主应力轴旋转情况下土的各向异性理论研究进展

从理论方面,对国内外主应力轴旋转情况下土的各向异性研究进行了对比和总结,并提出了一些研究建议。指出在理论方面,应当对屈服面方程采用应力分量表示的模型在三维空间里进行屈服面性状的描述,同时考虑不同加载方向下屈服面的变化特性以及旋转硬化的问题,并应开展对加载方向变化时土体屈服面变化特性的实验研究及理论验证。     

Is students’ energy literacy related to their university’s position in a sustainability ranking?

Abstract

University rankings are increasingly important internationally, and in the UK include a sustainability ‘Green League’. However, there is little evidence about experiences of studying in ‘sustainable universities’. We report an empirical study at five universities in varied positions in the Green League, exploring students’ energy literacy, environmental attitudes and perceptions of their institution’s energy-saving efforts. Although the link to energy literacy is not clear, findings suggest that there are significant differences between students’ environmental attitudes at universities placed at different points in the league. In addition, students at higher ranked universities are more positive about their university’s energy-saving efforts, suggesting that these institutions may exhibit more overt manifestations of sustainability. This is important since students report being more likely to choose energy-conservation behaviours if there is visible representation of energy use. The study is the first to attempt a comparison between universities at different positions in a sustainability ranking.     

Software review

STATISTICA 5.0. StatSoft, 2325 East 13th Street, Tulsa, OK 74104, (918) 583–4149. $995 retail, academic site license—$2,000 for 10 copies. Requirements: 386 or better, 4 Meg RAM, Microsoft Windows 3.1 or 95.     

Fitting Nonlinear Latent Growth Curve Models With Individually Varying Time Points

Individual growth trajectories of psychological phenomena are often theorized to be nonlinear. Additionally, individuals’ measurement schedules might be unique. In a structural equation framework, latent growth curve model (LGM) applications typically have either (a) modeled nonlinearity assuming some degree of balance in measurement schedules, or (b) accommodated truly individually varying time points, assuming linear growth. This article describes how to fit 4 popular nonlinear LGMs (polynomial, shape-factor, piecewise, and structured latent curve) with truly individually varying time points, via a definition variable approach. The extension is straightforward for certain nonlinear LGMs (e.g., polynomial and structured latent curve) but in the case of shape-factor LGMs requires a reexpression of the model, and in the case of piecewise LGMs requires introduction of a general framework for imparting piecewise structure, along with tools for its automation. All 4 nonlinear LGMs with individually varying time scores are demonstrated using an empirical example on infant weight, and software syntax is provided. The discussion highlights some advantages of modeling nonlinear growth within structural equation versus multilevel frameworks, when time scores individually vary.     

Activity theory: A framework for design and reporting on research projects based on ICT

We propose using activity theory as a basis for designing and reporting on research projects that focus on information and communication technology (ICT) as a means to support educational processes. Adopting the theory, we describe teaching/learning activities mediated by ICT using a three level analysis: epistemological, methodological, social assistance. The analysis has been applied to the design and reporting of projects in both mathematics education at primary school level and training in technical innovation in commercial enterprises.     

国外公司治理结构的模式和发展趋势

通过研究国外公司治理结构的模式的特点、利弊，分析国外公司治理结构的发展趋势，结合中国中小民营企业的特点，提出了建立中国中小民营企业治理结构的思路。     

基于马尔柯夫模型的涨渡湖流域土地利用变化预测

基于TM卫星遥感数据,在GIS 技术支持下,建立了涨渡湖流域土地利用数据库;通过提取湿地信息,运用马尔柯夫链模型对该流域土地利用特别是湿地资源在2010年～2015年的数量变化进行预测;运用GIS软件制作了2015年主要变化类型土地的密度分布图,并从人文因素方面阐述了变化的原因。研究表明：涨渡湖流域到2015年湿地的变化趋势是坑塘较目前增加1 713.4hm²,主要围绕涨渡湖流域分布,水田减少2 083.1hm²,主要分布在涨渡湖流域上部;耕地减少277.8hm²,主要在涨渡湖流域的东部以及南部;建设用地增加544.3hm²,主要分布在涨渡湖的北部。总的趋势是除水库坑塘、滩地、沼泽呈现增加趋势,其余河渠、湖泊和水田均呈现减少态势。非湿地变化趋势是草地、建设用地增加,耕地和林地减少。流域土地利用变化的主要因素是围湖造田和城市化等。     

生态学视角下基于熵权可拓模型的山西省人才聚集预警研究

基于生态学的理论视角,结合熵权和物元可拓模型的相关理论,以山西省为例,从生态学的角度构建人才聚集预警的指标体系,建立人才聚集预警熵权可拓模型对山西省2006—2013年的人才预警状况进行实证分析,结果表明:山西省人才聚集处于中度预警状态,制度生态因子、社会生态因子、经济生态因子的推动作用促进山西省人才聚集预警度呈现转好的局面,文化生态因子和教育生态因子阻碍了人才聚集的平衡性发展,出现了向低等级转移的趋势。为防止山西人才聚集的非经济现象更加突出提供理论依据,为山西省人才聚集的良性发展提供参考性意见。     

对我国中小学体育教学模式的理论思考

着重对我国中小学体育教学模式进行理论探讨。提出了多视角、多样化、全方位的体育教学模式新格局,认为提高我国中小学体育教学整体水平的关键在于更新教育观念,建立一定的学说,确定“发展”的体育教学模式。     

From Retrieval Status Values to Probabilities of Relevance for Advanced IR Applications

Information Retrieval systems typically sort the result with respect to document retrieval status values (RSV). According to the Probability Ranking Principle, this ranking ensures optimum retrieval quality if the RSVs are monotonously increasing with the probabilities of relevance (as e.g. for probabilistic IR models). However, advanced applications like filtering or distributed retrieval require estimates of the actual probability of relevance. The relationship between the RSV of a document and its probability of relevance can be described by a normalisation function which maps the retrieval status value onto the probability of relevance (mapping functions). In this paper, we explore the use of linear and logistic mapping functions for different retrieval methods. In a series of upper-bound experiments, we compare the approximation quality of the different mapping functions. We also investigate the effect on the resulting retrieval quality in distributed retrieval (only merging, without resource selection). These experiments show that good estimates of the actual probability of relevance can be achieved, and that the logistic model outperforms the linear one. Retrieval quality for distributed retrieval is only slightly improved by using the logistic function.