基于逆向工程和粗糙集的协同设计领域本体构建方法

针对协同设计领域本体构建难的问题,建立了基于逆向工程和粗糙集的协同设计领域本体学习模型.通过对产品数据管理数据库进行数据库逆向工程,获取产品数据管理数据库的物理数据模型和概念数据模型,从中提取与产品信息和开发过程有关的实体信息.建立了关系数据库模式到本体的映射规则,并从中学习本体概念和概念之间的关系.同时,根据获得的实体信息从产品数据管理数据库中采集数据构建面向特定主题的知识库,并利用粗糙集理论从知识库所存储的数据中发掘更多的概念和隐含的语义信息.该协同设计领域本体构建方法可以继承企业已有的知识和经验,减少领域专家的依赖,提高本体构建效率,降低本体构建成本.     

面向多学科协同开发领域的集成建模方法

为实现复杂产品研发过程中不同学科的信息共享,消除系统集成、协同仿真和系统优化的障碍,提出了基于本体元模型的数字化样机构建方法.分析了基于本体元模型的多领域集成建模的可行性,利用统一建模语言的扩展模型构建了本体的元模型核心包;基于本体理论分析了复杂产品协同开发领域的概念及其关系,构建了多学科协同领域信息集成框架;基于本体元模型建立了涵盖产品定义信息、研发方法信息和研发流程信息的数字化样机模型,支持产品在研发过程中的多抽象层次演化、多粒度层次分解和多学科协调优化,控制复杂产品的整个研发过程.以有源相控雷达为例对所提方法进行了说明.     

基于本体的协同设计产品信息模型研究

在产品协同设计过程中,由于产品信息模型缺乏足够的语义描述,导致协同设计过程中语义级信息共享和互操作困难。本文提出了基于本体的产品信息模型,采用本体对产品信息进行描述,建立了基于语义的信息共享机制,使产品协同设计过程的语义级信息共享和互操作成为可能。最后给出了一个基于本体的产品信息模型的实例。     

基于公理设计与TRIZ的概念设计知识管理研究

产品概念设计具有高度创造性、知识密集性及须同其他设计人员进行信息交互的特点．．在这个动态集中,传统信息管理系统功能语义信息缺乏,设计过程与产品信息有效集成的能力不足,不能为设计过程提供足够的支持。本文提出一种面向产品开发过程的公理化本体模型,作为产品概念设计知识管理及集成设计平台的工具。作为设计结果的产品公理化本体模型,不仅在设计过程中表达了设计方案,更是产品设计知识的载体。通过构造基于TRIZ的本体创新模型,解决了公理模型解决设计冲突的不足,增强了在概念开发中的实用性,提高了产品开发的创新性。     

面向多学科优化的柴油机本体建模与应用

为解决柴油机产品多学科设计优化过程中的信息模型语义简单、信息无法继承与共享等问题,提出了面向多学科优化过程的柴油机本体模型建模方法。设计了柴油机本体和多学科设计优化本体的顶层结构模型,对建模对象的语义关系进行了分析,针对该模型的多域大结构特点,提出基于Tableau的一致性检查算法。为实现从企业产品数据库到所提模型之间的映射,提出基于语义对准的数据库与该模型的交互技术,实现了基于本体技术的产品数据库中信息集成与语义化操作。设计了柴油机产品多学科设计优化平台的体系结构,开发了原型系统平台,并在该平台上完成了语义检索和语义驱动的多学科优化应用实例,验证了所提技术与方法的有效性和可行性。     

工业设计中基于本体的产品族设计DNA

为满足用户对多样化产品的需求,解决工业设计中设计方案的大量生成问题,提出了基于本体的产品族设计DNA研究方法.阐述了工业设计本体论和产品族设计DNA概念,探讨了工业设计产品族本体知识、产品族没计DNA的遗传与变异规律、流程和关键技术.提出了工业设计产品族本体知识表示模型和产品族设计DNA遗传与变异模型.以眼镜设计为例,构建了基于本体的眼镜产品族设计DNA层次模型和计算机辅助眼镜三维造型设计系统软件.基于该系统可以实现眼镜产品设计的快速生成,并可与用户的感性意象设计评估相对应,提高眼镜开发设计的效率,验证了基于本体的产品族设计DNA理论体系.     

知识网格环境下客户协同产品创新知识共享研究

基于知识网格在整合知识资源方面的优势,分析了知识网格环境下客户协同产品创新知识共享的特征,提出了知识共享模型,并对其关键研究点进行了深入研究。通过提出"创意-问题-功能"模型实现创新主体非结构化创意知识的转化;创建产品创新知识共享概念本体并定义其上下位关系;在对知识共享概念本体按概念型、规则型和实例型划分的基础上,提出一种基于OWL的产品创新知识本体语义表示方法;建立了知识共享的访问机制和原型系统,并通过某型号手持电钻的产品创新设计验证了所提出模型与原型系统的有效性和可行性。     

基于Web产品数据管理技术研究

基于Web技术分析了产品数据管理系统设计的特点和要求，提出了在分布式协同设计环境下的产品数据管理系统的体系结构和构造原型，引入基于本体的知识表示方法建立产品信息模型，实现了基于Web的产品数据管理系统(WBDCo-PDMS)。     

基于产品族实例本体模型的产品配置方法研究

为解决大规模定制环境下现有的实例配置知识表达方法可扩展性差、配置效率低的问题,将本体和产品族的概念与配置实例相结合,建立了基于本体的产品族实例模型.在分析模型的基础上,证明了产品族实例的本体表达有助于对配置问题语义信息的理解.同时,采用Web本体描述语言对概念实体及实体之间的关系进行了描述.以上述工作为基础,构建了摩托车产品族实例本体框架,从实例特征参数、实例配置知识及经验和实例配置方案三方面出发,对提出的模型进行了验证.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.