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The use of linear filtering in gravity and magnetic problems.Lim, Sze Hian January 1972 (has links)
No description available.
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Characterization of microstrip discontinuities by a dynamic source reversal technique using potential theoryToncich, Stanley Slavko January 1991 (has links)
No description available.
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Geometric Applications of Linear and Nonlinear Potential TheoryFogagnolo, Mattia 13 February 2020 (has links)
We provide geometric inequalities on $R^n$ and on general manifolds with nonnegative Ricci curvature by employing suitable monotone quantities along the flow of capacitary and $p$-capacitary potentials, as well as through related boundary value problems. Among the main achievements, we cite
[(i)] a Willmore-type inequality on manifolds with nonnegative Ricci curvature leading in turn to the sharp Isoperimetric Inequality on $3$-manifolds with nonnegative Ricci curvature ;
[(ii)] enhanced Kasue/Croke-Kleiner splitting theorems ;
[(iii)] a generalised Minkowski-type inequality in $R^n$ holding with no assumptions on the boundary of the domain considered except for smoothness ;
[(iv)] a complete discussion of maximal volume solutions to the least area problem with obstacle on Riemannian manifolds and its relation
with the variational $p$-capacity.
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Uppföljning av absoluta tjälrörelser : En fallstudie av väg E10 i KirunaElmehög, Hampus January 2019 (has links)
Detta examensarbete har haft som mål att undersöka tjällyftningen hos en väg i en fältstudie och utvärdera reliabiliteten hos två olika modeller för skattning av tjällyftning. Modellerna som har studerats är Trafikverkets nuvarande, vilken är implementerad i deras vägdimensioneringsverktyg PMS Objekt, samt segregation potential theory. Den studerade vägsträckan är belägen i Kiruna. I vägen har borrkärneprover tagits och vägens obundna lager, inklusive terassmaterial, har blivit analyserade i laboratorium. Dessa tester inkluderar både geoteknisk klassificering och endimensionella frysförsök på terassmaterialet. Materialets tjälfarlighet har klassificerats enligt både Trafikverkets eget och det amerikanska USACEs system. Alla prover, inklusive terrassmaterialet, består huvudsakligen av grus och sand. Enligt båda de använda klassificeringssystemen bedöms alla prover som icke tjälfarliga. Nivåmätningar utförda på vägen visar dock att tjällyftning ändå förekommer i vägen. Denna tjällyftning har inte kunnat modelleras framgångsrikt i PMS Objekt, där ingen tjällyftning alls fås trots att en dimensionerande vinter tillämpas i analysen. Däremot har en god överensstämmelse mellan bakåträknad och empiriskt beräknad tjälfarlighetsklassificering med SP0-värde enligt segregation potential theory kunnat ses. Även när detta beräknas utifrån utförda frysförsök fås en relativt god överensstämmelse. Studiens främsta fynd är att den visar på att även material som bedöms som ej tjällyftande enligt de två systemen för tjälfarlighetsklassificering faktiskt orsakar tjällyftning och att detta omfattar både terrass- och överbyggnadsmaterial. Studien visar att detta tjällyft främst beror på primärt lyft, varför klassificeringarna stämmer ganska väl om endast det sekundära lyftet avses. Studien har även visat på att Trafikverkets nuvarande modell är otillräcklig när det kommer till att modellera tjällyftning för grovkorniga jordar. Slutligen har studien även visat på möjligheten att bedöma jords tjälfarlighet med hjälp av segregation potential theory, även om också denna metod endast kan användas för att modellera sekundärt lyft. / The aim of the master thesis has been to examine the frost heaving of a road in a field study and to evaluate the reliability of two different models for estimation of frost heaving. The studied models are the current one of the Swedish Transport Administration, which is implemented in their road design tool PMS Objekt, and the segregation potential theory. The studied road section is located in Kiruna, in the northern part of Sweden. The road has been cored and the unbound layers of it, including the subgrade, have been analyzed in laboratory. These analyses include both geotechnical characterization and one-dimensional frost heave tests of the subgrade material. The frost susceptibility of the collected material has been classified according to both the Swedish Transport Administrations system and the American USACE’s system. All samples, including the subgrade, consist mainly of gravel and sand. According to both the used classification systems all samples are classified as not frost susceptible. However, the elevation measurements of the road show that frost heaving occurs in it despite this. This heaving has not been possible to model successfully in the program PMS Objekt. In it the frost heave prediction yields no heave at all, despite applying a design winter (worst case) in the analysis. A good conformity has however been observed between back-calculated and empirically evaluated frost susceptibility using segregation potential theory. A quite good conformity has also been observed when the same thing is evaluated from the preformed freeze tests. The most important finding of the study is that even material that is categorized as non-frost susceptible according to the two studied systems actually does heave. This finding includes both subgrade aswell as the unbound material in the superstructure. It has been found that the total frost heave observed in this study originates mainly from primary heaving, meaning the studied systems are quite correct in their frost susceptibility classification if only secondary heaving is intended. The study has also shown that the current model applied in PMS Objekt is poor in predicting the amount of heaving in coarse subgrades. Finally, the study has also shown the possibility to evaluate a soils frost susceptibility using segregation potential theory, although this model aswell is only applicable to secondary heave
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B-Spline Boundary Element Method for ShipsAggarwal, Aditya Mohan 07 August 2008 (has links)
The development of a three dimensional B-Spline based method, which is suitable for the steady-state potential flow analysis of free surface piercing bodies in hydrodynamics, is presented. The method requires the B-Spline or Non Uniform Rational B-Spline (NURBS) representation of the body as an input. In order to solve for the unknown potential, the source surface, both for the body as well as the free surface, is represented by NURBS surfaces. The method does not require the body surface to be discritized into flat panels. Therefore, instead of a mere panel approximation, the exact body geometry is utilized for the computation. The technique does not use a free surface Green's function, which already satisfies the linear free surface boundary conditions, but uses a separate source patch for the free surface. By eliminating the use of a free surface Green's function, the method can be extended to considering non-linear free surface conditions, thus providing the possibility for wave resistance calculations. The method is first applied to the double body flow problem around a sphere and a Wigley hull. Some comparisons are made with exact solutions to validate the accuracy of the method. Results of linear free surface conditions are then presented.
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A bi-domain model for describing ischemic myocardial d-c potentials.Tung, Leslie January 1978 (has links)
Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Bibliography: leaves 266-276. / Ph.D.
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Maxwell’s Problem on Point Charges in the PlaneKillian, Kenneth 19 June 2008 (has links)
This paper deals with approximating an upper bound for the number of equilibrium points of a potential field produced by point charges in the plane. This is a simplified form of a problem posed by Maxwell [4], who considered spatial configurations of the point charges. Using algebraic techniques, we will give an upper bound for planar charges that is sharper than the bound given in [6] for most general configurations of charges. Then we will study an example of a configuration of charges that has exactly the number of equilibrium points that Maxwell's conjecture predicts, and we will look into the nature of the extremal points in this case. We will conclude with a solution to the twin problem for the logarithmic potential, followed by a discussion of the conditions necessary for a degenerate case in the plane.
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Lagrange Interpolation on Leja PointsTaylor, Rodney 01 April 2008 (has links)
In this dissertation we investigate Lagrange interpolation. Our first result will deal with a hierarchy of interpolation schemes. Specifically, we will show that given a triangular array of points in a regular compact set K, such that the corresponding Lebesgue constants are subexponential, one always has the uniform convergence of Ln(f) to f for all functions analytic on K. We will then show that uniform convergence of Ln(f) to f for all analytic functions f is equivalent to the fact that the probability measures γn = 1/n Σn j=1 δzn,j , which are associated with our triangular array, converge weak star to the equilibrium distribution for K.
Motivated by our hierarchy, we will then come to our main result, namely that the Lebesgue constants associated with Leja sequences on fairly general compact sets are subexponential. More generally, considering Newton interpolation on a sequence of points, we will show that the weak star convergence of their corresponding probability measures to the equilibrium distribution, together with a certain distancing rule, implies that their corresponding Lebesgue constants are sub-exponential.
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Stochastic processing for enhancement of artificial insect vision / by Gregory P. Harmer.Harmer, Gregory Peter January 2001 (has links)
"November, 2001" / Includes bibliographical references (leaves 229-246) / xxiv, 254 leaves : ill. (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 2002
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Entire Solutions to Dirichlet Type ProblemsSitar, Scott January 2007 (has links)
In this thesis, we examined some Dirichlet type problems of
the form:
\begin{eqnarray*}
\triangle u & = & 0\ {\rm in\ } \mathbb{R}^n \\
u & = & f\ {\rm on\ } \psi = 0,
\end{eqnarray*}
and we were particularly interested in finding entire solutions
when entire data was prescribed. This is an extension of the work
of D. Siegel, M. Mouratidis, and M. Chamberland, who were interested
in finding polynomial solutions when polynomial data was prescribed.
In the cases where they found that polynomial solutions always existed
for any polynomial data, we tried to show that entire
solutions always existed given any entire data. For half space
problems we were successful, but when we compared this to the heat
equation, we found that we needed to impose restrictions on the type
of data allowed. For problems where data is prescribed on a pair of
intersecting lines in the plane, we found a surprising dependence
between the existence of an entire solution and the number
theoretic properties of the angle between the lines. We were
able to show that for numbers $\alpha$ with $\omega_1$ finite
according to Mahler's classification of transcendental numbers,
there will always be an entire solution given
entire data for the angle $2\alpha\pi$ between the lines.
We were also able to construct an uncountable, dense set of
angles of measure 0, much in the spirit of Liouville's number,
for which there will not always be an entire solution for all
entire data.
Finally, we investigated a problem where data is given
on the boundary of an infinite strip in the plane. We were unable to settle
this problem, but we were able to reduce it to other
{\it a priori} more tractable problems.
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