53 T he Jan.–Mar. 1998 IEEE Computational Science & Engineering presented two articles on the Department of Energy's Accelerated Scientific Computing Initiative, from two respected authors. John Gustafson from Ames Lab at Iowa State University discussed ASCI's computational problems. 1 Alex Larzelere, the past Director for Strategic Computing and Modeling for Department of Energy Defense Progra...

This paper unifies the representations of different kinds of computer arithmetic. It is motivated by ideas developed in the book The End of Error by John Gustafson [5]. Here interval arithmetic just deals with connected sets of real numbers. These can be closed, open, half-open, bounded or unbounded. The first chapter gives a brief informal review of computer arithmetic from early floating-poin...

R. A. Burnstein, A. Chakravorty, A. Chan, Y. C. Chen, W. S. Choong, K. Clark, T. Diehl, E. C. Dukes, C. Durandet, J. Duryea, J. Felix, G. Gidal, G. Guglielmo, H. R. Gustafson, K. Heller, C. Ho, P. M. Ho, T. Holmstrom, M. Huang, C. James, M. Jenkins, K. Johns, T. Jones, D. M. Kaplan, L. M. Lederman, N. Leros, F. Lopez, M. J. Longo, L. Lu, W. Luebke, K. Nelson, H. K. Park, J. P. Perroud, D. Rajar...

This work proposes how to generate a set of fuzzy rules from a data set using a clustering algorithm, the GKPFCM. If we recommend a number of clusters, the GKPFCM identifies the location and the approximate shape of each cluster. These ones describe the relations among the variables of the data set, and they can be expressed as conditional rules such as "If/Then". The GKPFCM provides membership...

We suggest an approximation for the zero-balanced Appell hyper-geometric function F 1 near the singular point (1, 1). Our approximation can be viewed as a generalization of Ramanujan's approximation for zero-balanced 2 F 1 and is expressed in terms of 3 F 2. We find an error bound and prove some basic properties of the suggested approximation which reproduce the similar properties of the Appell...

Introduction: When G is a finite group, we may endow G×G with the structure of a probability space by assigning the uniform distribution. As was pointed out by W.H. Gustafson [10], the probability that a randomly chosen pair of elements of G commute is then k(G) |G| , where k(G) is the number of conjugacy classes of G. We denote this probability by cp(G). It was also noted in [10] that cp(G) ≤ ...

Observations of intact yeast cells with the electron microscope have yielded little information on cellular structure because of the impenetrability of the cells to the electron beam. The development of techniques for the preparation of ultra-thin sections promises to obviate this difficulty, and several papers have already appeared in which this approach has been applied in studies of the stru...

The universal scalability law (USL) of computational capacity is a rational function Cp = P (p)/Q(p) with P (p) a linear polynomial and Q(p) a second-degree polynomial in the number of physical processors p, that has been long used for statistical modeling and prediction of computer system performance. We prove that Cp is equivalent to the synchronous throughput bound for a machine-repairman wi...

Working group: A. Ballestrero, S. Banerjee, A. Blondel, M. Campanelli, F. Cavallari, D. G. Charlton, H. S. Chen, D. v. Dierendonck, A. Gaidot, Ll. Garrido, D. Gelé, M. W. Grünewald, G. Gustafson, C. Hartmann, F. Jegerlehner, A. Juste, S. Katsanevas, V. A. Khoze, N. J. Kjær, L. Lönnblad, E. Maina, M. Martinez, R. Møller, G. J. van Oldenborgh, J. P. Pansart, P. Perez, P. B. Renton, T. Riemann, M....

We consider the nonlinear Schrödinger equations i∂tψ = H0ψ + λ|ψ|ψ in R× [0,∞) where H0 = −∆ +V and λ = ±1. Assume that the potential V is radial and decays sufficiently fast at infinity. Assume also that the linear Hamiltonian H0 has only two discrete eigenvalues e0 < e1 < 0 where e0 is simple and e1 has multiplicities 3. We show that there exist three branches of nonlinear excited states and ...