基于一阶迁移系统的限界模型检测工具实现

基于布尔可满足性(SAT)的限界模型检测是一种高效的模型检测方法，它具有快速查错，反例最小化等特点，已经成为学术界和工业界关注的热点。近些年出现了很多集成限界模型检测算法的验证工具，如ITC-IRST、卡内基梅隆大学(CMU)等多家科研机构联合开发的NuSMV工具；加利福尼亚大学伯克莱分校(UC Berkeley)、科罗拉多大学博尔德分校(CU Boulder)联合开发的VIS工具等。因此目前对于限界模型检测方法的研究和相关工具的设计与开发具有重要而广泛的意义。在进行限界模型检测的建模过程中，不同的工具采用了自定义的建模语言。如经典工具SPIN采用的建模语言是Promela语言，NuSMV采用的是自定义的NuSMV语言。随着系统验证规模的不断增大，建模语言的特点将会直接影响到建模的效率。例如采用NuSMV语言去建立一个网络通信协议模型会显得比较复杂和耗时，应用NuSMV语言去描述一个简单的数据链路层网络协议ABP协议(Alternating Bit Protocol)就不如采用Promela语言去描述显得直观和自然。 为了简化在限界模型检测过程中模型的建立过程，本文给出了一种采用基于一阶迁移系统语言描述的模型建立方法，并在一阶迁移系统语言中实现了通道的功能，从而增强了描述能力。在此基础上完成了一个以基于插值和k步归纳限界验证算法为核心的模型检测工具(BMCF)。最后利用该工具对常见的互斥协议，简单数据传输协议的性质进行了分析与验证。结果表明，利用该工具对系统进行建模具有方便直观的特点，并借助实现的验证算法能高效的检验安全性质的正确性，如果性质不成立工具会给出反例提示。

事务监控器的Web服务支持

事务监控器是开发、部署、监控和管理分布式事务性应用的基础平台.随着Internet和企业应用集成的发展,许多应用要求能通过广域网访问部署于事务监控器上的服务,同时能与其它分布式系统互操作,但传统的事务监控器作为一种封闭的结构,对此支持不足.Web服务是一种新的分布式组件标准,可方便地部署于广域网上并灵活地进行企业应用集成,本文提出了事务监控器支持Web服务的一个可移植的设计框架TP-WS,可以在符合X/Open DTP模型的事务监控器中支持Web服务.本文设计现已应用到事务监控器ISTX2.0中.

feedback fuzzy-dvs scheduling of control tasks

To consider the energy-aware scheduling problem in computer-controlled systems is necessary to improve the control performance, to use the limited computing resource sufficiently, and to reduce the energy consumption to extend the lifetime of the whole system. In this paper, the scheduling problem of multiple control tasks is discussed based on an adjustable voltage processor. A feedback fuzzy-DVS (dynamic voltage scaling) scheduling architecture is presented by applying technologies of the feedback control and the fuzzy DVS. The simulation results show that, by using the actual utilization as the feedback information to adjust the supply voltage of processor dynamically, the high CPU utilization can be implemented under the precondition of guaranteeing the control performance, whilst the low energy consumption can be achieved as well. The proposed method can be applied to the design in computer-controlled systems based on an adjustable voltage processor.

基于XML的企业信息集成平台实现及应用

随着企业可获取的信息的大量增长,信息的种类和结构也越来越丰富。从传统的关系数据库,到XML文档以及分布于Web上的大量半结构化的信息。如何把各种不同的数据源统一在一个信息集成平台上,使用户能够高效地,透明地操作各类信息,已经成为一个重要的课题。文章提出的基于XML的企业信息集成框架CII,详细讨论了该框架的设计、实现,以及在国家“九五”重点科技攻关项目:石化应用软件典型示范工程及产品开发上的应用。同时针对工业生产企业中实时数据库的大量使用,该文还专门研究了集成实时数据库信息面临的问题,并提出了相应的解决方案。

Kinetic study of hydrolysis of xylan and agricultural wastes with hot liquid water

We investigated the kinetics of hot liquid water (HLW) hydrolysis over a 60-min period using a self-designed setup. The reaction was performed within the range 160-220 °C, under reaction conditions of 4.0 MPa, a 1:20 solid:liquid ratio (g/mL), at 500 rpm stirring speed. Xylan was chosen as a model compound for hemicelluloses, and two kinds of agricultural wastes-rice straw and palm shell-were used as typical feedstocks representative of herbaceous and woody biomasses, respectively. The hydrolysis reactions for the three kinds of materials followed a first-order sequential kinetic model, and the hydrolysis activation energies were 65.58 kJ/mol for xylan, 68.76 kJ/mol for rice straw, and 95.19 kJ/mol for palm shell. The activation energies of sugar degradation were 147.21 kJ/mol for xylan, 47.08 kJ/mol for rice straw and 79.74 kJ/mol for palm shell. These differences may be due to differences in the composition and construction of the three kinds of materials. In order to reduce the decomposition of sugars, the hydrolysis time of biomasses such as rice straw and palm shell should be strictly controlled.