提高网络环境下的检索效率

围绕查全率、查准率这两个重要指标对网络环境下影响检索效率的因素进行了分析,提出提高网络环境下检索效率的一些方法,以便更好地服务于用户.     

Markov chain Monte Carlo methods for high dimensional inversion in remote sensing

Summary.  We discuss the inversion of the gas profiles (ozone, NO₃, NO₂, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the 'Global ozone monitoring of occultation of stars' instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for a more comprehensive statistical inversion are presented. A direct inversion leads to a non-linear model with hundreds of parameters to be estimated. The problem is solved with an adaptive single-step Markov chain Monte Carlo algorithm. Another approach is to divide the problem into several non-linear smaller dimensional problems, to run parallel adaptive Markov chain Monte Carlo chains for them and to solve the gas profiles in repetitive linear steps. The effect of grid size is discussed, and we present how the prior regularization takes the grid size into account in a way that effectively leads to a grid-independent inversion.     

具体应用中的矛盾分析法之种种

矛盾分析法在科学认识中的具体应用,可作多侧面的展开,形成多方面的更为具体的科学方法。这些具体科学方法可概括为,矛盾的定性分析法、矛盾的定位分析法、矛盾的定点分析法、矛盾的定量分析法、矛盾的定势分析法、矛盾的历史过程分析法、矛盾的逻辑过程分析法、矛盾的系统分析法、矛盾的对立面互补分析法等等.它们均体现哲学方法与具体科学方法的一致性。     

新时期高等学校教师培训工作的思考

分析了高等学校教师培训工作的现状,即不完全适应时代发展的需要;不完全适应我国加入WTO后高等教育与国际接轨的需要;不完全适应高等教育自身深化改革和发展的需要;不完全适应教师参训的个性愿望的需要。针对高等学校教师培训实际工作中存在重学历培训,轻师德培养;对教师创新能力、实践能力的培养不够重视;经费短缺,内容陈旧,考核机制不够完善等问题,提出了健全规章,实行依法培训;加强师德建设,采取多种形式,提高教师综合素质;设立专项培训经费及建立健全教师培训的激励机制的对策。     

论WTO框架下技术性贸易壁垒对我国对外贸易的影响及对策

文章分析了我国入世后,在关税壁垒和许多非关税壁垒对我国外贸发展的影响日渐减弱的情况下,WTO框架下的技术性贸易壁垒对我国外贸的不利影响.并提出四项对策:提高国内对技术性贸易壁垒的认识和了解,使企业重视技术性贸易壁垒的不断变化;将技术性贸易壁垒转化为标准化的推进器,提高产品质量;强化知识产权保护,使企业能不断提高自身的技术水平;实施"走出去"策略,规避繁苛的技术贸易壁垒,以期对我国外贸实践有所助益.     

大学计算机专业“基础原理”课的教学探讨

本文针对现代大学生学习计算机专业“基础原理”课程存在的种种客观问题,通过分析这些问题找出其中原因,并介绍对这些问题所采取的解决方案。教学实践表明,这些方案对学生学习“基础原理课”起到了较好的效果,提高了这类课程的教学质量。     

创新意识和思维方法论

美国著名经济学家熊彼特曾说,经济增长并不是由于资本、劳力等生产要素的增加所引起的植物性增长,而是创新所引起的增长。20世纪以来的100年,不仅在科学技术方面是一个创新的时代,同时也是社会变革最为迅速的时代。科学技术创新是社会发展的促进剂,社会创新同样对社会、经济发展产生深刻的影响。为此必须研究创新和创新思维方法的诸多方面,不断地用智慧去提出问题和解决问题,从而不断地产生新的思维方式和框架。在自由的思考之中,我们才最有可能产生创新。     

Discrete time modelling of disease incidence time series by using Markov chain Monte Carlo methods

Summary.  A stochastic discrete time version of the susceptible–infected–recovered model for infectious diseases is developed. Disease is transmitted within and between communities when infected and susceptible individuals interact. Markov chain Monte Carlo methods are used to make inference about these unobserved populations and the unknown parameters of interest. The algorithm is designed specifically for modelling time series of reported measles cases although it can be adapted for other infectious diseases with permanent immunity. The application to observed measles incidence series motivates extensions to incorporate age structure as well as spatial epidemic coupling between communities.     

Social identities and political cleavages: the role of political context

Summary. Using a novel method, the paper investigates the influence of social group identities on attitudes and on voting in a variety of political contexts. Examining the major regions of Britain, Canada and the USA, we find considerable national and regional diversity in the nature of social cleavages. For example, social class and race had widely different effects across societies, but within societies their effects on attitudes and on voting were very similar. However, despite that, age and religion had a similar effect on attitudes across societies; the effects on voting varied considerably. The significant within-country differences underline the importance of using region, rather than country, as the unit of analysis. More importantly, these results highlight the role of political context, especially competing cleavages and the structure of party competition, in the establishment of politically relevant social cleavages.     

IT教学中教学方法的探讨

教学方法是实现教学目的所采用的途径和手段。信息产业的高速发展要求教育者不断改进教学方法。针对目前 IT教学的情况 ,本文对教学方法从七个方面进行了探讨 :考试的重点、理论课程与实验课程的安排、教材的更新、学生创新能力的培养、教学活动的方法、与学生的交流、教学模式的多样化