On December 26, 2009, in the main control room of Shanghai Fengxian Converter Station, the voltage value on the screen rose from zero to 800 kV. This represented the demonstrative ±800-kV
Based on the experience of environmental acceptance tests for power transmission projects, the problems found in acceptance tests and the system shortcomings of acceptance test itself are analyzed. Recommendations are...Based on the experience of environmental acceptance tests for power transmission projects, the problems found in acceptance tests and the system shortcomings of acceptance test itself are analyzed. Recommendations are provided to improve the future work.展开更多
为提高中国东部区域夏季降水预估的可靠性,利用第六次耦合模式比较计划(Coupled Model Intercomparison Project Phase6,CMIP6)中的全球气候模式以及4个初值大样本的模拟结果,通过“完美模式”可靠性评估框架,对结合模式模拟性能和独立...为提高中国东部区域夏季降水预估的可靠性,利用第六次耦合模式比较计划(Coupled Model Intercomparison Project Phase6,CMIP6)中的全球气候模式以及4个初值大样本的模拟结果,通过“完美模式”可靠性评估框架,对结合模式模拟性能和独立性的加权方案(Climate model Weighting by Independence and Performance,ClimWIP)中的约束变量及其空间尺度进行优选。结果发现将历史时期全球尺度的平均温度趋势作为约束变量比其他更小尺度约束变量得到的加权预估结果更可靠,且综合考虑历史时期全球平均温度趋势和降水指数区域气候态模拟能力约束的ClimWIP方案的预估结果最可靠。基于该最优可靠性的加权预估表明,在SSP5-8.5情景下,相较于历史参考期(1995—2014年),21世纪中期(2041—2060年)和末期(2081—2099年)中国东部区域夏季降水将分别增加6.84%和12.91%,强降水指数增大16.94%和28.66%。其中华北地区增加最为显著,21世纪末期夏季降水和强降水将分别增加19.09%和35.53%。相较于未加权方案(MME),最优预估方案增强了夏季降水的年际变率,未来旱涝的年际变化将更剧烈。同时减小了各区域预估降水的不确定性,并主要集中于预估的高值部分。21世纪中期,东北地区预估不确定性降低最大(40%);末期,华北和长江流域地区预估不确定性降低最大(约50%)。展开更多
In this paper, some test statistics of Kolmogorov type and Cramervon Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high\|dimensional distribution. The limiting d...In this paper, some test statistics of Kolmogorov type and Cramervon Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high\|dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis. The asymptotic properties of Bootstrap approximation are investigated and the tail behaviors of the statistics are studied.展开更多
In this paper, some test statistics of Kolmogorov type and Cramer-von Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high-dimensional distribution. The limiting d...In this paper, some test statistics of Kolmogorov type and Cramer-von Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and any fixed alternative. The asymptotic properties of Bootstrap approximation are investigated.Furthermore, for computational reasons, an approximation for the statistics, based on number theoretic method, is suggested.展开更多
The developmental maturity (M) scale using the Star-Wave Test that was independently developed by Yalon and Zion indicates poor learning abilities if the M-scale score is low, which may be caused by developmental dela...The developmental maturity (M) scale using the Star-Wave Test that was independently developed by Yalon and Zion indicates poor learning abilities if the M-scale score is low, which may be caused by developmental delays, such as intellectual disability and learning disorder or organic mental disorder. Furthermore, the distress (D) scale is thought to be influenced by mild neurological disorders, hand coordination problems, and environmental factors. In this study, we conducted a Star-Wave Test on 44 nursery school children in Japan and examined the M scale, the D scale, as well as the level of stress induced by coordination problems and the environment. The t-test was conducted on the M scale and D scale of the group without coordination problems and that with coordination problems, and we found a significant difference at 1% level. From this result, we can confirm the relationship of the M scale and the D scale with Visual and motor maturity.展开更多
Software testing is a very important phase of the software development process. It is a very difficult job for a software manager to allocate optimally the financial budget to a software project during testing. In thi...Software testing is a very important phase of the software development process. It is a very difficult job for a software manager to allocate optimally the financial budget to a software project during testing. In this paper the problem of optimal allocation of the software testing cost is studied. There exist several models focused on the development of software costs measuring the number of software errors remaining in the software during testing. The purpose of this paper is to use these models to formulate the optimization problems of resource allocation: Minimization of the total number of software errors remaining in the system. On the assumption that a software project consists of some independent modules, the presented approach extends previous work by defining new goal functions and extending the primary assumption and precondition.展开更多
There are many fracture zones crossing the dam foundation of the Xiangjiaba Hydropower Project in southwestern China. Clastic rock is the main media of the fracture zone and has poor physical and mechanical properties...There are many fracture zones crossing the dam foundation of the Xiangjiaba Hydropower Project in southwestern China. Clastic rock is the main media of the fracture zone and has poor physical and mechanical properties. In order to investigate the creep behavior of clastic rock, triaxial creep tests were conducted using a rock servo-controlling rheological testing machine. The results show that the creep behavior of clastic rock is significant at a high level of deviatoric stress, and less time-dependent deformation occurs at high confining pressure. Based on the creep test results, the relationship between axial strain and time under different confining pressures was investigated, and the relationship between axial strain rate and deviatoric stress was also discussed. The strain rate increases rapidly, and the rock sample fails eventually under high deviatoric stress. Moreover, the creep failure mechanism under different confining pressures was analyzed. The main failure mechanism of clastic rock is plastic shear, accompanied by a significant compression and ductile dilatancy. On the other band, with the determined parameters, the Burgers creep model was used to fit the creep curves. The results indicate that the Burgers model can exactly describe the creep behavior of clastic rock in the Xiangjiaba Hydropower Project.展开更多
The in situ shear test and in-lab triaxial shear test on compacted rockfill of Fuling safety embankment were carried out and their advantages and disadvantages were compared. The discreteness of cohesive force C and i...The in situ shear test and in-lab triaxial shear test on compacted rockfill of Fuling safety embankment were carried out and their advantages and disadvantages were compared. The discreteness of cohesive force C and internal frictional angle by in situ shear test is much severer than that by in-lab triaxial shear test. The consolidation of in-lab triaxial shear test is bigger than actual consolidation in rockfill engineerings, so the confining pressure should be reduced to a low level in-lab triaxial shear test.展开更多
文摘On December 26, 2009, in the main control room of Shanghai Fengxian Converter Station, the voltage value on the screen rose from zero to 800 kV. This represented the demonstrative ±800-kV
文摘Based on the experience of environmental acceptance tests for power transmission projects, the problems found in acceptance tests and the system shortcomings of acceptance test itself are analyzed. Recommendations are provided to improve the future work.
文摘为提高中国东部区域夏季降水预估的可靠性,利用第六次耦合模式比较计划(Coupled Model Intercomparison Project Phase6,CMIP6)中的全球气候模式以及4个初值大样本的模拟结果,通过“完美模式”可靠性评估框架,对结合模式模拟性能和独立性的加权方案(Climate model Weighting by Independence and Performance,ClimWIP)中的约束变量及其空间尺度进行优选。结果发现将历史时期全球尺度的平均温度趋势作为约束变量比其他更小尺度约束变量得到的加权预估结果更可靠,且综合考虑历史时期全球平均温度趋势和降水指数区域气候态模拟能力约束的ClimWIP方案的预估结果最可靠。基于该最优可靠性的加权预估表明,在SSP5-8.5情景下,相较于历史参考期(1995—2014年),21世纪中期(2041—2060年)和末期(2081—2099年)中国东部区域夏季降水将分别增加6.84%和12.91%,强降水指数增大16.94%和28.66%。其中华北地区增加最为显著,21世纪末期夏季降水和强降水将分别增加19.09%和35.53%。相较于未加权方案(MME),最优预估方案增强了夏季降水的年际变率,未来旱涝的年际变化将更剧烈。同时减小了各区域预估降水的不确定性,并主要集中于预估的高值部分。21世纪中期,东北地区预估不确定性降低最大(40%);末期,华北和长江流域地区预估不确定性降低最大(约50%)。
文摘In this paper, some test statistics of Kolmogorov type and Cramervon Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high\|dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis. The asymptotic properties of Bootstrap approximation are investigated and the tail behaviors of the statistics are studied.
基金the State Education Commission for ReturnedScholar and the NSF or China.
文摘In this paper, some test statistics of Kolmogorov type and Cramer-von Mises type based on projection pursuit technique are proposed for testing the sphericity problem of a high-dimensional distribution. The limiting distributions of the test statistics are derived under the null hypothesis and any fixed alternative. The asymptotic properties of Bootstrap approximation are investigated.Furthermore, for computational reasons, an approximation for the statistics, based on number theoretic method, is suggested.
文摘The developmental maturity (M) scale using the Star-Wave Test that was independently developed by Yalon and Zion indicates poor learning abilities if the M-scale score is low, which may be caused by developmental delays, such as intellectual disability and learning disorder or organic mental disorder. Furthermore, the distress (D) scale is thought to be influenced by mild neurological disorders, hand coordination problems, and environmental factors. In this study, we conducted a Star-Wave Test on 44 nursery school children in Japan and examined the M scale, the D scale, as well as the level of stress induced by coordination problems and the environment. The t-test was conducted on the M scale and D scale of the group without coordination problems and that with coordination problems, and we found a significant difference at 1% level. From this result, we can confirm the relationship of the M scale and the D scale with Visual and motor maturity.
文摘Software testing is a very important phase of the software development process. It is a very difficult job for a software manager to allocate optimally the financial budget to a software project during testing. In this paper the problem of optimal allocation of the software testing cost is studied. There exist several models focused on the development of software costs measuring the number of software errors remaining in the software during testing. The purpose of this paper is to use these models to formulate the optimization problems of resource allocation: Minimization of the total number of software errors remaining in the system. On the assumption that a software project consists of some independent modules, the presented approach extends previous work by defining new goal functions and extending the primary assumption and precondition.
基金supported by the National Natural Science Foundation of China(Grants No.51409261 and 11172090)the Natural Science Foundation of Shandong Province(Grants No.ZR2014EEQ014)the Applied Basic Research Programs of Qingdao City(Grant No.14-2-4-67-jch)
文摘There are many fracture zones crossing the dam foundation of the Xiangjiaba Hydropower Project in southwestern China. Clastic rock is the main media of the fracture zone and has poor physical and mechanical properties. In order to investigate the creep behavior of clastic rock, triaxial creep tests were conducted using a rock servo-controlling rheological testing machine. The results show that the creep behavior of clastic rock is significant at a high level of deviatoric stress, and less time-dependent deformation occurs at high confining pressure. Based on the creep test results, the relationship between axial strain and time under different confining pressures was investigated, and the relationship between axial strain rate and deviatoric stress was also discussed. The strain rate increases rapidly, and the rock sample fails eventually under high deviatoric stress. Moreover, the creep failure mechanism under different confining pressures was analyzed. The main failure mechanism of clastic rock is plastic shear, accompanied by a significant compression and ductile dilatancy. On the other band, with the determined parameters, the Burgers creep model was used to fit the creep curves. The results indicate that the Burgers model can exactly describe the creep behavior of clastic rock in the Xiangjiaba Hydropower Project.
基金SupportedbyChongqingScienceandTechnologyCommittee (No .2 0 0 1 74 2 9)andWesternCommunicationsProjectofMinistryofCommunications
文摘The in situ shear test and in-lab triaxial shear test on compacted rockfill of Fuling safety embankment were carried out and their advantages and disadvantages were compared. The discreteness of cohesive force C and internal frictional angle by in situ shear test is much severer than that by in-lab triaxial shear test. The consolidation of in-lab triaxial shear test is bigger than actual consolidation in rockfill engineerings, so the confining pressure should be reduced to a low level in-lab triaxial shear test.
