Three-dimensional results from engineering and scientific computations often involve the display and interpretation of a large volume of complex data. A method is developed for color display of 3D data with several in...
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Three-dimensional results from engineering and scientific computations often involve the display and interpretation of a large volume of complex data. A method is developed for color display of 3D data with several interactive options to facilitate interpretation. The method is based on representing points whose values fall within a specified range as a single hue. An image is formed by overlaying successive 2D frames with increasing hue lightness towards the front. Interactive options to aid interpretations are viewpoint, contour lines, multiple range display, slicing, veiled surfaces, and stereo image pairs. The display method is successfully applied to several types of data. The overall structure and variations of the 3D data are observable, as well as transients which may be overlooked in a large input data set.
Background The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures. Methods To overcome the limitati...
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Background The FLS training tool box has now been adopted by the Society of Gastrointestinal Endoscopic Surgeons (SAGES) as an official training tool for minimally invasive procedures. Methods To overcome the limitations of the physical FLS training tool box, we have developed a Virtual Basic Laparoscopic Skill Trainer (VBLaSTTM) system, which is a 3D simulator that will allow trainees to acquire basic laparoscopic skill. Results The outcome of this work is the development of an integrated visiohaptic workstation environment including force feedback devices and a stereo display interface whereby trainees can practice on virtual versions of the FLS. Realistic graphical rendering and high fidelity haptic interactions are achieved. Conclusions Surgical skill training is a long and tedious process of acquiring fine motor skills. It is expected that residents would start on trainers such as VBLaSTTM and after reaching a certain level of competence would progress to the more complex trainers for training on specific surgical procedures. Copyright (c) 2008 John Wiley & Sons, Ltd.
The standard method of teaching color theory is cumbersome at best. computer graphics can solve problems of time and tedium and cover much more material as well.
The standard method of teaching color theory is cumbersome at best. computer graphics can solve problems of time and tedium and cover much more material as well.
A three-dimensional scan-conversion algorithm , that scan-converts 3D planar polygons into their discrete voxel-map representation within a Cubic Frame Buffer ( CFB ), is presented. The algorithm, which is a variation...
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A three-dimensional scan-conversion algorithm , that scan-converts 3D planar polygons into their discrete voxel-map representation within a Cubic Frame Buffer ( CFB ), is presented. The algorithm, which is a variation of a conventional 2D scan-line filling algorithm, is incremental and uses only simple operations like additions and tests inside the inner loops. The algorithm performs scan-conversion with computational complexity which is linear in the number of voxels written to the CFB. Another algorithm that scan-converts polygons clipped to the CFB boundaries with no added time complexity is also presented. Furthermore, an all-integer decision mechanism which makes the inner-most loop of the algorithm more efficient is discussed too. All the algorithms guarantee lack of 6-connected “tunnels” in the converted polygons. The algorithms have been implemented as part of the 3D geometry processor of the CUBE Architecture , which is a voxel-based system for 3D graphics. These algorithms allow the CUBE system to generate a discrete voxel representation of the essential 3D polygon primitive, enabling CUBE to also cater to applications generating synthetic images.
The 2.3-Angstrom crystal structure of the transcription factor NF-kappa B p50 homodimer bound to a palindromic kappa B site reveals that the Rel homology region folds into two distinct domains, similar to those in the...
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The 2.3-Angstrom crystal structure of the transcription factor NF-kappa B p50 homodimer bound to a palindromic kappa B site reveals that the Rel homology region folds into two distinct domains, similar to those in the immunoglobulin superfamily. The p50 dimer envelopes an undistorted B-DNA helix, making specific contacts along the 10-base-pair kappa B recognition site mainly through loops connecting secondary structure elements in both domains. The carboxy-terminal domains form a dimerization interface between beta-sheets using residues that are strongly conserved in the Rel family.
Hardware and software support for interactive graphics provides a variety of logical input devices. Picks and locators are the most useful types as they allow the user to interact with the graphical medium by pointin...
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Hardware and software support for interactive graphics provides a variety of logical input devices. Picks and locators are the most useful types as they allow the user to interact with the graphical medium by pointing to the area of display that is to be manipulated. The primary pick devices are light pens, joysticks, tablets, and track-balls. The interface for pick support includes commands for: 1. initialization, 2. termination, 3. enabling and disabling devices, and 4. setting the pick aperture. Methods have been developed for: 1. specifying the pick window, 2. controlling detectability, 3. resolving ambiguities when there are many items in one small area, and 4. specifying meaningful tags for picked items. An architecture for high-level pick support may include: 1. a database management system, 2. a graphical interpreter, 3. a display handler, and 4. an application program interface. Identification algorithms using geometric analysis can be used to determine the item that has been picked.
We describe how some simple properties of discrete one-forms directly relate to some old and new results concerning the parameterization of 3D mesh data. Our first result is an easy proof of Tutte's celebrated &qu...
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We describe how some simple properties of discrete one-forms directly relate to some old and new results concerning the parameterization of 3D mesh data. Our first result is an easy proof of Tutte's celebrated "spring-embedding" theorem for planar graphs, which is widely used for parameterizing meshes with the topology of a disk as a planar embedding with a convex boundary. Our second result generalizes the first, dealing with the case where the mesh contains multiple boundaries, which are free to be non-convex in the embedding. We characterize when it is still possible to achieve an embedding, despite these boundaries being non-convex. The third result is an analogous embedding theorem for meshes with genus 1 (topologically equivalent to the torus). Applications of these results to the parameterization of meshes with disk and toroidal topologies are demonstrated. Extensions to higher genus meshes are discussed. (c) 2005 Elsevier B.V. All rights reserved.
The volume of available data has been growing exponentially, increasing data problem's complexity and obscurity. In response, visual analytics (VA) has gained attention, yet its solutions haven't scaled well f...
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The volume of available data has been growing exponentially, increasing data problem's complexity and obscurity. In response, visual analytics (VA) has gained attention, yet its solutions haven't scaled well for big data. Computational methods can improve VA's scalability by giving users compact, meaningful information about the input data. However, the significant computation time these methods require hinders real-time interactive visualization of big data. By addressing crucial discrepancies between these methods and VA regarding precision and convergence, researchers have proposed ways to customize them for VA. These approaches, which include low-precision computation and iteration-level interactive visualization, ensure real-time interactive VA for big data.
In raster graphics a line must be drawn as a “discrete segment”, a set of integer grid points that lie close to the line. Equivalence classes of identically drawn lines are described in terms of Farey series; this t...
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In raster graphics a line must be drawn as a “discrete segment”, a set of integer grid points that lie close to the line. Equivalence classes of identically drawn lines are described in terms of Farey series; this treatment notably simplifies previous work of Dorst and Smeulders. A log n algorithm serves to identify a line's equivalence class. Using it to choose among precomputed n -pixel discrete segments, we may draw lines in n -pixel blocks rather than the customary single-pixel steps.
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