21,695 research outputs found

    Encountering soviet geography: oral histories of British geographical studies of the USSR and Eastern Europe 1945-1991

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    This paper considers the history of British geographical studies of the USSR and Eastern Europe 1945-1991, presenting material from a research project which has included thirty-two oral history interviews. Oral history is an especially fruitful research methodology in this context due to the distinct issues of formality and informality involved in researching the Soviet bloc. After discussing the nature of the subdiscipline and the Cold War context, including the role of the British state in shaping the field, the paper considers the role of formal academic meetings and exchanges, and the place of unofficial spaces of encounter in the formation of an intellectual culture. The paper concludes by reflecting on the merits of oral history in studies of the production of geographical knowledge

    Layered classification techniques for remote sensing applications

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    The layered classifier method is outlined and several applications to pattern classification for which the approach is suited are discussed

    Massive relic neutrinos in the galactic halo and the knee in the cosmic ray spectrum

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    Despite many efforts to find a reasonable explanation, the origin of the "knee" in the cosmic ray spectrum at energy around 10**15.5 eV remains mysterious. In this letter we suggest that the "knee" may be due to a GZK-like effect of cosmic rays interacting with massive neutrinos in the galactic halo. Simple kinematics connects the location of the "knee" with the mass of the neutrinos, and, while the required interaction cross section is larger than that predicted by the Standard Model, it can be accommodated by a small neutrino magnetic dipole moment. The values for the neutrino parameters obtained from the analysis of existing experimental data are compatible with present laboratory bounds.Comment: 8 pages, 1 figure, uses RevTe

    Implementation of ILLIAC 4 algorithms for multispectral image interpretation

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    Research has focused on the design and partial implementation of a comprehensive ILLIAC software system for computer-assisted interpretation of multispectral earth resources data such as that now collected by the Earth Resources Technology Satellite. Research suggests generally that the ILLIAC 4 should be as much as two orders of magnitude more cost effective than serial processing computers for digital interpretation of ERTS imagery via multivariate statistical classification techniques. The potential of the ARPA Network as a mechanism for interfacing geographically-dispersed users to an ILLIAC 4 image processing facility is discussed

    Supplier selection in risk consideration: a fuzzy based topsis approach

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    Supplier selection, the process of finding the right suppliers who are able to provide the buyer with the right quality products and/or services at the right price, at the right time and in the right quantities, is one of the most critical activities for establishing an effective supply chain. In classical Multi-Criteria Decision Making (MCDM) methods, the ratings and the weights of the criteria are known precisely. Owning to vagueness of the decision data, the crisp data are inadequate for real-life situations. Since human judgments including preferences are often vague and cannot be expressed by exact numerical values, the application of fuzzy concepts in decision making is deemed to be relevant. On the other hand, it is a hard problem since supplier selection is typically a MCDM problem involving several conflicting criteria on which decision maker’s knowledge is usually vague and imprecise. In the present work, a risk-based suppliers’ evaluation module is proposed. Linguistic values are used to assess the ratings and weights for the risk based supplier selection factors. These linguistic ratings can be expressed in triangular fuzzy numbers. Then, a hierarchy MCDM model based on fuzzy-sets theory is proposed to deal with the supplier selection problems in the supply chain system. According to the concept of the fuzzy TOPSIS (Technique for Order Preference by Similarity to Ideal Solution), a closeness coefficient is defined to determine the ranking order of all suppliers by calculating the both fuzzy positive-ideal solution and fuzzy negative-ideal solution, simultaneously. Empirical data have been analysed and results obtained thereof, have been reported to exhibit application potential of the decision-support systems in appropriate situation

    Visualization of hydrogen injection in a scramjet engine by simultaneous PLIF imaging and laser holographic imaging

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    Flowfield characterization has been accomplished for several fuel injector configurations using simultaneous planar laser induced fluorescence (PLIF) and laser holographic imaging (LHI). The experiments were carried out in the GASL-NASA HYPULSE real gas expansion tube facility, a pulsed facility with steady test times of about 350 microsec. The tests were done at simulated Mach numbers 13.5 and 17. The focus of this paper is on the measurement technologies used and their application in a research facility. The HYPULSE facility, the models used for the experiments, and the setup for the LHI and PLIF measurements are described. Measurement challenges and solutions are discussed. Results are presented for experiments with several fuel injector configurations and several equivalence ratios
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