Journal of Light & Visual Environment
Online ISSN : 1349-8398
Print ISSN : 0387-8805
ISSN-L : 0387-8805
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Showing 1-12 articles out of 12 articles from the selected issue
Lighting Photo Albums
Foreword
Report
  • Masao Furusho, Makoto Bessho
    2017 Volume 40 Pages 7-9
    Published: March 10, 2017
    Released: March 30, 2017
    JOURNALS FREE ACCESS

    This year 2016, the Illuminating Engineering Institute of Japan (IEIJ) has been celebrated its 100th anniversary of foundation. The memorial events have been planned and organized by the 100th anniversary committee of IEIJ. The several kinds of events such as the international conference (LS15), the 100 years’ historical record of IEIJ, the memorial ceremony, the celebration party with the Emperor and Empress, the fund-raising activities for supporting these events, the publication for promoting public awareness and so on.

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Papers
  • Ken-ichiro Suehara, Ken-ichi Isoda, Hitoshi Mizutani, Atsushi Hashimot ...
    2017 Volume 40 Pages 10-19
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: June 17, 2016
    JOURNALS FREE ACCESS

    To eliminate the color appearance variation of the images acquired under the various lighting conditions, we have developed a simple four colored chart (Skin chart) for the color calibration of the human skin images based on the features of the human skin color. The color calibration with the Skin chart worked better than that with a standard color chart. A conventionally obtained photo-image of the pressure ulcer (PU) in medical facilities can be translated into a standard photo-image taken in the standard lighting. The present method is more convenient compared with the previously reported systems using the commercially available color charts. Accordingly, the method successfully identified the involved areas from the healthy skin areas by the color image. The newly developed method is a useful tool for the color image acquisition using conventional digital cameras for the electronic medical recording systems and for the medical consulting network by the information communication technologies (ICTs). The developed color calibration method enables simple, easy, rapid, and less expensive record for the shapes of PUs and the quantitative color distribution of the widely involved areas. Thus, this system is expected as an evaluation tool for the topical therapies for PUs in future.

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  • Shino Okuda, Katsunori Okajima
    2017 Volume 40 Pages 20-27
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: August 24, 2016
    JOURNALS FREE ACCESS

    This study aims to clarify which spectral component is critical for preferable appearance of the skin of the women’s faces in daily lives. We conducted a subjective experiment on the appearance of a woman’s face with make-up. We created spectral distributions by adding or cutting a specific wavelength on a flat spectral distribution with a wavelength programmable light source. We set up 53 kinds of lighting conditions with different spectral distributions in total. We measured the skin color of the face of the female model, and transformed measured chromaticity values into RGB values of a calibrated LC-display for generating the digital images of the lower half of the face. Twenty female participants observed the cheek illuminated by one of lights with different spectral distributions and evaluated the “naturalness”, “activity”, “sophistication”, “health”, “familiarity” and “preference” of the face. The results show that the lighting including the spectral component of 534 nm makes look the women’s skin worst, and the preference of women’s face can be explained with three aspects, naturalness, activity and sophistication.

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  • Keiichi Mochizuki, Kenji Sakurai, Yoshinori Shinohara, Akihiro Tagaya, ...
    2017 Volume 40 Pages 28-35
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: September 14, 2016
    JOURNALS FREE ACCESS

    We propose a light-emitting diode (LED) flat lighting panel that is capable of seamless connection by optimizing the shape of the optical elements, as well as the concentration of the scattering particles used in the diffuser material. The LED flat lighting panels that we develop can be connected to other panels while maintaining a uniformity of 90% throughout the entire surface. The results of subjective experiments reveal that the seams between the connected LED flat panels are virtually unnoticeable. We also discuss the optimal lighting designs for using the LED flat lighting panels as bracket lighting and ceiling lighting by measuring their primary optical characteristics. In particular, the unified glare rating of the seamless panel is 19.4, which corresponds to the minimum level of uncomfortable glare. Moreover, the seamless panel exhibits a luminous efficiency as high as 79.6 lm/W, which satisfies Energy Star requirements. These evaluations show that the LED flat panel is capable of providing comfortable space and lighting designs for architecture in an environmentally friendly manner.

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Translated Paper
  • Shigeo Kobayashi, Masahide Kakudate
    2017 Volume 40 Pages 36-45
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: June 17, 2016
    JOURNALS FREE ACCESS

    This research targeted a suburban area in Rikuzen-Takata of the Tohoku district in Japan where large numbers of temporary buildings have been built after the great earthquake 2011. The research aimed to install adequate light fixtures which guide people to higher ground and provide them with the safety and comfort in daily life. The lighting design was examined based on the knowledge of several field surveys and previous researches. Finally, a total of 179 lights, such as incandescent bulbs were attached. The questionnaire survey to residents was carried out before or after the lighting installation. As a result, it was confirmed that the recognition of entrances to evacuate or the evacuation directions which guide to higher ground had increased enough compared with the previous situation. It was also confirmed in the temporary shopping district or the construction office that surrounding visibility and safety had been improved by lighting. The lighting social experiment was conducted over September 2013 to about one month. Most light fixtures have been continuously maintained by residents even after the end of the experiment.

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Research Notes
  • Toshie Iwata, Yusuke Tsuyuki, Daisuke Ito, Kenta Tsuda
    2017 Volume 40 Pages 46-51
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: June 17, 2016
    JOURNALS FREE ACCESS

    The upward flux from the cities may cause sky glow. The purpose of our study is to calculate the upward flux from luminance distribution of night sky viewed from ground level on cloudy days. In this study the clouds’ heights and the reflectance of the clouds are used as well as luminance distribution of the night sky to calculate the upward flux. The reflectance of the cloud is presumed from the cloud type which is determined from the cloud model of Liou’s study referring to cloud heights and radiant temperature. An experiment is carried out using a scale model to verify the precision of the method. It is confirmed that upward flux can be almost precisely calculated by this method. The Tokyo metropolitan area is divided using grids (2.5 km×2.5 km) and the upward luminous flux of each area is calculated. A set of six measurement points is chosen which can measure the upward luminous flux from all light-emitting areas, and each measurement point must not have any obstacles in the viewing angle of the cloud infrared radiometer. The results show that 5 lm/m2 of upward luminous flux was emitted from the center of Tokyo. The distribution of the electricity wastage emitted to the sky was also illustrated.

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  • Francesco Leccese, Carlo Montagnani, Sergio Iaia, Michele Rocca, Giaco ...
    2017 Volume 40 Pages 52-65
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: June 29, 2016
    JOURNALS FREE ACCESS

    In hospital buildings, such as in other large and multi-purpose buildings, a wide variety of work environments can be distinguished, each of which characterized by specific visual tasks. In hospitals the visual tasks are often very demanding and consequently the lighting should be functional to ensure efficiency, safety, hygiene and well-being of medical and auxiliary staff, during the development of their activities. For this type of buildings the activity of in situ measurements is strongly recommended in order to evaluate the quality of lighting and also to perform a lighting risk assessment. In this paper an extensive lighting measurements campaign in a hospital is described. The hospital used as a case study is the “Felice Lotti” in Pontedera (Pisa district, Tuscany Region, Italy) where illuminance and luminance measurements have been carried out for different environments with different uses typically found in hospitals. The measurement results are described and discussed in detail, with particular reference to the compliance with the requirements imposed by the technical standards.

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  • Yoshinari Ishido
    2017 Volume 40 Pages 66-70
    Published: March 10, 2017
    Released: March 30, 2017
    [Advance publication] Released: July 13, 2016
    JOURNALS FREE ACCESS

    Nanoporous silica glass is found to be much available for light driven hydrogen production. However, the mechanisms of production enhancement have been merely understood. From the viewpoint of optics, we try to analyze theoretically the enhancement on converging a natural light into the nanopore of a transparent substrate within photochemical species using radiant transfer model. As a result, it is found that explosive growing the irradiated area of the inner surface on photochemical species in the nanoporous system brings a spectral merit. However, some numerical calculations of the form factor between the outer and inner surface of the system are needed for more precise inference on its priority of light convergence to alternative fabrics.

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Translated Paper
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