A version of a product consists of the product structure tree and the versions of all its components. The model includes two sets of data： attributes and documents describing each component. The paper discusses the v...A version of a product consists of the product structure tree and the versions of all its components. The model includes two sets of data： attributes and documents describing each component. The paper discusses the version change relations between a sub-node component and a up-node component in a product structure tree, analyzes the version control system for a static reference and that for a dynamic reference and proposes a product structure model in support of dynamic reference, which is easy to use and contains a complete set of information providing an essential way of data organization for the PDM system.展开更多
Southern Malawi is continuously affected by tropical cyclone-related floods(TCRFs),which have negative consequences on households'livelihoods,thereby displacing most households to neighbouring communities of Mozam...Southern Malawi is continuously affected by tropical cyclone-related floods(TCRFs),which have negative consequences on households'livelihoods,thereby displacing most households to neighbouring communities of Mozambique.The TCRFs have further threatened national,regional,community,and household food security agenda,which is already constrained by poverty,poor agricultural practices,low use of improved varieties,unaffordable inorganic fertilizers,and fragmenting landholding sizes.Accordingly,households have indigenously engineered resilience-based Sustainable Landscape Management(SLM)practices,like intercropping,agroforestry,cover cropping,and soil and water conservation practices,against the adverse effects of TCRFs on-farm productivity.Hence,this study examines the effect of TCRFs and SLM adoption on-farm productivity.While using rigorous endogenous switching regression econometric tools,the study finds TCRFs reducing farm productivity by 27 percent.After SLM adoption,the study observes farm productivity enhancement by 29-126 percent when households adopt at least one SLM practices under varying degrees of TCRFs.Despite the highlighted advantages of SLM adoption,female farmers are less likely to adopt SLM practices because they do not have access to productive resources.Hence,the study proposes the need of gender targeted extension services,accompanied by some seed capital for SLM adoption.Besides,there is need to sensitize farmers on the complementarities between inorganic fertilizer and SLM practices.Lastly,future studies should assess the effect of sustained SLM adoption or dis-adoption and input intensification on farm productivity.展开更多
Integration of CAD/CAPP/CAM requires a common product information model with CAD as the key process in forming the model.CAD can not only meet the demands of design, but also meet the demands of the subsystems, such a...Integration of CAD/CAPP/CAM requires a common product information model with CAD as the key process in forming the model.CAD can not only meet the demands of design, but also meet the demands of the subsystems, such as CAPP and CAM.The product modelling system based on STEP (PMSS) uses the 1-DEAS system andadopts STEP as its mechanism to exchange product information.PMSS closely integrates with 1-DEAS and takes advantage of the functions of 1-DEAS to meet the demands of CAD/CAPP/CAM integration. For integration with othersystems, PMSS uses management tool for STEP file to manage information required by subsystems.展开更多
基金Supported by the Fundamental Fujian Nature Science (A0440006) and Xiamen Science & Technology Project (3502Z20055028)
文摘A version of a product consists of the product structure tree and the versions of all its components. The model includes two sets of data： attributes and documents describing each component. The paper discusses the version change relations between a sub-node component and a up-node component in a product structure tree, analyzes the version control system for a static reference and that for a dynamic reference and proposes a product structure model in support of dynamic reference, which is easy to use and contains a complete set of information providing an essential way of data organization for the PDM system.
文摘Southern Malawi is continuously affected by tropical cyclone-related floods(TCRFs),which have negative consequences on households'livelihoods,thereby displacing most households to neighbouring communities of Mozambique.The TCRFs have further threatened national,regional,community,and household food security agenda,which is already constrained by poverty,poor agricultural practices,low use of improved varieties,unaffordable inorganic fertilizers,and fragmenting landholding sizes.Accordingly,households have indigenously engineered resilience-based Sustainable Landscape Management(SLM)practices,like intercropping,agroforestry,cover cropping,and soil and water conservation practices,against the adverse effects of TCRFs on-farm productivity.Hence,this study examines the effect of TCRFs and SLM adoption on-farm productivity.While using rigorous endogenous switching regression econometric tools,the study finds TCRFs reducing farm productivity by 27 percent.After SLM adoption,the study observes farm productivity enhancement by 29-126 percent when households adopt at least one SLM practices under varying degrees of TCRFs.Despite the highlighted advantages of SLM adoption,female farmers are less likely to adopt SLM practices because they do not have access to productive resources.Hence,the study proposes the need of gender targeted extension services,accompanied by some seed capital for SLM adoption.Besides,there is need to sensitize farmers on the complementarities between inorganic fertilizer and SLM practices.Lastly,future studies should assess the effect of sustained SLM adoption or dis-adoption and input intensification on farm productivity.
文摘Integration of CAD/CAPP/CAM requires a common product information model with CAD as the key process in forming the model.CAD can not only meet the demands of design, but also meet the demands of the subsystems, such as CAPP and CAM.The product modelling system based on STEP (PMSS) uses the 1-DEAS system andadopts STEP as its mechanism to exchange product information.PMSS closely integrates with 1-DEAS and takes advantage of the functions of 1-DEAS to meet the demands of CAD/CAPP/CAM integration. For integration with othersystems, PMSS uses management tool for STEP file to manage information required by subsystems.
