基于DSPN的CAN/LIN网络建模及性能分析

文章针对广泛应用的CAN/LIN网络,阐述CAN和LIN网络通信机制,采用确定与随机Petri网DSPN对其分别建模,并根据协议规范设定参数,对所建模型仿真实验,获得CAN和LIN网络吞吐量、消息平均传输延迟以及有效消息率等性能指标。结果表明,CAN在其能力范围内可保证高优先级消息的实时性和稳定性,LIN的实时性由消息负荷决定,所得性能参数可为实际应用提供理论指导。     

供水管网水质模糊评价的探讨

供水管网水质评价是供水企业了解管网运行状况和用户水质情况的重要途径.针对管网水质评价结果难以量化的问题,提出采用模糊数学评价法对管网水质进行评价.首先建立水质指标因素集和评价集,然后采用专家打分法确定权重集,根据最大隶属度原则确定评价结果,最后以我国南方某市2008年供水管网浊度测试指标为例,进行水质评价计算,结果可靠合理,客观反映了管网水质状况,从而为供水管网运行管理提供了理论依据.     

手机电视技术及应用

介绍了手机电视以及当前手机电视技术标准的分类,总结了手机电视的几种实现方式。     

毕节地区农业科学研究所图书资料室的现状及发展对策

分析了毕节地区农业科学研究所图书资料室的现状和存在的问题,从图书资料室的馆藏文献、网络化、数据库、服务体系及人才队伍建设等方面提出了发展对策。     

浅谈网络环境下图书馆馆藏文献的质量问题

分析了网络环境下图书馆馆藏文献的质量问题,提出了提高馆藏文献质量的方法和对策。     

浅谈地方高校图书馆人才建设的困境与对策

针对地方高等学校图书馆人才建设面临的突出问题,提出了人才建设的对策,以便更好地发挥地方高校图书馆的教学和科研服务职能。     

应用流量控制设备打造高效校园网

本文首先提出了目前在校园网中所面临的带宽饥渴问题,并且对其起因进行了探讨,提出了解决带宽饥渴的首要措施是对校园网进行流量管理的观点：进一步以实例说明了流量控制设备的功能、部署过程、实际效果,提供了一个应对流量问题的思路。     

Performance evaluation of the fixed relay in OFDMA systems

Performance of fixed relays in orthogonal frequency division multiple access (OFDMA) systems, especially the coverage and capacity performance at the cell edge, is evaluated in this paper.Two methods, theoretical analysis and calculation and Monte Carlo simulation, are used for the evaluations.By theoretical analysis and calculation, frequency efficiency equation of a relay is introduced and numerical results are calculated.Monte Carlo simulation results also verify that the calculation method is reasonable.The evaluation shows that a relay can increase system performance to a certain level if it is designed appropriately, otherwise it will be harmful for the system performance, even to reduce it.     

Genetic-fuzzy HEV control strategy based on driving cycle recognition

A genetic-fuzzy HEV control strategy based on driving cycle recognition (DCR) was built. Six driving cycles were selected to represent different traffic conditions e.g. freeway, urban, suburb. A neural algorithm was used for traffic condition recognition based on ten parameters of each driving cycle. The DCR was utilized for optimization of the HEV control parameters using a genetic-fuzzy approach. A fuzzy logic controller (FLC) was designed to be intelligent to manage the engine to work in the vicinity of its optimal condition. The fuzzy membership function parameters were optimized using the genetic algorithm (GA) for each driving cycle. The result is that the DCR_fuzzy controller can reduce the fuel consumption by 1.9%, higher than only CYC_HWFET optimized fuzzy (0.2%) or CYC_WVUSUB optimized fuzzy (0.7%). The DCR_fuzzy method can get the better result than only optimizing one cycle on the complex real traffic conditions.     

一种基于脆弱点依赖图的脆弱性评估方法

为弥补目前网络脆弱性评估系统比较简单、评估结果不全面不准确的不足,提出一种基于脆弱点依赖图的网络脆弱性评估方法,并在该评估方法基础上开发出相应的评估系统.该方法吸收了通用弱点评价体系(CVSS)的优势,同时与目标网络的脆弱点依赖图很好地结合起来,可对网络脆弱性做出一个客观评价.在计算过程中,该方法将脆弱性可利用性和脆弱性影响分开计算,并与实际目标网络中的脆弱点依赖图相结合,从而使得计算值更有参考和实用价值.