模具CAD／CAM柔性系统中零件与结构三维信息建模方法研究

本文讨论了用三维实体结构型技术（ＣＳＧ）发开模具ＣＡＤ／ＣＡＭ系统，并且运用面向对象的分析方法分别建立了零件三维信息及其相互关系的数据结构，由此可以作为开展模具ＣＡＤ／ＣＡＭ系统软件的基础。     

Using NNF to transform conceptual data models to object-oriented database designs

More work is needed on devising practical, but theoretically well-founded procedures for doing object-oriented database (OODB) design [17]. Design procedures should also be flexible enough to take into account various application characteristics (such as whether objects are very large or are read-only). In this paper, we present and discuss an OODB design procedure that addresses these problems. The procedure is practical in the sense that it is based on a common family of conceptual models and in the sense that it does not expect users to supply esoteric, difficult-to-discover, and hard-to-understand constraints (such as multivalued dependencies), nor does it make hard-to-check and easy-to-overlook assumptions (such as the universal relation scheme assumption). At the same time, the procedure is well-founded and formal, being based on NNF (Nested Normal Form [21]), a new theoretical result that characterizes properties of interest in designing complex objects. It is also adaptable to various applications characteristics.     

面向对象开发方法的基本要求及评价标准

本文从实际应用角度分析了面向对象开发方法应 该具备的主要技术特征，对面向对象开发方法的重要概念和存在的问题进行了详细讨论了并提出了一些具体的评价标准。。     

MCNP Output Data Analysis with ROOT (MODAR)

MCNP Output Data Analysis with ROOT (MODAR) is a tool based on CERN's ROOT software. MODAR has been designed to handle time-energy data issued by MCNP simulations of neutron inspection devices using the associated particle technique. MODAR exploits ROOT's Graphical User Interface and functionalities to visualize and process MCNP simulation results in a fast and user-friendly way. MODAR allows to take into account the detection system time resolution (which is not possible with MCNP) as well as detectors energy response function and counting statistics in a straightforward way.

Program summary

Program title: MODARCatalogue identifier: AEGA_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGA_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 155 373No. of bytes in distributed program, including test data, etc.: 14 815 461Distribution format: tar.gzProgramming language: C++Computer: Most Unix workstations and PCOperating system: Most Unix systems, Linux and windows, provided the ROOT package has been installed. Examples where tested under Suse Linux and Windows XP.RAM: Depends on the size of the MCNP output file. The example presented in the article, which involves three two-dimensional 139×740 bins histograms, allocates about 60 MB. These data are running under ROOT and include consumption by ROOT itself.Classification: 17.6External routines: ROOT version 5.24.00 (http://root.cern.ch/drupal/)Nature of problem: The output of an MCNP simulation is an ASCII file. The data processing is usually performed by copying and pasting the relevant parts of the ASCII file into Microsoft Excel. Such an approach is satisfactory when the quantity of data is small but is not efficient when the size of the simulated data is large, for example when time-energy correlations are studied in detail such as in problems involving the associated particle technique. In addition, since the finite time resolution of the simulated detector cannot be modeled with MCNP, systems in which time-energy correlation is crucial cannot be described in a satisfactory way. Finally, realistic particle energy deposit in detectors is calculated with MCNP in a two-step process involving type-5 then type-8 tallies. In the first step, the photon flux energy spectrum associated to a time region is selected and serves as a source energy distribution for the second step. Thus, several files must be manipulated before getting the result, which can be time consuming if one needs to study several time regions or different detectors performances. In the same way, modeling counting statistics obtained in a limited acquisition time requires several steps and can also be time consuming.Solution method: In order to overcome the previous limitations, the MODAR C++ code has been written to make use of CERN's ROOT data analysis software. MCNP output data are read from the MCNP output file with dedicated routines. Two-dimensional histograms are filled and can be handled efficiently within the ROOT framework. To keep a user friendly analysis tool, all processing and data display can be done by means of ROOT Graphical User Interface. Specific routines have been written to include detectors finite time resolution and energy response function as well as counting statistics in a straightforward way.Additional comments: The possibility of adding tallies has also been incorporated in MODAR in order to describe systems in which the signal from several detectors can be summed. Moreover, MODAR can be adapted to handle other problems involving two-dimensional data.Running time: The CPU time needed to smear a two-dimensional histogram depends on the size of the histogram. In the presented example, the time-energy smearing of one of the 139×740 two-dimensional histograms takes 3 minutes with a DELL computer equipped with INTEL Core 2.     

A system for multibody analysis based on object-relational database technology

An efficient support for computational technology and information management will be critical in future Engineering Information Systems (EIS). This paper shows how it is possible to provide efficient data management capabilities to the discipline of Multibody System (MBS) analysis. The MECHAMOS prototype of a MBS analysis tool has been developed that is based on an object-relational database management system, AMOS, which has been extended with additional mathematical functionality by the use of Matlab and MapleV as computational engines. The MBS model is represented as a database model in AMOS and the analysis is based on symbolic formulation of Kane's equations of motion. With this configuration, data is made fully accessible via the AMOSQL query language of AMOS. Furthermore, by providing the MBS application with general database technology, the data management will be more efficient in terms of handling large amounts of data and the development and maintenance of MBS analysis systems. Since MBS models are represented in a “neutral format”, the reusability of these models increases and they will be more persistent to changes in the EIS environment.     

Object-oriented and distributed approach for programming robotic manufacturing cells

Flexible manufacturing systems (FMS) are essential for small/medium batch and job shop manufacturing. These types of production systems are used to manufacture a considerable variety of products with medium/small production volumes. Therefore, the manufacturing platforms supporting these types of production must be flexible and organized in flexible manufacturing cells (FMC). Programming FMCs remains a difficult task and is an actual area of research and development. This paper reports an object-oriented approach developed for FMC programming. The work presented was first thought for application in industrial robot manipulators, and later extended to other FMC equipments just by putting the underlying ideas in a general framework. Initially, the motivation for this work was to develop means to add force control to a standard industrial robot manipulator. This problem requires remote access to the robot controller, remote programming and monitoring, as also is required to program and monitor any other FMC equipment. The proposed approach is distributed based on a client/server model and runs on Win32 platforms, i.e., Microsoft Windows and Windows NT. Implementation for the special case of industrial robot manipulators is presented, along with some application examples used for educational, research and industrial purposes.     

基于XML的要素建模技术在地形图生产中的应用研究

基于Bentley最新的要素建模技术,全面阐述了该技术的属性和方法、PBS和PBA等面向对象的概念及其在地形图生产中的应用。以地形图中房屋要素的制作为例,并同早期基于MGE平台下的地形图生产方法或技术进行了详细地比较,系统分析了该技术的优点。应用实践表明：该技术不仅大大提高了基础地形图的生产效率,而且较好地实现了基础地理数据GIS和CAD的一体化管理。     

基于Unix实现的类OLE组件技术及其在电网调度自动化系统中的应用

组件技术已引起软件开发模式的巨大变革，它也必将促进电网调度自动化平台软件的进步。由于在Unix平台上还没有类似于OLE能支持图形对象的组件技术，作者在Unix平台上利用C 将Motif/Xt封装成面向对象的Motif开发包，据此实现了类似OLE的技术，并将该技术应用于电网调度自动化系统中，开发了新型电网调度自动化支撑平台。     

冷冲模CAD中面向对象技术的应用研究

介绍了软件工程领域的技术同实际应用相结合的具体方法，面向对象技术是当今的主流软件开发方法，它具有封装性、继承性和多态性。文中讨论了面向对象技术的封装性和多态性在冷冲模CAD系统中的应用，分析他们在提高系统可扩充性、降低系统复杂度方面的作用，并举例分别加以说明。