基于2PLM项目参数估计的病态矩阵控制

病态矩阵是IRT理论中项目参数估计必然面对的问题．本文以2PLM参数估计为例．推导出参数估计迭代公式，系统阐述了三种病态控制方法的原理及在编程中数据处理的技巧。     

The materials and techniques used in the paintings of Francis Bacon (1909–1992)

Abstract

Materials from 38 paintings by Francis Bacon (1909–1992), including 21 complete works and 17 partially destroyed canvases are investigated. Observations are made of the artist's technique and details are compiled of the supports used. Samples of paint and priming were taken for analysis using polarized light microscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), pyrolysis–GC–MS (Py–GC–MS), and scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM–EDX). Analysis of priming layers appears to show that the priming composition correlates well with particular ranges of dates. A fairly limited range of materials are found, with many of the same pigments found in works spanning Bacon's career, though other pigments were introduced at different stages in his career. Oil paints were used consistently for the painting of figures, but household paints were increasingly used in backgrounds from the 1960s onwards. A variety of different synthetic media are found in later works, including household acrylic paints and spray paints. Increased knowledge of Bacon’s materials is expected to be of great value to conservators caring for the work of this highly significant artist, and is already helping in the authentication of works attributed to him.     

支持大规模定制的PLM技术

大规模定制时代已经到来,目前企业面临的最大挑战是产品的成本和交货期。在产品全生命周期管理PLM技术的支持下,产品的设计成本会显著降低,开发周期也会明显缩短。同时在协同产品商务的平台上,通过与客户关系管理、供应链管理及企业资源计划的集成,PLM技术有助于企业实现产品的快速制造和配送,最终满足用户的个性化需求。     

Investigation of the materials found in the studio of Francis Bacon (1909–1992)

Abstract

The investigation of materials found in Bacon's studio is reported. The contents of the studio are examined and interpreted to identify the materials and colours most favoured by Bacon, and the range of media used. A small number of colours appear to have been heavily used. Some objects used as tools in the painting process are also investigated and explain textures seen in paint in his works. Samples of selected materials from the studio are analysed to identify the components of paints (pigments, extenders, and binders) used by Bacon. This investigation is part of a wider project examining his materials and techniques. The analytical information obtained here from the studio helps to clarify the statements made by Bacon in interviews regarding his use of materials and is proving useful in the identification of materials in his paintings, in order to help with the conservation and authentication of his works.     

On the integration of model-based feature information in Product Lifecycle Management systems

As CAD models continue to become more critical information sources in the product’s lifecycle, it is necessary to develop efficient mechanisms to store, retrieve, and manage larger volumes of increasingly complex data. Because of their unique characteristics, 3D annotations can be used to embed design and manufacturing information directly into a CAD model, which makes models effective vehicles to describe aspects of the geometry or provide additional information that can be connected to a particular geometric element. However, access to this information is often limited, difficult, and even unavailable to external applications. As model complexity and volume of information continue to increase, new and more powerful methods to interrogate these annotations are needed.In this paper, we demonstrate how 3D annotations can be effectively structured and integrated into a Product Lifecycle Management (PLM) system to provide a cohesive view of product-related information in a design environment. We present a strategy to organize and manage annotation information which is stored internally in a CAD model, and make it fully available through the PLM. Our method involves a dual representation of 3D annotations with enhanced data structures that provides shared and easy access to the information. We describe the architecture of a system which includes a software component for the CAD environment and a module that integrates with the PLM server. We validate our approach through a software prototype that uses a parametric modeling application and two commercial PLM packages with distinct data models.     

UG在我国的研究、应用现状及进展

文幸运用文献计量学方法,以"中国知识资源总库"等国内权威的大型数据库为依据,利用追溯法等检索方法,利用数理统计方法对有关UG研究的学术论文进行统计分析,以此来评析UG在我国的研究、应用现状及进展等.     

成功实施PLM项目的关键要素

Product Lifecycle Management (PLM) is a business strategy beginning to gain wide acceptance. Concerning the implementation of PLM projects, six success factors are presented and analyzed in details in this paper.     

基于CAXA PLM的数字化教学平台建设与实践教学应用

介绍了以我国自主研发的CAXA PLM为基础建立数字化协同设计制造教学平台的建设模式,以及借助该教学平台实施基于工作过程的模拟真实企业岗位角色的实践训练模式.     

集成产品创新开发研究

集成产品开发(IntegratedProductDevelopment,以下简称IPD)是一种关于产品开发的理念、思想和方法论,其核心思想是“市场导向,组织创新”,通过策略、组织、资源配置、流程、IT工具等管理要素的整合,建立面向市场和客户需求的、跨部门参与的集成产品开发流程,从而进行系统的、平衡的、高效的、有价值的组织创新,以缩短产品开发周期,降低产品生命周期成本,提升产品质量和客户价值。本文结合我国企业产品开发的特点和典型问题,从产品开发战略、产品开发组织、产品开发流程和IT工具四个方面简要介绍了思捷达IPD的基本内容。     

MDA模型转换的研究

以PLM系统(Product Life Cycle Management,产品生命周期管理)的研究开发为背景,对该系统中的采购管理模块进行了基于UML的PIM模型的建立,并结合MDA开发模式,分析设计了从平台无关的PIM到与EJB平台相关的PSM之间的转换,具有较强的软件工程实践的意义.