En-Mi Lim

Thermal Comfort and Outdoor Activity in Japanese Urban Public Places

Subjective thermal comfort and outdoor activity in a park and a square in a satellite city northeast of Tokyo were investigated through structured interviews, observations, and comprehensive micrometeorological measurements. Results showed that the park was on an average 1.1°C cooler than the square. The relatively warmer thermal conditions in the square in comparison to the park resulted in a heat load of greater intensity for humans in the square. In general, there was a low relation between the thermal environment and the use of the two places in terms of total attendance. However, the use of the park was influenced more by the thermal conditions than by the use of the square, which can mainly be attributed to the different functions of the two places. Finally, examples of the differences between the use of the sun, the attitudes toward it, and outdoor exposure in Japan and Sweden are highlighted and discussed.

Visualization of landscape by VRML system

Virtual reality modeling language (VRML) is a high performance language for three-dimensional (3-D) visualization on the World Wide Web (WWW). Three-dimensional information can be easily transferred through the Internet by this technology. In this study, we made a landscape visualization system that enables virtual experience in a planned landscape by using VRML and the applicability of the system to the landscape design was shown. To perform real-time rendering of landscape, a tree was expressed by using two textured planes instead of thousands of polygons. Trees were placed automatically on a textured terrain based on the plant database by the system developed in this study. With the system, we made models of real gardens based on measured data and walk-through simulations in the gardens were tested. The system showed good performance and it also indicated the potential of VRML systems. The information on the virtual landscape can be placed on WWW. This method can be utilized both for the design of and for the public discussion on landscape planning.

Three-dimensional visualization forest of landscapes by VRML

Abstract Computer technology has been used to develop three-dimensional (3D) forest landscape visualization systems that include the function of three-dimensional digital plant modeling. While the earlier systems accurately simulated forest landscapes, they lacked sufficient speed and could not adequately perform walk-through simulations. The objective of this study is to describe the forest landscape visualization procedure capable of walk-through simulations and its application. We developed a forest landscape visualization system using virtual reality modeling language (VRML). This visualization system works with data of forest stands rather than individual trees. To confirm the feasibility of the system, we visualized an actual forest landscape with thousands to tens of thousands of trees. We also simulated a variety of forest landscapes and showed how this system can be used to simulate the changes of forest landscapes that occur as a result of natural processes or man-made disturbances such as planting, thinning, and harvesting. This visualization system was capable of walk-through simulation and the three-dimensional images rendered by the system enabled us to effectively visualize the forest landscape resources. The visualization by computer graphics also made it possible to confirm the accuracy of forest data.

The Study of Landscape Visualization Method by VRML and Plant Model Database

VRML (Virtual Reality Modeling Language) は, インターネット上での景観可視化に大きな可能性を持つ。本研究では小石川後楽園を対象として, 数千本の樹木を有する本格的な景観の可視化にVRMLを実用的に用いることができるかを検討した。そのため, 2次元植物形状データベースを作成・整備した。また, 高性能の景観設計システムであるAMAPで作成した景観画像との比較を行った。その結果, 本格的な景観設計にVRMLが使用可能であること, 高品質の植物を含む景観画像作成が可能であることを明らかにした。

Landscape Visualization on Google Earth

Three-dimensional landscape information can be easily transferred through the Internet with Google Earth. In this study, we developed a landscape visualization system that enables simulation of planned landscape on Google Earth and the applicability of the system to the landscape design was shown. The visualization system generates KML (Keyhole Markup Language) and KML file is visualized on Google Earth. To make the data small, a tree was expressed by using textured planes instead of thousands of polygons. Trees were placed automatically on a terrain based on the measured data by the system developed in this study. With the system, we made models of real gardens based on measured data and walk-through simulations were tested. The system showed good performance and it also indicated the potential of the systems.

Fitting the Truncated Bivariate Normal Distribution to the Relationship between Diameter and Length of Current-Year Shoots in Betula Platyphylla in Hokkaido, Northern Japan

We fitted a truncated bivariate normal distribution to the relationship between diameter and length of current-year shoots in Betula platyphylla saplings, and examined the effects of light intensity at the branch tip and branch height on the relationship. We measured shoot length, diameter at the shoot base, light intensity at the branch tip, and branch height for all shoots on 49 sampled saplings. The relationship between shoot diameter and shoot length was almost linear with a positive intercept. The truncated bivariate normal distribution could describe the relationship of shoot diameter and shoot length none of which was an independent variable. The result of model fitting revealed that, given a shoot length, shoot diameter was larger for shoots that were located in higher positions in crowns and captured more light.

A Visualization System for Urban Planning and Design

In this study, we developed a landscape visualization system, which we named town-maker, to generate the virtual reality image of urban landscape by using virtual reality modeling language (VRML) and plant modeling techniques. In order to test the feasibility of the landscape visualization system, we applied the system to a park with water space surrounded by large amount of green. We also simulated the landscape of a park with buildings by town-maker. The results showed that the virtual reality (VR) image by the system helped the public understanding of the concept of the urban planning.

Visualization of Greenhouse Environment by VRML

Abstract In this study, we developed a greenhouse visualization system by using VRML (Virtual Reality Modeling Language) that is a high performance language for 3-D visualization on WWW (World Wide Web). We developed a converter from designed parameters of a greenhouse to VRML format. Plant grown in a greenhouse can be chosen as one of parameters. Plant was visualized with 2 textured planes. We also made a database of two-dimensional plant images of several growth stages from 3-D plant shape generated by AMAP (a plant modeling system that produces very precise 3-D plant shape). With the developed system, greenhouses were visualized for the validation of the system. By using the system, walk thorough simulation in the greenhouses was possible in spite of the huge number of plant and building data. In conclusion, the system developed in this study can produce a very high quality images and will be used for design and visualization of greenhouses with very low cost.