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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.
1

Performance enhancement in vertical-cavity surface-emitting lasers using focused ion beam etching

Sargent, Laurence John January 2001 (has links)
No description available.
2

Unification through coset-space dimensional reduction

Surridge, M. January 1986 (has links)
No description available.
3

Shubnikov-De Haas study in laterally constricted GaAs-AlGaAs heterojunctions£

Lakrimi, M. January 1988 (has links)
No description available.
4

Product structures and anticommuting stochastic calculus

Percy, J. D. A. January 1987 (has links)
No description available.
5

Structural and magnetic properties of some layered phosphate and phosphonate materials

Carling, Simon George January 1994 (has links)
No description available.
6

Grouping, matching and reconstruction in multiple view geometry

Schaffalitzky, Frederik January 2002 (has links)
No description available.
7

Coordenação modular: acepções contemporâneas / Modular coordination: contemporary acceptations

Crespo, Marina Rosa 23 May 2017 (has links)
A coordenação modular é um sistema para ordenação relativa de dimensões, espaços e componentes construtivos. Sua aplicação tem manifestações remotas por princípios que controlam a composição e fixam escalas convenientes para as partes e o todo, todavia foi a produção seriada industrial que determinou o papel que a disciplina teria no século XX. No Brasil, seu desenvolvimento aconteceu entre as décadas de 1950 e 1970, quando foi determinada a formatação fundamental da disciplina. Identifica-se a partir da década de 1980 um intervalo nas discussões específicas que durou até a virada do século, quando foi recuperado o interesse pela área. É consenso entre os autores que ainda não houve no Brasil sucesso na implantação de modelos abrangentes da coordenação modular, mas faltam análises atualizadas. O objetivo da dissertação - examinar o desenvolvimento da disciplina no Brasil após 1986 - está fundamentado em indícios de que as discussões recentes não se aprofundam em temas atuais e de que há um enfraquecimento de uma visão integrada do problema. As principais conclusões indicam que o desenvolvimento da construção civil vem sendo acompanhado do afastamento da arquitetura de etapas da produção, o que afeta o exercício da coordenação modular e que o programa habitacional e as ações políticas de financiamento foram determinantes para a retomada das pesquisas. Entretanto, há ecos dos modelos estabelecidos pelo setor privado, com ênfase à racionalização e à aplicação de componentes industriais. Diante disso, destaca-se que a coordenação modular, como campo da coordenação dimensional, está ligada às necessidades humanas. / Modular coordination is a system for relative ordering of dimensions, spaces, and building components. Its application presents remote manifestations through principles that control the design and set suitable scales for the parts and the whole. Nevertheless, the industrial mass production defined the role that the subject would play during the 20th century. In Brazil, its development took place between the 1960s and the 1970s; period that several authors consider decisive in what regards the subject\'s fundamental formatting. From the 1980s on, the specific debates about the matter went through a gap that lasted until the turn of the century when the interest in the field resurfaced. It is consensual among authors that Brazil still has not been successful to implement comprehensive modular coordination standards, but there is a lack of up-to-date analysis as well. The objective of the dissertation - to examine the discipline\'s development in Brazil after 1986 - is based on indications that recent discussions are leaving aside current issues and that there is a weakening of an integrated view of the matter. The main conclusions indicate that a dissociation between architecture and construction has accompanied the building industry\'s development, which affects the application of modular coordination. Moreover, the housing program and the research funding were decisive for the resumption of the field; nonetheless, there are echoes from the models established by the private sector, with emphasis on the rationalization and application of industrial components. In this context, it should be noted that modular coordination, as a field of dimensional coordination, is linked to human needs.
8

The Effect of Machining Residual Stresses on the Dimensional Stability of Aluminum Alloys used in Optical Systems

Spence, Timothy 12 April 2010 (has links)
Dimensional stability of materials is of critical importance in the fabrication of precision components used for applications such as optical systems. One source of dimensional instability is residual stress produced on the surfaces of parts due to machining operations. A creep model is proposed in this research that describes how these stressed layers affect the overall geometry of a component as they creep over time and temperature. Depth corrected XRD stress measurements and a bimetallic strip model were utilized to quantify the residual stress layer of two machining operations. The creep model parameters were determined by monitoring curvature over time and temperature. This model can be used for two purposes, the prediction of long term storage effects on part geometry for purposes of reliability assessment, and the design of short term, moderate temperature stress relief treatments. Two alloys were investigated, aluminum 6061-T6, and aluminum 4032-0. A methodology for applying the observed creep strain to complex parts using a finite element analysis is proposed.
9

Statistical Machine Learning Methods for High-dimensional Neural Population Data Analysis

Gao, Yuanjun January 2017 (has links)
Advances in techniques have been producing increasingly complex neural recordings, posing significant challenges for data analysis. This thesis discusses novel statistical methods for analyzing high-dimensional neural data. Part one discusses two extensions of state space models tailored to neural data analysis. First, we propose using a flexible count data distribution family in the observation model to faithfully capture over-dispersion and under-dispersion of the neural observations. Second, we incorporate nonlinear observation models into state space models to improve the flexibility of the model and get a more concise representation of the data. For both extensions, novel variational inference techniques are developed for model fitting, and simulated and real experiments show the advantages of our extensions. Part two discusses a fast region of interest (ROI) detection method for large-scale calcium imaging data based on structured matrix factorization. Part three discusses a method for sampling from a maximum entropy distribution with complicated constraints, which is useful for hypothesis testing for neural data analysis and many other applications related to maximum entropy formulation. We conclude the thesis with discussions and future works.
10

Bimodule theory in the study of non-self-adjoint operator algebras

Thelwall, Michael Arijan January 1989 (has links)
No description available.

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