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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

Real-time high accuracy measurement of small component dimensions

Moreland, D. J. January 1987 (has links)
No description available.
2

Remote sensing of strong emotions using electro-optical imaging technique

Hong, Kan January 2012 (has links)
This thesis reports a summary of the PhD programme for the assessment of person‘s emotional anxiety using Electro-optical technology. The thesis focuses mainly on the understanding of fundamental properties of physiological responses to emotional anxiety and how they can be captured by using Electro-optical (EO) imaging methods such as hyperspectral imaging (HSI) and thermal imaging (TI) techniques. The thesis summarises three main areas of work that have been undertaken by the author in the programme: (a) Experimental set up including HSI system and data acquisition software design and implementation, (b) fundamental understanding of physiological responses to emotional anxiety from the EO perspective and (c) the development of a novel remote sensing technique for the assessment of emotions without the requirement of base line information. One of our main results is to provide evidence to prove that the mean temperature in the periorbital region remains the same within 0.2°C during emotional anxiety. Furthermore, we have shown that it is the high temperature pixels within the periorbital, which increases in numbers by a huge amount after 2 minutes of the onset of anxiety. We have also developed techniques to allow the assessment anxiety without the need of base line information. The method has been tested using a sample size of about 40 subjects, and achieved promising result. Technologies for the remote sensing of heart beat rate has been in great demand, this study also involves the development of heart beat detection using TI system. Moreover, we have also attempted for the first time to sense glucose concentration from the blood sample in-vivo using HSI technique remotely.
3

Remote sensing of strong emotions using electro-optical imaging technique

Hong, K 08 October 2013 (has links)
This thesis reports a summary of the PhD programme for the assessment of person‘s emotional anxiety using Electro-optical technology. The thesis focuses mainly on the understanding of fundamental properties of physiological responses to emotional anxiety and how they can be captured by using Electro-optical (EO) imaging methods such as hyperspectral imaging (HSI) and thermal imaging (TI) techniques. The thesis summarises three main areas of work that have been undertaken by the author in the programme: (a) Experimental set up including HSI system and data acquisition software design and implementation, (b) fundamental understanding of physiological responses to emotional anxiety from the EO perspective and (c) the development of a novel remote sensing technique for the assessment of emotions without the requirement of base line information. One of our main results is to provide evidence to prove that the mean temperature in the periorbital region remains the same within 0.2°C during emotional anxiety. Furthermore, we have shown that it is the high temperature pixels within the periorbital, which increases in numbers by a huge amount after 2 minutes of the onset of anxiety. We have also developed techniques to allow the assessment anxiety without the need of base line information. The method has been tested using a sample size of about 40 subjects, and achieved promising result. Technologies for the remote sensing of heart beat rate has been in great demand, this study also involves the development of heart beat detection using TI system. Moreover, we have also attempted for the first time to sense glucose concentration from the blood sample in-vivo using HSI technique remotely. / ©Cranfield University
4

TWO-SURFACE OPTICAL SYSTEMS WITH ZERO THIRD-ORDER SPHERICAL ABERRATION

Stavroudis, O. N. 15 April 1969 (has links)
QC 351 A7 no. 37 / This paper derives four one-parameter families of two-surface optical systems having the property that, relative to a well-defined pair of conjugate points, one finite and the other infinite, third-order spherical aberration is zero. The two surfaces can be either refracting or reflecting. Aperture planes are defined for which third-order astigmatism is zero. An expression for coma is also derived. Assuming that the systems will be constructible, a means of defining domains for the free parameter is indicated. Possible applications of these results to optical design are included.
5

PROBLEMS IN NULL CORRECTOR DESIGN

Lytle, John D. 25 April 1969 (has links)
QC 351 A7 no. 39 / Optical systems known as "null correctors" are often required to test certain aspheric optical surfaces. This report classifies these systems on the basis of their first -order geometry and analyzes the merits of each type. The behavior of optical aberrations, especially spherical aberration, in these systems is examined in the context of computer optimization techniques, particular attention being given to some design problems unique to null correcting systems. Orthonormal concepts are applied to the problem of reducing spherical aberration in null correctors. It is shown that exceedingly simple merit functions may be constructed to streamline the optimization process. These merit functions are composed of simple linear sums of the angular spherical aberration coefficients B1, B3, B5, and B7. Thus, minimizing the following sums will improve nearly diffraction - limited systems: ( - 13 B1 + 1 B3 - g' B5 - B7) , ( 4.131 - B3 - B5) , ( - 2B1 - B3) , and ( - B1) /1-5- 3/7 3 or ( 120 B3 + 960 B5 + 840 B7 ) , ( 840 B5 + 2520 B7) , and ( 840 B7) Non -diffraction - limited systems may be optimized by minimizing the sums ( 6 B3 + 5 B5 + 5 B7) , ( p B5 + 3 B7) , and ( 1 0 B7) To demonstrate the effectiveness of the techniques discussed, the process of designing a specific null correcting system is followed in detail.
6

Métodos geométricos para a avaliação de sistemas ópticos centrados / Geometrical methods for evaluation of opticals centered systems.

Honel, Jorge 14 February 1991 (has links)
Três métodos geométricos de traçado de raios são desenvolvidos e aplicados num programa de avaliação de sistema ópticos para microcomputadores padrão IBM-PC. O primeiro método corresponde ao traçado paraxial construído a partir do Invariante de Abbe; o segundo método corresponde ao traçado meridional proposto por Rudolf Kingslake; e o terceiro método corresponde ao traçado espacial proposto por Hainz Haferkorn e Volker Tautz. Dentro do programa estão incluídas algumas das representações das aberrações ópticas que caracterizam um sistema óptico centrado. / Three methods of ray tracing are development for use on IBM PC/XT personal computer. The first method is a paraxial ray tracing derived from the invariant Abbe; the second is a meridional ray tracing proposed by Rudolf Kingslake; and the third is a skew ray tracing proposed by Heinz Haferkorn and Volker Tautz . Based on these three methods some optical aberrations are employed to exemplify an optical centered system.
7

A quasi-optical astronomical receiver

Lesurf, James Christopher George January 1981 (has links)
This thesis describes the work undertaken in producing the passive radio-frequency section of a heterodyne receiver for use on the United Kingdom Infra-Red Telescope at signal frequencies in the 200-300 GHz range. This is a Quasi-Optical system, comprised of a Martin-Puplet polarising interferometer employed as a diplexer and the lenses and feed horns by which the diplexer was coupled to the telescope, local oscillator, and mixer. The Gaussian beam-mode approach was employed to develop a theoretical basis for understanding the operation of such a system upon coherent paraxial beams. Quasi-Optical systems were then designed and their performance predicted by the application of this extension of Gaussian optics. Two such systems were constructed and their performance determined by laboratory measurements to be as predicted. One of these systems was then installed on the telescope where it was shown to function as designed. As part of the calibration and test routine on the telescope a number of astronomical measurements were made, including a determination of the apparent temperatures of the planets Jupiter and Saturn by a method different to that employed for results previously published. The Quasi-Optical receiver was successfully calibrated and commissioned as a common-user instrument. As such it will continue to be used in a variety of astronomical research programs undertaken by various groups.
8

Optical effects in photonic crystals and metamaterials

McIlhargey, James Garland 08 July 2011 (has links)
In this thesis, I will describe the polarization properties of two separate but similar optical systems. I will begin by showing anisotropy in a dielectric photonic crystal slab patterned with a periodic circular hole array. This anisotropy can be utilized in manipulating the gain properties of surface emitting photonic crystal lasers. I will then describe a metallic, planar metamaterial patterned similarly with a 2d periodic array of holes. The enhanced optical transmission of this system is demonstrated computationally and experimentally, with a good agreement between the two. I will also demonstrate polarization rotation in this array. The effect is shown to minimize the background contribution to the transmission resulting in the narrowing of the line width and improvement between on and off resonance contrast. I then provide a theory behind the polarization rotation in transmission through a metamaterial based upon a Jones matrix formulation, which is dependent only upon the existence of separate s and p resonances in a photonic system. / text
9

Análise in vitro da progressão de lesões de erosão em dentina após irradiação com laser de Nd:YAG e flúor através de tomografia por coerência óptica (OCT) / In vitro analysis of erosion progression in dentine lesions after laser irradiation of Nd:YAG and fluoride using optical coherence tomogragry (OCT)

MORAES, MARCIA C.D. de 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:42Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:00Z (GMT). No. of bitstreams: 1 17899.pdf: 5286933 bytes, checksum: dc9e220ef9d434b0d99604645076246a (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de São Paulo, São Paulo
10

Efeitos da terapia fotodinâmica (PDT) em superfícies acrílicas com biofilme / Effects of photodynamic therapy on biofilm formed on acrylic surface

EUBANK, TIAGO F. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:34:41Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:02Z (GMT). No. of bitstreams: 1 17900.pdf: 755420 bytes, checksum: b49381f0e220377f0173530306d2ddf1 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP; Faculdade de Odontologia, Universidade de São Paulo, São Paulo

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