The predictability of El Ni-o-Southern Oscillation (ENSO) has been an important area of study for years. Searching for the optimal precursor (OPR) of ENSO occurrence is an effective way to understand its predictabilit...The predictability of El Ni-o-Southern Oscillation (ENSO) has been an important area of study for years. Searching for the optimal precursor (OPR) of ENSO occurrence is an effective way to understand its predictability. The CNOP (conditional nonlinear optimal perturbation), one of the most effective ways to depict the predictability of ENSO, is adopted to study the optimal sea surface temperature (SST) precursors (SST-OPRs) of ENSO in the IOCAS ICM (intermediate coupled model developed at the Institute of Oceanology, Chinese Academy of Sciences). To seek the SST-OPRs of ENSO in the ICM, non-ENSO events simulated by the ICM are chosen as the basic state. Then, the gradient-definition-based method (GD method) is employed to solve the CNOP for different initial months of the basic years to obtain the SSTOPRs. The experimental results show that the obtained SST-OPRs present a positive anomaly signal in the western-central equatorial Pacific, and obvious differences exist in the patterns between the different seasonal SST-OPRs along the equatorial western-central Pacific, showing seasonal dependence to some extent. Furthermore, the non-El Ni-o events can eventually evolve into El Ni-o events when the SST-OPRs are superimposed on the corresponding seasons;the peaks of the Ni-o3.4 index occur at the ends of the years, which is consistent with the evolution of the real El Ni-o. These results show that the GD method is an effective way to obtain SST-OPRs for ENSO events in the ICM. Moreover, the OPRs for ENSO depicted using the GD method provide useful information for finding the early signal of ENSO in the ICM.展开更多
为解决在三维空间状态下零件无法自动标注尺寸的问题,提出一种采用基于模型的定义(Model Based Definition,MBD)技术的零件三维尺寸自动标注方法。首先根据工艺和拓扑相关的表面(Technologically and Topologically Related Surfaces,TT...为解决在三维空间状态下零件无法自动标注尺寸的问题,提出一种采用基于模型的定义(Model Based Definition,MBD)技术的零件三维尺寸自动标注方法。首先根据工艺和拓扑相关的表面(Technologically and Topologically Related Surfaces,TTRS)理论的功能表面分类和边界表示(Boundary Representation,B-Rep)方法,提取出零件的所有拓扑表面,并消除重复多余的表面;然后将提取出的零件表面进行分类,并提取出对应的几何元素;根据其需要标注的定形和定位尺寸制定规则,进而去除冗余元素,构建标注元素集合;最后对CATIA进行二次开发实现零件尺寸的自动标注功能,完成尺寸信息模型的构建。展开更多
为降低配电变压器潜在风险,确保故障风险控制性能,设计基于模型的工程定义(model based definition,MBD)技术的配电变压器潜在故障风险控制系统。使用MBD技术描述系统主电路,根据模块化原则将系统划分为表示层、控制层、业务逻辑层和信...为降低配电变压器潜在风险,确保故障风险控制性能,设计基于模型的工程定义(model based definition,MBD)技术的配电变压器潜在故障风险控制系统。使用MBD技术描述系统主电路,根据模块化原则将系统划分为表示层、控制层、业务逻辑层和信息访问层,运用B/S结构实现系统硬件操作。使用Java开发语言,利用在线监测、风险评价指标、故障风险控制等板块搭建系统软件,引入事故链概念,计算配电变压器失稳及支路过载故障后果,根据核心决策节点,完成潜在故障风险控制。实验结果表明,设计系统具有较好的故障风险控制性能,有效降低配电变压器潜在风险,减小潜在故障风险控制延时。展开更多
为解决MBD技术在航空发动机设计应用中的标准规范不统一和标注信息管理等问题,结合行业特点,制订了独特的通用+典型零部件MBD行业标准,同时,考虑到知识信息表达和多领域应用,提出了基于视图的标注信息(Definition Based Model Views-DB...为解决MBD技术在航空发动机设计应用中的标准规范不统一和标注信息管理等问题,结合行业特点,制订了独特的通用+典型零部件MBD行业标准,同时,考虑到知识信息表达和多领域应用,提出了基于视图的标注信息(Definition Based Model Views-DBMV)管理方法,使得3维MBD模型成为惟一有效的知识信息数据源贯穿应用于产品的全生命周期,成功将MBD技术工程化应用于航空发动机结构设计中。展开更多
随着信息技术、先进制造技术、新材料技术的迅猛发展,航空制造技术正面临着重大的变革,处于产业革命的前夜。数字化协同设计制造技术是航空产业革命的关键技术之一,本文探讨了在大型飞机研制中的基于模型的定义(Model based definition,...随着信息技术、先进制造技术、新材料技术的迅猛发展,航空制造技术正面临着重大的变革,处于产业革命的前夜。数字化协同设计制造技术是航空产业革命的关键技术之一,本文探讨了在大型飞机研制中的基于模型的定义(Model based definition,MBD)技术在数字化协同设计制造中应用的一些方式方法以及存在的问题,提出了比较适合于目前国内航空企业实施MBD的一些思路。展开更多
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. 22120190 207)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA19060102)+4 种基金the National Key Research and Development Program of China (Grant No. 2017YFC1404102(2017YFC1404100))the National Programme on Global Change and Air-Sea Interaction (Grant No. GASIIPOVAI-06)National Natural Science Foundation of China (Grant Nos. 41690122(41690120), 41490644(41490640), 414210 05)the Taishan Scholarshipthe Institute of Oceanology, Chinese Academy of Sciences, for providing technical support for IOCAS ICM
文摘The predictability of El Ni-o-Southern Oscillation (ENSO) has been an important area of study for years. Searching for the optimal precursor (OPR) of ENSO occurrence is an effective way to understand its predictability. The CNOP (conditional nonlinear optimal perturbation), one of the most effective ways to depict the predictability of ENSO, is adopted to study the optimal sea surface temperature (SST) precursors (SST-OPRs) of ENSO in the IOCAS ICM (intermediate coupled model developed at the Institute of Oceanology, Chinese Academy of Sciences). To seek the SST-OPRs of ENSO in the ICM, non-ENSO events simulated by the ICM are chosen as the basic state. Then, the gradient-definition-based method (GD method) is employed to solve the CNOP for different initial months of the basic years to obtain the SSTOPRs. The experimental results show that the obtained SST-OPRs present a positive anomaly signal in the western-central equatorial Pacific, and obvious differences exist in the patterns between the different seasonal SST-OPRs along the equatorial western-central Pacific, showing seasonal dependence to some extent. Furthermore, the non-El Ni-o events can eventually evolve into El Ni-o events when the SST-OPRs are superimposed on the corresponding seasons;the peaks of the Ni-o3.4 index occur at the ends of the years, which is consistent with the evolution of the real El Ni-o. These results show that the GD method is an effective way to obtain SST-OPRs for ENSO events in the ICM. Moreover, the OPRs for ENSO depicted using the GD method provide useful information for finding the early signal of ENSO in the ICM.
文摘为解决在三维空间状态下零件无法自动标注尺寸的问题,提出一种采用基于模型的定义(Model Based Definition,MBD)技术的零件三维尺寸自动标注方法。首先根据工艺和拓扑相关的表面(Technologically and Topologically Related Surfaces,TTRS)理论的功能表面分类和边界表示(Boundary Representation,B-Rep)方法,提取出零件的所有拓扑表面,并消除重复多余的表面;然后将提取出的零件表面进行分类,并提取出对应的几何元素;根据其需要标注的定形和定位尺寸制定规则,进而去除冗余元素,构建标注元素集合;最后对CATIA进行二次开发实现零件尺寸的自动标注功能,完成尺寸信息模型的构建。
文摘为降低配电变压器潜在风险,确保故障风险控制性能,设计基于模型的工程定义(model based definition,MBD)技术的配电变压器潜在故障风险控制系统。使用MBD技术描述系统主电路,根据模块化原则将系统划分为表示层、控制层、业务逻辑层和信息访问层,运用B/S结构实现系统硬件操作。使用Java开发语言,利用在线监测、风险评价指标、故障风险控制等板块搭建系统软件,引入事故链概念,计算配电变压器失稳及支路过载故障后果,根据核心决策节点,完成潜在故障风险控制。实验结果表明,设计系统具有较好的故障风险控制性能,有效降低配电变压器潜在风险,减小潜在故障风险控制延时。
文摘为解决MBD技术在航空发动机设计应用中的标准规范不统一和标注信息管理等问题,结合行业特点,制订了独特的通用+典型零部件MBD行业标准,同时,考虑到知识信息表达和多领域应用,提出了基于视图的标注信息(Definition Based Model Views-DBMV)管理方法,使得3维MBD模型成为惟一有效的知识信息数据源贯穿应用于产品的全生命周期,成功将MBD技术工程化应用于航空发动机结构设计中。
文摘随着信息技术、先进制造技术、新材料技术的迅猛发展,航空制造技术正面临着重大的变革,处于产业革命的前夜。数字化协同设计制造技术是航空产业革命的关键技术之一,本文探讨了在大型飞机研制中的基于模型的定义(Model based definition,MBD)技术在数字化协同设计制造中应用的一些方式方法以及存在的问题,提出了比较适合于目前国内航空企业实施MBD的一些思路。
