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Automatic Generation (automatic + generation)

Distribution by Scientific Domains

Information Science and Computing	50%
Chemistry	30%
Engineering	20%

Selected Abstracts

Flow-Based Automatic Generation of Hybrid Picture Mazes

COMPUTER GRAPHICS FORUM, Issue 7 2009
Fernando J. Wong
Abstract A method for automatically generating a picture maze from two different images is introduced throughout this paper. The process begins with the extraction of salient contours and edge tangent flow information from the primary image in order to build the overall maze. Thus, mazes with passages flowing in the main edge directions and walls that effectively represent an abstract version of the primary image can be successfully created. Furthermore, our proposed approach makes possible the use of their solution path as a means of illustrating the main features of the secondary image, while attempting to keep its image motif concealed until the maze has been finally solved. The contour features and intensity of the secondary image are also incorporated into our method in order to determine the areas of the maze to be shaded by allowing the solution path to go through them. Moreover, an experiment has been conducted to confirm that solution paths can be successfully hidden from the participants in the mazes generated using our method. [source]

Automatic Generation of Structure Preserving Multiresolution Models

COMPUTER GRAPHICS FORUM, Issue 3 2005
M. Marinov
First page of article [source]

Automatic generation and evaluation of sparse protein signatures for families of protein structural domains

PROTEIN SCIENCE, Issue 1 2005
Matthew J. Blades
Abstract We identified key residues from the structural alignment of families of protein domains from SCOP which we represented in the form of sparse protein signatures. A signature-generating algorithm (SigGen) was developed and used to automatically identify key residues based on several structural and sequence-based criteria. The capacity of the signatures to detect related sequences from the SWISSPROT database was assessed by receiver operator characteristic (ROC) analysis and jack-knife testing. Test signatures for families from each of the main SCOP classes are described in relation to the quality of the structural alignments, the SigGen parameters used, and their diagnostic performance. We show that automatically generated signatures are potently diagnostic for their family (ROC50 scores typically >0.8), consistently outperform random signatures, and can identify sequence relationships in the "twilight zone" of protein sequence similarity (<40%). Signatures based on 15%,30% of alignment positions occurred most frequently among the best-performing signatures. When alignment quality is poor, sparser signatures perform better, whereas signatures generated from higher-quality alignments of fewer structures require more positions to be diagnostic. Our validation of signatures from the Globin family shows that when sequences from the structural alignment are removed and new signatures generated, the omitted sequences are still detected. The positions highlighted by the signature often correspond (alignment specificity >0.7) to the key positions in the original (non-jack-knifed) alignment. We discuss potential applications of sparse signatures in sequence annotation and homology modeling. [source]

Real-time simulation of watery paint

COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2005
Tom Van Laerhoven
Abstract Existing work on applications for thin watery paint is mostly focused on automatic generation of painterly-style images from input images, ignoring the fact that painting is a process that intuitively should be interactive. Efforts to create real-time interactive systems are limited to a single paint medium and results often suffer from a trade-off between real-timeness and simulation complexity. We report on the design of a new system that allows the real-time, interactive creation of images with thin watery paint. We mainly target the simulation of watercolor, but the system is also capable of simulating gouache and Oriental black ink. The motion of paint is governed by both physically based and heuristic rules in a layered canvas design. A final image is rendered by optically composing the layers using the Kubelka,Munk diffuse reflectance model. All algorithms that participate in the dynamics phase and the rendering phase of the simulation are implemented on graphics hardware. Images made with the system contain the typical effects that can be recognized in images produced with real thin paint, like the dark-edge effect, watercolor glazing, wet-on-wet painting and the use of different pigment types. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Training scenario prototyping for VR-based simulation of neonatal decision-making

COMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 4 2007
A. Holobar
Abstract This paper presents the design and implementation of a real-time system for virtual reality (VR)-based training in neonatal medicine, with main emphasis on simple creation of various training scenarios. This system combines an articulated 3D model of a virtual newborn with text-based descriptions of its physiological and behavioral responses, enabling medical experts to easily construct, simulate and revise an arbitrary postnatal critical situation. Afterwards, the resulting descriptions of newborn's behavior can be used for technical specifications (and even for automatic generation) of more complex behavioral models, such as finite-state automata. © 2007 wiley Periodicals, Inc. Comput Appl Eng Educ 15: 317,328, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20121 [source]

Simulation of two-phase flow with sub-scale droplet and bubble effects

COMPUTER GRAPHICS FORUM, Issue 2 2009
Viorel Mihalef
Abstract We present a new Eulerian-Lagrangian method for physics-based simulation of fluid flow, which includes automatic generation of sub-scale spray and bubbles. The Marker Level Set method is used to provide a simple geometric criterion for free marker generation. A filtering method, inspired from Weber number thresholding, further controls the free marker generation (in a physics-based manner). Two separate models are used, one for sub-scale droplets, the other for sub-scale bubbles. Droplets are evolved in a Newtonian manner, using a density-extension drag force field, while bubbles are evolved using a model based on Stokes' Law. We show that our model for sub-scale droplet and bubble dynamics is simple to couple with a full (macro-scale) Navier-Stokes two-phase flow model and is quite powerful in its applications. Our animations include coarse grained multiphase features interacting with fine scale multiphase features. [source]

Lower bound limit analysis with adaptive remeshing

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 14 2005
Andrei V. Lyamin
Abstract The objective of this work is to present an adaptive remeshing procedure for lower bound limit analysis with application to soil mechanics. Unlike conventional finite element meshes, a lower bound grid incorporates statically admissible stress discontinuities between adjacent elements. These discontinuities permit large stress jumps over an infinitesimal distance and reduce the number of elements needed to predict the collapse load accurately. In general, the role of the discontinuities is crucial as their arrangement and distribution has a dramatic influence on the accuracy of the lower bound solution (Limit Analysis and Soil Plasticity, 1975). To ensure that the discontinuities are positioned in an optimal manner requires an error estimator and mesh adaptation strategy which accounts for the presence of stress singularities in the computed stress field. Recently, Borges et al. (Int. J. Solids Struct. 2001; 38:1707,1720) presented an anisotropic mesh adaptation strategy for a mixed limit analysis formulation which used a directional error estimator. In the present work, this strategy has been tailored to suit a discontinuous lower bound formulation which employs the stresses and body forces as primary unknowns. The adapted mesh has a maximum density of discontinuities in the direction of the maximum rate of change in the stress field. For problems involving strong stress singularities in the boundary conditions (e.g. a strip footing), the automatic generation of discontinuity fans, centred on the singular points, has been implemented. The efficiency of the proposed technique is demonstrated by analysis of two classical soil mechanics problems; namely the bearing capacity of a rigid strip footing and the collapse of a vertical cut. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Oxidation of small alkenes at high temperature

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 12 2002
Barbara Heyberger
If the mechanism of formation of alkenes, the main primary products of the combustion of alkanes above 1000 K, is now well understood, their ways of degradation have been much less studied. Following a previous modeling of the oxidation of propene in a static and a jet-stirred reactors by using an automatically generated mechanism, the present paper shows new validations of the same mechanism for ignition delays in a shock tube. It also describes the extension of the rules used for the automatic generation to the case of 1-butene. The predictions of the mechanism produced for the oxidation of 1-butene are compared successfully with two sets of experimental results: the first obtained in a jet-stirred reactor between 900 and 1200 K; the second being new measurements of ignitions delays behind reflected shock waves for temperatures from 1200 up to 1670 K, pressures from 6.6 to 8.9 atm, equivalence ratios from 0.5 to 2, and with argon as bath gas. Flux and sensitivity analyses show that the role of termination reactions involving the very abundant allylic radicals is less important for 1-butene than for propene. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 666,677, 2002 [source]

PRODRG: a tool for high-throughput crystallography of protein,ligand complexes

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2004
Alexander W. Schüttelkopf
The small-molecule topology generator PRODRG is described, which takes input from existing coordinates or various two-dimensional formats and automatically generates coordinates and molecular topologies suitable for X-ray refinement of protein,ligand complexes. Test results are described for automatic generation of topologies followed by energy minimization for a subset of compounds from the Cambridge Structural Database, which shows that, within the limits of the empirical GROMOS87 force field used, structures with good geometries are generated. X-ray refinement in X-PLOR/CNS, REFMAC and SHELX using PRODRG -generated topologies produces results comparable to refinement with topologies from the standard libraries. However, tests with distorted starting coordinates show that PRODRG topologies perform better, both in terms of ligand geometry and of crystallographic R factors. [source]

A test framework for CORBA* component model-based software systems

BELL LABS TECHNICAL JOURNAL, Issue 3 2003
Harold J. Batteram
In this paper we present a framework for testing software systems that is based on the Common Object Request Broker Architecture (CORBA*) component model (CCM) standard. An important aspect of CCM-based systems is that they must be verifiable and testable at the abstract level of their design, regardless of the language chosen to implement the component. Component-based systems allow the development and testing of components to be divided among development groups working in parallel. However, dependencies between separately developed components may cause delays in testing. The test framework we present allows for the automatic generation,based on their external specification,of reactor components that testers can use as substitutes for components their components depend on, but that have not yet been developed. The test components generated can respond to an invocation interactively or automatically by means of a test script. The framework can also visualize interactions between components as they flow through a distributed system, and can compare runtime interactions with design specifications. The approach to testing that we describe was first explored in the distributed software component (DSC) framework developed as part of the FRIENDS project, and has been used successfully in the WINMAN European research project, which deals with network management applications. The test framework has now been extended and adapted for the CCM architecture. It is currently implemented as part of the COACH research project, which is sponsored by the European Commission. © 2003 Lucent Technologies Inc. [source]