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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.
21

Hysteretic moisture characteristcs and hydraulic conductivities for glass bead media

Topp, George Clarke, January 1964 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1964. / Typescript. Vita. Description based on print version record. Includes bibliographical references (leaves 75-79).
22

Hysteresis and time-scale invariance in a glass-bead medium

Bomba, Steven James, January 1968 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
23

An Investigation of a Computer Technique for Determining the Characteristic Parameters of a Viscoelastic Model with Hysteresis Effects from Transient Experimental Data

Clark, Stephen Jack 01 June 1970 (has links)
The object of this work was to develop a computer technique for determining the characteristic parameters of spring-mass system with hysteresis effects from transient experimental data. The technique was intended to be utilized to determine the parameters of models of systems where complex geometry and rate dependent properties would make a determination of the model parameters most difficult, and where the parameters typically obtained from static test would not characterize the rate dependent properties accurately.
24

Desempenho do setor industrial exportador brasileiro pela ótica de hysteresis: (1999-2007)

Jubert, Roberto Wagner 27 March 2009 (has links)
Made available in DSpace on 2015-05-08T14:44:59Z (GMT). No. of bitstreams: 1 arquivotal.pdf: 678134 bytes, checksum: 5075c4e813b3984f78c9a46e42c8948f (MD5) Previous issue date: 2009-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This thesis had as main objective to identify the existence of hysteresis in exports of the Brazilian industrial sector. Therefore, we performed a descriptive analysis of exports (free on board), the quantities exported ( quantum ) and price indices, as well as the estimation of parameters of fractional differentiation to measure hysteresis. Of descriptive analysis is demonstrated evidence of hysteresis after the year 1999 in industrial exports, moreover, is not apparent persistence of medium-sized companies in periods of unfavorable exchange rate and persistence of large companies. The results of estimations corroborate the descriptive analysis identify hysteresis with partial effects for the period 1999-2002 and hysteresis for the period 2003-2007. Of the industries studied, two groups were prominent exporters of industrial products, with group 1 for sectors that have characterized the transition from partial to hysteresis with hysteresis effects. / Esta dissertação teve como objetivo identificar a existência de hysteresis nas exportações do setor industrial brasileiro. Portanto, foi realizada a análise descritiva das exportações ( Free on board ), das quantidades exportadas ( quantum ) e índices de preço, como também, a estimação de parâmetros de diferenciação fracionária para mensurar hysteresis. Da análise descritiva é demonstrada evidências de hysteresis após o ano de 1999 nas exportações industriais, além disso, é evidenciada não persistência das empresas de médio porte em períodos de câmbio desfavorável e persistência de empresas de grande porte. Os resultados das estimações corroboram com a análise descritiva, identificam hysteresis com efeitos parciais para o período 1999-2002 e hysteresis para o período 2003-2007. Dos setores industriais estudados, foram destacados dois grupos exportadores de produtos industriais, sendo o Grupo 1 caracterizado por setores que apresentam a transição de hysteresis com efeitos parciais para hysteresis.
25

NOVEL ANTIFREEZE PROTEIN CONSTRUCTS FOR IMPROVED ACTIVITY

Can, Ozge 23 December 2008 (has links)
No description available.
26

PID Control of Systems with Hysteresis

Shum, Alex January 2009 (has links)
Hysteresis is exhibited by many physical systems. Smart materials such as piezoelectrics, magnetostrictives and shape memory alloys possess useful properties, especially in the field of micropositioning, but the control of these systems is difficult due to the presence of hysteresis. An accurate model is required to predict the behaviour of these systems so that they can be controlled. Several hysteresis models including the backlash, elastic-plastic and Preisach operators are discussed in detail. Several other models are mentioned. Other control methods for this problem are discussed in the form of a literature review. The focus of this thesis is on the PID control of hysteretic systems. In particular, two systems experiencing hysteresis in their controllers are examined. The hysteresis in each system is described by different sets of assumptions. These assumptions are compared and found to be very similar. In the first system, a PI controller is used to track a reference signal. In the second, a PID controller is used to control a second-order system. The stability and tracking of both systems are discussed. An extension is made to the first system to include the dynamics of a first-order system. The results of the second system are verified to hold for a general first-order system. Simulations were performed with the extension to a first-order system using different hysteresis models.
27

PID Control of Systems with Hysteresis

Shum, Alex January 2009 (has links)
Hysteresis is exhibited by many physical systems. Smart materials such as piezoelectrics, magnetostrictives and shape memory alloys possess useful properties, especially in the field of micropositioning, but the control of these systems is difficult due to the presence of hysteresis. An accurate model is required to predict the behaviour of these systems so that they can be controlled. Several hysteresis models including the backlash, elastic-plastic and Preisach operators are discussed in detail. Several other models are mentioned. Other control methods for this problem are discussed in the form of a literature review. The focus of this thesis is on the PID control of hysteretic systems. In particular, two systems experiencing hysteresis in their controllers are examined. The hysteresis in each system is described by different sets of assumptions. These assumptions are compared and found to be very similar. In the first system, a PI controller is used to track a reference signal. In the second, a PID controller is used to control a second-order system. The stability and tracking of both systems are discussed. An extension is made to the first system to include the dynamics of a first-order system. The results of the second system are verified to hold for a general first-order system. Simulations were performed with the extension to a first-order system using different hysteresis models.
28

Nonlinear modelling of three phase multi limb transformers

Wu, Zhengqiu January 1998 (has links)
No description available.
29

Characterisation of the mechanisms of magnetisation change in permanent magnet materials through the interpretation of hysteresis measurements /

Harrison, Simon Andrew. January 2004 (has links)
Thesis (Ph.D.)--University of Western Australia, 2004.
30

Hysteresis phenomena of ferromagnetic bodies using the nonlocal exchange energy model /

Keane, Michael K., January 1993 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 97-99). Also available via the Internet.

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