Journal of Light & Visual Environment
Online ISSN : 1349-8398
Print ISSN : 0387-8805
ISSN-L : 0387-8805
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Volume 19, Issue 2
Displaying 1-8 of 8 articles from this issue
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Papers
  • Perception Under Road Lighting Conditions with Complex Surroundings
    Kohei NARISADA
    1995 Volume 19 Issue 2 Pages 2_5-2_14
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_5
    JOURNAL FREE ACCESS
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  • Development of a Photometer Having Variable Spectral Responsivity
    Tamaki YAJI, Ryuji TSUCHIYA, Fumio OHTANI, Yasuo NAKAGAWA
    1995 Volume 19 Issue 2 Pages 2_15-2_19
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_15
    JOURNAL FREE ACCESS
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    A photometer having variable spectral responsivity has been developed. The equipment is composed of a linear variable interference filter (LVIF), a MOS linear image sensor (CCD), driver/amplifier circuits, a 12-bits A/D converter and a note-type personal computer. The intrinsic relative spectral responsivity has been calibrated throughout the wavelength range from 400 to 700 nm by using the distribution temperature standard lamps. Then, it is possible to change its effective spectral responsivity as desired by weighting the output of each CCD element. In this study, the performance of the equipment as an illuminance meter, a simple spectroradiometer and a colorimeter has been evaluated by setting the relative spectral responsivity of the equipment to the spectral luminous efficiency, to a constant and to the matching functions, respectively. As a result, it is shown that the equipment has similar performance to a precise class of illuminance meter on the market. It is confirmed that the performance of the equipment almost meets the requirement for its use as a simple spectroradiometer and a colorimeter. Consequently, it is expected that this equipment can function as a mesopic photometer whose spectral responsivity varies with brightness.
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  • Change in Automobile Visibility at Dusk
    Kazumoto MORITA, Jin’ichi MASHIKO, Shin’ichiro ITOH, Takeo ...
    1995 Volume 19 Issue 2 Pages 2_20-2_26
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_20
    JOURNAL FREE ACCESS
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    Determinants of automobile visibility include the factors peculiar to the vehicle, such as type of lamps, as well as external factors, such as change in surrounding brightness. At dawn and dusk, even if the lighting conditions caused by the vehicle’s lamps remain the same, automobile visibility can be expected to change in accordance with the change in surrounding brightness. For this study, perception experiments by observers have been used to understand how visibility changes during twilight hours in the case of passenger cars and a motorcycle. In the experiments, the visibility of a passenger car with all lamps turned off is taken as the standard mean. The experiments show that, (in the case of an automobile with lamps turned on) the tendency of visibility to improve as the surroundings become darker can be quantitatively confirmed as a function of road surface luminance. Moreover, as a result of simulating perception judgments of observers by taking account of the two factors (a factor determined by surrounding brightness and one determined by automobile lights), it is possible to obtain analysis results that are quite similar to those recorded through actual evaluation.
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  • Numerical Simulation on Surface Movement Guidance and Control of Aircraft Automated by Airport Lights
    Yoshiro AOKI, Tetsuo TANIGUCHI, Takashi IRIKURA
    1995 Volume 19 Issue 2 Pages 2_27-2_32
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_27
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    This paper introduces a newly developed surface movement simulation program to simulate the movement of taxiing aircraft. The program determines automatically the shortest route for each plane, taking account of the delay time required when two or more aircraft are taxiing near each other. The following results are clarified by the use of the program:
    (1) Surface movement times simulated for the automated surface guidance system are not very different from those measured in the actual system. The automated surface guidance system is capable of traffic efficiency equal to that of actual system during daylight hours and with good visibility, if the method to partition taxiways into the block sections and the route selection method are good.
    (2) When traffic density is light, the majority of requirements to reduce the taxiing speed in the automated surface guidance system occur at the taxi-holding positions. However, aircraft are frequently required to reduce the taxiing speed even at the stop bar positions other than the taxi holding positions with increase of traffic density, thus increasing the overall number of decelerations. Therefore, highly effective stop bar lights will extend to all areas of airport surface, as traffic density increases.
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  • The Matching Network of the Inductively Coupled Discharge Lamps
    Masaki SHINOMIYA
    1995 Volume 19 Issue 2 Pages 2_33-2_39
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_33
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    Inductively coupled electrode-less discharge lamps have been developed as new light sources. To operate these lamps, matching networks are used for stabilizing the plasma. However, the design theory of the matching networks for these lamps has not been clearly known. The difficulty comes from the non-linearity of the plasma impedance. In this paper, the matching networks for the inductively coupled electrode-less discharge lamps are theoretically analyzed by means of an equivalent circuit model consisting of the two inductors connected in parallel and in series to the plasma resistance. First, the author took measurement of the input impedance of the electrode-less fluorescent lamp circuit, and confirmed the validity of the equivalent circuit model. Using this model, he analyzed the matching network, and found that an impedance-inverter circuit consists of the matching network and the coil is most preferable for starting and stabilizing the plasma. In this circuit, the plasma current lp is limited by the formula, /lp/<ne/B/, where n is the constant defined by the coil structure, e is electromotive force of the power source, and B is the parameter determined by the circuit. The author also calculated the circuit parameters in the case of a 5-ladder circuit.
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  • Illuminance Calculation in a Room Containing Fixtures
    Naotaka IKEMOTO, Minoru ISOMURA
    1995 Volume 19 Issue 2 Pages 2_40-2_47
    Published: 1995
    Released on J-STAGE: January 12, 2011
    DOIhttps://doi.org/10.2150/jlve.19.2_40
    JOURNAL FREE ACCESS
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    This paper describes a new approximate calculation of interreflection in a room containing fixtures. In the conventional calculation for interior lighting which is based on luminous flux transfer, the number of calculated form factors and hence the computation time increases with the number of surface elements. For this evaluation, the illuminance of each surface in the room calculated vary in fixture type, fixture height, and fixture reflectance. We present results that the approximate values have strikingly good agreements with the exact values for the average illuminance and illuminance distribution of all surfaces, and the computation time is much shorter.
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