云制造平台资源需求的高效匹配策略研究

为快速、精确地从云制造平台资源池中搜索到满足用户需求的资源,实现资源与需求的高效匹配,提出了一种资源需求高效匹配策略。首先,建立了资源与需求的形式化描述模型,在此基础上,采用改进的K-means聚类算法按基本信息进行聚类,对云服务池中的资源进行预处理,形成多个资源簇;其次,计算用户需求与各资源簇聚类中心基本信息的相似度,确立备选资源簇;最后,再分别从资源的状态信息、功能信息和服务信息3个方面对备选资源簇中的备选资源进行筛选匹配。实例分析和研究结果表明:与已有的匹配方法相比,该方法在保持较高匹配精度的同时具有更高的匹配效率。     

基于混合任务网络的智慧制造任务协同分配模型

复杂任务场景下,由于制造子任务间存在多维的物料、信息、知识交互和传递关系,对匹配服务单元间的协同能力提出一致性要求,任务关系与服务协同关联匹配不精确将带来额外协调和交互成本,降低资源配置效率,而传统任务分配模型忽视任务关系约束对分配结果的影响。鉴于此,通过任务网络与服务协同网络的动态匹配,构建了面向任务关系约束的任务协同分配方法。针对"好钢未用在刀刃上"现象,综合用户偏好和网络中心性分配任务权重,提出基于权重的服务胜任度聚合方法;针对"1+12"不协同现象,提出基于横向协同和纵向协同的服务协同水平计算方法;综合考虑服务群体的胜任度和协同水平,提出基于混合任务网络的多目标任务分配优化数学模型。利用改进非支配粒子群算法进行求解得到Pareto最优解集,根据用户偏好和实际制造情形,通过加权TOPSIS评估获取个性化、灵活的最佳分配方案。运用汽车云制造仿真实验,验证了模型的有效性,通过在最好解、平均解和运行时间上与其他算法进行对比,分析了所提方法的优势。     

基于双链遗传算法的网络化制造资源优化配置

网络制造环境下合作伙伴的选择采用的主要方法是对被选企业的一些宏观信息进行评价,该方法无法保证在形成动态联盟后制造系统的运行效率,并且要求预先确定任务的分配,无法保证各个企业之间任务分配的合理性.针对这样的问题,从更底层的制造资源优化配置入手,研究制造资源如何在网络制造环境下优化配置,从而确定合作伙伴和各合作伙伴所需要承担的生产任务.任务分配涉及企业-资源-任务三者之间的匹配,使得原本就是NP难题的调度问题更加复杂,借鉴传统遗传算法和生物学进化原理,提出一种双链遗传算法来解决这样的规划问题,相对于传统遗传算法这样算法的效率更高,编码解码更容易,可以解决网络制造资源优化配置问题.     

面向服务链构建的云制造资源集成共享技术研究

为实现时序约束关联任务驱动的云制造环境下面向服务链构建的制造资源集成共享,研究并提出一种能促进云制造环境下制造资源快速共享、广域集成和分散服务特点的服务过程模型,对基于语义本体的云制造任务与资源建模、基于Web服务资源框架的云制造资源的平台服务化封装方案、云制造任务分解与时序约束关联原子任务链构建技术,以及云制造资源服务链构建技术等关键问题进行了研究,有效解决了云制造环境下异构资源描述、虚拟化、检索匹配与服务组合问题,最后通过仿真算例对提出的云制造服务模式及技术方案进行了验证。     

e-制造系统的制造资源动态配置过程研究

传统制造资源动态配置没有涉及制造系统、制造单元和设备之间制造过程信息的重组模型,据此,在拓展传统制造资源动态配置模型的基础上,结合模糊聚类理论,研究了e制造环境下制造任务在一定批量和多工艺方案情形下的单元化配置模型,以及基于此配置结果的制造系统、动态制造单元、设备间的信息重组模型与制造过程信息跟踪方法,为“柔性制造”、“数宁化精确生产”奠定了基础,并对开发的原型系统进行验证。     

一类制造资源的协同建模、优化与求解技术

为实现云制造环境下制造资源的全面共享、发现和匹配,提供给用户理想优质的云制造服务,在虚拟资源池构建阶段引入资源建模与聚类技术,提出一种适宜云制造模式的虚拟资源的建模与优化组合方法。采用基于可扩展标记语言数据与Web本体描述语言语义的双层模型,对云池的虚拟资源协同进行建模;建立基于服务成本、服务效率、服务质量和信誉度的多目标优化数学模型,采用协同多目标粒子群算法求解该优化问题,获得最优的虚拟制造单元。以生产实践中开发的原型系统为例,验证了所提方法能够有效提高云池虚拟资源的共享、发现和匹配性能,也验证了其在工程应用中的正确性。     

基于动态集成框架的云制造服务过程追溯与匹配研究

为有效控制制造资源虚拟化过程,考虑不同制造资源的形态,提出了云制造资源动态集成框架,研究了基于RFID的云制造服务过程追溯机制。在此基础上,建立了云制造资源服务能力多目标评价体系,并通过评价指标加权和计算云制造资源优先值,为制造任务匹配最优云制造资源节点。最后,结合云制造应用实例,验证了云制造服务动态集成体系的合理性和优选算法的可行性。     

云制造环境下基于离散Markov跳变系统的机床装备资源动态优选方法

针对云制造环境下加工任务执行过程中机床装备资源易受紧急插单、加工质量异常、设备运行故障等高频随机扰动影响,致使产品加工服务质量(QoS)不能满足客户个性化需求的问题,提出一种基于离散Markov跳变系统的机床装备资源动态优化选择方法.首先,结合云制造服务运行特点,构建了云制造环境下面向加工任务执行过程的服务质量动态演化...     

基于环境视频语义的云制造资源描述

针对云制造环境下各行业资源难以统一描述、资源云池内可用资源更新滞后、资源匹配计划执行力度弱等问题,提出一种显形表达资源动态变化的层次环境视频语义模型。该模型通过面向变化的三域(特征域-行为过程域-结果域)定义环境视频语义的层次结构和数据的层次表达,在各层次语义描述中将环境视频语义与视频内容语义有机结合,支持多地环境视频数据的关联表示,为后续云制造环境下资源匹配的动态实时、高效及可靠奠定了基础。     

云制造环境下资源动态调度系统研究

云制造环境下资源动态调度是云制造中的关键技术之一。针对云制造环境下制造资源调度的特点和存在的问题,提出了基于资源负载均衡的动态调度策略,建立了以完成任务的总服务成本最小为优化目标的模型,并通过建立应用实例说明了该系统的实际应用过程。     

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.     

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。     

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....     

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.