This thesis reports the research and industry-related works carried out from the development of a fibre-optic strain sensor system for Civil Engineering applications. A sensor system consists of a number of core components, including the sensing element, interrogation/demodulation, multiplexing, signal processing and hardware equipment. In the process of development, a number of issues have been identified and investigated, which resulted in the improvement of the system performance, as well as the proposal of new techniques for the sensor system. First, an improved demodulation technique for a type of sensor, namely the fibre Fizeau interferometer (FFI), is presented. The technique is based on the improvement of the Fourier transform peak detection method, which suffers severely from the poor resolution and accuracy of finding the sensor cavity length. The improvement over the original method has been compared and verified through simulations and experiments. Second, a simultaneous demodulation technique for multiplexed FFI and fibre Bragg grating (FBG) sensors using the discrete wavelet transform (DWT) is proposed. Third, a multiplexing technique using amplitude-modulated chirped FBGs and the DWT is proposed. These two proposed techniques have been demonstrated experimentally through strain measurements. The strain resolution, crosstalk and limitations are investigated. In addition, simultaneous quasi-static strain and temperature sensing of different metal plates are performed. Fibre-optic sensors have found numerous applications in different areas. In this thesis, the use of FBG sensors in Civil Engineering applications is demonstrated in four experimental studies, including: (i) long-term measurement of drying shrinkage and creep of structural grade concrete; (ii) simultaneous measurement of shrinkage and temperature of reactive powder concrete (RPC) at early-age; (iii) measurement of coefficients of thermal expansion of cement mortar and RPC; and (iv) field-trial on the strain monitoring of the world?s first RPC road bridge. In addition, the experimental and practical issues of using FBG sensors are considered.

Thesis (Ph.D.)--Tufts University, 2001. / Advisers: Anil Saigal; Robert Greif. Submitted to the Dept. of Mechanical Engineering. Includes bibliographical references (leaves 175-177). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 156-158)

Thesis (Ph.D.)--McMaster University, 2004. / Supervisor: D.S. Wilkinson. Includes bibliographical references (leaves 164-170). Also available via World Wide Web.

Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: J. D. Embury. Includes bibliographical references (leaves 238-245).

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 84-88).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 145-154). Also available in electronic version.

Orientador: José Ricardo de Arruda Miranda / Resumo: Atividades motoras gástricas e intestinais representam um complexo grupo de funções essenciais à vida, sendo o estudo de suas características objeto de grande interesse da comunidade científica. Estudos sobre essas atividades foram intensificados em decorrência da elevada prevalência de indivíduos com sintomas atribuíveis às anormalidades dessas funções. Além disso, uma vez que os mecanismos das disfunções motoras do trato gástrico e intestinal ainda não se acham plenamente esclarecidos, faz-se necessária a busca de novas abordagens. Várias metodologias têm sido empregadas na avaliação dos parâmetros contráteis da motilidade gástrica e intestinal – uso de strain gage, métodos barométricos, elétricos e cintilográficos. A biosusceptometria de corrente alternada é um método alternativo eficaz e que apresenta grandes vantagens em relação aos demais e nesse trabalho foi comparada a técnicas consideradas padrão na avaliação da oscilação tônica do estômago e dos diferentes trechos do intestino delgado. Os resultados apresentaram valores fortemente correlacionados e concordantes entre si, permitindo quantificar a atividade tônica e o espectro de frequências predominantes nos diferentes segmentos do intestino delgado. Este trabalho aplicou uma metodologia eficiente na avaliação da oscilação tônica do estômago e do espectro de frequências predominantes no duodeno, jejuno e íleo. / Doutor

abstract: Infectious diseases are a leading cause of death worldwide. With the development of drugs, vaccines and antibiotics, it was believed that for the first time in human history diseases would no longer be a major cause of mortality. Newly emerging diseases, re-emerging diseases and the emergence of microorganisms resistant to existing treatment have forced us to re-evaluate our optimistic perspective. In this study, a simple mathematical framework for super-infection is considered in order to explore the transmission dynamics of drug-resistance. Through its theoretical analysis, we identify the conditions necessary for the coexistence between sensitive strains and drug-resistant strains. Farther, in order to investigate the effectiveness of control measures, the model is extended so as to include vaccination and treatment. The impact that these preventive and control measures may have on its disease dynamics is evaluated. Theoretical results being confirmed via numerical simulations. Our theoretical results on two-strain drug-resistance models are applied in the context of Malaria, antimalarial drugs, and the administration of a possible partially effective vaccine. The objective is to develop a monitoring epidemiological framework that help evaluate the impact of antimalarial drugs and partially-effective vaccine in reducing the disease burden at the population level. Optimal control theory is applied in the context of this framework in order to assess the impact of time dependent cost-effective treatment efforts. It is shown that cost-effective combinations of treatment efforts depend on the population size, cost of implementing treatment controls, and the parameters of the model. We use these results to identify optimal control strategies for several scenarios. / Dissertation/Thesis / Ph.D. Applied Mathematics for the Life and Social Sciences 2011