177,120 research outputs found

    Design and implementation of the feedback systems Web laboratory

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 99-103).This thesis describes the design and implementation of a remote web-based laboratory (WebLab) for MIT's 6.302 Feedback Systems course. The WebLab system proposed consists of a three-tiered architecture where client and server communicate with each other via web services. On the front end, the user interacts with the system through the Lab Client's graphical user interface implemented as a Java applet. On the back end, the Lab Server processes experiment requests from users and runs them at the laboratory site. Once the experiment has been completed successfully, the Lab Server sends the measured data to the Lab Client for display on the screen and further manipulation by the user. Furthermore, the WebLab is designed to take advantage of the iLab framework for provision of authentication and authorization services, as well as common administrative tasks, such as user management and logging of experimental results.by Gerardo Viedma Núñez.M.Eng

    Implementation and design of a service-based framework to integrate personal and institutional learning environments

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    The landscape of teaching and learning has changed in recent years because of the application of Information and Communications technology. Among the most representative innovations in this regard are Learning Management Systems. Despite of their popularity in institutional contexts and the wide set of tools and services that they provide to learners and teachers, they present several issues. Learning Management Systems are linked to an institution and a period of time, and are not adapted to learners' needs. In order to address these problems Personal Learning Environments are defined, but it is clear that these will not replace Learning Management Systems and other institutional contexts. Both types of environment should therefore coexist and interact. This paper presents a service-based framework to facilitate such interoperability. It supports the export of functionalities from the institutional to the personal environment and also the integration within the institution of learning outcomes from personal activities. In order to achieve this in a flexible, extensible and open way, web services and interoperability specifications are used. In addition some interoperability scenarios are posed. The framework has been tested in real learning contexts and the results show that interoperability is possible, and that it benefits learners, teachers and institutions.Peer ReviewedPostprint (author's final draft

    Global Teamwork: A Study of Design Learning in Collaborative Virtual Environments

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    With the recent developments in communication and information technologies, using Collaborative Virtual Environments (CVEs) in design activity has experienced a remarkable increase. In this paper we present a collaborative learning activity between the University of Sydney (USYD), and the Istanbul Technical University (ITU). This paper shares our teaching experience and discusses the principles of collaborative design learning in virtual environments. Followed by a study on students’ perception on the courses and collaborative learning in both universities, this paper also suggests future refinements on the course structure and the main areas of collaborative design learning. Keywords: Collaborative Design; Collaborative Virtual Environments; Design Teaching And Learning</p

    Kompics: a message-passing component model for building distributed systems

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    The Kompics component model and programming framework was designedto simplify the development of increasingly complex distributed systems. Systems built with Kompics leverage multi-core machines out of the box and they can be dynamically reconfigured to support hot software upgrades. A simulation framework enables deterministic debugging and reproducible performance evaluation of unmodified Kompics distributed systems. We describe the component model and show how to program and compose event-based distributed systems. We present the architectural patterns and abstractions that Kompics facilitates and we highlight a case study of a complex distributed middleware that we have built with Kompics. We show how our approach enables systematic development and evaluation of large-scale and dynamic distributed systems

    E-BioFlow: Different Perspectives on Scientific Workflows

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    We introduce a new type of workflow design system called\ud e-BioFlow and illustrate it by means of a simple sequence alignment workflow. E-BioFlow, intended to model advanced scientific workflows, enables the user to model a workflow from three different but strongly coupled perspectives: the control flow perspective, the data flow perspective, and the resource perspective. All three perspectives are of\ud equal importance, but workflow designers from different domains prefer different perspectives as entry points for their design, and a single workflow designer may prefer different perspectives in different stages of workflow design. Each perspective provides its own type of information, visualisation and support for validation. Combining these three perspectives in a single application provides a new and flexible way of modelling workflows

    IREEL: remote experimentation with real protocols and applications over emulated network

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    This paper presents a novel e-learning platform called IREEL. IREEL is a virtual laboratory allowing students to drive experiments with real Internet applications and end-to-end protocols in the context of networking courses. This platform consists in a remote network emulator offering a set of predefined applications and protocol mechanisms. Experimenters configure and control the emulation and the end-systems behavior in order to perform tests, measurements and observations on protocols or applications operating under controlled specific networking conditions. A set of end-to-end mechanisms, mainly focusing on transport and application level protocols, are currently available. IREEL is scalable and easy to use thanks to an ergonomic web interface

    Data Driven Surrogate Based Optimization in the Problem Solving Environment WBCSim

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    Large scale, multidisciplinary, engineering designs are always difficult due to the complexity and dimensionality of these problems. Direct coupling between the analysis codes and the optimization routines can be prohibitively time consuming due to the complexity of the underlying simulation codes. One way of tackling this problem is by constructing computationally cheap(er) approximations of the expensive simulations, that mimic the behavior of the simulation model as closely as possible. This paper presents a data driven, surrogate based optimization algorithm that uses a trust region based sequential approximate optimization (SAO) framework and a statistical sampling approach based on design of experiment (DOE) arrays. The algorithm is implemented using techniques from two packages—SURFPACK and SHEPPACK that provide a collection of approximation algorithms to build the surrogates and three different DOE techniques—full factorial (FF), Latin hypercube sampling (LHS), and central composite design (CCD)—are used to train the surrogates. The results are compared with the optimization results obtained by directly coupling an optimizer with the simulation code. The biggest concern in using the SAO framework based on statistical sampling is the generation of the required database. As the number of design variables grows, the computational cost of generating the required database grows rapidly. A data driven approach is proposed to tackle this situation, where the trick is to run the expensive simulation if and only if a nearby data point does not exist in the cumulatively growing database. Over time the database matures and is enriched as more and more optimizations are performed. Results show that the proposed methodology dramatically reduces the total number of calls to the expensive simulation runs during the optimization process

    Information system support in construction industry with semantic web technologies and/or autonomous reasoning agents

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    Information technology support is hard to find for the early design phases of the architectural design process. Many of the existing issues in such design decision support tools appear to be caused by a mismatch between the ways in which designers think and the ways in which information systems aim to give support. We therefore started an investigation of existing theories of design thinking, compared to the way in which design decision support systems provide information to the designer. We identify two main strategies towards information system support in the early design phase: (1) applications for making design try-outs, and (2) applications as autonomous reasoning agents. We outline preview implementations for both approaches and indicate to what extent these strategies can be used to improve information system support for the architectural designer
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