煤矿瓦斯和煤尘的监测与控制数学建模建立研究

针对2006年全国大学生数学建模竞赛题“煤矿瓦斯和煤尘的监测与控制”中的三个问题,分别建立了三个模型：第一,模型一判别出煤矿是高瓦斯矿井。第二,模型二通过曲线拟合方法,建立了概率模型,求出了煤矿不安全程度。第三,建立了目标规划模型及其改进模型,求出了矿井在最大安全度下所需的最佳总通风量。     

Alternatives to rules for knowledge-based modelling

The technology of knowledge-based systems undoubtedly offers potential for educational modelling, yet its practical impact on today's school classrooms is very limited. To an extent this is because the tools presently used in schools are mostly rule-based expert system shells, which lack usability. We developed three alternative tools, using ideas from knowledge acquisition research, and compared their effectiveness to that of an established rule-based shell. Children working with the new tools produced higher quality models and developed more positive attitudes. We relate these findings to the forms of representation provided by the new tools and present evidence that modelling increases children's representational skill. We conclude that knowledge acquisition systems and alternative forms of representation can contribute to improved forms of knowledge-based modelling.     

The 'new' politics of education in Britain's changing times

The British Labour Party has continued to make progress on education, following two broad policy paths and adopting a pragmatic approach that does not attempt to force these to cross or converge. One path is that of the quasi market inherited from the previous Conservative administration; the other is characterised as 'intervention' to support those for whom the market remains almost entirely irrelevant. Some observers regard this dual approach as 'opportunism' and Labour's education policy as a 'betrayal' of principle, by which is meant the principle of 'equal opportunity'. Of course, that principle provides equal opportunity to fail as much as to succeed. Rather than leaving education to the market, Labour has focused on the needs of those most likely to be failed by the principle of 'equal' opportunity in a quasi market.     

软土地面中机械化双叠隧道的三维数值模拟

研究目的：通过三维数值模拟,研究隧道施工过程对双叠隧道的影响。创新要点：使用全三维数值模拟方法研究软土中双叠隧道施工对先挖隧道或地面的影响。研究方法：1.运用FLAC软件创建双叠隧道的三维数值模型（图1）;2.分情况模拟机械化双叠隧道的挖掘过程;3.研究不同情况下的地面沉降,水平地面位移,以及隧道衬砌的法向位移、法向力、纵向力和弯曲力矩等。重要结论：1.新隧道施工对现有的隧道有很大的影响,最大影响出现在先挖上层隧道的情况下;2.一般来说,上层隧道的挖掘会比下层隧道产生更大的地面沉降;3.下层隧道产生的法向力总是比上层隧道大;4.在多数情况下,下层隧道产生的法向位移和弯曲力矩要比上层隧道小。     

抽象绘画造型语言的探索与思考

抽象绘画作为一种独立的绘画形式,在造型艺术领域占有着越来越重要的位置.它有着具象绘画无法取代的语言特征,而且一直作为新潮美术的先锋影响着各国的画坛.抽象绘画不仅有其产生、发展的必然性规律和特征,而且有其多方面的艺术价值.我国的抽象绘画应该怎样发展,怎样借鉴西方的经验,走自己的路,应先对抽象绘画的造型语言特征进行探索和研究.     

Assessing students’ understanding of models of biological processes: a revised framework

Models are very important tools when learning and communicating about science. Models used in secondary school biology education range from concrete scale models, such as a model of a skeleton, to abstract concept-process models, such as a visualisation of meiosis. Understanding these concept-process models requires a profound understanding of the concept of models and how they are used in biology. This study evaluates an existing framework for its use in assessing students’ understanding of biological concept-process models. Four additions were required to extend the applicability of the framework to concept-process models. We were also able to give an indication of students’ current level of understanding of these models, showing room for improvement in all aspects of understanding. Since concept-process models have a central place in many scientific disciplines, it is important that students have a deep understanding of the nature, application and limitations of these models. The current study contributes to assessing the way students reason with concept-process models. Knowing how to improve students’ view on the use of concept-process models in biology may lead to higher scientific literacy.     

System competence modelling: Theoretical foundation and empirical validation of a model involving natural,social and human‐environment systems

Constituting a metacognitive strategy, system competence or systems thinking can only assume its assigned key function as a basic concept for the school subject of geography in Germany after a theoretical and empirical foundation has been established. A measurement instrument is required which is suitable both for supporting students and for the evaluation of methodical‐didactic measures. Such a tool is theoretically anchored in an empirically validated geography‐didactic and cognition‐psychological competence model, providing a differentiated representation of both the internal structure of a competency and the proficiency levels. The starting point of this foundation was the development of a normative‐theoretically derived model of geographic system competence. Its empirical validation was performed in different phases aimed at operationalising the competence model by means of test problems. In order to analyse the factor structure of the theoretical model, various item response models were estimated. The item levels of difficulty expected in the competence model were related to the empirical levels of difficulty and predicted by means of ordinary least squares regression to verify the model for proficiency levels. The two‐dimensional competence model – with the two dimensions ‘system organisation and behaviour’ and ‘system‐adequate intention to act’ – exhibits a better fit in reference to the model fit criteria than the one‐dimensional and three‐dimensional models. The correlations between the expected and empirical item difficulties are positive. Items that should be more difficult according to the competence model are actually shown to be more difficult. These findings suggest the reliability and validity of this new measurement instrument for diagnosing and promoting geographical system competence. It has to be implemented in practice as the next step.     

Cross-National Validation of the What is Happening in this Class? (WIHIC) Questionnaire using Confirmatory Factor Analysis

Learning Environments Research - The What Is Happening In this Class? (WIHIC) questionnaire was validated cross-nationally using a sample of 3980 high school students from Australia, the UK and...     

基于行为-内容融合模型的用户画像研究

[目的/意义]为识别并去除非理性投资者的网络评论,提升评论的专业程度与质量,促进理性投资,本文以识别股吧中的用户是否属于噪声投资者为研究任务,进行用户画像。[方法/过程]对股吧的用户发文内容进行深度用户表示学习（deep user representation learning）,结合股吧用户的粉丝数量、影响力、关注量、自选股、吧龄、发帖量、评论量、访问量等行为特征,提出一种行为-内容融合模型（behaviour and content combined model,BCCM）,并在标注数据集上进行实证与对比研究。[结果/结论]实验结果显示,该模型对噪声投资者识别的F1值为79.47%,优于决策树方法（69.90%）、SVM方法（75.61%）、KNN方法（73.21%）和ANN方法（74.83%）。在噪声投资者识别这一特定用户画像研究任务中,通过利用深度用户表示学习引入文本内容特征,能够显著提升用户画像的各种评价指标。     

Object-relational data modelling for informetric databases

Informetric researchers have long chafed at the limitations of bibliographic databases for their analyses, without being able to visualize or develop real solutions to the problem. This paper describes a solution developed to provide for the specialist needs of informetric researchers. In a collaborative exercise between the fields of computer science and informetrics, data modelling was used in order to address the requirements of complex and dynamic informetric data. This paper reports on this modelling experience with its aim of building an object-relational database (ORDB) for informetric research purposes. The paper argues that ORM (object-relational model) is particularly suitable because it allows for the modelling of complex data and accommodates the various data source formats and standards used by a variety of bibliographic databases. Further, ORM captures the dynamic nature of informetric data by allowing user-defined data types and by embedding basic statistical calculating tools as object functions in these user-defined data types. The main ideas of the paper are implemented in an Oracle database management system.