Masahiko Nagai

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To represent 3-D space in detail, it is necessary to acquire 3-D shapes and textures simultaneously and efficiently through the use of precise trajectories of sensors. However, there is no reliable, quick, cheap, and handy method for acquiring accurate high-resolution 3-D data on objects in outdoor and moving environments. In this paper, we propose a(More)
Three dimension data are in great demand for the various applications such as 3D GIS, navigation, digital archive, simulation, computer games, and so on. In order to represent space in details, it is indispensable to acquire 3D shape and texture together. However, there still lacks a reliable, quick, and handy method of acquiring three dimension data at(More)
Savannakhet Province, Lao People’s Democratic Republic (PDR), is a small area that is connected to Thailand, other areas of Lao PDR, and Vietnam via road No. 9. This province has been increasingly affected by carbon dioxide (CO2) emitted from the transport corridors that have been developed across the region. To determine the effect of the CO2 increases(More)
Mapping of volcanic activities or events during eruptions such as lava flow, pyroclastic flow, mudflow and etc. at real time basis is very important to monitor and predict movement of these events, and prevent calamity. These events are usually dynamic and occur in short time duration. In this study, a real time volcanic activity mapping system, using(More) 0924-2716/ 2014 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS) Published by Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +66 86 6229272. E-mail addresses: (K. Teeravech), (M. Nagai), (K. Honda),(More)
In the case of natural hazards the spatial extent of the disaster area is usually large. It is often difficult to conduct search and rescue operations from the ground. Such operations are often hindered due to the inaccessibility to the locality due to the damaged infrastructures. But it is often crucial that the victims are identified and rescued as soon(More)
The retrieval of nutrient concentration in sugarcane through hyperspectral remote sensing is widely known to be affected by canopy architecture. The goal of this research was to develop an estimation model that could explain the nitrogen variations in sugarcane with combined cultivars. Reflectance spectra were measured over the sugarcane canopy using a(More)
Urban expansion is considered as one of the most important problems in several developing countries. Bangkok Metropolitan Region (BMR) is the urbanized and agglomerated area of Bangkok Metropolis (BM) and its vicinity, which confronts the expansion problem from the center of the city. Landsat images of 1988, 1993, 1998, 2003, 2008, and 2011 were used to(More)
Tree parameter determinations using airborne Light Detection and Ranging (LiDAR) have been conducted in many forest types, including coniferous, boreal, and deciduous. However, there are only a few scientific articles discussing the application of LiDAR to mangrove biophysical parameter extraction at an individual tree level. The main objective of this(More)