U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Javier Bernal (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 56

Partial Elastic Shape Registration of 3D Surfaces using Dynamic Programming

November 3, 2023
Author(s)
Javier Bernal, James F. Lawrence
The computation of the elastic shape registration of two simple surfaces in 3−dimensional space and therefore of the elastic shape distance between them has been investigated by Kurtek, Jermyn, et al. who have proposed algorithms to carry out this

On Computing Elastic Shape Distances between Curves in d-dimensional Space

June 21, 2021
Author(s)
Javier Bernal, James F. Lawrence, Gunay Dogan, Robert Hagwood
The computation of the elastic registration of two simple curves in higher dimensions and therefore of the elastic shape distance between them has been investigated by Srivastava et al. Assuming the first curve has one or more starting points, and the

Characterization and Computation of Matrices of Maximal Trace over Rotations

October 19, 2019
Author(s)
Javier Bernal, James F. Lawrence
The constrained orthogonal Procrustes problem is the least-squares problem that calls for a rotation matrix that optimally aligns two corresponding sets of points in d-dimensional Euclidean space. This problem generalizes to the so-called Wahba's problem

A Purely Algebraic Justification of the Kabsch-Umeyama Algorithm

October 9, 2019
Author(s)
James F. Lawrence, Javier Bernal, Christoph J. Witzgall
The constrained orthogonal Procrustes problem is the least-squares problem that calls for a rotation matrix that optimally aligns two matrices of the same order. Over past decades, the algorithm of choice for solving this problem has been the Kabsch

Shape Analysis, Lebesgue Integration and Absolute Continuity Connections

July 10, 2018
Author(s)
Javier Bernal
As shape analysis of the form presented in Srivastava and Klassen’s textbook “Functional and Shape Data Analysis” is intricately related to Lebesgue integration and absolute continuity, it is advantageous to have a good grasp of the latter two notions

Fast Dynamic Programming for Elastic Registration of Curves

June 30, 2016
Author(s)
Javier Bernal, Gunay Dogan, Robert Hagwood
Curve registration problems in data analysis and com- puter vision can often be reduced to the problem of match- ing two functions defined on an interval. Dynamic Pro- gramming (DP) is an effective approach to solve this prob- lem. In this paper, we

FFT-based Alignment of 2d Closed Curves with Application to Elastic Shape Analysis

September 10, 2015
Author(s)
Gunay Dogan, Javier Bernal, Robert Hagwood
For many shape analysis problems in computer vision and scientific imaging (e.g., computational anatomy, morphological cytometry), the ability to align two closed curves in the plane is crucial. In this paper, we concentrate on rigidly aligning pairs of

A Fast Algorithm for Elastic Shape Distances Between Closed Planar Curves

June 8, 2015
Author(s)
Gunay Dogan, Javier Bernal, Robert C. Hagwood
Effective computational tools for shape analysis are needed in many areas of science and engineering. We address this and propose a fast algorithm to compute the geodesic distance between elastic closed curves in the plane. The original algorithm for the

Testing Equality of Cell Populations Based on Shape and Geodesic Distance

December 3, 2013
Author(s)
Robert C. Hagwood, Javier Bernal, Michael W. Halter, John T. Elliott
Image cytometry has emerged as a valuable in-vitro screening tool and advances in automated microscopy have made it possible to readily analyze large cellular populations of image data. A statistical procedure to study homogeneity of such data is addressed

Evaluation of Segmentation Algorithms on Cell Populations Using CDF Curves

February 24, 2012
Author(s)
Robert C. Hagwood, Javier Bernal, Michael W. Halter, John T. Elliott
Cell segmentation is a critical step in the analysis pipeline for most imaging cytometry experiments and the segmentation algorithm can effect the quantitative data derived from image analysis. Methods to evaluate segmentation algorithms are important for

Comparison of segmentation algorithms for fluorescence microscopy images of cells

June 14, 2011
Author(s)
Alden A. Dima, John T. Elliott, James J. Filliben, Michael W. Halter, Adele P. Peskin, Javier Bernal, Marcin Kociolek, Mary C. Brady, Hai C. Tang, Anne L. Plant
Segmentation results from nine different segmentation techniques applied to two different cell lines and five different sets of imaging conditions were compared. Significant variability in the results of segmentation was observed that was due solely to

Linking Canny Edge Pixels with Pseudo-watershed Lines

March 1, 2010
Author(s)
Javier Bernal
A method is presented for computing pseudo-watershed lines that can be used for linking pixels that have been identified as edge pixels with the Canny edge detector. An additional procedure is also described for filling breaks that may still exist between

Synthetic Lung Tumor Data Sets for Comparison of Volumetric Algorithms

July 13, 2009
Author(s)
Adele P. Peskin, Alden A. Dima, Javier Bernal, David E. Gilsinn, Karen Kafadar
The change in pulmonary nodules over time is an important indicator of malignant tumors. It is therefore important to be able to measure change in the size of tumors from computed tomography (CT) data taken at different times and on potentially different

AGGRES: A Program for Computing Power Crusts of Aggregates

April 3, 2006
Author(s)
Javier Bernal
AGGRES, a Fortran 77 program for computing a power crust of an aggregate, is discussed. AGGRES takes a finite set of points from the surface of an aggregate, i.e. a three-dimensional object with no holes that contains its center of mass in its interior

Integer Representation of Decimal Numbers for Exact Computations

March 31, 2006
Author(s)
Javier Bernal, Christoph J. Witzgall
A scheme is presented and software is documented for representing as integers input decimal numbers that have been stored in a computer as double precision floating point numbers and for carrying out multiplications, additions and subtractions based on

A Numerical Method for Mass Spectral Data Analysis

January 31, 2005
Author(s)
Anthony J. Kearsley, William E. Wallace, Javier Bernal, Charles M. Guttman
The new generation of mass spectrometers produces an astonishing amount of high-quality data in a brief period of time leading to inevitable data analysis bottlenecks. Automated data analysis algorithms are required for rapid and repeatable processing of

Integer representation of decimal numbers for exact computations

October 1, 2004
Author(s)
Javier Bernal, Christoph J. Witzgall
A scheme is presented and software is documented for representing as integers input decimal numbers that have been stored in a computer as double precision floating point numbers and for carrying out multiplications, additions and subtractions based on