Gas extraction is one of the main measures of control and use of gas of coal mines. At present, the design method is under the experimental period and do not satisfy the need of practice. In this paper, the theory of ...Gas extraction is one of the main measures of control and use of gas of coal mines. At present, the design method is under the experimental period and do not satisfy the need of practice. In this paper, the theory of gas extraction of coal seams based upon Darcy law was studied. Mathematical model of gas extraction of coal seams was established and two kinds of solv- ing approaches based on computer software and linear approximation were given. The rightness and the validities of the model were examined with a practical example. Results obtained can be used to determine and optimize the parameters related etc.展开更多
This paper addresses the need for systematic evaluation of the station keeping systems of deepwater drilling semi-submersibles.Based on the selected drilling semi-submersible configuration, the mooring systems were an...This paper addresses the need for systematic evaluation of the station keeping systems of deepwater drilling semi-submersibles.Based on the selected drilling semi-submersible configuration, the mooring systems were analyzed and designed for a range of water depths using different mooring line materials.These were steel wire rope, polyester rope and HMPE (high modulus poly ethylene).The mooring analysis was carried out using the advanced fully coupled time domain analysis method in the computer software package HARP.Diffraction analysis was first applied to solve the hydrodynamic properties of the vessel and then the motion equations of the complete dynamic system including the drilling rig, the mooring lines and risers were developed and solved in the time domain.Applying the advanced analysis method, a matrix of mooring systems was developed for operating in water depths of 1000 m, 1500 m, and 2 000 m using various mooring materials.The development of mooring systems was conducted in accordance with the commonly adopted mooring design code, API RP 2SK and API RP 2SM.Fresh attempts were then made to comparatively evaluate the mooring system's characteristics and global performance.Useful results have been obtained in terms of mooring materials, water depths, and key parameters of mooring configurations.The results provide in-depth insight for the design and operation of deepwater mooring systems in the South China Sea environment.展开更多
A pattern is used to describe best practices and principles. Patterns have been used successfully in architecture and in software design. We propose to apply the pattern method to XML-based security engineering. Organ...A pattern is used to describe best practices and principles. Patterns have been used successfully in architecture and in software design. We propose to apply the pattern method to XML-based security engineering. Organized collections of interrelated patterns (called pattern languages) can embody whole bodies of knowledge on specific topics. We will discuss patterns and security pattern, pattern languages and the requirements of the pattern languages proposing its essential requirement (the template), and lays the groundwork for our future development of a true XML-based security pattern language.展开更多
The scope of the paper is the design of a fluid machinery with a multiphysics procedure, through CAD （computer-aided design）-CAE （computer-aided engineering）-CAx （computer-aided technologies） tools. The study of...The scope of the paper is the design of a fluid machinery with a multiphysics procedure, through CAD （computer-aided design）-CAE （computer-aided engineering）-CAx （computer-aided technologies） tools. The study of a wind turbine is a perfect example of a project that requires an interdisciplinary team design, in fact for such a project mechanical structure, and CFD （computational fluid dynamics） designers are necessary. In addition, in the last years, the multi domain design has been supported by the continuous development of software for computer-aided design and the unceasing increase of the connection between performances and computer costs： the final aim is to propose the instruments that assist the designer throughout all the steps of the project. The multi domain design, illustrated in this article, is based on how to design the wind turbine, and it is not about process management and manufacturability. In particular, in the article, the emphasis will be placed on the integration between CAD and mathematical software of general type and on the CAD-CAE integration.展开更多
This paper, starting from the actual situation of students and computer software teaching status of art design major, combined with the teaching practical experience of the major, summarizes the idea of computer softw...This paper, starting from the actual situation of students and computer software teaching status of art design major, combined with the teaching practical experience of the major, summarizes the idea of computer software teaching reform in art design and the specific measures of improving teaching methods and teaching means and guides the teaching practice, realizing the guidance and inspection of theory for practice, in order to bring inspiration and help for the art teaching in the future.展开更多
Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how ...Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how to estimate the reusability of test conlponents for automated testing. The purpose of this paper is to present a method of minimum reusability estimation for automated testing based on the return on investment （ROI） model. Minimum reusability is a benchmark for the whole automated testing process. If the reusability in one test execution is less than the minimum reusability, some new strategies must be adopted ill the next test execution to increase the reusability. Only by this way, we can reduce unnecessary costs and finally get a return on the investment of automated testing.展开更多
文摘Gas extraction is one of the main measures of control and use of gas of coal mines. At present, the design method is under the experimental period and do not satisfy the need of practice. In this paper, the theory of gas extraction of coal seams based upon Darcy law was studied. Mathematical model of gas extraction of coal seams was established and two kinds of solv- ing approaches based on computer software and linear approximation were given. The rightness and the validities of the model were examined with a practical example. Results obtained can be used to determine and optimize the parameters related etc.
基金Supported by China National 111 Project under Grant No.B07019
文摘This paper addresses the need for systematic evaluation of the station keeping systems of deepwater drilling semi-submersibles.Based on the selected drilling semi-submersible configuration, the mooring systems were analyzed and designed for a range of water depths using different mooring line materials.These were steel wire rope, polyester rope and HMPE (high modulus poly ethylene).The mooring analysis was carried out using the advanced fully coupled time domain analysis method in the computer software package HARP.Diffraction analysis was first applied to solve the hydrodynamic properties of the vessel and then the motion equations of the complete dynamic system including the drilling rig, the mooring lines and risers were developed and solved in the time domain.Applying the advanced analysis method, a matrix of mooring systems was developed for operating in water depths of 1000 m, 1500 m, and 2 000 m using various mooring materials.The development of mooring systems was conducted in accordance with the commonly adopted mooring design code, API RP 2SK and API RP 2SM.Fresh attempts were then made to comparatively evaluate the mooring system's characteristics and global performance.Useful results have been obtained in terms of mooring materials, water depths, and key parameters of mooring configurations.The results provide in-depth insight for the design and operation of deepwater mooring systems in the South China Sea environment.
基金"China National Science Foundation"under grant No: 2001AA412010
文摘A pattern is used to describe best practices and principles. Patterns have been used successfully in architecture and in software design. We propose to apply the pattern method to XML-based security engineering. Organized collections of interrelated patterns (called pattern languages) can embody whole bodies of knowledge on specific topics. We will discuss patterns and security pattern, pattern languages and the requirements of the pattern languages proposing its essential requirement (the template), and lays the groundwork for our future development of a true XML-based security pattern language.
文摘The scope of the paper is the design of a fluid machinery with a multiphysics procedure, through CAD （computer-aided design）-CAE （computer-aided engineering）-CAx （computer-aided technologies） tools. The study of a wind turbine is a perfect example of a project that requires an interdisciplinary team design, in fact for such a project mechanical structure, and CFD （computational fluid dynamics） designers are necessary. In addition, in the last years, the multi domain design has been supported by the continuous development of software for computer-aided design and the unceasing increase of the connection between performances and computer costs： the final aim is to propose the instruments that assist the designer throughout all the steps of the project. The multi domain design, illustrated in this article, is based on how to design the wind turbine, and it is not about process management and manufacturability. In particular, in the article, the emphasis will be placed on the integration between CAD and mathematical software of general type and on the CAD-CAE integration.
文摘This paper, starting from the actual situation of students and computer software teaching status of art design major, combined with the teaching practical experience of the major, summarizes the idea of computer software teaching reform in art design and the specific measures of improving teaching methods and teaching means and guides the teaching practice, realizing the guidance and inspection of theory for practice, in order to bring inspiration and help for the art teaching in the future.
基金Foundation item： the National Natural Science Foundation of China （No. 90718037）
文摘Through reusing software test components, automated software testing generally costs less than manual software testing. There has been much research on how to develop the reusable test components, but few fall on how to estimate the reusability of test conlponents for automated testing. The purpose of this paper is to present a method of minimum reusability estimation for automated testing based on the return on investment （ROI） model. Minimum reusability is a benchmark for the whole automated testing process. If the reusability in one test execution is less than the minimum reusability, some new strategies must be adopted ill the next test execution to increase the reusability. Only by this way, we can reduce unnecessary costs and finally get a return on the investment of automated testing.
