214 research outputs found

    The Japanese Treaty Ports 1868-1899: A Study of the Foreign Settlements.

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    The opening of Japan to foreign residence brought not only the same system of treaty ports and foreign settlements as had developed in China to solve the problem of the meeting of two very different cultures, but also led to the same people who had known the system in China operating it or living under it in Japan. The events of l859-l869 gave foreigners fixed ideas about the Japanese which subsequent changes could do little to alter. The foreign settlers quickly abandoned any ideas they may have had about making close contact with the Japanese. They preferred to recreate as near as possible the life they had lived in Europe or America, The main prop of this was extraterritoriality, which shielded them from Japanese laws. It was not a very efficient system and increasingly it worked against foreigners' own interests. Yet they demanded its continued existence, although the Japanese had made it clear by 1880 that they wished to see a complete end to it, and by 1886 the foreign powers were ready to agree to this. Extraterritoriality bedevilled foreign attempts to run their own municipal affairs, and except at Kobe, all such attempts proved failures. It also led to a loss of interest in the expansion of trade, for the Japanese made it clear that the price for this was the end of extraterritoriality. The foreign-language press was, apart from trade, the one major foreign contributor to Japan's modernisation, but it provided a poor service to foreign settlers. It was far too dependent on its subscribers ever to be really independent. The treaty ports themselves came to an end in 1899, but the foreign settlement ethos lingered on until the 1923 earthquake and the second world war finally killed it

    Underwater Optical Imaging for Automotive Wading

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    n underwater imaging system was investigated for automotive use in highly scattered underwater environments. The purpose of the system is the driver&rsquo s information about hidden obstacles, such as stones, driftwood, open sewer hatches. A comparison of various underwater vision methods was presented by the way they are implemented, the range reached, and the cost of implementation. It has been experimentally shown that a conventional active system can provide a maximum visibility range of up to three light attenuation lengths. In most practical cases of turbid waters during floods, this corresponds to distances of about 1 meter. From the presented analysis it follows that advanced extended range imaging methods allow increasing of the visibility range up to 2 meters. Document type: Articl

    Experimental evaluation of 79 and 300 ghz radar performance in fire environments<sup>†</sup>

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    This paper presents an experimental study of the propagation of mm-wave/low-THz signals in the frequency ranges of 79 and 300 GHz through fire. Radar performance was investigated in various real scenarios, including fire with strong flame, dense smoke and water vapour. A stereo video camera and a LIDAR were used as a comparison with other common types of sensors. The ability of radars to enable the visibility of objects in fire environments was proven. In all scenarios, the radar signal attenuation was measured, and in the case of steam was compared with theoretical calculations. The analysis of the experimental results allows us to conclude that there are good prospects for millimetre wave and Low Terahertz radar in the field of firefighting imaging equipment.</p

    Recognition of objects in orbit and their intentions with space‐borne sub‐THz Inverse Synthetic Aperture Radar

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    An important aspect of Space Situational Awareness is to estimate the intent of objects in space. This paper discusses how discriminating features can be obtained from Inverse Synthetic Aperture Radar images of such objects and how these discriminators can be used to recognise the objects or to estimate their intent. If the object is, for example, a satellite of a known type, the scheme proposed is able to recognise it. The ability of the scheme to detect damage to the object is also discussed. The focus is on imagery obtained in the sub-terahertz band (typically 300 GHz) because of the greater imaging capability given by the diffuse scattering which is observed at these frequencies. The paper also discusses the importance of being able to use images obtained by electromagnetic simulation to be able to train the subsystem which recognises features of the objects and describes a practical scheme for creating these simulations for large objects at these very short wavelengths

    High-Resolution Automotive Imaging Using MIMO Radar and Doppler Beam Sharpening

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    A highly detailed sensing of a vehicle's surrounding environment is a key requirement for the advancement of autonomous driving technology. While conventional automotive radar sensors remain robust under challenging weather conditions, poor cross-range resolution and high sidelobe levels present significant challenges. In this article, we propose an approach that combines multiple-input multiple-output (MIMO) beamforming with Doppler beam sharpening. We demonstrate a significant improvement in terms of cross-range resolution and, importantly, nearly 20-dB sidelobe suppression compared to conventional MIMO processing. This approach is investigated in detail and validated through theoretical analysis, simulation, and experiment using data recorded on a moving vehicle. We demonstrate performance that is comparable to a high-resolution mechanically scanned radar using a commercially available MIMO sensor.</p

    MIMO array for short-range, high-resolution automotive sensing

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    The anomalous accretion disk of the Cataclysmic Variable RW Sextantis

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    Synthetic spectra covering the wavelength range 900\AA~to 3000\AA~provide an accurate fit, established by a χν2{\chi}_{\nu}^2 analysis, to a combined observed spectrum of RW Sextantis. Two separately calibrated distances to the system establish the synthetic spectrum comparison on an absolute flux basis but with two alternative scaling factors, requiring alternative values of M˙\dot{M} for final models. Based on comparisons for a range of M˙\dot{M} values, the observed spectrum does not follow the standard model. Rather than the exponent 0.25 in the expression for the radial temperature profile, a value close to 0.125 produces a synthetic spectrum with an accurate fit to the combined spectrum. A study of time-series FUSEFUSE spectra shows that a proposed warped or tilted disk is not supported by the data; an alternative proposal is that an observed non-axisymmetric wind results from an interaction with the mass transfer stream debris.Comment: 56 pages, 15 figures, 11 tables. Accepted for The Astrophysical Journa
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