神经网络在智能公交实时调度中的设计与实现

神经网络是一种新兴的数学建模方法,它具有识别复杂非线性系统的特性,比较适合实时调度。在智能公交实时调度中加入误差反向传播算法,利用误差反向传播算法超强的学习能力和泛化能力,通过对海量公交历史调度数据的学习,可以建立公交车到达目的站点的预测模型;通过实时GPS数据,就可以预测车辆到达目的地的大概时间,为建立智能公交调度提供极大方便。     

嵌入式实时数据库系统并发控制协议AC-Based OCC-FV研究

替代和补偿是实时事务的两个基本特点,也是并发控制的主体,同时给并发控制带来了新的问题。AC-Based OCC-FV协议把替代和补偿综合到乐观并发控制协议OCC-FV中来,对于处于接纳队列中的每个事务,尽可能地选择无冲突替代进入就绪队列,但这只是一个理想情况。如果冲突不可避免,不仅要选择一个合适替代参与并发控制,即使冲突发生时,也要确保系统始终处于一个安全状态。在冲突消解时,结合补偿的特点,对乐观并发控制协议OCC-FV进行了扩展,当事务失败后,立即调度相应补偿事务,以防止系统灾难的发生。     

基于Openfire+Spark构建IM实时交流平台

分析即时通讯交流工具在国内外图书馆应用现状,指出目前各种IM工具的不足之处,并提出以开源软件Openfire+Spark构建本地IM实时交流平台的解决方案。介绍Openfire和Spark软件的功能特点,指出技术思路,同时以南京大学图书馆的IM实时交流平台的搭建为例说明实践过程和应用效果。     

国内重点高校图书馆实时咨询服务调查研究

通过网页浏览、问卷调查及实时咨询等方式,从使用软件、服务时间、服务对象、服务效果等方面,对"211工程"高校图书馆实时咨询服务开展现状进行调查和分析,并就正确认识实时咨询、树立"大咨询"概念提供了一些思考和建议.     

植物多样性的分子生物学研究方法

植物多样性是生物多样性的基础，它的保护和可持续利用是维持全球经济健康发展、全球气候稳定的重要因素之一，也是保持我们赖以生存环境的重要内容。对植物多样性的分子生物学研究方法进行了综述，并着重介绍了分子标记的最新进展及其在植物多样性研究中的广泛应用。     

支原体衣原体性小儿肺炎的流行病学研究

对肺炎支原体(MP)、沙眼衣原体(CT)性肺炎进行流行病学的实验研究。采用痰MP、CT荧光定量PCR结合探针的体外DNA扩增和检测。MP-DNA感染阳性率为8.2%,CT-DNA感染阳性率为6.7%,两者混合感染阳性率为0.27%。小于1岁大于3岁年龄组比较MP感染阳性检出率(x2=28.72,P<0.01)和CT感染阳性检出率(x2=5.80,P<0.05)均有显著性差异。MP阳性检出率秋季与春季比较(x2=7.089,P<0.01);CT阳性检出率秋季与春季比较(x2=60.346,P<0.01)及夏季与春季比较(x2=28.1756,P<0.01)均有显著性差异。MP和CT易感年龄较传统的患病年龄有明显提前趋势,感染季节MP以秋季为主,CT以夏秋季为主。     

An integrated DBP for streams with (<Emphasis Type="Italic">m,k</Emphasis>)-firm real-time guarantee

(m,k)-firm real-time or weakly hard real-time (WHRT) guarantee is becoming attractive as it closes the gap between hard and soft (or probabilistic) real-time guarantee, and enables finer granularity of real-time QoS through adjustingm andk. For multiple streams with (m, k)-firm constraint sharing a single server, an, on-line priority assignment policy based on the most recentk-length history of each stream called distance based priority (DBP) has been proposed to assign priority. In case of priority equality among these head-of-queue instances, Earliest Deadline First (EDF) is used. Under the context of WHRT schedule theory, DBP is the most popular, gets much attention and has many applications due to its straightforward priority assignment policy and easy implementation. However, DBP combined with EDF cannot always provide good performance, mainly because the initial, DBP does not underline the rich information on deadline met/missed distribution, specially streams in various failure states which will travel different distances to restore success states. Considering how to effectively restore the success state of each individual stream from a failure state, an integrated DBP utilizing deadline met/missed distribution is proposed in this paper. Simulation results validated the performance improvement of this proposal. Project supported by the National Natural Science Foundation of China (No.60203030) and Advanced Research Program of France-China (Nos. PRA S101-04, PRA S103-02)     

Design and FPGA verification of a novel reliable real-time data transfer system

Considering the increasing use of information technology with established standards, such as TCP/IP and XML in modem industrial automation, we present a high cost performance solution with FPGA （field programmable gate array） implementation of a novel reliable real-time data transfer system based on EPA （Ethemet for plant automation） protocol and IEEE 1588 standard. This combination can provide more predictable and real-time communication between automation equipments and precise synchronization between devices. The designed EPA system has been verified on Xilinx Spartan3 XC3S1500 and it consumed 75% of the total slices. The experimental results show that the novel industrial control system achieves high synchronization precision and provides a 1.59-ps standard deviation between the master device and the slave ones. Such a real-time data transfer system is an excellent candidate for automation equipments which require precise synchronization based on Ethemet at a comparatively low price.     

一种实时入侵检测系统设计与实现

针对IDS存在的漏报和误报率高的缺陷,本文首先在分析了主流操作系统Windows的消息驱动特征后,介绍了如何利用系统调用截获技术,将系统调用截获至判断机构,安全的系统调用继续,非安全系统调用则重定向到检测机构进行实时入侵检测。最后,本文提出了一种实时入侵检测系统的模型并给出了简单的实现方案。