著者

藤井 健史 山田 悟史

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.88, no.811, pp.2636-2642, 2023-09-01 (Released:2023-09-01)

参考文献数

13

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In this study, a total of 28,800 random tree placement models were generated from combinations of 12 tree shapes and 8 stages of green coverage, assuming a site of 50m square. Then, using the generated model, a Monte Carlo simulation of green visibility calculation was performed to obtain an expected value of green visibility rate for each condition. In addition, the calculation results were expressed in figures and estimation formulas so that they can be easily referred to actual tree placement plans. These achievements have made it possible to plan tree placement based on the scientific index of green visibility.

著者

藤井 健史 山田 悟史

出版者

一般社団法人 日本建築学会

雑誌

日本建築学会技術報告集 (ISSN:13419463)

巻号頁・発行日

vol.26, no.63, pp.802-807, 2020-06-20 (Released:2020-06-20)

参考文献数

18

被引用文献数

1

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Using GPGPU, we developed a method to calculate the solid angle of landscape elements with an omnidirectional field of vision, via intersection detection. We confirmed that the processing speed was approximately 500 times faster than the processing speed achieved using a single CPU. Furthermore, the developed method was applied for the calculation of the omnidirectional green visibility of models with randomly arranged trees. Thus, the relationship between the shape and number of trees and the omnidirectional green visibility was analyzed statistically. These results can be considered as an index of the green visibility rate when planning the arrangement of trees.

著者

藤井 健史 寺口 絢子

出版者

立命館大学歴史都市防災研究所

雑誌

歴史都市防災論文集 (ISSN:18821766)

巻号頁・発行日

vol.14, pp.209-214, 2020-07

著者

山田 悟史 藤井 健史 宗本 晋作

出版者

日本建築学会

雑誌

日本建築学会計画系論文集 (ISSN:13404210)

巻号頁・発行日

vol.81, no.727, pp.2083-2093, 2016 (Released:2016-09-30)

参考文献数

29

被引用文献数

5 7

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In recent years, there have been a number of social initiatives related to improving the environment in city landscapes. Green space is becoming a tool to enhance the comfort of city space. "The Basic Plan for Green of Kyoto City" is one such example, where the ratio of visible green space is being used as a tool to improve the city environment. Many studies are being carried out to support this initiative and this study is one of them. The purpose of this study was to: 1) present a method to measure the location/angle specific ratio of green spaces in the omnidirectional visibility rate using a three-dimensional model of the target location, 2) create a perception deduction model based on Self-organizing Maps and 72 variables of visible green space in omnidirectional visibility rate, and 3) statistical verification of the accuracy of the perception deduction model. There are 72 categories of green space in the omnidirectional visibility rate. These categories are based on the location- and angle specific ratio of these spaces. Six of these categories were used for the location specific measurement, namely, "tall trees", "medium trees", "shrubs", " implantable ", "ground cover", and "others". Twelve angle specific measurements for every fifteen degrees were used and eight perception estimation parameters were selected. The perception estimation parameters included: “many or less", "satisfied or not satisfied", "pleasant", "serene", "covered (wrapped)", "close by or far", " surrounded by", "refreshing” and “widely spread". In this paper, we present results from the "ratio of visible green space in the omnidirectional visibility rate map”, the “self-organizing map" and the "perception estimation value map”. During the verification of the perception estimation model (the primary objective of this study), we compared the estimated perception values with the survey based observed values associated with a location of green space that was not included in the model creation. When we compared them statistically, we confirmed a significant correlation (n=32, p<0.05) between the estimated values and observed values (Pearson's correlation). We noted that the strength of the correlation was moderate but significant (correlation coefficient values around 0.6), with when we used the lower significance level (p<0.001). Taking into account effect size from psychological statistics, the average difference between the estimated and observed values of perception can be considered small for the parameters "many or less" "satisfied or not satisfied", "pleasant", "serene", "covered (wrapped)", "close by or far" and" surrounded by". However, the average difference was moderate for “Refreshing” and “Widely spread” and a significant difference between observed and estimated perception values was noted for these parameters in a paired t-test. Consequently, this perception deduction model is able to predict low and high values of “Refreshing” and “Widely spread", however, we need to be aware of the one degree difference, which happens to be the width of the confidence interval and may affect the estimated values.