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51 
The use of lanchestertype equations in the analysis of past military engagementsSchmieman, William Anton 08 1900 (has links)
No description available.

52 
Sensitivity of parameter values of a continuous watershed model to data errorsHassett, Timothy Donald 08 1900 (has links)
No description available.

53 
Refining and expanding the feature stamping process /Emery, Russell N., January 2005 (has links) (PDF)
Thesis (M.S.)Brigham Young University. Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (p. 8586).

54 
Parallelizing the spectral method in climate and weather modelingMelton, Roy Wayne 01 December 2003 (has links)
No description available.

55 
Alternative estimation approaches for some common Item Response Theory modelsSabouri, Pooneh, 1980 06 January 2011 (has links)
In this report we give a brief introduction to Item Response Theory models and multilevel models. The general assumptions of two classical Item Response Theory, 1PL and 2PL models are discussed. We follow the discussion by introducing a multilevel level framework for these two Item Response Theory Models. We explain Bock and Aitkin's (1981) work to estimate item parameters for these two models. Finally we illustrate these models with a LSAT exam data and two statistical softwares; R project and Stata. / text

56 
A Distributed Surface Temperature and Energy Balance Model of a SemiArid WatershedWashburne, James Clarke 05 1900 (has links)
A simple model of surface and sub surface soil temperature was developed at
the watershed scale ( 100 km2) in a semi arid rangeland environment. The model
consisted of a linear combination of air temperature and net radiation and assumed:
1) topography controls the spatial distribution of net radiation, 2) near surface air
temperature and incoming solar radiation are relatively homogeneous at the
watershed scale and are available from ground stations and 3) soil moisture
dominates transient soil thermal property variability. Multiplicative constants were
defined to account for clear sky diffuse radiation, soil thermal inertia, an initially
fixed ratio between soil heat flux and net radiation and exponential attenuation of
solar radiation through a partial canopy. The surface temperature can optionally be
adjusted for temperature and emissivity differences between mixed hare soil and
vegetation canopies. Model development stressed physical simplicity and commonly
available spatial and temporal data sets. Slowly varying surface characteristics, such
as albedo, vegetation density and topography were derived from a series of Landsat
TM images and a 7.5" USGS digital elevation model at a spatial resolution of 30 m.
Diurnally variable atmospheric parameters were derived from a pair of ground
meteorological stations using 30 60 min averages. One site was used to drive the
model, the other served as a control to estimate model error.
Data collected as part of the Monsoon '90 and WG '92 field experiments over
the ARS Walnut Gulch Experimental. Watershed in SE Arizona were used to
validate and test the model. Point, transect and spatially distributed values of modeled surface temperature were compared with synchronous ground, aircraft and
satellite thermal measurements. There was little difference between ground and
aircraft measurements of surface reflectance and temperature which makes aircraft
transects the preferred method to "ground truth" satellite observations. Mid morning
modeled surface temperatures were within 2° C of observed values at all but satellite
scales, where atmospheric water vapor corrections complicate the determination of
accurate temperatures.
The utility of satellite thermal measurements and models to study various
ground phenomena (eg. soil thermal inertia and surface energy balance) were
investigated. Soil moisture anomalies were detectable, but were more likely
associated with average near surface soil moisture levels than individual storm
footprints.

57 
Investigation of integrated terrestrial processes over the East River basin in South ChinaWu, Yiping, 吴一平 January 2009 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

58 
THREEDIMENSIONAL SEEPAGE THROUGH POROUS MEDIA WITH THE RESIDUAL FLOW PROCEDURE.BASEGHI, BEHDAD. January 1987 (has links)
The purpose of this study is to present the development and application of residual flow procedure for analysis of threedimensional (3D) steadystate and transient seepage. The finite element equations are derived using a pseudovariational principle which leads to a transient residual flow (load) vector that, in turn, is used to correct the position of the free surface iteratively. The procedure involves a fixed mesh which requires no mesh regeneration during transient analysis and during iterations. The procedure is also capable of handling material nonhomogeneities and anisotropy with relative ease. Several applications are made including verification with respect to closedform solutions, and with results from a laboratory glass bead model simulating threedimensional situations. For these glass beads, the coefficients of permeability and specific storage are also evaluated experimentally.

59 
NUMERICAL STUDIES OF BAROCLINIC INSTABILITY IN CYLINDRICAL AND SPHERICAL DOMAINS.MILLER, TIMOTHY LEE. January 1982 (has links)
Finite difference numerical models based upon the NavierStokes equations with the Boussinesq approximation have been utilized to study the dynamics of a rotating liquid with horizontal density gradients. There are two configurations analyzed: a cylindrical annulus of water rotating about a vertical axis (parallel to the body force), and a hemispherical shell of silicone oil with a radial body force, rotating about the polar axis. In both the cylindrical and spherical configurations, the thermal and mechanical forcings (boundary conditions) are symmetric about the axis of rotation. The physical parameters varied are the rotation rate and the amplitude of the horizontal thermal forcing. Two numerical models have been developed for each geometrical configuration: one to calculate axisymmetric flows and another to test the stability of those flows to nonaxisymmetric perturbations. The primary purpose of the models is to determine whether axisymmetric or nonaxisymmetric flow will be observed in a corresponding laboratory experiment. For the cylindrical annulus, the predictions of axisymmetric and nonaxisymmetric flow are in good agreement with laboratory experiments previously performed. In the spherical experiment considered, which has not been performed in the laboratory, there is evidence that if the rotation rate is fixed and the latitudinal thermal forcing is reduced, there exists a transition from nonaxisymmetric to axisymmetric flow, but that as the rotation rate is decreased for a fixed latitudinal thermal gradient on the boundaries, the flow does not become axisymmetric. The structures of some of the fastest growing eigenmodes are presented for both cylindrical and spherical cases. Analyses of the energetics indicate that the waves in all cases considered are essentially baroclinic in nature.

60 
ASYMPTOTIC PROPERTIES OF MASS TRANSPORT IN RANDOM POROUS MEDIA.WINTER, C. LARRABEE. January 1982 (has links)
Suppose C(x,t) is the concentration at position x in Rᵈ and time t > 0 of a solute which is diffusing in some medium. If on a local scale the dispersion of the solute is governed by a constant dispersion matrix, 1/2(δ²), and a random velocity field, V(x), then C satisfies a convectiondiffusion equation with random coefficients, (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) (1). Usually V(x) is taken to be μ + εU(x) where μ ε Rᵈ, U(x) is a given stationary random field with mean zero, and ε > 0 is a dimensionless parameter which measures the variability of V(x). Hydrological experiments suggest that on a regional scale the diffusion is classically Fickian with effective diffusion matrix D(ε) and drift velocity α(ε). Thus for large scales (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) (2) is satisfied by the solute concentration. Here τ and χ are respectively time and space measured on large scales. It is natural to investigate the relation of the large scale coefficients D and α to the statistical properties of V(x). To relate (1) to (2)and thus to approximate D(ε) and α(ε)it is necessary to rescale t and x and average over the distribution of V. It can then be shown that the transition form (1) to (2) is equivalent to (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) (3) where A = (∇•δ²∇)/2 + √nμ• ∇ and B(U) = √nU(√nx) • ∇. By expanding each side of (3) estimates of D(ε) and α(ε) can be obtained. The estimates have the form (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) (4). Both D₂ and α₂ depend on the power spectrum of U. Analysis shows that in at least the case of incompressible fluids D₂ is positive definite. In one dimensional transport α₂ < 0, hence α(k) < μ(k) through second order.

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