830 research outputs found

    Linearization of an annular image by using a diffractive optic

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    The goal for this project is to develop the algorithms for fracturing the zones defined by the mapping transformation, and to actually produce the binary optic in an appropriate setup. In 1984 a side-viewing panoramic viewing system was patented, consisting of a single piece of glass with spherical surfaces which produces a 360 degree view of the region surrounding the lens which extends about 25 degrees in front of and 20 degrees behind the lens. The system not only produces images of good quality, it is also afocal, i.e., images stay in focus for objects located right next to the lens as well as those located far from the lens. The lens produced a panoramic view in an annular shaped image, and so the lens was called a PAL (panoramic annular lens). When applying traditional measurements to PAL images, it is found advantageous to linearize the annular image. This can easily be done with a computer and such a linearized image can be produced within about 40 seconds on current microcomputers. However, this process requires a frame-grabber and a computer, and is not real-time. Therefore, it was decided to try to perform this linearization optically by using a diffractive optic

    Endoscopic inspection using a panoramic annular lens

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    The objective of this one year study was to design, build, and demonstrate a prototype system for cavity inspection. A cylindrical view of the cavity interior was captured in real time through a compound lens system consisting of a unique panoramic annular lens and a collector lens. Images, acquired with a digitizing camera and stored in a desktop computer, were manipulated using image processing software to aid in visual inspection and qualitative analysis. A detailed description of the lens and its applications is given

    Endoscopic measurements using a panoramic annular lens

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    The objective of this project was to design, build, demonstrate, and deliver a prototype system for making measurements within cavities. The system was to utilize structured lighting as the means for making measurements and was to rely on a stationary probe, equipped with a unique panoramic annular lens, to capture a cylindrical view of the illuminated cavity. Panoramic images, acquired with a digitizing camera and stored in a desk top computer, were to be linearized and analyzed by mouse-driven interactive software

    MANN: A program to transfer designs for diffractive optical elements to a MANN photolithographic mask generator

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    There are two basic areas of interest for diffractive optics. In the first, the property of wavefront division is exploited for achieving optical fanout, analogous to the more familiar electrical fanout of electronic circuitry. The basic problem here is that when using a simple uniform diffraction grating the energy input is divided unevenly among the output beams. The other area of interest is the use of diffractive elements to replace or supplement standard refractive elements such as lenses. Again, local grating variations can be used to control the amount of bending imparted to optical rays, and the efficiency of the diffractive element will depend on how closely the element can be matched to the design requirements. In general, production restrictions limit how closely the element approaches the design, and for the common case of photolithographic production, a series of binary masks is required to achieve high efficiency. The actual design process is much more involved than in the case of elements for optical fanout, as the desired phase of the optical wavefront over some reference plane must be specified and the phase alteration to be introduced at each point by the diffraction element must be known. This generally requires the utilization of a standard optical design program. Two approaches are possible. In the first approach, the diffractive element is treated as a special type of lens and the ordinary optical design equations are used. Optical design programs tend to follow a second approach, namely, using the equations of optical interference derived from holographic theory and then allowing the introduction of phase front corrections in the form of polynomial equations. By using either of these two methods, diffractive elements can be used not only to compensate for distortions such as chromatic or spherical aberration, but also to perform the work of a variety of other optical elements such as null correctors, beam shapers, etc. The main focus of the project described in this report is how the design information from the lens design program is incorporated into the photolithographic process. It is shown that the MANN program, a photolithographic mask generator, fills the need for a link between lens design programs and mask generation controllers.The generated masks can be used to expose a resist-coated substrate which is etched and then must be re-coated, re-exposed, and re-etched for making copies, just as in the electronics industry

    Recent Decisions

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    Comments on recent decisions by Robert R. Waterson, Hugh E. Wall, Francis W. Matthys, Granville P. Ziegler, Thomas H. Nelson, Stanley A. Rosenstein, and John M. Doyle

    Study Protocol – Metabolic syndrome, vitamin D and bone status in South Asian women living in Auckland, New Zealand: A randomised, placebo-controlled, double-blind vitamin D intervention

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    <p>Abstract</p> <p>Background</p> <p>The identification of the vitamin D receptor in the endocrine pancreas suggests a role for vitamin D in insulin secretion. There is also some limited evidence that vitamin D influences insulin resistance, and thus the early stages of the development of type 2 diabetes.</p> <p>Methods</p> <p>Eighty-four women of South Asian origin, living in Auckland, New Zealand, were randomised to receive either a supplement (4000IU 25(OH)D<sub>3 </sub>per day) or a placebo for 6 months. At baseline, all participants were vitamin D deficient (serum 25(OH)D<sub>3 </sub><50 nmol/L), insulin resistant (HOMA-IR > 1.93) and/or hyperinsulinaemic, hyperglycemic or had clinical signs of dislipidaemia. Changes in HOMA-IR, lipids, parathyroid hormone, calcium and bone markers were monitored at 3 months and 6 months.</p> <p>Discussion</p> <p>This randomised, controlled trial will be the first to investigate the effect of vitamin D supplementation on insulin resistance in non-diabetic subjects. It will subsequently contribute to the growing body of evidence about the role of vitamin D in metabolic syndrome.Registered clinical.</p> <p>Trial registration</p> <p>Registered clinical trial – Registration No. ACTRN12607000642482</p

    De Romaanse grondvesten van de Sint-Niklaaskerk te Perk

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    EURRECA nutritional planning and dietary assessment software tool: NutPlan

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    Background/Objectives: 'NutPlan' is developed within the EURRECA Network of Excellence (EURopean micronutrient RECommendations Aligned (http://www.eurreca.org). It is a user-friendly software programme with multiple functions: individual and group nutrition planning, recipe calculation, creating food labels, diet planning and nutrient intake assessment. This paper describes the newly developed software and its features. Subjects/Methods: 'NutPlan' contains the following databases: foods, dish recipes, meals, menus, average menus and glossary. These databases enable diet planning and diet analysis by comparing foods, dishes, meals or menus with currently available nutritional recommendations accessible by a link to EURRECA tool Nutri-RecQuest to meet individual/group nutritional needs. The software is upgraded by inserting new items (for example, foods, dishes, meals) and for a connection to other software programmes, thus allowing more advanced calculations to be completed. Conclusion: 'NutPlan' might be the software of choice for individual and group diet planning. It is aimed particularly at Eastern European and West Balkan countries, which currently lack dietary software. It is envisaged for use by small and medium enterprises in the food industry, as well as by health professionals, researchers and policy makers, and can be recommended for educational purposes. Given its characteristics of being upgraded to include new country-specific food data/database, it can be recognized as an important tool in nutritional capacity development in the Central Eastern European and other regions. European Journal of Clinical Nutrition (2010) 64, S38-S42; doi:10.1038/ejcn.2010.5
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