In this paper,we introduce a new four-parameter version of the traditional Weibull distribution.It is able to provide seven shapes of hazard rate,including constant,decreasing,increasing,unimodal,bathtub,unimodal then...In this paper,we introduce a new four-parameter version of the traditional Weibull distribution.It is able to provide seven shapes of hazard rate,including constant,decreasing,increasing,unimodal,bathtub,unimodal then bathtub,and bathtub then unimodal shapes.Some basic characteristics of the proposedmodel are studied,including moments,entropies,mean deviations and order statistics,and its parameters are estimated using the maximum likelihood approach.Based on the asymptotic properties of the estimators,the approximate confidence intervals are also taken into consideration in addition to the point estimators.We examine the effectiveness of the maximum likelihood estimators of the model’s parameters through simulation research.Based on the simulation findings,it can be concluded that the provided estimators are consistent and that asymptotic normality is a good method to get the interval estimates.Three actual data sets for COVID-19,engineering and blood cancer are used to empirically demonstrate the new distribution’s usefulness inmodeling real-world data.The analysis demonstrates the proposed distribution’s ability in modeling many forms of data as opposed to some of its well-known sub-models,such as alpha powerWeibull distribution.展开更多
An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mend...An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function（PDF） of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not itemtive circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative.展开更多
随着信息化建设的发展,高等学校积累了海量的教务数据,对该数据进行挖掘,并探讨建立高效的质量评价指标体系显得十分必要。首先,基于某高校学期内所有课程的评教大数据,从5项指标出发,采用熵权法定量计算各项指标的权重,建立了机器学习...随着信息化建设的发展,高等学校积累了海量的教务数据,对该数据进行挖掘,并探讨建立高效的质量评价指标体系显得十分必要。首先,基于某高校学期内所有课程的评教大数据,从5项指标出发,采用熵权法定量计算各项指标的权重,建立了机器学习的TOPSIS(Technique for order preference by similarity to an ideal solution)模型;然后,将大数据按照得分进行聚类分析,得到了相应的教学特征;最后,将课程考核平均绩点与各项指标得分进行相关分析,结果表明课程综合评价得分以及5项指标与课程成绩均呈现统计学上显著的相关性。展开更多
高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争...高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争力和核心竞争力两个子系统出发构建马拉松赛事竞争力评价指标体系,采用结构熵权法和均方差决策法进行主客观联合赋权,并以我国13个顶级马拉松赛事为例,完成其竞争力综合评价的实证研究。研究发现:(1)经本研究构建评价指标体系实证所得出的我国顶级马拉松赛事竞争力排序与Ga WC(Globalization and World Cities)组织的世界城市排名结果具有较高匹配度,且这一结果较好契合现状认知,表明该评价指标体系和方法可为其他同类体育赛事竞争力的评价研究提供借鉴。(2)实证中马拉松赛事的基础竞争力与举办城市本身的社会经济实力密切相关,香港、北京、上海和广州等国际一流城市举办的马拉松赛事基础竞争力远远高于衡水等欠发达城市。(3)总体上第三方参度与和赛事水平在马拉松赛事核心竞争力中起着关键作用,台北、厦门、兰州等经济总量不大或中等偏上的城市马拉松赛事的核心竞争力排名比较靠前。(4)我国顶级马拉松赛事的综合竞争力排名从高到低为:香港、北京、广州、台北、上海、杭州、兰州、重庆、厦门、太原、深圳、东营和衡水。(5)我国顶级马拉松赛事竞争力可分为五个等级:香港、北京、广州和上海的马拉松赛事为高水平均衡型;台北和兰州的马拉松赛事为高水平单一型;杭州、重庆、太原和深圳的马拉松赛事为中等水平均衡型;厦门和东营的马拉松赛事为中等水平单一型;衡水马拉松赛事为低水平单一型。等级划分基础上还针对政府、组织者和参与者提出了发展运营、赛事组织、参与选择等方面的对策建议。展开更多
基金The Deanship of Scientific Research(DSR)at King Abdulaziz University,Jeddah,Saudi Arabia has funded this project under Grant No.(G-102-130-1443).
文摘In this paper,we introduce a new four-parameter version of the traditional Weibull distribution.It is able to provide seven shapes of hazard rate,including constant,decreasing,increasing,unimodal,bathtub,unimodal then bathtub,and bathtub then unimodal shapes.Some basic characteristics of the proposedmodel are studied,including moments,entropies,mean deviations and order statistics,and its parameters are estimated using the maximum likelihood approach.Based on the asymptotic properties of the estimators,the approximate confidence intervals are also taken into consideration in addition to the point estimators.We examine the effectiveness of the maximum likelihood estimators of the model’s parameters through simulation research.Based on the simulation findings,it can be concluded that the provided estimators are consistent and that asymptotic normality is a good method to get the interval estimates.Three actual data sets for COVID-19,engineering and blood cancer are used to empirically demonstrate the new distribution’s usefulness inmodeling real-world data.The analysis demonstrates the proposed distribution’s ability in modeling many forms of data as opposed to some of its well-known sub-models,such as alpha powerWeibull distribution.
基金Project(50378036) supported by the National Natural Science Foundation of China Project (200503) supported by the Foundation ofCommunications Department of Hunan Province, China
文摘An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function（PDF） of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not itemtive circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative.
文摘随着信息化建设的发展,高等学校积累了海量的教务数据,对该数据进行挖掘,并探讨建立高效的质量评价指标体系显得十分必要。首先,基于某高校学期内所有课程的评教大数据,从5项指标出发,采用熵权法定量计算各项指标的权重,建立了机器学习的TOPSIS(Technique for order preference by similarity to an ideal solution)模型;然后,将大数据按照得分进行聚类分析,得到了相应的教学特征;最后,将课程考核平均绩点与各项指标得分进行相关分析,结果表明课程综合评价得分以及5项指标与课程成绩均呈现统计学上显著的相关性。
文摘高水平体育赛事已成为体育事业发展的重要助推手段和城市软实力展示的重要媒介,受到了全世界的重视。面对频繁举办的各类体育赛事,其竞争力评价对城市、主办者、参与者都具有重要意义。为科学评价我国体育赛事的竞争力水平,从基础竞争力和核心竞争力两个子系统出发构建马拉松赛事竞争力评价指标体系,采用结构熵权法和均方差决策法进行主客观联合赋权,并以我国13个顶级马拉松赛事为例,完成其竞争力综合评价的实证研究。研究发现:(1)经本研究构建评价指标体系实证所得出的我国顶级马拉松赛事竞争力排序与Ga WC(Globalization and World Cities)组织的世界城市排名结果具有较高匹配度,且这一结果较好契合现状认知,表明该评价指标体系和方法可为其他同类体育赛事竞争力的评价研究提供借鉴。(2)实证中马拉松赛事的基础竞争力与举办城市本身的社会经济实力密切相关,香港、北京、上海和广州等国际一流城市举办的马拉松赛事基础竞争力远远高于衡水等欠发达城市。(3)总体上第三方参度与和赛事水平在马拉松赛事核心竞争力中起着关键作用,台北、厦门、兰州等经济总量不大或中等偏上的城市马拉松赛事的核心竞争力排名比较靠前。(4)我国顶级马拉松赛事的综合竞争力排名从高到低为:香港、北京、广州、台北、上海、杭州、兰州、重庆、厦门、太原、深圳、东营和衡水。(5)我国顶级马拉松赛事竞争力可分为五个等级:香港、北京、广州和上海的马拉松赛事为高水平均衡型;台北和兰州的马拉松赛事为高水平单一型;杭州、重庆、太原和深圳的马拉松赛事为中等水平均衡型;厦门和东营的马拉松赛事为中等水平单一型;衡水马拉松赛事为低水平单一型。等级划分基础上还针对政府、组织者和参与者提出了发展运营、赛事组织、参与选择等方面的对策建议。
