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Power Generalized Weibull Distribution Based on Record Values and Associated Inferences with Bladder Cancer Data Example

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Communications in Mathematics and Statistics 2024年第2期12卷 213-238页

作者： Devendra kumar Manoj kumar jagdish Saran Department of statistics Central University of HaryanaJant-PaliMahendergarhIndia Department of Statistics University of DelhiDelhiIndia

The power generalized Weibull distribution has been proposed recently by[24]as an alternative to the gamma,Weibull and the exponentiated Weibull *** power generalized Weibull family is suitable for modeling data that indicate nonmonotone hazard rates and can be used in survival analysis and reliability *** andﬂexibility of the family are illustrated by reanalyzing Efron’s data pertaining to a head-and-neck cancer clinical *** data involve censoring and indicate unimodal hazard *** this distribution,some recurrence relations are established for the single and product moments of upper record ***,using these relations,we have obtained means,variances and covariances of upper record values from samples of sizes up to 10 for various values of the parameters and present them inﬁ*** data set is analyzed to illustrate theﬂexibility and importance of the model.

关键词： Record values Moments Characterization Power generalized Weibull distribution

Support pressure for circular tunnels in two layered undrained clay

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 135-148页

作者： Bibhash kumar jagdish Prasad Sahoo Department of Civil Engineering National Institute of TechnologyUttarakhand246174India Department of Civil Engineering Indian Institute of TechnologyRoorkee247667India

To estimate the required support pressure for stability of circular tunnels in two layered clay under undrained condition,numerical solutions are developed by performing finite element lower bound limit analysis in conjunction with second-order cone *** support system is assumed to offer uniform internal compressive pressure on its *** the literature,it is known that the stability of tunnels depends on the overburden pressure acting over it,which is a function of undrained cohesion and unit weight of soil,and cover of *** a tunnel is constructed in layered undrained clay,the stability depends on the undrained shear strength,unit weight,and thickness of one layer relative to the other *** the present study,the solutions are presented in a form of dimensionless charts which can be used for design of tunnel support systems for different combinations of ratios of unit weight and undrained shear strength of upper layer to those of lower layer,thickness of both layers,and total soil cover depth.

关键词： Finite elements Layered clay Limit analysis Stability of tunnels

Rutting prediction models for flexible pavement structures: A review of historical and recent developments

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Journal of Traffic and Transportation Engineering(English Edition) 2021年第3期8卷 315-338页

作者： Auinash kumar Singh jagdish Prasad Sahoo Department of Civil Engineering Indian Institute of Technology RoorkeeRoorkee 247667India Department of Civil Engineering Indian Institute of Technology KanpurKanpur 208016India

Rutting is the major distress mode in flexible pavements occurring due to the repeated movement of traffic loading. Deformation in the pavements comprise of both recoverable(elastic) and irrecoverable(plastic) part. Overall deformation occurring in the flexible pavement system due to continuous vehicular movement is contributed from all the components of pavement. A number of empirical models have been proposed by several researchers for analysis and prediction of accumulated rutting in different components of pavement. The accumulated permanent strain has been expressed as the function of the number of load applications and deviator stress applications in most of the models proposed;however, factors such as stress state, moisture content, material type and environmental conditions also impose a significant influence on the permanent deformation characteristics of pavement materials under cyclic loading. In this article, a comprehensive review has been carried out covering every aspect of deformation related to distress occurring in pavements. Important rut models, modeling approaches and modern concepts in the rutting analysis of pavement structures have been presented. In addition to review, fallacy existing in the current design practices related to adaptation of stiffness parameters and negligence of shear strength aspect of subgrade soil has been also presented with the support of literatures.

关键词： Road engineering Permanent deformation Rutting models Resilient modulus Shear strength

Analysis of Age Dependent Effects of Heat Stress on EEG Frequency Components in Rats

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Biomedical and Environmental Sciences 2009年第2期22卷 141-150页

作者： rakesh kumar SINHA Department of Biomedical Instrumentation Birla Institute of Technology

Objective To demonstrate changes in different frequencies of cerebral electrical activity or electroencephalogram （EEG） following exposure to high environmental heat in three different age groups of freely moving rats. Methods Rats were divided into three groups （i） acute heat stress - subjected to a single exposure for four hours at 38 ℃; （ii） chronic heat stress exposed for 21 days daily for one hour at 38 ℃, and （iii） handling control groups. The digital polygraphic sleep-EEG recordings were performed just after the heat exposure from acute stressed rats and on 22nd day from chronic stressed rats by simultaneous recording of cortical EEG, EOG （electrooculogram）, and EMG （electromyogram）. Further, power spectrum analyses were performed to analyze the effects of heat stress. Results The frequency analysis of EEG signals following exposure to high environmental heat revealed that in all three age groups of rats, changes in higher frequency components （β2） were significant in all sleep-wake states following both acute and chronic heat stress conditions. After exposure to acute heat, significant changes in EEG frequencies with respect to their control groups were observed, which were reversed partly or fully in four hours of EEG recording. On the other hand, due to repetitive chronic exposure to hot environment, adaptive and long-term changes in EEG frequency patterns were observed. Conclusion The present study has exhibited that the cortical EEG is sensitive to environmental heat and alterations in EEG frequencies in different sleep-wake states due to heat stress can be differentiated efficiently by EEG power spectrum analysis.

关键词： Electroencephalogram Heat stress Power spectrum Sleep Rats

A Key Management Scheme Using(p,q)-Lucas Polynomials in Wireless Sensor Network

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China Communications 2021年第11期18卷 210-228页

作者： Amit kumar Gautam rakesh kumar Madan Mohan Malaviya University of Technology Gorakhpur-273001India

Wireless Sensor Network(WSN)has witnessed an unpredictable growth for the last few *** has many applications in various critical sectors such as real-time monitoring of nuclear power plant,disaster management,environment,military area ***,due to the distributed and remote deployment of sensor nodes in such networks,they are highly vulnerable to different security *** sensor network always needs a proficient key management scheme to secure data because of resourceconstrained *** polynomial based key management schemes are simple,but the computational complexity is a big *** polynomials,Fibonacci polynomials,Chebychev polynomials are used in Engineering,Physics,Combinatory and Numerical analysis *** this paper,we propose a key management scheme using(p,q)-Lucas polynomial to improve the security of ***(p,q)-Lucas polynomial,p represents a random base number while q represents a substitute value of x in the *** value of p is unique,and q is different according to communication between *** of the proposed method on several parameters such as computational overhead,efficiency and storage cost have been performed and compared with existing related *** analysis demonstrates that the proposed(p,q)-Lucas polynomial based key management scheme outperforms over other polynomials in terms of the number of keys used and efficiency.

关键词： key management lucas polynomial WSN security pairwise key distribution key generation hierarchical key management

Surface Modification Aspects for Improving Biomedical Properties in Implants:A Review

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 213-241页

作者： J.Sharath kumar rakesh kumar Rajeev Verma Industrial and Production Department Dr B R Ambedkar National Institute of Technology JalandharJalandharPunjab144008India

The primary focus during surgery is to ensure successful implantation by achieving long-term and stable fixation of *** surgery is now more focused on the development of novel biomaterials intended to improve implant *** obtain a better understanding of metal implants,this article investigated the causes of material failures in certain cases and analysed a few case *** interaction between the implant and bone tissue was a crucial aspect of successful implantation,and this study explored the factors influencing this interaction as well as ways to improve *** modern approaches used for modifying implant surfaces were systematically illustrated and briefly *** spray coatings were often favoured because of their wide range of coating materials,but other substantial surface modifications(such as friction stir processing and laser surface texturing)were also used for a selection of ***,implant surfaces with desirable features,such as biocompatibility,antibacterial properties,corrosion resistance,and wear resistance,were essential for optimising implant *** systematic review's main aim is to provide exhaustive reference information and a broad overview to advance the production and design of orthopaedic implants.

关键词： Biomaterials Surface treatments Thermal spray coatings Antibacterial Biocompatibility Corrosion resistance Wear resistance

MOLECULAR DYNAMICS SIMULATION OF POLYMER/CARBON NANOTUBE COMPOSITES

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Acta Mechanica Solida Sinica 2015年第4期28卷 409-419页

作者： Sumit Sharma rakesh Chandra Pramod kumar Navin kumar Department of Mechanical Engineering Dr.B.R.Ambedkar National Institute of Technology School of Mechanical Materials & Energy Engineering (SMMEE) Indian Institute of Technology

In this paper, we present classical molecular dynamics （MD） simulations of model polymer/CNT composites constructed by embedding a single wall （10,10） CNT into two different amorphous polymer matrices： poly（methyl methacrylate） and poly{（m-phenylene-vinylene）-co- [（2,5-dioctoxy-p-phenylene） vinylene]}, respectively, with different volume fractions. The simulation results support the idea that it is possible to use CNTs to mechanically reinforce an appropri- ate polymer matrix, especially in the longitudinal direction of the nanotube. The comparison of the simulation results with the macroscopic rule-of-mixtures for composite systems showed that for strong interfacial interactions, there can be large deviations of the results from the rule-of- mixtures. In order to verify this study, results obtained have been compared with those given by Elliott and Han （2007）.

关键词： nano-structures elasticity mechanical properties computational modeling

An overview of chemical enhanced oil recovery and its status in India

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Petroleum Science 2023年第4期20卷 2305-2323页

作者： Ganesh kumar Pothula rakesh kumar Vij Achinta Bera Department of Petroleum Engineering School of Energy TechnologyPandit Deendayal Energy UniversityGandhinagarGujarat382007India

India is currently producing crude oil from matured fields because of insufficient discoveries of new ***,in order to control the energy crisis in India,enhanced oil recovery(EOR)techniques are required to reduce the import of crude from the OPEC(Organization of the Petroleum Exporting Countries).This review mentions chemical EOR techniques(polymers,surfactants,alkali,nanoparticles,and combined alkali-surfactant-polymer flooding)and operations in *** EOR methods are one of the most efficient methods for oil *** efficiency is enhanced by interfacial tension(IFT)reduction using surfactants and alkali,and mobility control of injected water is done by adding a polymer to increase the volumetric sweep *** paper also reviews the current trend of chemical EOR,prospects of chemical EOR in Indian oilfields,the development of chemical EOR in India with their challenges raising with economics,and screening criteria for chemical EOR implementation on the field ***,the review gives a brief idea about chemical EOR implementation in Indian oilfields in future prospects to increase the additional oil recovery from existing depleted fields to reduce the import of crude *** outcome of this review depicts all chemical EOR operations and recovery rates both at the laboratory scale and field scale around the *** additional recovery rates are compared from various chemical EOR methods like conventional chemical flooding methods and conventional chemicals combined with nanoparticles on a laboratory *** development of chemical EOR in the past few decades and the EOR policy given by the government of India has been mentioned in this *** analysis provides an idea about enhanced recovery screening and implementation of chemical EOR methods in existing fields will significantly reduce the energy crisis in India.

关键词： Chemical enhanced oil recovery Surfactant flooding Polymer flooding Indian oilfields Enhanced oil recovery challenges in India Screening criteria

Design analysis for ultra-low crosstalk in high core count heterogeneous multicore fiber

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Optoelectronics Letters 2021年第10期17卷 616-621页

作者： Dablu kumar rakesh Ranjan OFC and Photonics Lab Department of Electronics and Communication EngineeringNational Institute of Technology PatnaPatna 800005India

Design analysis of high core count(36-core,37-core)un-coupled multicore fiber(MCF)using the heterogeneous core has been proposed,to achieve the high spatial efficiency and ultra-low crosstalk(~-81 d B/100 km)under the limited cladding diameter of 300μ*** realize the ultra-low crosstalk level between the neighboring cores,the combination of two crosstalk reduction approaches,trench-assisted(TA)core and propagation direction interleaving(PDI)technique has been *** forward and backward crosstalk characterizations have been studied in heterogeneous MCF with respect to fiber bending radius,wavelength,transmission distance,and core-pitch with both normal step-index and trench-assisted cores under single-mode propagation condition.

关键词： crosstalk fiber trench