Commission V, ICWG V/IKEY WORDS: Automation, Exterior Orientation, Matching, Video, Tracking, GPS, Robust ABSTRACT:In this paper, we propose the automatic exterior orientation procedure for the Low-cost Unmanned Aerial Vehicle (UAV) photogrammetry. The Low-cost UAV has become useful tool for low altitude photogrammetry from the rapidly increasing of automatic control technique in past several years. However, automatic exterior orientation is still important issue. The most important point of automatic exterior orientation is the automatic detection of corresponding points in each still image. For this goal, the authors have developed the automatic corresponding point detection technique using both video Image and still images. The video image of this investigation is obtained with still images simultaneously. Therefore, the tracking result of video image gives robust correspondence information between each still image. Moreover, the exterior orientation procedure using GPS information from UAV and minimum ground control points have been investigated. This paper is structured as follows. At the first we describe the over view of automatic exterior orientation procedure in this investigation. As the next, the details of tracking of common feature points and robust bundle adjustment are described. Also, accuracy assessment of this automatic exterior orientation procedure is described. Finally some conclusion is given.

The 2011 off the Pacific coast of Tohoku Earthquake was one of the most powerful earthquakes on record in Japan and the huge tsunami caused by the earthquake inflicted extensive damage to the coastal areas of the Tohoku region. To form safe coastal areas, countermeasures against disaster should be developed considering not only tangible infrastructures including breakwater and bridges but also intangible measures including education on disaster prevention and the development of hazard maps. The tsunami run-up analysis is expected to play a role as one of the countermeasures against tsunami. In this research, we aim to establish a tool to effectively analyze the tsunami run-up in urban areas based on the Smoothed particle hydrodynamics (SPH) method. And then, we propose a series of pre-process procedures to develop a detailed geography analysis model that reflects the geography, elevation, and exterior shapes of buildings by referring to 3D location information and digital elevation model data obtained from a geographical information system. Finally, we established a photorealistic visualization method so that citizen can understand the tsunami phenomenon intuitively.

We study the stability of the solutions of the governing equations for soil liquefaction, assuming perturbations in the form of plane wave and of spherical wave. We model the dilatancy effect of soil for stability analysis by setting relevant components of constitutive tensors. Theoretical analysis shows that perturbations in the form of plane wave are always stable without dilatancy and can be unstable when dilatancy ratios exceed a certain critical value. We derive the critical dilatancy ratio explicitly for the plane wave case. For perturbations in the form of spherical wave, numerical simulations reveal similar dependency of stability on dilatancy ratios. As the existence of unstable solution is confirmed, our analysis provides a new perspective on possible initiation of liquefaction: a transition from stable to unstable solutions of the governing equations.

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Soil liquefaction induced by earthquakes poses a great threat to urban areas, not only by causing direct damages to infrastructures but also by delaying rescue and relief actions. Established engineering assessment methods using indices such as factor of safety against liquefaction (FL) tend to overestimate liquefaction hazards. While the standard usage of soil dynamic analysis for liquefaction assessment is limited to a single site with detailed site information. In this paper, we propose a framework based on soil dynamics for assessing liquefaction hazard for urban areas which contain numerous sites with borehole logs only. The framework is featured by generating analysis models and by estimating material parameters automatically from available borehole information. The governing equations for soil dynamics are solved by a finite element code. Liquefaction hazard is assessed according to the solutions of excess pore water pressure for given seismic waves. As demonstrations, we show simulation results of simple shear tests and of seismic response for a target site under loadings of artificial and of actual seismic waves. The automatic model construction and parameter estimation enable this framework being applied effectively for urban-area-wide liquefaction assessment, as an alternative for the current practices based on engineering indices.