The design methodology of injection molding die has been changed from two-dimensional drafting to three-dimensional solid modeling, which is due to many advantages over the conventional methodology in terms of design modification and data associativity. In addition to the solid modeling capability, it is required for a mold designer to utilize a database management system that facilitates efficient mold design. In the paper presented is the implementation of a software program which automatically generates three-dimensional mold-bases including standard parts and slider parts, conforming to given geometric constraints. It is based on a commercial CAD system (Unigraphics NX) along with related API (application program interface) libraries. The research is expected to reduce design efforts and simplify construction of a complex three-dimensional mold-base model that is comprised of standard parts and slider parts, by use of the three-dimensional database and automatized geometric dimensioning.

2D CAD is being replaced by 3D CAD to improve efficiency of product design and manufacturing. Therefore, converting legacy 2D drawings into 3D solid models is required. CSG based approaches construct solid models from orthographic views more efficiently than traditional B-rep based approaches. A major limitation of CSG based approaches has been the limited domain of objects that can be handled. This paper aims at extending the capabilities of CSG based approaches by proposing hint-based recognition of interacting solids of revolution which can handle interacting solids of revolution as well as isolated solids of revolution.

Context-aware engineering services in ubiquitous environments are emerging as a viable alternative to traditional engineering services. Most of the previous approaches are computer-centered rather than human-centered. In this paper, we present a Ubiquitous and Context-Aware computing Framework for collaborative virtual Engineering $(U-CAF\acute{E})$ services. The proposed approach utilizes BPEL-based (Business Process Execution Language) process templates for engineering service orchestration and choreography and adopts semantic web-based context-awareness for providing human-centered engineering services. The paper discusses how to utilize engineering contexts and share this knowledge in support of collaborative virtual engineering services and service interfaces. The paper also discusses how Web services and JINI (Java Intelligent Network Infrastructure) services are utilized to support engineering service federations and seamless Interactions among persons, devices, and various kinds of engineering services.

The integration of CAD and CAM is critical for computer aided process planning. Recently, STEP has been emerged and utilized as a product data exchange standard format in CAD/CAM areas. The assembly information consists of assembly component relations, assembly features, assembly directions and mating conditions. The purpose of this study is to develop an efficient algorithm to extract assembly information directly from the STEP based files and to generate automatically assembly process plan from the extracted assembly features. The developed algorithms will generate assembly information codes for STEP(AICS). The results from this study can be a reasonable link between design and manufacturing for developing better CAAPP(Computer-Aided Assembly Process Planning) systems.

This paper introduces a new approach for saving build time of hybrid rapid prototyping by decomposing a part into minimum number of layers. In the hybrid rapid prototyping, a part of a complicated shape is realized by adding layers of a simpler shape, each of which is obtained by machining a sheet of constant thickness from its top and bottom surfaces. Thus it is desired to decompose a given part into the minimum number of layers while guaranteeing each layer to be fabricated from the given sheets using a 3-axis milling machine. To satisfy these requirements, a concave edge-based algorithm is proposed to decompose a part into layers by considering the tool accessibility, the total number of layers, and the allowable sheet thickness.

Recent three-dimensional feature-based CAD systems based on solid or non-manifold modelling functionality have been widely used for product design in manufacturing companies. When product models associated with features are used in various downstream applications such as analysis, however, simplified and abstracted models at various levels of detail (LODs) are frequently more desirable and useful than the full detailed model. To provide multi-resolution models, the features need to be rearranged according to a criterion that measures the significance of the feature. However, if the features are rearranged, the resulting shape is possibly different from the original because union and subtraction Boolean operations are not commutative. To solve this problem, in this paper, the new concept of the effective zone of a feature is defined and identified using Boolean algebra. By introducing the effective zone, an arbitrary rearrangement of features becomes possible and arbitrary LOD criteria may be selected to suit various applications. Besides, because the effective zone of a feature is independent of the data structure of the model, the multi-resolution modelling algorithm based on the effective zone can be implemented on any 3D CAD system based on conventional solid representations as well as non-manifold topological (NMT) representations.

Recently, the requirements of multi-resolution models of a solid model, which represent an object at multiple levels of feature detail, are increasing for engineering tasks such as analysis, network-based collaborative design, and virtual prototyping and manufacturing. The research on this area has focused on several topics: topological frameworks for representing multi-resolution solid models, criteria for the level of detail (LOD), and generation of valid models after rearrangement of features. As a solution to the feature rearrangement problem, the new concept of the effective zone of a feature is introduced in the former part of the paper. In this paper, we propose a feature-based non-manifold modeling system to provide multi-resolution models of a feature-based solid or non-manifold model on the basis of the effective feature zones. To facilitate the implementation, we introduce the class of the multi-resolution feature whose attributes contain all necessary information to build a multi-resolution solid model and extract LOD models from it. In addition, two methods are introduced to accelerate the extraction of LOD models from the multi-resolution modeling database: the one is using an NMT model, known as a merged set, to represent multi-resolution models, and the other is storing differences between adjacent LOD models to accelerate the transition to the other LOD. We also suggest the volume of the feature, regardless of feature type, as a criterion for the LOD. This criterion can be used in a wide range of applications, since there is no distinction between additive and subtractive features unlike the previous method.

This paper discusses the methods of computing tool-paths for machining free-form surfaces on 3-axis CNC machines in die and mould making. In computational view this paper describes the characteristics and issues of the geometric information and the shape, which make computing tool-paths difficult. Important points that should be considered in devising a computing method are also discussed. A newly implemented method is explained and compared with an old method for a commercial CAM system. The implemented method is used in a commercial CAM system and the computing time for an example is presented.