The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the...The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the mould design process, in addition to the material and geometry of the part. A framed-mould computer-aided design system （FMCAD） used in the autoclave moulding process is proposed in this paper. A function model of the software is presented, in which influence factors such as part structure, mould structure, and process parameters are considered; a design model of the software is established using object oriented （O-O） technology to integrate the stiffness calculation, temperature field calculation, and deformation field calculation of mould in the design, and in the design model, a hybrid model of mould based on calculation feature and form feature is presented to support those calculations. A prototype system is developed, in which a mould design process wizard is built to integrate the input information, calculation, analysis, data storage, display, and design results of mould design. Finally, three design examples are used to verify the prototype.展开更多
Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these i...Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these instabilities is well known as “shark-skin” which damages the surface appearance and properties of polymer extrudate while processing in blowmolding or piping, while it can be suppressed by employing various methods including coating the die surface and/or adding Polymer Processing Aid’s (PPA) to the polymer. In this article, the effect of various die materials on the properties of Polyethylene glycol (PEG) as a new type of PPA for suppressing the sharkskin phenomenon has been studied.展开更多
This paper presents a software developed for the computer aided die forging process planning expert system, an expert knowledge base built in an appropriate knowledge representation form in accordance with special fe...This paper presents a software developed for the computer aided die forging process planning expert system, an expert knowledge base built in an appropriate knowledge representation form in accordance with special features of die forging technology, an inference engine combining procedural reasoning with backward reasoning by means of a blackboard to satisfy the multi level and multi goal requirements for the system, and maintenance of the system in the way of semi automatic knowledge acquisition.展开更多
A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, ag...A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, agent oriented programming language, knowledge representation and reasoning strategy. The system can produce the technological file and technological quota, which can satisfy the production needs of factory.展开更多
Computer aided process planning system played a key role for integrating design and manufacturing or assembly systems properly considering available resources and design constraints.To take advantage of the enterprise...Computer aided process planning system played a key role for integrating design and manufacturing or assembly systems properly considering available resources and design constraints.To take advantage of the enterprise resource,the web CAPP framework was established.Case based reasoning and multi agent system were integrated in the system.The multi agent mecha-nism was discussed in the paper.And an instance of case base was introduced.They made the system run independently and contin-uously in the network environment of process planning problems.展开更多
Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r ...Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r Aided Process Planning (CAPP) is a step in this direction. Most of the existin g CAPP systems do not consider scheduling while generating a process plan. Sched uling is done separately after the process plan has been generated and therefore , it is possible that a process plan so generated is either not optimal or feasi ble from scheduling point of view. As process plans are generated without consid eration of job shop status, many problems arise within the manufacturing environ ment. Investigations have shown that 20%～30% of all process plans generated are not valid and have to be altered or suffer production delays when production sta rts. There is thus a major need for integration of scheduling with computer aide d process planning for generating more realistic process plans. In doing so, eff iciency of the manufacturing system as a whole is expected to improve. Decision support system performs many functions such as selection of machine too ls, cutting tools, sequencing of operations, determination of optimum cutting pa rameters and checking availability of machine tool before allocating any operati on to a machine tool. The process of transforming component data, process capabi lity and decision rules into computer readable format is still a major obstacle. This paper proposes architecture of a system, which integrates computer aided p rocess-planning system with scheduling using decision support system. A decisio n support system can be defined as " an interactive system that provides the use rs with easy access to decision models in order to support semi-structured or u nstructured decision making tasks".展开更多
Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at th...Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at the national and regional levels, and to explain the obstacles of policy implementation. The method was qualitative study. The stakeholders were 88 people. The data were collected by in-depth interview and coded by a computer program. The policy was transferred from the national AIDS committee to the Department of Disease Control （DDC） and provincial level. This process was lacking budget support. The provincial AIDS committee was monitored by the provincial health office, cooperating with the central level. The major role was to transfer the policy to the school, Local Administration Organization （LAO） and associated organization. The activity was funded by provincial, global funds, and outside sources. In the community, the core activities were AIDS knowledge, establishing core youth groups, and building the network of AIDS. The obstacle at the national level was changing the policy process from one with a budget to one without budget. In the area of practice, the AIDS problem and the effects of the risk behavior in youth groups were slightly concerned.展开更多
This paper presents a new spline called arc spline.It takes two arcsconnecting adjacent points among a sampled series,with known tangental of eachsampled point.The calculation for the parallel.the curve length and the...This paper presents a new spline called arc spline.It takes two arcsconnecting adjacent points among a sampled series,with known tangental of eachsampled point.The calculation for the parallel.the curve length and the segment-ing point coordinates are simple,thus making map symbol generation simplified.When 'arclet' occurs,some special processing must be taken.展开更多
In order to reduce the development cycle of mechanical products and corresponding toolings, a large number of components are utilized in these structures. Accordingly, automatic location method for components is a key...In order to reduce the development cycle of mechanical products and corresponding toolings, a large number of components are utilized in these structures. Accordingly, automatic location method for components is a key issue in the research on intelligent computer aided design （CAD） techniques. Integrated with the investigation into intelligent design techniques for aircraft manufacturing toolings, in-depth researches on this issue are conducted. Formalized automatic location principles, representative methods and implementation algorithms are proposed and established. First, several terms and their formalized representative methods including process condition, location base and location operator are defined. Second, computation modeling of components automatic location and methods of location transformation are proposed. Then, definition of base structure and some key algorithms for automatic location are introduced. These principles and algorithms are developed, applied and verified in research project ＂Jig Intelligent CAD （JiglCAD） System＂.展开更多
Machining process data is the core of computer aided process planning application systems.It is also provides essen-tial content for product life cycle engineering.The character of CAPP that supports product LCE and v...Machining process data is the core of computer aided process planning application systems.It is also provides essen-tial content for product life cycle engineering.The character of CAPP that supports product LCE and virtual manufacturing is an-alyzed.The structure and content of machining process data concerning green manufacturing is also examined.A logic model of Machining Process Data has been built based on an object oriented approach,using UML technology and a physical model of machin-ing process data that utilizes XML technology.To realize the integration of design and process,an approach based on graph-based volume decomposition was apposed.Instead,to solve the problem of generation in the machining process,case-based reasoning and rule-based reasoning have been applied synthetically.Finally,the integration framework and interface that deal with the CAPP integration with CAD,CAM,PDM,and ERP are discussed.展开更多
文摘The general computer-aided design （CAD） software cannot meet the mould design requirement of the autoclave process for composites, because many parameters such as temperature and pressure should be considered in the mould design process, in addition to the material and geometry of the part. A framed-mould computer-aided design system （FMCAD） used in the autoclave moulding process is proposed in this paper. A function model of the software is presented, in which influence factors such as part structure, mould structure, and process parameters are considered; a design model of the software is established using object oriented （O-O） technology to integrate the stiffness calculation, temperature field calculation, and deformation field calculation of mould in the design, and in the design model, a hybrid model of mould based on calculation feature and form feature is presented to support those calculations. A prototype system is developed, in which a mould design process wizard is built to integrate the input information, calculation, analysis, data storage, display, and design results of mould design. Finally, three design examples are used to verify the prototype.
文摘Flows of polymeric liquids undergo instabilities whose origins are quite different from those of Newtonian flows, due to their elastic character and the complexity of the fluid/solid boundary condition. One of these instabilities is well known as “shark-skin” which damages the surface appearance and properties of polymer extrudate while processing in blowmolding or piping, while it can be suppressed by employing various methods including coating the die surface and/or adding Polymer Processing Aid’s (PPA) to the polymer. In this article, the effect of various die materials on the properties of Polyethylene glycol (PEG) as a new type of PPA for suppressing the sharkskin phenomenon has been studied.
文摘This paper presents a software developed for the computer aided die forging process planning expert system, an expert knowledge base built in an appropriate knowledge representation form in accordance with special features of die forging technology, an inference engine combining procedural reasoning with backward reasoning by means of a blackboard to satisfy the multi level and multi goal requirements for the system, and maintenance of the system in the way of semi automatic knowledge acquisition.
文摘A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, agent oriented programming language, knowledge representation and reasoning strategy. The system can produce the technological file and technological quota, which can satisfy the production needs of factory.
文摘Computer aided process planning system played a key role for integrating design and manufacturing or assembly systems properly considering available resources and design constraints.To take advantage of the enterprise resource,the web CAPP framework was established.Case based reasoning and multi agent system were integrated in the system.The multi agent mecha-nism was discussed in the paper.And an instance of case base was introduced.They made the system run independently and contin-uously in the network environment of process planning problems.
文摘Process planning and scheduling are two major plann in g and control activities that consume significant part of the lead-time, theref ore all attempts are being made to reduce lead-time by automating them. Compute r Aided Process Planning (CAPP) is a step in this direction. Most of the existin g CAPP systems do not consider scheduling while generating a process plan. Sched uling is done separately after the process plan has been generated and therefore , it is possible that a process plan so generated is either not optimal or feasi ble from scheduling point of view. As process plans are generated without consid eration of job shop status, many problems arise within the manufacturing environ ment. Investigations have shown that 20%～30% of all process plans generated are not valid and have to be altered or suffer production delays when production sta rts. There is thus a major need for integration of scheduling with computer aide d process planning for generating more realistic process plans. In doing so, eff iciency of the manufacturing system as a whole is expected to improve. Decision support system performs many functions such as selection of machine too ls, cutting tools, sequencing of operations, determination of optimum cutting pa rameters and checking availability of machine tool before allocating any operati on to a machine tool. The process of transforming component data, process capabi lity and decision rules into computer readable format is still a major obstacle. This paper proposes architecture of a system, which integrates computer aided p rocess-planning system with scheduling using decision support system. A decisio n support system can be defined as " an interactive system that provides the use rs with easy access to decision models in order to support semi-structured or u nstructured decision making tasks".
文摘Thailand was implementing the policy of HIV/A1DS prevention in risky group, The youth is one of groups with sexual risk behaviors to HIV/AIDS. This research aims to elucidate the process of policy implementation at the national and regional levels, and to explain the obstacles of policy implementation. The method was qualitative study. The stakeholders were 88 people. The data were collected by in-depth interview and coded by a computer program. The policy was transferred from the national AIDS committee to the Department of Disease Control （DDC） and provincial level. This process was lacking budget support. The provincial AIDS committee was monitored by the provincial health office, cooperating with the central level. The major role was to transfer the policy to the school, Local Administration Organization （LAO） and associated organization. The activity was funded by provincial, global funds, and outside sources. In the community, the core activities were AIDS knowledge, establishing core youth groups, and building the network of AIDS. The obstacle at the national level was changing the policy process from one with a budget to one without budget. In the area of practice, the AIDS problem and the effects of the risk behavior in youth groups were slightly concerned.
文摘This paper presents a new spline called arc spline.It takes two arcsconnecting adjacent points among a sampled series,with known tangental of eachsampled point.The calculation for the parallel.the curve length and the segment-ing point coordinates are simple,thus making map symbol generation simplified.When 'arclet' occurs,some special processing must be taken.
基金National High-tech Research and Development Program of China (2007AA041902)
文摘In order to reduce the development cycle of mechanical products and corresponding toolings, a large number of components are utilized in these structures. Accordingly, automatic location method for components is a key issue in the research on intelligent computer aided design （CAD） techniques. Integrated with the investigation into intelligent design techniques for aircraft manufacturing toolings, in-depth researches on this issue are conducted. Formalized automatic location principles, representative methods and implementation algorithms are proposed and established. First, several terms and their formalized representative methods including process condition, location base and location operator are defined. Second, computation modeling of components automatic location and methods of location transformation are proposed. Then, definition of base structure and some key algorithms for automatic location are introduced. These principles and algorithms are developed, applied and verified in research project ＂Jig Intelligent CAD （JiglCAD） System＂.
文摘Machining process data is the core of computer aided process planning application systems.It is also provides essen-tial content for product life cycle engineering.The character of CAPP that supports product LCE and virtual manufacturing is an-alyzed.The structure and content of machining process data concerning green manufacturing is also examined.A logic model of Machining Process Data has been built based on an object oriented approach,using UML technology and a physical model of machin-ing process data that utilizes XML technology.To realize the integration of design and process,an approach based on graph-based volume decomposition was apposed.Instead,to solve the problem of generation in the machining process,case-based reasoning and rule-based reasoning have been applied synthetically.Finally,the integration framework and interface that deal with the CAPP integration with CAD,CAM,PDM,and ERP are discussed.
