ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel  (32)
  • AMS(MOS): 65N30  (12)
  • kriging  (11)
  • AMS(MOS): 65D15  (9)
  • Springer  (32)
  • American Institute of Physics
  • Annual Reviews
  • Blackwell Publishing Ltd
  • Elsevier
  • Periodicals Archive Online (PAO)
  • Wiley
  • 2005-2009
  • 1990-1994
  • 1980-1984  (32)
  • 2008
  • 2007
  • 1983  (12)
  • 1982  (13)
  • 1980  (7)
  • Mathematik  (32)
Sammlung
  • Artikel  (32)
Datenquelle
Schlagwörter
Verlag/Herausgeber
  • Springer  (32)
  • American Institute of Physics
  • Annual Reviews
  • Blackwell Publishing Ltd
  • Elsevier
    • +
Erscheinungszeitraum
  • 2005-2009
  • 1990-1994
  • 1980-1984  (32)
Jahr
Thema
  • 1
    Digitale Medien
    Digitale Medien
    The ɛ-algorithm and multivariate Padé-approximants (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 39-46 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In the univariate case the ɛ-algorithm of Wynn is closely related to the Padé-table in the following sense: if we apply the ɛ-algorithm to the partial sums of the power series $$f(x) = \sum\limits_{i = 0}^\infty {c_i x^i } $$ then ε 2m l−m is the (l, m) Padé-approximant tof(x) wherel is the degree of the numerator andm is the degree of the denominator [1 pp. 66–68]. Several generalizations of the ɛ-algorithm exist but without any connection with a theory of Padé-approximants. Also several definitions of the Padé-approximant to a multivariate function exist, but up till now without any connection with the ɛ-algorithm. In this paper, we see that the multivariate Padé-approximants introduced in [3], satisfy the same property as the univariate Padé-approximants: if we apply the ɛ-algorithm to the partial sums of the power series $$f\left( {x_1 ,...,x_n } \right) = \sum\limits_{i_1 + ... + i_n = 0}^\infty {c_{i_1 ...i_n } x_1^{i_1 } ...x_n^{i_n } } $$ then ε 2m (l−m) is the (l, m) multivariate Padé-approximant tof(x 1, ...,x n ).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01459073
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    A stable method for the evaluation of a polynomial and of a rational function of one variable (1983)
    Springer
    Numerische Mathematik 41 (1983), S. 309-319 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; 65G05 ; CR: 5.11
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary It is shown that if one uses a carefully defined concept of stability (Stewart, G.W., Introduction to matrix computations, Academic Press, New York and London, 1973) then Horner's rule for the evaluation of a polynomial and some other evaluation methods are not always stable. A method is presented which is always stable. The operations count for this method is the same as that for Horner's rule. The method is generalized to apply to all rational functions of one variable.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01418328
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Maximum-norm stability and error estimates in Galerkin methods for parabolic equations in one space variable (1983)
    Springer
    Numerische Mathematik 41 (1983), S. 345-371 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Maximum-norm stability and error estimates of best approximation and nonsmooth data types are derived for the approximate solution of a parabolic equation in one space variable, using the continuous in time Galerkin method based on piecewise polynomial approximating functions on a quasi-uniform mesh.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01418330
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    A mixed finite element approximation of the Navier-Stokes equations (1980)
    Springer
    Numerische Mathematik 35 (1980), S. 381-404 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We study in this paper the convergence of a new mixed finite element approximation of the Navier-Stokes equations. This approximation uses low order Lagrange elements, leads to optimal order of convergence for the velocity and the pressure, and induces an efficient numerical algorithm for the solution of this problem.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399007
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Solving complex approximation problems by semiinfinite - finite optimization techniques: A study on convergence (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 411-420 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We transform a complex approximation problem into an equivalent semiinfinite optimization problem whose constraints are described in terms of a quantity ϕ∈[0,2π[=I. We study the effect of disturbing the problem by replacingI by a compact subsetM⊂I which includes as special case the discrete case whereM consists only of finitely many points. We introduce a measure ɛ for the deviation ofM fromI and show that in any complex approximation problem the minimal distance of the disturbed problem converges quadratically with ɛ→0 to the minimal distance of the undisturbed problem which is a generalization of a result by Streit and Nuttall. We also show that in a linear finite dimensional approximation problem the convergence of the coefficients of the disturbed problem is in general at most linear. There are some graphical representations of best complex approximations computed with the described method.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01407872
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Quotienten-Differenzen-Algorithmus: Beweis der Regeln von Rutishauser (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 93-98 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.15
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Der Quotienten-Differenzen-Algorithmus nach Rutishauser ist geeignet zur Bestimmung von Polen meromorpher Funktionen, gegeben durch eine Taylorreihe. Sind mehrere Pole betragsgleich, so kann eine Polynomfolge bestimmt werden, deren Grenzpolynom diese Pole als Nullstellen hat. Die Konvergenz wurde von Rutishauser jedoch nicht bewiesen. Ein Beweis wird in der vorliegenden Arbeit präsentiert.
    Notizen: Summary The Quotient-Difference Algorithm of Rutishauser can be used for the determination of poles of a meromorphic function given by its power series. If some of the poles have same modulus, a sequence of polynomials can be determined such that the limiting polynomial has exactly these poles as zeros. The convergence has not been proved by Rutishauser, however. A proof is presented in this paper.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01459078
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Unicity of best one-sidedL 1-approximations (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 229-243 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This paper deals with the problem of uniqueness in one-sidedL 1-approximation. The chief purpose is to characterize finite dimensional subspacesG of the space of continuous or differentiable functions which have a unique best one-sidedL 1-approximation. In addition, we study a related problem in moment theory. These considerations have an important application to the uniqueness of quadrature formulae of highest possible degree of precision.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01400541
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    The finite element method for parabolic equations (1982)
    Springer
    Numerische Mathematik 40 (1982), S. 339-371 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; 65M20 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this first of two papers, computable a posteriori estimates of the space discretization error in the finite element method of lines solution of parabolic equations are analyzed for time-independent space meshes. The effectiveness of the error estimator is related to conditions on the solution regularity, mesh family type, and asymptotic range for the mesh size. For clarity the results are limited to a model problem in which piecewise linear elements in one space dimension are used. The results extend straight-forwardly to systems of equations and higher order elements in one space dimension, while the higher dimensional case requires additional considerations. The theory presented here provides the basis for the analysis and adaptive construction of time-dependent space meshes, which is the subject of the second paper. Computational results show that the approach is practically very effective and suggest that it can be used for solving more general problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396451
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Error analysis for Laplace transform —Finite element solution of hyperbolic equations (1983)
    Springer
    Numerische Mathematik 41 (1983), S. 55-62 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The finite element method with Laplace transform of time variable is proposed for the solution of hyperbolic equations. Error estimates in Hardy spaces of functions with values in Sobolev spaces are derived. Due to the isometric isomorphism of Hardy spaces with weighted Hilbert spaces these estimates are valid also for original formulations of hyperbolic equations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396305
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    An analysis of thep-version of the finite element method for nearly incompressible materials (1983)
    Springer
    Numerische Mathematik 41 (1983), S. 39-53 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; 73K25 CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper we analyze the behavior of the so-calledp-version of the finite element method when applied to the equations of plane strain linear elasticity. We establish optimal rate error estimates that are uniformly valid, independent of the value of the Poisson ratio,v, in the interval ]0, 1/2[. This shows that thep-versiondoes not exhibit the degeneracy phenomenon which has led to the use of various, only partially justified techniques of reduced integration or mixed formulations for more standard finite element schemes and the case of a nearly incompressible material.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396304
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 11
    Digitale Medien
    Digitale Medien
    A Remez type algorithm for spline functions (1983)
    Springer
    Numerische Mathematik 41 (1983), S. 117-146 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A Remez type algorithm for computing best spline approximations of degreen withk fixed knots is developed. It is shown that the sequence constructed in the algorithm converges to a best approximation, ifk≦n+1, and at least to a nearly best approximation, ifk〉n+1. In contrast to the standard interpolation methods no restriction to the position of the knots is required. This fact may be important to treat approximation problems for splines with free knots.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396309
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    On conforming finite element methods for the inhomogeneous stationary Navier-Stokes equations (1983)
    Springer
    Numerische Mathematik 42 (1983), S. 173-194 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary We consider the stationary Navier-Stokes equations, written in terms of the primitive variables, in the case where both the partial differential equations and boundary conditions are inhomogeneous. Under certain conditions on the data, the existence and uniqueness of the solution of a weak formulation of the equations can be guaranteed. A conforming finite element method is presented and optimal estimates for the error of the approximate solution are proved. In addition, the convergence properties of iterative methods for the solution of the discrete nonlinear algebraic systems resulting from the finite element algorithm are given. Numerical examples, using an efficient choice of finite element spaces, are also provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395310
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    The QD-algorithm and multivariate Padé-approximants (1983)
    Springer
    Numerische Mathematik 42 (1983), S. 259-269 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The quotient-difference (QD) algorithm can be used to construct univariate Padé-approximants [1]. In this paper we see that it can also be used to construct the multivariate Padé-approximants introduced in [3], just by reformulating the quotient-difference algorithm as in Sect. 1. The multivariate Padé-approximants and the multivariate QD-scheme are treated in the Sects. 2 and 3 respectively. Thus for this type of multivariate Padé-approximants a link with the theory of multivariate continued fractions is established.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01389572
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    Strong uniqueness and second order convergence in nonlinear discrete approximation (1980)
    Springer
    Numerische Mathematik 34 (1980), S. 439-455 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary Strong uniqueness has proved to be an important condition in demonstrating the second order convergence of the generalised Gauss-Newton method for discrete nonlinear approximation problems [4]. Here we compare strong uniqueness with the multiplier condition which has also been used for this purpose. We describe strong uniqueness in terms of the local geometry of the unit ball and properties of the problem functions at the minimum point. When the norm is polyhedral we are able to give necessary and sufficient conditions for the second order convergence of the generalised Gauss-Newton algorithm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01403680
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    Existence and approximation results for nonlinear mixed problems: Application to incompressible finite elasticity (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 365-382 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary This paper considers the problems of minimizing Gateaux-differentiable functionals over subsets of real Banach spaces defined by a non-linear equality constraint. The existence of a Lagrange multiplier is proved, together with approximation results on the constrained subset, provided a nonlinear compatibility condition, generalizing the classical inf-sup condition, is satisfied. These ideas are applied to equilibrium problems in incompressible finite elasticity and lead to convergence results for these problems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396438
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    The numerical solutions of interface problems by infinite element method (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 39-50 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper we derive error estimates for infinite element method used in the approximation of solutions of interface problems. Furthermore, approximations of stress intensity factors are given. The infinite element method may be considered as a certain scheme of mesh refinement, but it has the advantages that the refinement is easy to be constructed that the stiffness matrix can be calculated efficiently, and that an approximate solution which has a singularity at the singular point can be also obtained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399310
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Optimal cycles in doubly weighted graphs and approximation of bivariate functions by univariate ones (1982)
    Springer
    Numerische Mathematik 39 (1982), S. 65-84 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65D15 ; CR: 5.13
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary The problem of finding optimal cycles in a doubly weighted directed graph (Problem A) is closely related to the problem of approximating bivariate functions by the sum of two univariate functions with respect to the supremum norm (Problem B). The close relationship between Problem A and Problem B is detected by the characterization (7.4) of the distance dist (f, t) of Problem B. In Part 1 we construct an algorithm for Problem A where the essential role is played by the minimal lengthsy j(k) defined by (2.3). If weight functiont≡1 then the minimum of Problem A is computed by equality (2.4). Ift≡1 then the minimum is obtained by a binary search procedure, Algorithm 3. In Part 2 we construct our algorithms for solving Problem B by following exactly the ideas of Part 1. By Algorithm 4 we compute the minimal pseudolengthsh k(y, M) defined by (7.5). If weight functiont≡1 then the infimum dist(f,t) of Problem B is obtained by equality (7.12) which is closely related to (2.4). Ift≢1 we compute the infimum dist(f,t) by the binary search procedure Algorithm 5. Additionally, Algorithm 4 leads to a constructive proof of the existence of continuous optimal solutions of Problem B (see Theorem 7.1e) which is already known in caset≡1 but unknown in caset≢1. Interesting applications to the steady-state behaviour of industrial processes with interference (Sect. 3) and the solution of integral equations (Problem C) are included.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01399312
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    Analysis of finite element methods for second order boundary value problems using mesh dependent norms (1980)
    Springer
    Numerische Mathematik 34 (1980), S. 41-62 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Abstract This paper presents a new approach to the analysis of finite element methods based onC 0-finite elements for the approximate solution of 2nd order boundary value problems in which error estimates are derived directly in terms of two mesh dependent norms that are closely ralated to theL 2 norm and to the 2nd order Sobolev norm, respectively, and in which there is no assumption of quasi-uniformity on the mesh family. This is in contrast to the usual analysis in which error estimates are first derived in the 1st order Sobolev norm and subsequently are derived in theL 2 norm and in the 2nd order Sobolev norm — the 2nd order Sobolev norm estimates being obtained under the assumption that the functions in the underlying approximating subspaces lie in the 2nd order Sobolev space and that the mesh family is quasi-uniform.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01463997
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    Convergence of the nonconforming Wilson element for arbitrary quadrilateral meshes (1980)
    Springer
    Numerische Mathematik 36 (1980), S. 33-52 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary A modified variational formulation, recently introduced by Taylor, Beresford and Wilson for solving second order problems, using the nonconforming Wilson element is here analysed. It is shown that the Patch Test is satisfied and that stresses and displacements are respectively first and second order accurate for arbitrary quadrilateral meshes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395987
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    A finite element lumped mass scheme for solving eigenvalue problems of circular arches (1980)
    Springer
    Numerische Mathematik 36 (1980), S. 267-290 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In this paper, we present a finite element lumped mass scheme for eigenvalue problems of circular arch structures, and give error estimates for the approximation. They assert that approximate eigenvalues and eigenfuctions converge to the exact ones. Some numerical examples are also given to illustrate our results.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01396655
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 21
    Digitale Medien
    Digitale Medien
    Finite dimensional approximation of nonlinear problems (1982)
    Springer
    Numerische Mathematik 38 (1982), S. 1-30 
    Details
    ISSN: 0945-3245
    Schlagwort(e): AMS(MOS): 65N30 ; CR: 5.17
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Summary In the first two papers of this series [4, 5], we have studied a general method of approximation of nonsingular solutions and simple limit points of nonlinear equations in a Banach space. We derive here general approximation results of the branches of solutions in the neighborhood of a simple bifurcation point. The abstract theory is applied to the Galerkin approximation of nonlinear variational problems and to a mixed finite element approximation of the von Kármán equations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01395805
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 22
    Digitale Medien
    Digitale Medien
    Statistical and geostatistical methods applied to the exploration work of the Nanisivik Zn-Pb mine, Baffin Island, Canada (1980)
    Springer
    Mathematical geology 12 (1980), S. 321-337 
    Details
    ISSN: 1573-8868
    Schlagwort(e): geostatistics ; kriging ; variogram analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract The Nanisivik Pb-Zn deposit at Strathcona Sound, northern Baffin Island, Canada, is an orebody that is an S-shaped lens 3000 m long, 75 m wide, and 2–20 m thick. It is an epigenetic karst channel filling. Total reserves are 6.9 million short tons of 14.12% Zn, 1.4% Pb, and 1.77 oz of Ag per ton. The mine was brought into production in 1976 at a rate of 2000 short tons per day. In the preproduction phase variogram studies based only on surface holes indicated a random distribution. For the evaluation of grades and for the determination of the confidence limits, classic statistical procedures were applied. Since the drilling density was different in different ore zones, a model was developed to test the effect of different drill hole spacings on the uncertainties in the present value in a discounted cash flow model. After the initial development and mining stage, structures could be recognized in semivariograms. Studies for a best drilling grid showed that the pattern of 25 ×20 m used in the mine could be extended to 35 ×35 m, taking into account that eight stopes are mined simultaneously. For ore reserve calculations weighing factors were calculated by kriging for six universally applicable geometric situations. Only the drill holes within a block and immediately surrounding it were taken into account. A test in a well-known zone yielded satisfactory results. A test to predict highs and lows of the grade accurately enough to optimally place the pillars failed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01029419
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 23
    Digitale Medien
    Digitale Medien
    Lognormal kriging—the general case (1982)
    Springer
    Mathematical geology 14 (1982), S. 475-499 
    Details
    ISSN: 1573-8868
    Schlagwort(e): kriging ; lognormal estimation ; conservation of lognormality
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract A theoretical study of the general case of the estimation of regionalized variables with a lognormal distribution is presented. The results of this study are compared to those obtained assuming conservation of lognormality. The numerical significance of the different solutions is illustrated by several simple examples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01077535
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 24
    Digitale Medien
    Digitale Medien
    Variogram models for regional groundwater geochemical data (1982)
    Springer
    Mathematical geology 14 (1982), S. 629-644 
    Details
    ISSN: 1573-8868
    Schlagwort(e): variogram ; kriging ; interpolation ; contouring ; inverse distance weighting ; geochemical gradient
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Four variogram models for regional groundwater geochemical data are presented. These models were developed from an empirical study of the sample variograms for more than 10 elements in groundwaters from two geologic regions in the Plainview quandrangle, Texas. A procedure is given for the estimation of the variogram in the isotropic and anisotropic case. The variograms were found useful for quantifying the differences in spatial variability for elements within a geologic unit and for elements in different geologic units. Additionally, the variogram analysis enables assessment of the assumption of statistical independence of regional samples which is commonly used in many statistical procedures. The estimated variograms are used in computation of kriged estimates for the Plainview quadrangle data. The results indicate that an inverse distance weighting model was superior for prediction than simple kriging with the particular variograms used.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01033884
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 25
    Digitale Medien
    Digitale Medien
    The combination of sampling and kriging in the regional estimation of coal resources (1982)
    Springer
    Mathematical geology 14 (1982), S. 87-106 
    Details
    ISSN: 1573-8868
    Schlagwort(e): coal ; geostatistics ; kriging ; regional estimation ; systematic sampling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Two-dimensional systematic sampling of small plots followed by the kriging of those plots may be employed to obtain regional estimates of coal resources and measures of the accuracy of the estimates. The use of sampling makes large savings in computation possible. Two case studies involving the estimation of coal tonnage are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01083946
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 26
    Digitale Medien
    Digitale Medien
    Geostatistics as a tool to define various categories of resources (1983)
    Springer
    Mathematical geology 15 (1983), S. 131-143 
    Details
    ISSN: 1573-8868
    Schlagwort(e): Geostatistics ; resource classification ; mineral resources ; kriging ; resource definitions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Definition of “measured” and “indicated” resources tend to be vague. Yet, the calculation of such categories of resources in a mineral deposit calls for specific technical criteria, the selection of which depends upon the method of evaluation. This paper discusses how a geostatistical methodology provides the technical criteria required to classify reasonably assured resources by levels of assurance of their existence. A preliminary discussion concludes that the reasonably assured resources of a mineral deposit should be classified locally as in the traditional approach. However, the size of local volumes should not correspond to the elementary grid unit of drill holes but if possible to the minimum unit of selection that can be supported by the chosen mining method. The “level of confidence” of the reasonably assured resources can be quantitatively represented and determined by the estimation variance, one of the most important tools of geostatistics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01030079
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 27
    Digitale Medien
    Digitale Medien
    Kriging of water levels in the Souss aquifer, Morocco (1983)
    Springer
    Mathematical geology 15 (1983), S. 537-551 
    Details
    ISSN: 1573-8868
    Schlagwort(e): kriging ; drift ; least squares ; residuals ; water table
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Universal kriging is applied to water table data from the Souss aquifer in central Morocco. The procedure accounts for the spatial variability of the phenomenon to be mapped. With the use of measured elevations of the water table, an experimental variogram is constructed that characterizes the spatial variability of the measured water levels. Spherical and Gaussian variogram models are alternatively used to fit the experimental variogram. The models are used to develop contour maps of water table elevations and corresponding estimation variances. The estimation variances express the reliability of the kriged water table elevation maps. Universal kriging also provides a contour map of the expected elevation of the water table (drift). The differences between the expected and measured water table elevations are called residuals from the drift. Residuals from the drift are compared with residuals obtained by more traditional least-squares analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01031176
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 28
    Digitale Medien
    Digitale Medien
    Cross validation of kriging in a unique neighborhood (1983)
    Springer
    Mathematical geology 15 (1983), S. 687-699 
    Details
    ISSN: 1573-8868
    Schlagwort(e): cross validation ; kriging ; moving neighborhood ; unique neighborhood
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Cross validation is an appropriate tool for testing interpolation methods: it consists of leaving out one data point at a time, and determining how well this point can be estimated from the other data. Cross validation is often used for testing “moving neighborhood” kriging models; in this case, each unknown value is predicted from a small number of surrounding data. In “unique neighborhood” kriging algorithms, each estimation uses all the available data; as a result, cross validation would spend much computer time. For instance, with ndata points it would cost at least the resolution of nsystems of n × nlinear equations (each with a different matrix).Here, we present a much faster method for cross validation in a unique neighborhood. Instead of solving nsystems n × n,it only requires the inversion of one n × nmatrix. We also generalized this method to leaving out several points instead of one.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01033232
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    Robust estimation of the variogram: I (1980)
    Springer
    Mathematical geology 12 (1980), S. 115-125 
    Details
    ISSN: 1573-8868
    Schlagwort(e): Geostatistics ; kriging ; robust estimation ; variogram
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract It is a matter of common experience that ore values often do not follow the normal (or lognormal) distributions assumed for them, but, instead, follow some other heavier-tailed distribution. In this paper we discuss the robust estimation of the variogram when the distribution is normal-like in the central region but heavier than normal in the tails. It is shown that the use of a fourth-root transformation with or without the use of M-estimation yields stable robust estimates of the variogram.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01035243
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    Geostatistical case studies of the advantages of lognormal-de Wijsian kriging with mean for a base metal mine and a gold mine (1982)
    Springer
    Mathematical geology 14 (1982), S. 547-555 
    Details
    ISSN: 1573-8868
    Schlagwort(e): geostatistics ; kriging
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Parallel variogram analyses, block kriging, and follow-up studies were effected for the lead content of part of the Prieska copper-zinc ore body and for the gold content of the highly variable Breef in a section of the Loraine gold mine, based first on untransformed values and second on logarithmically transformed values using the lognormal-de Wijsian model. For both models the effect was also analyzed of using the population mean or ignoring it. Practical follow-up comparisons confirm theoretical considerations and show that on these mines conditional biases can be eliminated conveniently by kriging with mean; also that the lognormal-de Wijsian model with mean gives the best results.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01033878
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    Two methods with different objectives: Splines and kriging (1983)
    Springer
    Mathematical geology 15 (1983), S. 245-257 
    Details
    ISSN: 1573-8868
    Schlagwort(e): kriging ; splines ; measurement errors ; generalized covariance ; structural identification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract When drawing a contour map from a set of irregularly spaced data points, two methods are often used: The first corresponds to a rather aesthetic criterion and consists of obtaining contour lines which will be as “smooth”as possible and will honor the data points. This generally is the objective of the draftsman, and it can be automatically performed by the method of spline interpolation. The other method, used in kriging, is to compute the Best Linear Unbiased Estimator (B.L.U.E.),that is, to obtain a map as accurate as possible. Is it possible, in practice, to predict whether the aesthetic map will also be accurate? In this paper, we first examine the theoretical point of view: Spline interpolation is equivalent to kriging with a given (generalized)covariance. We then take an example to show how this question can be answered in practice: by testing how well the spline covariance is suited to the data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01036069
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    Integration of mineral resource data for Kasmere Lake area, Northwest Manitoba, with emphasis on uranium (1983)
    Springer
    Mathematical geology 15 (1983), S. 25-45 
    Details
    ISSN: 1573-8868
    Schlagwort(e): Discriminant analysis ; autocorrelation ; kriging ; multiple regression ; uranium ; mineral resources
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Mathematik
    Notizen: Abstract Geological and geophysical data digitized by Fabbri (1981)are augmented by eleven lakesediment geochemical variables in a quantitative study of the Kasmere Lake—Whiskey Jack Lake area, NW Manitoba. Each of 33 geological map units (Archean and Aphebian igneous and metamorphic rocks)have a fairly distinct multivariate geochemical and geophysical signal, as shown by discriminant analysis which is able to “recover” the geological map from the geophysical and geochemical data. Autocorrelation analysis of the geochemical variables, after removing a quadratic trend, indicate that copper, nickel, uranium, and cobait have a zone of influence from 15 to 30 km or more, with a marked anisotropy parallel to geological, geophysical, and structural trends which run NE-SW, parallel to the Wollaston fold belt. The observed uranium autocorrelation coefficients are modeled as a two-dimensional exponential function with elliptical contours. A trend-signal-noise model is applied to the lake-sediment uranium using kriging on residuals from the quadratic trend. A map comparing the resulting lake-sediment uranium signal with radiometric uranium/thorium patterns indicates considerable overlap and a generally good prediction of known uranium occurrences. In areas with a strong lake-sediment uranium signal, Aphebian metasediments have a somewhat different multivariate geochemical character from Archean and Hudsonian igneous and metamorphic rocks, suggesting a method of removing areas from the signal underlain by granites that may be economically uninteresting. Logistic and stepwise regression experiments based on a control area which includes most of the presently reported occurrences are used to predict areas favorable for uranium exploration.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01030074
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...