Two methods, one for the identification and one for the control implementation of distributed-parameter systems are presented. The methods are designed to identify and control the actual distributed system, without resorting to discretization. They are implemented using discrete sensors and actuators. The identification process is carried out in two steps. First, the eigensolution of the distributed system is identified. The lowest frequencies and associated eigenfunctions are identified using an extension of a time-domain approach developed for discrete systems. The extension to distributed systems is carried out in this dissertation. To this end, the sensors output is interpolated to identify the eigenfunctions. Next, the parameters contained in the equations of motion are identified. The motion of distributed-parameter systems is described in terms of partial differential equations, so that these parameters are in general continuous functions of the spatial variables. For vibrating systems, these parameters ordinarily represent the mass, stiffness and damping distributions. These distributions are expanded in terms of finite series of known functions of the spatial variables multiplied by undetermined coefficients. Then, using the identified eigensolution and assuming that the general nature of the equation of motion is known, use is made of the least squares method, in conjunction with the eigenfunctions orthogonality to compute the undetermined coefficients, thus identifying the actual distributed system. The control system design is based on the concept of independent modal-space control. Implementation of the independent modal-space control method requires that the number of actuators be equal to the number of controlled modes. Because the actuators are discrete elements, control spillover into the uncontrolled modes is experienced. The effect of control spillover is to pump part of the energy imparted to the distributed system into the uncontrolled modes. It is shown that when the independent modal-space control method is used, the energy required to control the controlled modes does not depend on the actuators locations, so that the placement of the actuators does not represent a serious problem, as it can for coupled controls. A new concept in extracting modal coordinates from the system output, namely modal filters, is introduced. Modal filters extract the modal quantities from the sensors data by interpolating the output of the sensors to obtain continuous displacement patterns and by performing certain weighted integrations over the distributed domain. If the interpolation functions are chosen following the same guidelines as in the finite element method, the integrations can be carried out as offline computations, which facilitates the control implementation. It is shown that when modal filters are used, control of the actual distributed system is possible and no spatial discretization is necessary. In addition, observation spillover, a possible significant problem when observers are used, is eliminated. Two numerical examples are presented to illustrate the identification and control methods. The methods described in this dissertation are in terms of vibrating systems, with special emphasis on large flexible structures. However, these methods are applicable to any distributed-parameter system. / Ph. D.

This dissertation develops two new techniques for the identification of parameters in distributed-parameter systems. The first technique identifies the physical parameter distributions such as mass, damping and stiffness. The second technique identifies the modal quantities of self-adjoint distributed-parameter systems. Distributed structures are distributed-parameter systems characterized by mass, damping and stiffness distributions. To identify the distributions, a new identification technique is introduced based on the finite element method. With this approach, the object is to identify "average" values of mass, damping and stiffness distributions over each finite element. This implies that the distributed parameters are identified only approximately, in the same way in which the finite element method approximates the behavior of a structure. It is common practice to represent the motion of a distributed parameter system by a linear combination of the associated modes of vibration. In theory, we have an infinite set of modes although, in practice we are concerned with only a finite linear combination of the modes. The modes of vibration possess certain properties which distinguish them from one another. Indeed, the modes of vibration are uncorrelated in time and orthogonal in space. The modal identification technique introduced in this dissertation uses path these spatial properties. Because both the temporal and spatial properties are used, the method does not encounter problems when the natural frequencies are closely-spaced or repeated. / Ph. D.

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 78-82).

No description available.

No description available.

Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Industrial and Systems Engineering." Includes bibliographical references (p. 181-186).

J.M. Schumacher. / Bibliography: p. 29-31. / "March, 1982"

Made available in DSpace on 2014-06-11T19:23:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-09Bitstream added on 2014-06-13T20:49:42Z : No. of bitstreams: 1 cruz_jn_me_botib.pdf: 562672 bytes, checksum: b3ad775d02dc10ea4de46942362904f0 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / São comuns experimentos conduzidos de forma a não permitir a observação do tempo exato de ocorrência do evento (por exemplo, morte), e sim o intervalo em que este ocorreu, caracterizando assim, respostas com censura intervalar. Quando os indivíduos são avaliados nos mesmos tempos, tem-se um caso particular de censura intervalar, sendo os dados deste tipo conhecidos como grupados e censurados. Dados grupados podem apresentar um grande número de empates, ou seja, proporção de empate maior que 25% (Chalita et al., 2002), podendo ser analisados considerando-se o tempo discreto e ajustando-se modelos à probabilidade de o indivíduo falhar em um certo intervalo, dado que ele sobreviveu ao intervalo anterior (Lawless, 1982). O objetivo deste trabalho é propor modelos de sobrevivência para dados grupados e censurados baseado nas distribuiçõess Weibull Generalizada (Mudhol kar et al., 1996), Log-Weibull Exponenciada (Hashimoto et al., 2010) e Log-Burr XII (Silva, 2008). Posteriormente, estes modelos e os modelos Log-Normal Generalizada e Weibull Exponenciada extendidos para dados grupados e censurados por Silveira et al. (2010), serão aplicados à um conjunto de dados referente a um estudo de pacientes submetidos a cirurgia de Duhamel-Haddad (em que os modelos Log-Normal Generalizada e Weibull Exponenciada já foram ajustados em Silveira et al. (2010)), e comparados pelo critério de Informação de Akaike Corrigido (AICс) / Experiments which are unable to accurately indicate the time of their occurrence are frequent (death, for instance) only the time they occur is related, which means answers with interval- censored . When individuals are assessed at the same time, there is a particular case interval-censored, and the data in this case is known as grouped and censored. Data of this kind can have a large number of ties whose proportions are greater than 25% (Chalita et al., 2002), and can be analyzed considering the discrete time and fitting models to the probability of the individual’s eventual failure and the timing of the failure, as he survived the previous interval (Lawless, 1982). The aim of this paper is to propose survival models data grouped based on Generalized Weibull distributions (Mudholkar et al., 1996), Log-ExponentiatedWeibull (Hashimoto et al., 2010) and Log-Burr XII (Silva, 2008). These models, the Generalized Lognormal and Weibull Exponential models extended to grouped data and censored by Silveira et al. (2010), will be applied to a data set concerning a study of patients undergoing Duhamel-Haddad surgery (whose Generalized Lognormal and Weibull Exponential models have been adjusted in Silveira et al. (2010), and compared by the Fixed Akaike information criterion (AICc)

Orientador: Liciana Vaz de Arruda Silveira / Banca: Roseli Aparecida Leandro / Banca: Lídia Raquel de Carvalho / Resumo: São comuns experimentos conduzidos de forma a não permitir a observação do tempo exato de ocorrência do evento (por exemplo, morte), e sim o intervalo em que este ocorreu, caracterizando assim, respostas com censura intervalar. Quando os indivíduos são avaliados nos mesmos tempos, tem-se um caso particular de censura intervalar, sendo os dados deste tipo conhecidos como grupados e censurados. Dados grupados podem apresentar um grande número de empates, ou seja, proporção de empate maior que 25% (Chalita et al., 2002), podendo ser analisados considerando-se o tempo discreto e ajustando-se modelos à probabilidade de o indivíduo falhar em um certo intervalo, dado que ele sobreviveu ao intervalo anterior (Lawless, 1982). O objetivo deste trabalho é propor modelos de sobrevivência para dados grupados e censurados baseado nas distribuiçõess Weibull Generalizada (Mudhol kar et al., 1996), Log-Weibull Exponenciada (Hashimoto et al., 2010) e Log-Burr XII (Silva, 2008). Posteriormente, estes modelos e os modelos Log-Normal Generalizada e Weibull Exponenciada extendidos para dados grupados e censurados por Silveira et al. (2010), serão aplicados à um conjunto de dados referente a um estudo de pacientes submetidos a cirurgia de Duhamel-Haddad (em que os modelos Log-Normal Generalizada e Weibull Exponenciada já foram ajustados em Silveira et al. (2010)), e comparados pelo critério de Informação de Akaike Corrigido (AICс) / Abstract: Experiments which are unable to accurately indicate the time of their occurrence are frequent (death, for instance) only the time they occur is related, which means answers with interval- censored . When individuals are assessed at the same time, there is a particular case interval-censored, and the data in this case is known as grouped and censored. Data of this kind can have a large number of ties whose proportions are greater than 25% (Chalita et al., 2002), and can be analyzed considering the discrete time and fitting models to the probability of the individual's eventual failure and the timing of the failure, as he survived the previous interval (Lawless, 1982). The aim of this paper is to propose survival models data grouped based on Generalized Weibull distributions (Mudholkar et al., 1996), Log-ExponentiatedWeibull (Hashimoto et al., 2010) and Log-Burr XII (Silva, 2008). These models, the Generalized Lognormal and Weibull Exponential models extended to grouped data and censored by Silveira et al. (2010), will be applied to a data set concerning a study of patients undergoing Duhamel-Haddad surgery (whose Generalized Lognormal and Weibull Exponential models have been adjusted in Silveira et al. (2010), and compared by the Fixed Akaike information criterion (AICc) / Mestre

This thesis considers the problem of robust geometric regulation for tracking and disturbance rejection of systems governed by delay differential equations. It is well known that geometric regulation can be highly sensitive to system parameters and hence such designs are not always robust. In particular, when employing numerical approximations to delay systems, the resulting finite dimensional models inherit natural approximation errors that can impact robustness. This demonstrates this lack of robustness and then addresses robustness by employing versions of robust regulation that have been developed for infinite dimensional systems. Numerical examples are given to illustrate the ideas and to test the robustness of the regulator. / M.S. / Recent years have seen a surge in the everyday application of complex mechanical and electrical systems. These systems can perform complex tasks; however, the increased complexity makes it harder to control them. An example of such a system is a semi-autonomous car designed to stay within a designated lane. One of the most commonly used approaches for controlling such systems is called output regulation. In the above example, the output regulator regulates the output of the car (position of the car) to follow the reference output (the road lane). Traditionally, the design of output regulators assumes complete knowledge of the system. However, it is impossible to derive equations that govern complex systems like a car. This thesis analyzes the robustness of output regulators in the presence of errors in the system. In particular, the focus is on analyzing output regulators implemented to delay-differential equations. These are differential equations where the rate of change of states at the current time depends on the states at previous times. Furthermore, this thesis addresses this problem by employing the robust versions of the output regulators.