Catchment Scale Recharge Modelling - Part 4

1998 ◽  
Author(s):  
TJ Hatton
Keyword(s):  
Conceptual Model ◽  
Three Dimensional ◽  
Catchment Scale ◽  
One Dimensional ◽  
Groundwater Systems ◽  
The Right ◽  
Modelling Approach

This paper addresses the need to model recharge to groundwater systems at the scale of whole catchments. It looks at developing the right conceptual model of how water moves through a given landscape for both homogeneous and heterogeneous catchments. One-dimensional recharge models and three-dimensional recharge models are considered. Discussion of which recharge modelling approach to use take in consideration of the availability of data, the nature of the questions being asked, and the expertise of the investigators.

scholarly journals A hierarchical field-level inference approach to reconstruction from sparse Lyman-α forest data

2020 ◽  
Vol 642 ◽  
pp. A139
Author(s):  
Natalia Porqueres ◽  
Oliver Hahn ◽  
Jens Jasche ◽  
Guilhem Lavaux
Keyword(s):  
Spatial Scales ◽  
Three Dimensional ◽  
Coarse Graining ◽  
Forward Model ◽  
Dynamical Model ◽  
Matter Distribution ◽  
One Dimensional ◽  
Field Level ◽  
Sparse Set ◽  
Modelling Approach

We address the problem of inferring the three-dimensional matter distribution from a sparse set of one-dimensional quasar absorption spectra of the Lyman-α forest. Using a Bayesian forward modelling approach, we focus on extending the dynamical model to a fully self-consistent hierarchical field-level prediction of redshift-space quasar absorption sightlines. Our field-level approach rests on a recently developed semiclassical analogue to Lagrangian perturbation theory (LPT), which improves over noise problems and interpolation requirements of LPT. It furthermore allows for a manifestly conservative mapping of the optical depth to redshift space. In addition, this new dynamical model naturally introduces a coarse-graining scale, which we exploited to accelerate the Markov chain Monte-Carlo (MCMC) sampler using simulated annealing. By gradually reducing the effective temperature of the forward model, we were able to allow it to first converge on large spatial scales before the sampler became sensitive to the increasingly larger space of smaller scales. We demonstrate the advantages, in terms of speed and noise properties, of this field-level approach over using LPT as a forward model, and, using mock data, we validated its performance to reconstruct three-dimensional primordial perturbations and matter distribution from sparse quasar sightlines.

Phase determination and structure refinement by density and shift functions

1970 ◽  
Vol 26 (2) ◽  
pp. 230-234 ◽  
Author(s):  
H. Jagodzinski ◽  
D. Philipp
Keyword(s):  
Crystal Structure ◽  
Structure Refinement ◽  
Three Dimensional ◽  
Complete Information ◽  
Shift Function ◽  
Model Structure ◽  
Phase Determination ◽  
One Dimensional ◽  
Structure Factors ◽  
The Right

Any crystal structure may be described in terms of a sublattice of points, each of which represents a certain fraction of the electron density. Multiplying this sublattice by a density function f(x) and applying a shift function s(x), which brings the atoms into the right positions, the correct crystal structure can be given in many different ways. It is shown that the shift function s(x) yields phase relations between the structure factors F(h), which may be evaluated directly, if the coefficients of the Fourier representation of s(x) converge rapidly. This behaviour is demonstrated for the case of a one-dimensional acentric model structure consisting of 50 atoms. Complete information on the structure may be obtained by routine methods with the aid of 5 given phases of the structure factor. This procedure may also be applied to three-dimensional structures, if the corresponding computer programs are available.

A Thermal Stress Analysis of Three-Dimensional Beams by Refined One-Dimensional Models and Strong Form Solutions

2016 ◽  
Vol 828 ◽  
pp. 139-171 ◽  
Author(s):  
Gaetano Giunta ◽  
Salim Belouettar ◽  
Erasmo Carrera
Keyword(s):  
A Priori ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Strong Form ◽  
Type Solution ◽  
One Dimensional ◽  
Solution Approach ◽  
Computational Costs ◽  
The Cross ◽  
Modelling Approach

This paper investigates the mechanical behaviour of three-dimensional beams subjected to thermal stresses.The temperature field is obtained by exactly solving Fourier's heat conduction equation and, as classically done by a staggered solution approach, it is considered as an external load within the mechanical analysis.Several higher-order beam models are derived thanks to a compact notation for the a-priori approximation of the displacement field upon the cross-section.The governing differential equations and boundary conditions are obtained in a compact nuclearform using the Principle of Virtual Displacement.The final form does not depend upon the order of approximation of the displacement fieldover the cross-section (this latter being a free parameter of the proposed modelling approach).The obtained problem is solved by means of two strong form solutions: an analytical Navier-type solution andpoint collocation (using Wendland's radial basis functions).Isotropic, functionally graded and laminated beams are considered.Results are validated towards three-dimensional FEM solution obtained by ANSYS.The proposed models yield accurate results characterised by smooth stresses thanks to the used solution methods.Furthermore, computational costs are very attractive when compared to the reference three-dimensional solutions.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

A THREE-DIMENSIONAL GEOLOGIC CONCEPTUAL MODEL BENEATH THE IDAHO NATIONAL LAB’S GEOTHERMAL RESOURCE RESEARCH AREA

2016 ◽  
Author(s):  
James T. St. Clair ◽  
◽  
Michael Janis ◽  
Robert K. Podgorney ◽  
Michael McCurry ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Three Dimensional ◽  
Research Area ◽  
Geothermal Resource ◽  
Resource Research
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