CAMCOS Drip Accretion banner

Recent publications coming from CAMCOS projects

Here are some recent CAMCOS projects and some scientific publications and talks that have resulted from them.

Optimal clustering in 1-dimensional and higher-dimensional data, Spring 2002-Spring 2003

Dr. Jeff Scargle, an astronomer at NASA-Ames, has long been interested in the problem of taking a region of 1- or 2- (or n-) dimensional space, with selected data points in it, and dividing the region into areas of roughly uniform density. Under the supervision of Dr. Brad Jackson (SJSU Math), from Spring 2002-Spring 2003, student teams working on this project:

  • devised and implemented an efficient yet provably optimal algorithm that solves the 1-dimensional version of the problem;
  • explored different approaches to the 2- (or actually, n-) dimensional problem, and devised an n-dimensional algorithm that is conjectured to be optimal, albeit too slow to solve large problems; and
  • investigated effective and efficient 2-dimensional algorithms for this problem, based on established methods in combinatorial optimization.

Resulting publications and talks:

  • An algorithm for optimal partitioning of data on an interval, Jackson, B.; Scargle, J.D.; Barnes, D.; Arabhi, S.; Alt, A.; Gioumousis, P.; Gwin, E.; Sangtrakulcharoen, P.; Tan, L.; Tun Tao Tsai. (All authors after the first two are CAMCOS students.) IEEE Signal Processing Letters, Vol. 12, No. 2, Feb. 2005, pp. 105-108.
  • Gray Level Reduction for Segmentation, Threshholding, and Binarization of Images Based on Optimal Partitioning on an Interval, Mahmoud Queweider, Brad Jackson, and Jeffrey D. Scargle, submitted.
  • Talk by Jackson at Bay Area Discrete Math Day, UC Berkeley, October 30, 2004. "Algorithms For Finding Optimal Partitions of Astronomical Data."
  • Talk by Scargle at Institute for Pure and Applied Mathematics, UCLA, Multiscale Geometry and Analysis, Workshop IV: Multiscale Geometric Methods in Astronomical Data Analysis, November 8-12, 2004. "Multiscale Data Analysis through Optimal Segmentation."

Statistical analysis of a nonlinear chemical equation using numerical methods, Spring 2002

Dr. Laura Iraci, a chemist at NASA-Ames, investigates the reactions of halogenated gases (HOBr, HBr, HCl) on aqueous sulfuric acid, which is representative of the aerosol particles found in the Earth's atmosphere at high altitudes. Dr. Iraci was interested in measuring the extent to which a certain "unusual" reaction appeared in her experiment. In Spring 2002, a student team supervised by Dr. Steve Crunk used statistical and numerical methods to estimate certain interesting reaction parameters and give 95% confidence intervals for those parameters. In particular, it was determined with 95% confidence that the "unusual" reaction actually occurred in several cases.

Resulting publication:

  • The team's results are used in an appendix to Uptake of hypobromous acid (HOBr) by aqueous sulfuric acid solutions: Low-temperature solubility and reaction, L. T. Iraci, R. R. Michelsen, S. F. M. Ashbourn, T. A. Rammer, and D. M. Golden, submitted to the Journal of Atmospheric Chemistry.

Center for Applied Mathematics, Computation, and Statistics
 Department of Mathematics and Statistics • San Jose State University • One Washington Square • San Jose, CA 95192-0103
fax (408) 942-5080