矢量法改进复合式相复励发电机调压特性

电抗变流复合式相复励有许多优点。本文根据相位和复励调节原理 ,用矢量法调整发电机主、副绕组相位 ,辅以相复励一、二次绕组匝数调整 ,改进三相同步发电机调压特性 ,在全系列相复励发电机开发中应用 ,取得较好效果。     

Creating and Rendering Convolution Surfaces

Implicit surfaces obtained by convolution of multi-dimensional primitives with some potential function, are a generalisation of popular implicit surface models: blobs, metaballs and soft objects. These models differ in their choice of potential function but agree upon the use of underlying modelling primitives, namely, points. In this paper a method is described for modelling and rendering implicit surfaces built upon an expanded set of skeletal primitives: points, line segments, polygons, arcs and planes. An analytical solution to the convolution is described. This solution offers a more accurate and robust representation of the resultant implicit surface than previous methods. An algorithm for ray-tracing the surfaces formed through convolution of any combination of these primitives is also outlined.     

Rapid and Accurate Contact Determination between Spline Models using ShellTrees

In this paper, we present an efficient algorithm for contact determination between spline models. We make use of a new hierarchy, called ShellTree , that comprises of spherical shells and oriented bounding boxes. Each spherical shell corresponds to a portion of the volume between two concentric spheres. Given large spline models, our algorithm decomposes each surface into Bézier patches as part of pre-processing. At runtime it dynamically computes a tight fitting axis-aligned bounding box across each Bézier patch and efficiently checks all such boxes for overlap. Using off-line and on-line techniques for tree construction, our algorithm computes ShellTrees for Bézier patches and performs fast overlap tests between them to detect collisions. The overall approach can trade off runtime performance for reduced memory requirements. We have implemented the algorithm and tested it on large models, each composed of hundred of patches. Its performance varies with the configurations of the objects. For many complex models composed of hundreds of patches, it can accurately compute the contacts in a few milliseconds.     

数控加工中凸干涉的处理

数控加工中的凸干涉一般发生于加工凸曲面高曲率骤变或几何拓扑信息突变的情况，即刀具运动的直线插补误差大于加工允差的条件下，凸干涉可采用插补误差值进行检查，对于尖角区域的干涉采用单点插入法进行修正处理，而尖凸区域的干涉则采用双点插入法进行修正处理     

基于示例学习的特征空间变换方法

特征空间是人工智能领域中经常用的基本概念之一，人工智能领域中的许多问题可以可以通过特征空间变换的方法化简和求解。文中提出了一种基于示例学习的特征空间变换方法。     

A Type of Triangular Ball Surface and its Properties

1IntroductionIntheCONSURFsystemll--3]developedbyA.A.Ball,thebasisfunctionsforcubicpolynomialsweredefinedbyandhencecubicBallcurveswithcontrolpointsPi(i=0,1,2,3)canberepresentedasp(u)=Z?=.B!(u)Pi,0Su51.TwotypesofhigherdegreegeneralizedBallbasisfunctionsandcorrespondingcurveshavebeenderivedbyWangl4]andSaidls]independently.InWang'spaper,generalizedBailbasisfunctionsofarbitrarydegreeweredefinedasfollows'.ifnisanevennumber.ifnisanoddnumberwherew~2u(1--u),05u51.Aparametriccurveofdegreentcall…     

混凝土构件火灾后损伤程度鉴定和加固

通过实际工程的调查和对砼材料在不同受火情况的试验研究，论证了采用外部特征综合分析并配合回弹试验等是判断砼构件火损程度的简便而实用的方法。     

二连盆地阿南凹陷辫状河三角洲砾岩储集层微相模式及含油性

通过对二连盆地阿南凹陷大量岩性剖面、测井曲线、岩石学特征、储集性能、沉积构造和沉积韵律分析,认为阿南凹陷下自垩统阿尔善组第三段砾岩,是一次大的事件性沉积和近物源、粗碎屑.低成分成熟度和低结构成熟度的多源复成分砾岩.首次提出阿三段砾岩属大型辫状河三角洲相,具有三角洲所具备的三角洲平原、三角洲前缘和前三角洲的三层结构,存在以牵引流为主的沉积构造和正韵律为主的剖面特征.最终细分出水下河道等十个微相,恢复了阿三段的岩相古地理环境,建立了相模式.指出,砾岩的储集空间为原生砾间孔、砾间洞、粒间缝、次生溶蚀孔和构造缝.砾岩的储集性能、含油性好坏和油藏展布受沉积微相、砾石支撑方式和构造缝发育程度的严格控制.     

一个软件质量评价系统的设计与实现

文中介绍了一个基于国家标准的软件质量度量模型和评价过程模型（简称ＪＴ－ＳＱＥ模型）的设计思想和主要技术，度量模型为四层次树形结构，评价过程及需求定义，度量和计分三步步骤，该模型为评价软件质量提出了一套可行的评价体系，并简单介绍了基于该模型的软件质量评价工具的结构和功能。