This paper introduces a new family of distributions defined in terms of quantile function.The quantile function introduced here is the sum of quantile functions of life time distributions called Burr Ⅲ and Weibull.Di...This paper introduces a new family of distributions defined in terms of quantile function.The quantile function introduced here is the sum of quantile functions of life time distributions called Burr Ⅲ and Weibull.Different distributional characteristics and reliability properties are included in the study.Method of Least Square and Method of L-moments are applied to estimate the parameters of the model.Two real life data sets are used to illustrate the performance of the model.展开更多
Inthispaper,theoptimumtestplanandparameterestimationfor3-stepstep-stress accelerated life tests in the presence of modified progressive Type-I censoring are discussed.It is assumed that the lifetime of test units foll...Inthispaper,theoptimumtestplanandparameterestimationfor3-stepstep-stress accelerated life tests in the presence of modified progressive Type-I censoring are discussed.It is assumed that the lifetime of test units follows a Lomax distribution with log of characteristic life being quadratic function of stress level.The maximum likelihood and Bayesian method are used to obtain the point and interval estimators of the model parameters.The Bayes estimates are obtained using Markov chain Monte Carlo simulation based on Gibbs sampling.The optimum plan for 3-step step-stress test under modified progressive Type-I censoring is developed which minimizes the asymptotic variance of the maximum likelihood estimators of log of scale parameter at design stress.Finally,the numerical study with sensitivity analysis is presented to illustrate the proposed study.展开更多
Regression models play a vital role in the study of data regarding survival of subjects.The Cox proportional hazards model for regression analysis has been frequently used in sur-vival modelling.In survival studies,it...Regression models play a vital role in the study of data regarding survival of subjects.The Cox proportional hazards model for regression analysis has been frequently used in sur-vival modelling.In survival studies,it is also possible that survival time may occur with multiple occurrences of event or competing risks.The situation of competing risks arises when there are more than one mutually exclusive causes of death(or failure)for the person(or subject).In this paper,we developed a parametric regression model using Gompertz distribution via the Cox proportional hazards model with competing risks.We discussed point and interval estimation of unknown parameters and cumulative cause-specific hazard function with maximum-likelihood method and Bayesian method of estimation.The Bayes estimates are obtained based on non-informative priors and symmetric as well as asym-metric loss functions.To observe the finite sample behaviour of the proposed model under both estimation procedures,we carried out a Monte Carlo simulation analysis.To demon-strate our methodology,we also included real data analysis.展开更多
Waardenburg syndrome is a rare disease characterized by sensorineural deafness in association with pigmentary defects. Depending on additional symptoms, WS have been classified into four types.Waardenburg syndrome typ...Waardenburg syndrome is a rare disease characterized by sensorineural deafness in association with pigmentary defects. Depending on additional symptoms, WS have been classified into four types.Waardenburg syndrome type 4, also called as Waardenburg Shah Syndrome is a very rare congenital disorder with astounding variable clinical expression, characterized by pigmentary abnormalities of the hair(A white forelock of hair, premature graying) and pigmentary changes of the iris such as heterochromia or homochromia irides, sensorineural deafness and Hirschsprung disease. Three genes have been bestowed so far in consociation with EDNRB, EDN3, and SOX10 genes. The pattern of inheritance is multifarious with the SOX10 mutation affiliation with autosomal dominant inheritance whereas the EDNRB and EDN3 genes are passed down in an autosomally recessive pattern.展开更多
The discovery of a giant comet (C/2014 UN271) at a distance of 29 AU in October 2014 and the later discovery in September 2021 of a dramatic brightening episode offers an ideal opportunity for verifying the prediction...The discovery of a giant comet (C/2014 UN271) at a distance of 29 AU in October 2014 and the later discovery in September 2021 of a dramatic brightening episode offers an ideal opportunity for verifying the predictions of a “biological” comet. The eruptions of the comet at a heliocentric distance of 20 AU are plausibly explained as due to high pressure venting of the products of microbial metabolism in radioactively heated subsurface lakes. The standard non-biological model of comets is woefully inadequate to account for eruptions at such large distances from the sun where surface temperatures are as low as 60 K.展开更多
Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperatur...Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored.展开更多
文摘This paper introduces a new family of distributions defined in terms of quantile function.The quantile function introduced here is the sum of quantile functions of life time distributions called Burr Ⅲ and Weibull.Different distributional characteristics and reliability properties are included in the study.Method of Least Square and Method of L-moments are applied to estimate the parameters of the model.Two real life data sets are used to illustrate the performance of the model.
文摘Inthispaper,theoptimumtestplanandparameterestimationfor3-stepstep-stress accelerated life tests in the presence of modified progressive Type-I censoring are discussed.It is assumed that the lifetime of test units follows a Lomax distribution with log of characteristic life being quadratic function of stress level.The maximum likelihood and Bayesian method are used to obtain the point and interval estimators of the model parameters.The Bayes estimates are obtained using Markov chain Monte Carlo simulation based on Gibbs sampling.The optimum plan for 3-step step-stress test under modified progressive Type-I censoring is developed which minimizes the asymptotic variance of the maximum likelihood estimators of log of scale parameter at design stress.Finally,the numerical study with sensitivity analysis is presented to illustrate the proposed study.
文摘Regression models play a vital role in the study of data regarding survival of subjects.The Cox proportional hazards model for regression analysis has been frequently used in sur-vival modelling.In survival studies,it is also possible that survival time may occur with multiple occurrences of event or competing risks.The situation of competing risks arises when there are more than one mutually exclusive causes of death(or failure)for the person(or subject).In this paper,we developed a parametric regression model using Gompertz distribution via the Cox proportional hazards model with competing risks.We discussed point and interval estimation of unknown parameters and cumulative cause-specific hazard function with maximum-likelihood method and Bayesian method of estimation.The Bayes estimates are obtained based on non-informative priors and symmetric as well as asym-metric loss functions.To observe the finite sample behaviour of the proposed model under both estimation procedures,we carried out a Monte Carlo simulation analysis.To demon-strate our methodology,we also included real data analysis.
文摘Waardenburg syndrome is a rare disease characterized by sensorineural deafness in association with pigmentary defects. Depending on additional symptoms, WS have been classified into four types.Waardenburg syndrome type 4, also called as Waardenburg Shah Syndrome is a very rare congenital disorder with astounding variable clinical expression, characterized by pigmentary abnormalities of the hair(A white forelock of hair, premature graying) and pigmentary changes of the iris such as heterochromia or homochromia irides, sensorineural deafness and Hirschsprung disease. Three genes have been bestowed so far in consociation with EDNRB, EDN3, and SOX10 genes. The pattern of inheritance is multifarious with the SOX10 mutation affiliation with autosomal dominant inheritance whereas the EDNRB and EDN3 genes are passed down in an autosomally recessive pattern.
文摘The discovery of a giant comet (C/2014 UN271) at a distance of 29 AU in October 2014 and the later discovery in September 2021 of a dramatic brightening episode offers an ideal opportunity for verifying the predictions of a “biological” comet. The eruptions of the comet at a heliocentric distance of 20 AU are plausibly explained as due to high pressure venting of the products of microbial metabolism in radioactively heated subsurface lakes. The standard non-biological model of comets is woefully inadequate to account for eruptions at such large distances from the sun where surface temperatures are as low as 60 K.
文摘Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored.
