Shimizu N.,Yamaguchi University |
Masunari T.,Furuno Electrical Co. |
Iwasaki T.,Kokusai Kogyo Co.
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics | Year: 2012
Monitoring rock deformations is important to assessing the stability of rock structures, i.e., slopes, tunnels, dams, foundations, etc., in order to confirm the validity of the design during/after construction and to assist in answering specific questions on a project. A new displacement monitoring system using GPS has been developed by the authors and their colleagues. The system can measure three-dimensional displacements automatically with mm accuracy, and it is now being widely used in various Rock and Geotechnical Engineering projects. In this paper, the technology of the GPS displacement monitoring for the precise measurements of rock movements is summarized, and its practical applications are described. © 2012 Taylor & Francis Group, London.
Sato T.,Kokusai Kogyo Co.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2010
Three case applications for forest resource assessment using airborne laser scanner (LiDAR) will be introduced. The first case is "assessment of high density forest area". The area where forest maintenance is necessary is extracted using colour composite of three layers developed from laser point group; (1) attained distance from DSM into forest (2) tree height (3) reflection intensity. The second case is "applied counting method for the number of trees". The method is based on local maximum filtering but improved to be able to calculate the distribution of multi-storied forest by analyzing laser point group. This method is also able to count the number of lower storied trees by considering the area. The third case is "extracting hazard area facing fallen trees". The risk of fallen trees into conservation area (houses and roads) is evaluated by calculating the location and height of trees using local maximum filter and buffering the tree height from the tree location.
Nakasuji A.,Kokusai Kogyo Co.
Journal of Mountain Science | Year: 2011
This paper reports a method to make hazard maps of sediment disasters resulting from an earthquake and following heavy rainfall for the entire region of Gunma prefecture, Japan. Firstly, we identified the slopes in the study area, which are susceptible to large-scale landslides and land failures during an earthquake with a magnitude of seven on the Richter scale. To analyze the sheer volume of the data, we employed a statistical method to evaluate the susceptibility, mainly considering geomorphologic conditions. Secondly, we extracted mudflow and slope failure susceptible areas and potential flooding zones resulting from a damming at a river triggered by the earthquake and heavy rainfall, and we identified the settlements which would be isolated by the road disruption caused by the sediment disasters. As the result, 359 settlements were classified as potential isolation areas. Combining the above-mentioned susceptibility maps, we obtained two types of sediment disaster hazard maps of the study area, depicting the potential hazards which would occur during the earthquake and the disasters which would be caused by heavy rainfall following the quake, respectively. These hazard maps and the disaster information would be useful for the regional disaster prevention planning and countermeasures in the future. © 2011 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg.
Ota M.,Kokusai Kogyo Co. |
Plews R.,Plews Consulting
Cartography and Geographic Information Science | Year: 2015
This paper presents the development of an "all-in-one" software tool, called "gittok" [pronounced: jee-tock, itk] that assists both higher education students and industry professionals in learning about Geospatial Information Technology (GIT) based on the concepts of geospatial standards. While there are a number of popular and advanced open source Geographic Information Science (GIS) systems and tools, the software designed in this research is not a GIS, but an education assistance tool that helps to teach the basic concepts of GIT. Gittok was designed around the basic concept of using geospatial standards to help with learning the knowledge areas of GIT. Gittok allows students to acquire and edit geospatial data directly in compliance with an application schema. Users of the gittok software can gain an overview of GIT and directly experience, through "hands-on" operation, spatial analysis, XML data exchange, geo-library management and map design. Therefore, the authors hope that gittok will become a popular and useful tool for GIT education. © 2015 Cartography and Geographic Information Society.
Matsuoka R.,Kokusai Kogyo Co. |
Matsuoka R.,Tokai University
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2014
Circular targets are often utilized in photogrammetry and a circle on a plane is projected as an ellipse onto an oblique image. This paper reports an experiment conducted to investigate whether the measurement accuracy of the center location of an ellipse on a digital image oscillates as its dimension increases. The experiment was executed by the Monte Carlo simulation using 1024 synthesized images of which the centers were randomly distributed in one pixel for each ellipse. We investigated four typical measurement methods: intensity-weighted centroid method, non-iterative ellipse fitting, iterative ellipse fitting with the star operator, and least-squares matching. Three flattenings 0.00, 0.25, 0.50, and three rotation angles 0.0°, 22.5°, 45.0° were investigated in the experiment. The experiment results clearly show that the measurement accuracy by all the investigated methods would oscillate as the dimension of an ellipse increases. The measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting would oscillate smoothly, while that by the least-squares matching would oscillate considerably roughly. It would be impossible to determine the cycle of the oscillation except the measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting when the rotation angle of an ellipse is 0.0° and 45.0°. The experiment results indicate that the flattening and the rotation angle of an ellipse would affect the cycle of the oscillation as well.