A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools(NCMTs) reveal zero failures after a reliability test. Thus...A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools(NCMTs) reveal zero failures after a reliability test. Thus, the zero-failure data form and corresponding Bayesian model are developed to solve the zero-failure problem of NCMTs, for which no previous suitable statistical model has been developed. An expert-judgment process that incorporates prior information is presented to solve the difficulty in obtaining reliable prior distributions of Weibull parameters. The equations for the posterior distribution of the parameter vector and the Markov chain Monte Carlo(MCMC) algorithm are derived to solve the difficulty of calculating high-dimensional integration and to obtain parameter estimators. The proposed method is applied to a real case; a corresponding programming code and trick are developed to implement an MCMC simulation in Win BUGS, and a mean time between failures(MTBF) of 1057.9 h is obtained. Given its ability to combine expert judgment, prior information, and data, the proposed reliability modeling and assessment method under the zero failure of NCMTs is validated.展开更多
As the web-server based business is rapidly developed and popularized, how to evaluate and improve the reliability of web-servers has been extremely important. Although a large num- ber of software reliability growth ...As the web-server based business is rapidly developed and popularized, how to evaluate and improve the reliability of web-servers has been extremely important. Although a large num- ber of software reliability growth models （SRGMs）, including those combined with multiple change-points （CPs）, have been available, these conventional SRGMs cannot be directly applied to web soft- ware reliability analysis because of the complex web operational profile. To characterize the web operational profile precisely, it should be realized that the workload of a web server is normally non-homogeneous and often observed with the pattern of random impulsive shocks. A web software reliability model with random im- pulsive shocks and its statistical analysis method are developed. In the proposed model, the web server workload is characterized by a geometric Brownian motion process. Based on a real data set from IIS server logs of ICRMS website （www.icrms.cn）, the proposed model is demonstrated to be powerful for estimating impulsive shocks and web software reliability.展开更多
Recently, the physics-of-failure(PoF) method has been more and more popular in engineering to understand the failure mechanisms(FMs) of products.However, due to the lack of system modeling methods and problem-solving ...Recently, the physics-of-failure(PoF) method has been more and more popular in engineering to understand the failure mechanisms(FMs) of products.However, due to the lack of system modeling methods and problem-solving algorithms,the information of FMs cannot be used to evaluate system reliability.This paper presents a system reliability evaluation method with failure mechanism tree(FMT) considering physical dependency(PDEP) such as competition, trigger, acceleration, inhibition, damage accumulation, and parameter combination.And the binary decision diagram(BDD) analytical algorithm is developed to establish a system reliability model.The operation rules of ite operators for generating BDD are discussed.The flow chart of system reliability evaluation method based on FMT and BDD is proposed.The proposed method is applied in the case of an electronic controller drive unit.Results show that the method is effective to evaluate system reliability from the perspective of FM.展开更多
Testing-effort（TE） and imperfect debugging（ID） in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models（SRGMs）. For describing the S-shaped...Testing-effort（TE） and imperfect debugging（ID） in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models（SRGMs）. For describing the S-shaped varying trend of TE increasing rate more accurately, first, two S-shaped testing-effort functions（TEFs）, i.e.,delayed S-shaped TEF（DS-TEF） and inflected S-shaped TEF（IS-TEF）, are proposed. Then these two TEFs are incorporated into various types（exponential-type, delayed S-shaped and inflected S-shaped） of non-homogeneous Poisson process（NHPP）SRGMs with two forms of ID respectively for obtaining a series of new NHPP SRGMs which consider S-shaped TEFs as well as ID. Finally these new SRGMs and several comparison NHPP SRGMs are applied into four real failure data-sets respectively for investigating the fitting and prediction power of these new SRGMs.The experimental results show that：（i） the proposed IS-TEF is more suitable and flexible for describing the consumption of TE than the previous TEFs;（ii） incorporating TEFs into the inflected S-shaped NHPP SRGM may be more effective and appropriate compared with the exponential-type and the delayed S-shaped NHPP SRGMs;（iii） the inflected S-shaped NHPP SRGM considering both IS-TEF and ID yields the most accurate fitting and prediction results than the other comparison NHPP SRGMs.展开更多
Due to the randomness and time dependence of the factors affecting software reliability, most software reliability models are treated as stochastic processes, and the non-homogeneous Poisson process(NHPP) is the most ...Due to the randomness and time dependence of the factors affecting software reliability, most software reliability models are treated as stochastic processes, and the non-homogeneous Poisson process(NHPP) is the most used one.However, the failure behavior of software does not follow the NHPP in a statistically rigorous manner, and the pure random method might be not enough to describe the software failure behavior. To solve these problems, this paper proposes a new integrated approach that combines stochastic process and grey system theory to describe the failure behavior of software. A grey NHPP software reliability model is put forward in a discrete form, and a grey-based approach for estimating software reliability under the NHPP is proposed as a nonlinear multi-objective programming problem. Finally, four grey NHPP software reliability models are applied to four real datasets, the dynamic R-square and predictive relative error are calculated. Comparing with the original single NHPP software reliability model, it is found that the modeling using the integrated approach has a higher prediction accuracy of software reliability. Therefore, there is the characteristics of grey uncertain information in the NHPP software reliability models, and exploiting the latent grey uncertain information might lead to more accurate software reliability estimation.展开更多
A kind of hybrid reliability model is presented to solve the fatigue reliability problems of steel bridges. The cumulative damage model is one kind of the models used in fatigue reliability analysis. The parameter cha...A kind of hybrid reliability model is presented to solve the fatigue reliability problems of steel bridges. The cumulative damage model is one kind of the models used in fatigue reliability analysis. The parameter characteristics of the model can be described as probabilistic and interval. The two-stage hybrid reliability model is given with a theoretical foundation and a solving algorithm to solve the hybrid reliability problems. The theoretical foundation is established by the consistency relationships of interval reliability model and probability reliability model with normally distributed variables in theory. The solving process is combined with the definition of interval reliability index and the probabilistic algorithm. With the consideration of the parameter characteristics of the S-N curve, the cumulative damage model with hybrid variables is given based on the standards from different countries. Lastly, a case of steel structure in the Neville Island Bridge is analyzed to verify the applicability of the hybrid reliability model in fatigue reliability analysis based on the AASHTO.展开更多
A typical man-machine-environment system is composed of astronaut, vehicle and space environment in the course of manned spaceflight. In this paper, the important role played by man and the factors on his capability i...A typical man-machine-environment system is composed of astronaut, vehicle and space environment in the course of manned spaceflight. In this paper, the important role played by man and the factors on his capability in vehicle system have been described, and a stress-strength human reliability model is also put forward. In the end, it must be systematically considered to raise the astronaut's reliability.展开更多
As a peculiar product in China today,farm vehicles play an important role in economic construction and development of the countryside,but its work reliability remains low.In this paper truncated tracking was used to s...As a peculiar product in China today,farm vehicles play an important role in economic construction and development of the countryside,but its work reliability remains low.In this paper truncated tracking was used to solve the low reliability of farm vehicles.Relevant reliability data were obtained by tracking a certain model vehicle and conducting reliability experiments.Data analysis revealed the weakest part of the vehicle system was the engine assembly.The theory of Artificial Neural Network was employed to estimate a parameter of the reliability model based on self-adaptive linear neural network,and the reliability function educed by the estimation could provide important theory references for reliability reassignment,manufacture and management of farm transport vehicles.展开更多
The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated...The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated that the objective of catalyst mechanics research is to establish mechanical reliability model of converters using solid catalysts.展开更多
基金Project(2014ZX04014-011)supported by State Key Science&Technology Program of ChinaProject([2016]414)supported by the 13th Five-year Program of Education Department of Jilin Province,China
文摘A new problem that classical statistical methods are incapable of solving is reliability modeling and assessment when multiple numerical control machine tools(NCMTs) reveal zero failures after a reliability test. Thus, the zero-failure data form and corresponding Bayesian model are developed to solve the zero-failure problem of NCMTs, for which no previous suitable statistical model has been developed. An expert-judgment process that incorporates prior information is presented to solve the difficulty in obtaining reliable prior distributions of Weibull parameters. The equations for the posterior distribution of the parameter vector and the Markov chain Monte Carlo(MCMC) algorithm are derived to solve the difficulty of calculating high-dimensional integration and to obtain parameter estimators. The proposed method is applied to a real case; a corresponding programming code and trick are developed to implement an MCMC simulation in Win BUGS, and a mean time between failures(MTBF) of 1057.9 h is obtained. Given its ability to combine expert judgment, prior information, and data, the proposed reliability modeling and assessment method under the zero failure of NCMTs is validated.
基金supported by the International Technology Cooperation Project of Guizhou Province(QianKeHeWaiGZi[2012]7052)the National Scientific Research Project for Statistics(2012LZ054)
文摘As the web-server based business is rapidly developed and popularized, how to evaluate and improve the reliability of web-servers has been extremely important. Although a large num- ber of software reliability growth models （SRGMs）, including those combined with multiple change-points （CPs）, have been available, these conventional SRGMs cannot be directly applied to web soft- ware reliability analysis because of the complex web operational profile. To characterize the web operational profile precisely, it should be realized that the workload of a web server is normally non-homogeneous and often observed with the pattern of random impulsive shocks. A web software reliability model with random im- pulsive shocks and its statistical analysis method are developed. In the proposed model, the web server workload is characterized by a geometric Brownian motion process. Based on a real data set from IIS server logs of ICRMS website （www.icrms.cn）, the proposed model is demonstrated to be powerful for estimating impulsive shocks and web software reliability.
基金supported by the National Natural Science Foundation of China (6150301462073009)。
文摘Recently, the physics-of-failure(PoF) method has been more and more popular in engineering to understand the failure mechanisms(FMs) of products.However, due to the lack of system modeling methods and problem-solving algorithms,the information of FMs cannot be used to evaluate system reliability.This paper presents a system reliability evaluation method with failure mechanism tree(FMT) considering physical dependency(PDEP) such as competition, trigger, acceleration, inhibition, damage accumulation, and parameter combination.And the binary decision diagram(BDD) analytical algorithm is developed to establish a system reliability model.The operation rules of ite operators for generating BDD are discussed.The flow chart of system reliability evaluation method based on FMT and BDD is proposed.The proposed method is applied in the case of an electronic controller drive unit.Results show that the method is effective to evaluate system reliability from the perspective of FM.
基金supported by the Pre-research Foundation of CPLA General Equipment Department
文摘Testing-effort（TE） and imperfect debugging（ID） in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models（SRGMs）. For describing the S-shaped varying trend of TE increasing rate more accurately, first, two S-shaped testing-effort functions（TEFs）, i.e.,delayed S-shaped TEF（DS-TEF） and inflected S-shaped TEF（IS-TEF）, are proposed. Then these two TEFs are incorporated into various types（exponential-type, delayed S-shaped and inflected S-shaped） of non-homogeneous Poisson process（NHPP）SRGMs with two forms of ID respectively for obtaining a series of new NHPP SRGMs which consider S-shaped TEFs as well as ID. Finally these new SRGMs and several comparison NHPP SRGMs are applied into four real failure data-sets respectively for investigating the fitting and prediction power of these new SRGMs.The experimental results show that：（i） the proposed IS-TEF is more suitable and flexible for describing the consumption of TE than the previous TEFs;（ii） incorporating TEFs into the inflected S-shaped NHPP SRGM may be more effective and appropriate compared with the exponential-type and the delayed S-shaped NHPP SRGMs;（iii） the inflected S-shaped NHPP SRGM considering both IS-TEF and ID yields the most accurate fitting and prediction results than the other comparison NHPP SRGMs.
基金supported by the National Natural Science Foundation of China (71671090)the Fundamental Research Funds for the Central Universities (NP2020022)the Qinglan Project of Excellent Youth or Middle-Aged Academic Leaders in Jiangsu Province。
文摘Due to the randomness and time dependence of the factors affecting software reliability, most software reliability models are treated as stochastic processes, and the non-homogeneous Poisson process(NHPP) is the most used one.However, the failure behavior of software does not follow the NHPP in a statistically rigorous manner, and the pure random method might be not enough to describe the software failure behavior. To solve these problems, this paper proposes a new integrated approach that combines stochastic process and grey system theory to describe the failure behavior of software. A grey NHPP software reliability model is put forward in a discrete form, and a grey-based approach for estimating software reliability under the NHPP is proposed as a nonlinear multi-objective programming problem. Finally, four grey NHPP software reliability models are applied to four real datasets, the dynamic R-square and predictive relative error are calculated. Comparing with the original single NHPP software reliability model, it is found that the modeling using the integrated approach has a higher prediction accuracy of software reliability. Therefore, there is the characteristics of grey uncertain information in the NHPP software reliability models, and exploiting the latent grey uncertain information might lead to more accurate software reliability estimation.
基金Projects(51178042,51578047)supported by the National Natural Science Foundation of ChinaProject(C14JB00340)supported by the Innovative Research Fund in Beijing Jiaotong University,ChinaProject(2014-ZJKJ-03)supported by Science and Technology Research and Development Fund of the China Communications Construction Co.,LTD
文摘A kind of hybrid reliability model is presented to solve the fatigue reliability problems of steel bridges. The cumulative damage model is one kind of the models used in fatigue reliability analysis. The parameter characteristics of the model can be described as probabilistic and interval. The two-stage hybrid reliability model is given with a theoretical foundation and a solving algorithm to solve the hybrid reliability problems. The theoretical foundation is established by the consistency relationships of interval reliability model and probability reliability model with normally distributed variables in theory. The solving process is combined with the definition of interval reliability index and the probabilistic algorithm. With the consideration of the parameter characteristics of the S-N curve, the cumulative damage model with hybrid variables is given based on the standards from different countries. Lastly, a case of steel structure in the Neville Island Bridge is analyzed to verify the applicability of the hybrid reliability model in fatigue reliability analysis based on the AASHTO.
文摘A typical man-machine-environment system is composed of astronaut, vehicle and space environment in the course of manned spaceflight. In this paper, the important role played by man and the factors on his capability in vehicle system have been described, and a stress-strength human reliability model is also put forward. In the end, it must be systematically considered to raise the astronaut's reliability.
基金Supported by the Education Project of Heilongjiang Province Office(9551022)
文摘As a peculiar product in China today,farm vehicles play an important role in economic construction and development of the countryside,but its work reliability remains low.In this paper truncated tracking was used to solve the low reliability of farm vehicles.Relevant reliability data were obtained by tracking a certain model vehicle and conducting reliability experiments.Data analysis revealed the weakest part of the vehicle system was the engine assembly.The theory of Artificial Neural Network was employed to estimate a parameter of the reliability model based on self-adaptive linear neural network,and the reliability function educed by the estimation could provide important theory references for reliability reassignment,manufacture and management of farm transport vehicles.
文摘The mechanics of porous catalyst paricles has been discussed and outlined. Concept of brittle fracture, statistical model of single-particle strength, and bulk crushing strength model were introduced. It is elucidated that the objective of catalyst mechanics research is to establish mechanical reliability model of converters using solid catalysts.
