Cloud manufacturing is one of the three key technologies that enable intelligent manufacturing.This paper presents a novel attribute-based encryption(ABE)approach for computer-aided design(CAD)assembly models to effec...Cloud manufacturing is one of the three key technologies that enable intelligent manufacturing.This paper presents a novel attribute-based encryption(ABE)approach for computer-aided design(CAD)assembly models to effectively support hierarchical access control,integrity verification,and deformation protection for co-design scenarios in cloud manufacturing.An assembly hierarchy access tree(AHAT)is designed as the hierarchical access structure.Attribute-related ciphertext elements,which are contained in an assembly ciphertext(ACT)file,are adapted for content keys decryption instead of CAD component files.We modify the original Merkle tree(MT)and reconstruct an assembly MT.The proposed ABE framework has the ability to combine the deformation protection method with a content privacy of CAD models.The proposed encryption scheme is demonstrated to be secure under the standard assumption.Experimental simulation on typical CAD assembly models demonstrates that the proposed approach is feasible in applications.展开更多
Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to...Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.展开更多
This paper presents a part count tool that predicts the part count for a particular product concept during the conceptual design phase. The part count tool will also aid in ranking the design concepts by the criterion...This paper presents a part count tool that predicts the part count for a particular product concept during the conceptual design phase. The part count tool will also aid in ranking the design concepts by the criterion of number of components for a product. This tool utilizes existing automated concept generation algorithms to generate the design concepts. It extracts the available data from the Design Engineering Lab Design Repository to determine an average number of parts per component type in the repository and then calculates an average part count for new concepts. The part count tool also uses an algorithm to determine how to connect two non-compatible components through the addition of mutually compatible components. While emphasis is placed on the average parts per product in evaluating designs, the overall functional requirement of the product is also considered.展开更多
Product cost is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product c...Product cost is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product cost is lost. In this paper, a method trying to reduce product cost at the design stage is proposed. This method is called Design to Cost (DTC). According to this method, product structure can be optimized with the application of value engineering and Design for Manufacturing/Assembly (DFMA) criteria in the conceptual stage of product design. During embodiment design, products are evaluated economically on the basis of the product model which includes manufacturing, assembly and test cost information. According to the results, products are redesigned before manufacture, and the production cost is reduced.展开更多
基金supported by the National Natural Science Foundation of China(62072348)the Science and Technology Major Project of Hubei Province(Next-Generation AI Technologies,2019AEA170).
文摘Cloud manufacturing is one of the three key technologies that enable intelligent manufacturing.This paper presents a novel attribute-based encryption(ABE)approach for computer-aided design(CAD)assembly models to effectively support hierarchical access control,integrity verification,and deformation protection for co-design scenarios in cloud manufacturing.An assembly hierarchy access tree(AHAT)is designed as the hierarchical access structure.Attribute-related ciphertext elements,which are contained in an assembly ciphertext(ACT)file,are adapted for content keys decryption instead of CAD component files.We modify the original Merkle tree(MT)and reconstruct an assembly MT.The proposed ABE framework has the ability to combine the deformation protection method with a content privacy of CAD models.The proposed encryption scheme is demonstrated to be secure under the standard assumption.Experimental simulation on typical CAD assembly models demonstrates that the proposed approach is feasible in applications.
文摘Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.
文摘This paper presents a part count tool that predicts the part count for a particular product concept during the conceptual design phase. The part count tool will also aid in ranking the design concepts by the criterion of number of components for a product. This tool utilizes existing automated concept generation algorithms to generate the design concepts. It extracts the available data from the Design Engineering Lab Design Repository to determine an average number of parts per component type in the repository and then calculates an average part count for new concepts. The part count tool also uses an algorithm to determine how to connect two non-compatible components through the addition of mutually compatible components. While emphasis is placed on the average parts per product in evaluating designs, the overall functional requirement of the product is also considered.
文摘Product cost is one of the most important factors affecting product market share. Traditionally, product costs are estimated after they are manufactured. However, in this way, the best opportunity to control product cost is lost. In this paper, a method trying to reduce product cost at the design stage is proposed. This method is called Design to Cost (DTC). According to this method, product structure can be optimized with the application of value engineering and Design for Manufacturing/Assembly (DFMA) criteria in the conceptual stage of product design. During embodiment design, products are evaluated economically on the basis of the product model which includes manufacturing, assembly and test cost information. According to the results, products are redesigned before manufacture, and the production cost is reduced.
