复杂参数产品形态设计中的解空间降维方法

针对产品形态设计中评价标准的模糊性问题,探索了智能化设计方法中的操作性技术.基于产品的形态编码,采用参数权重集中曲线的噪声度自动评测方式对解空间进行降维处理,并对产品形态编码分级.在降维后的系列解空间中使用交互式遗传算法搜索最优方案,并逐级完成形态的细化设计.文中方法从用户交互选择信息中提取出各参数对产品形态的重要性等级,作为细化设计过程的依据.求解过程全部基于解码的形态方案进行,为设计师的工作提供了直观的界面.     

天喻三维设计绘图系统

一、产品概述天喻三维设计绘图系统是一个优秀的产品造型与设计系统。采用面向对象技术和先进的几何造型器ACIS,面向用户的设计意图,通过零件造型、装配设计和工程图的生成来满足产品设计与造型的需要。二、主要特点1．基于最先进的几何造型器ACIS基于ACIS,同时能方便地与基于其他几何造型器的CAD系统进行数据交换。2．在设计与造型过程中体现并维护用户的设计意图InteSolid将设计意图的捕捉和维护变得异常简单。3．基于设计过程的产品设计与造型用户可以调整设计过程,以使产品外形发生相应的变化,而不必进行重新设计。4．界面…     

计算机辅助造型设计支持系统建构方法研究

本文基于产品造型现状进行分析,通过计算机辅助设计与产品功能类型相结合造型理论的观点,对产品设计方法的计算机辅助支持系统进行解析,通过调查影响产品设计的因素以找到最适合的产品形象,创造一个定性的图像数据库,文章通过分析产品造型设计的元素,形成数据库建模,然后进行定量分析,对应关系图像之间的有利于实现产品的成型,从而构建了一个基于知识的产品造型设计.最后,经验证和实际应用以证明该方法是合理可行的.     

基于参数化符号学的航天文创产品设计探究

文章基于参数化符号学的设计方法,通过解析参数化符号学,分析航天文创产品设计中的文化融入,提出文创产品设计的参数化符号学解读模型,为航天文创产业发展提供参考。文章运用参数化符号学对航天文创产品从语义、语构、语境三个维度进行解析,并从外延语义、内涵语义、构成法则等角度对航天文化元素进行整合分析。通过参数化符号学对航天文创产品的设计分析,探讨航天文创产品的参数化符号学价值与构成,产品设计的传达过程与编码规则,以促进航天文化融入现代设计中,提升产品内涵价值,推进航天文化的传承与发展。     

InteSolid

一、产品概述 ＩｎｔｅＤｏｌｉｄ是一个优秀的产品造型与设计系统。采用面向对象技术和先进的几何造型器ＡＣＩＳ,面向用户的设计意图,通过零件造型、装配设计和工程图的生成来满足产品设计与造型的需要。 二、主要特点 １．基于最先进的几何造型器ＡＣＩＳ 基于ＡＣＩＳ,同时能方便地与基于其他几何造型器的ＣＡＤ系统进行数据交换。 ２．在设计与造型过程中体现并维护用户的设计意图 ＩｎｔｅＳｏｌｉｄ将设计意图的捕捉和维护变得异常简单。 ３．基于设计过程的产品设计与造型 用户可以调整设计过程,以使产品外形发生相应的变化,而…     

基于图解特征语义认知的产品设计过程知识模型

针对产品造型设计过程知识表征,提出基于图解语义认知的产品设计过程知识模 型。分析产品的本体语义及产品设计过程知识,结合可拓学基元理论构建产品设计过程的知识 表征基元模型,提出可拓原点基元及可拓向量概念,实现设计过程--设计生长、设计收敛及 设计优化的知识表征。在产品设计过程知识基元表征模型基础上,提出基于图解语义的实例库 聚类方法模型。以机床装备造型设计为例,验证了该方法的可行性,为产品造型设计提供一种 形式化与量化相结合的设计参考方法。     

参数化设计研究

参数化设计是提高企业产品设计创新能力的关键。从参数化模型的不同表示方式，相应的求解方法，建立模型的交互手段等方面综述产品参数化设计的研究现状及未来发展中需要解决的问题。重点讨论传统CAD领域所涉及的二维图纸及三维零件造型等几何问题参数化设计，并在此基础上对传统的参数化的概念进行扩展，讨论产品全生命周期的参数化设计问题及产品参数化设计的相关国际标准。     

基于人物角色的产品用户需求获取方法研究

为了使产品设计能深入满足用户的真实需求,在设计开发前期有效准确获取用户需求就变得十分关键。提出了一种基于人物角色模型的产品用户需求获取的新方法。通过场景细分确定典型用户,结合5W2H法提炼构建用户人物角色模型,通过KJ法对人物角色模型中提炼的用户需求进行聚类,得到典型用户需求指标体系。使用改进后的主观赋权法确定参数的权重,加权各方案并比较最终确定用户需求。并以无线移动终端产品造型设计为例进行说明。     

CAE在仪表产品造型设计中一体化的应用

在分析仪表产品虚拟原型逼真设计思想的基础上,结合仪表产品造型设计系统的开发工作,利用3D软件I-DEAS作为开发平台,对CAE在仪表产品造型设计中的一体化技术进行了研究.借助计算机分析计算模拟实验方案,为快速实现基于虚拟原型逼真设计的仪表产品造型设计、提高产品设计质量、缩短设计周期,提供了快捷可行的方法.     

产品造型设计多阶段网络耦合决策方法研究

为综合考虑产品造型设计多阶段决策信息,引入复杂网络理论,提出了产品造型设计多阶段网络耦合决策流程.对产品造型设计多阶段决策关系进行了耦合关联建模,基于对决策者评分的一致性分析确定设计决策网络的邻接矩阵,依据网络凝聚度变化获得决策者权重,以设计决策网络凝聚度的稳定性和决策者意见一致性确定决策轮次,构建规划函数计算产品造型设计决策各阶段权重,通过线性耦合实现多阶段决策信息集结.以数控磨床造型设计决策为例验证了方法的有效性,结果表明所提方法能够实现产品造型设计多阶段决策信息的集结,提高设计决策的全局性和科学性.     

An automated coding and classification system with supporting database for effective design of manufacturing systems

The philosophy of group technology (GT) is an important concept in the design of flexible manufacturing systems and manufacturing cells. Group technology is a manufacturing philosophy that identifies similar parts and groups them into families. Beside assigning unique codes to these parts, group technology developers intend to take advantage of part similarities during design and manufacturing processes. GT is not the answer to all manufacturing problems, but it is a good management technique with which to standardize efforts and eliminate duplication. Group technology classifies parts by assigning them to different families based on their similarities in: (1) design attributes (physical shape and size), and/or (2) manufacturing attributes (processing sequence). The manufacturing industry today is process focused; departments and sub units are no longer independent but are interdependent. If the product development process is to be optimized, engineering and manufacturing cannot remain independent any more: they must be coordinated. Each sub-system is a critical component within an integrated manufacturing framework. The coding and classification system is the basis of CAPP and the functioning and reliability of CAPP depends on the robustness of the coding system. The proposed coding system is considered superior to the previously proposed coding systems, in that it has the capability to migrate into multiple manufacturing environments. This article presents the design of a coding and classification system and the supporting database for manufacturing processes based on both design and manufacturing attributes of parts. An interface with the spreadsheet will calculate the machine operation costs for various processes. This menu-driven interactive package is implemented using dBASE-IV. Part Family formation is achieved using a KAMCELL package developed in TURBO Pascal.     

MODIS土地覆盖数据产品精度分析——以黄河源区为例

MODIS土地覆盖数据产品覆盖广、时间分辨率高,是区域土地覆盖变化监测的重要数据源。本文以中国土地资源分类系统为依据,重新归类黄河源区MODIS土地覆盖数据。利用2000年和2006年黄河源区Land-sat解译数据为参考数据,对相应的MODIS土地覆盖数据,从数量精度和形状一致性两个方面进行精度分析和适用性评价。结果表明:在形状上,加入权重的总体形状一致性皆在69%以上,其中主要地类草地的一致性达到88%以上;在数量上,加入权重的总体面积相对误差在26%以内,误差主要产生在未利用土地等地类。MODIS土地覆盖数据产品在大尺度的土地覆盖监测中仍然有重要的应用价值。     

Multiresolution HVS and statistically based image coding scheme

In this paper a novel multiresolution human visual system and statistically based image coding scheme is presented. It decorrelates the input image into a number of subbands using a lifting based wavelet transform. The codec employs a novel statistical encoding algorithm to code the coefficients in the detail subbands. Perceptual weights are applied to regulate the threshold value of each detail subband that is required in the statistical encoding process. The baseband coefficients are losslessly coded. An extension of the codec to the progressive transmission of images is also developed. To evaluate the performance of the coding scheme, it was applied to a number of test images and its performance with and without perceptual weights is evaluated. The results indicate significant improvement in both subjective and objective quality of the reconstructed images when perceptual weights are employed. The performance of the proposed technique was also compared to JPEG and JPEG2000. The results show that the proposed coding scheme outperforms both coding standards at low compression ratios, while offering satisfactory performance at higher compression ratios.     

Retrieval of machine-printed Latin documents through Word Shape Coding

This paper reports a document retrieval technique that retrieves machine-printed Latin-based document images through word shape coding. Adopting the idea of image annotation, a word shape coding scheme is proposed, which converts each word image into a word shape code by using a few shape features. The text contents of imaged documents are thus captured by a document vector constructed with the converted word shape code and word frequency information. Similarities between different document images are then gauged based on the constructed document vectors. We divide the retrieval process into two stages. Based on the observation that documents of the same language share a large number of high-frequency language-specific stop words, the first stage retrieves documents with the same underlying language as that of the query document. The second stage then re-ranks the documents retrieved in the first stage based on the topic similarity. Experiments show that document images of different languages and topics can be retrieved properly by using the proposed word shape coding scheme.     

代价敏感参数动态寻优机制的行人检测算法

提出一种基于动态代价敏感参数寻优机制的行人检测算法。该算法引入代价敏感的支持向量机分类算法,通过设置代价敏感参数处理图像中行人与非行人样本数量间的非均衡问题。考虑到代价敏感参数值的选择对检测性能影响很大,提出一种基于T变异的混沌粒子群算法,同时融入混沌算法及T变异函数提高粒子的全局搜索能力,并以正负样本正确分类的最佳折中作为寻优原则,在代价敏感权重值的取值区域内对参数进行动态寻优。实验结果证明,代价敏感参数动态寻优机制的行人检测算法有利于提高检测精度。     

Smoothing rational B-spline curves using the weights in an optimization procedure

Freeform shape design is typically accomplished in an interactive manner and shapes generated by a computer are rarely immediately acceptable. The available techniques for any subsequent modifications depend on the chosen representation for the geometry. In many computer aided styling and design systems which use nonuniform rational B-splines (NURBS) for representation of geometry, the use of the weights as a shape control tool is very inadequately supported. In fact they are often hidden from the user and therefore remain unused. This paper investigates the possibilities of entering the weights in an automatic fairing process. In order to produce a curve with a more gradual change in curvature and the smallest deviation from its initial shape the perturbation of the weights is stated as an optimization problem. Examples of applications to automotive shape design are presented and discussed.     

QFD-based expert system for non-traditional machining processes selection

Selection of an optimal non-traditional machining (NTM) process for generating a desired feature on a given material requires the consideration of several factors among which the type of the workpiece material and shape to be machined are the most significant ones. This paper presents a quality function deployment (QFD) based methodology to ease out the optimal NTM process selection procedure. It includes the design of a QFD-based expert system that can automate the decision making process with the help of graphical user interfaces and visual aids. The developed expert system employs the use of a house of quality (HOQ) matrix for comparison of the relevant product and process characteristics. The weights obtained for various process characteristics are utilized to estimate an overall score for each of the NTM processes. Finally, if some of the NTM processes satisfy certain critical criteria, they are again compared with each other on the basis of their overall scores and the process having the maximum score is selected as the optimal choice.     

多模式3维视频形状编码

目的 具有立体感和高端真实感的3D视频正越来越受到学术界和产业界的关注和重视,未来在3D影视、机器视觉、远程医疗、军事航天等领域将有着广泛的应用前景。对象基3D视频是未来3D视频技术的重要发展趋势,其中高效形状编码是对象基3D视频应用中的关键问题。但现有形状编码方法主要针对图像和视频对象,面向3D视频的形状编码算法还很少。为此,基于对象基3D视频的应用需求,提出一种基于轮廓和链码表示的高效多模式3D视频形状编码方法。方法 对于给定的3D视频形状序列逐帧进行对象轮廓提取并预处理后,进行对象轮廓活动性分析,将形状图像分成帧内模式编码图像和帧间预测模式编码图像。对于帧内编码图像,基于轮廓内链码方向约束和线性特征进行高效编码。对于帧间编码图像,采用基于链码表示的轮廓基运动补偿预测、视差补偿预测、联合运动与视差补偿预测等多种模式进行编码,以充分利用视点内对象轮廓的帧间时域相关性和视点间对象轮廓的空域相关性,从而达到高效编码的目的。结果 实验仿真结果显示所提算法性能优于经典和现有的最新同类方法,压缩效率平均能提高9.3%到64.8%不等。结论 提出的多模式3D视频形状编码方法可以有效去除对象轮廓的帧间和视点间冗余,能够进行高效编码压缩,性能优于现有同类方法,可广泛应用于对象基编码、对象基检索、对象基内容分析与理解等。