Numerical homogenization on approach for stokesian suspensions.

Numerical homogenization on approach for stokesian suspensions.

Date: January 20, 2012
Creator: Haines, B. M.; Berlyand, L. V.; Karpeev, D. A. (Mathematics and Computer Science) & (Department of Mathematics, Pennsylvania State Univ.)
Description: In this technical report we investigate efficient methods for numerical simulation of active suspensions. The prototypical system is a suspension of swimming bacteria in a Newtonian fluid. Rheological and other macroscopic properties of such suspensions can differ dramatically from the same properties of the suspending fluid alone or of suspensions of similar but inactive particles. Elongated bacteria, such as E. coli or B. subtilis, swim along their principal axis, propelling themselves with the help of flagella, attached at the anterior of the organism and pushing it forward in the manner of a propeller. They interact hydrodynamically with the surrounding fluid and, because of their asymmetrical shape, have the propensity to align with the local flow. This, along with the dipolar nature of bacteria (the two forces a bacterium exerts on a fluid - one due to self-propulsion and the other opposing drag - have equal magnitude and point in opposite directions), causes nearby bacteria to tend to align, resulting in a intermittent local ordering on the mesoscopic scale, which is between the microscopic scale of an individual bacterium and the macroscopic scale of the suspension (e.g., its container). The local ordering is sometimes called a collective mode or collective swimming. ...
Contributing Partner: UNT Libraries Government Documents Department
Numerical and asymptotic studies of complex flow dynamics: Progress report, 12/1/94-12/31/96

Numerical and asymptotic studies of complex flow dynamics: Progress report, 12/1/94-12/31/96

Date: December 31, 1996
Creator: Lorenz, J.
Description: This report summarizes the author`s progress in research and teaching/human resource development during the period December 1, 1994 to December 31, 1996. 9 refs.
Contributing Partner: UNT Libraries Government Documents Department
Mathematics and string theory

Mathematics and string theory

Date: November 25, 2002
Creator: Yau, Shing-Tung
Description: The continuation of the collaboration with Liu and Lian on the calculation of the II A model opened up the possibility to understand calculations for higher genus curves also; many detailed calculations were carried out. They provided evidence that the method is powerful enough to calculate GW invariants in many cases. Local mirror symmetry was worked out with Chiang, Klemm, and Zaslow; it is consistent with physics intuition. Work was carried out to advance the ideas of Stroninger-Yau-Zaslow's geometric version of mirror symmetry in terms of special Lagragian torus fibration. Several papers were written on understanding such duality; it fits well with the predictions, and the ideas are still being studied.
Contributing Partner: UNT Libraries Government Documents Department
Nursery Cultural Practices and Morphological Attributes of Longleaf Pine Bare-Root Stock as Indicators of Early Field Performance

Nursery Cultural Practices and Morphological Attributes of Longleaf Pine Bare-Root Stock as Indicators of Early Field Performance

Date: February 1990
Creator: Hatchell, Glyndon E. & Muse, H. David
Description: A large study of morphological attributes of longleaf pine nursery stock at the Savannah River site of the various attributes measured, only number of lateral roots and seedling diameters were related to performance. Lateral root pruning in the nursery also improved performance. Both survival and growth during the first two years were strongly correlated with larger stem diameter and larger root system development.
Contributing Partner: UNT Libraries Government Documents Department
Hyper-fast interstellar travel via a modification of spacetime geometry

Hyper-fast interstellar travel via a modification of spacetime geometry

Date: August 1, 1997
Creator: Kheyfets, A. & Miller, W.A.
Description: We analyze difficulties with proposals for hyper-fast interstellar travel via modifying the spacetime geometry, using as illustrations the Alcubierre warp drive and the Krasnikov tube. As it is easy to see, no violations of local causality or any other known physical principles are involved as far as motion of spacecrafts is concerned. However, the generation and support of the appropriate spacetime geometry configurations does create problems, the most significant of which are a violation of the weak energy condition, a violation of local causality, and a violation of the global causality protection. The violation of the chronology protection is the most serious of them as it opens a possibility of time travel. We trace the origin of the difficulties to the classical nature of the gravity field. This strongly indicates that hyper-fast interstellar travel should be transferred to the realm of a fully quantized gravitational theory. We outline an approach to further the research in this direction.
Contributing Partner: UNT Libraries Government Documents Department
Phil Wallace and Theoretical Physics at McGill in the 1950's: A Personal Perspective

Phil Wallace and Theoretical Physics at McGill in the 1950's: A Personal Perspective

Date: November 18, 2010
Creator: Jackson, John David
Description: In 1946 Philip (Phil) Russell Wallace joined the Mathematics Department of McGill University as an Associate Professor of Applied Mathematics, apparently because A. H. S. Gillson, Dean of Arts and Science, wanted theoretical physicists to be in the Mathematics Department. He came with the dream of creating a theoretical physics group at McGill. By the spring of 1949, Phil was authorized to recruit two junior faculty in Mathematics. He hired Theodore (Ted) F. Morris from U. Toronto, who joined in September 1949, and me, who came in January 1950. The group had begun. Phil Wallace was born in Toronto in 1915 and grew up there. He entered the University of Toronto in 1933, earned a B.A. in mathematics in 1937, a M.A. in 1938, and a Ph.D. in applied mathematics in 1940 under Leopold Infeld. His Ph.D. thesis in general relativity was entitled 'On the relativistic equations of motion in electromagnetic theory.' In 1940 World War II had engulfed Europe and was having its effect on Canada, but the US was still at peace. L. J. Synge, Head of the Applied Mathematics Department at Toronto, told Wallace that people such as he would be needed in war work, but things ...
Contributing Partner: UNT Libraries Government Documents Department
Final Report for DOE Grant DE-FG02-03ER25579; Development of High-Order Accurate Interface Tracking Algorithms and Improved Constitutive Models for Problems in Continuum Mechanics with Applications to Jetting

Final Report for DOE Grant DE-FG02-03ER25579; Development of High-Order Accurate Interface Tracking Algorithms and Improved Constitutive Models for Problems in Continuum Mechanics with Applications to Jetting

Date: October 14, 2012
Creator: Puckett, Elbridge Gerry & Miller, Gregory Hale
Description: Much of the work conducted under the auspices of DE-FG02-03ER25579 was characterized by an exceptionally close collaboration with researchers at the Lawrence Berkeley National Laboratory (LBNL). For example, Andy Nonaka, one of Professor Miller's graduate students in the Department of Applied Science at U. C. Davis (UCD) wrote his PhD thesis in an area of interest to researchers in the Applied Numerical Algorithms Group (ANAG), which is a part of the National Energy Research Supercomputer Center (NERSC) at LBNL. Dr. Nonaka collaborated closely with these researchers and subsequently published the results of this collaboration jointly with them, one article in a peer reviewed journal article and one paper in the proceedings of a conference. Dr. Nonaka is now a research scientist in the Center for Computational Sciences and Engineering (CCSE), which is also part of the National Energy Research Supercomputer Center (NERSC) at LBNL. This collaboration with researchers at LBNL also included having one of Professor Puckett's graduate students in the Graduate Group in Applied Mathematics (GGAM) at UCD, Sarah Williams, spend the summer working with Dr. Ann Almgren, who is a staff scientist in CCSE. As a result of this visit Sarah decided work on a problem suggested by ...
Contributing Partner: UNT Libraries Government Documents Department
The future of mathematical communication. Final technical report

The future of mathematical communication. Final technical report

Date: December 31, 1994
Creator: Christy, J.
Description: One of the first fruits of cooperation with LBL was the use of the MBone (Multi-Cast Backbone) to broadcast the Conference on the Future of Mathematical Communication, held at MSRI November 30--December 3, 1994. Late last fall, MSRI brought together more than 150 mathematicians, librarians, software developers, representatives of scholarly societies, and both commercial and not-for-profit publishers to discuss the revolution in scholarly communication brought about by digital technology. The conference was funded by the Department of Energy, the National Science Foundation, and the Paul and Gabriella Rosenbaum Foundation. It focused on the impact of the technological revolution on mathematics, but necessarily included issues of a much wider scope. There were talks on electronic publishing, collaboration across the Internet, economic and intellectual property issues, and various new technologies which promise to carry the revolution forward. There were panel discussions of electronic documents in mathematics, the unique nature of electronic journals, technological tools, and the role of scholarly societies. There were focus groups on Developing Countries, K-12 Education, Libraries, and Te{sub X}. The meeting also embodied the promises of the revolution; it was multicast over the MBone channel of the Internet to hundreds of sites around the world and much information ...
Contributing Partner: UNT Libraries Government Documents Department
[Memorandum from Jean Schaake, July 17, 1987]

[Memorandum from Jean Schaake, July 17, 1987]

Date: July 17, 1987
Creator: Schaake, Jean
Description: Memorandum from Jean Schaake to Alan Moore, John Ed Allen, Gerry O'Donovan, Rogers Redding, Walter Sandefur, Bob Stevens, Le Theriot, Blake Dehart, and Ron Arrington, advising them to leave September 15, 1987 open on their calendars, as they are expecting a visit from Julian C. Stanley.
Contributing Partner: Texas Academy of Mathematics and Science
Workshop on Women of Applied Mathematics: Research and Leadership

Workshop on Women of Applied Mathematics: Research and Leadership

Date: September 28, 2004
Creator: O'Leary, Dianne P. & Kolda, Tamara G.
Description: We held a two and a half day workshop on Women of Applied Mathematics: Research and Leadership at the University of Maryland in College Park, Maryland, October 8--10, 2003. The workshop provided a technical and professional forum for eleven senior women and twenty-four early-career women in applied mathematics. Each participant committed to an outreach activity and publication of a report on the workshop's web site. The final session of the workshop produced recommendations for future action.
Contributing Partner: UNT Libraries Government Documents Department
[Memorandum from Tom Preston, May 4, 1987]

[Memorandum from Tom Preston, May 4, 1987]

Date: May 4, 1987
Creator: Preston, Tom
Description: Letter from Tom Preston to John Ed Allen, Frank Kemerer, Gerry O'Donovan, Rogers Redding, Walter Sandefur, Bob Stevens, Le Theriot, and Jean Schaake, on May 4, 1987, asking them to serve on a committee for implementing the curriculum of the Texas Academy of Math and Science.
Contributing Partner: Texas Academy of Mathematics and Science
[Memorandum from Tom Preston, May 4, 1987]

[Memorandum from Tom Preston, May 4, 1987]

Date: May 4, 1987
Creator: Preston, Tom
Description: Memorandum from Tom Preston to John Ed Allen, Frank Kemerer, Gerry O'Donovan, Rogers Redding, Walter Sandefur, Bob Stevens, Le Theriot, and Jean Schaake, on May 4, 1987, asking that they serve on a curriculum committee to implement the Texas Academy of Mathematics and Science.
Contributing Partner: Texas Academy of Mathematics and Science
The workshop on iterative methods for large scale nonlinear problems

The workshop on iterative methods for large scale nonlinear problems

Date: December 1, 1995
Creator: Walker, H.F. & Pernice, M.
Description: The aim of the workshop was to bring together researchers working on large scale applications with numerical specialists of various kinds. Applications that were addressed included reactive flows (combustion and other chemically reacting flows, tokamak modeling), porous media flows, cardiac modeling, chemical vapor deposition, image restoration, macromolecular modeling, and population dynamics. Numerical areas included Newton iterative (truncated Newton) methods, Krylov subspace methods, domain decomposition and other preconditioning methods, large scale optimization and optimal control, and parallel implementations and software. This report offers a brief summary of workshop activities and information about the participants. Interested readers are encouraged to look into an online proceedings available at http://www.usi.utah.edu/logan.proceedings. In this, the material offered here is augmented with hypertext abstracts that include links to locations such as speakers` home pages, PostScript copies of talks and papers, cross-references to related talks, and other information about topics addresses at the workshop.
Contributing Partner: UNT Libraries Government Documents Department
Parent's Education and Children's Test Scores

Parent's Education and Children's Test Scores

Date: April 19, 2012
Creator: Jennings, Garrett & Verrill, Diane
Description: Poster presentation for the 2012 University Scholars Day at the University of North Texas discussing research on correlations between parent's education and children's test scores.
Contributing Partner: UNT Honors College
Least-cost groundwater remediation design using uncertain hydrogeological information. 1998 annual progress report

Least-cost groundwater remediation design using uncertain hydrogeological information. 1998 annual progress report

Date: June 1, 1998
Creator: Pinder, G.F.
Description: 'The objective of the project is to formulate, test, and evaluate a new approach to the least-cost design of groundwater contamination containment and decontamination systems. The proposed methodology employs robust optimization, the outer-approximation method of non-linear programming, and groundwater flow and transport modeling to find the most cost-effective pump-and-treat design possible given the physical parameters describing the groundwater reservoir are known with uncertainty. The result is a methodology that will provide the least-cost groundwater remediation design possible given a specified set of design objectives and physical and sociological constraints. As of the end of the first year of this 3-year project the author has developed and tested the concept of robust optimization within the framework of least-cost groundwater-contamination-containment design. The outer-approximation method has been employed in this context for the relatively simple linear-constraint case associated with the containment problem. In an effort to enhance the efficiency and applicability of this methodology, a new strategy for selecting the various realizations arising out of the Monte-Carlo underpinnings of the robust-optimization technique has been developed and tested. Based upon observations arising out of this work a yet more promising approach has been discovered. The theoretical foundation for this most recent approach has been, ...
Contributing Partner: UNT Libraries Government Documents Department
Final Report: Towards Optimal Petascale Simulations (TOPS), ER25785

Final Report: Towards Optimal Petascale Simulations (TOPS), ER25785

Date: April 15, 2011
Creator: Reynolds, Daniel R.
Description: Multiscale, multirate scientific and engineering applications in the SciDAC portfolio possess resolution requirements that are practically inexhaustible and demand execution on the highest-capability computers available, which will soon reach the petascale. While the variety of applications is enormous, their needs for mathematical software infrastructure are surprisingly coincident; moreover the chief bottleneck is often the solver. At their current scalability limits, many applications spend a vast majority of their operations in solvers, due to solver algorithmic complexity that is superlinear in the problem size, whereas other phases scale linearly. Furthermore, the solver may be the phase of the simulation with the poorest parallel scalability, due to intrinsic global dependencies. This project brings together the providers of some of the world’s most widely distributed, freely available, scalable solver software and focuses them on relieving this bottleneck for many specific applications within SciDAC, which are representative of many others outside. Solver software directly supported under TOPS includes: hypre, PETSc, SUNDIALS, SuperLU, TAO, and Trilinos. Transparent access is also provided to other solver software through the TOPS interface. The primary goals of TOPS are the development, testing, and dissemination of solver software, especially for systems governed by PDEs. Upon discretization, these systems possess mathematical ...
Contributing Partner: UNT Libraries Government Documents Department
[Memorandum from Jean Schaake, September 24, 1987]

[Memorandum from Jean Schaake, September 24, 1987]

Date: September 24, 1987
Creator: Schaake, Jean
Description: Memorandum from Jean Schaake to Alan Moore, John Ed Allen, Gerry O'Donovan, Walter Sandefur, Bob Stevens, Bill Deering, Le Theriot, Blake Dehart, Ron Arrington, Patti Gilbert, and Peggy Guthrie, on September 24, 1987, regarding their next meeting. Schaake asks that they come to the meeting with ideas on nomination and selection criteria, math level testing, computer science, enrichment activities, and a speaker program. A paper concerning the nomination and selection of students is included.
Contributing Partner: Texas Academy of Mathematics and Science
Mentoring for minorities in mathematics and science. Final report

Mentoring for minorities in mathematics and science. Final report

Date: May 1998
Creator: Shamma, S. E.
Description: The University of West Florida received a grant from the US Department of Energy to initiate a program on mentoring for Minorities in Mathematics and Science. The purpose of the program was to develop interest of minority freshman and sophomore students in teaching mathematics and science and then have these students act as role models for grade school students, especially for minorities who are experiencing difficulties in science and mathematics education. Fifteen students, one more than what was budgeted, participated in the project.
Contributing Partner: UNT Libraries Government Documents Department
Singular and nonlinear processes in applied mathematics. Final technical report

Singular and nonlinear processes in applied mathematics. Final technical report

Date: August 5, 1998
Creator: Tabor, M.
Description: A wide range of research topics were supported under this grant. These included: (1) complex space time singularities in nonlinear differential equations; (2) singularities in magneto-hydrodynamics; (3) the dynamics of knots and curves; and (4) the structure and dynamics of foams and grain boundaries. A brief summary of results achieved in each of these four areas is given below along with the associated publications acknowledging DOE support.
Contributing Partner: UNT Libraries Government Documents Department
FINAL REPORT (MILESTONE DATE 9/30/11) FOR SUBCONTRACT NO. B594099 NUMERICAL METHODS FOR LARGE-SCALE DATA FACTORIZATION

FINAL REPORT (MILESTONE DATE 9/30/11) FOR SUBCONTRACT NO. B594099 NUMERICAL METHODS FOR LARGE-SCALE DATA FACTORIZATION

Date: October 18, 2011
Creator: De Sterck, H
Description: The following work has been performed by PI Hans De Sterck and graduate student Manda Winlaw for the required tasks 1-5 (as listed in the Statement of Work). Graduate student Manda Winlaw has visited LLNL January 31-March 11, 2011 and May 23-August 19, 2010, working with Van Henson and Mike O'Hara on non-negative matrix factorizations (NMF). She has investigated the dense subgraph clustering algorithm from 'Finding Dense Subgraphs for Sparse Undirected, Directed, and Bipartite Graphs' by Chen and Saad, testing this method on several term-document matrices and adapting it to cluster based on the rank of the subgraphs instead of the density. Manda Winlaw was awarded a first prize in the annual LLNL summer student poster competition for a poster on her NMF research. PI Hans De Sterck has developed a new adaptive algebraic multigrid algorithm for computing a few dominant or minimal singular triplets of sparse rectangular matrices. This work builds on adaptive algebraic multigrid methods that were further developed by the PI and collaborators (including Sanders and Henson) for Markov chains. The method also combines and extends existing multigrid algorithms for the symmetric eigenproblem. The PI has visited LLNL February 22-25, 2011, and has given a CASC seminar ...
Contributing Partner: UNT Libraries Government Documents Department
Third International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing (MCQMC98)

Third International Conference on Monte Carlo and Quasi-Monte Carlo Methods in Scientific Computing (MCQMC98)

Date: March 2, 1999
Creator: Spanier, Jerome
Description: No abstract prepared.
Contributing Partner: UNT Libraries Government Documents Department
Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport (Partnerships in Computational Science)

Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport (Partnerships in Computational Science)

Date: December 1, 1997
Creator: Sharpley, Robert C.
Description: The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the University of South Carolina component of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997. Seven institutions were primarily involved in this project: Brookhaven National Laboratory, Oak Ridge National Laboratory, Princeton University, SUNY at Stony Brook, Texas A&M University, The University of South Carolina, and the University of Texas at Austin, with contributing efforts from the Westinghouse Savannah River Technology Center. Each institution had primary responsibility for specific research components, but strong collaboration among all institutions was essential for the success of the project and in producing the final deliverables. PICS deliverables include source code for the suite of research simulators and ...
Contributing Partner: UNT Libraries Government Documents Department
Experimental and Numerical Investigation of Flows in Expanding Channels

Experimental and Numerical Investigation of Flows in Expanding Channels

Date: October 28, 2004
Creator: Vorobieff, Vakhtang Putkaradze Peter
Description: This is the first year progress report for our grant starting Feb. 1 2004. It describes experimental and theoretical achievements during the first year, lists the articles published during this period, as well as the progress of the graduate students supported by this grant. The timeline for the future is outlined; the current results convince us that the work will be done on time and within the budget.
Contributing Partner: UNT Libraries Government Documents Department
Equilibrium fluid interface behavior under low- and zero-gravity conditions. II

Equilibrium fluid interface behavior under low- and zero-gravity conditions. II

Date: May 1, 1996
Creator: Concus, P. & Finn, R.
Description: We describe here recent mathematical results that form the basis of our forthcoming space experiment, developed jointly with Mark Weislogel of NASA Lewis Research Center, which is scheduled for the Glovebox on the Mir 23 / NASA 4 Mission in December 1996. The mathematical basis for the Angular Liquid Bridge is described. The anticipated liquid behavior used in the apparatus is illustrated.
Contributing Partner: UNT Libraries Government Documents Department
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