3,566 research outputs found

    An architecture of a user-centred digital library for the academic community

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    An architecture of a user-centred digital library, designed to lead users of an academic community to the required information resources based on their tasks, is proposed. Information resources include full-text articles, databases, theses and dissertations, e-journals, e-books, multimedia databases, and so on. Other information resources such as university course calendars, university statutes, course registration, thesis and dissertation guidelines, style guides, and so on, are also needed by users. A prototype has been designed and developed using the School of Computer Engineering at Nanyang Technological University (NTU) as an example of such an environment to provide access to these information resources which are spread across different servers and in different home pages This prototype provides links to various information resources according to users' needs, as well as a personal work space to record/store his/her publications, frequently used or favorite hyperlinks and references or notes. Various stages of the prototype design and development are described and future works on this line are highlighted

    Reasoning about Action: An Argumentation - Theoretic Approach

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    We present a uniform non-monotonic solution to the problems of reasoning about action on the basis of an argumentation-theoretic approach. Our theory is provably correct relative to a sensible minimisation policy introduced on top of a temporal propositional logic. Sophisticated problem domains can be formalised in our framework. As much attention of researchers in the field has been paid to the traditional and basic problems in reasoning about actions such as the frame, the qualification and the ramification problems, approaches to these problems within our formalisation lie at heart of the expositions presented in this paper

    A comparative study of paragenesis, geochemistry and fluid inclusions of selected primary tin deposits of West Malaysia

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    Algebraic, geometric, and stochastic aspects of genetic operators

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    Genetic algorithms for function optimization employ genetic operators patterned after those observed in search strategies employed in natural adaptation. Two of these operators, crossover and inversion, are interpreted in terms of their algebraic and geometric properties. Stochastic models of the operators are developed which are employed in Monte Carlo simulations of their behavior

    Charge-ordering, commensurability and metallicity in the phase diagram of layered Na(x)CoO(2)

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    The phase diagram of non-hydrated Na(x)CoO(2) has been determined by changing the Na content x using a series of chemical reactions. As x increases from 0.3, the ground state goes from a paramagnetic metal to a charge-ordered insulator (at x=1/2) to a `Curie-Weiss metal' (around 0.70), and finally to a weak-moment magnetically ordered state (x>0.75). The unusual properties of the state at 1/2 (including particle-hole symmetry at low T and enhanced thermal conductivity) are described. The strong coupling between the Na ions and the holes is emphasized.Comment: 4 pages with 3 figures, changed conten

    Pressure effects in the triangular layered cobaltites NaxCoO2

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    We have measured transport properties as a function of temperature and pressure up to 30GPa in the NaxCoO2 system. For the x=0.5 sample the transition temperature at 53K increases with pressure, while paradoxically the sample passes from an insulating to a metallic ground state. A similar transition is observed in the x=0.31 sample under pressure. Compression on the x=0.75 sample transforms the sample from a metallic to an insulating state. We discuss our results in terms of interactions between band structure effects and Na+ order.Comment: 18 pages, 5 figure

    A Novel Taxonomy of Opportunities and Risks in Massively Multiplayer Online Role Playing Games

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    The explosion and rapid embrace of Massively Multiplayer Online Role Playing Games (MMORPG) has provided players with unique, fully immersive three dimensional environments in which they can express themselves in a myriad of ways. Players can develop unique skill sets, share knowledge, explore and experiment with various identities and network with like-minded individuals. Evidence suggests however, that these opportunities are accompanied with a number of risks including addiction, desensitisation and threats to the privacy of personal information. This paper presents a novel Taxonomy of opportunities and risks in the specific context of Massively Multiplayer Online Role Playing Games

    Optical evidence for the proximity to a spin-density-wave metallic state in Na0.7_{0.7}CoO2_2

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    We present the optical properties of \na single crystals, measured over a broad spectral range as a function of temperature (TT). The capability to cover the energy range from the far-infrared up to the ultraviolet allows us to perform reliable Kramers-Kronig transformation, in order to obtain the absorption spectrum (i.e., the complex optical conductivity). To the complex optical conductivity we apply the generalized Drude model, extracting the frequency dependence of the scattering rate (Γ\Gamma) and effective mass (mm^*) of the itinerant charge carriers. We find that Γ(ω)ω\Gamma(\omega)\sim \omega at low temperatures and for ω>T\omega > T. This suggests that \na is at the verge of a spin-density-wave metallic phase
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