Suchada Siripant

3D Cloud and Storm Reconstruction from Satellite Image

The satellite images in Asia are produced every hour by Kochi University, Japan (URL http://weather.is.kochi-u.ac.jp/SE/00Latest.jpg). They show the development of cloud or storm movement. The sequence of satellite images can be combined to show animation easily but it is shown only from the top-view. In this paper, we propose a method to condition the 2D satellite images to be viewed from any perspective angle. The cloud or storm regions are analyzed, segmented and reconstructed to 3D cloud or storm based on the gray intensity of cloud properties. The result from reconstruction can be used for a warning system in the risky area. Typhoon Damrey (September 25 - 27, 2005) and typhoon Kaitak (October 29 - November 1, 2005) are shown as a case study of this paper. Other satellite images can be conditioned by using this approach as well.

Inverse Problem of Lindenmayer Systems on Branching Structures

Lindenmayer systems (L-systems) have been used to generate and describe the geometrical structures for example, branch structures, graph structures, both in biology and medicine. The L-systems consist of a number of iteration n, an initial string ω and a set of production rules P. The production rules are a set of predecessor a and successor χ. They are written as the form a ← χ. The production rules have been defined and analyzed from the real structure by a structure decomposition manually. The rules are compiled and transformed to represent 2D and 3D structure. However, the complicated structures are not easy to decompose and time consuming to get such production rules. In this paper, we propose an algorithm to solve this problem automatically from 2D input images by given initial pixels or voxels. The data acquisition can be retrieved from 2D image scanner, camera, CT-Scanner or MRI. The methods namely Region and Volume Growing Methods are applied to bound the target object. The skeletonization process is an important part in our reconstruction. The L-systems are reconstructed for representing the structure from 2D input image or sliced images of the volume data.

Simulation and Visualization of Plant Growth Using Lindenmayer Systems

Lindenmayer systems (L-systems) were introduced by Aristid Linden-mayer to generate geometrical structures of plants, i.e. shoot, leaf or root. During the last decade of L-systems prototypes, the plant growth has been animated by composing images from all iterations. The problem is that development of a plant model is nonsmooth and discontinuous. In this paper, we solve this problem by adding some mathematical time functions of logistic growth to each component and combine them with an L-system prototype. The stochastic and bracketed L-systems are applied to generate the stochastic structure and branching structure, respectively. Our L-system prototype can generate both plant shoot and root parts. The results of simulation and visualization are presented. These show that the simulation and visualization of the development of the plant growth modeled by using the new proposed method is smoother and more natural.

Dynamically Adaptive Tree Grid Modeling of Flood Inundation Based on Shallow Water Equations

The purpose of this paper is a computational algorithm for simulation and visualization of flood inundation on natural topography. The algorithm is constructed based on the shallow water equations, which are solved numerically using an adaptive tree grid finite volume method that is also equipped with the dynamic domain defining technique. The algorithm is tested to simulate the flood inundation in Thailand. The results are compared with the non-adaptive finest grid simulation. The comparison shows that the algorithm can reduce the number of grid cells and the computational times, without much loss of accuracy in the results.