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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Structural Continuity Effects in Steel Frames under Fire Conditions

Hoang, Ha 28 April 2010 (has links)
Fire has always been one of the most serious threats of collapse to structural building frames. The September 11 incident has stimulated significant interests in analyzing and understanding the behavior of the structures under fire events. The strength of the material decreases due to the elevated temperature caused by fire, and this reduction in strength leads to the failure of the member. Frames that do not have sufficient ductility can suffer progressive collapse of the entire structure if one member fails during a fire event. Such collapse could result in loss of human life and serious economic consequences. The motivation for this thesis is to provide an understanding of the continuity effects in steel frames under fire conditions. The continuity effects of the structure can provide additional strength to the system to sustain the loads under fire event. Different scenarios of the frame and beam structures which include changes to member sizes, fire locations, and bay size, are investigated with the assistance of SAP2000 and ANSYS. These programs can provide the collapse analysis for each scenario at different temperature. The continuity effect was investigated from the strength point of view of the structure. Ultimately, the thesis presents a design tool for aiding member design under fire conditions. The design tool consists of different graphs that maybe use to determine the collapse load capacity of a continuous structure at elevated temperature based on the analysis of a simpler, determinate structure.
12

Analysis of microwave crossing waveguide with analytic continuity mode-matching method

Chan, Chia-Ta 02 July 2010 (has links)
We show that a 3-D microwave crossing waveguide can be solved by a 2-D scalar Helmholtz equation with combining boundary conditions for TE and TM modes. Furthermore the crossing waveguide possesses a symmetry along two diagonal axes passing through the origin. Computation of the EM wave fields is decomposed into four smaller tasks of computing reflection coefficient vector of a parallel plate waveguide terminated with a corner made of two perfectly electric or magnetic conducting walls (PECW/PMCW). In this thesis, we propose a mixed Cartesian and polar coordinate mode-matching method to solve this 2-D corner cube microwave reflection problem. The solution is obtained by applying the continuity condition of both the tangential field and its normal derivative along a given curve inside the overlapped region of the two coordinate systems. We are able to compute up to the third decimal place of the reflection, through and cross transmission coefficients. All results pass the energy conservation test and are verified and compared with those computed by Integral equation method simulation.
13

An application of the continuity method for an equation on line bundles

Gonçalves, Alexandre Casassola. January 2002 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.
14

An application of the continuity method for an equation on line bundles

Gonçalves, Alexandre Casassola 28 August 2008 (has links)
Not available / text
15

Continuum theory in the eighteenth century : a historical study in the evolutionary theory of scientific change

Axelrad, Jean January 1976 (has links)
No description available.
16

Process causation and quantum physics

Ma, Cynthia Kwai Wah January 2001 (has links)
Philosophical analyses of causation take many forms but one major difficulty they all aim to address is that of the spatiotemporal continuity between causes and their effects. Bertrand Russell in 1913 brought the problem to its most transparent form and made it a case against the notion of causation in physics. The issue highlighted in Russell's argument is that of temporal contiguity between cause and effect. This tension arises from the imposition of a spectrum of discrete events occupying spacetime points upon a background of spacetime continuum. An immediate and natural solution is to superpose instead spatiotemporally continuous entities, or processes, on the spacetime continuum. This is indeed the process view of physical causation advocated by Wesley Salmon and Phil Dowe. This view takes the continuous trajectories of physical objects (worldlines) as the causal connection whereby causal influences in the form of conserved quantities are transported amongst events. Because of their reliance on spatiotemporal continuity, these theories have difficulty when confronted with the discontinuous processes in the quantum domain. This thesis is concerned with process theories. It has two parts. The first part introduces and criticizes these theories, which leads to my proposal of the History Conserved Quantity Theory with Transmission. The second part considers the extension of the idea of causal processes to quantum physics. I show how a probability distribution generated by the Schrodinger wavefunction can be regarded as a conserved quantity that makes the spacetime evolution of the wavefunction a quantum causal process. However, there are conceptual problems in the interpretation of the wavefunction, chiefly to do, as I shall argue, with the difference in the behaviours of probabilistic potentials between quantum and classical physics. I propose in the final chapter, the Feynman Path Integral formulation of quantum mechanics (with the Feynman histories) as an alternative approach to incorporating the probabilistic potentials in quantum physics. This account of how to introduce causal processes in quantum mechanics fares better, I claim, than the previous one in dealing with the situational aspect of quantum phenomena that requires the consideration of events at more than one time.
17

Concerning homogeneous plane continua

Cohen, Herman Jacob, January 1949 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 25-26).
18

Symmetrically continuous functions

Szyszkowski, Marcin. January 2000 (has links)
Thesis (Ph. D.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains iii, 56 p. Includes abstract. Includes bibliographical references (p. 54-56).
19

The isolation of certain experimental issues in the continuity controversy

Levey, Archibald Banks January 1953 (has links)
The historical development of the continuity controversy in discrimination learning is reviewed in its essential aspects as a theoretical and as an experimental problem. Some implications of the controversy are discussed and an analysis is made of the trends of experimental evidence to date. It is found that, in experiments in which a relatively simple discrimination is tested, the continuity position is generally upheld, while in complex discriminations the issues remain in doubt. A fairly detailed statement of each of the theoretical positions is presented in an effort to clarify the experimental issues and to arrive at criteria which are offered as being essential for experiments directed at the controversy. The design of such an experiment is presented. This experiment could not be completed and the possible causes of its failure are analysed. In the absence of final results the data for the initial brightness discrimination are analysed and found to yield significant results in favour of the continuity theory. It is suggested that if experiments which meet the criteria arising out of the requirements of both the theories are repeatedly found to be inoperable or inconclusive the controversy in its present form cannot be held to have operational meaning. Areas of the controversy in which further clarification of theory is needed are indicated. References are included which offer a balanced survey of the literature. / Arts, Faculty of / Philosophy, Department of / Graduate
20

On Continuity of Functions Defined on Unrestricted Point Sets

Wilson, Ural 08 1900 (has links)
This thesis is concerned with an investigation of the generalizations of continuous real functions of a real variable. In particular, the relationship between uniform continuity and ordinary continuity is concerned. The concept of uniform continuity was first introduced by Heine about 1900.

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