面向对象Petri网的离散事件系统仿真建模

将Petri网技术和O－O技术结相合,利用消息驱动机制反增强其描述能力而形成对象Petri网（OOPN）,它用面向对象的方法建立系统整体框架,用有色Petri网描述对象,对消息驱动机制对象间传递消息,能较好地将0－O技术和Petri网结合起来,以实现仿真建模。     

基于Petri网整数规划的安全操作路径综合

基于Petri网结构,针对安全生产操作建立整数规划模型,进而实现经济效益与安全生产最优综合。首先,根据Petri网概念,拓扑管酪与阀门模块和故障模块,由此建立安全嗍于声璐径的超级结构,然后,根据Petri网中标记状态的传递情况,确定整数规划模型中的约束条件,最后,考虑权衡最小操作数和最低故障期望建立双目标函数．通过实例验证模型和算法的正确性和有效性,并用GAMS中的CPLEX模型进行Pareto前沿理想点优化求解,得到令人满意的折中安全操作路径。     

莺琼盆地高温高压砂岩气藏储层应力敏感性实验

高温高压气藏储层应力敏感性评价对储层在地层温压条件下的真实物性变化特征的正确认识及开发方案的合理设计都至关重要。本文选取莺琼盆地某气田物性不同的3块岩样,在温度140℃、压力2~70 MPa下进行覆压实验,结合压汞和X射线衍射实验,研究孔隙度、渗透率与净上覆压力之间的变化关系。结果表明,孔隙度、渗透率与净上覆压力之间的关系可通过幂函数形式进行良好的表征,且可分为三个阶段,其对应的孔渗参数变化幅度占比约为36:13:1;岩样的应力敏感程度与其基础孔渗无关,与矿物成分及微观结构相关;硬质组分含量越少,孔隙度应力敏感性越强,硬质组分含量越少、喉道半径越小,对应的渗透率应力敏感性越强;在同等条件下,渗透率应力敏感性明显高于孔隙度应力敏感性,二者相差约4~10倍;与常规评价方法相比,以气藏温压条件下的孔渗参数作为起始点而得到的孔隙度和渗透率应力应敏感性将分别降低65%和38%左右。该文为该地区高温高压砂岩储层应力敏感性研究提供了实验支撑。     

技术要素市场均衡理论探讨

文章根据经济学关于市场均衡的基本原理,在假定技术是一种生产要素的前提下,运用了净现值法和博弈分析法,对技术要素市场进行了探索性研究;探讨了技术要素市场的均衡问题,并论证了技术要素市场的均衡条件。     

Ecosystem valuation and the conservation of wild lands in visorous economic resions： A case study in Jiuduansha Wetland, Shanshai

As the loss of wild lands to satisfy traditional economic development has become a global environmental problem in recent decades, using ecosystem valuation to estimate the total economic value （TEV） of an ecosystem has become popular. The main purpose of the ecosystem valuation is to strengthen the importance of ecosystems, and bring the ecosystem services into the traditional cost-benefit analyses of land use strategy. Some studies have illustrated that in remote areas, wilderness can produce more value if it is conserved, rather than converted to traditional agricultural or industrial uses. The same situation does not seem to exist in vigorous economic regions. Thus, a case study was conducted on the Jiuduansha Wetland in Shanghai using three approaches： the direct market valuation, the replacement valuation and the contingent valuation. The net present TEVs of three land use scenarios over one hundred years were evaluated. The results proved that simply based on ecosystem valuation, when compared with the other two scenarios of ＂conservation＂ and ＂selective use＂, ＂partial conversion into terrene （dry land）＂ of Jiuduansha might be the optimal scenario for the well-being of the people in Shanghai. Land price was identified as the most important factor. This situation is likely due to the scarcity of land available for traditional economic development in Shanghai. Thus, we speculated that the fate of the wilderness to ＂be destroyed＂ in vigorous economic regions could not be changed simply based on ecosystem valuation. However, the variety of interest by local residents in wilderness might enhance the TEVs of scenarios such as ＂conservation＂ and ＂selective use＂, and affect the valuation results. Since some important benefits of natural ecosystems remain unknown and others are underestimated, we suggested that any land use decisions regarding the Jiuduansha Wetland should be conservative and cautious as converting wetlands into terrene is an irreversible process.     

并行测试中死锁避免的设计与仿真

设计了一个双通道运算放大器芯片SD358D的并行测试仿真实例。实例中应用USB数据采集卡和HPVEE软件组成的虚拟仪器对两路放大器的三个指标进行并行测试。由于两个测试任务共享仪器资源,容易发生死锁。为了解决并行测试中的死锁问题,首先为并行测试建立Petri网模型,模型中的变迁发射序列与系统任务调度路径一一对应,利用遗传算法搜索模型中无死锁的序列,然后控制系统按照这些无死锁的路径调度测试任务,就可以有效避免死锁的发生。最后通过实验结果,验证了该方法的正确性。     

Application of Petri Net to Fault Diagnosis in Satellite

1. INTaODUCTIONPetri net is always applied to discrete dynamic systems as a modeling toOl. It has adVantages against Othertools as direct modeling and strict analysis. Petri net can be considered as a graph which is converted intoother from known knowledge represelltation or from st~ure, funcfion or behavior of a system. The occurs when the variables of a system increase that calculation of system design becomes too complicsted to becompleted by hand. Instead, it comes into possible at t…     

一种新的工作流模型及其在产品开发过程中的应用

分析了传统工作流模型的不足之处,在此基础上提出了一种新的工作流模型。文章通过定义活动、参入者、工作流、活动实例、过程实例、发送、工作项、工作项列表八个基本概念建立了这种模型的数学描述,介绍了工作流的运行算法。最后给出了这种模型在产品开发过程中的一个应用实例。     

基于Petri网的航运业务流程的仿真优化

论文利用Petri网理论及相关的仿真软件,对航运业务流程进行了模拟优化分析。通过研究,得出的主要结论是：航运业务流程的优化对提高航运企业的管理效率和水平是十分重要的。在这方面,Petri网理论和相应的仿真软件（ExSpect）提供了一个非常有效的优化分析工具;航运业务流程作为物质流和信息流的紧密结合,其优化管理的关键在于引入信息技术,以提高业务信息传递和处理的效率。     

航空电子综合化网络系统研究

采用Petri网理论建立航空电子综合化网络系统的模型 ,通过模型对航空电子综合化网络系统的结构和动态特性进行了描述、分析和研究。