从布尔代数到布尔微积分

布尔函数作为最简单的有限值函数具有特殊的重要性．它在包括信息、控制等许多领域有着广泛的应用．本文综合介绍有关布尔函数的理论基础．包括从布尔代数到布尔微积分的主要理论结果,它们在信息与控制中的一些重要应用,以及其前沿动态与新进展．介绍的一个重点是矩阵半张量积在这些领域的应用．     

From individuals to populations: A mean field semantics for process algebra

A new semantics in terms of mean field equations is presented for WSCCS (Weighted Synchronous Calculus of Communicating Systems). The semantics captures the average behaviour of the system over time, but without computing the entire state space, therefore avoiding the state space explosion problem. This allows easy investigation of models with large numbers of components. The new semantics is shown to be equivalent to the standard Discrete Time Markov Chain semantics of WSCCS as the number of processes tends to infinity. The method of deriving the semantics is illustrated with examples drawn from biology and from computing.     

Dynamic consistency in process algebra: From Paradigm to ACP

The coordination modelling language Paradigm addresses collaboration between components in terms of dynamic constraints. Within a Paradigm model, component dynamics are consistently specified at various levels of abstraction. The operational semantics of Paradigm is given. For a large, general subclass of Paradigm models a translation into process algebra is provided. Once expressed in process algebra, relying on a correctness result, Paradigm models are amenable to process algebraic reasoning and to verification via the mCRL2 toolset. Examples of a scheduling problem illustrate the approach.     

From concepts to consistent object specifications: Translation of a domain-oriented feature framework into practice

A steady increase in consumer demands,and severe constraints from both a somewhat damaged environment and newly installed government policies,require today‘s product design and development to be faster and more efficient than ever before,yet utilizing even fewer resources.New holistic approaches,such at total product life cycle modeling which embraces all aspercts of a product‘s life cycle,are current attempts to solve these problems,Within the field of product design and modeling,feature technology has proved to be one very promising solution component.Owing to the tremendous increase in information technology,to transfer from low level data processing towards knowledge modeling and information processing is about to bring a change in almost every computerized application.From this viewpoint,current problems of both feature frameworks and feature systems are analyzed in respect to static and dynamic consistency breakdowns.The analysis ranges from early stager of designing(feature)concepts to final system implementation and application.For the first tie,an integrated view is given on approaches,solutions and practical experience,with feature concepts and structures,providing both a feature framework and its implementation with sufficient system architecture and computational power to master a fair number of known consistency breakdowns,while providing for robust contexts for feature semantics and integrated models.Within today;s heavy use of information technology these are pre-requisites if the full potential of feature technology is to be successfully translated into practice.     

The FLAME approach: From dense linear algebra algorithms to high-performance multi-accelerator implementations

Parallel accelerators are playing an increasingly important role in scientific computing. However, it is perceived that their weakness nowadays is their reduced “programmability” in comparison with traditional general-purpose CPUs. For the domain of dense linear algebra, we demonstrate that this is not necessarily the case. We show how the libflame library carefully layers routines and abstracts details related to storage and computation, so that extending it to take advantage of multiple accelerators is achievable without introducing platform specific complexity into the library code base. We focus on the experience of the library developer as he develops a library routine for a new operation, reduction of a generalized Hermitian positive definite eigenvalue problem to a standard Hermitian form, and configures the library to target a multi-GPU platform. It becomes obvious that the library developer does not need to know about the parallelization or the details of the multi-accelerator platform. Excellent performance on a system with four NVIDIA Tesla C2050 GPUs is reported. This makes libflame the first library to be released that incorporates multi-GPU functionality for dense matrix computations, setting a new standard for performance.     

From handheld collaborative tool to effective classroom module: Embedding CSCL in a broader design framework

The field of Computer Supported Collaborative Learning (CSCL) includes designers who emphasize effectiveness, measured via experiments, as well as designers who emphasize context and conduct qualitative research on teaching and learning practices. We conjectured that these two different emphases could be fruitful combined in a research and development process aimed at producing effective CSCL practices. We explored this possibility in a project that adapted a CSCL tool from Chile to serve as the basis of an effective 3-week classroom module for primary school mathematics in the United States. To go from tool to module, we addressed curricular fit, training materials, pedagogical guidance, formative and summative assessments, and logistical support. In conducting the project, we found that effectiveness and contextual research could be conducted simultaneously and yielded complementary insight to this design process, which enabled our project to rapidly move from the base tool towards complete classroom modules. An experiment we conducted after our design iterations showed that students who used the modules learned more about the target content, fractions. A retrospective analysis of our design process suggests that the Integrative Learning Design framework is useful for organizing the complementary components of effectiveness and contextual research in our design process.     

Supporting middle school students' online reading of scientific resources: moving beyond cursory,fragmented, and opportunistic reading

The abundant scientific resources on the Web provide great opportunities for students to expand their science learning, yet easy access to information does not ensure learning. Prior research has found that middle school students tend to read Web‐based scientific resources in a shallow, superficial manner. A software tool was designed to support middle school students in reading online scientific resources through three key strategies: making explicit a skim–read–summarize structure for online reading, using prompts to guide students' reading and foster articulation of thinking, and connecting reading to learning purposes. This study examined the differences between regular and guided online reading performed by eight pairs of sixth graders in a science inquiry project. The students' online reading processes and conversations were captured by a screen‐recording programme. Analysis of 60 h of screen videos showed that the students' online reading in the regular condition was cursory, fragmented, and opportunistic, while the structured online reading was more deliberate, thorough, and purposeful. Overall, the results suggest that middle school students' online reading of scientific resources needs to be guided.     

From SCORM to Common Cartridge: A step forward

Shareable Content Object Reference Model (SCORM) was proposed as a standard for sharable learning object packaging, delivering and sequencing. Several years later, Common Cartridge (CC) is proposed as an enhancement of SCORM offering more flexibility and addressing needs not originally envisioned, namely assessment and web 2.0 standards, content authorization, collaborative forums, outcomes reporting, accessibility. Educational policy makers, specialists responsible for learning systems deployment, educational content authors and teachers committed to the learning object paradigm must opt for or coexist with two different, partially overlapping proposals for content packaging. While SCORM was conceived for self-paced computer based learning, Common Cartridge attempts at providing support for all forms of teaching and learning with a stress on interactive and collaborative environments. Variety of content, distributed content, discussion forums, assessment, student’s tracking, interaction with external tools and authorization to access resources are listed as its main enhancements. This article reviews and compares SCORM and Common Cartridge from an educational perspective, seeking to provide some ground and guidelines on how to stand before these proposals. A simple process for authoring a Common Cartridge is described, as well as testing and conversion from SCORM. Suggestions are made to education practitioners on learning objects standards adoption in the most common scenarios.     

Cognitive perturbation through dynamic modelling: a pedagogical approach to conceptual change in science

While simulations have widely been used to facilitate conceptual change in learning science, results indicate that significant disparity or gap between students' prior conceptions and scientific conceptions still exists. To bridge the gap, we argue that the applications of computer simulation in science education should be broadened to enable students to model their thoughts and to improve and advance their theories progressively. While computer simulations are often used to offer opportunities for students to explore scientific models, they do not give them the space to explore their own conceptions, and thus cannot effectively address the challenge of changing students' alternative conceptions. Findings from our recent empirical study reveal that, firstly, dynamic modelling using the environment WorldMaker 2000 in conjunction with the use of a cognitive perturbation strategy by the teacher was effective in helping students to migrate from their alternative conceptions towards a more scientifically inclined one; secondly, the pathways of conceptual change across groups were idiosyncratic and diverse. Respecting students' ideas seriously and providing cognitive perturbation at appropriate junctures of the inquiry process are found to be conducive to fostering conceptual change. In this paper, we will report on the details of the pedagogical approach adopted by the teacher and portray how students' conceptions change during the entire process of model building.     

WebSail: From On-line Learning to Web Search

In this paper we report our research on building WebSail, an intelligent web search engine that is able to perform real-time adaptive learning. WebSail learns from the user's relevance feedback, so that it is able to speed up its search process and to enhance its search performance. We design an efficient adaptive learning algorithm TW2 to search for web documents. WebSail employs TW2 together with an internal index database and a real-time meta-searcher to perform real-time adaptive learning to find desired documents with as little relevance feedback from the user as possible. The architecture and performance of WebSail are also discussed. Received 3 November 2000 / Revised 13 March 2001 / Accepted in revised form 17 April 2001     

Integrating technology in the classroom: a visual conceptualization of teachers' knowledge, goals and beliefs

Abstract   In this paper, we devise a diagrammatic conceptualization to describe and represent the complex interplay of a teacher's knowledge (K), goals (G) and beliefs (B) in leveraging technology effectively in the classroom. The degree of coherency between the KGB region and the affordances of the technology serves as an indicator of the teachers' developmental progression through the initiation, implementation and maturation phases of using technology in the classroom. In our study, two teachers with differing knowledge, goals and beliefs are studied as they integrated GroupScribbles technology in their classroom lessons over a period of 1 year. Our findings reveal that the transition between the teacher's developmental states (as indicated by coherency diagrams) is nonlinear, and thus the importance of ensuring high coherency right at the initiation stage. Support for the teacher from other teachers and researchers remains an important factor in developing the teacher's competency to leverage the technology successfully. The stability of the KGB region further ensures smooth progression of the teacher's effective integration of technology in the classroom.     

From fever to flu: The rhetoric of reporting Asia in a Swedish business magazine

In this paper some aspects of the stereotyping of China and Japan are explored by using a sample of articles from a Swedish business magazine. The main objective is to show how stereotypes are adapted to capture new developments in economy and technology. During the years of high hopes for the largest Asian economies, stereotypes proved to be far from timeless and unchanging. Also a large number of metaphors were used to express perceived similarities between East and West, further undermining tradi-tional Western understanding of Asia as inert and eternally different. The recent decline of Japan put an end to this, creating a return to a vocabulary of cultural characterisations and explanations.     

A method to find all solutions of a system of multivariate polynomial equalities and inequalities in the max algebra

In this paper we show that finding solutions of a system of multivariate polynomial equalities and inequalities in the max algebra is equivalent to solving an Extended Linear Complementarity Problem. This allows us to find all solutions of such a system of multivariate polynomial equalities and inequalities and provides a geometrical insight in the structure of the solution set. We also demonstrate that this enables us to solve many important problems in the max algebra and the max-min-plus algebra such as matrix decompositions, construction of matrices with a given characteristic polynomial, state space transformations and the (minimal) state space realization problem.Research assistant with the N.F.W.O. (Belgian National Fund for Scientific Research).Senior research associate with the N.F.W.O.     

From Dewey to Gates: A model to integrate psychoeducational principles in the selection and use of instructional technology

The purpose of this article is to propose a model to integrate educational mastery principles that emphasize cooperative and learner-centered instruction in higher education with the new advances of instructional technology, and to present a pilot case study to exemplify the model. It is clear that in spite of tremendous efforts by colleges and universities to introduce instructional technology in the classroom, many faculty remain skeptical of the new technologies. It is suggested that in order for instructional technology to be widely accepted and used by faculty, the value of this technology to improve classroom instruction has to be proven. It is proposed that this can be achieved by applying learner-centered principles, in which the instructional objectives of the class are directly linked both to the needs of the student and the role of the instructor in the classroom, which in turn determine the appropriate type and use of instructional technology. It presents a pilot case study in which a technology was used to teach a basic psychology concept.     

The e-HUB evolution: From a Custom Software Architecture to a Software-as-a-Service implementation

New technological advances have enabled the creation of distributed collaborative industrial networks giving origin to new collaborative e-business models such as the Virtual Organisation (VO). These industrial networks require new Information and Communication Technologies Infrastructures (ICT-I) playing the intermediary role as the enablers of interoperation among their participant organisations. Furthermore, these networks require coordination and cooperation mechanism among its members which in turn can be supported through specific vertical applications deployed over a common platform. PyME CREATIVA was a project defined with the aim of playing the role of a service provider of an open technological platform named the e-HUB, providing a set of collaborative electronic solutions named the e-services, to support collaborative business processes among Small and Medium-sized Enterprises (SMEs). Till today, the e-HUB platform has proved to be a complete IT architecture able to satisfy SMEs technological requirements to get involved in collaborative business opportunities, nevertheless with the technology progress new opportunities appear to improve the way these e-services are delivered to the SMEs. This paper provides an insight into the benefits and implications of evolving the e-HUB architecture into new one based-on Software-as-a-Service (SaaS) premises.     

多智能体强化学习在城市交通网络信号控制方法中应用综述

交通信号控制系统在物理位置和控制逻辑上分散于动态变化的网络交通环境,将每个路口的交通信号控制器看作一个异质的智能体,非常适合采用“无模型、自学习、数据驱动”的多智能体强化学习（MARL）方法建模与描述。为了解该方法的研究现状、存在问题及发展前景,系统跟踪了多智能体强化学习在国内外交通控制领域的具体应用,包括交通信号MARL控制概念模型、完全孤立的MARL控制、部分状态合作的MARL和动作联动的MARL控制,分析其技术特征和代际差异,讨论了多智体强化学习方法在交通信号控制中的研究动向,提出了发展网络交通信号多智能体强化学习集成控制的关键问题在于强化学习控制机理、联动协调性、交通状态特征抽取和多模式整合控制。     

如何构建理实一体化实训室

国家对教育不断进行改革,科技教育、现代化教育、职业教育都有着很大的改观,为教育改善着环境,改善着就业的能力,让在校的学生可以在校期间与社会工作做准备,不脱节。同时也让学生更好地体验所学技能。针对高等教育、职业教育,构建理实一体化实训室,在国家示范校理实一体化教学中,从理实一体的掌握,运用起理实一体化实训室后,理实一体化教学构建才有效地调动资源,合理的管理进行分析。     

From public policy to family practices: researching the everyday realities of families' technology use at home

Informed by ‘critical’ approaches to ‘educational technology’, this paper aims to move away from presenting a ‘could’ and ‘should’ explanation of children learning with technology to a more nuanced, context‐rich analyses of how information and communication technologies (ICTs) are being used by technologically privileged families at home. Here, a critical approach means locating the findings within a framework, which not only includes reference to the policies and politics of educational technology, but also takes account of uneven, contested, and contradictory uses of ICT in everyday family life. To achieve this, the paper presents accounts of technology use in situ from eight case families. The data reveal that although ICTs were purchased for their perceived educational potential, how parents and children approached and used them in the home for learning was entwined with many other dimensions of social life. The findings suggest that there is a need to move beyond one‐dimensional debates, such as access to ICT ensures use, to more nuanced accounts that focus on the ‘messy’ realities of ICTs usage ‘as it happens’ in the home. In sum, more explicit empirically based information on ICT practices in the home need to be made available for policymakers and families.     

Six seconds to visualize the word: improving EFL learners' vocabulary through VVVs

This paper moves away from reminiscent mechanical repetition and drills, which were in vogue when teaching vocabulary before the rise of technology. With the support of technology, innovative methodologies that are more effective and enjoyable can be implemented into vocabulary teaching. In this particular context, there seems to be a lack of technology integration in vocabulary teaching because of teachers being untrained and/or not provided with the necessary technology. The aim of this study was to foster vocabulary development through the implementation of Vine vocabulary videos in English vocabulary learning. An embedded mixed methods design was employed to collect necessary data for analysis. The results of the post‐test revealed that the practice of Vine vocabulary videos was effective and improved participants' vocabulary. The content analysis of the semi‐structured interviews carried out with participants indicated that they had enjoyed the whole process and found it very motivating and effective. This study claims that adopting smartphones into a vocabulary course will enable English as a foreign language learners to expand and consolidate their vocabulary learning outside the classroom, engage them in a collaborative learning environment, practice and use the language being learnt and share their knowledge and experiences with their peers.     

Performance,cognitive load,and behaviour of technology‐assisted English listening learning: From CALL to MALL

This study examines differences in English listening comprehension, cognitive load, and learning behaviour between outdoor ubiquitous learning and indoor computer‐assisted learning. An experimental design, employing a pretest‐posttest control group is employed. Randomly assigned foreign language university majors joined either the experimental group (outdoor ubiquitous learning), with 80 participants (26 males and 54 females), or a control group (indoor computer‐assisted learning), with 80 participants (27 males and 53 females). The experiment lasted 3 weeks. Both groups were administered a test of English listening proficiency before and after the experiment along with a questionnaire of cognitive load postexperiment. Prior English listening proficiency forms a covariate for the multivariate analysis of covariance. Results show (a) students in the experimental group exhibit significantly better English listening comprehension after the experiment compared to the control group; (b) students in the experimental group reported significantly lower cognitive load than the control group; (c) English listening comprehension and cognitive load exhibited a statistically significant negative relationship; and (d) outdoor ubiquitous learning enhanced self‐reported learning interests and interactions more than indoor computer‐assisted learning. Contributions and significances of this study are presented based on these results. Finally, implications for teaching practices are proposed.