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Displaying 1-46 out of 46 total
Computing Morse-Smale Complexes with Accurate Geometry
Found in: IEEE Transactions on Visualization and Computer Graphics
By A. Gyulassy,P. Bremer,V. Pascucci
Issue Date:December 2012
pp. 2014-2022
Topological techniques have proven highly successful in analyzing and visualizing scientific data. As a result, significant efforts have been made to compute structures like the Morse-Smale complex as robustly and efficiently as possible. However, the resu...
 
Generalized Topological Simplification of Scalar Fields on Surfaces
Found in: IEEE Transactions on Visualization and Computer Graphics
By J. Tierny,V. Pascucci
Issue Date:December 2012
pp. 2005-2013
We present a combinatorial algorithm for the general topological simplification of scalar fields on surfaces. Given a scalar field f, our algorithm generates a simplified field g that provably admits only critical points from a constrained subset of the si...
 
Loop surgery for volumetric meshes: Reeb graphs reduced to contour trees
Found in: IEEE Transactions on Visualization and Computer Graphics
By J. Tierny,A. Gyulassy,E. Simon,V. Pascucci
Issue Date:November 2009
pp. 1177-1184
This paper introduces an efficient algorithm for computing the Reeb graph of a scalar function f defined on a volumetric mesh M in Ropf 3 . We introduce a procedure called
 
Interactive Exploration and Analysis of Large-Scale Simulations Using Topology-Based Data Segmentation
Found in: IEEE Transactions on Visualization and Computer Graphics
By P-T Bremer,G. Weber,J. Tierny,V. Pascucci,M. Day,J. Bell
Issue Date:September 2011
pp. 1307-1324
Large-scale simulations are increasingly being used to study complex scientific and engineering phenomena. As a result, advanced visualization and data analysis are also becoming an integral part of the scientific process. Often, a key step in extracting i...
 
A Practical Approach to Morse-Smale Complex Computation: Scalability and Generality
Found in: IEEE Transactions on Visualization and Computer Graphics
By A. Gyulassy,P.-T. Bremer,B. Hamann,V. Pascucci
Issue Date:November 2008
pp. 1619-1626
The Morse-Smale (MS) complex has proven to be a useful tool in extracting and visualizing features from scalar-valued data. However, efficient computation of the MS complex for large scale data remains a challenging problem. We describe a new algorithm and...
 
A Multi-resolution Data Structure for Two-dimensional Morse-Smale Functions
Found in: Visualization Conference, IEEE
By P.-T. Bremer, H. Edelsbrunner, B. Hamann, V. Pascucci
Issue Date:October 2003
pp. 19
We combine topological and geometric methods to construct a multi-resolution data structure for functions over two-dimensional domains. Starting with the Morse-Smale complex, we construct a topological hierarchy by progressively canceling critical points i...
 
Topology Verification for Isosurface Extraction
Found in: IEEE Transactions on Visualization and Computer Graphics
By Tiago Etiene,L. G. Nonato,C. Scheidegger,J. Tienry,T. J. Peters,V. Pascucci,R. M. Kirby,C. T. Silva
Issue Date:June 2012
pp. 952-965
The broad goals of verifiable visualization rely on correct algorithmic implementations. We extend a framework for verification of isosurfacing implementations to check topological properties. Specifically, we use stratified Morse theory and digital topolo...
 
Visual Exploration of High Dimensional Scalar Functions
Found in: IEEE Transactions on Visualization and Computer Graphics
By S Gerber,P Bremer,V Pascucci,R Whitaker
Issue Date:November 2010
pp. 1271-1280
An important goal of scientific data analysis is to understand the behavior of a system or process based on a sample of the system. In many instances it is possible to observe both input parameters and system outputs, and characterize the system as a high-...
 
Analyzing and Tracking Burning Structures in Lean Premixed Hydrogen Flames
Found in: IEEE Transactions on Visualization and Computer Graphics
By P.-T. Bremer,G.H. Weber,V. Pascucci,M. Day,J.B. Bell
Issue Date:March 2010
pp. 1-1
This paper presents topology-based methods to robustly extract, analyze, and track features defined as subsets of isosurfaces. First, we demonstrate how features identified by thresholding isosurfaces can be defined in terms of the Morse complex. Second, w...
 
Topology-Controlled Volume Rendering
Found in: IEEE Transactions on Visualization and Computer Graphics
By G.H. Weber,S.E. Dillard,H. Carr,V. Pascucci,B. Hamann
Issue Date:March 2007
pp. 330-341
Topology provides a foundation for the development of mathematically sound tools for processing and exploration of scalar fields. Existing topology-based methods can be used to identify interesting features in volumetric data sets, to find seed sets for ac...
 
Volumetric data analysis using Morse-Smale complexes
Found in: Proceedings. International Conference on Shape Modeling and Applications
By V. Natarajan,V. Pascucci
Issue Date:May 2013
pp. 320,321,322,323,324,325
The 3D Morse-Smale complex is a fundamental topological construct that partitions the domain of a real-valued function into regions having uniform gradient flow behavior. In this paper, we consider the construction and selective presentation of cells of th...
 
Direct Feature Visualization Using Morse-Smale Complexes
Found in: IEEE Transactions on Visualization and Computer Graphics
By A. Gyulassy,N. Kotava,M. Kim,C. D. Hansen,H. Hagen,V. Pascucci
Issue Date:September 2012
pp. 1549-1562
In this paper, we characterize the range of features that can be extracted from an Morse-Smale complex and describe a unified query language to extract them. We provide a visual dictionary to guide users when defining features in terms of these queries. We...
 
PIDX: Efficient Parallel I/O for Multi-resolution Multi-dimensional Scientific Datasets
Found in: 2011 IEEE International Conference on Cluster Computing
By S. Kumar,V. Vishwanath,P. Carns,B. Summa,G. Scorzelli,V. Pascucci,R. Ross,J. Chen,H. Kolla,R. Grout
Issue Date:September 2011
pp. 103-111
The IDX data format provides efficient, cache oblivious, and progressive access to large-scale scientific datasets by storing the data in a hierarchical Z (HZ) order. Data stored in IDX format can be visualized in an interactive environment allowing for me...
 
Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps
Found in: IEEE Transactions on Visualization and Computer Graphics
By H. Bhatia,S. Jadhav,P. Bremer, Guoning Chen,J. A. Levine,L. G. Nonato,V. Pascucci
Issue Date:September 2012
pp. 1383-1396
Robust analysis of vector fields has been established as an important tool for deriving insights from the complex systems these fields model. Traditional analysis and visualization techniques rely primarily on computing streamlines through numerical integr...
 
Comments on the "Meshless Helmholtz-Hodge Decomposition"
Found in: IEEE Transactions on Visualization and Computer Graphics
By H. Bhatia,G. Norgard,V. Pascucci,P. Bremer
Issue Date:March 2013
pp. 527-528
The Helmholtz-Hodge decomposition (HHD) is one of the fundamental theorems of fluids describing the decomposition of a flow field into its divergence-free, curl-free, and harmonic components. Solving for the HHD is intimately connected to the choice of bou...
 
Branching and Circular Features in High Dimensional Data
Found in: IEEE Transactions on Visualization and Computer Graphics
By Bei Wang,B. Summa,V. Pascucci,M. Vejdemo-Johansson
Issue Date:December 2011
pp. 1902-1911
Large observations and simulations in scientific research give rise to high-dimensional data sets that present many challenges and opportunities in data analysis and visualization. Researchers in application domains such as engineering, computational biolo...
 
A Topological Framework for the Interactive Exploration of Large Scale Turbulent Combustion
Found in: 2009 5th IEEE International Conference on e-Science (e-Science 2009)
By P.-T. Bremer,G.H. Weber,J. Tierny,V. Pascucci,M.S. Day,J.B. Bell
Issue Date:December 2009
pp. 247-254
The advent of highly accurate, large scale volumetric simulations has made data analysis and visualization techniques an integral part of the modern scientific process. To develop new insights from raw data, scientists need the ability to define features o...
 
The Helmholtz-Hodge Decomposition—A Survey
Found in: IEEE Transactions on Visualization and Computer Graphics
By H. Bhatia,G. Norgard,V. Pascucci,Peer-Timo Bremer
Issue Date:August 2013
pp. 1386-1404
The Helmholtz-Hodge Decomposition (HHD) describes the decomposition of a flow field into its divergence-free and curl-free components. Many researchers in various communities like weather modeling, oceanology, geophysics, and computer graphics are interest...
 
Topological analysis and visualization of cyclical behavior in memory reference traces
Found in: 2012 IEEE Pacific Visualization Symposium (PacificVis)
By A. N. M. I. Choudhury, Bei Wang,P. Rosen,V. Pascucci
Issue Date:February 2012
pp. 9-16
We demonstrate the application of topological analysis techniques to the rather unexpected domain of software visualization. We collect a memory reference trace from a running program, recasting the linear flow of trace records as a high-dimensional point ...
 
Streaming Simplification of Tetrahedral Meshes
Found in: IEEE Transactions on Visualization and Computer Graphics
By H.T. Vo,S.P. Callahan,P. Lindstrom,V. Pascucci,C.T. Silva
Issue Date:January 2007
pp. 145-155
Unstructured tetrahedral meshes are commonly used in scientific computing to represent scalar, vector, and tensor fields in three dimensions. Visualization of these meshes can be difficult to perform interactively due to their size and complexity. By reduc...
 
Visualization of Scalar Topology for Structural Enhancement
Found in: Visualization Conference, IEEE
By C. L. Bajaj, V. Pascucci, D. R. Schikore
Issue Date:October 1998
pp. 51
Scalar fields arise in every scientific application. Existing scalar visualization techniques require that the user infer the global scalar structure from what is frequently an insufficient display of information. We present a visualization technique which...
 
Interpreting Performance Data across Intuitive Domains
Found in: 2011 International Conference on Parallel Processing
By M. Schulz,J. A. Levine,P-T Bremer,T. Gamblin,V. Pascucci
Issue Date:September 2011
pp. 206-215
To exploit the capabilities of current and future systems, developers must understand the interplay between on-node performance, domain decomposition, and an application's intrinsic communication patterns. While tools exist to gather and analyze data for e...
 
Efficient Computation of the Topology of Level Sets
Found in: Visualization Conference, IEEE
By V. Pascucci, K. Cole-McLaughlin
Issue Date:November 2002
pp. N/A
<div>This paper introduces two efficient algorithms that compute the Contour Tree of a 3D scalar field F and its augmented version with the Betti numbers of each isosurface. The Contour Tree is a fundamental data structure in scientific visualization...
 
Implicit occluders
Found in: IEEE Symposium on Volume Visualization and Graphics 2004
By S. Pesco,P. Lindstrom,V. Pascucci,C.T. Silva
Issue Date:May 2013
pp. 47-54
In this paper we propose a novel visibility-culling technique for optimizing the computation and rendering of opaque isosurfaces. Given a continuous scalar field f(x) over a domain D and an iso-value w, our technique exploits the continuity of f to determi...
 
Hybrid CPU-GPU Solver for Gradient Domain Processing of Massive Images
Found in: 2011 IEEE 17th International Conference on Parallel and Distributed Systems (ICPADS 2011)
By S. Philip,B. Summa,V. Pascucci,P-T Bremer
Issue Date:December 2011
pp. 244-251
Gradient domain processing is a computationally expensive image processing technique. Its use for processing massive images, giga or terapixels in size, can take several hours with serial techniques. To address this challenge, parallel algorithms are being...
 
Enabling Advanced Visualization Tools in a Web-Based Simulation Monitoring System
Found in: 2009 5th IEEE International Conference on e-Science (e-Science 2009)
By E. Santos,J. Tierny,A. Khan,B. Grimm,L. Lins,J. Freire,V. Pascucci,C.T. Silva,S. Klasky,R. Barreto,N. Podhorszki
Issue Date:December 2009
pp. 358-365
Simulations that require massive amounts of computing power and generate tens of terabytes of data are now part of the daily lives of scientists. Analyzing and visualizing the results of these simulations as they are computed can lead not only to early ins...
 
Efficient Computation of Morse-Smale Complexes for Three-dimensional Scalar Functions
Found in: IEEE Transactions on Visualization and Computer Graphics
By A. Gyulassy,V. Natarajan,V. Pascucci,B. Hamann
Issue Date:November 2007
pp. 1440-1447
The Morse-Smale complex is an efficient representation of the gradient behavior of a scalar function, and critical points paired by the complex identify topological features and their importance. We present an algorithm that constructs the Morse-Smale comp...
 
Time Critical Isosurface Refinement and Smoothing
Found in: Volume Visualization and Graphics, IEEE Symposium on
By C. L. Bajaj, V. Pascucci
Issue Date:October 2000
pp. 33-42
<p>Multi-resolution data-structures and algorithms are key in Visualization to achieve real-time interaction with large data-sets. Research has been primarily focused on the off-line construction of such representations mostly using decimation scheme...
 
Parallel accelerated isocontouring for out-of-core visualization
Found in: Parallel and Large-Data Visualization and Graphics, IEEE Symposium on
By X. Y. Zhang, V. Pascucci, D. Thompson, C. L. Bajaj
Issue Date:October 1999
pp. 97-104
In this paper we introduce a scheme for static analysis that allows us to partition large geometric datasets at multiple levels of granularity to achieve both load balancing in parallel computations and minimal access to secondary memory in out-of-core com...
 
Global Static Indexing for Real-Time Exploration of Very Large Regular Grids
Found in: 2011 24th SIBGRAPI Conference on Graphics, Patterns and Images (SIBGRAPI 2011)
By V. Pascucci,R.J. Frank
Issue Date:May 2013
pp. 45
In this paper we introduce a new indexing scheme for progressive traversal and visualization of large regular grids. We demonstrate the potential of our approach by providing a tool that displays at interactive rates planar slices of scalar field data with...
 
Visualizing Network Traffic to Understand the Performance of Massively Parallel Simulations
Found in: IEEE Transactions on Visualization and Computer Graphics
By A. G. Landge,J. A. Levine,A. Bhatele,K. E. Isaacs,T. Gamblin,M. Schulz,S. H. Langer,Peer-Timo Bremer,V. Pascucci
Issue Date:December 2012
pp. 2467-2476
The performance of massively parallel applications is often heavily impacted by the cost of communication among compute nodes. However, determining how to best use the network is a formidable task, made challenging by the ever increasing size and complexit...
 
Adaptive Extraction and Quantification of Geophysical Vortices
Found in: IEEE Transactions on Visualization and Computer Graphics
By S. Williams,M. Petersen,P.-T Bremer,M. Hecht,V. Pascucci,J. Ahrens,M. Hlawitschka,B. Hamann
Issue Date:December 2011
pp. 2088-2095
We consider the problem of extracting discrete two-dimensional vortices from a turbulent flow. In our approach we use a reference model describing the expected physics and geometry of an idealized vortex. The model allows us to derive a novel correlation b...
 
Combinatorial Laplacian Image Cloning
Found in: 2011 24th SIBGRAPI Conference on Graphics, Patterns and Images (SIBGRAPI 2011)
By Alex Cuadros Vargas,L. G. Nonato,V. Pascucci
Issue Date:August 2011
pp. 236-241
Seamless image cloning has become one of the most important editing operation for photomontage. Recent coordinate-based methods have lessened considerably the computational cost of image cloning, thus enabling interactive applications. However, those techn...
 
Ensemble-Vis: A Framework for the Statistical Visualization of Ensemble Data
Found in: 2009 IEEE International Conference on Data Mining Workshops (ICDMW 2009)
By K. Potter,A. Wilson,P.-T. Bremer,D. Williams,C. Doutriaux,V. Pascucci,C.R. Johnson
Issue Date:December 2009
pp. 233-240
Scientists increasingly use ensemble data sets to explore relationships present in dynamic systems. Ensemble data sets combine spatio-temporal simulation results generated using multiple numerical models, sampled input conditions and perturbed parameters. ...
 
Visualization Corner: Robust Topology-Based Multiscale Analysis of Scientific Data
Found in: Computing in Science & Engineering
By A. Gyulassy,L.G. Nonato,P.-T. Bremer,C. Silva,V. Pascucci
Issue Date:September 2009
pp. 88-95
During multiscale analysis, hierarchical function decompositions and error-driven simplifications can't guarantee precise control of topological features. Topology-based multiscale analysis has emerged as an alternative to help researchers understand compl...
 
Hypervolume Visualization: A Challenge in Simplicity
Found in: Volume Visualization and Graphics, IEEE Symposium on
By V. Pascucci, D. Schikorc, G. Rabbiolo, C. L. Bajaj
Issue Date:October 1998
pp. 95-102
<p>Hyper-volume visualization is designed to provide simple and fully explanatory images that give comprehensive insights into the global structure of scalar fields of any dimension. The basic idea is to have a dimension independent viewing system th...
 
The Parallel Computation of Morse-Smale Complexes
Found in: 2012 IEEE International Symposium on Parallel & Distributed Processing (IPDPS)
By A. Gyulassy,V. Pascucci,T. Peterka,R. Ross
Issue Date:May 2012
pp. 484-495
Topology-based techniques are useful for multiscale exploration of the feature space of scalar-valued functions, such as those derived from the output of large-scale simulations. The Morse-Smale (MS) complex, in particular, allows robust identification of ...
 
Topologically Clean Distance Fields
Found in: IEEE Transactions on Visualization and Computer Graphics
By A.G. Gyulassy,M.A. Duchaineau, Vijay Natarajan,V. Pascucci,E.M. Bringa,A. Higginbotham,B. Hamann
Issue Date:November 2007
pp. 1432-1439
Analysis of the results obtained from material simulations is important in the physical sciences. Our research was motivated by the need to investigate the properties of a simulated porous solid as it is hit by a projectile. This paper describes two techni...
 
Topological Landscapes: A Terrain Metaphor for Scientific Data
Found in: IEEE Transactions on Visualization and Computer Graphics
By G.H. Weber,P.-T. Bremer,V. Pascucci
Issue Date:November 2007
pp. 1416-1423
Scientific visualization and illustration tools are designed to help people understand the structure and complexity of scientific data with images that are as informative and intuitive as possible. In this context the use of metaphors plays an important ro...
 
Understanding the Structure of the Turbulent Mixing Layer in Hydrodynamic Instabilities
Found in: IEEE Transactions on Visualization and Computer Graphics
By D. Laney,P.-T. Bremer,A. Mascarenhas,P. Miller,V. Pascucci
Issue Date:September 2006
pp. 1053-1060
When a heavy fluid is placed above a light fluid, tiny vertical perturbations in the interface create a characteristic structure of rising bubbles and falling spikes known as Rayleigh-Taylor instability. Rayleigh-Taylor instabilities have received much att...
 
Product operator on cell complexes
Found in: Proceedings on the second ACM symposium on Solid modeling and applications (SMA '93)
By A. Paoluzzi, F. Bernardini, V. Ferrucci, V. Pascucci
Issue Date:May 1993
pp. 43-52
The problem of interconnect architecture arises when an array of processors needs to be integrated on one chip. With the deep sub-micron technology, devices become cheap while wires are expensive. On the other hand, high performance systems require the sho...
     
Time critical isosurface refinement and smoothing
Found in: Proceedings of the 2000 IEEE symposium on Volume visualization (VVS '00)
By C. L. Bajaj, V. Pascucci
Issue Date:October 2000
pp. 33-42
From the Coliseum in Rome to the verdant landscape of the Loire Valley, the world's cultural heritage has withstood the text of time. Today though, the pace of progress --- from urban sprawl to pollution, neglect, conflict, and even tourism --- threatens t...
     
Parallel accelerated isocontouring for out-of-core visualization
Found in: Proceedings of the 1999 IEEE symposium on Parallel visualization and graphics (PVGS '99)
By C. L. Bajaj, D. Thompson, V. Pascucci, X. Y. Zhang
Issue Date:October 1999
pp. 97-104
In this paper we introduce a scheme for static analysis that allows us to partition large geometric datasets at multiple levels of granularity to achieve both load balancing in parallel computations and minimal access to secondary memory in out-of-core com...
     
Web based collaborative CAAD
Found in: Proceedings of the fifth ACM symposium on Solid modeling and applications (SMA '99)
By A. Paoluzzi, C. Bajaj, C. Morgia, S. Cutchin, V. Pascucci
Issue Date:June 1999
pp. 326-327
The problem of interconnect architecture arises when an array of processors needs to be integrated on one chip. With the deep sub-micron technology, devices become cheap while wires are expensive. On the other hand, high performance systems require the sho...
     
Hypervolume visualization: a challenge in simplicity
Found in: Proceedings of the 1998 IEEE symposium on Volume visualization (VVS '98)
By C. L. Bajaj, D. Schikorc, G. Rabbiolo, V. Pascucci
Issue Date:October 1998
pp. 95-102
From the Coliseum in Rome to the verdant landscape of the Loire Valley, the world's cultural heritage has withstood the text of time. Today though, the pace of progress --- from urban sprawl to pollution, neglect, conflict, and even tourism --- threatens t...
     
NURBS based B-rep models for macromolecules and their properties
Found in: Proceedings of the fourth ACM symposium on Solid modeling and applications (SMA '97)
By C. Bajaj, H. Y. Lee, R. Merkert, V. Pascucci
Issue Date:May 1997
pp. 217-228
The problem of interconnect architecture arises when an array of processors needs to be integrated on one chip. With the deep sub-micron technology, devices become cheap while wires are expensive. On the other hand, high performance systems require the sho...
     
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