Simple e-learning semantic tool

Copyright © 2010 Stanford Center for Biomedical Informatics ResearchIn this paper we introduce a simple e-learning tool (SET) that can be used by students, teachers and librarians to build, evaluate, maintain and test knowledge of an arbitrary domain terminology. The core of the tool is a conceptual model developed in Protégé. The knowledge base used for testing the tool is from the Business Strategies domain and it contains more than 10,000 definitions from domain experts. The main advantages of using Protégé were in providing a valid and consistent structure for the initial set of largely unstructured data and in generating interfaces for the tool implementation. Compared to the other on-line glossaries, the emphasis here is on quality, by using domain expert knowledge; on diversity of that knowledge (a typical term will be accompanied with two or more definitions from different sources) and on simple to use additional e-learning features such as definition search, essay “helper”, visual domain explorer, test generator, etc. The related work has mainly been focused on the following areas, namely - development of domain ontologies, development of ontologies of learning resources 1 (e.g. Chimera’s Project Delta, as described in Gardner, 2007) and development of on-line glossaries (e.g. Merriam Webster Online ) and encyclopaedias (e.g. Wikipedia) . Our work differs from each of the above mentioned in that it builds on development of a general and reusable glossary ontology that uses as instances, definitions taken from domain textbooks and refereed journals. In addition to that, we provide an application built on top of this ontology that can be used as a cognitive support tool

Effective charging energy for a regular granular metal array

We study the Ambegaokar-Eckern-Sch\"{o}n (AES) model for a regular array of metallic grains coupled by tunnel junctions of conductance $g$ and calculate both paramagnetic and diamagnetic terms in the Kubo formula for the conductivity. We find analytically, and confirm by numerical path integral Monte Carlo methods, that for $0<g<4$ the conductivity obeys an Arrhenius law $\sigma(T)\sim\exp[-E^{*}(g)/T]$ with an effective charging energy $E^{*} (g)$ when the temperature is sufficiently low, due to a subtle cancellation between $T^2$ inelastic-cotunneling contributions in the paramagnetic and diamagnetic terms. We present numerical results for the effective charging energy and compare the results with recent theoretical analyses. We discuss the different ways in which the experimentally observed $\sigma(T)\sim\exp[-\sqrt{T_{0}/T}]$ law could be attributed to disorder.Comment: 5 pages, 3 figures, ReVTeX; added estimates of effective charging energies and discussion of effects of disorde