The Journal of the Society for Art and Science
Online ISSN : 1347-2267
ISSN-L : 1347-2267
Volume 14, Issue 3
Displaying 1-5 of 5 articles from this issue
Papers
  • Katsutsugu Matsuyama, Kouichi Konno
    Article type: research-article
    2015Volume 14Issue 3 Pages 46-56
    Published: June 15, 2015
    Released on J-STAGE: April 19, 2023
    JOURNAL FREE ACCESS
    Supplementary material
    By focusing on the properties used to measure map projections and utilizing them to manipulate map projection parameters, we have developed a new interface for manipulating such map projections. With our interface, a user can create his or her own map projections by manipulating the weight of each property via sliders. Specifically, we employ equidistancy, equiareality, and conformality as property elements and allow the user to balance these property elements according to their perceived levels of importance. Additionally, along with this interface, we also have developed a technique for reducing the number of projection parameters by assuming that latitude lines are horizontal and that longitude widths are identical in each latitude, which improves execution speed. Furthermore, as an additional interface, we have implemented a method for creating interrupted maps. This allows users to make interruptions on a map easily by clicking the interruption panel. Our system also provides a new manipulation method with which the user can traverse a number of existing cylindrical projections, such as those created with the Mercator and Lambert cylindrical projection methods.
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  • Shun Sasaki, Katsutsugu Matsuyama, Kouichi Konno, Yoshimasa Tokuyama
    Article type: research-article
    2015Volume 14Issue 3 Pages 57-65
    Published: June 15, 2015
    Released on J-STAGE: April 19, 2023
    JOURNAL FREE ACCESS
    The laminating direction is important when we output an object measured by a system that can perform multi-directional mass simultaneous measurement by using a 3D printer. This is because the original edge shapes of output model may not be reproduced depending on laminating directions. Some methods have been proposed to evaluate reproducibility of edge shapes according to the direction and area of polygons, but they do not reproduce edge shapes but the whole model shape, so the edge shapes might be lost. In this study, according to the polygon models generated from measured points, we examine a method to evaluate the best posture so as to maintain the edge shapes of the original lamination model generated by the laminating method. We use relic models like flakes of chipped stone tools measured by the multi-directional mass simultaneous measurement system. Our method extracts the boundary edges on stripped surfaces from a polygon model. By comparing the extracted edge shapes to those generated by the laminating method, both shapes are evaluated. We have applied our method to some models and confirmed the effectivity of the method.
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  • Naoki Mita, Youngha Chang, Nobuhiko Mukai
    Article type: research-article
    2015Volume 14Issue 3 Pages 66-72
    Published: June 15, 2015
    Released on J-STAGE: April 19, 2023
    JOURNAL FREE ACCESS
    Supplementary material
    This paper reports a particle-based 3D simulation method of bubble rupture by considering the high ratio of the water density to the air density. We analyze the behavior of water and air as incompressible and compressible fluid, respectively, and express that a hole appears on the film of the bubble by the inner pressure. The film has a constant thickness, and surface tension operates between the film particles. Finally, we extract the fluid surface by using Marching Cubes, and render the surface by ray-tracing method. As a result of the simulation, we could confirm that a hole appears on the film of a bubble by the pressure difference between inner pressure and surface tension for a dome-shaped bubble on the water, and the hole expands having circle shape, and finally the water surface rises after the bubble ruptures. Furthermore, we have confirmed that the bubble behavior in the simulation is similar to the real one by comparing the simulation result and a video of the real one.
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  • Yuta KIMURA, Keimei KAINO, Toshiaki OKUMURA
    Article type: research-article
    2015Volume 14Issue 3 Pages 73-82
    Published: June 15, 2015
    Released on J-STAGE: April 19, 2023
    JOURNAL FREE ACCESS
    Supplementary material
    Regular polyhedron is regarded as an approximate figure of a sphere. Apple-peel fold-out (AF) nets of regular polyhedra have symmetric S-shaped figures and the net of a sphere a symmetric S-shaped spiral half of which consist of Archimedes' spiral and the lituus. There are six regular polytopes in the four-dimensional (4-D) space. AF nets of regular polytopes, regular 4-cube, 16-cell are obtained by using their axonometric projection diagrams. From this fact, two types of AF nets of 24-cell are shown to consist of 3-D spirals on both ends and central nets of S-shaped figure on a 2-D plane derived from their axonometric projection diagrams. These AF nets will give us a good algorithm to obtain AF nets of 120-cell and 600-cell.
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  • Shouta SUGANO, Tsukasa KIKUCHI
    Article type: research-article
    2015Volume 14Issue 3 Pages 83-90
    Published: June 15, 2015
    Released on J-STAGE: April 19, 2023
    JOURNAL FREE ACCESS
    This paper proposes a method for visually simulating snow spray caused by a snow avalanche. In this method, a polygon model is created of a mountain slope, then the snow particles that express snow clumps from the source of the avalanche are made to fall. The collision between the snow particles and the mountain slope is detected, then a velocity field of the expansion of snow spray is created based on a Navier-Stokes equation. The density of the snow spray that moves along this velocity field is subjected to volume rendering based on adaptive ray marching through the volume photon mapping method. This is used to visually simulate snow spray from a snow avalanche. This method can also express differences in snow spray resulting from differences in such things as the gradients of the mountain slope.
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