面向对象分析方法的目标探析

迄今为止，已有许多介绍和比较ＯＯＡ方法的工作，但缺少对ＯＯＡ方法的目标的深入探析。有鉴于此，本文系统分析了一些ＯＯＡ方法所声称的两个目标：（１）ＯＯＡ达到了需求分析的目标；（２）从ＯＯＡ向ＯＯＤ的过渡是自然的，从而指出许多ＯＯＡ方法未能完成需求分析的全部任务，从ＯＯＡ过渡到ＯＯＤ也不象一些方法所说的那样容易，同时讨论了从ＯＯＡ过渡到ＯＯＤ所存在的一些困难，也给出了实现从ＯＯＡ顺利过渡到ＯＯＤ的若干建议。     

OOP的计算模型研究

虽然ＯＯＰ（面向对象程序）已得到广泛应用，但由于ＯＯＰＬ）面向对象程序设计语言）、ＯＯＴ（面向对象技术）还缺乏坚实的理论基础，致使早期ＯＯＰＬ在对象、类、继承性和方法等面向对象的基本概念及其语义方面还缺乏一些致性表示和定义。本文作者在我媒体软件和大型信息系统开发实践中，详细分析了几种不同的ＯＯＰＬ语言，提出了ＯＯＰ的计算模型ＯＯＣＭ。ＯＯＣＭ从形式上定义了面向对象的基本概念、相关语义及其计算特征     

面向对象的管理信息系统开发研究

本文通过面向对象的管理信息系统开发研究,对ＯＯＳＥ在软件开发过程中的应用进行分析,论叙ＯＯＡ、ＯＯＤ和ＯＯＰ方法与技巧,阐明ＯＯＳＥ对缩短软件开发周期,提高系统性能具有重要作用。     

平面连通域VORONOI图的算法

本文探讨了平面多边形的ＶＯＲＯＮＯＩ图的性质，研究了通过合并多边形边界的两个子集生成平面单连通域ＶＯＲＯＮＯＩ图的分治算法，以及合并外轮廓和“岛”轮廓的ＶＯＲＯＮＯＩ图来生成平面多连通域ＶＯＲＯＮＯＩ图的算法。     

面向对象的软件需求分析

本文首先给出了面向对象的软件需求分析与面向过程分析方法的区别，并从软件需求的角度简要地讨论了ＯＯＲＡ所涉及的基本概念；依次评价了ＯＯＲＡ的四种起源。分析了ＯＯＲＡ的基本模型；比较了几种典型的ＯＯＲＡ途径。最后指出了从传统方法转向ＯＯＲＡ的几方面困难。     

OODBMS的管理机制和能力

该文以一个实际的ＯＯＤＢＭＳ产品──ＯＮＴＯＳＤＢ为例,详细讨论了ＯＯＤＢＭＳ所具备的诸多先进管理机制和能力,提供了现代ＯＯＤＢＭＳ研究和开发的诸多先进技术和特色。     

OODB的概念,发展与现状

本文在引入面向对象概念的基础上分析了面向对象数据库系统所具备的ＯＯ特色和先进的数据技术，在指出传统数学库管理系统的缺陷中重点讨论了ＯＯＤＢ的发展根源和所具有的能力，最后通过现有的ＯＯＤＢＭＳ产品的比较和名为ＯＮＴＯＳ的实际ＯＯＤＢＭＳ的详细讨论，全面展示了ＯＯＤＢ的发展现状和优势。     

求解初值问题的仿真算法和人工舍入误差的应用

求解初值问题的仿真算法和人工舍入误差的应用李旺尧（中科院计算数学与科学工程计算所）ＯＮＳＩＭＵＬＡＴＩＯＮＡＬＧＯＲＩＴＨＭＳＦＯＲＩＮＩＴＩＡＬＶＡＬＵＥＰＲＯＢＬＥＭＳＡＮＤＡＰＰＬＩＣＡＴＩＯＮＯＦＡＲＴＩＦＩＣＩＡＬＲＯＵＮＤ－ＯＦＦＥＲＲＯ...     

OO技术的现状与展望

本文描述ＯＯ技术的现状及展望，并针对Ｃ＋＋和ＶｉｓｕｌＦＯＸＰＲＯ某些缺陷进行一些ＯＯ技术的探讨。     

ONTOS DB──一个纯正的OODBMS

该文以典型的ＯＯＤＢＭＳ产品──ＯＮＴＯＳＤＢ为例,全面介绍了它作为现代ＯＯＤＢＭＳ所具备的ＯＯ机制、体系结构、管理能力、工具配置和先进特色。     

Vague集向Fuzzy集转化的一种新方法

提出Vague值向Fuzzy值转化的实用方法的定义。针对文献[6]中的一个Vague值向Fuzzy值转化的均值修正法,提出了加权均值修正法,并证明了这种方法同样是Vague值向Fuzzy转化的一种非常实用的方法。     

Virtual Triangulation Sensor Development, Behavior Simulation and CAR Integration Applied to Robotic Arc-Welding

Background: An increasing number of industrial robots are being programmed using CAR (Computer Aided Robotics). Sensor guidance offers a means of coping with frequent product changes in manufacturing systems. However, sensors increase the uncertainty and to preserve system robustness, a tool is needed that makes it possible to understand a sensor guided robot system before and during its actual operation in real life.Scope: A virtual sensor is developed and integrated in a CAR hosted environment. The real sensor is of a type commonly used in the arc-welding industry and uses a triangulation method for depth measurements. The sensor is validated both statically and dynamically by matching it with a real sensor through measurements in setups and by comparing a welding application performed in a real and a virtual work-cell created with a CAR application. The experimental results successfully validates its performance. In this context, a virtual sensor is a software model of a physical sensor with similar characteristics, using geometrical and/or process specific data from a computerized model of a real work-cell.     

The conversion of a dynamic B-spline curve into piecewise polynomials in power form

The evaluation of points and the computations of inflection points or cusps on a curve are often necessary in CAGD applications. When a curve is represented in a B-spline form, such computations can be made easier once it is transformed into a set of piecewise polynomial curves in power form. The usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in power form is done either by a knot refinement followed by basis conversions, or by applying a Taylor expansion on each knot span of a B-spline curve.Presented in this paper is a new algorithm to convert a B-spline curve into a set of piecewise polynomial curves in power form. Experiment shows that the proposed algorithm significantly outperforms the conventional approach when one or more control points of a B-spline curve are continuously moving.     

关于一种网格运行时结构的若干注记

进程是传统计算机系统的一个核心概念，自1960年出现以来一直沿用至今，进程的一个主要目的是为主体提供一种运行时结构，在操作系统和处理器硬件支持下，代表主体访问和使用各种资源，与传统的单机和并行机计算平台相比，网格计算机中进程所对应的概念面临新的挑战，包括网格资源繁杂、自主控制的条件下的单一系统映像和资源的共享与协同、与特定操作系统的松耦合、时间和空间的流动性、更高级的交互性，提出一种称为网程(grip)的运行时结构，试图解决上述问题，网程运行在网格操作系统之上，代表网格主体，访问和使用网格资源。     

On the equivalence between small-step and big-step abstract machines: a simple application of lightweight fusion

We show how Ohori and Sasano's recent lightweight fusion by fixed-point promotion provides a simple way to prove the equivalence of the two standard styles of specification of abstract machines: (1) in small-step form, as a state-transition function together with a ‘driver loop’, i.e., a function implementing the iteration of this transition function; and (2) in big-step form, as a tail-recursive function that directly maps a given configuration to a final state, if any. The equivalence hinges on our observation that for abstract machines, fusing a small-step specification yields a big-step specification. We illustrate this observation here with a recognizer for Dyck words, the CEK machine, and Krivine's machine with call/cc.The need for such a simple proof is motivated by our current work on small-step abstract machines as obtained by refocusing a function implementing a reduction semantics (a syntactic correspondence), and big-step abstract machines as obtained by CPS-transforming and then defunctionalizing a function implementing a big-step semantics (a functional correspondence).     

An Interactive Designing System with Virtual Sculpting and Virtual Woodcut Printing

In this paper, we propose an interactive designing method and a system based on it to create 3D objects and 2D images. This system consists of two subsystems for virtual sculpting to create a 3D shape and virtual printing to produce a picture with a printing block. In the virtual sculpting subsystem, a user can form solid objects with curved surfaces as if sculpting them. The user operates virtual chisels, and can remove or attach arbitrary shapes of ellipsoids or cubes from or to the workpiece. A 3D object generated by virtual sculpting looks like a real wooden sculpture. If using a board as a workpiece, a user can generate a virtual printing block. In the virtual printing subsystem, a user can synthesize a woodcut printing image from the virtual printing block mentioned above, a virtual paper sheet, and a printing brush. The user can synthesize a realistic woodcut print with a procedure similar to the actual woodcut printing.     

Error estimate for quasistatic history-dependent contact model

In this paper we consider a mathematical model which describes a quasistatic process for a viscoelastic body in contact with an obstacle or a foundation. The variational formulation of the problem is in the form of a system coupling a nonlinear integral equation with a history-dependent hemivariational inequality. We establish a fully discrete scheme of the abstract problem and derive a result on error estimate.     

Identification and data-driven model reduction of state-space representations of lossless and dissipative systems from noise-free data

We illustrate procedures to identify a state-space representation of a lossless or dissipative system from a given noise-free trajectory; important special cases are passive systems and bounded-real systems. Computing a rank-revealing factorization of a Gramian-like matrix constructed from the data, a state sequence can be obtained; the state-space equations are then computed by solving a system of linear equations. This idea is also applied to perform model reduction by obtaining a balanced realization directly from data and truncating it to obtain a reduced-order model.     

The importance of introducing a waiting time for Lattice Monte Carlo simulations of a polymer translocation process

For a standard Lattice Monte Carlo (LMC) simulation of a random walker subject to a bias, it is impossible to obtain both a correct mean velocity and diffusion coefficient. To correct this, a modified LMC algorithm has been developed where the introduction of a probability of remaining in the current state allows for a distribution of intervals between jumps. In this paper, we demonstrate the impact of this modification for a first-passage problem: the translocation of a polymer through a nanopore. We find that while either approach yields the correct mean first-passage time, the incorporation of a waiting time is necessary to obtain the correct spread of times.     

A disruption recovery plan in a three-stage production-inventory system

This paper proposes a recovery plan for managing disruptions in a three-stage production-inventory system under a mixed production environment. First, a mathematical model is developed to deal with a disruption at any stage while maximizing total profit during the recovery-time window. The model is solved after the occurrence of a disruption event, with changed data used to generate a revised plan. We also propose a new and efficient heuristic for solving the developed mathematical model. Second, multiple disruptions are considered, where a new disruption may or may not affect the recovery plans of earlier disruptions. The heuristic, developed for a single disruption, is extended to deal with a series of disruptions so that it can be implemented for disruption recovery on a real-time basis. We compare the heuristic solutions with those obtained by a standard search algorithm for a set of randomly generated disruption test problems, and that show the consistent performance of our developed heuristic with lower computational times. Finally, some numerical examples and a real-world case study are presented to demonstrate the benefits and usefulness of our proposed approach.