Development of Efficient Algorithms for the Solutions of Full Potential and Euler Equations on Vector Computers

Author(s):  
R. K. Jain ◽  
N. Kroll ◽  
R. Radespiel
1983 ◽  
Vol 23 (05) ◽  
pp. 743-745 ◽  
Author(s):  
P.T. Woo ◽  
John M. Levesque

Abstract An existing general sparse-elimination algorithm was benchmarked on the Cyber 205 and the Cray 1-S. Computation rates on the Cyber 205 reached 16. 7 million floating point operations per second (MFLOPS) and 9. 8 MFLOPS on the Cray 1-S. It is concluded that the existing algorithm does not exploit the full potential of the vector computer. Several schemes are under investigation to improve the performance of the algorithm. Introduction General-purpose sparse-elimination techniques have been used successfully in solving systems of linear equations in reservoir simulation. These techniques allow Gaussian elimination to be performed efficiently with any given matrix ordering. The implementation of these techniques on a scalar computer such as the IBM 370/158 and on an array processor such as the Floating Point Systems AP120B are described in Refs. 1 and 2. respectively. The purpose of this paper is to report the results of a benchmark test to determine the performance of a known sparse-elimination algorithm on the vector computers Cyber 205 and Cray 1-S. The ground rules for the benchmark were as follows.The sparse-elimination algorithm was to remain unchanged.The use of vectorizable FORTRAN or vector syntax FORTRAN was allowed.The use of assembly-language coding was not allowed unless the assembly-language code was part of a systems or mathematics library callable by FORTRAN.The alternate diagonal grid ordering was to be used. Implementation on the Vector Computer The algorithm NNF in the Yale sparse matrix packages was used for benchmarking. The matrix equation to be solved is A is factored into the lower triangular matrix, L, and the upper triangular matrix, U. The elements of A, L, and U are stored in a compressed storage mode as described by Gustavson. The solution vector x is obtained by forward substitution by using L, and backward substitution by using U. The Yale algorithm uses the row operations approach, which consists of two steps:multiply one equation by a nonzero number, andadd (or subtract) the equation from above to (or from) another equation. Step 2 reduces the nonzeros in the lower triangular portion of A to zeros as factorization proceeds. portion of A to zeros as factorization proceeds. SPEJ P. 743


Author(s):  
R.W. Horne

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.


Author(s):  
Benjamin M. Siegel

The potential advantages of high voltage electron microscopy for extending the limits of resolution and contrast in imaging low contrast objects, such as biomolecular specimens, is very great. The results of computations will be presented showing that at accelerating voltages of 500-1000 kV it should be possible to achieve spacial resolutions of 1 to 1.5 Å and using phase contrast imaging achieve adequate image contrast to observe single atoms of low atomic number.The practical problems associated with the design and utilization of the high voltage instrument are, optimistically, within the range of competence of the state of the art. However, there are some extremely important and critical areas to be systematically investigated before we have achieved this competence. The basic electron optics of the column required is well understood, but before the full potential of an instrument capable of resolutions of better than 1.5 Å are realized some very careful development work will be required. Of great importance for the actual achievement of high resolution with a high voltage electron microscope is the fundamental limitation set by the characteristics of the high voltage electron beam that can be obtained from the accelerator column.


1971 ◽  
Vol 10 (03) ◽  
pp. 245-251 ◽  
Author(s):  
P. Richards ◽  
W. C. Eckelman

SummaryThe full potential use of technetium has not been achieved despite its ideal physical properties, dosimetry and availability because of the complex preparations required for 99mTc radiopharmaceuticals. One of the goals of our work is to develop techniques for the preparation of high-purity 99mTc compounds which can be easily prepared, ideally by adding pertechnetate to a prepared solution.The use of stannous ion as reducing agent for technetium makes it possible to obtain such one-step, high-purity products. All non-radioactive components can be premixed in a single vial before addition of the radioactive pertechnetate. No final pH adjustment, further chemical manipulation or purification is required.Procedures for two instantly labeled compounds have been developed to date: 99mTc DTPA and 99mTc HSA. The 99mTc DTPA is prepared by adding pertechnetate to a previously prepared solution of stannous ion and CaNa3 DTPA which has been stored at pH 4. The 99mTc HSA is prepared by adding pertechnetate to a solution of stannous ion and HSA. The parametric variations and analytical techniques involved in formulating these procedures are described. It appears that development of kits for other biologically interesting compounds may be possible using similar procedures.


1993 ◽  
Vol 32 (04) ◽  
pp. 265-268 ◽  
Author(s):  
D. J. Essin

AbstractLoosely structured documents can capture more relevant information about medical events than is possible using today’s popular databases. In order to realize the full potential of this increased information content, techniques will be required that go beyond the static mapping of stored data into a single, rigid data model. Through intelligent processing, loosely structured documents can become a rich source of detailed data about actual events that can support the wide variety of applications needed to run a health-care organization, document medical care or conduct research. Abstraction and indirection are the means by which dynamic data models and intelligent processing are introduced into database systems. A system designed around loosely structured documents can evolve gracefully while preserving the integrity of the stored data. The ability to identify and locate the information contained within documents offers new opportunities to exchange data that can replace more rigid standards of data interchange.


2016 ◽  
Vol 10 ◽  
pp. 40-47
Author(s):  
Ulla Johansson Sköldberg ◽  
Jill Woodilla

Drawing on data from two projects where artists used their artistic competence as organizational change facilitators, we argue for a theoretical coupling of the discourse(s) of design thinking to research streams within art-and-management. The artistic dimension of design, the practice perspective and the artistic process should be considered if we are to understand the full potential of design thinking for companies. This paper describes two artistic intervention projects that highlight valuable ways artists can contribute to organizational innovation and change.  We begin with the theoretical frame of reference and a short methodological statement, followed by the empirical material.  In the analysis section we point to ways in which such interventions are similar to ones led by designers when we consider the designer’s process as individualized and contextualized.  Finally, we draw conclusions.


2018 ◽  
Vol 12 ◽  
pp. 25-41
Author(s):  
Matthew C. FONTAINE

Among the most interesting problems in competitive programming involve maximum flows. However, efficient algorithms for solving these problems are often difficult for students to understand at an intuitive level. One reason for this difficulty may be a lack of suitable metaphors relating these algorithms to concepts that the students already understand. This paper introduces a novel maximum flow algorithm, Tidal Flow, that is designed to be intuitive to undergraduate andpre-university computer science students.


2004 ◽  
Vol 9 (4) ◽  
pp. 363-372 ◽  
Author(s):  
T. Lukaszewicz ◽  
A. Ravinski ◽  
I. Makoed

A new multilayer electrochromic device has been constructed according to the following pattern: glass1/ITO/WO3/gel electrolyte/BP/ITO/glass2, where ITO is a transparent conducting film made of indium and tin oxide and with the surface resistance equal 8–10 Ω/cm2 . The electrochromic devices obtained in the research are characterized by great (considerable) transmittance variation between coloration and bleaching state (25–40% at applied voltage of 1.5 to 3 V), and also high coloration efficiency (above 100 cm2 /C). Selfconsistent energy bands, dielectric permittivity and optical parameters are calculated using a full-potential linear muffin-tin orbital method. The numerical solution of the Debye-Smoluchowski equations is developed for simulating recombination probability of Li+ ions in amorphous electrolyte.


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