WS-BPEL业务流程与访问控制

针对面向服务的体系结构下企业应用安全需求,通过分析WS-BPEL业务流程特点,提出一种面向执行体的访问控制模型。该模型可以动态地进行权限授予与回收,并引入角色和约束机制。在此基础上,将流程活动映射到访问控制模型元素,从而在流程定义和权限管理隔离的情况下,实现WS-BPEL业务流程执行过程中的访问控制策略实施。     

Windows下缓冲区溢出保护机制及绕过技术

综述当前Windows平台下主要的缓冲区溢出保护机制,该保护机制的绕过技术可以提高漏洞分析与利用的成功率及操作系统的安全性。介绍当前主要的缓冲区溢出保护机制的绕过技术的发展现状。针对堆栈溢出及数据执行保护(DEP)机制的突破技术,分别给出突破原理和方法。通过实验验证了DEP突破技术的有效性。     

Log-based transactional workflow mining

A continuous evolution of business process parameters, constraints and needs, hardly foreseeable initially, requires a continuous design from the business process management systems. In this article we are interested in developing a reactive design through process log analysis ensuring process re-engineering and execution reliability. We propose to analyse workflow logs to discover workflow transactional behaviour and to subsequently improve and correct related recovery mechanisms. Our approach starts by collecting workflow logs. Then, we build, by statistical analysis techniques, an intermediate representation specifying elementary dependencies between activities. These dependencies are refined to mine the transactional workflow model. The analysis of the discrepancies between the discovered model and the initially designed model enables us to detect design gaps, concerning particularly the recovery mechanisms. Thus, based on this mining step, we apply a set of rules on the initially designed workflow to improve workflow reliability. The work presented in this paper was partially supported by the EU under the SUPER project (FP6-026850) and by the Lion project supported by Science Foundation Ireland under Grant No. SFI/02/CE1/I131.     

MES下发动机档案信息系统分析与设计

根据企业汽车发动机档案信息管理存在问题及需求,分析设计了基于MES的发动机档案信息管理系统。设计了系统体系结构、主要功能模块和系统网络拓扑结构。分析了主要功能需要的关键技术,包括数据采集技术、质量数据SPC分析技术等。最后将系统应用于企业实际,验证了此系统的有效性和实效性,可实现企业发动机档案管理的整体优化。     

Automated exploration of datapath and unrolling factor during power–performance tradeoff in architectural synthesis using multi-dimensional PSO algorithm

A novel algorithm for automated simultaneous exploration of datapath and Unrolling Factor (UF) during power–performance tradeoff in High Level Synthesis (HLS) using multi-dimensional particle swarm optimization (PSO) (termed as ‘M-PSO’) for control and data flow graphs (CDFGs) is presented. The major contributions of the proposed algorithm are as follows: (a) simultaneous exploration of datapath and loop UF through an integrated multi-dimensional particle encoding process using swarm intelligence; (b) an estimation model for computation of execution delay of a loop unrolled CDFG (based on a resource configuration visited) without requiring to tediously unroll the entire CDFG for the specified loop value in most cases; (c) balancing the tradeoff between power–performance metrics as well as control states and execution delay during loop unrolling; (d) sensitivity analysis of PSO parameter such as swarm size on the impact of exploration time and Quality of Results (QoR) of the proposed design space exploration (DSE) process. This analysis presented would assist the designer in pre-tuning the PSO parameters to an optimum value for achieving efficient exploration results within a quick runtime; (e) analysis of design metrics such as power, execution time and number of control steps of the global best particle found in every iteration with respect to increase/decrease in unrolling factor.The proposed approach when tested on a variety of data flow graphs (DFGs) and CDFGs indicated an average improvement in QoR of >28% and reduction in runtime of >94% compared to recent works.     

钢铁企业制造执行系统研究

基于BPS／MES／PCS3层结构扁平化管理的钢铁企业综合自动化系统(CIMS)是工业自动化领域前沿课题。制造执行系统MES是实现钢铁企业综合自动化系统集成的关键，是提高企业竞争力的重要技术之一。本文在对钢铁企业生产管理特点分析的基础上，提出钢铁企业制造执行系统体系结构，对其各部分的功能进行了阐述，并进一步讨论了制造执行系统的集成功能。     

Modelling Solids In Four Dimensions

MOSS4 is a proposed language extension which allows the creation of systems that model rigid solids in three dimensions and their movement over time, the fourth dimension. MOSS4 allows the creation of completely independent objects that execute in parallel and communicate using message passing. Each object contains a hierarchy of components which are related to each other via common coordinate spaces, and by joints and constraints. The user can create joint types plus the operations defined on them which then apply to the solid the joint is combined with. The system that MOSS4 generates can switch between realtime and stop-frame modes dynamically, and the user can generate synchronisation points to ensure consistency between independently executing objects.     

多机仿真器SimDSM的设计及实现

仿真器是进行计算机体系结构研究的有力工具。本文以多机仿真器ＳｉｍＤＳＭ为实例,讨论了设计仿真器的一般原理和评价仿真器的标准,ＳｉｍＤＳＭ是为了分析研究分布式共享存储系统而设计的。它基于ＣＩＳＣ结构的Ｉｎｔｅｌ的体系结构,由于采用执行驱动和自定义的线程的实现方法,使得仿真可以高效准确进行。实验的结果表明,该仿真器具有较高的实用性和有效性。     

一种基于执行轨迹监测的微服务故障诊断方法

微服务正逐步成为互联网应用所采用的设计架构,如何有效检测故障并定位问题原因是保障微服务性能与可靠性的关键技术之一.然而,当前的方法通常监测系统度量,根据领域知识,人工设定报警规则,难以自动检测故障并细粒度定位问题原因.针对该问题,本文提出一种基于执行轨迹监测的微服务故障诊断方法.首先,利用动态插桩监测服务组件的请求处理流,进而利用调用树对请求处理的执行轨迹进行刻画;然后,针对影响执行轨迹的系统故障,利用树编辑距离来评估请求处理的异常程度,通过分析执行轨迹差异来定位引发故障的方法调用;最后,针对性能异常,采用主成分分析抽取引起系统性能异常波动的关键方法调用.实验结果表明,该方法可以准确刻画请求处理的执行轨迹,以方法为粒度准确定位系统故障以及性能异常的问题原因.     

面向分布式业务执行的BPEL流程解析方法

当前工业界标准的业务流程描述语言BPEL是一种集中式的编制语言,通常业务执行时由集中式引擎控制,易成为系统的性能瓶颈。提出一种BPEL业务流程解析方法,以与服务直接相关的活动为基础,将流程划分出若干基本单元,通过递归算法将其它活动归属到相关单元,产生多个子流程,实现对原有流程的分割,使业务流程可以分布式执行。实现了一个分布式业务执行原型系统,验证了解析方法的有效性。