188,047 research outputs found
Towards a semantic modeling of learners for social networks
No full textThe Friend of a Friend (FOAF) ontology is a vocabulary for mapping social networks. In this paper we propose an extension to FOAF in order to allow it to model learners and their social networks. We analyse FOAF alongside different learner modeling standards and specifications, and based on this analysis we introduce a taxonomy of the different features found in those models. We then compare the learner models and FOAF against the taxonomy to see how their characteristics have been shaped by their purpose. Based on this we propose extensions to FOAF in order to produce a learner model that is capable of forming the basis of a semantic social network.<br/
Intrinsic limits of J/sub c/ in composite metallic/Bi(Pb)-2223 multifilamentary tapes with twisted filaments
No full textThe intrinsic limits of Jc in composite Bi(Pb)-2223 multifilamentary tapes due to the reduction of the effective cross section and the enlargement of the twisted filaments have been analysed. A simple model of the twisted filaments as elliptic helices grouped in concentric shells have been used to derived analytical results for the intrinsic variation of Jc with the twist pitch, tp. In tapes with high thickness to width aspect ratios and large tp values, this model predicts a linear dependence of Jc with 1/tp, when the shape and superconducting filling factor of the tapes are constant. The Jc(tp) values depend on a set of parameters that define the helices, which may be derived from the analysis of the morphology of the filaments inside the tapes. To assess the model we have compared the predictions with the results here reported on Ag and Ag0.94Au0.06 alloy sheathed tapes with 19 and 37 twisted filaments, respectively. In tapes with high Jc, we have found a good agreement between the variation of Jc with tp experimentally measured and the intrinsic limits imposed by the filament geometr
Emergence and Collapse of Peace with Friend Selection Strategies
No full textA society consisting of agents who can freely choose to attack or not to attack others inevitably evolves into a battling society (a \'war of all against all\'). We investigated whether strategies based on C. Schmitt\'s concept of the political, the distinction of a friend and an enemy, lead to the emergence and collapse of social order. Especially, we propose \'friend selection strategies\' (FSSs), one of which we called the \'us-TFT\' (tit for tat) strategy, which requires an agent to regard one who did not attack him or his \'friends\' as a \'friend\'. We carried out evolutionary simulations on an artificial society consisting of FSS agents. As a result, we found that the us-TFT results in a peaceful society with the emergence of an us-TFT community. In addition, we found that the collapse of a peaceful society is triggered by another FSS strategy called a \'coward\'.Community, Carl Schmitt, a Friend and an Enemy, Tit for Tat, Coward, Evolutionary Simulation
Letter from A. C. Van Raalte to Honorable Friend
No full textA letter of Albertus C. Van Raalte to Honorable Friend in which Van Raalte discusses housing costs. This week again four families arrived here from the colony at Kalamazoo. Is the honorable friend Paulus den Bleyker? See Van Raalte\u27s letter to den Bleyker of 11 March 1851 in regard to housing. Van Raalte, at this time, is hoping the den Bleyker will move to Holland.https://digitalcommons.hope.edu/vrp_1850s/1197/thumbnail.jp
Letter from the Business Editor to E. C. Garman
No full textLetter from the Business Editor of Our Florida Friend to E. C. Garman. The one-page typewritten letter is dated 29 November 1912
Letter from the Business Editor to C. H. Lamb
No full textLetter from the Business Editor of Our Florida Friend to C. H. Lamb. The one-page typewritten letter is dated 23 November 1912
Letter from President O. C. Carmichael, University of Alabama, to Friend, September 14, 1956
No full textFinite element modeling of thermal stability and quench propagation in a pancake coil of PbBi2223 tapes
No full textThe initiation and propagation of quench events in a high temperature superconducting (HTS) pancake coil were modeled using finite element software package ANSYS. The nonlinear temperature dependent heat generation in HTS composite over a wide current sharing range is calculated based on power-law E-J characteristics with temperature dependence of the n-value and critical current density. Thermal properties of the HTS composite and coil sections were measured and compared with estimated values based on data for individual coil components and the fill factor of the coil construct. The effect of replacing the complex coil winding structure with an effective continuum was investigated by examining the normal zone temperature profiles and minimum quench energy (MQE). With reducing operating temperature from 77 K to 30 K, MQE reduces correspondingly from 30 J to 15 J. Simulation results are found in satisfactory agreement with experimental results from a test coil wound with PbBi2223 tape
- …
