In this paper,applications of CWC-mappings are discussed in metrization theorem, and some new metrization theorems of topological spaces are obtained by Nagata's condition and weakγ-spaces,which generalizes sever...In this paper,applications of CWC-mappings are discussed in metrization theorem, and some new metrization theorems of topological spaces are obtained by Nagata's condition and weakγ-spaces,which generalizes several metrization theorems obtained by R.E.Hodel and J.Nagata.展开更多
The Reynolds-averaged Navier–Stokes(RANS)equation was solved using computational fluid dynamics to study the effect of the circulating tank wall on the hydrodynamic coefficient of an autonomous underwater vehicle(AUV...The Reynolds-averaged Navier–Stokes(RANS)equation was solved using computational fluid dynamics to study the effect of the circulating tank wall on the hydrodynamic coefficient of an autonomous underwater vehicle(AUV).Numerical results were compared with the experimental results in the circulating water tank of Harbin Engineering University.The numerical results of the model with different scale ratios under the same water in the flume were studied to investigate the effect of blockage on the hydrodynamic performance of AUV in the circulating flume model test.The results show that the hydrodynamic coefficient is stable with the scale reduction of the model.The influence of blocking effect on AUV is given by combining theoretical calculation with experiment.展开更多
There is growing needs for web based GIS for easy and fast dissemination, sharing, displaying and processing of spatial information which in turns helping in decision making for various natural resources based applica...There is growing needs for web based GIS for easy and fast dissemination, sharing, displaying and processing of spatial information which in turns helping in decision making for various natural resources based applications. In order to make a cost effective implementation, operation and maintenance of spatial information over the web, a cheaper yet feature rich alternative to commercial software is required which can be fulfilled by Open Source GIS software. This paper conveys an efficient approach to customize and integrate an open source web GIS system based on Mapserver as a web GIS server and PostgreSQL/PostGIS as an object oriented relational database management system (ORDBMS) for effective dissemination, sharing and management of spatial information over the internet. An open source web application tool built on top of MapScript using the PHP programming language has been used as for development of interactive user interface. The configurable Web Mapping Client Components (CWC2) tags have been added to HTML template pages in order to deploy the mapping contents to a web application. It is observed that the present system developed using open source software enables user to view, update, customized retrieval, query and analysis of natural resources information for specific needs.展开更多
基金the National Natural Science Foundation of China （No. 10571151） the Natural Science Foundation of Fujian Province （No. 2006J0228） the Natural Science Foundation of Education Department of Fujian Province （No. JB04298）.Acknowledgment The author is very grateful to Professor Lin Shou for his help and the referee for his valuable suggestions.
文摘In this paper,applications of CWC-mappings are discussed in metrization theorem, and some new metrization theorems of topological spaces are obtained by Nagata's condition and weakγ-spaces,which generalizes several metrization theorems obtained by R.E.Hodel and J.Nagata.
基金Supported by the National Natural Science Foundation of China(Grant No.51909040)the Fund of Science and Technology on Underwater Vehicle Technology(Grant No.JCKYS2022SXJQR-11)+1 种基金the Heilongjiang Provincial Natural Science Foundation of China(Grant No.LH2020E073)the Key Technology Research and Development Program of Shandong(Grant No.2020CXGC010702).
文摘The Reynolds-averaged Navier–Stokes(RANS)equation was solved using computational fluid dynamics to study the effect of the circulating tank wall on the hydrodynamic coefficient of an autonomous underwater vehicle(AUV).Numerical results were compared with the experimental results in the circulating water tank of Harbin Engineering University.The numerical results of the model with different scale ratios under the same water in the flume were studied to investigate the effect of blockage on the hydrodynamic performance of AUV in the circulating flume model test.The results show that the hydrodynamic coefficient is stable with the scale reduction of the model.The influence of blocking effect on AUV is given by combining theoretical calculation with experiment.
文摘There is growing needs for web based GIS for easy and fast dissemination, sharing, displaying and processing of spatial information which in turns helping in decision making for various natural resources based applications. In order to make a cost effective implementation, operation and maintenance of spatial information over the web, a cheaper yet feature rich alternative to commercial software is required which can be fulfilled by Open Source GIS software. This paper conveys an efficient approach to customize and integrate an open source web GIS system based on Mapserver as a web GIS server and PostgreSQL/PostGIS as an object oriented relational database management system (ORDBMS) for effective dissemination, sharing and management of spatial information over the internet. An open source web application tool built on top of MapScript using the PHP programming language has been used as for development of interactive user interface. The configurable Web Mapping Client Components (CWC2) tags have been added to HTML template pages in order to deploy the mapping contents to a web application. It is observed that the present system developed using open source software enables user to view, update, customized retrieval, query and analysis of natural resources information for specific needs.
