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Convergence of Weak Galerkin Finite Element Method for Second Order Linear Wave Equation in Heterogeneous Media

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 323-347页

作者： Bhupen Deka Papri Roy Naresh kumar raman kumar Department of Mathematics Indian Institute of Technology GuwahatiGuwahati 781039India

Weak Galerkin finite element method is introduced for solving wave equation with interface on weak Galerkin finite element space(Pk(K),P_(k−1)(∂K),[P_(k−1)(K)]^(2)).Optimal order a priori error estimates for both space-discrete scheme and implicit fully discrete scheme are derived in L1(L2)*** method uses totally discontinuous functions in approximation space and allows the usage of finite element partitions consisting of general polygonal *** element algorithm presented here can contribute to a variety of hyperbolic problems where physical domain consists of heterogeneous media.

关键词： Wave equation heterogeneous medium finite element method weak Galerkin method semidiscrete and fully discrete schemes optimal error estimates

Obtaining Crisp Priorities for Triangular and Trapezoidal Fuzzy Judgments

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Computer Systems Science & Engineering 2022年第4期41卷 157-170页

作者： raman kumar Goyal Jaskirat Singh Nidhi Kalra Anshu Parashar Gagan Singla Sakshi Kaushal Computer Science and Engineering Department Thapar Institute of Engineering and TechnologyPatialaPunjabIndia Computer Science and Engineering University Institute of Engineering and TechnologyPanjab UniversityChandigarhIndia

This paper proposes anoptimal fuzzy-based model for obtaining crisp priorities for Fuzzy-AHP comparison *** judgments cannot be given for real-life situations,as most of these include some level of fuzziness and *** these situations,judgments are represented by the set of fuzzy *** of the fuzzy optimization models derive crisp priorities for judgments repre-sented with Triangular Fuzzy Numbers(TFNs)*** do not work for other types of Triangular Shaped Fuzzy Numbers(TSFNs)and Trapezoidal Fuzzy Numbers(TrFNs).To overcome this problem,a sum of squared error(SSE)based optimization model is *** some other methods,the proposed model derives crisp weights from all of the above-mentioned fuzzy judgments.A fuzzy number is simulated using the Monte Carlo method.A threshold-based constraint is also applied to minimize the deviation from the initial *** Algorithm(GA)is used to solve the optimization *** have also conducted casestudiesto show the proposed approach’s advantages over the *** show that the proposed model outperforms other models to minimize SSE and deviation from initial ***,the proposed model can be applied in various real time scenarios as it can reduce the SSE value upto 29%compared to the existing studies.

关键词： Analytic hierarchy process comparison matrices priority vectors fuzzy judgments triangular fuzzy numbers triangular-shaped fuzzy numbers trapezoidal fuzzy numbers

Driving Style Recognition System Using Smartphone Sensors Based on Fuzzy Logic

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Computers, Materials & Continua 2021年第11期69卷 1967-1978页

作者： Nidhi Kalra raman kumar Goyal Anshu Parashar Jaskirat Singh Gagan Singla Department of Computer Science and Engineering Thapar Institute of Engineering and TechnologyPatiala147001PunjabIndia Computer Science and Engineering University Institute of Engineering and TechnologyPanjab University160014ChandigarhIndia

Every 24 seconds,someone dies on the road due to road accidents and it is the 8th leading cause of death and the first among children aged 15–29 years.1.35 million people globally die every year due to road traffic *** additional 20–50 million suffer from non-fatal injuries,often resulting in longterm *** costs around 3%of Gross Domestic Product to most countries,and it is a considerable economic *** governments have taken various measures such as better road infrastructures and strict enforcement of motor-vehicle laws to reduce these ***,there is still no remarkable reduction in the number of *** ensure driver safety and achieve vision of zero accidents,there is a great need to monitor drivers’driving *** of the existing driving behavior monitoring solutions are based on expensive hardware *** most people are using smartphones in the modern era,a system based on mobile application is proposed,which can reduce the cost for developing intelligent transport systems(ITS)to a large *** this paper,we utilize the accelerometer sensor data and the global positioning system(GPS)sensor deployed in smartphones to recognize driving and speeding events.A driving style recognition system based on fuzzy logic is designed to classify different driving styles and control reckless driving by taking the longitudinal/lateral acceleration and speed as input ***,the proposed system uses fuzzy logic rather than taking the crisp values of the *** indicate that the proposed system can classify reckless driving based on fuzzy logic and,therefore,reduce the number of accidents.

关键词： Fuzzy logic accelerometer global positioning system driving style

Oxide ancillary ligand-based europium β-diketonate complexes and their enhanced luminosity

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Rare Metals 2021年第10期40卷 2873-2881页

作者： Devender Singh Shri Bhagwan Anuj Dalal Kapeesha Nehra raman kumar Saini Kapoor Singh Anura Priyajith Simantilleke Sumit kumar Ishwar Singh Department of Chemistry Maharshi Dayanand UniversityRohtak 124001India Centre de Fisica Universidade of MinhoBraga 4710057Portugal Department of Chemistry DCR University of Science and TechnologyMurthal 131039India

Ternary materials of europium complex with2,2,6,6-tetramethyl-3,5-heptanedione(tmhd) ligand and aqua ligand as ancillary ligands have been prepared and characterized for various optoelectronic *** of hydrated complex [Eu(tmhd)_(3)(H_(2)O)_(2)] proceeded with triphenylphosphine oxide(TPPO) and pyridine-N-oxide(PNO) ancillary ligands were studied to develop novel complexes. The prepared complexes show good thermal stability. A comparative investigation of preparedmaterials[Eu(tmhd)_(3)(H_(2)O)_(2)],[Eu(tmhd)_(3)(TPPO)_(2)] and [Eu(tmhd)_(3)(PNO)_(2)] was conducted for their luminescent behaviors in order to obtain the role of ancillary ligand in the enhancement of illumination amount generated from europium(Eu^(3+)) ion. Color coordinates of prepared ternary complexes such as[Eu(tmhd)_(3)(H_(2)O)_(2)]with(x = 0.54,y = 0.32),[Eu(tmhd)_(3)(TPPO)_(2)] with(x = 0.56, y = 0.32) and[Eu(tmhd)_(3)(PNO)_(2)] with(x = 0.57, y = 0.33) indicated that these materials exhibited bright red emission in visible region spectrum. The complexes show a proficient energy transport pathway from the ligands to the innermost Eu^(3+)by means of an ancillary ligand-sensitized luminescence process. Interaction between the metal and ligand results in a distinguished effect on quantum efficiency(η) as well as on Judd–Ofelt intensity factor(Ω_(2)) of the prepared materials.

关键词： Ternary Eu^(3+)complexes Red emissive materials Photoluminescence Quantum efficiency Judd-Ofelt intensity Optoelectronic devices

Familial aggregation and heritability for cardiovascular risk factors: a family based study in Punjab, India

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Natural Science 2010年第7期2卷 732-736页

作者： raman kumar Bdarud Doza 不详

Background: It is well established that the people with elevated SBP, DBP, BMI and WHR are more prone to cardiovascular disease. However, very few studies have focused on the amount of familial aggregation and heritability of these cardiovascular risk factors in Indian population. Therefore, purpose of this study was to investigate the familial aggregation of blood pressures with respect to certain anthropometric traits and to determine the relative roles of heredity in the etiology of SBP and DBP in a sample of families with three generations. Methods: The study has been conducted through house to house family study among three generations such as offspring, parent and grandparent in a scheduled caste community (Ramdasia) in Punjab. A total of 1400 individuals, constituting 380 families were surveyed for blood pressure, pulse rate, pulse pressure and anthropometric measurements to study familial aggregation and heritability for cardiovascular risk factors. The analysis represents a multivariate model which includes the each individual family data for estimation of familial correlation and heritability. Results: All risk factors showed positive familial correlation but magnitudes are different in va rious pairs of combination. Correlations generally are higher among genetically close relatives such as brothersisters or parentoffspring and are lower among spouses. The estimated heri tabilities were 22% for systolic and 27% for diastolic blood pressure, 19% for BMI and 17% for WHR. Conclusions: These results indicate a strong familial aggregation of cardiovascular risk factors such as SBP and DBP in this population and also showed that this familial influence can be detected from anthropometric mea surements and genetic closeness. Almost all anthropometric variables were found to be significant with blood pressures among three ge nerations.

关键词： Familial Aggregation Heritability Risk Factors Ramdasia Population Punjab

A Note on the Effect of Negative Poisson’s Ratio on the Deformation of a Poroelastic Half-Space by Surface Loads

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Engineering（科研） 2010年第6期2卷 432-437页

作者： Sunita Rani raman kumar Sarva Jit Singh 不详

The aim of this note is to study the effect of negative Poisson’s ratio on the quasi-static deformation of a poroelastic half-space with anisotropic permeability and compressible fluid and solid constituents by surface loads. Two particular cases considered are: two-dimensional normal strip loading and axisymmetric normal disc loading. It is found that a negative Poisson’s ratio makes the Mandel-Cryer effect more prominent. It also results in an increase in the magnitude of the surface settlement.

关键词： Anisotropic Permeability Auxetic Material Negative Poisson’s Ratio Poroelastic Half-Space Quasi-Static Deformation Surface Loading

Hydro-uvarovite from Mantle Peridotites of Naga Hills Ophiolite: A Mineral Tracer for Neo-Tethyan Mantle Wedge Metasomatism

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 867-877页

作者： Anisha VERENCAR Abhishek SAHA Nilanjana SORCAR Sohini GANGULY Pankaj kumar Atul kumar SINGH CSIR-National Institute of Oceanography Dona PaulaGoa 403004India School of Earth Ocean and Atmospheric SciencesGoa UniversityTaleigao PlateauGoa 403206India National Centre for Earth Science Studies ThiruvananthapuramKeralaIndia Inter University Accelerator Centre(IUAC) New Delhi 110067India North-Eastern Hill University ShillongMeghalaya 793022India

Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.

关键词： uvarovite hydroxyl metasomatic alteration low-Cr diopsides serpentinization mantle peridotite

Direct laser writing of volumetric gradient index lenses and waveguides

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Light(Science & Applications) 2020年第1期9卷 89-102页

作者： Christian R.Ocier Corey A.Richards Daniel A.Bacon-Brown Qing Ding raman kumar Tanner J.Garcia Jorik van de Groep Jung-Hwan Song Austin J.Cyphersmith Andrew Rhode Andrea N.Perry Alexander J.Littlefield Jinlong Zhu Dajie Xie Haibo Gao Jonah F.Messinger Mark L.Brongersma Kimani C.Toussaint Jr Lynford L.Goddard Paul V.Braun Department of Materials Science and Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA Materials Research Laboratory University of Illinois at Urbana-ChampaignUrbanaILUSA Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-ChampaignUrbanaILUSA Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA Department of Materials Science and Engineering Stanford UniversityStanfordCAUSA Carl R.Woese Institute for Genomic Biology University of Illinois at Urbana-ChampaignUrbanaILUSA Department of Mechanical Science and Engineering University of Illinois at Urbana-ChampaignUrbanaILUSA

Direct laser writing(DLW)has been shown to render 3D polymeric optical components,including lenses,beam expanders,and mirrors,with submicrometer ***,these printed structures are limited to the refractive index and dispersive properties of the ***,we present the subsurface controllable refractive index via beam exposure(SCRIBE)method,a lithographic approach that enables the tuning of the refractive index over a range of greater than 0.3 by performing DLW inside photoresist-filled nanoporous silicon and silica *** the laser exposure during printing enables 3D submicron control of the polymer infilling and thus the refractive index and chromatic *** SCRIBE’s unprecedented index range and 3D writing accuracy has realized the world’s smallest(15μm diameter)spherical Luneburg lens operating at visible ***’s ability to tune the chromatic dispersion alongside the refractive index was leveraged to render achromatic doublets in a single printing step,eliminating the need for multiple photoresins and writing *** also has the potential to form multicomponent optics by cascading optical elements within a *** a demonstration,stacked focusing structures that generate photonic nanojets were fabricated inside porous ***,an all-pass ring resonator was coupled to a subsurface 3D *** measured quality factor of 4600 at 1550 nm suggests the possibility of compact photonic systems with optical interconnects that traverse multiple *** is uniquely suited for constructing such photonic integrated circuits due to its ability to integrate multiple optical components,including lenses and waveguides,without additional printed supports.

关键词： index refractive render

Graphene coatings for corrosion resistance of nickel and copper in acidic,alkaline and neutral environments

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Journal of Materials Science & Technology 2023年第11期142卷 124-133页

作者： R.K.Singh raman Abhishek kumar Arya Kevin Tomy Faisal A Dip Evelyn Lai Saad Al-Saadi Department of Mechanical&Aerospace Engineering Monash UniversityVic 3800Australia Department of Chemical&Biological Engineering Monash UniversityVic 3800Australia

Graphene coatings have been reported to provide impressive corrosion resistance to nickel(Ni)and copper(Cu),because of remarkable characteristics of inertness and impermeablity of ***,as the earlier investigations have generally been carried out in chloride environment,and it is important to understand the performance of graphene coating also in more aggressive environments such as acids and *** study investigated the electrochemical corrosion behaviour of bare and graphene-coated(by chemical vapour deposition(CVD))Ni and Cu in 0.5 M H_(2)SO_(4),0.1 M NaCl and 0.5 M NaOH *** tests and post corrosion characterisation revealed the improvement in the corrosion resistance of Ni due to multilayer graphene coating to be similar in the three solutions,i.e.,the robustness of the barrier property of the multilayer graphene is largely unaffected by the aggressiveness of the corrosive ***,the improvement in corrosion resistance of bare Ni due to multilayer graphene is considerably greater(nearly 3 orders of magnitude)in the most aggressive of the test solutions(0.5 M H_(2)SO_(4)).The improvement is considerably less in 0.5 M NaOH because bare Ni develops a robust passive layer in highly alkaline *** improvement in corrosion resistance of bare Cu is limited(within an order of magnitude)in the three solutions because Cu develops only 1-2 layers of graphene.

关键词： CVD graphene coatings Electrochemical impedance spectroscopy(EIS) Potentiodynamic polarization(PDP) raman spectroscopy