基于流程案例簇的任务关系挖掘算法

为了进行流程发现,提出一种基于流程案例簇的任务关系挖掘方法.该方法首先将基本案例按照特征向量分为多个案例簇,根据基本案例的任务轨迹对案例簇中任务间的依赖关系进行挖掘;然后给出了基于循环基元的循环结构建模和挖掘方法,最终可以从事件日志导出流程中完整的任务依赖关系以及存在的循环结构.所提方法能正确处理任务依赖关系随案例属性取值不同而变化的情况.只要日志完备,基于挖掘到的任务关系和循环结构就能得到一个与原流程行为等价的流程模型.     

一种基于滑窗的增量式过程挖掘算法

传统过程挖掘算法是针对静态模型和静态日志进行设计的,不能直接用于演化过程的发现.为此,提出了一种过程挖掘算法,应用滑窗机制实现增量式算法设计,利用日志事件关系模型,引入日志事件关系计数和阈值机制,实现对事件日志流的持续挖掘,因而能够发现模型演化的历史及模型当前实际执行情况.分析了算法性质及相关参数的影响,并进行了实验验证.     

基于依赖关联度的业务过程噪声日志过滤方法

日志中发生的低频次行为与挖掘的流程模型中某些不必要的结构相对应,而这些结构的出现会引起挖掘模型在适应度和精确度等指标上的下降。为解决这些结构对流程挖掘模型质量造成的影响,提出一种基于依赖关联度的噪声日志过滤方法。该方法首先根据日志中事件及其依赖关系的统计频率,定义了依赖关系的局部关联度和整体关联度,并将两者归一化为混合关联度来筛选出噪声日志。然后通过轨迹可达性分析去除日志中的噪声,以便最大程度地保留日志轨迹中记录的其他行为。与传统噪声日志过滤算法过滤掉包含噪声日志的整条日志轨迹不同,所提算法在移除噪声日志的同时最大程度地保留了原始日志中的其他非噪声日志。     

基于行为特征网的流程模型分解挖掘

为了使包含活动数目较多的事件日志有效挖掘流程模型,提出基于行为特征网的流程模型分解挖掘方法,基于活动日志确定各活动间的行为足迹关系,推得相应的行为矩阵;结合行为矩阵计算行为关系图,从而产生活动聚类;通过现存挖掘算法过滤子日志挖掘子网,并对子网添加接口库所形成子网行为特征网;在行为特征网的基础上,运用合成网的观点合成整网,以此挖掘流程模型。最后通过仿真分析验证了该分解挖掘方法的有效性。     

基于Artifact操作日志的业务流程挖掘

为发现业务流程中的有用知识,结合以数据为中心的业务流程管理与流程挖掘技术,通过记录业务流程中关键数据实体的操作、操作者和操作时间,建立Artifact操作日志。基于Artifact操作日志进行流程挖掘,发现流程中的Artifact生命周期模型,分析流程中Artifact实例之间的依赖关系和执行者之间的社交网络关系,给出违规流程的查找算法。研究结果表明,以数据为中心进行业务流程挖掘能够发现关键业务数据之间的交互关系,为分析流程的正确性提供有效的方法。     

基于Petri网的业务流程低频行为挖掘与优化分析

低频行为的挖掘是业务流程管理的重要内容之一,区分有效低频和噪音在业务流程优化中显得尤为重要。已有挖掘方法多是从数据属性研究低频行为,较少根据不同模块间的行为属性来分析低频行为,由此提出基于Petri网的业务流程低频行为的挖掘与优化方法。首先,通过用流程树切的直接流图表示日志的行为关系,并与初始模型做匹配,发现所有的低频序列;然后,计算日志与模型的行为距离向量,基于行为紧密度区分有效低频日志和噪音日志,优化事件日志;其次,利用不包含噪音序列的事件日志通过融合交互模块网与特征网,挖掘得到一个优化的业务流程模型;最后,通过具体的实例分析和仿真实验验证了该方法的有效性。     

关系数据库中事件日志的紧邻关系高效挖掘方法

关系数据库作为企业管理数据的主要工具,在信息系统运行过程中记录下大量事件日志。传统的流程挖掘技术主要处理用文件存储的XES格式日志数据,每次挖掘任务都需要手工从数据库导出最新日志文件,整个过程操作十分繁琐,且无法充分利用关系数据库强大的数据处理能力。针对该问题,研究了面向关系型日志数据的流程挖掘策略与算法。针对关系数据库中储存的大规模事件日志,利用关系数据库的快速排序能力,提出一种挖掘流程任务之间紧邻关系的近似线性挖掘算法,提高了关系型事件日志的流程挖掘效率。该算法对业务数据库侵入性小,具有较好的通用性。该算法已在开源软件平台ProM上实现,通过基于大规模事件日志的对比实验验证了该方法的高效性。     

一种新的工作流模型挖掘算法

为提高工作流模型挖掘技术的准确性，提出了一种新的工作流模型挖掘方法。首先，阐述了工作流模型直接依赖矩阵的定义，并利用工作流日志建立了直接依赖矩阵的算法，设计了一种基于直接依赖矩阵的模型自动生成算法。给出的模型实例表明了这种方法在提高模型准确率与描述能力等方面的优势所在。     

基于Petri网的分层业务过程挖掘方法

已有的过程挖掘方法通常以事件日志为输入,挖掘得到扁平过程模型,然而这些方法并不能很好地支持任务之间嵌套关系的识别和分层过程模型的挖掘。由此,提出一种从带有任务生命周期信息的事件日志中识别任务之间嵌套关系,进而挖掘分层业务过程模型的方法,挖掘得到的模型用分层Petri网来描述。在分层过程模型的基础上,给出了模型质量度量方法。为了提高所提方法的通用性和对事件日志中的噪声和低频行为的处理,定义了基本任务关系的频次和频率,并引入噪声阈值来过滤低频关系。所提方法均已在开源过程挖掘平台ProM工具中实现。基于仿真日志数据和真实日志数据,定量比较了所提方法与已有过程挖掘方法挖掘模型的质量,进一步验证了本文方法针对分层业务过程模型挖掘的优势。     

基于关系矩阵的工作流日志重复任务识别算法

针对传统工作流模型挖掘算法不考虑模型中重复任务的存在,导致挖掘出的模型精确度不高的问题,提出一种基于关系矩阵的重复任务识别方法。通过分析工作流执行日志得到所有事件的前驱后继关系,根据不同的模型结构进行事件重命名,再基于同类别重复事件之间的相似度对重复事件进行聚类得到最优识别结果。实验表明,该方法能正确有效地识别工作流日志中的重复任务,减少模型中的不可见任务,最终提高工作流模型挖掘方法的精确度和可理解性。     

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.