scholarly journals Adaptive optics in laser processing

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Patrick S. Salter ◽  
Martin J. Booth
Keyword(s):  
Adaptive Optics ◽  
Intensity Distribution ◽  
Laser Processing ◽  
Ultrafast Lasers ◽  
Three Dimensional ◽  
Processing Times ◽  
The Future ◽  
Recent Developments ◽  
Focal Intensity ◽  
Adaptive Laser

AbstractAdaptive optics are becoming a valuable tool for laser processing, providing enhanced functionality and flexibility for a range of systems. Using a single adaptive element, it is possible to correct for aberrations introduced when focusing inside the workpiece, tailor the focal intensity distribution for the particular fabrication task and/or provide parallelisation to reduce processing times. This is particularly promising for applications using ultrafast lasers for three-dimensional fabrication. We review recent developments in adaptive laser processing, including methods and applications, before discussing prospects for the future.

scholarly journals Compressive Representation of Three-dimensional Models

2015 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Helton Hideraldo Bíscaro ◽  
José Paulo Lima
Keyword(s):  
Compressive Sensing ◽  
Processing Speed ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Mesh Compression ◽  
Processing Times ◽  
Recent Approach ◽  
Recent Developments ◽  
3D Scanners ◽  
Three Dimensional Models

Due to recent developments in data acquisition mechanisms, called 3d scanners, mesh compression has become an important tool for manipulating geometric data in several areas. In this context, a recent approach to the theory of signs called Compressive Sensing states that a signal can be recovered from far fewer samples than those provided by the classical theory. In this paper, we investigate the applicability of this new theory with the purpose of to obtain a compressive representation of geometric meshes. We developed an experiment which combines sampling, compression and reconstruction of various mesh sizes. Besides figuring compression rates, we also measured the relative error between the original mesh and the recovered mesh. We also compare two measurement techniques through their processing times, which are: the use of Gaussian matrices; and the use of Noiselet matrices. Gaussian matrices performed better in terms of processing speed, with equivalent performance in compression capacity. The results indicate that compressive sensing is very useful for mesh compression showing quite comparable results with traditional mesh compression techniques.

scholarly journals Three-dimensional 𝒩 = 2 supersymmetric gauge theories and partition functions on Seifert manifolds: A review

2019 ◽  
Vol 34 (23) ◽  
pp. 1930011 ◽  
Author(s):  
Cyril Closset ◽  
Heeyeon Kim
Keyword(s):  
Correlation Functions ◽  
Gauge Theories ◽  
Three Dimensional ◽  
Partition Functions ◽  
Exact Results ◽  
Strongly Coupled ◽  
Seifert Manifolds ◽  
Recent Developments ◽  
Supersymmetric Gauge ◽  
Chern Simons

We give a pedagogical introduction to the study of supersymmetric partition functions of 3D [Formula: see text] supersymmetric Chern–Simons-matter theories (with an [Formula: see text]-symmetry) on half-BPS closed three-manifolds — including [Formula: see text], [Formula: see text], and any Seifert three-manifold. Three-dimensional gauge theories can flow to nontrivial fixed points in the infrared. In the presence of 3D [Formula: see text] supersymmetry, many exact results are known about the strongly-coupled infrared, due in good part to powerful localization techniques. We review some of these techniques and emphasize some more recent developments, which provide a simple and comprehensive formalism for the exact computation of half-BPS observables on closed three-manifolds (partition functions and correlation functions of line operators). Along the way, we also review simple examples of 3D infrared dualities. The computation of supersymmetric partition functions provides exceedingly precise tests of these dualities.

Recent Developments In Monochromatic Microprobe X-Ray Fluorescence (MMXRF)

1998 ◽  
Vol 4 (S2) ◽  
pp. 378-379
Author(s):  
Z. W. Chen ◽  
D. B. Wittry
Keyword(s):  
Materials Science ◽  
High Vacuum ◽  
Three Dimensional ◽  
High Sensitivity ◽  
X Rays ◽  
Fluorescence Excitation ◽  
X Ray ◽  
Quantitative Microanalysis ◽  
Recent Developments ◽  
Fifth Order

A monochromatic x-ray microprobe based on a laboratory source has recently been developed in our laboratory and used for fluorescence excitation. This technique provides high sensitivity (ppm to ppb), nondestructive, quantitative microanalysis with minimum sample preparation and does not require a high vacuum specimen chamber. It is expected that this technique (MMXRF) will have important applications in materials science, geological sciences and biological science.Three-dimensional focusing of x-rays can be obtained by using diffraction from doubly curved crystals. In our MMXRF setup, a small x-ray source was produced by the bombardment of a selected target with a focused electron beam and a toroidal mica diffractor with Johann pointfocusing geometry was used to focus characteristic x-rays from the source. In the previous work ∼ 108 photons/s were obtained in a Cu Kα probe of 75 μm × 43 μm in the specimen plane using the fifth order reflection of the (002) planes of mica.

Recent Developments in the Evolution of Morphologies and Controllers for Physically Simulated Creatures

2001 ◽  
Vol 7 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Tim Taylor ◽  
Colm Massey
Keyword(s):  
Recent Work ◽  
Original Work ◽  
Three Dimensional ◽  
Parallel Computer ◽  
Connection Machine ◽  
Recent Developments ◽  
Body Shapes

Karl Sims' work [25, 26] on evolving body shapes and controllers for three-dimensional, physically simulated creatures generated wide interest on its publication in 1994. The purpose of this article is threefold: (a) to highlight a spate of recent work by a number of researchers in replicating, and in some cases extending, Sims' results using standard PCs (Sims' original work was done on a Connection Machine CM-5 parallel computer). In particular, a re-implementation of Sims' work by the authors will be described and discussed; (b) to illustrate how off-the-shelf physics engines can be used in this sort of work, and also to highlight some deficiencies of these engines and pitfalls when using them; and (c) to indicate how these recent studies stand in respect to Sims' original work.

Recent developments in regional transit for Greater Vancouver

1978 ◽  
Vol 5 (3) ◽  
pp. 334-339
Author(s):  
Brian E. Sullivan
Keyword(s):  
Land Use ◽  
High Rate ◽  
Low Density ◽  
Transit System ◽  
Shopping Centres ◽  
The Future ◽  
Recent Developments ◽  
Trunk Routes ◽  
The City ◽  
Capital Intensive

The transit system serving Greater Vancouver has high ridership and a high rate of growth. Using as a base the well-designed, well-patronized trolleybus grid in the City of Vancouver, an inter-connected suburban bus network has been created, with radial, cross-radial, and local routes meeting on a timed connection basis at suburban shopping centres and other foci. Planners' thoughts for the future include greater emphasis on the micro and macro aspects of land use and relations to transit; the use of capital intensive modes for heavy trunk routes; and the use of various forms of para-transit for low-density and certain feeder applications.

Recent developments in fabricating drag reduction surfaces covering biological sharkskin morphology

2016 ◽  
Vol 32 (1) ◽  
Author(s):  
Yuehao Luo ◽  
Xia Xu ◽  
Dong Li ◽  
Wen Song
Keyword(s):  
Global Warming ◽  
Drag Reduction ◽  
Rapid Development ◽  
Three Dimensional ◽  
Viscous Drag ◽  
Environment Protection ◽  
Uv Curable ◽  
Recent Developments ◽  
Potential Benefits ◽  
Energy Shortage

AbstractWith the rapid development of science and technology, increasing research interests have been focused on environment protection, global warming, and energy shortage. At present, reducing friction force as much as possible has developed into an urgent issue. Sharkskin effect has the potential ability to lower viscous drag on the fluid-solid interface in turbulence, and therefore, how to fabricate bio-inspired sharkskin surfaces is progressively becoming the hot topic. In this review, various methods of fabricating drag reduction surfaces covering biological sharkskin morphology are illustrated and discussed systematically, mainly involving direct bio-replicated, synthetic fabricating, bio/micro-rolling, enlarged solvent-swelling, drag reduction additive low-releasing, trans-scale enlarged three-dimensional fabricating, flexible printing, large-proportional shrunken bio-replicating, ultraviolet (UV) curable painting, and stretching deformed methods. The overview has the potential benefits in better acquainting with the recent research status of fabricating sharkskin surfaces covering the biological morphology.

Adaptive optics enables three-dimensional single particle tracking at the sub-millisecond scale

2013 ◽  
Vol 102 (17) ◽  
pp. 173702 ◽  
Author(s):  
Manuel F. Juette ◽  
Felix E. Rivera-Molina ◽  
Derek K. Toomre ◽  
Joerg Bewersdorf
Keyword(s):  
Adaptive Optics ◽  
Particle Tracking ◽  
Single Particle ◽  
Three Dimensional ◽  
Single Particle Tracking
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