Dwelling time probability density distribution of instances in a workflow model

This paper presents a method to judge whether a business process is successful or not. A business process is deemed successful if a large enough proportion of instances dwell in a workflow (wait and be executed) for less than given period. By analyzing instances’ dwelling time distribution in a workflow, the proportion of instances which dwell in the workflow for less than any given period will be achieved. The performance analysis of workflow model plays an important role in the research of workflow techniques and efficient implementation of workflow management. It includes the analysis of instances’ dwelling time distribution in a workflow process. Multidimensional workflow net (MWF-net) includes multiple timing workflow nets (TWF-nets) and the organization and resource information. The processes of transaction instances form a queuing model in which the transaction instances act as customers and the resources act as servers. The key contribution of this paper is twofold. First, this paper presents a theoretical method to calculate the instances’ dwelling time probability density in a workflow where the activities are structured and predictable. Second, by this method the analysis of instances’ dwelling time distribution and satisfactory degree based on dwelling time can be achieved. The service time of an instance is specified by the firing delay of the corresponding transition (executing time of the corresponding activity). It is assumed that the service request (processing of a transaction instance) arrives with exponentially distributed inter-arrival times and the firing delay of a transition (executing time of the corresponding activity) follows exponential distribution. Then, the instances’ dwelling time probability density analysis in each activity and each control structure of a workflow model is performed. According to the above results a method is proposed for computing the instances’ dwelling time probability density in a workflow model. Finally an example is used to show that the proposed method can be effectively utilized in practice.     

时间Petri网等效变换的工作流评价

时间性能分析是工作流模型分析和评价的重要方面.首先介绍了业务过程的一般Petri网模型,然后引入时间Petri网建立工作流网的时间约束模型.提出了保持网时间约束特性不变的网变换规则和时间性能计算方法,对工作流网进行化简及时间性能计算,并给出了相应的算法.最后通过一个实例说明本方法的应用过程.     

基于Petri网的电子政务工作流模型研究

设计了一种基于Petri网扩展的、用于复杂工作流模型设计的建模方法及其相关规则。并且通过电子政务系统的网上审批子系统为例,详细阐述了用此方法及其相关规则构建Petri网工作流模型的过程。最后通过Petri网理论对模型进行了正确合理性分析,并对网上审批子系统的资源分配情况进行了定量分析。此建模方法简化了Petri网的建模过程,并保证了正确性和合理性资源分配的分析结果对合理的进行资源分配有指导作用。     

基于GERT网络的工作流动态调整引擎的设计与实现

为了解决工作流业务执行过程中的随机性,提出了基于GERT网络的工作流动态调整引擎的设计方法。介绍了海基数据管理系统和信号流图,探讨了GERT网络解析算法原理,针对发文处理流程,通过海基数据管理系统有效地跟踪发文流程的执行,建立了GERT网络模型进行了求解得到流程执行过程中耗时的范围,最后根据结果由系统管理员设置干预时间来实时的监控和管理工作流。按照实际运行时流程状态重新设计或修改流程定义,实验结果表明了该设计可以有效提高了业务流程的柔性、动态扩展和自动化程度。     

A clustering method based on multidimensional texture analysis

Considering the analogy between image segmentation and cluster analysis, the aim of this paper is to adapt statistical texture measures to describe the spatial distribution of multidimensional observations. The main idea is to consider the cluster cores as domains characterized by their specific textures in the data space. The distribution of the data points is first described as a multidimensional histogram defined on a multidimensional regular array of sampling points. In order to evaluate locally a multidimensional texture, a co-occurrence matrix is introduced, which characterizes the local distribution of the data points in the multidimensional data space. Several local texture features can be computed from this co-occurrence matrix, which accumulates spatial and statistical information on the data distribution in the neighborhoods of the sampling points. Texture features are selected according to their ability to discriminate different distributions of data points. The sampling points where the local underlying texture is evaluated are categorized into different texture classes. The points assigned to these classes tend to form connected components in the data space, which are considered as the cores of the clusters.     

一种基于改进Petri网的工作流案件分布式处理系统模型

针对现有的案件处理系统功能单一、效率低、缺乏并行处理和协调优化能力,无法满足现代案件处理需求的问题,基于改进Petri网的工作流技术,解析案件处理特征,对案件处理系统动态过程进行规划、调度和调整,在建模过程中引入Petri网分布式处理框架和工作流的路由结构、触发机制,建立了一种改进Petri的网工作流案件分布式处理系统模型,并对模型进行定义化描述和合理性验证,为司法部门案件处理提供高效、安全、可靠的平台。     

基于彩色Petri网的工作流权限管理的建模与分析

在一个组织中,权限管理是个非常复杂而又重要的任务。为确保组织的业务过程中各项任务只能被合法的用户所执行,建立授权模型并验证权限分配的正确性是十分必要的。彩色Petri网具有比Petri网更强的表达能力,可以用来建立一个完整的权限管理模型,不仅包含权限管理,还包含安全约束如SoD（职责分离）以及角色层次关系结构（role hierarchy）等概念。使用Petri网建模的一个优势是它建立在坚实的数学基础之上,并且得到了许多分析验证技术和工具的支持,如使用线性代数技术分析授权状态的可达性。     

A global localization approach based on Line-segment Relation Matching technique

This paper presents a novel global localization approach for mobile robots by exploring line-segment features in any structured environment. The main contribution of this paper is an effective data association approach, the Line-segment Relation Matching (LRM) technique, which is based on a generation and exploration of an Interpretation Tree (IT). A new representation of geometric patterns of line-segments is proposed for the first time, which is called as Relation Table. It contains relative geometric positions of every line-segment respect to the others (or itself) in a coordinate-frame independent sense. Based on that, a Relation-Table-constraint is applied to minimize the searching space of IT therefore greatly reducing the processing time of LRM. The Least Square algorithm is further applied to estimate the robot pose using matched line-segment pairs. Then a global localization system can be realized based on our LRM technique integrated with a hypothesis tracking framework which is able to handle pose ambiguity. Sufficient simulations were specially designed and carried out indicating both pluses and minuses of our system compared with former methods. We also presented the practical experiments illustrating that our approach has a high robustness against uncertainties from sensor occlusions and extraneous observation in a highly dynamic environment. Additionally our system was demonstrated to easily deal with initialization and have the ability of quick recovery from a localization failure.     

A virtual metrology model based on recursive canonical variate analysis with applications to sputtering process

In data driven process monitoring, soft-sensor, or virtual metrology (VM) model is often employed to predict product's quality variables using sensor variables of the manufacturing process. Partial least squares (PLS) are commonly used to achieve this purpose. However, PLS seeks the direction of maximum co-variation between process variables and quality variables. Hence, a PLS model may include the directions representing variations in the process sensor variables that are irrelevant to predicting quality variables. In this case, when direction of sensor variables’ variations most influential to quality variables is nearly orthogonal to direction of largest process variations, a PLS model will lack generalization capability. In contrast to PLS, canonical variate analysis (CVA) identifies a set of basis vector pairs which would maximize the correlation between input and output. Thus, it may uncover complex relationships that reflect the structure between quality variables and process sensor variables. In this work, an adaptive VM based on recursive CVA (RCVA) is proposed. Case study on a numerical example demonstrates the capability of CVA-based VM model compared to PLS-based VM model. Superiority of the proposed model is also presented when it applied to an industrial sputtering process.     

基于HLA的实时仿真方法的研究与测试

实时性是某些仿真系统的重要性能指标.分析了运行支撑环境(RTI)消息基本流程及高层体系结构(HLA)时间管理服务对仿真实时性的影响,提出采用多步推进+墙钟控制的时间推进方式来实现实时仿真,并设计了一种测试RTI实时性的试验方案,以及用该试验测试了MAKRTI2.3.3在两种传输服务下的实时性,仿真结果表明,在高速局域网下,采用多步推进的时间推进方式能有效提高仿真实时性,基本上达到大多数半实物仿真系统的实时要求.     

Automatic moment segmentation and peak detection analysis of heart sound pattern via short-time modified Hilbert transform

This paper proposes a novel automatic method for the moment segmentation and peak detection analysis of heart sound (HS) pattern, with special attention to the characteristics of the envelopes of HS and considering the properties of the Hilbert transform (HT). The moment segmentation and peak location are accomplished in two steps. First, by applying the Viola integral waveform method in the time domain, the envelope (E_T) of the HS signal is obtained with an emphasis on the first heart sound (S1) and the second heart sound (S2). Then, based on the characteristics of the E_T and the properties of the HT of the convex and concave functions, a novel method, the short-time modified Hilbert transform (STMHT), is proposed to automatically locate the moment segmentation and peak points for the HS by the zero crossing points of the STMHT. A fast algorithm for calculating the STMHT of E_T can be expressed by multiplying the E_T by an equivalent window (W_E). According to the range of heart beats and based on the numerical experiments and the important parameters of the STMHT, a moving window width of N = 1 s is validated for locating the moment segmentation and peak points for HS. The proposed moment segmentation and peak location procedure method is validated by sounds from Michigan HS database and sounds from clinical heart diseases, such as a ventricular septal defect (VSD), an aortic septal defect (ASD), Tetralogy of Fallot (TOF), rheumatic heart disease (RHD), and so on. As a result, for the sounds where S2 can be separated from S1, the average accuracies achieved for the peak of S1 (AP₁), the peak of S2 (AP₂), the moment segmentation points from S1 to S2 (AT₁₂) and the cardiac cycle (ACC) are 98.53%, 98.31% and 98.36% and 97.37%, respectively. For the sounds where S1 cannot be separated from S2, the average accuracies achieved for the peak of S1 and S2 (AP₁₂) and the cardiac cycle ACC are 100% and 96.69%.     

Constraint-based performance comparison of multi-dimensional interconnection networks with deterministic and adaptive routing strategies

Several studies have examined the relative performance merits of the torus and hypercube taking into account the channel bandwidth constraints imposed by implementation technology. While the torus has been shown to outperform the hypercube under the constant wiring density constraint, the opposite conclusion has been reached when the constant pin-out constraint is considered. However, all these studies have assumed deterministic routing and have not taken into account the internal hardware cost of routers. This paper re-examines the performance merits of the torus and hypercube using both fully-adaptive and deterministic routing strategies. Moreover, it uses a new cost model which takes into account the internal hardware cost of routers.     

基于MCMC方法的非平稳随机信号分析的探索

在对MCMC方法和随机信号参数模型概念学习的基础上,对非平稳随机信号的时变参数模型的构建进行了探索。通过实例,说明构建时变参数模型的关键技术在于产生稳定的概率密度函数。     

Admission control mechanism and performance analysis based on stochastic automata networks formalism

IEEE 802.16 has been designed to support QoS (Quality of Service) in Wireless broadband Metropolitan Networks (WMAN), and specifically in the access networks. To achieve this, the IEEE 802.16.e amendment introduces the service differentiation by five service classes (UGS, ertPS, rtPS, nrtPS and BE). To maintain the QoS of active connections and to avoid any congestion in the network, an Admission Control (AC) is defined. AC aims to accept or reject a new connection according to the negotiated parameters and the availability of resources in the network. This mechanism is not standardized and let to the operators. We tackle this point, by proposing in this study a new Admission Control (AC) that improves the QoS of BE traffic by avoiding a strict bandwidth assignment of other traffics (rtPS and nrtPS) as is defined in major previous studies. The proposed mechanism is based on token bucket for rtPS, nrtPS and BE traffics in order to reduce lightly the number of accepted connections and to improve considerably the number of accepted BE connections. To evaluate the performance of the proposed scheme, we use PEPS (Performance Evaluation of Parallel Systems) which is a powerful tool based on models which can be described with Stochastic Automata Networks (SAN). PEPS can solve complex models with a large state space and with many synchronized events. Therefore, we show that this tool is suitable for wireless network, and specifically for the proposed scheme, toward numerical results we show as we expected that our proposed AC outperform the classical one by reducing lightly the performance of other service classes.     

基于分解的连续Petri网性质分析方法

讨论了最大速度恒定连续Petri网（CCPN）的分解方法以及如何通过子网分析得到原网的性质。首先给出基于库所归属的分解方法,实现了CCPN的分解。为了保证通过子网分析原网的正确性,对合成网的动态不变性进行了证明,并证明了CCPN子网结构性质与原CCPN网性质的对应关系。最后以实例验证了通过子网分析原网的正确性。     

基于Petri网理论的计算机网络性能分析和电子商务模型设计

本文采用Petri网作为建模求解工具,揭示TCP网络的实质,探讨TCP网络的性能分析问题和电子商务系统中的买方和卖方模型设计问题。最后对全文进行了概括性总结,并指出了理论和应用上有待进一步研究的问题。     

基于蒙特卡罗方法的非平稳随机信号分析的探索

在对蒙特卡罗方法和随机信号参数模型概念学习的基础上,对非平稳随机信号的时变参数模型的构建进行了探索。通过圆剧率计算的实例,说明构建时变参数模型的关键技术在于产生稳定的概率密度函数。     

基于有色Petri网的SPIN协议建模与分析

在无线传感器网络路由协议的研究中,对现有协议的分析和验证具有重要意义.形式化建模是分析验证网络协议的一种有效方法.使用形式化工具有色Petri网对无线传感器网络中的SPIN路由协议进行形式化描述,并使用CPN Tools分析和验证了该协议的活性、可达性、有界性等特性.     

H∞ control of dead-time systems based on a transformation

This paper presents a transformation that makes all the robust control problems of dead-time systems able to be solved similarly as in the finite-dimensional situations. With trade-off of the performance, some advantages obtained are: (i) the controller has a quite simple and transparent structure; (ii) there are no any additional hidden modes in the Smith predictor and, hence, there is no additional hidden possibility to destabilize the system; (iii) it can be applied to systems with long dead-time without any difficulty. Hence, the practical significance is obvious.     

Service based communication for MPSoC platform-SegBus

MPSoC platforms offer solutions to deal with communication limitations for multiple cores on single chip, but many new issues arise within the context. The SegBus platform is one of the solutions for application deployment on multi-core applications. There are many applications where identical data is transferred from the same source towards different destinations. Multicast services may come as a performance improving factor for the interconnection platform, together with interrupt service.In this paper, the task is to analyze, how different services can be designed for the SegBus platform and observe the improvement in system performance. The designer can select the services according to the requirements. The running example is represented by the H.264 encoder. The SegBus platform architecture, the communication mechanism, the allocation of processing elements on the platform, the communication services and their implementation are the main topics elaborated here.