程序可视化技术在程序设计语言教学中的应用探讨

本文探讨了程序可视化技术在程序设计语言教学中的应用问题,并介绍了笔者所设计的用VB编写的冒泡排序算法的程序可视化应用实例。     

可视化程序界面设计题自动评分系统的设计与实现

以VB语言为例,研究了可视化程序设计类课程的上机考试界面题的自动评分问题,提出了关键问题的解决方法,并在实际中进行了验证。     

CASL语言可视化运行平台的设计与实现

随着可视化技术的不断发展,越来越多的程序设计语言和集成开发环境采用可视化技术,但是它们基本上只是采用了可视化编程,在软件开发阶段进行可视化,并未采用可视化动态运行程序。为此,进行了程序可视化运行的相关研究,设计出一个实现CASL语言可视化运行的平台。     

可视程序设计语言形式化规范及应用的研究

可视化技术的出现,减少了人和计算机交流的障碍。文章主要介绍可视化程序设计的基本概念、可视化程序设计语言的形式规范的描述及可视化技术在专家系统推理中的应用。     

VSQL图卡定义及编辑器实现

以图卡作为程序设计语言的基本语素，定义了一种可视化语言，用以解决空间数据库可视化查询问题，称为VSQL语言。文中主要介绍VSQL语言的语素－图卡的定义，并对图卡编辑器的C＋＋实现进行简介。     

基于可视化程序设计语言的编译系统

采用面向对象技术设计可视化程序设计语言的编译系统,通过对复杂的可视化图片语法进行分析,将各语法现象以语法单元类的形式进行抽象分类,提出了编译器－编译器的设计策略,给出了从可视化图片设计语言到伪指令代码的解决方法。主要研究在面向对象的编辑环境中如何实现满足硬件设备控制器的稳定、高效的编译系统。通过将可视化程序语言分析器(VPLPG)和小型的类C编译(LCC)器配合使用最终实现可视化程序设计语言的编译系统。     

基于边缘轮廓特征的实时车型分类

采用面向对象技术设计可视化程序设计语言的编译系统,通过对复杂的可视化图片语法进行分析,将各语法现象以语法单元类的形式进行抽象分类,提出了编译器-编译器的设计策略,给出了从可视化图片设计语言到伪指令代码的解决方法.主要研究在面向对象的编辑环境中如何实现满足硬件设备控制器的稳定、高效的编译系统.通过将可视化程序语言分析器(VPLPG)和小型的类C编译(LCC)器配合使用最终实现可视化程序设计语言的编译系统.     

混合编程与Fortran计算程序可视化

本文探索了用ＶＣ＋＋Ｆｏｒｔｒａｎ,ＯｐｅｎＧＬ进行混合编码的方法,该方法充分发挥了三种语言各自的优点,既能设计出画面丰富多彩,方便人机对话的界面,又有最大限度利用已有的有用Ｆｏｒｔｒａｎ语言编写的程序资源,并实现计算结果的可视化。用作者已有的用Ｆｏｒｔｒａｎ语言编写的源程序进行了尝试,结果良好。     

混沌动力学系统的图形化建模及可视化仿真研究

该文研究非线性混沌动力学系统的图形化建模及可视化仿真计算问题．通过建立统一的可视化仿真实验框架,实现了一个高度一体化的混沌系统图形建模和可视化仿真环境;与基于常规高级程序设计语言的混沌计算机模拟技术相比,该方法避免了传统意义上的混沌方程算法编程和调试过程,亦可对混沌参数进行自动摄动分析及最优设计。     

VSQL编辑器的行为模型定义

可视化语言是以图符为语素的语言，其语句是由可视化对象组成的，故指令的编写方式不同于传统字符语言的文本编辑方式，需要为其设计一种特殊的可视化语句编辑器，让用户来编写可视化语句。对VSQL的程序编辑器(Mach机)进行定义。介绍了：Mach的工作流程，并用一阶时态逻辑描述其行为，较好地说明了：Mach机互操作对象之间的关系，解决了Mach机复用问题，为VSQL实现可视化程序设计方法奠定了基础。     

可视化编程语言中small-screen与scaling-up问题解决方法探讨

由于目前可视化编程语言的设计工具主要集中于将其语素和数据应用二维图形对象来表示的范例来实现,针对其随之产生的small—screen与scaling—up问题,提出了一种在二维可视化编程环境下进行解决的方案。可以证明在解决实际问题中效果明显。     

动态图的实时三维可视化的稳定性算法

提出动态图的实时三维可视化及其稳定性的问题。讨论在图的实时重画中兼顾动态稳定性和美观性的平衡策略。在三维静态美观布局算法的基础上，给出了动态图的若干实时三维可视化的稳定性算法，并分析了这些算法的时间性能和适用范围。算法已应用在若干可视化编程环境。     

一种海上战场视景仿真系统的开发

为了逼真的演示海上多武器平台作战过程,设计并开发了一个基于Vega Prime的海上战场视景仿真系统,它是一个基于HLA的分布交互仿真系统的视景显示子系统.针对大量复杂三维实体建模中遇到的效率低下、难以有效管理的问题,首次提出引入基于增量模型的软件工程方法,以提高模型的可用性和可维护性,缩短开发周期.对于非视觉物理量可视化等Vega Prime中不具备的功能,通过在Vega Prime中嵌入OpenGL程序的方法加以实现,并解决了其中的关键技术.针对联邦时间推进造成的视景显示节点的画面不连续的问题,利用延迟一帧数据的方法予以解决.所开发的系统已在工程中得到应用,效果良好.     

飞行模拟训练分布交互视景仿真系统研究

创建了具有LOD(Levels of Detail)层次细节优化的三维地形模型、飞行器模型和环境物体模型,采用Vega软件的Symbology (仪表)模块、Creator建模中的DOF(Degrees Of Freedom)技术和Opengl程序设计技术,开发了精细的虚拟座舱仪表模型,并完成了基于飞行器视点和地面多视点的各视景仿真联邦成员的软件开发,构建了符合HLA标准的飞行模拟训练分布交互视景仿真系统,为飞行员和地面工作人员协同配合训练提供了先进的环境仿真实验平台.     

The PCG: An Empirical Study

Process communication graph (PCG) is the visual formalism used in a graph-based visual language (VL) for parallel programming. It combines control flow and data flow graphs into a single visual formalism, and supports different levels of abstraction at which parallel programs are expressed and moves to compositional programming. Empirical studies allow designers to put their designs to test in a direct and intentional interaction with users. For research projects this may be the only way to assess if their goals have been met. The case study presented here was conducted on programmers (students) solving parallel programming problems using the PCG formalism to construct parallel programs. The results of this evaluation indicate that users benefit from visual programming, even at the beginning of the learning curve.     

Realizing 3D Visual Programming Environments within a Virtual Environment

In the visual programming community, many interesting graphical metaphors have been reported upon for representing computer programs graphically. Most of them have a 2D or 2.5D appearance on the screen in order to reflect the inherent multi-dimensionality of the programming constructs being represented. By going into a three-dimensional representation, this reflection can go a stepfurther. With ever increasing3D graphics rendering capabilities on todays computers, it moreover becomes feasible to extend the dimensionality of the program (and data structure) depiction. We follow this approach by realizing 3D graphical programming techniques within CAEL, our interactive Computer Animation Environment Language. The paper elucidates how several concepts, traditionally found within the Virtual Environments area, can be utilized in the realization of three-dimensional Programming Environments.     

基于C共享库的MATLAB与Visual C#混合编程

MATLAB具有很强的数值计算能力,而Visual C#具有强大的图形用户界面的开发能力,两者的互补结合可以快速和高效地开发专业计算软件。为此,以实例的方式展示了由MATLAB生成C共享库,并在Visual C#中调用此C共享库来实现两者之间的混合编程。另外,对在Visual C#中调用C共享库时的一些需要注意的问题进行了讨论,并给出了外部程序调用由MATLAB生成的C共享库的一般步骤。实例证明通过C共享库来实现MATLAB与Visual C#混合编程的方法是行之有效的。     

Evidence in favor of visual representation for the dataflow paradigm: An experiment testing LabVIEW's comprehensibility

This paper reports an experiment that examined the comprehensibility of the LabVIEW programming representation. LabVIEW is a visual programming language (VPL) based on the dataflow paradigm. The experiment compared LabVIEW to a semantically equivalent textual language using three types of tasks: (1) tracing problems: given code and input values, subjects were asked what output the code would produce if executed. (2) Parallelism problems: given code with several program statements highlighted, subjects were asked about the sequence in which those statements could execute. (3) Debugging problems: given code and its specifications, subjects were asked to find a logic error in the code. The experiment measured the subjects’ time to solve the problems and accuracy of the answers. The subjects were upper-level university students who were intermediate-level programmers with no prior exposure to LabVIEW. Their performances showed differences due to representation for all three task types. Subjects using the textual representation completed the tracing problems significantly faster than subjects using the visual representation. In contrast, subjects using the visual representation were significantly faster for the parallelism problems and significantly more accurate for both the parallelism and debugging problems. These results contribute clear evidence for selected benefits of a visual representation for small-sized code segments, evidence that LabVIEW succeeds in highlighting data dependencies, and evidence that LabVIEW helps programmers to maintain an overview of their code. The authors consider the implications of these results for VPLs more generally.     

一道数字排列题算法演示的C#实现

编程解决实际问题,不仅通过大量的编程实践,掌握一定的编程技巧,同时也需要找到解决问题的正确方案。通过一道数字排列题的解决演示,灵活运用C#语言编程实现该问题算法的可视化演示。     

Packing circles within ellipses

The problem of packing circles within ellipses is considered in the present paper. A new ellipse‐based system of coordinates is introduced by means of which a closed formula to compute the distance of an arbitrary point to the boundary of an ellipse exists. Nonlinear programming models for some variants of 2D and 3D packing problems involving circular items and elliptical objects are given. The resulting models are medium‐sized highly challenging nonlinear programming problems for which a global solution is sought. For this purpose, multistart strategies are carefully and thoroughly explored. Numerical experiments are exhibited.