Stochastic modelling and analysis of mobility models for intelligent software defined internet of vehicles

Data traffic forwarding and network optimization is essential to effective congestion management in software-defined vehicular networks, and it is necessary for software-defined vehicle networks (SDVN). SDVN is needed to optimize connection performance and network controls in dense and sparse networks to govern data flow between nodes as effectively as possible. Intelligent software-defined internet of vehicles (iSDIoVs) has recently emerged as a potential technology for future vehicular networks. It manages the vehicular ad hoc networks systematically. The link connection of moving vehicles from the central SDN controller may fail. It impacts the efficiency and communication performance because of the lack of connection between vehicles and infrastructure (V2I). The researchers have analyzed the network performance and mobility models in a dense and sparse network to maximize network performance by iSDIoVs. By integrating heterogeneous systems such as IEEE 802.11p and cellular networks into vehicular ad-hoc networks, it is possible to reduce buffer occupancy in iSDIoV and control the mobility and delay bound analysis in V2V communication. The SDN will provide flexibility and reliability to the vehicular networks. An SDN controller manages the data flow in the vehicular network and controls the flow matching rules in the control plane. The iSDIoV and queuing models improve the response time and resource utilization and enhance the network complexity analysis for traffic management services.     

Extending Petri net to reduce control strategies of railway interlocking system

In our previous articles we gave step by step refinement process towards the development of safety properties of moving block interlocking system (MBRIS). The refinement process started from abstraction to fuzzy based safety properties using Z and then fuzzy multi agent specification language. However, one dimensional control of train passing through a switch and level crossing were not discussed. This paper reduces the existing two dimensional controls along the switch and level crossing to one dimensional for shifting it to a train only. For example, in the existing model the train movement along components switches and level crossings depends on both the train and components control. Whereas, in one dimensional control train is the only authority to control a switch and level crossing required for its desired operation. For this reduction, concurrent and mobile agent concepts are required. Therefore, we integrate mobile agent concepts with Petri nets to develop the mobile Petri net (MPN) a new class of PNs. This supports both mobility and concurrency. Further, we prove that the collection of different MPNs in a connected network is a PN. This proof allowed us to use the properties of PN to verify the system. Finally, we use MPN to model the safety properties of MBRIS along the switch and level crossing. This provides one dimensional control to a train along a switch and level crossing which increases the safety of the railway interlocking system. Moreover, we use reachability graph (RG) to verify the switch and level crossing models.     

基于活性顺序图的形式化验证方法及工具研究

近年来,形式化验证方法在软件开发过程的作用越来越大。如何充分利用形式化验证方法提高软件系统的可靠性已成为软件开发者及使用者主要关注的问题。总结了近年来基于活性顺序图的形式化验证方法的研究进展,首先介绍活性顺序图的语言及其表达能力与复杂性,然后深入分析现有的基于活性顺序图的形式化验证的关键技术及其典型应用,最后实现一种基于活性顺序图的运行时验证工具,实验证明使用本验证工具进行形式化验证的可行性。     

软件实现模糊评判法对特高含水期油田开发效果评价

针对目前油藏特高含水期水驱开发效果多项评价指标相互独立、关联性差的特点,编制软件实现各项评价指标及分级标准临界值的动态输入,后台利用模糊评判法将油藏开发状况因素中的一些定性描述定量化,最终以数值的形式判断开发效果并呈现在人机交互界面.将以杏一~三区西部乙块地质特征和油田开发实际数据资料为基础验证软件运行结果,评价符合开发实际.使用此软件评价方便简单,结果全面可靠,同时由于数据录入的动态性,可应用于同类型的其他油藏.     

Diamond软件在晶体对称性教学中的应用-32点群晶体模型库的建立

介绍了用Diamond软件构造32点群晶体结构模型的方法,给出了建立晶体结构模型的具体参数.利用此模型有助于加深学生对点群及其与晶体结构关系的理解.     

ICPS-1000Ⅱ型等离子光谱仪控制系统的升级更新

通过对岛津ICPS-1000Ⅱ型等离子体光谱仪控制系统的升级更新,使用PC系列微机,插入IEEE-488并行通讯接口卡,替代原三菱MULT 116计算机,实现了对ICPS-1000Ⅱ光谱仪主机的控制,将原软件移植成功。进一步开发了该仪器的功能,使其维修、维护和应用变得方便、快捷。     

机电耦联系统余维3动态分岔研究

以r_{sl}, r_{f}以及x_{c}为分岔参数,对具有串补电容的单 机无穷大电力系统的失稳振荡问题,运用动态分岔理论进行了研究. 对系统同时出现有3对 纯虚根特征值的一类多参数高余维分岔情况,运用中心流行方法降维后得到约化方程,对此 强非线性约化方程的求解难点,运用多参数稳定性理论、谐波平衡法、归一化技术和Normal Form方法,得到了系统的解析解. 由分析得知,系统会出现3种Hopf分岔情况、二维环面 情况,以及三维环面分岔解,甚至会出现四维环面,或者更高维的环面分岔. 详细讨论 了系统各种分岔解的稳定性条件和稳定区域,并作了详细的数值分析加以验证.