Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Algorithms (8)
- Fortran D (2)
- Logic programming (2)
- Loosely synchronous communication (2)
- MKdV flows (2)
-
- Parallel processing (2)
- Parallelism (2)
- Parallelization (2)
- Personalized communications (2)
- Primality testing (2)
- Processing problems (2)
- Runtime scheduling (2)
- Simulated annealing (2)
- Static scheduling (2)
- Symmetric Unitary One Matrix Models (2)
- Adjacent transposition sorting (1)
- Autocorrelations (1)
- Benchmarking (1)
- Bid/ask spread (1)
- Block structured problems (1)
- C++ (1)
- CM-5 (1)
- Cellular automata (1)
- Chemistry (1)
- Class flattening (1)
- Communication (1)
- Communication patterns (1)
- Comparators (1)
- Computing Surface (1)
- Concurrent programming-distributed programming (1)
- Publication
Articles 1 - 30 of 46
Full-Text Articles in Physical Sciences and Mathematics
Translational Correlations In The Vortex Array At The Surface Of A Type-Ii Superconductor, M. Cristina Marchetti, David R. Nelson
Translational Correlations In The Vortex Array At The Surface Of A Type-Ii Superconductor, M. Cristina Marchetti, David R. Nelson
Physics - All Scholarship
We discuss the statistical mechanics of magnetic flux lines in a finite-thickness slab of type-II superconductor. The long wavelength properties of a flux-line liquid in a slab geometry are described by a hydrodynamic free energy that incorporates the boundary conditions on the flux lines at the sample's surface as a surface contribution to the free energy. Bulk and surface weak disorder are modeled via Gaussian impurity potentials. This free energy is used to evaluate the two-dimensional structure factor of the flux-line tips at the sample surface. We find that surface interaction always dominates in determining the decay of translational correlations …
Non-Relativistic Qcd For Heavy Quark Systems, Simon Catterall, F. R. Devlin, I. T. Drummond, R. R. Horgan, A. D. Simpson
Non-Relativistic Qcd For Heavy Quark Systems, Simon Catterall, F. R. Devlin, I. T. Drummond, R. R. Horgan, A. D. Simpson
Physics - All Scholarship
We employ a nonrelativistic version of QCD (NRQCD) to study heavy quark-antiquark bound states in the lowest approximation without fine structure. We use gluon configurations on a 16^3 by 48 lattice at beta=6.2 from the UKQCD collaboration. For quark masses in the vicinity of the b we obtain bound state masses for S, P and both types of D wave. We also detect signals for two types of hybrids (quark,antiquark,gluon states). The results are sufficiently accurate to confirm that the values of the D wave mass from both lattice D waves coincide indicating that the cubical invariance of the lattice …
Symmetry Breaking In A Generalized Skyrme Model, Joseph Schechter
Symmetry Breaking In A Generalized Skyrme Model, Joseph Schechter
Physics - All Scholarship
We first outline the calculations of the neutron-proton mass difference and of the axial singlet matrix element (relevant to the "proton spin" puzzle) in a generalized Skyrme model of pseudoscalars and vectors. These two calculations are, perhaps surprisingly, linked to each other and furthermore are sensitive to some fine details of symmetry breaking in the effective meson Lagrangian. This provides a motivation for us to examine these symmetry breaking terms more closely. We find a qualitatively new feature in the symmetry breaking pattern of the vector meson system and discuss its significance. (Talk at Workshop on "Baryons as Skyrme Solitons," …
Effective Hadron Dynamics: From Meson Masses To The Proton Spin Puzzle, Joseph Schechter, A Subbaraman, H. Weigel
Effective Hadron Dynamics: From Meson Masses To The Proton Spin Puzzle, Joseph Schechter, A Subbaraman, H. Weigel
Physics - All Scholarship
We construct a three flavor chiral Lagrangian of pseudoscalars and vectors with special emphasis on the symmetry breaking terms. Comparing tree level two and three point functions with experiment allows us to first, fix the parameters of the model (including the light quark mass ratios) and second, to predict m(K^{*+})-m(K^{*\circ}),\, \Gamma(K^*\rightarrow K\pi) and \Gamma(\phi\rightarrow K {\overline K}). The last mentioned quantities come out reasonably well, in contrast to an ``ordinary" SU(3) treatment. For this purpose we need ``second order" symmetry breakers involving the vector fields analogous to those needed for the chiral perturbation theory program with only pseudoscalars. An improved …
Role Of Light Vector Mesons In The Heavy Particle Chiral Lagrangian, Joseph Schechter, A. Subbaraman
Role Of Light Vector Mesons In The Heavy Particle Chiral Lagrangian, Joseph Schechter, A. Subbaraman
Physics - All Scholarship
We give the general framework for adding "light" vector particles to the heavy hadron effective chiral Lagrangian. This has strong motivations both from the phenomenological and aesthetic standpoints. An application to the already observed D \rightarrow \overbar{K^*} weak transition amplitude is discussed
Numerical Solution Of Laplace's Equation, Per Brinch Hansen
Numerical Solution Of Laplace's Equation, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
This tutorial discusses Laplace's equation for steady state heat flow in a two-dimensional region with fixed temperatures on the boundaries. The equilibrium temperatures are computed for a square grid using successive overrelaxation with parity ordering of the grid elements. The numerical method is illustrated by a Pascal algorithm. We assume that the reader is familiar with elementary calculus.
Parallel Cellular Automata: A Model Program For Computational Science, Per Brinch Hansen
Parallel Cellular Automata: A Model Program For Computational Science, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
We develop a model program for parallel execution of cellular automata on a multicomputer. The model program is then adapted for simulation of forest fires and numerical solution of Laplace's equation for stationary heat flow. The performance of the parallel program is analyzed and measured on a Computing Surface configured as a matrix of transputers with distributed memory.
Multiple-Length Division Revisited: A Tour Of The Minefield, Per Brinch Hansen
Multiple-Length Division Revisited: A Tour Of The Minefield, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
Long division of natural numbers plays a crucial role in Cobol arithmetic, cryptography, and primality testing. Only a handful of textbooks discuss the theory and practice of long division, and none of them do it satisfactorily. This tutorial attempts to fill this surprising gap in the literature on computer algorithms. We illustrate the subtleties of long division by examples, define the problem concisely, summarize the theory, and develop a complete Pascal algorithm using a consistent terminology.
All-To-Many Communication Avoiding Node Contention, Sanjay Ranka, Jhy-Chun Wang
All-To-Many Communication Avoiding Node Contention, Sanjay Ranka, Jhy-Chun Wang
Electrical Engineering and Computer Science - Technical Reports
In this paper we present several algorithms for all-too-many personalized communications which avoid node contention.
The Cosmological Kibble Mechanism In The Laboratory: String Formation In Liquid Crystals, Mark Bowick, L. Chandar, Eric A. Schiff, Ajit M. Srivastava
The Cosmological Kibble Mechanism In The Laboratory: String Formation In Liquid Crystals, Mark Bowick, L. Chandar, Eric A. Schiff, Ajit M. Srivastava
Physics - All Scholarship
We have observed the production of strings (disclination lines and loops) via the Kibble mechanism of domain (bubble) formation in the isotropic to nematic phase transition of a sample of uniaxial nematic liquid crystal. The probablity of string formation per bubble is measured to be $0.33 \pm 0.01$. This is in good agreement with the theoretical value $1/ \pi$ expected in two dimensions for the order parameter space $S^2/{\bf Z}_2$ of a simple uniaxial nematic liquid crystal.
Critical Behavior Of Charge Density Waves Below Threshold: Numerical And Scaling Analysis, Alan Middleton, Daniel S. Fisher
Critical Behavior Of Charge Density Waves Below Threshold: Numerical And Scaling Analysis, Alan Middleton, Daniel S. Fisher
Physics - All Scholarship
The critical behavior of pinned charge density waves (CDW's) is studied as the threshold for sliding is approached. Using the Fukuyama-Lee-Rice Hamiltonian with relaxational dynamics, the polarization and linear response are calculated numerically. ... On the irreversible approach to threshold, the response due to avalanches triggered by local instabilities dominates the polarizability, which diverges in one and two dimensions. Characteristic diverging length scales are studied using finite-size scaling of the sample-to-sample variations of the threshold field in finite systems and finite-size effects in the linear polarizability and the irreversible polarization. A dominant diverging correlation length is found which controls the …
Modification Of The Magnetic Flux-Line Interaction At A Superconductor's Surface, M. Cristina Marchetti
Modification Of The Magnetic Flux-Line Interaction At A Superconductor's Surface, M. Cristina Marchetti
Physics - All Scholarship
The pair interaction between magnetic flux lines in a semi-infinite slab of an anisotropic type-II superconductor in an external field is derived in the London limit. The case where the applied field is normal to the superconductor/vacuum interface is considered. The presence of stray fields near the surface leads to an additional contribution to the repulsive interaction between flux lines that vanishes exponentially with the distance from the interface. The pair interaction is used to obtain the continuum elastic energy of a distorted semi-infinite flux-line array. The presence of the superconductor/vacuum interface yields surface contributions to the compressional and tilt …
Numerical Study Of C>1 Matter Coupled To Quantum Gravity, Simon Catterall, John B. Kogut, Ray L. Renken
Numerical Study Of C>1 Matter Coupled To Quantum Gravity, Simon Catterall, John B. Kogut, Ray L. Renken
Physics - All Scholarship
We present the results of a numerical simulation aimed at understanding the nature of the `c = 1 barrier' in two dimensional quantum gravity. We study multiple Ising models living on dynamical \phi^3 graphs and analyse the behaviour of moments of the graph loop distribution. We notice a universality at work as the average properties of typical graphs from the ensemble are determined only by the central charge. We further argue that the qualitative nature of these results can be understood from considering the effect of fluctuations about a mean field solution in the Ising sector.
Quantitative Footprinting Analysis Of The Chromomycin A 3 - D N A Interaction, Allison Stankus, Jerry Goodisman, James C. Dabrowiak
Quantitative Footprinting Analysis Of The Chromomycin A 3 - D N A Interaction, Allison Stankus, Jerry Goodisman, James C. Dabrowiak
Chemistry - All Scholarship
Chromomycin A3 (CHR) binding to the duplex d(CAAGTCTGGCCATCAGTC)- d(GACTGATGGCCAGACTTG) has been studied using quantitative footprinting methods. Previous NMR studies indicated CHR binds as a dimer in the minor groove. Analysis of autoradiographic spot intensities derived from DNase I cleavage of the 18-mer in the presence of various amounts of CHR revealed that the drug binds as a dimer to the sequence 5’-TGGCCA-3’, 3’-ACCGGT-5’ in the 18-mer with a binding constant of (2.7 f 1.4) X lo7 M-l. Footprinting and fluorescence data indicate that the dimerization constant for the drug in solution is -lo5 M-l. Since it has been suggested that …
Self Organization And A Dynamical Transition In Traffic Flow Models, Alan Middleton, Ofer Biham, Dov Levine
Self Organization And A Dynamical Transition In Traffic Flow Models, Alan Middleton, Ofer Biham, Dov Levine
Physics - All Scholarship
A simple model that describes traffic flow in two dimensions is studied. A sharp {\it jamming transition } is found that separates between the low density dynamical phase in which all cars move at maximal speed and the high density jammed phase in which they are all stuck. Self organization effects in both phases are studied and discussed.
Three Dimensional Quantum Gravity Coupled To Ising Matter, Simon Catterall, Ray L. Renken, John B. Kogut
Three Dimensional Quantum Gravity Coupled To Ising Matter, Simon Catterall, Ray L. Renken, John B. Kogut
Physics - All Scholarship
We establish the phase diagram of three--dimensional quantum gravity coupled to Ising matter. We find that in the negative curvature phase of the quantum gravity there is no disordered phase for ferromagnetic Ising matter because the coordination number of the sites diverges. In the positive curvature phase of the quantum gravity there is evidence for two spin phases with a first order transition between them.
Simulated Annealing, Per Brinch Hansen
Simulated Annealing, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
This tutorial describes simulated annealing, an optimization method based on the principles of statistical mechanics. Simulated annealing finds near-optimal solutions to optimization problems that cannot be solved exactly because they are NP-complete. The method is illustrated by a Pascal algorithm for the traveling salesperson problem. The performance of the algorithm was measured on a Computing Surface.
Parallel Monte Carlo Trials, Per Brinch Hansen
Parallel Monte Carlo Trials, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
The best results of Monte Carlo methods are generally obtained by performing the same computation many times with different random numbers. We develop a generic algorithm for parallel execution of Monte Carlo trials on a multicomputer. The generic algorithm has been adapted for simulated annealing and primality testing by simple substitutions of data types and procedures. The performance of the parallel algorithms was measured on a Computing Surface.
Primality Testing, Per Brinch Hansen
Primality Testing, Per Brinch Hansen
Electrical Engineering and Computer Science - Technical Reports
This tutorial describes the Miller-Rabin method for testing the primality of large integers. The method is illustrated by a Pascal algorithm. The performance of the algorithm was measured on a Computing Surface.
Designing Efficient Maximum-Likelihood Soft-Decision Decoding Algorithms For Linear Block Codes Using Algorithm A*, Yunghsiang S. Han, Carlos R.P. Hartmann
Designing Efficient Maximum-Likelihood Soft-Decision Decoding Algorithms For Linear Block Codes Using Algorithm A*, Yunghsiang S. Han, Carlos R.P. Hartmann
Electrical Engineering and Computer Science - Technical Reports
In this report we present a class of efficient maximum-likelihood soft-decision decoding algorithms for linear block codes. The approach used here is to convert the decoding problem into a search problem through a graph which is a trellis for an equivalent code of the transmitted code. Algorithm A*, which uses a priority-first search strategy, is employed to search through this graph. This search is guided by an evaluation function f defined to take advantage of the information provided by the received vector and the inherent properties of the transmitted code. This function f is used to drastically reduce the search …
Thermal Rounding Of The Charge Density Wave Depinning Transition, Alan Middleton
Thermal Rounding Of The Charge Density Wave Depinning Transition, Alan Middleton
Physics - All Scholarship
The rounding of the charge density wave depinning transition by thermal noise is examined. Hops by localized modes over small barriers trigger ``avalanches'', resulting in a creep velocity much larger than that expected from comparing thermal energies with typical barriers. For a field equal to the $T=0$ depinning field, the creep velocity is predicted to have a {\em power-law} dependence on the temperature $T$; numerical computations confirm this result. The predicted order of magnitude of the thermal rounding of the depinning transition is consistent with rounding seen in experiment.
General Model Theoretic Semantics For Higher-Order Horn Logic Programming, Mino Bai, Howard A. Blair
General Model Theoretic Semantics For Higher-Order Horn Logic Programming, Mino Bai, Howard A. Blair
Electrical Engineering and Computer Science - Technical Reports
We introduce model-theoretic semantics [6] for Higher-Order Horn logic programming language. One advantage of logic programs over conventional non-logic programs has been that the least fixpoint is equal to the least model, therefore it is associated to logical consequence and has a meaningful declarative interpretation. In simple theory of types [9] on which Higher-Order Horn logic programming language is based, domain is dependent on interpretation [10]. To define T p operator for a logic program P, we need a fixed domain without regard to interpretation which is usually taken to be a set of atomic propositions. We build a semantics …
Embedding Data Mappers With Distributed Memory Machine Compilers, Ravi Ponnusamy, Joel Saltz, Raja Das, Charles Koelbel, Alok Choudhary
Embedding Data Mappers With Distributed Memory Machine Compilers, Ravi Ponnusamy, Joel Saltz, Raja Das, Charles Koelbel, Alok Choudhary
Electrical Engineering and Computer Science - Technical Reports
In scalable multiprocessor systems, high performance demands that computational load be balanced evenly among processors and that interprocessor communication be limited as much as possible. Compilation techniques for achieving these goals have been explored extensively in recent years [3, 9, 11, 13, 17, 18]. This research has produced a variety of useful techniques, but most of it has assumed that the programmer specifies the distribution of large data structures among processor memories. A few projects have attempted to automatically derive data distributions for regular problems [12, 10, 8, 1]. In this paper, we study the more challenging problem of automatically …
A Probabilistic Analysis Of A Locality Maintaining Load Balancing Algorithm, Kishan Mehrotra, Sanjay Ranka, Jhy-Chun Wang
A Probabilistic Analysis Of A Locality Maintaining Load Balancing Algorithm, Kishan Mehrotra, Sanjay Ranka, Jhy-Chun Wang
Electrical Engineering and Computer Science - Technical Reports
This paper presents a simple load balancing algorithm and its probabilistic analysis. Unlike most of the previous load balancing algorithms, this algorithm maintains locality. We show that the cost of this load balancing algorithm is small for practical situations and discuss some interesting applications for data remapping.
A Non-Deterministric Parallel Sorting Algorithm, Xue Shirley Li, F. Lockwood Morris
A Non-Deterministric Parallel Sorting Algorithm, Xue Shirley Li, F. Lockwood Morris
Electrical Engineering and Computer Science - Technical Reports
A miniswap Si,1 ≤ i < n, compares two adjacent keys Пi, Пi+1 in the sequence (П1, ... , Пn), and transposes them if they are out of order. A full sweep is any composition of all n - 1 possible miniswaps. We prove that the composition of any n- 1 full sweeps is a sorting function.
Conceptual Background For Symbolic Computation, Klaus Berkling
Conceptual Background For Symbolic Computation, Klaus Berkling
Electrical Engineering and Computer Science - Technical Reports
This paper is a tutorial which examines the three major models of computation--the Turing Machine, Combinators, and Lambda Calculus--with respect to their usefulness to practical engineering of computing machines. While the classical von Neumann architecture can be deduced from the Turing Machine model, and Combinator machines have been built on an experimental basis, no serious attempts have been made to construct a Lambda Calculus machine. This paper gives a basic outline of how to incorporate a Lambda Calculus capability into a von Neumann type architecture, maintaining full backward compatibility and at the same time making optimal use of its advantages …
Fault-Detection In Networks, H. F. Mattson Jr
Fault-Detection In Networks, H. F. Mattson Jr
Electrical Engineering and Computer Science - Technical Reports
To find broken links in networks we use the cut-set space. Information on which nodes can talk, or not, to which other nodes allows reduction of the problem to that of decoding the cut-set code of a graph. Special classes of such codes are known to have polynomial-time decoding algorithms. We present a simple algorithm to achieve the reduction and apply it in two examples.
A Declarative Foundation Of Λprolog With Equality, Mino Bai
A Declarative Foundation Of Λprolog With Equality, Mino Bai
Electrical Engineering and Computer Science - Technical Reports
We build general model-theoretic semantics for higher-order logic programming languages. Usual semantics for first-order logic is two-level: i.e., at a lower level we define a domain of individuals, and then, we define satisfaction of formulas with respect to this domain. In a higher-order logic which includes the propositional type in its primitive set of types, the definition of satisfaction of formulas is mutually recursive with the process of evaluation of terms. As result of this in higher-order logic it is extremely difficult to define an effective semantics. For example to define T p operator for logic program P, we need …
Empirical Relations Between Static And Dynamic Exponents For Ising Model Cluster Algorithms, Paul D. Coddington, Clive F. Baillie
Empirical Relations Between Static And Dynamic Exponents For Ising Model Cluster Algorithms, Paul D. Coddington, Clive F. Baillie
Physics - All Scholarship
We have measured the autocorrelations for the Swendsen-Wang and the Wolff cluster update algorithms for the Ising model in 2, 3 and 4 dimensions. The data for the Wolff algorithm suggest that the autocorrelations are linearly related to the specific heat, in which case the dynamic critical exponent zW int,E = α/ν. For the Swendsen-Wang algorithm, scaling the autocorrelations by the average maximum cluster size gives either a constant or a logarithm, which implies that zSW int,E = β/ν for the Ising model.
An Algebraic Approach To The Quantization Of Cosntrained Systems: Finite Dimensional Examples, Ranjeet S. Tate
An Algebraic Approach To The Quantization Of Cosntrained Systems: Finite Dimensional Examples, Ranjeet S. Tate
Physics - All Scholarship
We discuss the statistical mechanics of magnetic flux lines in a finite-thickness slab of type-II superconductor. The long wavelength properties of a flux-line liquid in a slab geometry are described by a hydrodynamic free energy that incorporates the boundary conditions on the flux lines at the sample's surface as a surface contribution to the free energy. Bulk and surface weak disorder are modeled via Gaussian impurity potentials. This free energy is used to evaluate the two-dimensional structure factor of the flux-line tips at the sample surface. We find that surface interaction always dominates in determining the decay of translational correlations …