Unbalanced energy consumption distribution caused by the concentration of facilities and population topples the natural energy equilibrium of a city and causes environmental problems such as urban tropical night,heat ...Unbalanced energy consumption distribution caused by the concentration of facilities and population topples the natural energy equilibrium of a city and causes environmental problems such as urban tropical night,heat island phenomenon,global warming deterioration.Therefore,to secure eco-friendliness and sustainability of a city,it is necessary to introduce measures to alleviate the unequal distribution phenomenon of urban energy consumption from the city planning stage.For this purpose,the first step is to understand the current energy environment.The urban energy environment is affected by many factors in addition to gathering of buildings.Therefore,there is a limit to fully understanding advanced urban energy environment with only simple statistical urban information management technique.Research on methods of analyzing urban energy environment through simulation of recent urban scale is underway.There is not enough discussion about basic informaion databases for environmental analysis simulation of urban energy.This study presents a method using GIS(geographic information system) and web-based environmental information database as a way to improve the simulation accuracy.First,environmental information factors used for urban simulation were derived,and a web-based environmental information database targeting Daegu metropolitan city of Korea was built.Then,the urban energy environment was analyzed on a trial basis by linking the database with GIS.展开更多
Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, incl...Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, including ACID-compliant, concurrency support, data sharing, and efficient access. Each block model is organized by linear octree, stored in LMDB（lightning memory-mapped database）. Geological attribute can be queried at any point of 3D space by comparison algorithm of location code and conversion algorithm from address code of geometry space to location code of storage. The performance and robustness of querying geological attribute at 3D spatial region are enhanced greatly by the transformation from 3D to 2D and the method of 2D grid scanning to screen the inner and outer points. Experimental results showed that this method can access the massive data of block model, meeting the database characteristics. The method with LMDB is at least 3 times faster than that with etree, especially when it is used to read. In addition, the larger the amount of data is processed, the more efficient the method would be.展开更多
Through field investigation and phenological observation, Microsoft Access database management system is used to establish a relatively comprehensive database of flower border plant materials for Beijing which can pro...Through field investigation and phenological observation, Microsoft Access database management system is used to establish a relatively comprehensive database of flower border plant materials for Beijing which can provide multi-perspective retrieval channels, so as to effectively select materials for designing and building flower borders.展开更多
The paper firstly analyze cache replacement strategies at present, and proposed the ideas of the semantic query cache replacement based on user access features, and describe the semantic similarity calculation and rea...The paper firstly analyze cache replacement strategies at present, and proposed the ideas of the semantic query cache replacement based on user access features, and describe the semantic similarity calculation and realize the algorithm of replacement strategy. The strategy use semantic to match information in the query cache, through dynamic analysis and tracking three characteristics of user access time, user access to content and Business Association, give out the similarity minimum of the cache item, to improve the hit ratio of the cache and the response time and throughput of the server is improved.展开更多
基金Funded by the National Research Foundation of Korea from the Korea government (MEST) under grant No. NRF-2010-0029455
文摘Unbalanced energy consumption distribution caused by the concentration of facilities and population topples the natural energy equilibrium of a city and causes environmental problems such as urban tropical night,heat island phenomenon,global warming deterioration.Therefore,to secure eco-friendliness and sustainability of a city,it is necessary to introduce measures to alleviate the unequal distribution phenomenon of urban energy consumption from the city planning stage.For this purpose,the first step is to understand the current energy environment.The urban energy environment is affected by many factors in addition to gathering of buildings.Therefore,there is a limit to fully understanding advanced urban energy environment with only simple statistical urban information management technique.Research on methods of analyzing urban energy environment through simulation of recent urban scale is underway.There is not enough discussion about basic informaion databases for environmental analysis simulation of urban energy.This study presents a method using GIS(geographic information system) and web-based environmental information database as a way to improve the simulation accuracy.First,environmental information factors used for urban simulation were derived,and a web-based environmental information database targeting Daegu metropolitan city of Korea was built.Then,the urban energy environment was analyzed on a trial basis by linking the database with GIS.
基金Projects(41572317,51374242)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by the Innovation Driven Plan of Central South University,China
文摘Data organization requires high efficiency for large amount of data applied in the digital mine system. A new method of storing massive data of block model is proposed to meet the characteristics of the database, including ACID-compliant, concurrency support, data sharing, and efficient access. Each block model is organized by linear octree, stored in LMDB（lightning memory-mapped database）. Geological attribute can be queried at any point of 3D space by comparison algorithm of location code and conversion algorithm from address code of geometry space to location code of storage. The performance and robustness of querying geological attribute at 3D spatial region are enhanced greatly by the transformation from 3D to 2D and the method of 2D grid scanning to screen the inner and outer points. Experimental results showed that this method can access the massive data of block model, meeting the database characteristics. The method with LMDB is at least 3 times faster than that with etree, especially when it is used to read. In addition, the larger the amount of data is processed, the more efficient the method would be.
文摘Through field investigation and phenological observation, Microsoft Access database management system is used to establish a relatively comprehensive database of flower border plant materials for Beijing which can provide multi-perspective retrieval channels, so as to effectively select materials for designing and building flower borders.
文摘The paper firstly analyze cache replacement strategies at present, and proposed the ideas of the semantic query cache replacement based on user access features, and describe the semantic similarity calculation and realize the algorithm of replacement strategy. The strategy use semantic to match information in the query cache, through dynamic analysis and tracking three characteristics of user access time, user access to content and Business Association, give out the similarity minimum of the cache item, to improve the hit ratio of the cache and the response time and throughput of the server is improved.
