484 research outputs found

    Bonding of reusable surface insulation with low density silicone foams

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    The development and evaluation of a reduced density, high reliable foamed bond strain isolation system for attaching reusable surface insulation to the space shuttle structure are reported. Included are data on virgin materials as well as on materials that received 100 cycles of exposure to 650 F for approximately 20 minutes per cycle. Room temperature vulcanizing silicon elastomers meet all the requirments for an adhesive bonding system

    Engaging Students with Constructivist Participatory Examinations in Asynchronous Learning Networks

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    The online participatory exam transforms the traditional exam into a constructivist, cooperative and engaging learning experience. Students learn from designing and answering exam questions, from evaluating their peers’ performance, and from reading questions, answers and evaluations. This paper, aimed at faculty who teach online and at researchers interested in online learning, describes the procedures, advantages, and disadvantages of this new approach to the examination process. Five semesters of participatory exam research are analyzed. A majority of students preferred the participatory exam and believed that it increased their learning

    Habitat use by caribou in northern Alberta, Canada

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    Habitat mapping and habitat supply assessment have been identified as key elements of the Alberta Woodland Caribou Conservation Strategy. Previous studies from northeastern Alberta have shown that caribou select lowland habitat types and avoid upland. The objectives of our study were to determine whether these selection patterns are consistent across all of northern Alberta and to generate a map of habitat suitability for the entire region. Our database included over 11 000 radiotelemetry locations collected over six years from caribou across northern Alberta. We also had available a recently revised map of peatlands for the entire province. We found that polygons in the peatland map containing greater than 30% bog were selected by caribou. Fens were also selected, but not as strongly as bogs. Habitat polygons containing greater than 50% non-peat were avoided. These findings were consistent among all regions studied, and among years. The proportion of caribou relocations declined exponentially with distance from polygons classified as peatlands. Based on the observed selection patterns, we reclassified the peatland map to reflect the potential suitability of habitat for caribou across northern Alberta

    Using Synthetic Worlds for Work and Learning

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    Synthetic worlds [Castronova 2005] are graphically-rich, three-dimensional (3D), electronic environments where members assume an embodied persona (i.e., avatars) and engage in socializing, competitive quests, and economic transactions with globally distributed others. Frequently categorized as technologies of play, synthetic worlds range from massively multiplayer online games (MMOGs) such as World of Warcraft, to virtual reality environments such as Second Life. Increasingly, educators, researchers and corporations are recognizing these 3D online spaces as legitimate communication media, thereby blurring the lines between work and play, and between reality and virtuality. In this panel, presented at the 2007 International Conference on Information Systems, we explore how the fluid work-play and reality-virtuality boundaries are negotiated and managed in practice. The panelists will rely on their research, conducted in educational, corporate and game environments, to address questions about learning, working and playing in these new media spaces

    Exploring Students’ Reactions to Virtual Worlds

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    Our research explores multi-user virtual environments for teaching university-level courses. This paper focuses on undergraduate students’ reactions to five virtual worlds explored as part of a Computers and Ethics course. Written reports from twenty-five students were qualitatively analyzed with respect to perceived ease of use, user satisfaction, and user concerns. Our preliminary findings indicate that students’ perceptions and attitudes were mixed. Some students perceived virtual worlds as relatively easy to use regarding object interactions, communication and user interaction. However, there were some instances of difficulty in navigation and in completing some tutorials. Furthermore, students expressed concerns beyond usability issues, such as user misbehavior and cheating. These issues could become significant barriers to using virtual worlds for college courses. We present suggestions for reducing such barriers

    Teaching lower level computer science courses via virtual classroom and video : course reports by faculty

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    New Jersey Institute of Technology is the grateful recipient of a generous grant from the Alfred P. Sloan Foundation which has enabled it to explore the use of asynchronous learning networks to create and deliver an entire undergraduate degree program in computer and information science. Each of these courses uses some amount of lecture-type material delivered via videotape. These materials are usually available to students in three different ways: by viewing broadcasts on a New Jersey cable station, by renting the set of videotapes, or by viewing in a special room in the library. Videotapes for distance learning are not new and are not, in themselves, a very effective means of delivery. The innovative part of this project is the Virtual Classroom™ which is a specially tailored set of features embedded in New Jersey Institute of Technology\u27s computer conferencing system, EIES (Electronic Information Exchange System). This makes possible a rich interchange and collaboration among students and faculty as they discuss and work through the problems and concepts in a course. As of the spring of 1995, both the B.A.I.S and the B.S.C.S. are available to distance and oncampus students. Teaching in a Virtual Classroom mixed with other media (such as video or CD ROM) is not simple however. The purpose of the enclosed descriptions of experiences by faculty members is to familiarize prospective teachers using this media mix in the future with both some ideas for how to organize their online activities, and knowledge of problems that have been encountered. The faculty members were given a suggested outline of topics to include in their reports, but otherwise were free to include whatever they thought would be of most use to other faculty members in the future, teaching the same or similar courses. Those who are interested in learning more about teaching and learning in ALN environments are referred to two book-length treatments: Starr Roxanne Hiltz, The Virtual Classroom: Learning Without Limits via Computer Networks (Ablex, Norwood NJ, 1994); and Linda Harasim, Starr Roxanne Hiltz, Lucio Teles and Murray Turoff, Learning Networks: A Field Guide to Teaching and Learning Online (MIT Press, 1995

    Nanopatterning Gold by Templated Solid State Dewetting on the Silica Warp and Weft of Diatoms

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    The diatom, Nitzschia palea, exhibits complex silica shell (frustule) topography that resembles the warp and weft pattern of woven glass. The surface is perforated with a rhombic lattice of roughly oblong pores between periodically undulating transverse weft costae. Exfoliated frustules can be used to template gold nanoparticles by thermally induced dewetting of thin gold films. Acting as templates for the process, the frustules give rise to two coexisting hierarchies of particle sizes and patterned distributions of nanoparticles. By examining temperature dependent dewetting of 5, 10, and 15 nm Au films for various annealing times, we establish conditions for particle formation and patterning. The 5 nm film gives distributions of small particles randomly distributed over the surface and multiple particles at the rhombic lattice points in the pores. Thicker films yield larger faceted particles on the surface and particles that exhibit shapes that are roughly conformal with the shape of the pore container. The pores and costae are sources of curvature instabilities in the film that lead to mass transport of gold and selective accumulation in the weft valleys and pores. We suggest that, with respect to dewetting, the frustule comprises 2-dimensional sublattices of trapping sites. The pattern of dewetting is radically altered by interposing a self-assembled molecular adhesive of mercaptopropyltrimethoxysilane between the Au film overlayer and the frustule. By adjusting the interfacial energy in this manner, a fractal-like overlay of Au islands coexists with a periodic distribution of nanoparticles in the pores

    Participatory Design for the Social Media Needs of Emergency Public Information Officers

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    ABSTRACT This paper describes the design, execution, and results of a participatory design workshop with emergency public information officers (PIOs). During the workshop, PIOs and researchers explored ideas and designs for supporting the social media needs of PIO work. Results indicate that PIO perceptions of social media have changed as they have learned to incorporate activities of the public into their work, yet they still struggle with issues of trust and liability. Based on workshop design activities, the paper offers a set of design recommendations for supporting the social media needs of PIO work practice such as the ability to monitor, document, and report social media activity
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