A new geometric constraint model is described, which is hierarchical and suitable for parametric feature based modeling. In this model, different levels of geometric information are represented to support various stages of a design process. An efficient approach to parametric featu-re based modeling is also presented, adopting the high level geometric constraint model. The low level geometric model such as B-reps can be derived automatically from the high level geometric constraint model, enabling designers to perform their task of detailed design.

A recent trend in computer graphics and image processing is to use Iterated Function System (IFS) to generate and describe both man-made graphics and natural images. Jacquin was the first to propose a fully automatic gray scale image compression algorithm which is referred to as a typical static fractal transform based algorithm in this paper. By using this algorithm, an image can be condensely described as a fractal transform operator which is the combination of a set of fractal mappings. When the fractal transform operator is iteratedly applied to any initial image, a unique attractor (reconstructed image) can be achieved. In this paper) a dynamic fractal transform is presented which is a modification of the static transform. Instead of being fixed, the dynamic transform operator varies in each decoder iteration, thus differs from static transform operators. The new transform has advantages in improving coding efficiency and shows better convergence for the decoder.

A method for representing quadric surfaces using NURBS is presented. By means of the necessary and sufficient conditions for NURBS cu-rves to precisely represent circular arcs and other conics, quadric surfaces can be represented by NURBS surfaces with fewer control vertices. The method can be used not only for NURBS surface representation of quadric surfaces, but also for rounding polyhedrons. Many examples are given in the paper.

This paper focuses on entirety ioterpretation, representation and reconstruction of three-dimensional volume data sets based on the physical model of the data. The data model is represented by thIee-dimensional geometric model.The surfaces inside the datafield are extracted and matched to the model stirfaces in order to reconstruct the new datafield based on the model. A conclusion is drawn that physical modeling provides a good basis and approach to interpret and represellt the data sets. This paPer also presents a subdivision algorithm to fast traJce B-spline curve and the colltrary algorithm is adopted to extract the geometry feature of the curve.

This paper presents a method to define a set of mutuaJly recursive inductive types, and develops a higherorder unilication algorithm for Anz extended with inductive types. The algorithm is an extension of Eiliott's algoritbJn for λ∑.The notation of normal forms plays a vital role in higher-order unification.The weak head normal forms in the extended troe theory is defined to reveal the ultimate "top level structures" of the fully normalized terms and types. Unification transformation rules are designed to deal with inductive types, a recursive operator and its reduction rule. The algoritlun can construct recuxsive functions automatically.

Synchronization is an important issue in multimedia systems which integrate a variety of temporally related media objects. One part of synchronization is the representation of temporal information. With the emerging illteractive multimedia, deterministic temporal models are replaced by nondeterministic ones with more expressiveness. This paper classifies temporal models by their expressiveness, and evaluates relevant nondeterministic temporal relations in multimedia data. Additionally, an intervalbased nondeterndnistic model based on a complete temporal operator set is proposed providing highlevel abstractions and a high degree of expressiveness for interactive multimedia systems.

In this paper, a series of design methods for relational databases based on generalization and aggregation sematics is set up. The relationship between a class and its subclass is considered as a scheme constraint. The concept of inheritance dependencies, which describes the multiple inheritance among schemes,is presented in the paper. It is shown that the inference rules for inheritance dependencies are sound and complete. Furthermore, a series of results about the closure of inheritance dependencies and the minimal set of inheritance dependencies, which are analogues to functional dependencies, is obtained. In order to describe the aggregation semalltics, the concept of aggregation dependencies is given. It is easy to implement these constraints under relational database management systems.

A fuzzy logic colltrol VLSI chip, F100, for industry process real-time colltrol has been designed and fabricated with 0.8pm CMOS technology. The chip has the features of simplicity flealbility and generality. This paper presents the fuzzy control inference method of the chip, its VLSI implementation, and testing design consideration.

For different delay models, the concept of sensitization can be very different.Thaditional concepts of sensitization cannot precisely describe circult behavior when the input vectors change very fast. Using Boolean process approach, this paper presents a new definition of sensitization for arbitrary input waveforms.By this new concept it is found that if the inputs of a combinational circult can change at any time, and each gate's delay varies witliln an interval (bounded gate delay model), then every path, which is not necessarily a single topological path, is sensitizable. fum the experimental results it can be seen that, all nonsensitizable paths for traditional concepts actually can propagate transitions along them for some input wavforms. However, specilied time between input transitions (STBIT) and nilnimum perndssible pulse width (E) are two major factors to make some paths non-sensitizable.

International use of the UNIX system in recent years provokes a need to expand its functionality. Extensions are needed to process data in various languages as the market requirement dictate[1,2]. With the advent of open systems and interfaces, the method of internationalization (I18N) has become standardized. Hanzix Association was founded by the fortitute of Software, The Chinese Academy of Sciences (ISAS, Beijing), Institute of Information Industry (III, Taipei) and Chinese University of Hong Kong (CUHK, Hong Kong), and its aim is to promote an open system standard for Chinese character (Hanzi) processing. This paper presents Hanzix, an open system environment to support Hanzi processing, including enhancemed recommended for Hanzi API,input method mechedsm, codeset conversion and armuncement, and reviews the current work.