This paper presents a new algorithm for generating 3D images of B-reps objects with trimmed surface boundaries.The 3D image is a discrete voxel-map representation within a Cubic Frame Buffer(CFB). The definition of 3D images for curve,surface and solid object are introduced which imply the connectivity and fidelity requirements.Adaptive Forward Differencing matrix(AFD-matrix)for 1D-3D manifolds in 3D space is developed.By setting rules to update the AFD-matrix,the forward difference direction and stepwise c…

The lack of a systematic approach to the management of expertise represents a major difficulty for knowledge engineers.In this paper,we present a framework for assessing knowledge-based expert sys- tems.We show by examples.how this framework may be used to guide the development of these systems.Finally,we discuss the implications of this-work and suggest areas of interest for future research.

This paper shows an environment which supports the development of multi-thread dialogue interactive systems.The environment includes several tools and run-time support programs for the design and implementation of the user interface of an interactive system.First,methods of user interface specifica- tion with Elementary Nets are discussed.Then,the syntax of a user interface specification language based on Elementary Nets and the pre-compiler for the language as well as a graphic editor for Elemen- tary Nets…

A domain knowledge driven user interface development approach is described.As a conceptual de- sign of the user interface,the domain knowledge defines the user interface in terms of objects,actions and their relationships that the user would use to interact with the application system.It also serves as input to a user interface management system(UIMS)and is the kernel of the target user interface. The principal ideas and the implementation techniques of the approach is discussed.The user interface model,use…

As an application of artificial intelligence and expert system technology to database design,this paper presents an intelligent design tool NITDT,which comprises a requirements specification lan- guage NITSL,a knowledge representation language NITKL,and an inference engine with uncertainty reasoning capability.NITDT now covers the requirements analysis and conceptual design of database design.However,it is possible to be integrated with another database design tool, NITDBA,developed also at NIT to become an…

In order to improve the concurrency of multiversion database systems,a conservative MV locking-graph scheduler algorithm is proposed,which takes the power of MVS as a target.The algorithm combines the advantages of locking and graph,and does optimizing processes on read-only and write-only operations to reduce the blocks of transactions.The correctness and com- plexity of the algorithm are also provided.

Based on the theory of orthogonal program expansion,the paper proposes a method to trans- form programs by solving program equations.By the method,transformation goals are expressed in program equations,and achieved by solving these equations.Although such equations are usually too complicated to be solved directly,the orthogonal expansion of programs makes it possible to reduce such equations into systems of equations only containing simple constructors of programs.Then,the solutions of such equations can …

This paper proposes the idea of source-to-source conversion between two heterogeneous high-level programming languages.The conversion is based on formal definition and oriented to multi-pairs of lan- guages.The issues in conversion from PASCAL to C are also discussed.

Task partitioning is an important technique in parallel processing.In this paper,we investigate the optimal partitioning strategies and granularities of tasks with communications based on several models of parallel computer systems.Different from the usual approach,we study the optimal partitioning strate- gies and granularities from the viewpoint of minimizing T as well as minimizing NT~2,where N is the number of processors used and T is the program execution time using N processors.Our results show that t…

This paper discusses the portability of SAC-2/ALDES and reviews some applications in polynomial algebra.Furthermore,we indicate that the concept of the safety variable in the SAC-2/ALDES is not proper.When,for example,we used safety variable in isolating complex roots of polynomials, something wrong happened.

The database auto-design is an important problem in database research.In this paper we propose some new ideas and an approach called“logic approach”to implement the database auto-design.Given a relational scheme and a set of the functional dependencies for the relation we can obtain all of the functional dependencies and key for the relation and determine the normal form the relation satisfies.

In this paper,an improved graphic representation for Structured Program Design——N-S-Z (Nassi-Shneiderman-Zhou Diagram)is proposed.It not only preserves the advantages of the conventional graphic and non-graphic representations,but also adds some new features which will enhance the representa- tive power of the original diagram.