GIS-Based Probabilistic Mapping of Landslide Hazard Using a Three-Dimensional Deterministic Model

2004 ◽  
Vol 33 (2) ◽  
pp. 265-282 ◽  
Author(s):  
Mowen Xie ◽  
Tetsuro Esaki ◽  
Guoyun Zhou
2011 ◽  
Vol 16 (3) ◽  
pp. 343-364 ◽  
Author(s):  
Ranjit Kumar Upadhyay ◽  
Malay Banerjee ◽  
Rana Parshad ◽  
Sharada Nandan Raw

The main objective of the present paper is to consider the dynamical analysis of a three dimensional prey-predator model within deterministic environment and the influence of environmental driving forces on the dynamics of the model system. For the deterministic model we have obtained the local asymptotic stability criteria of various equilibrium points and derived the condition for the existence of small amplitude periodic solution bifurcating from interior equilibrium point through Hopf bifurcation. We have obtained the parametric domain within which the model system exhibit chaotic oscillation and determined the route to chaos. Finally, we have shown that chaotic oscillation disappears in presence of environmental driving forces which actually affect the deterministic growth rates. These driving forces are unable to drive the system from a regime of deterministic chaos towards a stochastically stable situation. The stochastic stability results are discussed in terms of the stability of first and second order moments. Exhaustive numerical simulations are carried out to validate the analytical findings.


2020 ◽  
Vol 19 ◽  
pp. 119
Author(s):  
M. Psaltaki ◽  
N. C. Markatos

Modelling is an important and useful tool for predicting the behaviour and the impact of pollutants on the local ecosystem parameters. More specifically, simulation and computational methods can be used for estimating the environmental impact on marine ecosystems.The paper presents a three-dimensional general deterministic model, developed to simulate and study the time-dependent behaviour of 137Cs in marine environments. The model capabilities are demonstrated by applying it at the northeast region of the island of Lemnos, in the NE Aegean Sea, Greece. Full Navier-Stokes equations for transient, three-dimensional turbulent flow, heat and mass transfer are solved numerically. The solution method is the finite-volume method and the general CFD code in which the present model is implemented is Phoenics.


Author(s):  
Xuemei Zhu ◽  
Yuming Liu

We investigate the dynamics of a three-dimensional mine-shaped body falling through water deterministically and stochastically. A physics-based deterministic model, MINE6D, is developed for the prediction of the six degree-of-freedom motion of the body falling freely through water. In MINE6D, the hydrodynamic load due to the added inertia effect is obtained exactly by using a boundary-element method while the viscous drag associated with flow separation and vortex shedding is modeled using a quasi-steady approach. Since the mine motion is found to be highly sensitive to varying the physical parameters such as body geometry, mass distribution, and initial releasing conditions, we develop a stochastic model using Monte-Carlo MINE6D simulation for the statistical analysis of mine motions in practical applications. The statistical prediction is compared with available field measurements both qualitatively and quantitatively. The characteristic features and dependence on physical parameters of the statistical prediction of mine motions are investigated. The present study is of importance to the prediction of mine burial in seabed and the design of mines.


Author(s):  
Hiroshi Imamura ◽  
Daisuke Takezaki ◽  
Masahiro Kawai ◽  
Yutaka Hasegawa ◽  
Koji Kikuyama

Vortex methods have features such as relatively simple algorithm, no grid-generation in flow field and lagrangian scheme which traces each vortex element concentrated in a tiny region. It is considered that the vortex methods are effective tools for the analysis of three-dimensional, incompressible and unsteady outer flow such as flow around wind turbines. Recently, vortex methods are employed as engineering tools for three-dimensional unsteady flow. In a flow simulation by vortex methods, accuracy of simulation depends chiefly on the vortex creation model on the wall and the viscous diffusion effects. However, it seems that the deterministic model to introduce the vortex element created on the wall into flow field has not yet been accomplished. In this paper, an introduction model of vortex elements from the wall into flow field is proposed. This model is based on the analogy of the consideration of boundary-layer. In this model, intensity of vortex elements created on the wall is determined by applying both no-through and no-slip boundary conditions and the diffusion height of each element created on the wall is determined dynamically. To investigate the applicability of the model, proposed method is applied to flow around impulsively started airfoil section.


1998 ◽  
Vol 14 (2) ◽  
pp. 190-210 ◽  
Author(s):  
Yoshiaki Takei

The purpose of the study was to identify mechanical variables that govern successful performance of the handspring with full turn vault. Subjects were 67 male gymnasts from 25 countries performing the vault during the 1992 Olympic Games. The vaults were filmed by two 16-mm Locam II DC cameras operating at 100 Hz. Approximately 80 frames per subject were digitized for each camera view. Direct linear transformation (DLT) was used to calculate the 3-D coordinates of the digitized body points. The method of Hay and Reid (1988) was used to develop a theoretical model to identify the mechanical variables that determine linear and angular motions of the vault. Significant correlations (p< .005) indicated that the following were important determinants for success: large horizontal velocity, large horizontal kinetic energy term, and overall translational kinetic energy term at takeoff from the board; short duration, small vertical displacement of the center of gravity (CG), and small somersaulting angular distance of preflight; large vertical velocity and large vertical kinetic energy term at takeoff from the horse; and large "amplitude of postflight," that is, large horizontal and vertical displacements of CG and long duration of flight; great height of CG during the second quarter-tum in postflight; and small point deduction for landing.


2020 ◽  
Author(s):  
Piotr Majka ◽  
Sylwia Bednarek ◽  
Jonathan M. Chan ◽  
Natalia Jermakow ◽  
Cirong Liu ◽  
...  

AbstractThe rapid adoption of marmosets in neuroscience has created a demand for three dimensional (3D) atlases of the brain of this species to facilitate data integration in a common reference space. We report on a new open access template of the marmoset cortex (the Nencki–Monash, or NM template), representing a morphological average of 20 brains of young adult individuals, obtained by 3D reconstructions generated from Nissl-stained serial sections. The method used to generate the template takes into account morphological features of the individual brains, as well as the borders of clearly defined cytoarchitectural areas. This has resulted in a resource which allows direct estimates of the most likely coordinates of each cortical area, as well as quantification of the margins of error involved in assigning voxels to areas, and preserves quantitative information about the laminar structure of the cortex. We provide spatial transformations between the NM and other available marmoset brain templates, thus enabling integration with magnetic resonance imaging (MRI) and tracer-based connectivity data. The NM template combines some of the main advantages of histology-based atlases (e.g. information about the cytoarchitectural structure) with features more commonly associated with MRI-based templates (isotropic nature of the dataset, and probabilistic analyses). The underlying workflow may be found useful in the future development of brain atlases that incorporate information about the variability of areas in species for which it may be impractical to ensure homogeneity of the sample in terms of age, sex and genetic background.Graphical abstractHighlightsA 3D template of the marmoset cortex representing the average of 20 individuals.The template is based on Nissl stain and preserves information about cortical layers.Probabilistic mapping of areas, cortical thickness, and layer intensity profiles.Includes spatial transformations to other marmoset brain atlases.AbbreviationsFor a list of areas and their abbreviations see Table S2.


Sign in / Sign up

Export Citation Format

Share Document