Arid and semi-arid regions are susceptible to high levels of erosion. A rapid and cost effective methodological erosion assessment for these regions is required to describe and monitor the processes that control erosi...Arid and semi-arid regions are susceptible to high levels of erosion. A rapid and cost effective methodological erosion assessment for these regions is required to describe and monitor the processes that control erosion. This study uses remote sensing to describe the contribution of several factors that control erosion. Topography, land use, vegetation density, soil properties and climatic proxies are used to determine erosion risk and to provide basic maps of water and soil conservation practices. A hierarchical decision tree is used to sum and combine the weight of parameters controlling the erosion. The assigned weights of each spatial unit express the susceptibility to erosion. We focus on the catchment basin of the Maleka Wakena reservoir, located in the southeastern portion of the main Ethiopian Rift, where erosion is the major environmental problem. Three different combinations of the dominant controlling factors are yielded in this study. In order to optimize the qualitative erosion risk assessment, each combination is discussed and evaluated depending on the contribution of parameters involved in the erosion process.展开更多
Task-oriented networked information system is an integrated information system which builds on multi-satellite networking to accomplish one or more tasks. In the background of emer- gency relief for applications, syst...Task-oriented networked information system is an integrated information system which builds on multi-satellite networking to accomplish one or more tasks. In the background of emer- gency relief for applications, system working flow and response process are analyzed, and a timeliness effectiveness evaluation index system is constructed at multi-task level. The effectiveness is a measurement of promptness of information return. In evalua- tion process, system performance and tasks are associated, then an evaluation model based on efficacy function is established, and different evaluation criteria are selected for different tasks. A distributed simulation system is constructed, and the execution of task is decomposed. The simulation platform provides a comprehensive data source for evaluation. The results are easy to compare with each other, which reflects system time efficiency in different satellites networks and provides actual systems with basis and reference for design and application.展开更多
系统利用SQL Server 2000数据库工具和Visual Basic编程语言,开发了具有查询、维护和添加功能的中国枣树害虫信息系统。该系统实现了枣树害虫信息的综合管理,并可按害虫类群、生活环境和地理分布等条件进行快捷的查询,将害虫的分类特征...系统利用SQL Server 2000数据库工具和Visual Basic编程语言,开发了具有查询、维护和添加功能的中国枣树害虫信息系统。该系统实现了枣树害虫信息的综合管理,并可按害虫类群、生活环境和地理分布等条件进行快捷的查询,将害虫的分类特征、生活习性、地理分布、寄主范围等十几项信息以图文并茂的形式直观地展现在用户面前。展开更多
Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptio...Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptions of economical distance of delivery and the best routing algorithm were given on the base of the Dijkstra algorithm with consideration of a coefficient of the road hustle degree. Economical distance of delivery is the shortest physical distance between two customers. It is the value of goods delivery in shortest distance when concerning factors such as the road length, the hustle degree, the driveway quantity, and the type of the road. The improved algorithm is being used in the development and application of a distribution path information system in the terminal distribution of logistics center. The simulation and practical case prove that the algorithm is effective and reasonable.展开更多
文摘Arid and semi-arid regions are susceptible to high levels of erosion. A rapid and cost effective methodological erosion assessment for these regions is required to describe and monitor the processes that control erosion. This study uses remote sensing to describe the contribution of several factors that control erosion. Topography, land use, vegetation density, soil properties and climatic proxies are used to determine erosion risk and to provide basic maps of water and soil conservation practices. A hierarchical decision tree is used to sum and combine the weight of parameters controlling the erosion. The assigned weights of each spatial unit express the susceptibility to erosion. We focus on the catchment basin of the Maleka Wakena reservoir, located in the southeastern portion of the main Ethiopian Rift, where erosion is the major environmental problem. Three different combinations of the dominant controlling factors are yielded in this study. In order to optimize the qualitative erosion risk assessment, each combination is discussed and evaluated depending on the contribution of parameters involved in the erosion process.
基金supported by the National Outstanding Youth Science Foundation(60925011)the Ministerial Key Foundation(9140A170510-10BQ01)China Postdoctoral Science Foundation(20110490033)
文摘Task-oriented networked information system is an integrated information system which builds on multi-satellite networking to accomplish one or more tasks. In the background of emer- gency relief for applications, system working flow and response process are analyzed, and a timeliness effectiveness evaluation index system is constructed at multi-task level. The effectiveness is a measurement of promptness of information return. In evalua- tion process, system performance and tasks are associated, then an evaluation model based on efficacy function is established, and different evaluation criteria are selected for different tasks. A distributed simulation system is constructed, and the execution of task is decomposed. The simulation platform provides a comprehensive data source for evaluation. The results are easy to compare with each other, which reflects system time efficiency in different satellites networks and provides actual systems with basis and reference for design and application.
文摘系统利用SQL Server 2000数据库工具和Visual Basic编程语言,开发了具有查询、维护和添加功能的中国枣树害虫信息系统。该系统实现了枣树害虫信息的综合管理,并可按害虫类群、生活环境和地理分布等条件进行快捷的查询,将害虫的分类特征、生活习性、地理分布、寄主范围等十几项信息以图文并茂的形式直观地展现在用户面前。
基金Social Science Fund of Zhejiang Province(No 06CGGL22YBG)
文摘Dijkstra algorithm is a basic algorithm to analyze the vehicle routing problem (VRP) in the terminal distribution of logistics center. According to the actual client demands of service speed and quality, the conceptions of economical distance of delivery and the best routing algorithm were given on the base of the Dijkstra algorithm with consideration of a coefficient of the road hustle degree. Economical distance of delivery is the shortest physical distance between two customers. It is the value of goods delivery in shortest distance when concerning factors such as the road length, the hustle degree, the driveway quantity, and the type of the road. The improved algorithm is being used in the development and application of a distribution path information system in the terminal distribution of logistics center. The simulation and practical case prove that the algorithm is effective and reasonable.
