126 research outputs found
Inverse Methods In Freeform Optics
Traditional methods in optical design like ray tracing suffer from slow convergence and are not constructive, i.e., each minimal perturbation of input parameters might lead to “chaotic” changes in the output. However, so-called inverse methods can be helpful in designing optical systems of reflectors and lenses. The equations in R2 become ordinary differential equations, while in R3 the equations become partial differential equations. These equations are then used to transform source distributions into target distributions, where the distributions are arbitrary, though assumed to be positive and integrable. In this project, we derive the governing equations and solve them numerically, for the systems presented by our instructor Martijn Anthonissen [Anthonissen et al. 2021]. Additionally, we show how point sources can be derived as a special case of a interval source with di- rected source interval, i.e., with each point in the source interval there is also an associated unit direction vector which could be derived from a system of two interval sources in R2. This way, it is shown that connecting source distributions with target distributions can be classified into two instead of three categories.
The resulting description of point sources as a source along an interval with directed rays could potentially be extended to three dimensions, leading to interpretations of point sources as directed sources on convex or star-shaped sets.:1 Abstract 4
2 Notation And Conventions 4
3 Introduction 5
4 ECMI Modeling Week Challenges 5
4.1 Problem 1 - Parallel to Near-Field Target 5
4.1.1 Description 5
4.1.2 Deriving The Equations 5
4.2 Problem 2 - Parallel Source To Two Targets 8
4.3 Problem 3 - Point Source To Near-Field Target 9
4.3.1 Deriving The Equations 9
4.4 Problem 4 - Point Source To Two Targets 11
5 Validation - Ray tracing 13
5.1 Splines 13
5.1.1 Piece-Wise Affine Reflectors 13
5.1.2 Piece-Wise Cubic Reflectors 14
5.2 Error Estimates For Spline Reflectors 14
5.2.1 Lemma: A Priori Feasibility Of Starting Values For Near-Field Problems 15
5.2.2 Estimates for single reflector, near-field targets 16
5.3 Ray Tracing Errors - Illumination Errors 17
5.3.1 Definition: Axioms For Errors 18
5.3.2 Extrapolated Ray Tracing Error (ERTE) 18
5.3.3 Definition: Minimal Distance Ray Tracing Error (MIRTE) 19
5.3.4 Lemma: Continuity Of The Ray Traced Reflection Projection Of Smooth Reflectors 19
5.3.5 Theorem: Convergence Of The MIRTE 20
5.3.6 Convergence Of The ERTE 21
5.3.7 Application 21
6 Numerical Implementation 21
6.1 The DOPTICS Library 21
6.2 Pseudocode Of The Implementation 21
6.2.1 Solutions Of The Problems 22
6.2.2 Ray Tracing And Ray Tracing Error 22
6.3 ERTE Implementation 25
7 Results 26
7.1 Problem 1: Results 26
7.2 Problem 2: Results 26
7.3 Problem 3: Results 27
7.4 Problem 4: Results 27
8 Generalizations In Two Dimensions 29
8.1 Directed Densities 29
8.2 Generalized, Orthogonally Emitting Sources in R2 30
8.2.1 Point Light Sources As Orthogonally Emitting Sources 30
9 Conclusion and Future Research 32
10 Group Dynamic 32
References 3
Influenza Virus Infection of the Murine Uterus: A New Model for Antiviral Immunity in the Female Reproductive Tract
Secretory IgA (S-IgA) mediates local immunity to influenza virus in the murine upper respiratory tract and may play an important role in local immunity to various microorganisms in the female reproductive tract as well. Although the presence of IgA in cervicovaginal or uterine secretions has been correlated with immunity to a number of pathogens, there has been no direct demonstration of the mediation of uterine antiviral immunity by S-IgA. Influenza virus, although not a normal pathogen of the reproductive tract, was used to develop a model for the investigation of mucosal immunity in the uterus. PR8 (H1N1) influenza virus injected into the ovarian bursa of BALB/c mice grew well, with peak titers between days 3 and 5. Intravenous injection of polymeric IgA anti-influenza virus monoclonal antibody before or 30 min after viral challenge protected mice against viral infection. We believe this work to be the first direct demonstration of S-IgA-mediated antiviral uterine immunity. It provides a model for further investigation of immunity in the female reproductive tract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63226/1/vim.2006.19.613.pd
Higher mobility in bulk semiconductors by separating the dopants from the charge-conducting band – a case study of thermoelectric PbSe
FEASIBILITY OF DEVELOPING SIMPLE CALCULATIONAL PROCEDURES FOR CHECKING HEAVY-ISOTOPE CONTENT IN OPERATING FUEL ELEMENTS.
ANALYTICAL AND EXPERIMENTAL METHODS OF DETERMINING HEAVY-ISOTOPE CONTENT OF OPERATING FUEL ELEMENTS
Seven Days of Low-Dose Orally Administered Murine Type I Interferon Does Not Cause Priming In Vivo
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