一个作意图的输出和编辑系统

本文给出了一个对作弊图的输出算法，这个算法同其它的同类算法相比，具有更小的时间复杂性。并且由于此算法的参数是可控制的，所以对图的输出也是可控制的。另外，本文描述了一个图的显示和编辑系统ＧＬＥＡＭ，这个系统是基于所给出的新算法的，并且在本系统中使用了约束技术，使图输出更美观，合理。     

基于类比的学习式搜索算法AMO.GLSA

本文首先给出了学习式搜索的一个问题模型，然后（５）中ＧＬＳ搜索解题系统的基础上，本文描述了一个多目标学习搜索算法ＭＯ．ＧＬＳＡ，并对该算法作出一性能评价，最后，文中给出了一个基于类比的学习搜索算法ＡＭＯ．ＧＬＳＡ。     

知识库系统中的一种并发控制方法

本文给出了一个基于ＤＡＴＡＬＯＧ环境的知识库并发控制算法，算法的基础是两段锁（ＴＷＯＰＨＡＳＥＬＯＣＫＩＮＧ），它使用了相关和覆盖的概念，减少了被锁对象的数目，从而提高了系统的效率．最后给出了算法的正确性证明．     

CAGL—2——一个基于约束的图的显示系统

本文讨论了一些有关图的输出显示和如何解的约束的问题，及如何把约束这个概念用到图的输出中，ＣＡＧＬ－２是一个基于约束的图的自动输出系统，它可以方便地定义编辑和输出图的表示。     

面向对象数据模型到ERwin中ER图模型的转换

本文介绍一种面向对象的数据模型，这个模型ＣＯＲＥ模型为基础，给出ＬＯＧＩＣＷＯＲＫＳ公司的ＥＲｗｉｎ采用的ＥＲ图模型，接着着重讨论一种面向对象数据模型到ＥＲ图模型的转换算法。     

用可编程控制器实现BEPC安全联锁系统——PLC在测控系统中…

本文介绍一种设计安全联锁系统的新方法，它的基本思想是采用可编程控制器（ＰＲＯＧＲＡＭＭＡＢＬＥ ＣＯＮＴＲＯＬＥＲ或ＰＲＯＧＲＡＭＭＡＢＬＥＬＯＧＩＣＣＯＮＴＲＯＬＬＥＲ－ＰＬＣ）替代过去的继电器和逻辑的控制，组成分布系统，以提高要靠性和可维护性，增加灵活性，缩短工期，节省人力和资金，一台多媒体ＩＢＭ－ＰＣ兼容机有作业上位机，监控整个系统。     

复杂对象语义在ANGEL系统中的实现

ＡＮＧＥＬ系统是西北工业大学软件教研室在“八五”期间，为满足工程应用领域的特殊要求而研制开发的一个新一代工程数据库管理系统．文中首先介绍ＡＮＧＥＬ系统数据模型及其具体特征，并在此基础上，进一步讨论它对复杂对象丰富语义的表达和对复杂对象的建模和操作，重点阐述该系统数据操纵语言——ＡＤＭＬ（ＡＮＧＥＬｄａｔａｍａｎｉｐｕｌａｔｉｏｎｌａｎｇｕａｇｅ）的实现技术．鉴于该系统的具体特点，ＡＤＭＬ能对复杂对象语义，特别是复杂嵌套表模式中的引用及继承关系提供很好的支持     

一类排污问题在树图上的线性算法

ＭＥＧＩＤＤＯ等人证明了图搜索问题的ＮＰ完全性并给出一个树图上的算法，可在Ｏ（ｎ）时间内求解树的搜索数，在Ｏ（ｎｌｏｇ（ｎ））时间内求解树搜索方案．本文通过引入搜索方案边序表示法给出一个线性算法，可在Ｏ（ｎ）时间内同时求得树的搜索数和搜索方案．     

用可编程控制器实现BEPC安全联锁系统——PLC在测控系统中的应用

本文介绍一种设计安全联锁系统的新方法，它的基本思想是采用可编程控制器（ＰＲＯＧＲＡＭＭＡＢＬＥＣＯＮ－ＴＲＯＬＬＥＲ或ＰＲＯＧＲＡＭＭＡＢＬＥＬＯＧＩＣＣＯＮＴＲＯＬＬＥＲ—ＰＬＣ）替代过去的继电器和专用逻辑的控制，组成分布式系统，以提高可靠性和可维护性，增加灵活性，缩短工期，节省人力和资金。一台多媒体ＩＢＭ－ＰＣ兼容机用作上位机，监控整个系统。     

求多总线系统容错度的多项式时间算法

求多总线系统容错度的多项式时间算法陈四清，周六丁（重庆大学计算机科学系重庆６３００４４）ＰＯＬＹＮＯＭＩＡＬ－ＴＩＭＥＡＬＧＯＲＩＴＨＭＳＦＯＲＤＥＴＥＲＭＩＮＡＴＩＮＧＴＨＥＦＡＵＬＴ－ＴＯＬＥＲＡＮＣＥＤＥＧＲＥＥＯＦＭＵＬＴＩＢＵＳＳＹＳＴＥＭ...     

On-line Animated Visualization of Huge Graphs using a Modified Spring Algorithm

On-line graph drawing deals with huge graphs which are partially unknown. At any time, a tiny part of the graph is displayed on the screen. Examples include web graphs and graphs of links in distributed file systems. This paper discusses issues arising in the presentation of such graphs. The paper describes a system for dealing with web graphs using on-line graph drawing.     

The Grasper-CL graph management system

Grasper-CL is a system for manipulating and displaying graphs, and for building graph-based user interfaces for application programs. It is implemented in COMMON LISP and CLIM, and has been proven by use in a number of applications. Grasper-CL includes several advances in graph drawing. It contains a graph abstract datatype plus a comprehensive and novel language of operations on that datatype. The appearance of Grasper-CL graphs can be tailored by a wide variety of shape parameters that allow the application to customize the display of nodes and edges for different domains. Default values for shape parameters can be established at several levels. Grasper-CL employs a toolbox approach to graph layout: the system contains a suite of graph layout algorithms that can be applied individually, or in combination to produce hierarchical graph layouts. The system also contains an interactive graph browser.     

Straight-Line Drawing Algorithms for Hierarchical Graphs and Clustered Graphs

Hierarchical graphs and clustered graphs are useful non-classical graph models for structured relational information. Hierarchical graphs are graphs with layering structures; clustered graphs are graphs with recursive clustering structures. Both have applications in CASE tools, software visualization and VLSI design. Drawing algorithms for hierarchical graphs have been well investigated. However, the problem of planar straight-line representation has not been solved completely. In this paper we answer the question: does every planar hierarchical graph admit a planar straight-line hierarchical drawing? We present an algorithm that constructs such drawings in linear time. Also, we answer a basic question for clustered graphs, that is, does every planar clustered graph admit a planar straight-line drawing with clusters drawn as convex polygons? We provide a method for such drawings based on our algorithm for hierarchical graphs.     

Evaluating esthetics for user-sketched layouts of clustered graphs with known clustering information

This paper aims to empirically analyze the esthetics for user-sketched layouts of clustered graphs with known clustering information. In our experiments, given not only the adjacency list of a clustered graph but also its predefined clustering information, each participant was asked to manually sketch clustered graphs “nicely” from scratch on a tablet system using a stylus. Different from previous works, the main concern in this paper is on which graph drawing esthetics people favor when sketching their own drawings of clustered graphs with known clustering information. Another concern of this paper is on the esthetics of clustered graph layouts employed by participants which include not only characteristics and structures of the final graph layouts but also the behavior of user's sketching process (including layout creation and adjustment). By observing all layouts and drawing processes, the drawing strategies which participants applied and the drawing esthetics are analyzed. Results show that most participants were unsurprisingly able to draw graphs with clear presence of bridge edges and clustering cohesiveness; more importantly, to distinguish clusters within the restricted-size tablet screen during the drawing process, some of the participants were still able to make each cluster with fewer edge crossings, more symmetries, and more alignment of grid in a smaller drawing area where the cluster spreads. Our results support that to alleviate user's complex drawing tasks, aside from the grid-based editing function suggested by the previous work, graph drawing systems should also provide the clustering information if the structure of the graph to be drawn is known.     

关于互连网络的几个猜想

n-立方体是著名的互连网络,星图、煎饼图和冒泡排序图是由凯莱图模型设计出来的重要的互连网络。对换树（transposition tree）的凯莱图是一类特殊的凯莱图,星图和冒泡排序图分别是对换树为星和路的凯莱图。给出了关于n-立方体、星图、煎饼图、冒泡排序图和对换树的凯莱图的各一个猜想;提出了对换图的凯莱图的概念,进而由这一概念设计出了两个互连网络——圈图和轮图,并证明冒泡排序图和星图分别可嵌入圈图和轮图。     

Drawing complete binary trees inside rectilinear polygons

Most of graph drawing algorithms draw graphs on unbounded planes. However, there are applications that require graphs to be drawn on the plane inside a given polygon. In this paper, a new algorithm for planar orthogonal drawing of complete binary trees inside rectilinear polygons is presented. Uniform distribution of nodes of graphs on drawing regions is one of the aesthetics criteria in graph drawing. The goal of this paper is to produce planar orthogonal drawings with a relatively uniform node distribution and few edge bends. The proposed algorithm can be considered as a generalization of the H-tree layout method for rectilinear polygons. A new linear time algorithm is also given for bisecting rectilinear polygons into two equi-area rectilinear sub-polygons.     

一个新的无向图画图算法

将一般无向图的画图问题转化为函数优化问题,用遗传算法求目标函数的最优解的近似值,从而得到无向图自动画图算法的一个一般框架.新方法的特点是:不同的画图算法的框架都一样,所不同的只是反映无向图画图问题的美观标准的目标函数.其优点在于,算法统一、方法简单、容易实现、便于修改,并且易于并行化,可以直接用来画非连通图.     

一种用于Marching-Graph图形绘制的快速收敛布局算法

Marching-Graph是一种将图形隐喻技术和空间隐喻技术集成为一体的新的可视化方法.它为用户提供了高度可交互性地图,使用户可访问那些具有地理属性的信息的逻辑结构.它通过有效的人图交互和跨空间浏览为用户提供了一种可视分析和挖掘未知信息的机制,而不是将已知的信息呈现在地图上.然而,传统的力导向布局算法在达到力量均衡配置方面非常慢.为使一个图形布局收敛,它们通常需花费几十秒的时间.因此。当用户快速行进于地理区间时,那些力导向布局算法就不能满足快速绘制一系列图形的要求.提出了一种快速收敛布局方法,当用户在Marching-Graph中通过力导向布局逐步探究一系列图形时,它可以加速交互时间.通过结合辐射树绘图技术和力导向图形绘制方法来取得能量最小化的快速收敛.     

Characterizing proximity trees

Complete characterizations are given for those trees that can be drawn as either the relative neighborhood graph, relatively closest graph, Gabriel graph, or modified Gabriel graph of a set of points in the plane. The characterizations give rise to linear-time algorithms for determining whether a tree has such a drawing; if such a drawing exists one can be constructed in linear time in the real RAM model. The characterization of Gabriel graphs settles several conjectures of Matula and Sokal [17].This research was conducted while the author was at the School of Computer Science of McGill University. Research supported in part by NSERC and FCAR.This work was done when this author was visiting the School of Computer Science of McGill University.This work was done when this author was visiting the School of Computer Science of McGill University.     

基于遗传算法的平面图平面正交直线画图算法

提出了一种基于遗传算法的新的平面图平面正交直线画图算法,算法将平面图画图问题转化为约束优化问题,根据画图问题选定的美观准则构造约束函数,用遗传算法求解目标函数的最优解的近似值,从而得到平面图的平面正交直线画法。新算法的优点是方法简单,易于实现,画出的图形美观,算法稳定性好。实验结果表明,画图算法的最终结果不依赖于图的初始状态。