The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributio...The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributions of the critical chloride concentration Cc, the chloride diffusion coefficient D, and the surface chloride concentration Cs were determined based on the collected natural exposure data. And the estimation of probability of corrosion initiation considering the coupling effects of influence factors is presented. It is found that the relative humidity and curing time are the most effective factors affecting the probability of corrosion initiation before and after 10 years of exposure time. At the same exposure time, the influence of load-induced crack and stress state on the probability of corrosion initiation is obvious, in which the effect of crack is the most one展开更多
Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuz...Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuzzy time series forecasting model is built. Inthe new model, a fuzzy clustering algorithm is used to get unequalintervals, and a more objective technique for ascertaining membershipand non-membership functions of the intuitionistic fuzzy setis proposed. On these bases, forecast rules based on multidimensionalintuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature ofBeijing are carried out, which show that the novel model has aclear advantage of improving the forecast accuracy.展开更多
针对南海单点系泊浮式生产储卸油装置(floating production storage and offloading,FPSO),利用水动力分析软件ANSYS AQWA,基于三维势流理论建立其时域耦合分析模型,计算FPSO在正常作业和极端海况下的运动响应及系泊缆张力,分析其在不...针对南海单点系泊浮式生产储卸油装置(floating production storage and offloading,FPSO),利用水动力分析软件ANSYS AQWA,基于三维势流理论建立其时域耦合分析模型,计算FPSO在正常作业和极端海况下的运动响应及系泊缆张力,分析其在不同单缆和双缆组合失效条件下系统的刚度大小、船体运动响应和系泊缆张力,并对系泊系统的安全性能进行量化评估。结果表明:双缆失效对系泊系统纵荡和横荡刚度的降低更加显著,其中船艉同组双缆失效导致系泊纵荡刚度降至最小,舷侧同组双缆系泊失效则使横荡刚度降至最小,两种工况下船体纵荡与横荡更加剧烈,正常作业工况最大纵荡与横荡距离可达25 m和40 m;在十年一遇风浪条件下,单缆断裂后剩余缆绳张力仍可满足安全要求,但同组双缆断裂后,剩余系泊缆张力接近缆绳破断张力,失效风险显著增加;在百年一遇风浪条件下,单缆断裂时满足瞬态破损工况的安全标准,而双缆失效会引发剩余缆绳发生连续破断,最终导致FPSO完全失控。展开更多
基金Project(50925829) supported by the National Science Fund for Distinguished Young Scholars of ChinaProject(50908148) supported by the National Natural Science Foundation of ChinaProjects(2009-K4-23,2010-11-33) supported by the Research of Ministry of Housing and Urban Rural Development of China
文摘The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributions of the critical chloride concentration Cc, the chloride diffusion coefficient D, and the surface chloride concentration Cs were determined based on the collected natural exposure data. And the estimation of probability of corrosion initiation considering the coupling effects of influence factors is presented. It is found that the relative humidity and curing time are the most effective factors affecting the probability of corrosion initiation before and after 10 years of exposure time. At the same exposure time, the influence of load-induced crack and stress state on the probability of corrosion initiation is obvious, in which the effect of crack is the most one
基金supported by the National Natural Science Foundation of China(61309022)
文摘Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuzzy time series forecasting model is built. Inthe new model, a fuzzy clustering algorithm is used to get unequalintervals, and a more objective technique for ascertaining membershipand non-membership functions of the intuitionistic fuzzy setis proposed. On these bases, forecast rules based on multidimensionalintuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature ofBeijing are carried out, which show that the novel model has aclear advantage of improving the forecast accuracy.
文摘针对南海单点系泊浮式生产储卸油装置(floating production storage and offloading,FPSO),利用水动力分析软件ANSYS AQWA,基于三维势流理论建立其时域耦合分析模型,计算FPSO在正常作业和极端海况下的运动响应及系泊缆张力,分析其在不同单缆和双缆组合失效条件下系统的刚度大小、船体运动响应和系泊缆张力,并对系泊系统的安全性能进行量化评估。结果表明:双缆失效对系泊系统纵荡和横荡刚度的降低更加显著,其中船艉同组双缆失效导致系泊纵荡刚度降至最小,舷侧同组双缆系泊失效则使横荡刚度降至最小,两种工况下船体纵荡与横荡更加剧烈,正常作业工况最大纵荡与横荡距离可达25 m和40 m;在十年一遇风浪条件下,单缆断裂后剩余缆绳张力仍可满足安全要求,但同组双缆断裂后,剩余系泊缆张力接近缆绳破断张力,失效风险显著增加;在百年一遇风浪条件下,单缆断裂时满足瞬态破损工况的安全标准,而双缆失效会引发剩余缆绳发生连续破断,最终导致FPSO完全失控。
文摘碳价是碳市场的核心要素,碳价波动受到众多因素及其时滞效应的影响。为精准预测全国碳市场碳排放配额(Chinese emission allowances,CEA)价格,从关联碳市场、经济发展、国外能源、国内能源和人民币汇率五个维度选取结构化影响因素,从经济政策、环境影响和用户意愿三个维度爬取来自百度搜索引擎的非结构化影响因素,然后引入MIV-BP模型筛选主要的影响因素,并基于最大信息系数(maximum information coefficient,MIC)对碳价以及多源影响因素进行时滞估计。在此基础上,构建融合多源信息的碳价时滞组合预测模型MIC-LSTM-BP,并和基准模型LSTM、BP、LSTM-BP以及时滞基准模型MIC-LSTM、MIC-BP、MIC-LSTM-GBDT进行对比分析,以验证新模型的有效性。结果表明,时滞信息的引入有助于提升模型的预测精度;相较于基准模型和时滞基准模型,MICLSTM-BP模型预测CEA价格精度最高,价格波动追随能力最好。
