Exploring teachers' perceptions on different CSCL script editing tools

Despite the apparent maturity of the learning design field, and the variety of tooling available to support it, adoption among the teacher community (one of its alleged main targets) is still low. There is a lack of research on teachers' perception and use of different technological learning design tools, as existing evaluations are often restricted to a single tool. In order to explore whether there are common factors hampering teacher adoption, and which tool features might appeal to different teachers, more studies involving multiple authoring tools are needed. This paper provides a first step in this direction, describing a mixed methods study performed around a professional development workshop with 18 university teachers from multiple disciplines. This workshop exposed teachers to two different authoring tools (WebCollage and EDIT2), as they learned to create computer-supported collaborative learning (CSCL) designs and implement them. The findings of our interpretive study (which included questionnaires, observations, or group discussion recordings) support the idea that there is no single tool or set of features that are globally perceived as better, although our evidence also highlights certain factors as important for participant teachers – amongst others, the integration of learning designs with the ICT platforms for enactment, as well as with other tools that they already use in their everyday practice.     

Guaranteed cost control analysis and iterative design for constrained Takagi–Sugeno systems

This paper presents a novel control design technique in order to obtain a guaranteed cost fuzzy controller subject to constraints on the input channel. This guaranteed cost control law is obtained via multi-parametric quadratic programming. The result is a piecewise fuzzy control law where the state partition is defined by fuzzy inequalities. The parameters of the Lyapunov function can be obtained previously using Linear Matrix Inequalities optimization.     

基于可行域的遗传约简算法

在已有的遗传属性约简算法的基础上，通过引入约简的可行域概念，提出了基于可行域的遗传约简算法．可行域保持系统的分类能力，缩小了原问题的搜索空间，进而减小了问题的复杂度．适应度函数中引入与互信息相关的惩罚因子保证了算法在可行域中搜索．实验结果表明谊算法既克服了启发性算法的缺陷，较之已有的基于遗传算法的约简算法也有效率改进．     

Can openness to ICT and scientific research predict the ICT skills and ICT use of bachelor's students?

In this article, we focus on the question of why some bachelor's students have more proficiency in ICT skills and use computers and the Internet more frequently than other students do. To answer this question, we rely on the core variables of the TAM (Technology Acceptance Model), on the orientation of students toward scientific research, and on contextual factors. TAM has been applied successfully in research before, but in this article, the model is expanded with variables regarding the orientation of students toward scientific research, and is geared towards the relationship to basic ICT skills and the sustained use of these skills. In order to attain a more reliable instrument to measure proficiency in ICT skills and the frequency of ICT use, several new instruments are constructed. The results show that this model, a combination of four basic TAM variables, together with the identity commitment of students focused on the appreciation of scientific research and some context variables, can explain a substantial proportion of the variance in different ICT skills, but considerably less of the frequency of ICT use.     

A Heuristic algorithm to solve the unit commitment problem for real-life large-scale power systems

One of the main needs that power system operators around the world have is to solve complex Unit Commitment models for large-scale power systems in an acceptable computation time. This Paper presents an alternative Heuristic algorithm that successfully addresses this need. The Heuristic algorithm makes use of various optimization techniques such as Mixed Integer Linear Programming (MILP), Quadratic Programming (QP), Quadratically Constrained Programming (QCP), and Dynamic Programming (DP). CPLEX 12.2 is used as the main optimization engine for MILP, QP, and QCP. DP is an in-house algorithm used to obtain the commitment of Combined Cycle Plants (CCPs) when represented with the component-based model. This Heuristic algorithm combines the global optimality capabilities of MI (L) P formulations with the highly detailed models available for CCPs using LR–DP formulations. The Heuristic algorithm introduced in this Paper is capable of solving up to 1-week scenarios with a 1-hour time window for the complex Mexican Power System.     

Energy consumption and real GDP in G-7: Multi-horizon causality testing in the presence of capital stock

This paper applies two recent time series methods to re-examine the causal relationship among energy consumption, real GDP and capital stock in G-7 countries. These methods, the Dufour et al. [2006, Journal of Econometrics, 132:337–362] multiple horizon causality testing and the Hill [2007, Journal of Applied Econometrics, 22:747–765] sequential causality testing allow to test for (non)causality in a multivariate framework and can further reveal the time profile of causal effects, the presence of causation delays and the direct or indirect nature of the causal effects. Given the trending nature of the time series employed, we further take into account the presence of structural breaks in the form of trend changes. Our empirical results show that multi-horizon causality testing does uncover crucial information with respect to the dynamic interaction among energy consumption, real GDP and capital stock, while structural breaks do exist and appear to be critical for causality inference. In regard to causality direction, we find that real GDP dominates in anticipating energy consumption in G-7 countries.     

A fuzzy multicriteria evaluation system for the assessment of tunnels vis-à-vis surface roads: theoretical aspects—part I

In current practice, the most frequently used quantitative parameter for the selection between a road tunnel and a surface road, is the construction cost. Other parameters that could be of interest to a decision-maker are either absent or existing in a purely qualitative form that does not lend itself for comparisons between alternative solutions. For this reason, a tailor-made methodology was developed, aiming to facilitate the comparative assessment of road tunnels against surface roads on an overall basis. This methodology is based upon the principles of MultiCriteria (MCA) and Cost–Benefit Analysis (CBA), incorporating the full range of cost, technical, operational, environmental and spatial criteria required for the proper evaluation of the two alternatives.     

Nonparametric Dynamic Curve Monitoring

Rapid sequential comparison between the longitudinal pattern of a given subject and a target pattern has become increasingly important in modern scientific research for detecting abnormal activities in many data-rich applications. This article focuses on this problem when observations are collected sequentially with uncorrelated or correlated noise involved. A dynamic monitoring procedure is developed after connecting the curve monitoring problem to curve comparison. Under the framework of generalized likelihood ratio testing, we suggest a new exponentially weighted moving average (EWMA) control chart that can accommodate unequally spaced design points. An adaptive parameter selection feature is built in the proposed control chart so that the chart can detect a wide range of longitudinal pattern shifts effectively. To furnish fast computation, recursive formulas are derived for computing the charting statistic. Numerical studies show that the proposed method can deliver a satisfactory performance, and it outperforms existing methods in various cases. An example from the semiconductor manufacturing industry is used for the illustration of its implementation. Supplementary materials for this article are available online.     

Vehicle routing problem with time-varying speed

Vehicle routing problem with time-varying speed ( VRPTS) is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day. This paper proposes a simple model for estimating time-varying travel speeds in VRPTS that relieves much burden to the data-related problems. The study further presents three heuristics ( saving technique,proximity priority searching technique,and insertion technique) for VRPTS,developed by extending and modifying the existing heuristics for conventional VRP. The results of computational experiments demonstrate that the proposed estimation model performs well and the saving technique is the best among the three heuristics.