基于格网的交叉口立面设计软件开发

交叉口立面设计的计算绘图工作量大,需用CAD提高效率。提出了交叉口设计单元划分和基于点、线、面的几何建模方法。采用格网作为三维设计面,讨论了相应的设计流程和算法。依托AutoCAD平台和ObjectARX开发技术,阐明了设计要素的表达方式,用C++编程实现了软件功能。结果表明,所采用的几何建模方法适用于各种形式的交叉口,基于格网的三维设计高效直观,利用ObjectARX能方便地实现软件功能。     

隧道结构设计的数值模拟与类比设计

本文探讨了隧道结构设计的理论和方法，并指出了隧道洞门和衬砌结构都是主体工程，不能轻此重彼；建立隧道工程数据库，可以从纵观全局的基础上确定出经济合理的设计方案；要从本质上做到甩掉图板，加大隧道专业ＣＡＤ辅助制图软件的开发势在必行。     

基于OpenGL的三维服装CAD中光照技术的实现

介绍了OpenGL及其与VC.NET的接口技术.在光照理论及其数学模型的基础上,借助UML建模语言,详细阐述了利用OpenGL开发工具包实现三维服装CAD中灯光照射效果的全过程,最后展示了不同角度对人体模型的光照效果.     

基于三维CAD中望3D高效创建五金水槽模型

以前用二维CAD创建不锈钢盆体三维模型,不但过程复杂,而且异形盆体模型的中心线或中心点位置很难捕捉,特别是异形盆体中心和落水口的中心往往不能保证处于同一中心位置,总是有偏差。另外,还需要根据配套产品、制造工艺和市场需求反复修改,直至符合审核标准。中望3D作为一款拥有全球自主知识产权的工业级三维CAD／CAM软件,在三维模型设计方面更有优势,中心位置和自动捕捉更加方便精准。采用中望3D三维CAD软件,以中心线或中心点为基准便能轻松高效创建水槽模型。     

Endothelial Nitric Oxide Synthase (eNOS) 4b/a Gene Polymorphisms and Coronary Artery Disease: Evidence from a Meta-Analysis

A variety of studies have suggested that the 4b/a polymorphism in the endothelial nitric oxide synthase (eNOS) was associated with coronary artery disease (CAD) risk. However, the data remain conflicting. The aim of the present meta-analysis was to estimate the overall association between risk of CAD and eNOS 4b/a polymorphism. Case-control, cohort or cross-sectional studies evaluating the association between eNOS 4b/a polymorphism and CAD susceptibility were systematically identified in PubMed up to 31 October 2013. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were calculated to assess the association in overall and subgroup analyses. A total of 10,617 cases and 8302 controls from 37 studies were included in the study. The results of overall analysis revealed significant positive associations between CAD risk and eNOS 4b/a polymorphism in homozygote comparisons (OR = 1.47, 95% CI = 1.16–1.87), heterozygote comparisons (OR = 1.14, 95% CI = 1.02–1.27) and dominant models (OR = 1.18, 95% CI = 1.06–1.33). In subgroup analyses, similar associations were identified in African individuals, as determined using population-based source subgroups and noted in small-and-moderate sample size subgroups (case sample size or control sample size <500). The current meta-analysis revealed that eNOS 4b/a polymorphisms could be a risk factor for developing CAD, particularly in African populations and population-based subgroups.     

Novel method for transferring access control list rules to synchronize security protection in a locator/identifier separation protocol environment with cross‐segment host mobility

Extended access control lists (ACLs) are used to filter packets for network security. However, in current network frameworks, ACL rules are not transferred simultaneously with devices that move across network segments. The Internet Engineering Task Force proposed the Locator/Identifier Separation Protocol (LISP), which enables routers (xTRs) to configure ACL rules for blocking immobile endpoint identifiers (EIDs). However, when an EID moves from the original xTR to a new xTR, the ACL rules at the original xTR cannot be transferred with the EID. Thus, the new xTR lacks the corresponding ACL rules to effectively block the EID, resulting in security risks. The highlights of this study are as follows. First, a method is proposed for dynamically transferring ACL rules in LISP environments and frameworks. Second, the map‐register and map‐notify protocols were combined to encapsulate and transfer the ACL rules and thus obviate an additional process required to transfer these rules. Third, the experimental results verified that the proposed method can be used to achieve synchronized security protection in an LISP environment involving cross‐segment EID movements.     

CAX技术及其集成研究综述

在对现有CAX技术及其集成技术进行研究的基础上,首先介绍了各种CAX技术的概念、工作过程、应用现状和主要应用软件等,并分析了CAX集成技术的框架和工作流程,最后探讨了CAX技术及其集成的发展方向。     

A bill of materials-based approach for end-of-life decision making in design for the environment

Re-use, recycling or remanufacturing of products and components are good alternatives for reducing the environmental problems resulting from the huge amounts of waste currently arriving at landfills. A new approach is proposed in this paper for enhancing these alternatives from the earliest stages of product design. Given the product structure (obtained from its bill of materials (BOM)) and the joining and geometrical relationships among the components (obtained from the three-dimensional, computer-aided design representation), a model is proposed that will determine the EOL (EOL) strategy, i.e. the depth of disassembly inside the structure and the final end (re-use, recycle, remanufacture or disposal) for each disassembled part leading to the highest profit. A scatter search (SS) metaheuristic is used to determine the disassembly cost at each level of the BOM. The model presents a number of major improvements with respect to previous research. It addresses the problems of simultaneously determining both the best EOL strategy and the disassembly sequence, as well as allowing removal of components not only over the two or three Cartesian axes and affording the possibility of modifying the encountered strategy in a further step so as to fulfil other business criteria (such as disassembly time, resources availability or maximum waste generation rate).     

From regional sensitivity to intra-sensitivity for parametric analysis of free-form shapes: Application to ship design

Robust Parametric Sensitivity Analysis (PSA) is a prerequisite for efficient shape optimisation via parametric modelling. A major challenge PSA has to handle is related to the fact that a parameter can be sensitive in certain local areas of the design space but become insensitive in others. Therefore, setting an applicable space for this analysis becomes a difficult task. In this paper, we introduce the concept of intra-sensitivity to identify parameters whose perturbation has a major impact on the sensitivity index of the remaining parameters. For this purpose, we firstly appeal to Active Subspace Method (ASM) and develop an ASM-based regional sensitivity analysis, which investigates parametric sensitivity in local regions of the design space and aids conducing to parameters’ intra-sensitivity. This regional analysis is applied in conjunction with a Dynamic Propagation Sampling approach, for tackling the computational complexity arising when high-dimensional problems are concerned. Once sensitive and intra-sensitive parameters are identified, then free-form features, correlated to these parameters, are evaluated using a feature saliency map built with the aid of Hausdorff distance. The so resulting methodology has been validated in the area of computer-aided ship design using two parametric modellers: the first one is a Procedural Deformation (PD) modeller which is based on T-splines and involves 24 parameters while the second one is based on Free-Form Deformation (FFD) and involves 104 parameters. The corresponding design spaces have been generated using a parent hull close to the KCS container ship and are analysed against hull’s volume of displacement and total resistance. Finally, the convergence performance of the various components of this approach is compared with state-of-the-art techniques.