OpenGL技术在电磁散射理论中的应用

“图形电磁计算（ＧＲＥＣＯ）”技术被认为是目前电磁散射理论界分析高频区复杂目标雷达散射截面（ＲＣＳ）最有效的方法。该方法对计算机图形处理能力的高度要求，使其过去只有在昂贵的工作站平台上才能运行。提出一种在高性能微机上安装图形加速卡，利用ＷｉｎｄｏｗｓＮＴ下三维图形软件标准接口技术ＯｐｅｎＧＬ，从而提高微机的图形处理功能，在微机上实现ＧＲＥＣＯ技术的方法。该方法可在计算机屏幕上实时生成，显示复杂目标彩色图象及ＲＣＳ计算结果。     

彩色屏幕图形存取的汇编语言实现

本文在认真地分析了ＥＧＡ／ＶＧＡ图形控制器工作原理的基础上，编制了在图形方式下，屏幕保存和恢复的汇编语言程序，该程序经在ＴＵＲＢＯＣ，ＦＯＸＢＡＳＥ－ＰＬＵＳ和ＣＣＤＯＳ运行的各种语言环境下直接调用，效果良好。     

发动机CAD的工程数据库管理系统

论述了发动机ＣＡＤ的工程数据库管理系统（ＧＣＡＤ－ＥＤＢＭＳ）的功能以及在集成ＣＡＤ系统中的核心作用和实现方法，结合具体的工作站联网使用环境，使得ＧＣＡＤ－ＥＤＢＭＳ具有统一管理图形数据和非图形数据的能力，在网络环境下具有分布处理的能力。     

从第一代到第二代的计算机图形标准

计算机图形标准正在走向第二代。第一代标准为２Ｄ图形（ＧＫＳ）和３Ｄ图形（ＧＫＳ－３Ｄ，ＰＨＩＧＳ）提供了适用的接口，为计算机图象（ＣＧＭ）和设备接口（ＣＧＩ）规定了存储和交换格式。对计算机图形开发有影响的图形系统参考模型（ＣＧＲＭ）和通用名词术语逐渐成为一个究支。第二代计算机图形标准，以开放式图形环境为目标，易于扩展，配置和定制。适合于迅猛发展的计算机图形学界的需要，然而，这些标准并非是只限于单纯     

Lurie型控制系统的鲁棒决定稳定性

本文给出了Ｌｕｒｉｅ型间接控制系统ｘ＝Ｇ［Ｂ，Ｃ］ｘ＋Ｇ［Ｒ，Ｓ］ｆ（σ）；σ＝ｃ＾Ｔｘ－ρｆ（σ）；ｆ（σ）∈Ｋ［０，∞）；和直接控制系统ｘ＝Ｇ［Ｂ，Ｃ］ｘ＋Ｇ［Ｒ，Ｓ］ｆ（σ）；σ＝Ｃ＾Ｔｘ，ｆ（σ）∈Ｋ［０，∞），绝对稳定的若干充分条件。     

UNIX环境下非图形终端上数据全屏幕编辑通用软件的设计方法与实现

文章讲述了在ＩＢＭＲＩＳＣ／６０００ＡＩＸＶ３．２．５环境下利用ＣＵＲＳＥＳ库、Ｃ语言的指针机制和函数递归调用，开发非图形终端（ＨＴ－３８２）上通用数据全屏幕编辑软件的方法与实现。     

矩形板动力响应计算的迁移子结构法

矩形板动力响应计算的迁移子结构法杜国君，陈继荣（东北重型机械学院，齐齐哈尔）ＴＨＥＴＲＡＮＳＦＥＲＳＵＢＳＴＲＵＣＴＵＲＥＭＥＴＨＯＤＡＢＯＵＴＤＹＮＡＭＩＣＲＥＳＰＯＮＳＥＣＡＬＣＵＬＡＴＩＯＮＯＦＲＥＣＴＡＮＧＵＬＡＲＰＬＡＴＥＳ￥ＤｕＧｕｏ－ｊ...     

SDL支撑系统

ＳＤＬ是一种主要用于对电信系统性能制定确切的功能规格和描述的国际标准语言．本文描述了以ＣＣＩＴＴＳＤＬ’８８为标准，基于图形核心系统（ＧＫＳ）设计实现的ＳＤＬ支撑系统（３Ｓ），包括ＳＤＬ的图形方式（ＳＤＬ／ＧＲ）的文档录入和编辑工作、对录入的ＳＤＬ／ＧＲ文档进行正确性检查和将ＳＤＬ／ＧＲ文本翻译到文字短语方式表达的ＳＤＬ／ＰＲ文本等几部分．此工作的完成对于使用图形方式描述计算机系统，然后翻译到高级语言提供了可能．     

求解非线性矩阵特征值问题的一个三阶收敛的算法

求解非线性矩阵特征值问题的一个三阶收敛的算法陈广义，薛彦才（中国科学院沈阳计算所）ＡＣＵＢＩＣＡＬＬＹＣＯＮＶＥＲＧＥＮＴＡＬＧＯＲＩＴＨＭＦＯＲＳＯＬＶＩＮＧＮＯＮＬＩＮＥＡＲＥＩＧＥＮＶＡＬＵＥＰＲＯＢＬＥＭＳ￥ＣｈｅｎＧｕａｎｇ－ｙｉ；ＸｕｅＹ...     

一个面向作物育种过程的混合咨询系统

一个面向作物育种过程的混合咨询系统陈剑（清华大学系统工程研究所北京１０００８４）ＡＨＹＢＲＩＤＣＯＮＳＵＬＴＩＮＧＳＹＳＴＥＭＦＯＲＴＨＥＣＲＯＰＢＲＥＥＤＩＮＧＰＲＯＣＥＳＳ￥ＣＨＥＮＪｉａｎ（ＩｎｓｔｉｔｕｔｅｏｆＳｙｓｔｅｍｓＥｎｇｉｎｅｅｒｉ...     

防范边信道攻击的逆伪操作实现算法

针对模幂运算的二元表示(BR)算法在防范边信道攻击方面存在的问题,以消除运算单元之间的功耗差异为目的,提出模幂运算的逆伪操作算法。通过对基本BR算法和逆伪操作算法的实测功耗轨迹对比和对逆伪操作算法防范边信道攻击分析,证明逆伪操作运算已达到消除运算单元之间功耗差异的预期目标。     

3D对象动态方位邻接关系及双向关联表示

3D空间对象方位关系的表示和分析在空间数据库、地理信息系统、人工智能和机器人学等领域具有重要的意义。为了分析和处理复杂的3D空间对象的方位关系,讨论了3种3D空间对象方位关系的立体表示模型：3DR7模型、3DR27模型和3DR39模型,给出了方位关系的交集序列;研究了3D空间对象方位关系的动态邻接关系和处理方法;进一步给出了3D空间对象方位关系的双向映射模型。研究成果为3D空间对象方位关系在空间数据库和地理信息系统等领域的应用奠定了基础。     

Shapes In a Box: Disassembling 3D Objects for Efficient Packing and Fabrication

Modern 3D printing technologies and the upcoming mass‐customization paradigm call for efficient methods to produce and distribute arbitrarily shaped 3D objects. This paper introduces an original algorithm to split a 3D model in parts that can be efficiently packed within a box, with the objective of reassembling them after delivery. The first step consists in the creation of a hierarchy of possible parts that can be tightly packed within their minimum bounding boxes. In a second step, the hierarchy is exploited to extract the (single) segmentation whose parts can be most tightly packed. The fact that shape packing is an NP‐complete problem justifies the use of heuristics and approximated solutions whose efficacy and efficiency must be assessed. Extensive experimentation demonstrates that our algorithm produces satisfactory results for arbitrarily shaped objects while being comparable to ad hoc methods when specific shapes are considered.     

Estimation of three-dimensional objects from orthographic views with inconsistencies

Many algorithms to construct 3-D solid objects from orthographic views assume the bottom-up approach. This paper describes a method for identifying conflictions found in inconsistent views which improbably present complete objects and estimating solid objects. The sources of inconsistencies are extra segments, missing segments and incorrect classifications of line types (visible lines or hidden lines). In order to supply candidates for missing segments, probable segments are generated not from three views but from two views. The signs appearing in each step of the bottom-up algorithm are examined, and then the heuristic method for selecting more probable segments is developed. The estimation of solid objects and identification of incoherences are useful, for example, to detect improper input of three views and incorrect recognition of engineering drawings.     

Equal distance offset approach to representing and process planning for solid freeform fabrication of functionally graded materials

This paper deals with the representation and process planning for solid freeform fabrication (SFF) of 3D functionally graded material (FGM) objects. A novel approach of representation and process planning for SFF of FGM objects, termed as equal distance offset (EDO), is proposed. In EDO, a neutral arbitrary 3D CAD model is adaptively sliced into a series of 2D layers. Within each layer, 2D material gradients are designed and represented via dividing the 2D shape into several sub-regions enclosed by iso-composition contours. If needed, the material composition gradient within each of the sub-regions can be further specified by applying the equal distance offset algorithm to each sub-region. Using this approach, an arbitrary-shaped 3D FGM object with linear or non-linear composition gradients can be represented and fabricated via suitable SFF machines.     

Graph structure analysis based on complex network

In this paper, we propose a novel method to characterize graph structures based on complex network model. First, we show that a structural graph can be modeled as a small-world complex network, and, then, Complex Network Characteristics (including topological and dynamic characteristics) Representation of a Graph (CNCRG) is obtained. Based on these characteristics, graph classification/clustering for objects viewed from different directions and characteristic views identification for single objects are investigated on one synthetic image dataset and two real image datasets. Our experimental results showed that CNCRG achieves better object classification/clustering performance and also provides well-structured view spaces based on multi-dimensional scaling (MDS) and principal component analysis (PCA) embedding methods for graphs extracted from 2D views of 3D objects.     

3D Image Synthesis for B-Reps Objects

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 can be adjusted.Finally,an efficient algorithm is presented based on the AFD-matrix concept for converting the object in 3D space to 3D image in 3D discrete space.     

基于三视图的三维形体重建技术

基于工程图纸的三维形体的重建技术是根据形体的二维视图中的几何信息和拓扑信息,生成相应的三维形体,这是一个从爸维到高维的构造过程,文中提出了一个三维形体重建算法,该算法首先根据三视图生成形体的线框图,然后应用左邻边搜索策略求出线框图内的所有面及相应的极小环,最后利用Ｍｏｅｂｉｕｓ规则及工程图的性质,删除重建过程中生成的非法元素,该方法利用二几何基元和三维几何基元的几何性质及生成关系,减少了重建过程中     

虚拟环境中的快速碰撞检测算法

该文在Lin-Canny算法的基础上,提出一种虚拟环境下三维实体的动态、实时碰撞检测算法,并应用于柔性制造仿真系统中以检查工作环境中物体间的干涉状况,应用结果表明该算法在物体结构较复杂或运动的连贯性不好的情况下仍有较好的性能。