科创中国

煤炭运输网络优化设计的目标是使煤炭运输网络广义费用最小.研究的广义费用由运输费用、延误费用及其权重构成,通过分析煤炭运输网络流量分配目标,运用基于三角模糊数的模糊层次分析法得到各目标权重,进而确定各目标对总目标的贡献大小.

The intermittent connection(IC)of the field-bus in networked manufacturing systems is a common but hard troubleshooting network problem,which may result in system level failures or safety issues.However,there is no online IC location identification method available to detect and locate the position of the problem.To tackle this problem,a novel model based online fault location identification method for localized IC problem is proposed.First,the error event patterns are identified and classified according to different node sources in each error frame.Then generalized zero inflated Poisson process(GZIP)model for each node is established by using time stamped error event sequence.Finally,the location of the IC fault is determined by testing whether the parameters of the fitted stochastic model is statistically significant or not using the confident intervals of the estimated parameters.To illustrate the proposed method,case studies are conducted on a 3-node controller area network(CAN)test-bed,in which IC induced faults are imposed on a network drop cable using computer controlled on-off switches.The experimental results show the parameters of the GZIP model for the problematic node are statistically significant(larger than 0),and the patterns of the confident intervals of the estimated parameters are directly linked to the problematic node,which agrees with the experimental setup.The proposed online IC location identification method can successfully identify the location of the drop cable on which IC faults occurs on the CAN network.

The existing researches of the evaluation method of ride comfort of vehicle mainly focus on the level of human feelings to vibration. The level of human feelings to vibration is influenced by many factors, however, the ride comfort according to the common principle of probability and statistics and simple binary logic is unable to reflect these uncertainties. The random fuzzy evaluation model from people subjective response to vibration is adopted in the paper, these uncertainties are analyzed from the angle of psychological physics. Discussing the traditional evaluation of ride comfort during vehicle vibration, a fuzzily random evaluation model on the basis of annoyance rate is proposed for the human body's subjective response to vibration, with relevant fuzzy membership function and probability distribution given. A half-car four degrees of freedom suspension vibration model is described, subject to irregular excitations from the road surface, with the aid of software Matlab/Simulink. A new kind of evaluation method for ride comfort of vehicles is proposed in the paper, i.e., the annoyance rate evaluation method. The genetic algorithm and neural network control theory are used to control the system. Simulation results are obtained, such as the comparison of comfort reaction to vibration environments between before and after control, relationship of annoyance rate to vibration frequency and weighted acceleration, based on ISO2631/1(1982), ISO 2631–1(1997) and annoyance rate evaluation method, respectively. Simulated assessment results indicate that the proposed active suspension systems prove to be effective in the vibration isolation of the suspension system, and the subjective response of human being can be promoted from very uncomfortable to a little uncomfortable. Furthermore, the novel evaluation method based on annoyance rate can further estimate quantitatively the number of passengers who feel discomfort due to vibration. A new analysis method of vehicle comfort is presented.

针对文本中冗余的欠缺,造成在文本中隐藏信息量少而难以实现隐密信息的传输,提出了一种基于聊天表情符号的信息伪装新方法,应用于网络聊天中以增加隐蔽性.该方法简单实用、可操作性强,实验证明,该算法具有良好的不可见性和安全性,容量也较为理想,达到信息伪装的目的.

在可持续发展与低碳经济的背景下,绿色物流逐渐成为一个重要的研究领域.其融入了物流管理学、生态经济学、工业生态学、生态伦理学等交叉学科,也得到学术界和业界的广泛关注.以《中国期刊全文数据库》为主要数据来源,借助NoteExpress、CiteSpace以及Pajek等软件,对绿色物流近年来的研究状况进行统计,分析发表论文数量的年度分布情况,从研究领域的知识结构人手,探究我国绿色物流的研究特点以及研究主题等.

以CNKI数据库收录的(2002-2011年)10年高等职业教育方面的研究论文为数据源,利用SPSS、Excel、Uncient、Netdraw等软件.对文献中的高频关键词进行聚类分析、多维尺度分析和中心度分析.结果表明,这一阶段我国高等职业教育研究的热点主要包括人才培养模式、示范性、课程设置、校企合作、工学结合等.教育教学质量、绩效、国际化等将成为高等职业教育未来研究趋势.

Epidemic算法在某些场景中具有很高的传输成功率、很小的传输延迟,但其适应性较差,在另一些场景中性能会显著下降.分析了影响Epidemic算法性能的因素,认为挤出效应是导致算法性能下降的主要原因;提出了Adaptive机制,其使节点可以根据周围节点缓存的状况调整注入网络数据包的数量,主动地抑制挤出效应的发生,进而改善Epidemic算法性能.仿真结果表明,改进后算法的传输成功率显著提高,路由开销大幅度下降.

依据微博信息资源对企业产品信息进行监测,可以使企业更好地了解用户的相关信息.监测的基本步骤为:采集相关用户的描述标签与相关博文,对标签和博文分别进行聚类,从而发现兴趣社区与相关热门话题.其后以某一知名微博系统为平台,以某一品牌为例,进行相应的实证研究,结果表明所提方法具有一定的实践价值.

信息期望是用户依据其经验和知识,在信息获取和利用之前、之中对信息系统功能、信息服务水平和信息产品价值属性等所确立的一种主观预期与主观判断.通过对213名网络用户进行问卷调查,发现网络用户信息期望由信息表达与服务、信息获取过程、信息内容三个维度16个指标所构成.了解与把握网络用户信息期望构成,据此来优化网络信息资源建设、信息服务和网络建设,将有助于提升用户信息体验与满意度.