Design and implementation methodology based on Petri net formalism of flexible manufacturing systems control

This paper presents an aided design methodology of flexible manufacturing system control with a view to industrial implementation. The approach considered through a modelling phase, the a validation phase by simulation and finally a distributed implementation phase. In the modelling phase, based on the Petri net formalism, we demonstrate the hierarchical aspect which separates the part flow control and the product resource control. In addition, we emphasize generic aspects which allow us to use an object-oriented approach. These aspects and the set of modelled objects are directly used in the simulation and production phases after an automatic translation in an implementation language (ADA in our case). In consequence, the distributed location for those two phases is well facilitated from the viewpoint of the approach used.     

Ranking paired contestants

The ranking of paired contestants (players) after a series of contests is difficult when every player does not play every other player. In the 1975 JASA Mark Thompson presented a maximum likelihood solution based on the assumption that the probability of any one player defeating any other is a function only of the difference in their ranks. Here the linear approximation to that likelihood is shown to lead to a nonparametric measure of the efficacy of the ranking, called the net difference in ranks (NDR) , which is the sum of the differences in ranks of the paired players in the observed contests that agree with the ranking minus the sum of the differences in ranks in the observed contests that disagree with the ranking (upsets) . The subject is part of a large literature that has been consolidated by H.A. David in The Method of Paired Comparisons (1963, 1988). The method was introduced by the psychophysicist Fechner in 1860 and has been widely applied to sensory testing,     

英语网络语言理据刍议

英语网语成因复杂,既受社会因素、心理因素、黑客因素影响,又同人类认知及语言自身发展规律密不可分。深层次探析该语言现象的理据,为研究汉语网语及未来语言的发展趋势提供参考。     

The reality of net capital gains and annual profit on NZ primary producing businesses: data from a recent survey of all farm types

ABSTRACT

Annual net cash returns and net capital gains provide farmers with their actual and potential monetary rewards, respectively. This article reports on a national farm survey showing both actual and potential returns, on average, are not as high as might be imagined. This is supported by the findings of earlier studies and has implications for rural societies and their associated economies. Data on income, expenses and profit is presented as is data on farm value changes over the life of each farm. The information is adjusted for inflation to provide ‘real’ data. The profit and net capital gain figures are divided into groupings based on a range of criteria such as total farm capital, and labour compliment as a reflection of farm size. Statistically significant differences occur for some groupings such as farm type and farm size.     

知识流模型及其在航天企业中的应用

知识管理的理论和实践吸引了众多学者和企业家的关注,但在具体的实施方法上一直没有形成共识。管理的对象是“知识”,对于知识流动的理解、监测乃至控制是顺利实施知识管理项目的基础。已有的研究对知识流的讨论集中于描述概念,或通过统计分析或调查问卷得到对专利、引用等知识流动的描述。把Petri网理论用在对知识流进行刻画中,提出知识流的Petri网模型,能够描述知识分布的拓扑结构、知识存量、一定时期的知识流量和流速,使得管理人员便于监控和管理知识流动,更好地实施知识管理。把基于Petri网的知识流模型应用于航天企业中,通过实证分析说明该知识流模型对知识流动的刻画能力,并通过对现状的分析,为改进知识流动效率,实现知识管理目标提供支持。     

大学英语教学与综合能力培养

本文根据修订后的<大学英语教学大纲>,倡导在教学实践中运用现代外语教学理论,推行以学生为主体以实践为中心的教学模式,打好大学生英语语言基础,提高大学生运用英语语言的综合能力.     

高校大学生上网情况的调查与思考

近年来,"网络化"作为以信息技术为中心的新技术革命的重要特征已影响到社会各个领域,高等院校是中国社会"网络化"的发展前沿。为了了解和掌握大学生上网的基本情况、打好高校思想政治教育工作的主动仗,笔者对湖南地区六所高校中随机抽取的1000名学生的上网情况进行了调查分析,并从网络管理(道德与法律结合)、德育网站(教育与服务、趣味结合)、学生思想(调研与疏导结合)、师资队伍(引进与深造结合)等四个方面对高校如何进一步加强大学生的网络教育提出了建议,力争能提高高校思想政治教育工作的针对性和实效性。     

农业较发达区域农民纯收入的结构构成及其变化趋势——以广东省高州市为例

在高州农民人均纯收入结构中,来自劳务报酬收入比重呈现上升的趋势,并超过农业经营收入。农民人均收入各个组成部分增长存在较大的差异,其根本原因是三次产业劳动生产率的不同。     

住房市场系统模型研究

从宏观层面建立了包含银行、地产商及消费者在内的住房市场系统模型,重点考虑了信贷对住房市场供需双方的金融支持,构建了住房市场系统的定量分析框架,该框架对于银行主导的住房市场具有一般性。通过中国住房市场的实证分析,证实了模型的有效性。     

远程大气监测网络的信号与信道匹配及设计

研究了远程大气自动监测网络的信道、抗干扰和信号和与信道的匹配问题，介绍了该监测网的设计，讨论了远程设备的自动控制，以及远程通讯，可靠性等问题。