• Title/Summary/Keyword: Pure sciences

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ON THE RADIUS OF CONVERGENCE OF SOME NEWTON-TYPE METHODS IN BANACH SPACES

  • Argyros, Ioannis K.;Hilout, Said
    • The Pure and Applied Mathematics
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    • v.18 no.3
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    • pp.219-230
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    • 2011
  • We determine the radius of convergence for some Newton{type methods (NTM) for approximating a locally unique solution of an equation in a Banach space setting. A comparison is given between the radii of (NTM) and Newton's method (NM). Numerical examples further validating the theoretical results are also provided in this study.

DIRECT FREQUENCY REPRESENTATION OF PULSE PATTERNS FOR CONTROLLED VOLTAGE SOURCE INVERTERS

  • Oleschuk, Valentin;Bose, Bimal K.
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.165-170
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    • 1998
  • The paper describes developed method of feedforward digital modulation of line-to-line voltage of 3-phase inverter for drive application. It is based on representation of parameters of output voltage of inverter in function of operating frequency of drive system. Pure algebraic control laws and big computational simplicity characterize this scheme of modulation. It has been presented results of simulation of adjustable drive systems with the method of pulse-width modulation described.

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ON THE CONVERGENCE OF NEWTON'S METHOD AND LOCALLY HOLDERIAN INVERSES OF OPERATORS

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.16 no.1
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    • pp.13-18
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    • 2009
  • A semilocal convergence analysis is provided for Newton's method in a Banach space. The inverses of the operators involved are only locally $H{\ddot{o}}lderian$. We make use of a point-based approximation and center-$H{\ddot{o}}lderian$ hypotheses for the inverses of the operators involved. Such an approach can be used to approximate solutions of equations involving nonsmooth operators.

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ISOTOPIC-SPECTRAL DETERMINATION OF CARBON IN HIGH PURITY INORGANIC MATERIALS

  • Lee, V.N.;Nemets, V.M.
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.477-480
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    • 1995
  • Isotopic-spectral method [I] was applicated for determination of carbon in silicate materials (pure silica, guartz glasses, geological probs etc.). Isotopic heterogeneous balancing of carbon in gaseous phase and solid samples was carried out at the temperature of $1500-1900^{\circ}K$. Spectroscopic measuring of isotope concentration in a balanced gas was made using the electron-vibrational band heads of CO molecules excited in HF discharge. Limits of detection of carbon concentrations appear to be $n^*10^{-6}$.

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A PROOF OF THE MOST IMPORTANT IDENTITY INVOLVED IN THE BETA FUNCTION

  • Choi, June-Sang
    • The Pure and Applied Mathematics
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    • v.4 no.1
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    • pp.71-76
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    • 1997
  • A new proof of the well-known identity involved in the Beta function B(p, q) is given by using the theory of hypergeometric series and a brief history of Gamma function is also provided. The method here is shown to be able to apply to evaluate some definite integrals.

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Partitioning of Si in Fe-Zr-Si-B Nanocrystalline Alloys

  • Waniewska, A.Slawska;Greneche, J.M.;A.Inoue
    • Journal of Magnetics
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    • v.4 no.1
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    • pp.1-4
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    • 1999
  • The microstructure and magnetic properties of$ Fe_{87}Zr_7Si_4B_2$ nanocrystalline alloys were studied by magnetization measurements and M ssbauer spectrometry over a wide temperature range. Three well resolved spectral components have been found and attributed to bcc-Fe grains (with almost pure iron structure), residual amorphous matrix enriched with solute elements and interfaces formed at the grain-matrix boundaries. It has been shown that, contrary to the expectation, during crystallization the atomic segregation occurs leading to the formation of primary bcc-Fe grains and the partition of Si atoms into the residual amorphous matrix.

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QR DECOMPOSITION IN NONLINEAR EXPERIMENTAL DESIGN

  • Oh, Im-Geol
    • The Pure and Applied Mathematics
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    • v.2 no.2
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    • pp.133-140
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    • 1995
  • The D-optimal design criterion for precise parameter estimation in nonlinear regression analysis is called the determinant criterion because the determinant of a matrix is to be maximized. In this thesis, we derive the gradient and the Hessian of the determinant criterion, and apply a QR decomposition for their efficient computations. We also propose an approximate form of the Hessian matrix which can be calculated from the first derivative of a model function with respect to the design variables. These equations can be used in a Gauss-Newton type iteration procedure.

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ELEMENTARY DISKS IN TRUNCATED TRIANGULATIONS

  • Kang, Ensil
    • The Pure and Applied Mathematics
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    • v.22 no.1
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    • pp.91-99
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    • 2015
  • A normal surface is determined by how the surface under consideration meets each tetrahedron in a given triangulation. We call such a nice embedded disk, which is a component of the intersection of the surface with a tetrahedron, an elementary disk. We classify all elementary disk types in a truncated ideal triangulation.