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Chinese Annals of Mathematics,Series B 2012年第6期33卷 831-840页

作者： pankaj kumar SRIVASTAVA Manoj kumar Department of Mathematics Jaypee Institute of Information Technology Department of Mathematics Motilal Nehru National Institute of Technology

A numerical algorithm is developed for the approximation of the solution to certain boundary value problems involving the third-order ordinary differential equation associated with draining and coating flows. The authors show that the approximate so- lutions obtained by the numerical algorithm developed by using uonpolynomial quintic spline functions ave better than those produced by other spline and domain decomposition methods. The algorithm is tested on two problems associated with draining and coating flows to demonstrate the practical usefulness of the approach.

关键词： Third-order boundary value problem Spline functions Nonpolynomial quartic spline Nonpolynomial quintic spline Draining and coating flows

Flow past a bluff body subjected to lower subcritical Reynolds number

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Journal of Ocean Engineering and Science 2020年第2期5卷 173-179页

作者： pankaj kumar Santosh kumar Singh Department of Mechanical Engineering SRM Institute of Science and TechnologyKattankulathur 603203India

The paper aimed to study the flow structure at the wake of the bluff body with altered blockage ratio(BR)keeping the fixed aspect ratio(AR).The study was conducted by a finite volume technique using commercial software *** CFD analysis of the bluff body is mainly subjected to the lower subcritical Reynolds number range(5000 to 15,000)along with blockage ratio as an important *** flow parameters such as drag coefficient,pressure,and kinetic energy variations are analyzed here for the Reynolds number(Re)and *** was observed that at fixed Re,t he drag coefficient(C_(D))increases with an increase in the BR while decrease with increasing Re for a fixed value of BR.

关键词： Blockage ratio Bluff body Drag coefficient Reynolds number

Particle Swarm Optimization Based Support Vector Regression for Blind Image Restoration

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Journal of Computer Science & Technology 2012年第5期27卷 989-995页

作者： Ratnakar Dash pankaj kumar Sa Banshidhar Majhi Computer Science and Engineering Department National Institute of Technology RourkelaRourkela 769008India

This paper presents a swarm intelligence based parameter optimization of the support vector machine （SVM） for blind image restoration. In this work, SVM is used to solve a regression problem. Support vector regression （SVR） has been utilized to obtain a true mapping of images from the observed noisy blurred images. The parameters of SVR are optimized through particle swarm optimization （PSO） technique. The restoration error function has been utilized as the fitness function for PSO. The suggested scheme tries to adapt the SVM parameters depending on the type of blur and noise strength and the experimental results validate its effectiveness. The results show that the parameter optimization of the SVR model gives better performance than conventional SVR model as well as other competent schemes for blind image restoration.

关键词： image restoration support vector regression particle swarm optimization

Analysis of Dielectric and Electro-optic Responses of Nanomaterials Doped Ferroelectric Liquid Crystal Mixture

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Journal of Materials Science & Technology 2011年第12期27卷 1094-1098页

作者： Neeraj pankaj kumar K.K. Raina Material Research Laboratory School of Physics and Materials Science Thapar University Patiala 147004 India Department of BIN Fusion Technology Chonbuk National University Jeonju Jeonbuk 561-756 Korea Department of Applied Science Chitkara University Jansala Rajpura Patiala-140401 Punjab India

Dielectric and rotational viscosity measurements of a multi-component ferroelectric liquid crystal mixture were performed by adding a small concentration （0.01 wt%） of silica and multi walled carbon nanotubes （MWCNTs）. Liquid crystals turn out to be outstanding hosts for nanomaterials. A remarkable increase in the rotational viscosity was noticed in CNT doped system as compared to silica doped same liquid crystal system. Comparison of dielectric studies shows higher value of permittivity and dielectric losses for silica-doped sample than those of CNT doped sample. The results have been interpreted both experimentally and theoretically.

关键词： Ferroelectric liquid crystals Silica nanoparticles Carbon nanotubes Dielectricpermittivity Rotational viscosity

Texture evaluation in AZ31/AZ31 multilayer and AZ31/AA5068 laminar composite during accumulative roll bonding

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Defence Technology（防务技术） 2020年第3期16卷 514-519页

作者： pankaj kumar Aviral Madhup Prasad RKalvala Satyam Suwas Chemical and Materials Engineering University of NevadaRenoNV89557USA Materials Engineering Indian Institute of ScienceBangalore560012India

This article presents the texture development of magnesium AZ31 alloy in the accumulative roll bonded(ARB) AZ31/AZ31 multilayer and AZ31/AA5086 laminate *** comparative study demonstrates that the texture evolution in AZ31 in a multilayer system is strongly influenced by the interfaces.A typical basal texture of AZ31 has been observed in AZ31/AZ31 multilayer with texture intensity increased with the rolling *** of AZ31/AA5086 interface in the laminate composite leads to a tilted basal texture along the rolling direction(RD) in AZ31 *** texture intensity of composite increased initially with rolling reduction and weakened at the higher rolling *** of texture in AZ31 during the laminate processing at higher strain has been attributed to the development of wavy interfaces in AZ31/AA5086 laminate.

关键词： Accumulative roll bonding Defence application AZ31 alloy Texture Composite Laminates

Impact of land cover change on land surface temperature: A case study of Spiti Valley

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Journal of Mountain Science 2018年第8期15卷 1658-1670页

作者： kumar pankaj HUSAIN Arif SINGH Ram Babu kumar Manish Department of Geography Delhi School of Economics University of Delhi Department of Geography Kalindi College University of Delhi

Land surface temperature(LST) is the skin temperature of the earth surface. LST depends on the amount of sunlight received by any geographical area. Apart from sun light, LST is also affected by the land cover, which leads to change in land surface temperature. Impact of land cover change(LCC) on LST has been assessed using Landsat TM5, Landsat 8 TIRS/OLI and Digital Elevation Model(ASTER) for Spiti Valley, Himachal Pradesh, India. In the present study, Spiti valley was divided into three altitudinal zones to check the pattern of changing land cover along different altitudes and LST was calculated for all the four land cover categories extracted from remote sensing data for the years of 1990 and 2015. Matrix table was used as a technique to evaluate the land cover change between two different years. Matrix table shows that as a whole, about 2,151,647 ha(30%) area of Spiti valley experienced change in land cover in the last 25 years. The result also shows vegetation and water bodies increased by 107,560.2 ha(605.87%) and 45 ha(0.98%), respectively. Snow cover and barren land decreased by 19,016.5 ha(23.92%) and 88,589(14.14%), during the study period. A significant increase has been noticed in vegetation amongst all land cover types. Minimum, maximum and mean LST for three altitudinal zones have been calculated. The mean LST recorded was 11℃ in 1990 but it rose by 2℃ and reached to 13℃ in 2015. Changes in LST were obtained for each land cover categories. The mean temperature of different land cover types was calculated by averaging value of all pixels of a given land cover types. The mean LST of vegetation, barren land, snow cover and water body increased by 6℃, 9℃, 1℃, and 7℃, respectively. Further, relationships between LST, Normalized Difference Snow Index(NDSI), and Normalised Difference Vegetation Index(NDVI) were established using Linear Regression.

关键词： Land surface temperature Land cover change Normalised difference snow index Normalised Difference Vegetation Index DEM Remote Sensing GIS Linear Regression

Fuzzy–frequency ratio model for avalanche susceptibility mapping

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International Journal of Digital Earth 2016年第12期9卷 1168-1184页

作者： Satish kumar Snehmani pankaj kumar Srivastava Akshay Gore Mritunjay kumar Singh College of Engineering Studies University of Petroleum&Energy Studies(UPES)DehradunUttarakhandIndia Snow and Avalanche Study Establishment Defence Research&Development Organisation(DRDO)ChandigarhIndia Spatial Strokes Technologies Private Limited ZirakpurPunjabIndia

Avalanche activities in the Indian Himalaya cause the majority of fatalities and responsible for heavy damage to the *** susceptibility maps assist decision-makers and planners to execute suitable measures to reduce the avalanche *** the present study,a probabilistic data-driven geospatial fuzzy–frequency ratio(fuzzy–FR)model is proposed and developed for avalanche susceptibility mapping,especially for the large undocumented *** fuzzy–FR model for avalanche susceptibility mapping is initially developed and applied for Lahaul-Spiti *** fuzzy–FR model utilized the six avalanche occurrence factors(***,aspect,curvature,elevation,terrain roughness and vegetation cover)and one referent avalanche inventory map to generate the avalanche susceptibility *** 292 documented avalanche locations from the avalanche inventory map,233(80%)were used for training the model and remaining 59(20%)were used for validation of the *** avalanche susceptibility map is validated by calculating the area under the receiver operating characteristic curve(ROC-AUC)*** validation of the results using ROC-AUC technique,the success rate and prediction rate were *** values of success rate and prediction rate were 94.07%and 91.76%,*** validation of results using ROC-AUC indicated the fuzzy–FR model is appropriate for avalanche susceptibility mapping.

关键词： Snow avalanche avalanche susceptibility mapping GIS fuzzy–frequency ratio(fuzzy–FR)model Lahaul&Spiti

Trio-Geometric mean-based three-stage Runge–Kutta algorithm to solve initial value problem arising in autonomous systems

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International Journal of Modeling, Simulation, and Scientific Computing 2018年第4期9卷 83-94页

作者： Vijeyata Chauhan pankaj kumar Srivastava Department of Mathematics Jaypee Institute of Information Technology Noida-201304 India

In the present worldwide scenario,plenty of problems arising in science and engineering which can be modeled as differential equations and out of these,autonomous system has become a subject of great *** laws of physics in which time is considered as an independent variable are expressed as autonomous *** this paper,Runge–Kutta(RK)three-stage geometric mean method is used to solve the initial value problem arises in autonomous *** method is discussed in detail,convergence of method is discussed,the accuracy and efficiency of the method are proved by considering a numerical *** result is compared to some other methods and proposed method is found to be more *** detailed analysis of error estimation confirms that proposed method is more efficient as compared to other methods.

关键词： Autonomous IVP geometric mean absolute error explicit Runge-Kutta method.

Measurement and validation of tsunami Eigen values for the various water wave conditions

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Journal of Ocean Engineering and Science 2020年第1期5卷 41-54页

作者： Sudhir kumar Chaturvedi Ugur Guven pankaj kumar Srivastava Department of Aerospace Engineering University of Petroleum and Energy StudiesDehradun 248007India Department of International Affairs University of Petroleum and Energy StudiesDehradun 248007India Department of Petroleum Engineering&Earth Sciences University of Petroleum and Energy StudiesDehradun 248007India

This paper proposes the mathematical model to investigate how to compute and analyze the tsunami wave parameters and the retrieval of its early warning using remote sensing technique to improve the detection *** different methods available for the evaluation of the tsunami detection systems are also *** research work is to compute and analyze the tsunami wave parameters such as Eigen functions in deep,intermediate and shallow water *** computational and algorithmic analysis of tsunami wave parameters are achieved in three steps:the first step is to calculate the earthquake fault parameters such as length,width,area and displacement from the epicenter,which corresponds to the effect of its variation with respect to the earthquake *** variation of each fault parameters have been measured and recorded out over the certain moment of magnitudes(M).This shows smaller values as compared to the earthquake magnitude M 9.5 at which all the parameters shows very large *** second step involves the measurements of water wave angular frequency in deep,intermediate and shallower region of *** values of angular frequencies in deep water shows the lesser response as compared to other two water conditions because,in deep water the angular velocity of water particles travels with the lesser speed as compared to the shallower region as per Airy’s wave *** simulation results show the angular velocity in Deep Ocean is very less,moderate in the intermediate water and very high on the coastal *** indicates the higher impact on coastal *** third step involves the simulation study of measurement of tsunami Eigen functions such as orbital velocity,acceleration,wave potential in deep,intermediate and shallower water *** simulation result shows the resultant orbital velocity and accelerations in deep,intermediate and shallow water regions provides the similar response as angular velocity due to same proportion of the

关键词： Tsunami Eigen functions Monitoring Detection.

Spatial distribution of fossil fuel derived CO_(2) over India using radiocarbon measurements in crop plants

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Journal of Environmental Sciences 2023年第2期124卷 19-30页

作者： Rajveer Sharma Ravi kumar Kunchala Sunil Ojha pankaj kumar Satinath Gargari Sundeep Chopra Inter University Accelerator Centre New Delhi 110067India Centre for Atmospheric Sciences Indian Institute of Technology DelhiNew Delhi 110016India

Examining the contribution of fossil fuel CO_(2) to the total CO_(2) changes in the atmosphere is of primary concern due to its alarming levels of fossil fuel emissions over the globe,specifically developing *** radiocarbon represents an important observational constraint and utilized to trace fossil fuel derived CO_(2)(CO_(2ff))in the *** the first time,we have presented a detailed analysis on the spatial distribution of fossil fuel derived CO_(2)(CO_(2ff))over India using radiocarbon(Δ14C)measurements during three-year *** shows that theΔ14C values are varying between 29.33‰ to-34.06‰ across India in the year 2017,where highest value belongs to a location from Gujarat while lowest value belongs to a location from *** on the14C patterns,spatial distributions of CO_(2ff) mole fractions have been determined over India and the calculated values of CO_(2ff) mole fractions are varying between 4.85 ppm to 26.59 ppm across *** is also noticed that the highest CO_(2ff) mole fraction is observed as 26.59 ppm from a site in ***_(2ff) mole fraction values from four high altitude sites are found to be varied between 4.85 ppm to 14.87 *** of sampling different crop plants from the same growing season and different crop plant organs(grains,leaves,stems)on theΔ14C and CO_(2ff) have been *** and intra seasonal variations in theΔ14C and CO_(2ff) mole fractions have also been analyzed from a rural location(Dholpur,Rajasthan).

关键词： Carbon dioxide Crop plants Fossil fuel CO_(2) Radiocarbon measurements