In the conceptual design stage of complex products, CBR(Case-Based Reasoning) tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and e...In the conceptual design stage of complex products, CBR(Case-Based Reasoning) tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and evaluation. The procedure is essentially a multiple criteria decision-making problem. The traditional multiple criteria programming is not flexible enough in executing the system evaluation algorithm due to both the limited experimental data and the lack of human experiences. To make the CBR tool to be more efficient, a new method for the best choice among the feasible schemes based on the Fuzzy AHP using Fuzzy numbers (FFAHP) is proposed. Since the final results become a problem of ranking the mean of fuzzy numbers by the optimism of decision-maker using the FFAHP, its execution is much more intuitive and effective than with the traditional method.展开更多
Based on the comparison of several methods of time series predicting, this paper points out that it is necessary to use dynamic neural network in modeling of complex production process. Because self feedback and mutua...Based on the comparison of several methods of time series predicting, this paper points out that it is necessary to use dynamic neural network in modeling of complex production process. Because self feedback and mutual feedback are adopted among nodes at the same layer in Elman network, it has stronger ability of dynamic approximation, and can describe any non linear dynamic system. After the structure and mathematical description being given, dynamic back propagation (BP) algorithm of training weights of Elman neural network is deduced. At last, the network is used to predict ash content of black amber in jigging production process. The results show that this neural network is powerful in predicting and suitable for modeling, predicting, and controling of complex production process.展开更多
Background Augmented assembly guidance aims to help users complete assembly operations more efficiently and quickly through augmented reality technology,breaking the limitations of traditional assembly guidance techno...Background Augmented assembly guidance aims to help users complete assembly operations more efficiently and quickly through augmented reality technology,breaking the limitations of traditional assembly guidance technology which is single in content and boring in way.Object registration is one of the key technologies in augmented assembly guidance process,which can affect the location and direction of virtual assembly guidance information in real assembly environment.Methods This paper presents an object registration method based on RGB-D camera,which combines Lucas-Kanade(LK)optical flow algorithm and Iterative Closet Point(ICP)algorithm.An augmented assembly guidance system for complex products through this method is built.Meanwhile,in order to compare the effectiveness of the proposed method,we also implemented object registration based on an open source augmented reality SDK Vuforia.Results An engine model and a complex weapon cabin equipment are taken as an case to verify this work.The result shows that the registration method proposed in this paper is more accurate and stable compared with that based on Vuforia and the augmented assembly guidance system through this method greatly improves the user's time compared with the traditional assembly.Conclusions Therefore,we can conclude that the object registration method mentioned in this paper can be well applied in the augmented assembly guidance system,which can do enhance the efficiency of assembly considerably.展开更多
This paper puts forward a complex inner product averaging method for calculating normal form of ODE. Compared with conventional averaging method, the theoretic analytical process has such simple forms as to realize co...This paper puts forward a complex inner product averaging method for calculating normal form of ODE. Compared with conventional averaging method, the theoretic analytical process has such simple forms as to realize computer program easily. Results can be applied in both autonomous and non-autonomous systems. At last, an example is resolved to verify the method.展开更多
Simulation technique is an efficient approach to realize the planning and scheduling of manufacturing process of products. An appropriate and efficient manufacturing process model is the basis and key of manufacturing...Simulation technique is an efficient approach to realize the planning and scheduling of manufacturing process of products. An appropriate and efficient manufacturing process model is the basis and key of manufacturing process simulation. By analyzing the features of large-sized and complex products, a method of manufacturing process modeling based on activity network is presented and a mapping algorithm of translating BOM/BOP into the manufacturing process model is designed in detail.展开更多
With the development of science and technology as well as the diversification and individualization of market demand,modern products update more and more rapidly.e rapid development of new products to satisfy the incr...With the development of science and technology as well as the diversification and individualization of market demand,modern products update more and more rapidly.e rapid development of new products to satisfy the increasingly improved and personalized customer demands greatly depends on the progress in the innovative design theory and performance optimization展开更多
Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl_2 complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd eluti...Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl_2 complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd elution of the carbonaceous products were measured and compared with those of commercial Pd/C catalyst. It indicates that the carbonaceous products are less active than Pd/C. However, the leaching of Pd from carbonaceous products is very small and much less than that from Pd/C.展开更多
复杂产品系统(CoPS)的研发过程具有高度的不确定性和复杂性,涉及诸多风险因素,众多学者针对相关风险进行研究、提供对CoPS研发风险管理的深刻洞见,以期提高CoPS研发成功率。因此,梳理89篇来自Web of Science、中国知网等数据库1998年至2...复杂产品系统(CoPS)的研发过程具有高度的不确定性和复杂性,涉及诸多风险因素,众多学者针对相关风险进行研究、提供对CoPS研发风险管理的深刻洞见,以期提高CoPS研发成功率。因此,梳理89篇来自Web of Science、中国知网等数据库1998年至2023年间国内外CoPS研发过程风险研究相关文献,从风险管理、风险生成和风险传播3个视角,对CoPS研发过程的风险研究工作进行归纳。结果显示在CoPS风险研究领域,风险管理的相关研究最广泛,文献数量从1998年开始逐渐增加,数量占比为78%,是领域内主要研究方向;风险生成相关研究受关注较少,文献数量占比为11%且在发表时间上较为分散,除2015年与2018年外每年不多于1篇;风险传播相关研究首篇文献发表于2013年,近年来受到持续关注,文献数量占比为11%。其中,风险管理相关研究主要从风险识别、风险评估、风险应对及风险控制4个核心环节进行展开,揭示在CoPS研发过程中如何通过多种方法有效识别并应对潜在风险;风险生成相关研究主要针对利益相关者的违约风险、技术风险等探究相关风险生成路径,并对风险因素间的相互作用进行初步探索;风险传播相关研究则分析揭示有关风险是如何在项目的不同阶段和部门间传播。同时可见,当前风险管理研究主要聚焦于单一风险因素的探讨,缺少系统地对CoPS研发过程中的流程或生命周期的风险识别、控制与应对的研究;风险生成研究缺乏对风险耦合产生风险事件机制的深入研究;风险传播研究在一定程度上忽视了风险因素间的动态影响,且相关案例数据的支撑不足。基于此,从研究内容、研究方法角度以及考虑当前及未来的外部宏观环境影响等方面,提出未来可进一步探讨的研究方向。展开更多
基金This project was partly supported bythe Key Programof the National Natural Science Foundation of China (79990580) .
文摘In the conceptual design stage of complex products, CBR(Case-Based Reasoning) tool is useful to offer a feasible set of schemes. Then the most adaptive scheme can be generated through a procedure of comparison and evaluation. The procedure is essentially a multiple criteria decision-making problem. The traditional multiple criteria programming is not flexible enough in executing the system evaluation algorithm due to both the limited experimental data and the lack of human experiences. To make the CBR tool to be more efficient, a new method for the best choice among the feasible schemes based on the Fuzzy AHP using Fuzzy numbers (FFAHP) is proposed. Since the final results become a problem of ranking the mean of fuzzy numbers by the optimism of decision-maker using the FFAHP, its execution is much more intuitive and effective than with the traditional method.
文摘Based on the comparison of several methods of time series predicting, this paper points out that it is necessary to use dynamic neural network in modeling of complex production process. Because self feedback and mutual feedback are adopted among nodes at the same layer in Elman network, it has stronger ability of dynamic approximation, and can describe any non linear dynamic system. After the structure and mathematical description being given, dynamic back propagation (BP) algorithm of training weights of Elman neural network is deduced. At last, the network is used to predict ash content of black amber in jigging production process. The results show that this neural network is powerful in predicting and suitable for modeling, predicting, and controling of complex production process.
基金the National Defense Basic Scientific Research,China(JCKY2016605B006)National Defense Basic Scientific Research,China(JCKY2017203B071).
文摘Background Augmented assembly guidance aims to help users complete assembly operations more efficiently and quickly through augmented reality technology,breaking the limitations of traditional assembly guidance technology which is single in content and boring in way.Object registration is one of the key technologies in augmented assembly guidance process,which can affect the location and direction of virtual assembly guidance information in real assembly environment.Methods This paper presents an object registration method based on RGB-D camera,which combines Lucas-Kanade(LK)optical flow algorithm and Iterative Closet Point(ICP)algorithm.An augmented assembly guidance system for complex products through this method is built.Meanwhile,in order to compare the effectiveness of the proposed method,we also implemented object registration based on an open source augmented reality SDK Vuforia.Results An engine model and a complex weapon cabin equipment are taken as an case to verify this work.The result shows that the registration method proposed in this paper is more accurate and stable compared with that based on Vuforia and the augmented assembly guidance system through this method greatly improves the user's time compared with the traditional assembly.Conclusions Therefore,we can conclude that the object registration method mentioned in this paper can be well applied in the augmented assembly guidance system,which can do enhance the efficiency of assembly considerably.
文摘This paper puts forward a complex inner product averaging method for calculating normal form of ODE. Compared with conventional averaging method, the theoretic analytical process has such simple forms as to realize computer program easily. Results can be applied in both autonomous and non-autonomous systems. At last, an example is resolved to verify the method.
文摘Simulation technique is an efficient approach to realize the planning and scheduling of manufacturing process of products. An appropriate and efficient manufacturing process model is the basis and key of manufacturing process simulation. By analyzing the features of large-sized and complex products, a method of manufacturing process modeling based on activity network is presented and a mapping algorithm of translating BOM/BOP into the manufacturing process model is designed in detail.
文摘With the development of science and technology as well as the diversification and individualization of market demand,modern products update more and more rapidly.e rapid development of new products to satisfy the increasingly improved and personalized customer demands greatly depends on the progress in the innovative design theory and performance optimization
文摘Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl_2 complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd elution of the carbonaceous products were measured and compared with those of commercial Pd/C catalyst. It indicates that the carbonaceous products are less active than Pd/C. However, the leaching of Pd from carbonaceous products is very small and much less than that from Pd/C.
文摘复杂产品系统(CoPS)的研发过程具有高度的不确定性和复杂性,涉及诸多风险因素,众多学者针对相关风险进行研究、提供对CoPS研发风险管理的深刻洞见,以期提高CoPS研发成功率。因此,梳理89篇来自Web of Science、中国知网等数据库1998年至2023年间国内外CoPS研发过程风险研究相关文献,从风险管理、风险生成和风险传播3个视角,对CoPS研发过程的风险研究工作进行归纳。结果显示在CoPS风险研究领域,风险管理的相关研究最广泛,文献数量从1998年开始逐渐增加,数量占比为78%,是领域内主要研究方向;风险生成相关研究受关注较少,文献数量占比为11%且在发表时间上较为分散,除2015年与2018年外每年不多于1篇;风险传播相关研究首篇文献发表于2013年,近年来受到持续关注,文献数量占比为11%。其中,风险管理相关研究主要从风险识别、风险评估、风险应对及风险控制4个核心环节进行展开,揭示在CoPS研发过程中如何通过多种方法有效识别并应对潜在风险;风险生成相关研究主要针对利益相关者的违约风险、技术风险等探究相关风险生成路径,并对风险因素间的相互作用进行初步探索;风险传播相关研究则分析揭示有关风险是如何在项目的不同阶段和部门间传播。同时可见,当前风险管理研究主要聚焦于单一风险因素的探讨,缺少系统地对CoPS研发过程中的流程或生命周期的风险识别、控制与应对的研究;风险生成研究缺乏对风险耦合产生风险事件机制的深入研究;风险传播研究在一定程度上忽视了风险因素间的动态影响,且相关案例数据的支撑不足。基于此,从研究内容、研究方法角度以及考虑当前及未来的外部宏观环境影响等方面,提出未来可进一步探讨的研究方向。