The uncertainty of the mechanism motion error is mostly caused by the manufacturing process,so the motion error cannot be effectively predicted at the design phase.The problems of manufacturing complexity and the rela...The uncertainty of the mechanism motion error is mostly caused by the manufacturing process,so the motion error cannot be effectively predicted at the design phase.The problems of manufacturing complexity and the relationship between design and manufacturing are analyzed,and the influence of dimensional tolerance and fit tolerance on the motion accuracy of the system is considered in the design process.Then based on the Monte Carlo simulation,an optimal design model of planar linkage mechanism is set up.A typical offset slider-crank mechanism is used as an illustrative example to carry out the optimal design.Compared with the result of typical robustness design,the similar variation characteristics of the mean value and the standard deviation can be found,so the proposed method is effective.The method is furthermore applied in the optimization of the schemes with different fit tolerances and the prediction of motion errors in the design phase is achieved.A set of quantitative evaluation system for mechanism optimal design is provided.Finally,a basic strategy is presented to balance the motion precision and manufacturing cost.展开更多
Key project of " manufacturing industry and logistics industry linkage"was proposed in the Logistics Adjustment and Revitalization Plan by the state council in 2009. However the consumption and pollution gen...Key project of " manufacturing industry and logistics industry linkage"was proposed in the Logistics Adjustment and Revitalization Plan by the state council in 2009. However the consumption and pollution generated by manufacturing industry and logistics industry linkage in China are also large at present. How to conduct manufacturing industry and logistics industry linkage by the low-carbon manner is one of most important issues under current low-carbon economy background. In this paper,the issue is studied and analyzed by constructing system dynamics model,which could propose suggestions for low-carbon linkage development of manufacturing industry and logistics industry.展开更多
As innovation and technological change have become increasingly important for the competitiveness and sustainable growth of firms,cooperative innovation is now crucial for traditional industries in the context of glob...As innovation and technological change have become increasingly important for the competitiveness and sustainable growth of firms,cooperative innovation is now crucial for traditional industries in the context of globalization.This paper proposes a framework for analyzing the spatial pattern of cooperative innovation for traditional industries in developing countries.Based on in-depth interviews with 35 firms in the oil equipment manufacturing industry in Dongying City,China,this study argues that different firms in the innovation pyramid have various innovation activity preferences and spatial patterns.Firms with high innovation abilities tend to cooperate with various partners that are geographically dispersed and continuously expanding,while firms with inferior abilities usually cooperate with nearby fixed partners.Due to the differences in innovation environment and actor locations,firms tend to make different choices regarding innovation types and models,which highlight the importance of personnel training and basic scientific research at the global scale and practical product research and development at the national scale.Additionally,talent flow is the most important way to realize relationships for firm innovation activity.展开更多
基金supported by the National Natural Science Foundation of China(No.51275365)the National High-tech R&D Program (863 Program ) (No. 2014AA041504)
文摘The uncertainty of the mechanism motion error is mostly caused by the manufacturing process,so the motion error cannot be effectively predicted at the design phase.The problems of manufacturing complexity and the relationship between design and manufacturing are analyzed,and the influence of dimensional tolerance and fit tolerance on the motion accuracy of the system is considered in the design process.Then based on the Monte Carlo simulation,an optimal design model of planar linkage mechanism is set up.A typical offset slider-crank mechanism is used as an illustrative example to carry out the optimal design.Compared with the result of typical robustness design,the similar variation characteristics of the mean value and the standard deviation can be found,so the proposed method is effective.The method is furthermore applied in the optimization of the schemes with different fit tolerances and the prediction of motion errors in the design phase is achieved.A set of quantitative evaluation system for mechanism optimal design is provided.Finally,a basic strategy is presented to balance the motion precision and manufacturing cost.
文摘Key project of " manufacturing industry and logistics industry linkage"was proposed in the Logistics Adjustment and Revitalization Plan by the state council in 2009. However the consumption and pollution generated by manufacturing industry and logistics industry linkage in China are also large at present. How to conduct manufacturing industry and logistics industry linkage by the low-carbon manner is one of most important issues under current low-carbon economy background. In this paper,the issue is studied and analyzed by constructing system dynamics model,which could propose suggestions for low-carbon linkage development of manufacturing industry and logistics industry.
基金Under the auspices of National Natural Science Foundation of China(No.41901158)China Postdoctoral Science Foundation(No.2019M651428)+1 种基金Humanities and Social Sciences Research Planning Fund from Ministry of Education of China(No.19YJC790138)The Soft Science Research Program of Shanghai Science and Technology development Commission(No.19692102400).
文摘As innovation and technological change have become increasingly important for the competitiveness and sustainable growth of firms,cooperative innovation is now crucial for traditional industries in the context of globalization.This paper proposes a framework for analyzing the spatial pattern of cooperative innovation for traditional industries in developing countries.Based on in-depth interviews with 35 firms in the oil equipment manufacturing industry in Dongying City,China,this study argues that different firms in the innovation pyramid have various innovation activity preferences and spatial patterns.Firms with high innovation abilities tend to cooperate with various partners that are geographically dispersed and continuously expanding,while firms with inferior abilities usually cooperate with nearby fixed partners.Due to the differences in innovation environment and actor locations,firms tend to make different choices regarding innovation types and models,which highlight the importance of personnel training and basic scientific research at the global scale and practical product research and development at the national scale.Additionally,talent flow is the most important way to realize relationships for firm innovation activity.
