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AbstractAbstract
[en] A method of evaluating experimental data yielding information on atomic masses is described. A prediction of values for atomic masses is given for which there is no direct information or for which the information is insufficient. The experimental data used are reaction energies and mass doublets
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15 Feb 1978; 91 p; 67 refs., 24 figs., 14 tables.; Proefschrift (Dr.).
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Miscellaneous
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Thesis/Dissertation
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[en] A more careful count of the operations involved in solving the linear system associated with collocation of a two-point boundary value problem using a rough splines reverses results recently reported by others in this journal. In addition, it is observed that the use of the technique of ''condensation of parameters'' can decrease the computer storage required. Furthermore, the use of a particular highly localized basis can also reduce the setup time when the mesh is irregular. Finally, operation counts are roughly estimated for the solution of certain linear system associated with two competing collocation methods; namely, collocation with smooth splines and collocation of the equivalent first order system with continuous piecewise polynomials
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Journal Article
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Mathematics of Computation; v. 31(140); p. 916-921
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AbstractAbstract
No abstract available
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Journal Article
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J. Math. Phys. (N.Y.); v. 14(8); p. 1037-1048
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Filges, D.
Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Reaktorentwicklung; Technische Hochschule Aachen (Germany, F.R.)
Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Reaktorentwicklung; Technische Hochschule Aachen (Germany, F.R.)
AbstractAbstract
[en] Different procedures for approximation and interpolation by using natural splines are studied and their applicability in analysis and curve fitting in experiments on reactor physics are shown. Using the definition of the natural spline function and its representation by B-splines in the first part of this seport solutions of data fitting by a Lagrange variational problem and by least square approximation are derived. The numerical problems arising from the solution of the linear systems of equations by fitting experimental data are well conditioned. In the second part the applications of fitting procedures are demonstrated. The analysis of dynamic transit reactivity measurements of simulated THTR pebbles in a critical facility are shown. The fissile content of the pebbles can be determined with minimum reproducibility. Calculations of photopeak parameters of Gamma-spectra and the evaluation of physical reactor parameters from noise measurements, e.g. of the prompt decay constant, give good results using the spline fitting methods. (orig.)
[de]
Verschiedene Approximations- bzw. Interpolationsverfahren mit der natuerlichen Spline-Funktion werden untersucht und ihre Anwendung zur Analyse und Interpretation von reaktorphysikalischen Experimenten dargestellt. Dabei wird im ersten Teil der Arbeit ausgehend von der Definition der natuerlichen Spline-Funktion im Zusammenhang mit der Darstellung durch B-Splines die Loesung von Minimal- bzw. Ausgleichsproblemen durch Splines herausgearbeitet, wobei Loesungen des Lagrange-Variationsproblems und die least squares Approximation abgeleitet werden. Gute Konditionierung der Verfahren zur Anwendung von Messdaten wird erreicht. Im zweiten Teil der Arbeit wird die Anwendung der Verfahren an Experimenten gezeigt. Hierbei wird die Auswertung der Messung dynamischer Probenbeeinflussfunktionen von simulierten THTR-Brennelementen zur Bestimmung des Spaltstoffgehaltes eines kugelfoermigen Brennelementes mit moeglichst kleinem Reproduzierbarkeitsfehler bei Nulleistung einer kritischen Anlage demonstriert. Untersuchungen ueber die Anwendung von Spline-Funktion zur Bestimmung von Photopeak-Parametern aus Gamma-Spektren und zur Auswertung von Korrelationsexperimenten schliessen sich an. (orig.)Original Title
Ein Beitrag zur Interpretation von reaktorphysikalischen Experimenten mit Hilfe von Spline-Funktionen
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Dec 1977; 113 p; 60 figs.; 33 tabs.; 46 refs.; Diss.
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Report
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Thesis/Dissertation
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Kisel', I.V.; Konotopskaya, E.V.; Ososkov, G.A.; Chernov, N.I.
Joint Inst. for Nuclear Research, Dubna (USSR). Lab. of Computing Techniques and Automation
Joint Inst. for Nuclear Research, Dubna (USSR). Lab. of Computing Techniques and Automation
AbstractAbstract
[en] Applicability of the Crawford's method of circle fitting is investigated. Analytical expressions for the dependence of residuals and relative errors on radii fitted were evaluated in assumptions applicable to many physical facilities. The validity of these assumptions was examined by a numerical experiment carried out on the base of parameters of the ARES detector. 6 refs.; 4 figs
Original Title
Issledovanie granits primenimosti metoda Krauforda podgonki okruzhnosti
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1991; 12 p
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Edberg, E.
European Organization for Nuclear Research, Geneva (Switzerland)
European Organization for Nuclear Research, Geneva (Switzerland)
AbstractAbstract
[en] These lectures present appropriate numerical methods for the solution of systems of linear equations, linear least-squares problems, and matrix eigenvalue problems. Particular emphasis is given to the way in which the special properties of the problem and the choice of method may affect the size of the errors. The chapter on linear systems deals mainly with elimination methods. For the linear least-squares problem, the transformation of matrices to upper triangular form by Householder transformations is discussed, and the singular value decomposition and the Moore-Penrose generalized inverse are introduced. The QR method and inverse iteration are presented for the eigenvalue problem Ax=lambdax. The treatment is kept at a level suitable for non-specialists. (Auth.)
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13 Dec 1976; 51 p; Lectures given in the Academic Training Programme of CERN 1975-1976.
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Mughabghab, S.F.
Summary report of the 2. research co-ordination meeting on compilation and evaluation of photonuclear data for applications
Summary report of the 2. research co-ordination meeting on compilation and evaluation of photonuclear data for applications
AbstractAbstract
[en] To obtain reliable estimates of the average level spacings, and correct for unobserved resonances or weak resonances with no spin assignments, the Porter-Thomas and Dyson-Mehta statistics were used
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Source
Oblozinsky, P. (International Atomic Energy Agency, Vienna (Austria). Nuclear Data Section); International Atomic Energy Agency, Vienna (Austria). International Nuclear Data Committee; 53 p; Sep 1998; p. 47-48; 2. research coordination meeting on compilation and evaluation of photonuclear data for applications; Los Alamos, NM (United States); 23-26 Jun 1998; 4 refs
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Conference
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AbstractAbstract
[en] We develop an algorithm for the minimum Lp-norm solution to the two-dimensional phase unwrapping problem. Rather than its being a mathematically intractable problem, we show that the governing equations are equivalent to those that describe weighted least-squares phase unwrapping. The only exception is that the weights are data dependent. In addition, we show that the minimum Lp-norm solution is obtained by embedding the transform-based methods for unweighted and weighted least squares within a simple iterative structure. The data-dependent weights are generated within the algorithm and need not be supplied explicitly by the user. Interesting and useful solutions to many phase unwrapping problems can be obtained when p h 2. Specifically, the minimum L0-norm solution requires the solution phase gradients to equal the input data phase gradients in as many places as possible. This concept provides an interesting link to branch-cut unwrapping methods, where none existed previously. copyright 1996 Optical Society of America
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Journal Article
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Journal of the Optical Society of America. Part A, Optics and Image Science; ISSN 0740-3232; 
; CODEN JOAOD6; v. 13(10); p. 1999-2013
; CODEN JOAOD6; v. 13(10); p. 1999-2013
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[en] The problem of adaptive estimates according to correlated observations is discussed. Investigation into adaptive procedure of estimation using the least square fir (LSF) while applying the dependent observations is conducted. Theorem on the LSF estimate consistency is proved. 3 refs
Original Title
O sostoyatel'nosti adaptivnykh otsenok po korrelirvoannym nablyudeniyam
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Chang Jinjiang.
International Centre for Theoretical Physics, Trieste (Italy)
International Centre for Theoretical Physics, Trieste (Italy)
AbstractAbstract
[en] Using the least square method, the problem for computing periodic solution of autonomous ordinary differential equations has been reduced to a problem of minimization on a normal plane. The conjugate gradient method is used to yield successive initial value, and the Runge-Kutta method is used to solve the initial value problem in the ordinary differential equations. So a new method for this problem is formed. As examples, it is applied to the Brusselator model and Field-Noyes model of Belousov-Zhabotinskii reactions. The numerical results obtained show that this method is very efficient. (author). 7 refs, 2 figs, 3 tabs
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Jan 1993; 11 p
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