Basic research in computer science and software engineering at SKLCS

The State Key Laboratory of Computer Science (SKLCS) is committed to basic research in computer science and software engineering. The research topics of the laboratory include: concurrency theory, theory and algorithms for real-time systems, formal specifications based on context-free grammars, semantics of programming languages, model checking, automated reasoning, logic programming, software testing, software process improvement, middleware technology, parallel algorithms and parallel software, computer graphics and human-computer interaction. This paper describes these topics in some detail and summarizes some results obtained in recent years.     

Scout: a data-parallel programming language for graphics processors

Commodity graphics hardware has seen incredible growth in terms of performance, programmability, and arithmetic precision. Even though these trends have been primarily driven by the entertainment industry, the price-to-performance ratio of graphics processors (GPUs) has attracted the attention of many within the high-performance computing community. While the performance of the GPU is well suited for computational science, the programming interface, and several hardware limitations, have prevented their wide adoption. In this paper we present Scout, a data-parallel programming language for graphics processors that hides the nuances of both the underlying hardware and supporting graphics software layers. In addition to general-purpose programming constructs, the language provides extensions for scientific visualization operations that support the exploration of existing or computed data sets.     

Adding graphics to a high-level programming language

When graphics input/output capabilities are added to a programming language originally designed with a text stream input/output model, various design decisions affect the ease with which the graphics facilities are learned and used by applications programmers. In adding window system facilities to the Icon programming language, some design decisions were made very differently from the conventional wisdom, resulting in substantial benefits for programmers. In addition, some pre-existing Icon language features have proved to be useful in graphics programming.     

The role of expert systems in producing log interpretation software

Abstract: Log interpretation science is a controversial and rapidly changing domain. Designing interpretation models is a highly experimental process which involves trials with a computer program as an integral part of the design. Therefore conventional software engineering techniques, which require a complete specification of the problem before the program is written, are often not applicable or fail to produce high quality software. The development of expert systems has provided the techniques, tools, and capabilities to let us seek alternate methods to produce log interpretation software: exploratory programming environments and automatic programming systems. An exploratory programming environment combines the power of interactive graphics and programming tools to merge the design and programming tasks into a single process where model and program develop together. An automatic programming system will embody the knowledge of the programming process and of some log interpretation heuristics to produce log processing programs from interactive specifications expressed in familiar terms. These facilities will allow log interpretation model designers, who are non-computer specialists, to produce high quality software as the end result of a model design.     

DGLa: A Distributed Graphics Language

A distributed graphics programming language called DGLa is presented,which facilitates the development of distributed graphics application.Facilities for distributed programming and graphics support are included in it,It not only supports synchronous and asynchronous communication but also provides programmer with multiple control mechanism for process communication.The graphics support of DGLa is powerful,for both sequential graphics library and parallel graphics library are provided.The design consideration and implementation experience are discussed in detail in this paper.Application examples are also given.     

Computer graphics Part 2—Software techniques

In the previous paper¹ we considered the factors affecting the choice of configuration for a proposed graphics installation. This paper looks more closely at the problems of software, an aspect which can have a far greater impact on the final success of the system.

The first part of this paper reviews the graphics software packages which will be required. Some of these are supplied by the manufacturer; others will have to be developed by the installation's own programming staff. This is followed by a discussion of programming techniques which have proved to be effective in a practical design environment.     

Using CAD/CAM for three-dimensional linear programming models

A software package has been developed for the Intergraph CAD/CAM system to illustrate three-dimensional linear programming models. The software, called LPVAX, allows a user to enter a linear programming model with three variables and receive a complete solution including sensitivity analysis. The use may then, by menu commands, enter the solution into a graphics file for the CAD/CAM system to convert into graphics displays. The user can display all of the constraints and the objective function in a three-dimensional graph. The solution solid can be viewed and rotated continuously, a key technique for user understanding of the feasible solution space. Constraints can be removed from or added to the display singly or in groups so that any number of the constraints may be displayed immediately. The system is menu-driven for ease of use.     

The Specification of Computer Graphics Systems

Specification techniques for computer graphics systems should emulate those employed in the specification of computer communication protocols and software systems, not the specification of programming languages.     

Construction of Interactive Programs in Computer Graphics

In interactive computer graphics, one often finds a gap between sophisticated algorithms, using very high level data structures, and poor methods of program and object construction. Particular programming languages are too readily adopted for solving problems, before a precise specification of the problem to be solved has been formulated.
This paper shows that progress can be made by using modern engineering methods to specify and develop graphical software. Two programming techniques are studied here: the algebraic specification of data types and a functional static modular method of problem statement.
The paper also discusses these proposals in the context of other modes of computer graphics specification and programming.     

Teaching a modern graphics pipeline using a shader-based software renderer

This paper presents the syllabus for an introductory computer graphics course that emphasizes the use of programmable shaders while teaching raster-level algorithms at the same time. We describe a Java-based framework that is used for programming assignments in this course. This framework implements a shader-enabled software renderer and an interactive 3D editor. Teaching shader programming in concert with the low-level graphics pipeline makes it easier for our students to learn modern OpenGL with shaders in our follow-up intermediate course. We also show how to create attractive course material by using COLLADA, an open standard for 3D content exchange, and our approach to organizing the practical course.     

基于LabVIEW和Matlab混合编程的竹片检测系统设计

针对竹片生产过程完全依靠人工干预,无法满足快速、高效生产要求的现状,借助具有图形化编程语言的LabVIEW以及强大的矩阵运算和图形处理功能的Matlab软件平台,研究和设计基于LabVIEW和Matlab混合编程的竹片检测系统,实现竹片表面缺陷实时准确的检测。经测试,竹片正确识别率达92%,检测速率8片/s以上,满足精度要求和生产需要。     

Hardware/software trade-offs for bitmap graphics on the blit

The Blit is an experimental bitmap graphics terminal built for research into interactive computer graphics on the UNIX time-sharing system. The hardware is inexpensive and the graphics functions are implemented entirely in software. Nevertheless, the graphics performance of the Blit is comparable or superior to some displays with special-purpose graphics hardware. This paper explains the paradox by referring to some principles of design: the hardware and software should be designed together to complement each other; carefully designed software can outperform infelicitous hardware; and simplicity of design leads to efficiency of execution. These principles are illustrated by examples from the Blit hardware and software and comparisons with other systems.     

An approach to the formal specification of computer graphics systems

This paper discusses the approach to formal specification of computer graphics systems developed by the ANSI X3H3 committee (Computer Graphics Programming Languages) in the United States. ANSI's specification philosophy aims to gradually replace existing informal English language specifications with more formal ones without sacrificing the readibility and usefulness of standards documents. The specification techniques used are derived from those presently employed in the specification of computer communication protocols and the specification of software systems, not those used for the specification of programming languages. The specifications consist of three parts: the interface between both graphics and the host language and graphics and the graphical display device, the structure of the graphics system, and the functions that are performed by the graphics system. The specifications are based on abstract data types. These data types, together with the operations which can be performed on them, are used to describe the structure and functions of the graphics system. Using these techniques, X3H3 has developed a complete formal specification for a minimal graphics system. Extracts from this specification are included here.     

电子显示屏的单片机控制系统

文中介绍了电子显示屏单片机控制系统的方法，论述了其工作原理，给出电路原理框图及软件编程方法。     

EasyFEM—An object-oriented graphics interface finite element/finite volume software

An object-oriented finite element/finite volume software, EasyFEM, has been developed. The software, with a fully interactive graphics interface, analyses heat transfer, solid mechanics, and fluids problems by the finite element and the finite volume methods. The Coad and Yourdon methodology is used to describe the general structure of classes and objects implemented by the software. Details of the object-oriented classes for both the graphics pre- and post-processors, as well as for the analysis solutions, are described. Several case studies with graphical representations of numerical solutions are presented to illustrate some functionalities of the software.     

Current trends in computer graphics

A look at the trends in computer graphics is given by analyzing important areas that affect the progress of graphics like hardware, input and output devices for graphics, programming languages, systems developments and advances in techniques and algorithms for computer graphics. Then attention is given to new and expanded application areas for the future, as well as some problems that will persistently confront people working in graphics.     

基于GDI+技术的坐标图形解决方案的研究

图形软件的开发是许多工业领域的软件的重要组成部分。在阐述GDI＋技术的一般原理的基础上,根据工程中对坐标图形的实际需求,针对目前窗体程序图形开发的复杂性和低效性,提出了更抽象的坐标图形解决方案。并详细介绍了从坐标建模开始,逐步实现坐标的建立、图形数据的转换、光标线的应用和图形多样显示的过程,为使用坐标图形的相关领域提供了一种行之有效的方案。     

图形软件包XGL的设计方法与结构

本文概要地介绍了面向对象程序设计的思想和方法。给出了Ｓｕｎ平台上的图形软件包ＸＧＬ的面向对象设计方法、结构及其实现。     

The application visualization system: a computational environmentfor scientific visualization

A software system for developing interactive scientific visualization applications quickly, with a minimum of programming effort, is described. This application visualization system (AVS) is an application framework targeted at scientists and engineers. The goal of the system is to make applications that combine interactive graphics and high computational requirements easier to develop for both programmers and nonprogrammers. AVS is designed around the concept of software building blocks, or modules, which can be interconnected to form visualization applications. AVS allows flow networks of existing modules to be constructed using a direct-manipulation user interface, and it automatically generates a simple user interface to each module