Characteristics of thermospheric infrasound predicted using ray tracing and weakly non-linear waveform analyses

2021 ◽  
Vol 149 (5) ◽  
pp. 3174-3188
Author(s):  
Philip Blom ◽  
Roger Waxler
Keyword(s):  
Ray Tracing ◽  
Non Linear

scholarly journals Non-linear arrival time tomography

1997 ◽  
Vol 40 (1) ◽  
Author(s):  
C. B. Papazachos ◽  
G. Nolet
Keyword(s):  
Ray Tracing ◽  
Large Scale ◽  
Arrival Time ◽  
Local Minima ◽  
Linear Inversion ◽  
3D Ray Tracing ◽  
Non Linear ◽  
Simple Scaling ◽  
Tracing Techniques ◽  
Stepwise Scheme

The use of 1D or pseudo- 3D ray tracing techniques in linearized tomographic problems leads to solutions for which it is difficult to assess the true resolution and error distribution. For this reason, we employ a revised 3D bending algorithm (Moser et al., 1992) and show that it can be used efficiently for a non-linear inversion in a stepwise scheme. Initial paths are determined from graph theory in order to avoid local minima in bending. The importance of 3D ray tracing in inversion studies and the limitations of the standard 1D approach are demonstrated through synthetic examples. The speed of the ray tracing and the simple scaling scheme allow for an implementation in large-scale tomographic problems.

Effect of Micro Structures of Diffusers on Optical Properties of LED Light

2012 ◽  
Vol 503 ◽  
pp. 255-259
Author(s):  
Yang Zhou ◽  
Da Ming Wu ◽  
Xiu Ting Zheng ◽  
Ya Jun Zhang ◽  
Jian Zhuang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Ray Tracing ◽  
Groove Width ◽  
Microlens Arrays ◽  
Led Light ◽  
Non Linear ◽  
Rolling Method ◽  
Simulation Results ◽  
Micro Structures

The diffusers with microlens arrays and V-cut micro structures of LED light were designed in this paper. Based on the theory of non-linear ray tracing, optical properties of the diffusers with three different micro structures were simulated by Lighttools. The three different structures are diffuser with non-structures, diffuser with 0.4mm in diameter microlens arrays and diffuser with V-cut which groove width is 0.4mm and the material of the diffusers was PP (polypropylene). Three types of diffusers were fabricated by extrusion rolling method and their transmittance and uniformity were tested. The simulation showed that diffuser with V-cut micro structures had the best transmittance and uniformity. The experiment showed that the diffusers produced by extrusion rolling method had perfect reprint effect. The simulation results and experiment results had much consistency in transmittance and uniformity. This research is helpful to solve the non-uniform luminescence and glare problems of the LED light.

B. The Non-Linear Calculations for Pulsating Stars

1967 ◽  
Vol 28 ◽  
pp. 105-176
Author(s):  
Robert F. Christy
Keyword(s):  
Major Part ◽  
Afternoon Session ◽  
Discussion Session ◽  
Pulsating Stars ◽  
Fourth Symposium ◽  
Non Linear ◽  
Considerable Discussion ◽  
Informal Approach ◽  
Preceding Session

(Ed. note: The custom in these Symposia has been to have a summary-introductory presentation which lasts about 1 to 1.5 hours, during which discussion from the floor is minor and usually directed at technical clarification. The remainder of the session is then devoted to discussion of the whole subject, oriented around the summary-introduction. The preceding session, I-A, at Nice, followed this pattern. Christy suggested that we might experiment in his presentation with a much more informal approach, allowing considerable discussion of the points raised in the summary-introduction during its presentation, with perhaps the entire morning spent in this way, reserving the afternoon session for discussion only. At Varenna, in the Fourth Symposium, several of the summaryintroductory papers presented from the astronomical viewpoint had been so full of concepts unfamiliar to a number of the aerodynamicists-physicists present, that a major part of the following discussion session had been devoted to simply clarifying concepts and then repeating a considerable amount of what had been summarized. So, always looking for alternatives which help to increase the understanding between the different disciplines by introducing clarification of concept as expeditiously as possible, we tried Christy's suggestion. Thus you will find the pattern of the following different from that in session I-A. I am much indebted to Christy for extensive collaboration in editing the resulting combined presentation and discussion. As always, however, I have taken upon myself the responsibility for the final editing, and so all shortcomings are on my head.)

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