Using log variables in a learning management system to evaluate learning activity using the lens of activity theory

As the advance of learning technologies and analytics tools continues, learning management systems (LMSs) have been required to fulfil the growing expectations for smart learning. However, the reality regarding the level of technology integration in higher education differs considerably from such expectations or the speed of advances in educational technologies. This research aimed to evaluate the current activation levels and usage patterns of a LMS. A large data-set was analysed, which included the online activity information from 7940 courses. Through data pre-processing, general indicators reflecting login frequencies of the virtual campus and activity-based indicators presenting the activation patterns of diverse functions provided by Moodle were derived. Activity theory was applied to interpret the results of analysis, since it has been recognised as a powerful framework to understand phenomena encompassing interactive systems. Further, time-series investigation over three consecutive semesters allowed observation of historical changes. The results revealed considerably low use of the virtual campus with only slight changes, as well as significantly different activity patterns across course attributes and colleges. Contradictions among components in the activity system are discussed, along with the implications for improving teaching and learning with LMS in higher education.     

How pre-service teachers navigate trade-offs of food systems across time scales: a lens for exploring understandings of sustainability

In response to the increasing recognition of the need for sustainable food systems, research on students’ and educators’ knowledge of food systems and sustainability more broadly has grown but has generally focused on what people ‘fail’ to understand. Moving away from this deficit approach, the present study used semi-structured interviews to explore how 12 pre-service teachers (PSTs) in the US consider sustainability in terms of the trade-offs – or concurrent costs and benefits – associated with using different agricultural resources over short, medium, and long terms. Drawing upon the constructs of framing, metacognition, and complex causality, the study found that the majority of PSTs referred to indirect experiences of seeing or hearing about agricultural resources to demonstrate stable knowledge of short-term trade-offs and construct tentative knowledge about medium-term trade-offs. Few described long-term trade-offs. Most participants also acknowledged some gaps in their knowledge in discussing trade-offs across the different time scales. Findings suggest the importance of leveraging and building upon educators’ (and ultimately students’) prior experiences to build their understanding of complex trade-offs that underlie food systems. The study also illustrates the value of using the concept of trade-offs across time scales to explore people’s conceptions and understandings of sustainability.     

数据析取系统的概念模式及其在客户关系管理中的应用

本文对决策支持系统从管理信息系统析取数据的有关问题进行研究。提出了数据析取系统的四种模式，研究了它们的实现方式，并介绍了在客户关系管理中的应用。     

基于耗散与灰关联熵的RIS演化机制研究

 本文在论证区域创新系统(RIS)是一种耗散结构的基础上，以各评价创新能力的指标为序参量，来描述RIS的有序性和演化方向。应用耗散结构理论和灰色系统理论，把灰关联度和熵结合起来，以序参量为基础，建立了基于灰关联熵的RIS演化方向判别模型，并以黑龙江省为例对该模型的研究结果进行了验证，为RIS分析提供了一种崭新的研究思路。     

实现"或逻辑"线性约束的结构型控制器设计方法综述

基于受控Petri网的离散事件监控器按实现形式可分为逻辑型控制器和结构型控制器．由于结构型控制器具有控制动作的计算速度快，被控对象和监控器的描述形式统一等优点，而受到很多研究人员的青睐．然而，由于“或逻辑”线性约束条件的非凸状态空间的本质，用结构型控制器实现该线性约束条件将比较困难．在本文中，作者首先回顾了这一问题的起源及其意义，接着详细讨论了当前用结构型控制器实现该类状态规范的主流方法及它们各自存在的优缺点，并就某些方法提出了改进措施．最后，作者对今后的研究方向进行了预测和展望．     

系统生物学研究进展

人类基因组计划把生物学由分子生物学时代推向系统生物学时代,生物学由分解转向整合,由叙述科学转变为定量预测科学。     

Sampling and control of switched linear systems

In this paper, we address the sampling and control issues for switched linear systems. Under synchronous switching and piecewise constant control, a continuous-time switched system is naturally related to a discrete-time sampled-data system. We prove that, with almost any sampling rate, the controllable subspace will be preserved for a switched linear system. We also investigate the possibility of achieving controllability using regular switching mechanisms. We show that, to achieve controllability for a switched linear system, it is sufficient to use cyclic and synchronous switching paths and constant control laws.     

适用于中尺度系统研究的位涡方程

本文通过推导绝热、无摩擦大气方程组，讨论了新方程组的特点；新方程组中，位温 显式出现在动量方程中，有利于探讨倾斜的等熵面（等位温面）对中尺度系统发生和发展的影响。进一步，利用此新方程组，推导出适用于中尺度系统研究的新的位涡方程，新位涡方程突出的特点是，与中尺度系统发生、发展密切相关的散度项显式出现在方程的右端；这为研究中尺度系统演变过程中，辐合、辐散效应对系统位涡收支的影响、进而研究中尺度系统发生、发展的热、动力学过程提供了方法。     

Combining entrepreneurial and scientific performance in academia: towards a compounded and reciprocal Matthew-effect?

The increase of entrepreneurial activity within academia has raised concerns that the research orientation of universities might become ‘contaminated’ by the application-oriented needs of industry. Empirical evidence on this concern is scarce and ambiguous. We examine whether entrepreneurial and scientific performance in academia can be reconciled. Our empirical findings (KU Leuven, Belgium) suggest that both activities do not hamper each other; engagement in entrepreneurial activities coincides with increased publication outputs, without affecting the nature of the publications involved. As resources increase, this interaction becomes more significant, pointing towards a Matthew-effect. We finally suggest that balancing both activities further depends on the institutional policies deployed.