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Ray Casting Curved-Quadratic Elements [article]

D. F. Wiley, H. R. Childs, B. Hamann, K. I. Joy
2004 EUROVIS 2005: Eurographics / IEEE VGTC Symposium on Visualization  
We present a method for ray casting curved-quadratic elements in 3D. The advantages of this approach is that a curved element can be directly visualized.  ...  Our method primarily focuses on how to find an approximation to the intersection between a ray and a curved-quadratic element.  ...  Curved-quadratic Elements Ray casting curved elements is more difficult than ray casting linear-edge elements, since 1) there can be more than one intersection segment per element and 2) it is difficult  ... 
doi:10.2312/vissym/vissym04/201-210 fatcat:hmbqjeergrhuxm24qjnon5boiq

Study of Inhibition Performance of a Vapor Phase Inhibitor on Rusty Iron Coins

HU Gang
2016 American Journal of Applied Chemistry  
The rust composition structure of the cast iron coins after corrosion inhibition treatment was analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).  ...  The corrosion potentials of cast iron electrode were positive shift and passivation phenomenon has been tested.  ...  Fig. 1 shows the polarization curves for cast iron electrode in different solutions. In corrosion solution with no inhibitor, the corrosion potential was -748mV.  ... 
doi:10.11648/j.ajac.20160405.18 fatcat:hons3uckojehvnyiuuyksh4srm

On Curved Simplicial Elements and Best Quadratic Spline Approximation for Hierarchical Data Representation

Bernd Hamann, Marc Herbstritt
2010 Dagstuhl Publications  
We present a method for hierarchical data approximation using curved quadratic simplicial elements for domain decomposition.  ...  Curved simplicial elements make possible a better representation of curved geometry, domain boundaries, and discontinuities than simplicial elements with non-curved edges and faces.  ...  The application of slicing methods, contouring techniques, and ray casting to non-curved quadratic elements is done routinely.  ... 
doi:10.4230/dfu.sciviz.2010.45 dblp:conf/dagstuhl/Hamann10 fatcat:ygkwgvkoavam5oi4xekp6zq5e4

Coherency-Based Curve Compression for High-Order Finite Element Model Visualization

A. Bock, E. Sunden, Bingchen Liu, B. Wunsche, T. Ropinski
2012 IEEE Transactions on Visualization and Computer Graphics  
Index Terms-Finite element visualization, GPU-based ray-casting.  ...  During ray-casting, the uniformly distributed sample points along each viewing ray must be transformed into the material space defined within each element.  ...  Wiley et al. demonstrated a technique to perform ray-casting on quadratic curved elements, but did so without regard to interactivity [36] .  ... 
doi:10.1109/tvcg.2012.206 pmid:26357139 fatcat:gnfmngzkvbglti27o45fe2x47m

Accelerating smooth molecular surface calculation

Ke Yan, Ho-Lun Cheng, Zhiwei Ji, Xin Zhang, Huijuan Lu
2017 Journal of Mathematical Biology  
Keywords Molecular modeling · Molecular skin surface · Topological disk · Quadratic patch · Bézier curve Mathematics Subject Classification 65D18 · 65D17 · 68U05 · 94B27 Availability and implementation  ...  Unlike most existing works which partition the molecular skin surface into sphere and hyperboloid patches, SFCA partitions the molecular skin surface into triangular quadratic patches and rectangular quadratic  ...  Decherchi and Rocchia (2013) used the ray-casting method to construct the molecular surface triangulation reversely.  ... 
doi:10.1007/s00285-017-1156-z pmid:28689219 fatcat:laddhblfmrhhbacckiak6qbiay

A high accuracy volume renderer for unstructured data

P.L. Williams, N.L. Max, C.M. Stein
1998 IEEE Transactions on Visualization and Computer Graphics  
This paper describes a volume rendering system for unstructured data, especially finite element data, that creates images with very high accuracy.  ...  The system will currently handle meshes whose cells are either linear or quadratic tetrahedra. Compromises or approximations are not introduced for the sake of efficiency.  ...  Inside these cells, contour surfaces will be curved, therefore, the slabs will be curved, and a viewing ray may intersect a single slab twice.  ... 
doi:10.1109/2945.675650 fatcat:5az7eiiaajekjez76yd4j4opfe

Phase Quantification of Regular and Turbo-stratified Graphite in Cast Iron by X-ray Diffractometry/Rietveld Refinement

Atsushi Ohbuchi, Kosuke Otori, Kenta Hagiwara, Yuya Koike, Toshihiro Nakamura
2021 ISIJ International  
A method to quantify regular graphite and turbo-stratified graphite (TS-graphite) forming the free carbon in ductile cast iron was developed using X-ray powder diffractometry.  ...  The calibration curve of graphite showed good linearity, with a range of 0-200 mg corresponding to the 0-5.0 mass% of graphite in the 4.00 g of the cast iron sample.  ...  Elemental analysis was performed using a Rix 3100 X-ray fluorescence spectrometer (Rigaku Co., Japan) equipped with an end-window 4 kW Rh X-ray tube operating at a tube voltage of 50 kV and tube current  ... 
doi:10.2355/isijinternational.isijint-2021-070 fatcat:2b5c2hrtwbhdlhoobxnaloz64m

Post-processing and visualization techniques for isogeometric analysis results

Annette Stahl, Trond Kvamsdal, Christian Schellewald
2017 Computer Methods in Applied Mechanics and Engineering  
casting: Rays are constructed using (42) .  ...  A per-pixel evaluation of the scalar field takes place using ray based intersection methods, like ray casting or ray tracing.  ... 
doi:10.1016/j.cma.2016.10.040 fatcat:if2uyoutlzhuxislqse2ujzvsy

A fast shadow algorithm for area light sources using backprojection

George Drettakis, Eugene Fiume
1994 Proceedings of the 21st annual conference on Computer graphics and interactive techniques - SIGGRAPH '94  
Results of the implementation show that the use of the backprojection and discontinuity meshing permits accelerated high-quality rendering of shadows using both ray-casting and polygon-rendering with interpolants  ...  Processing the quadratic curves on receiver polygons. The intersection of a plane with the quadric surface is a quadratic curve.  ...  These quadratic curves either join vertices with the same tag, or are appropriately clipped.  ... 
doi:10.1145/192161.192207 dblp:conf/siggraph/DrettakisF94 fatcat:xd3x76aj4fboxglsmugd5g7rwy

Osteology and systematic position of the Eocene salmonid †Eosalmo driftwoodensisWilson from western North America

1999 Zoological Journal of the Linnean Society  
part of frontal widely expanded above autosphenotic, (2) hyomandibular fossa on pterotic long, (3) posterior part of endopterygoid extending posteriorly and broadly overlapped by both metapterygoid and quadrate  ...  This bone inserts in the deep triangular notch of the dentary and carries a spacious and curved articulation facet for the quadrate.  ...  Judging from the cranial skeleton preserved on UALVP 13482a, this element is dorsal to the quadrate and symplectic with minimal (or no) contact with symplectic (Fig. 3A) . 27 [ 11 Smith & Stearley (1  ... 
doi:10.1006/zjls.1997.0166 fatcat:elqjgo6nsjbaxmcbp5i3lozrdm

Discontinuity meshing for accurate radiosity

D. Lischinski, F. Tampieri, D.P. Greenberg
1992 IEEE Computer Graphics and Applications  
A piecewise quadratic interpolant is used to approximate the radiance function, preserving the discontinuities associated with the edges in the mesh.  ...  algorithm that accurately reproduces the radiance across a surface by constructing a discontinuity mesh that explicitly represents various discontinuities in the radiance function as boundaries between mesh elements  ...  A displacement from the critical curve towards x results in quadratic growth in the visible source area, hence the discontinuity along that curve is D 2 .  ... 
doi:10.1109/38.163622 fatcat:na3mxsc2hvbkxiqhztizgiuhfi

Contouring Curved Quadratic Elements [article]

D. F. Wiley, H. R. Childs, B. F. Gregorski, B. Hamann, K. I. Joy
2003 EUROVIS 2005: Eurographics / IEEE VGTC Symposium on Visualization  
We show how to extract a contour line (or isosurface) from quadratic elements - specifically from quadratic triangles and tetrahedra.  ...  We also devise how to transform the resulting contour line (or surface) into a quartic curve (or surface) based on a curved-triangle (curved-tetrahedron) mapping.  ...  Conventional visualization methods, such as contouring, ray casting, and cutting-planes, can be applied directly to these linear elements.  ... 
doi:10.2312/vissym/vissym03/167-176 fatcat:koalbah5nfa7rnj6tzb25l5kkq

Three Dimensional Morphology of β-Al5FeSi Intermetallics in AlSi Alloys

P. Mikołajczak, L. Ratke
2015 Archives of Foundry Engineering  
Iron is the most common and detrimental impurity in casting alloys and has been associated with many defects.  ...  The x-ray tomography results have demonstrated Ferich phases with shapes different from simple forms such as needles or platelets and presented bent and branched phases. β grown as complicated structure  ...  hydrogen, inclusions, modifying elements and minor additions.  ... 
doi:10.1515/afe-2015-0010 fatcat:6ygli3i2ybcttoymd4qr7qwqiq

A new stem fossil characid (Teleostei: Ostariophysi) from the Eocene-Oligocene of southeastern Brazil

Fernanda E. Weiss, Maria Claudia Malabarba, Luiz R. Malabarba
2014 Neotropical Ichthyology  
, and the caudal fin with 11 ventral procurrent rays of which the anteriormost are fused in laminar bones.  ...  presence of a supraorbital, dentary with inflated pentacuspidate teeth arranged in a single row, infraorbital 3 expanded and ornamented with punctuations and grooves, a large anal fin with iii+22-23 rays  ...  In the other side of the fossil (counterpart), there is no elements preserved, only the feeble cast of the entire specimen including the most anterior region of the head.  ... 
doi:10.1590/1982-0224-20140072 fatcat:omvhqvehgrco3lb4u2io6o5o5u

Effect of Porosity on the Stiffness of Cast Steel

Richard A. Hardin, Christoph Beckermann
2007 Metallurgical and Materials Transactions. A  
The effect of porosity on the elastic behavior of cast steel is investigated experimentally, and an approach for including porosity effects in finite element analysis (FEA) simulations is presented.  ...  Porous cast steel specimens are mechanically tested having apparent elastic moduli reduced between 17 and 61 pct.  ...  Ten-node quadratic tetrahedral elements were used to perform the stress/displacement analysis.  ... 
doi:10.1007/s11661-007-9390-4 fatcat:rjy5ko2fs5bgvdavkoebhwc6ma
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