the fungus. Corncob was found be an easy and cheap substitute for carbon source for the fungus. Glucose consumption by the fungus was in accordance to its decolorisation activity and chemical oxygen demand （COD） reduction.

关键词： Coriolus versicolor decolorisation sequential batch reactor

Influence of rooftop telecommunication tower on set back-step back building resting on different ground slopes

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Earthquake Engineering and Engineering Vibration 2019年第2期18卷 351-362页

作者： Amit Thakur Deepankar Kumar Ashish Surender Kumar verma Civil Engineering Department Kurukshetra University Civil Engineering Department Maharaja Agrasen Institute of Technology Maharaja Agrasen University Civil Engineering Department Punjab Engineering College (Deemed to be University)

In the hilly region due to scarcity of the plain area, buildings like set back-step back are more often used and also as a big surge in the telecommunication industries, rooftop tower adaptation is very common story nowadays. In the present study an analogy has been drawn to find out the influence of the rooftop telecommunication tower on the setback-step back building resting on ground at 20° and 30° slopes. A dynamic analysis has been performed and compared on the 4 legged angled section telecommunication tower which is located on the roof top of set back-step back building by varying positions of tower with the existing host structure built up on ground slope of 20° and 30° in both directions(X and Y).

关键词： rooftop telecommunication tower set back-step back building response spectrum analysis steel, RC frame, earthquake SAP2000

Saddle Point Criteria in Nonsmooth Semi-Infinite Minimax Fractional Programming Problems

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Journal of Systems Science & Complexity 2018年第2期31卷 446-462页

作者： MISHRA S K SINGH Yadvendra verma R U Department of Mathematics Banaras Hindu University Varanasi-221005 India. Department of Mathematics Texas State University USA

This paper considers a nonsmooth semi-infinite minimax fractional programming problem（SIMFP） involving locally Lipschitz invex functions. The authors establish necessary optimality conditions for SIMFP. The authors establish the relationship between an optimal solution of SIMFP and saddle point of scalar Lagrange function for SIMFP. Further, the authors study saddle point criteria of a vector Lagrange function defined for SIMFP.

关键词： Generalized convexity Lagrange function nonsmooth programming problems saddlepoint semi-infinite minimax fractional programming problems.

Event-Triggered Sliding Mode Control for Trajectory Tracking of Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 307-314页

作者： Aquib Mustafa Narendra K.Dhar Nishchal K verma Department of Electrical Engineering Indian Institute of Technology KanpurUP 208016India

In this paper, an event-triggered sliding mode control approach for trajectory tracking problem of nonlinear input affine system with disturbance has been proposed. A second order robotic manipulator system has been modeled into a general nonlinear input affine system. Initially, the global asymptotic stability is ensured with conventional periodic sampling approach for reference trajectory tracking. Then the proposed approach of event-triggered sliding mode control is discussed which guarantees semi-global uniform ultimate boundedness. The proposed control approach guarantees non-accumulation of control updates ensuring lower bounds on inter-event triggering instants avoiding Zeno behavior in presence of the disturbance. The system shows better performance in terms of reduced control updates, ensures system stability which further guarantees optimization of resource usage and cost. The simulation results are provided for validation of proposed methodology for tracking problem by a robotic manipulator. The number of aperiodic control updates is found to be approximately 44% and 61% in the presence of constant and time-varying disturbances respectively.

关键词： Event-trigger inter execution time stability sliding mode control trajectory tracking

Pediatric hepatocellular carcinoma

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World Journal of Gastroenterology 2018年第35期24卷 3980-3999页

作者： Rajeev Khanna Sanjeev Kumar verma Department of Pediatric Hepatology Institute of Liver and Biliary SciencesNew Delhi 110070 India Department of Pediatrics King George Medical University

Pediatric hepatocellular carcinoma (HCC) is the second common malignant liver tumor in children after hepato-blastoma. It differs from the adult HCC in the etiological predisposition, biological behavior and lower frequency of cirrhosis. Perinatally acquired hepatitis-B virus, hepa-torenal tyrosinemia, progressive familial intrahepatic cho-lestasis, glycogen storage disease, Alagille's syndrome and congenital portosystemic shunts are important predis-posing factors. Majority of children (87%) are older than 5 years of age. Following mass immunization against hepatitis-B, there has been a drastic fall in the incidence of new cases of pediatric HCC in the Asia-Pacific region. Management is targeted on complete surgical removal either by resection or liver transplantation. There is a trend towards improving survival of children transplanted for HCC beyond Milan criteria. Chemotherapeutic regi-mens do not offer good results but may be helpful for down-staging of advanced HCC. Surveillance of children with chronic liver diseases with ultrasound and alpha-fetoprotein may be helpful in timely detection, intervention and overall improvement in outcome of HCC.

关键词： Hepatocellular carcinoma Children Riskfactors Outcome Liver transplantation

Development of Texture Mapping Approaches for Additively Manufacturable Surfaces

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 125-138页

作者： Bhupesh verma Omid Zarei Song Zhang Johannes Henrich Schleifenbaum Chair for Digital Additive Production RWTH Aachen University52074 AachenGermany

manufacturing(AM)technologies have been recognized for their capability to build complex components and hence have ofered more freedom to designers for a long *** ability to directly use a computer-aided design(CAD)model has allowed for fabricating and realizing complicated components,monolithic design,reducing the number of components in an assembly,decreasing time to market,and adding performance or comfort-enhancing *** of the features that can be introduced for boosting a component functionality using AM is the inclusion of surface texture on a given *** inclusion is usually a difcult task as creating a CAD model resolving fne details of a given texture is difcult even using commercial software *** paper develops a methodology to include texture directly on the CAD model of a target surface using a patch-based sampling texture synthesis algorithm,which can be manufactured using *** for the texture generation algorithm can be either a physical sample or an image with heightmap *** heightmap information from a physical sample can be obtained by 3D scanning the sample and using the information from the acquired point *** obtaining the required inputs,the patches are sampled for texture generation according to non-parametric estimation of the local conditional Markov random feld(MRF)density function,which helps avoid mismatched features across the patch *** generating the texture,a design constraint to ensure AM producibility is considered,which is essential when manufacturing a component using,e.g.,Fused Deposition Melting(FDM)or Laser Powder Bed Fusion(LPBF).The generated texture is then mapped onto the surface using the developed distance and angle preserving mapping *** implemented algorithms can be used to map the generated texture onto a mathematically defned *** paper maps the textures onto fat,curved,and sinusoidal surfaces for *** the texture m

关键词： Texture synthesis Design for additive manufacturing Image processing Textured surface generation Texture mapping