RAPID prototyping, MANUFACTURING processes, MANUFACTURES, NEW product development, CONCURRENT engineering, JOB analysis, PROTOTYPES, TIME to market (New products), and ECONOMIC trends

This paper discusses the current status of layer-based manufacturing Rapid Prototyping (RP) technology and how it is being successfully implemented as a tool for product development (PD). A brief introduction to RP is given, focusing on the limitations of existing technology. Future trends for RP development are then discussed with further consideration for software issues in future applications. [ABSTRACT FROM AUTHOR]

WORK design, PROTOTYPES, and MANUFACTURES

Although prototyping is a technique widely used in manufacturing industry during the design development and manufacture of a new or updated project, the technique is rarely used to test out options during the design of a manufacturing system. The work organization action simulation was developed in response to a need identified in the training of engineers. Such an approach can be used to prototype sociotechnical systems and explore technical options in association with the organizational structure. [ABSTRACT FROM AUTHOR]

ALGORITHMS, MANUFACTURES, ENGINEERING, MANUFACTURING processes, NEW product development, BIOMEDICAL engineering, COMPUTER simulation, and VIRTUAL reality

This paper proposes a multi-material virtual prototyping (MMVP) system that integrates the virtual reality (VR) and the layered manufacturing (LM) technologies for digital fabrication of heterogeneous multi-material prototypes for advanced product development and biomedical engineering. The system consists mainly of two algorithms for sequential and concurrent multi-toolpath planning, and a virtual prototyping system. The algorithms adopt a topological hierarchy-sorting algorithm to establish the hierarchy relationship of multi-material slice contours for facilitating toolpath planning of multi-material layered manufacturing (MMLM). Subsequently, the sequential multi-toolpath planning algorithm generates sequential toolpaths that avoid redundant tool movements. To reduce build time further, the concurrent multi-toolpath planning algorithm generates collision-free concurrent toolpaths. Based on the hierarchy information, a bounding box can be adopted to approximate envelopes of contour families of the same material property to simplify detection of tool collisions. The algorithms are integrated to form the MMVP system for planning, stereoscopic simulation, and validation of multi-toolpaths for MMLM. [ABSTRACT FROM AUTHOR]

MANUFACTURING processes, RAPID prototyping, PRODUCTION methods, INDUSTRIAL engineering, ARTIFICIAL intelligence, ARTIFICIAL neural networks, and MANUFACTURES

In an earlier work (Ransing et al . 1995), we represented the causal relationship in a defect-metacause-rootcause form. This representation was perceived to be of considerable importance to the research community as well as industry, as it is applicable to any form of manufacturing process. Based on this representation we proposed 'A Semantically Constrained Bayesian Network' for the diagnostic problems (Lewis and Ransing 1997). In this paper, we develop another popular Artificial Intelligence tool, 'Feedforward Neural Network', for such diagnostic problems. The network is constrained to defect-metacause-rootcause topology and it has been shown that metacause concepts can be successfully associated with the hidden nodes. The errors are calculated at both the output layer and the hidden layer. Although the learning process is based on the back-propagation algorithm with a momentum term, the weight changes would occur at a link connecting a node only if at least one of the nodes connected to it in the preceding layer has non-zero activation. The theoretical analysis of such constrained learning is given and it is shown that the network behaviour is acceptable for the diagnostic problems considered. [ABSTRACT FROM AUTHOR]

PRODUCT design and MANUFACTURES

The design of a new product usually takes shape gradually over time. Traditionally prototypes follow the design and are concluded before product launch. To decrease the time-to-launch, one may want to start prototype tests in advance of the design completion. However, with a slowly evolving design, modifications (in design) between subsequent prototypes can be significant, thereby increasing the time required for prototyping. This effect would be enhanced further if the prototyping time per unit of design change (sensitivity) is high. Using analytical models, we show how the interaction between the speed of evolution and the sensitivity impacts overlapping strategies. In scenarios where the impact of design changes can only be measured in discrete units, we formulate a shortest-path model and show how discreteness may limit the number of used prototypes. [ABSTRACT FROM AUTHOR]

RAPID prototyping, MANUFACTURES, SURGERY, and PROSTHETICS

Reports on the surgical applications of rapid prototyping techniques developed for the manufacturing industry in Great Britain. Use of stereolithography in creating models for surgery; Application in making prosthetics. INSETS: A NEW NOSE;SLICE BY SLICE.

MANUFACTURING processes, RAPID prototyping, MANUFACTURES, and INDUSTRIAL research

Variation reduction of manufacturing processes is an essential objective of process quality improvement. It is highly desirable to develop a methodology of variation source identification that helps quickly identify the variation sources, hence leading to quality improvement and cost reduction in manufacturing systems. This paper presents a variation source identification method based on the analysis of the covariance matrix of process quality measurements. The identification procedure utilizes the fact that the eigenspace of the quality measurement covariance matrix can be decomposed into a subspace due to variation sources and a subspace purely due to system noise. The former subspaces for different samples will be the same if the same variation sources dominate. A testing procedure is presented, which can determine the closeness of the subspaces under sampling uncertainty. A case study is conducted to illustrate the effectiveness of this methodology. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006. [ABSTRACT FROM AUTHOR]