为了提高印制板制造可行性，加快印制板产品设计数据工艺化过程，确保新产品一次投产成功，针对PCB-DFM(Design For Manufacture)设计要求，论述了印制板制造工艺规则功能设计、PRC建模设计及其系统逻辑构成，为整个PCB-CAM系统的设计...为了提高印制板制造可行性，加快印制板产品设计数据工艺化过程，确保新产品一次投产成功，针对PCB-DFM(Design For Manufacture)设计要求，论述了印制板制造工艺规则功能设计、PRC建模设计及其系统逻辑构成，为整个PCB-CAM系统的设计奠定了核心技术基础，制造工艺规则包括了几十种类型的规则，PRC建模设计引入模型概念，提出建模方法，包括模型的范围和语句，系统不但能够基于工艺规则做出可制造性分析，而且能依据某种规则，自动优化工艺设计。展开更多
Flash floods in arid environments are a major hazard feature to human and to the infrastructure. Shortage of accurate environmental data is main reason for inaccurate prediction of flash flooding characteristics. The ...Flash floods in arid environments are a major hazard feature to human and to the infrastructure. Shortage of accurate environmental data is main reason for inaccurate prediction of flash flooding characteristics. The curve number (CN) is a hydrologic number used to describe the storm water runoff potential for drainage area. This study introduces an approach to determine runoff coefficient in Jeddah, Saudi Arabia using remote sensing and GIS. Remote sensing and geographic information system techniques were used to obtain and prepare input data for hydrologic model. The land cover map was derived using maximum likelihood classification of a SPOT image. The soil properties (texture and permeability) were derived using the soil maps published my ministry of water and agriculture in Saudi Arabia. These soil parameters were used to classify the soil map into hydrological soil groups (HSG). Using the derived information within the hydrological modelling system, the runoff depth was predicted for an assumed severe storm scenario. The advantages of the proposed approach are simplicity, less input data, one software used for all steps, and its ability to be applied for any site. The results show that the runoff depth is directly proportional to runoff coefficient and the total volume of runoff is more than 136 million cubic meters for a rainfall of 103.6 mm.展开更多
并网光伏系统通常以最大功率模式运行,无法全面响应电网调节需求,因此需要研究功率备用控制(power reserve control,PRC)。基于最大功率点估计(maximum power point estimation,MPPE)的PRC利用光伏等效模型,通过数据拟合实现MPPE,从而...并网光伏系统通常以最大功率模式运行,无法全面响应电网调节需求,因此需要研究功率备用控制(power reserve control,PRC)。基于最大功率点估计(maximum power point estimation,MPPE)的PRC利用光伏等效模型,通过数据拟合实现MPPE,从而实现光伏功率备用。然而,随着光伏组件老化,MPPE估计误差增大,可能影响系统安全稳定运行。文中提出考虑光伏组件老化时MPPE模型参数校准的光伏系统PRC。首先提出基于麻雀搜索算法的MPPE模型参数校准方法,然后根据光伏组件老化特性和MPPE误差演变趋势,提出MPPE模型校准的改进评价指标和校准周期整定原则,最后将其应用于基于MPPE的PRC中。仿真结果表明,该方法能够实现光伏组件老化后MPPE模型参数自动校准,并且显著提高了MPPE精度,增强了PRC在实际应用中的可靠性。展开更多
This paper introduces a non-Horn rule WRM which is a weak form of rational monotony. We explore the effects of adding this non-Horn rule to the rules for the preferential inference. In this paper, a relation |~ is sai...This paper introduces a non-Horn rule WRM which is a weak form of rational monotony. We explore the effects of adding this non-Horn rule to the rules for the preferential inference. In this paper, a relation |~ is said to be P + WRM iff it is a preferential inference and satisfies the rule WRM. We establish the representation theorem for P + WRM, and compare the strength of WRM with some non-Horn rules appearing in literatures. Moreover, we explore the relation between P + WRM and conditional logic, and demonstrate that P + WRM is equivalent to 'flat' fragment of conditional logic CS4.2. Another contribution of this paper is to explore the relation between two special kinds of preferential models, i.e., PRC model and quasi-linear model. Main result reveals that the latter is a special form of the former.展开更多
文摘为了提高印制板制造可行性，加快印制板产品设计数据工艺化过程，确保新产品一次投产成功，针对PCB-DFM(Design For Manufacture)设计要求，论述了印制板制造工艺规则功能设计、PRC建模设计及其系统逻辑构成，为整个PCB-CAM系统的设计奠定了核心技术基础，制造工艺规则包括了几十种类型的规则，PRC建模设计引入模型概念，提出建模方法，包括模型的范围和语句，系统不但能够基于工艺规则做出可制造性分析，而且能依据某种规则，自动优化工艺设计。
文摘Flash floods in arid environments are a major hazard feature to human and to the infrastructure. Shortage of accurate environmental data is main reason for inaccurate prediction of flash flooding characteristics. The curve number (CN) is a hydrologic number used to describe the storm water runoff potential for drainage area. This study introduces an approach to determine runoff coefficient in Jeddah, Saudi Arabia using remote sensing and GIS. Remote sensing and geographic information system techniques were used to obtain and prepare input data for hydrologic model. The land cover map was derived using maximum likelihood classification of a SPOT image. The soil properties (texture and permeability) were derived using the soil maps published my ministry of water and agriculture in Saudi Arabia. These soil parameters were used to classify the soil map into hydrological soil groups (HSG). Using the derived information within the hydrological modelling system, the runoff depth was predicted for an assumed severe storm scenario. The advantages of the proposed approach are simplicity, less input data, one software used for all steps, and its ability to be applied for any site. The results show that the runoff depth is directly proportional to runoff coefficient and the total volume of runoff is more than 136 million cubic meters for a rainfall of 103.6 mm.
文摘并网光伏系统通常以最大功率模式运行,无法全面响应电网调节需求,因此需要研究功率备用控制(power reserve control,PRC)。基于最大功率点估计(maximum power point estimation,MPPE)的PRC利用光伏等效模型,通过数据拟合实现MPPE,从而实现光伏功率备用。然而,随着光伏组件老化,MPPE估计误差增大,可能影响系统安全稳定运行。文中提出考虑光伏组件老化时MPPE模型参数校准的光伏系统PRC。首先提出基于麻雀搜索算法的MPPE模型参数校准方法,然后根据光伏组件老化特性和MPPE误差演变趋势,提出MPPE模型校准的改进评价指标和校准周期整定原则,最后将其应用于基于MPPE的PRC中。仿真结果表明,该方法能够实现光伏组件老化后MPPE模型参数自动校准,并且显著提高了MPPE精度,增强了PRC在实际应用中的可靠性。
基金the National Natural Science Foundation of China (No.69875007) and the Science Foundation of Jiangsu Province (No.BK99119).
文摘This paper introduces a non-Horn rule WRM which is a weak form of rational monotony. We explore the effects of adding this non-Horn rule to the rules for the preferential inference. In this paper, a relation |~ is said to be P + WRM iff it is a preferential inference and satisfies the rule WRM. We establish the representation theorem for P + WRM, and compare the strength of WRM with some non-Horn rules appearing in literatures. Moreover, we explore the relation between P + WRM and conditional logic, and demonstrate that P + WRM is equivalent to 'flat' fragment of conditional logic CS4.2. Another contribution of this paper is to explore the relation between two special kinds of preferential models, i.e., PRC model and quasi-linear model. Main result reveals that the latter is a special form of the former.
