4,781 research outputs found

    On the stability and structure of shock waves in interplanetary space

    Get PDF
    Structure of interplanetary shock waves formed by interaction of geomagnetic field and solar wind - earth bow shoc

    The lunar atmosphere Scientific report

    Get PDF
    Lunar atmosphere data and postulated theory of its structur

    An investigation of surface albedo variations during the recent sahel drought

    Get PDF
    Applications Technology Satellite 3 green sensor data were used to measure surface reflectance variations in the Sahara/Sahel during the recent drought period; 1967 to 1974. The magnitude of the seasonal reflectance change is shown to be as much as 80% for years of normal precipitation and less than 50% for drought years. Year to year comparisons during both wet and dry seasons reveal the existence of a surface reflectance cycle coincident with the drought intensity. The relationship between the green reflectance and solar albedo is examined and estimated to be about 0.6 times the reflectance change observed by the green channel

    The experimental determination of tyre model parameters

    Get PDF
    SUMMARY This report describes the analysis of a series of experiments on pneumatic tyres which were designed to test the various hypotheses: regarding the deformed shape of a tyre during the steering process. The experiments consisted of several separate tests first described in Ref. 1 and 2. a) The application of a point lateral force or a moment at one position on the tread band which is restrained at the centre of the wheel, and the measurement of the resulting lateral deflection of each point of the tyre perimeter. b) The application of a uniform force around the tyre perimeter on a hollow cylindrical former and applying a load at the centre of the wheel. c) Direct determination of tread band tension by cutting the tread band and bridging the cut by a dynamometer. d) Estimation of the bending modulus of the tread band by test on sections cut from the tread band. The analysis of the experiments is carried out by first transforming the test results into a Fourier series and determining the spectral content of the bending line with an harmonic analysis. Transfer functions of beam and string models are derived and applied to the test results. A method of considering a three parameter model is described

    The GeV-TeV Connection in Galactic gamma-ray sources

    Get PDF
    Recent observations with atmospheric Cherenkov telescope systems such as H.E.S.S. and MAGIC have revealed a large number of new sources of very-high-energy (VHE) gamma-rays from 100 GeV - 100 TeV, mostly concentrated along the Galactic plane. At lower energies (100 MeV - 10 GeV) the satellite-based instrument EGRET revealed a population of sources clustering along the Galactic Plane. Given their adjacent energy bands a systematic correlation study between the two source catalogues seems appropriate. Here, the populations of Galactic sources in both energy domains are characterised on observational as well as on phenomenological grounds. Surprisingly few common sources are found in terms of positional coincidence and spectral consistency. These common sources and their potential counterparts and emission mechanisms will be discussed in detail. In cases of detection only in one energy band, for the first time consistent upper limits in the other energy band have been derived. The EGRET upper limits are rather unconstraining due to the sensitivity mismatch to current VHE instruments. The VHE upper limits put strong constraints on simple power-law extrapolation of several of the EGRET spectra and thus strongly suggest cutoffs in the unexplored energy range from 10 GeV - 100 GeV. Physical reasons for the existence of cutoffs and for differences in the source population at GeV and TeV energies will be discussed. Finally, predictions will be derived for common GeV - TeV sources for the upcoming GLAST mission bridging for the first time the energy gap between current GeV and TeV instruments.Comment: (1) Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Stanford, USA (2) Stanford University, W.W. Hansen Experimental Physics Lab (HEPL) and KIPAC, Stanford, USA (3) ICREA & Institut de Ciencies de l'Espai (IEEC-CSIC) Campus UAB, Fac. de Ciencies, Barcelona, Spain. (4) School of Physics and Astronomy, University of Leeds, UK. Paper Submitted to Ap

    Japanese Investment in United States Securities: 1980-1985

    Get PDF
    This paper will deal with the topic of Japanese investment in United States securities during the years of 1980 - 1985. It is my contention that the vulnerable U.S. economic position created an opportunity for Japan to exercise political leverage over the U.S. to affect U.S. policy toward Japan. This paper will outline general and specific hypotheses, a discussion of the case and an explanation of possible methodology

    Hydrolytic and Photochemical Degradation of Organophosphorus Pesticides

    Get PDF
    To keep pace with demands for increasing food supplies to satisfy the expanding world population, modern agriculture has utilized the latest scientific and technological knowledge available. Increases in crop production through the use of growth regulators, fertilizers , herbicides, and insecticides have been little short of phenomenal, and drugs, feed additives, and higher-quality grain and forage have dramatically increased livestock production. But, as is usually the case, this progress has been accompanied by problems, one of the more serious being contamination of our environment by chemicals. Only in recent years have the full effects of these pollutants on the ecological balance of nature begun to be understood in all the intricacies and implications

    European Community Competition Law, Subsidiarity, and the National Courts

    Get PDF

    Comparing Probabilistic Models for Melodic Sequences

    Get PDF
    Modelling the real world complexity of music is a challenge for machine learning. We address the task of modeling melodic sequences from the same music genre. We perform a comparative analysis of two probabilistic models; a Dirichlet Variable Length Markov Model (Dirichlet-VMM) and a Time Convolutional Restricted Boltzmann Machine (TC-RBM). We show that the TC-RBM learns descriptive music features, such as underlying chords and typical melody transitions and dynamics. We assess the models for future prediction and compare their performance to a VMM, which is the current state of the art in melody generation. We show that both models perform significantly better than the VMM, with the Dirichlet-VMM marginally outperforming the TC-RBM. Finally, we evaluate the short order statistics of the models, using the Kullback-Leibler divergence between test sequences and model samples, and show that our proposed methods match the statistics of the music genre significantly better than the VMM.Comment: in Proceedings of the ECML-PKDD 2011. Lecture Notes in Computer Science, vol. 6913, pp. 289-304. Springer (2011
    • …
    corecore