Papers by Nozomu Yoshizawa
Nihon kenchiku gakkai kankyokei ronbunshu, Aug 1, 2023
The aim of the present study is to clarify an evaluation structure for privacy that takes both vi... more The aim of the present study is to clarify an evaluation structure for privacy that takes both visual and auditory senses into account. First, the perceptions of visual privacy that is the feeling of being watched regardless of whether or not someone is looking at you, were examined, followed by a similar examination of auditory privacy, to further clarify the evaluation structure of privacy perceptions that take both visual and auditory privacy into account. The final goal is to obtain insight into a broader definition of privacy that can be applied to combined visual and auditory privacy.
Visibility is one of the fundamental factors for explaining the lighting environment, and various... more Visibility is one of the fundamental factors for explaining the lighting environment, and various quantitative indexes for these have been made in such a manner that directly finds the formulae that best match the numerous subjective evaluations. Recently neurophysiology-based models have been paid attention as the complementary or alternative methods to these conventional indexes. In this paper we will introduce the normalization and gain control models, which are generally accepted theories in the visual information processing, to estimate the visibility, and verify the validity of this algorithm by comparing with the subjective evaluation in the experimental room. The result showed that the algorithm in this research could estimate the visibility of the simple objects in the experimental space with a pseudo window with great accuracy, however, it is desirable and necessary to publicly discuss various algorithms and clarify their reliability based on the verification results under various situations.
Simple daylighting metrics is also necessary for the BIM design of residential houses. Prior to t... more Simple daylighting metrics is also necessary for the BIM design of residential houses. Prior to the establishment of annual daylighting metrics for residential houses in Japan, we investigated the indoor daylight environment in the houses on three blocks in Passive Town Kurobe. Firstly, several parameters and the settings of physical property values in the simulation were adjusted so that the percentage errors of the simulated average luminance on the interior surfaces in each house were less than 10%. Secondly, the annual daylighting simulation was conducted considering the actual operation of shading devices. Using the simulation results by referring to DA and sDA, we propose verDA (Vertical Daylight Autonomy) and versDA (Vertical Spatial Daylight Autonomy) as new daylighting metrics for residential houses in Japan. These metrics are calculated from the vertical eye illuminance, which is more relevant to brightness perception and human health.
Summaries of technical papers of Annual Meeting Architectural Institute of Japan. D-1, Environmental engineering I, Room acoustics and acoustic environment noise and solidborne sound environmental vibration light and color water supply and drainage water environment urban installation and environ..., Jul 30, 2003
The purpose of this paper is to clarify the evaluation structure of the preference for the visibi... more The purpose of this paper is to clarify the evaluation structure of the preference for the visibility of paintings, taking into account the characteristics of paintings with low reflectance. Although illuminance is used in the standards for museum lighting (CIE 157:2004), it is desirable to design lighting that also considers luminance from the viewpoint of perceived brightness. Therefore, we conducted the subjective experiment of oil paintings in which luminance ratio was set as an experimental variable and examined the evaluation structure of paintings with low reflectance. As a result, it was found that the evaluation of black details affects the preference for the visibility of paintings with low reflectance. However, the path diagram of the evaluation structure applied to each painting was different, indicating that it is difficult to represent the characteristics of a painting only by the mean reflectance.
Architects and users frequently use window coverings, such as frosted glasses, shoji screens, and... more Architects and users frequently use window coverings, such as frosted glasses, shoji screens, and lace curtains to create high quality of light. This kind of light is sometimes called “soft light”, and most people feel that it is required in residential spaces. However, the term “soft light” is somewhat vague, and we do not accurately understand what is the “soft light” and how we can create it. The aim of this research is to derive a physical indicator of "ambiguity of brightness-darkness boundary”, which is one of factors for judging the softness of light. We conducted a subjective experiment with 53 evaluation items including the “ambiguity of brightness-darkness boundary” in various actual daylighting spaces. It was found that "ambiguity of brightness-darkness boundary", was not highly evaluated when the average value of the luminance change rate on the wall is high.
IOP conference series, Nov 1, 2022
This study aims to verify the relationship between the spatial brightness evaluation and average ... more This study aims to verify the relationship between the spatial brightness evaluation and average luminance on a moving gaze point tracking by targeting offices with different luminance distributions. Subjects wearing eye-tracking devices evaluate the spatial brightness of the various light environments displayed on a large screen display. In the results, the tendency for gazing at the window is found to be high as compared to the other parts. The average luminance is calculated by integrating the time on the path of the moving gaze point. Furthermore, we analyse the relationship between the average luminance of each part of the light environment on the display and the brightness evaluation value. The average luminance considering the movement of the gaze point at the time of brightness evaluation has higher explanatory power,0.305, for the spatial brightness than the average luminance,0.259, in the entire visual field area. In contrast, the explanatory power of brightness evaluation was not improved drastically, even considering the gazing time and luminance. In future, the relationship between the evaluation of the spatial brightness and the gaze point/gaze time can be analysed by considering the absolute value of the luminance of the window surface and the luminance ratio with the surroundings.
IOP conference series, Nov 1, 2022
The direction, density, and diffusivity of light are important indicators of spatial characterist... more The direction, density, and diffusivity of light are important indicators of spatial characteristics in describing a three-dimensional light environment. Mury presented a method for describing, measuring, and visualizing the structure of light fields using spherical harmonics in terms of changes in the density and direction of light in three-dimensional space. We extended this study by using higher-order spherical harmonics, which would represent more diverse characteristics of the light environment. We also quantitatively described the light environment as numerical values and investigated the correspondence between these numerical values and human perceptual quantities. As a result, we confirmed that there is a certain degree of correspondence between the “complexity” quantified by the spherical harmonic and the “complexity” perceived by people when observing real space.
Spaciousness is an important quality of space which is affected by both the volume of space and t... more Spaciousness is an important quality of space which is affected by both the volume of space and the lighting environment. This study’s aim is to create the calculation model to quantify the effect of lighting environment on spaciousness. 3D luminance mapping, which is the combined data of luminance of surface and its distance to the observer, is used for the analysis of lighting environment, because we hypothesized that the three-dimensional localization of light affects the spaciousness. From the result of a subjective experiment to evaluate spaciousness with different lighting environment, it is revealed that spaciousness can be quantified from average luminance and “Dark-part-reduced visible volume” which is the reduced visible volume according to the distribution of dark pixels in the 3D luminance mapping. We also compared average illuminance of whole image and of ceiling, walls, floor, and concluded that the whole average illuminance best describes the effect.
Building and Environment, Sep 1, 2023
IOP conference series, Nov 1, 2022
The purpose of this study is to verify whether the spatial brightness of the real space can be re... more The purpose of this study is to verify whether the spatial brightness of the real space can be reproduced using the high-luminance large screen display. Firstly, we conducted the subjective experiment in the real space. Next, the linear scaling images to present on the highluminance large screen display were made from luminance and chromaticity data measured in the real space. The maximum value presentable by the display was 1,200cd/m², therefore, luminance above 1,200cd/m² were blown out. Then, the subjective experiment was conducted using those images displayed on the large screen display. The spatial brightness was memorized and answered by adjusting the luminance inside the reference space, called "adjustment box", so that the brightness in the box became the same as the one in the real space. From comparing the logarithmic values of the brightness evaluation of the real space and the one of the linear scaling images on the display, we found that the spatial brightness evaluation on the display roughly matched to the one of the real space. It was also suggested that there is a possibility that the effects of windows on the spatial brightness evaluation may be different between the real space and the two-dimensional display.
Nihon kenchiku gakkai kankyokei ronbunshu, 2007
Nihon kenchiku gakkai kankyokei ronbunshu, 2010
This is a study on identifying three indicators to evaluate the following senses of physical oppr... more This is a study on identifying three indicators to evaluate the following senses of physical oppression and of openness in urban spaces�configuration factors, solid angles, and space quantity. These senses of physical oppression and openness were evaluated by residents and students of architecture for nine designated streets and were evaluated by residents for the streets fronting their homes in the Sangenjaya area of Tokyo�s Setagaya ward. The results show that first, there is some variation in evaluating the two senses of physical oppression and openness between the two evaluated groups of residents and students of architecture; however, the results of the correlations show value in the indicators used for both residents and students of architecture. Second, these three indicators show high correlations for the nine designated streets but show weak correlations for the streets fronting residents� homes due to residents� subjective impressions. Therefore, these three indicators are valid for evaluating those senses of physical oppression and openness when objectively considering the senses of physical oppression and of openness.
Nihon kenchiku gakkai kankyokei ronbunshu, 2019
Lighting Research & Technology, Jan 21, 2023
This paper proposes a new method to depict the light field based on the volume photon mapping alg... more This paper proposes a new method to depict the light field based on the volume photon mapping algorithm. In the context of the light field simulation, a participating medium serves to deposit the photons, but does not disturb their propagation. The photons are therefore neither scattered nor absorbed in order to preserve their energy and trajectory within the environment, thus providing an unbiased luminance distribution. A visualisation of the photon distribution enables an intuitive interpretation of the light propagation that helps designers to understand the basic light field in the space. In addition to visualisation, the magnitude of the simulated physical light field can be numerically evaluated from the volume photon map distribution using, for example, cubic and scalar illuminance. This can further inform the designer on the light density distribution in the space, since the latter directly correlates with the density of the photons, and therefore the scalar illuminance. The accuracy of the proposed method was ascertained by comparing it with the original RADIANCE. Furthermore, its advantage in visualisation was demonstrated using a complex case study involving strong indirect lighting, reinforced by a comparison of the simulation and measurement in the actual space. In addition, photon mapping was found to evaluate illuminance in multiple grid points much faster than RADIANCE Classic, notably due to the complex ambient lighting from specular reflections. The implementation of the specialised volume photon mapping software is now part of the RADIANCE software and is available as a lighting research tool for the community.
IOP conference series, Nov 1, 2022
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Papers by Nozomu Yoshizawa