分布式协同设计的系统框架模型构建

研究了基于Internet／Intranet协同设计的系统架构：描述了异域异构分布式协同设计的结构模型、环境模型、过程模型与集成模型，为集成区域性或行业性制造业的分布式异构环境，构建了开放的、基于标准协议基础的协同设计框架。     

协同设计过程中产品模型协同批注的研究

面向分布式异构环境下的协同设计,分析协同设计过程中产品模型的协同批注流程,提出一套基于Web的产品模型异步协同批注解决方案,建立了异步协同批注系统的功能模型,并对该系统进行具体实现.通过共享模型技术,解决由不同三维设计建模系统所引起的批注过程中的异构问题,为分布式异构环境下协同设计的实现提供保障.     

基于计算机支持的协同工作的注塑模协同设计研究

协同设计是计算机支持的协同工作 (CSCW)在制造业中的重要应用。本文提出了基于 CSCW的注塑模协同设计系统 ,其采用的基于三级客户 /服务器原理的协同设计系统结构 ,可以有效支持异地异构分布式设计环境。同时对注塑模协同设计过程控制、协同设计产品多模型视图和基于多 Agent的协同组织机制进行了深入探讨。     

基于多组件智能体的机械产品协同设计集成方法

针对机械产品分布式异构环境下协同设计的特点，在定义组件智能体模型的基础上，提出基于多组件智能体的异构设计环境集成方法。采用“积木式”组合方式，构造了一个公共的集成框架。其特点是通过组合不同的组件智能体模块进行快速系统集成，同时使各个组件智能体之间可以进行通讯和协同，并共享产品的信息资源。所研制的集成框架可方便地构造一个机械产品设计项目，并在水泵网络协同设计中得到了应用验证。     

协同开发环境中项目管理与工作流管理的集成

通过对分布式协同产品开发过程管理的需求分析，结合分布式项目管理系统和工作流管理技术，提出了一种适用于协同产品开发环境的层次化过程管理模式。给出了项目管理系统与工作流管理系统的集成框架，通过共享数据库的方式和对任务模型及其结构的设计研究，实现了分布式项目管理系统与工作流管理系统的信息集成和功能集成，为实现异构、自治、分布的协同产品开发环境中的过程管理提供了有力支持。     

协同集成设计环境的计算机辅助工具的协同用户界面研究

以一个协同集成设计环境的计算机辅助工具为背景，对协同用户界面进行探讨。按照以群体为中心的协同用户界面的设计思想，提出了一种基于Agent的协同用户界面模型，把通讯和协作支持等并行处理的概念和方法引入到现有结构化模型之中。对比传统CAD交互结构，构造了一种支持上述用户界面模型的软件Agent结构。     

虚拟样机多学科协同设计与仿真平台实现技术

在分析产品协同开发平台的功能框架以及主要协同模式的基础上，深入研究了虚拟样机多学科协同设计与仿真平台的分布式计算模型，及其协同运行管理、协同产品开发资源库管理、分布数据的协同交互管理与系统实现技术。基于COM／DCOM的建模与仿真工具协同、支持仿真联邦管理的数据库设计和CORBA的应用实现技术，开发了原型系统。该系统支持Internet网络环境下各种建模与仿真工具跨平台、分布交互与异构集成，可有效支持复杂产品虚拟样机的协同开发。     

XVL及其在机械产品协同设计中的应用

基于网络的协同设计对异构三维数据的一致性转换和快速传输提出了更高的需求,但传统的基于产品模型数据交换标准STEP和基于虚拟现实建模语言VRML的解决方法,应用效果并不令人满意.为了更好地满足这种需求,提出将可扩展的虚拟世界描述语言XVL引入机械产品协同设计,并概述了其技术特点及数据转换技术.基于XVL三维数据共享模型库构建了面向企业集成应用的系统体系结构,提出了基于XVL的协同设计管理系统模型,最后开发了一个机械产品在线网络协同设计管理原型系统.     

基于Samba的异构环境协同设计文档传输模型研究与应用

如何有效解决在操作系统异构情况下协同设计文档的传输与共享 ,是协同设计研究的一项重要基础性问题。在分析协同设计异构性问题的基础上 ,本文介绍了Samba技术原理及其应用 ,提出了基于Samba的异构环境协同设计文档传输模型 ,描述了模型的协同及访问控制机制 ,以及传输管理器和文档管理器的设计方法 ,并给出了该模型的应用实例。     

分布式虚拟设计环境中多用户协同设计研究

虚拟设计已成为制造业发展的重要方向 ,而基于网络的分布式虚拟设计为多用户共同参与虚拟设计提供了条件。考虑到分布式虚拟设计对计算机的计算能力和实时显示的要求及对网络带宽的要求 ,作者设计了分布式虚拟设计结构 ,该结构能为多用户共同参与设计提供虚拟设计环境。为了使设计人员进行有效的协同设计 ,作者应用分布式人工智能的思想为多用户协同设计提供了多用户协同设计模型以及当发生冲突时的决策模型     

割草机刀片不同刀刃角度对刀盘内流体的影响

刀片高速运转时,在刀片后部会形成各种涡,从而影响割草机的工作效果。使用FLUENT软件对刀盘内气流进行模拟,在其余条件相同的情况下,随着刀片角α的增大,刀片后部的涡及刀片运动带起的气流运动上升趋势增大,刀片吸引草叶的能力更大。随着刀片角γ的增大,气流上升运动也加大。然而,当γ=5°的时候,可以发现刀片前段下方的涡有减弱的趋势,当γ=10°的时候,涡的现象又增多,同时增大刀盘流场中湍流的可能性,湍流会降低割草机工作效率。最终确定相对有利的刀片刃角和安装角为α在35°～45°之间,γ=5°左右的组合。     

Embryonic erythropoiesis in human yolk sac: two different compartments for two different processes

The wall of 12 yolk sacs (YSs) from 17- to 50-day-old human embryos was examined by light, scanning, and transmission electron microscopy to identify the ontogeny of embryonic erythropoiesis. Initial formation of blood island with the generation of erythroid and endothelial cells was seen in the mesenchymal layer in embryos aged 17 days. A network of blood vessels containing abundant erythroblasts was identified in the YS walls of embryos aged approximately 24 days. At this age, erythroblasts were also identified within the embryo body. Primitive erythroblasts were the only cells present within the embryo and its YS until the end of week 5. These cells first appeared in the mesenchymal vascular plexus of the YS wall, and were then observed in the liver and other tissues of the embryo. At embryonic week 5, two compartments were identified in the YS wall; a mesodermal one in which blood vessels were formed, and an endodermal compartment in which erythrocytes were present within the endodermal vesicles. Erythrocytes were small non-nucleated cells similar to adult erythrocytes. Transmission electron microscopic observation focused on the endodermal vesicles confirmed the presence of definitive erythrocytes only at such extra vascular location. At this age, there were no definitive erythrocytes detected within the embryo. Erythrocytes started to be identified in embryonic blood vessels from week 7 onward. These findings provide information not previously described about YS erythropoiesis during early human development.     

Comparison between two different methods for evaluating rumen papillae measures related to different diets

Although the Geographical Information System (GIS), which integrates computerized drawing computer assisted design (CAD) and relational databases (data base management system (DBMS)), is best known for applications in geographical and planning cartography, it can also use many kinds of information concerning the territory. A multidisciplinary project was initiated since 5 years a multidisciplinary study was initiated to use GIS to integrate environmental and ecological data with findings on animal health, ethology, and anatomy. This study is chiefly aimed at comparing two different methods for measuring the absorptive surface of rumen papillae. To this scope, 21 female sheep (Ovis aries) on different alimentary regimes (e.g., milk and forage mixed diet, early herbaceous diet, dry hay diet, and fresh hay diet at the maximum of pasture flowering and at the maximum of pasture dryness) were used; after slaughtering, 20 papillae were randomly removed from each sample collected from four indicator regions of rumen wall, placed near a metric reference and digitally photographed. The images were developed with the ArcGIS? software to calculate the area of rumen papillae by means of GIS and to measure their mid‐level width and length to calculate the papillae area as previously performed with a different method. Spatial measurements were analyzed using univariate and multivariate methods. This work demonstrates that the GIS methodology can be efficiently used for measuring the absorptive surface of rumen papillae. In addition, GIS demonstrated to be a rapid, precise, and objective tool when compared with previously used method. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Material response at different strain-rates

Mechanical response of materials under various strains and strain-rates is important for analysis of metal forming processes and structures. This paper presents a brief review of various testing methods and some experimental results     

What's different about Six Sigma?

The Six Sigma approach is one of the more recent initiatives adopted by organisations who seek to make a paradigm shift in performance improvement (attacking at least one of the cost, quality, delivery measurements for improved competitiveness). Is there anything new about Six Sigma, does it offer improvements that other approaches cannot, or is it just a clever delivery of repackaged goods? The author investigates the above questions related to the Six Sigma approach