• Title/Summary/Keyword: Special parameters

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Numerical measures of Indicating Placement of Posets on Scale from Chains to Antichains

  • Bae, Kyoung-Yul
    • The Journal of Information Technology and Database
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    • v.3 no.1
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    • pp.97-108
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    • 1996
  • In this paper we obtain several function defined on finite partially ordered sets(posets) which may indicate constraints of comparability on sets of teams(tasks, etc.) for which evaluation is computationally simple, a relatively rare condition in graph-based algorithms. Using these functions a set of numerical coefficients and associated distributions obtained from a computer simulation of certain families of random graphs is determined. From this information estimates may be made as to the actual linearity of complicated posets. Applications of these ideas is to all areas where obtaining rankings from partial information in rational ways is relevant as in, e.g., team_, scaling_, and scheduling theory as well as in theoretical computer science. Theoretical consideration of special and desirable properties of various functions is provided permitting judgment concerning sensitivity of these functions to changes in parameters describing (finite) posets.

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Parametric Blind Restoration of Bi-level Images with Unknown Intensities

  • Kim, Daeun;Ahn, Sohyun;Kim, Jeongtae
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.5
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    • pp.319-322
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    • 2016
  • We propose a parametric blind deconvolution method for bi-level images with unknown intensity levels that estimates unknown parameters for point spread functions and images by minimizing a penalized nonlinear least squares objective function based on normalized correlation coefficients and two regularization functions. Unlike conventional methods, the proposed method does not require knowledge about true intensity values. Moreover, the objective function of the proposed method can be effectively minimized, since it has the special structure of nonlinear least squares. We demonstrate the effectiveness of the proposed method through simulations and experiments.

Electromagnetic Scattering of Inhomogeneous Dielectric Body using Tetrahedral Modeling Method (체적요소기법을 이용한 비균질 유전체의 산란특성)

  • Bae, Geon-Sik;Kim, Che-Young
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1747-1749
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    • 1996
  • A method for calculating the electromagnetic scattering from arid internal field distribution of arbitrally, shaped, inhomogeneous dielectric bodies is presented. Tetrahedral volume elements are used to model a scattering body in which the electrical parameters are defined constant in each tetrahedron. Special basis functions are defined within the tetrahedral volume elements to satisfy the boundary condition at interfaces between different dielectric media. In order to test the accuracy of the solution by using the present method, it is applied to obtain the scattered field by the dielectric sphere. The accuracy of the fields calculated by using the tetrahedral cell method is found to be comparable to that of others.

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Convexity preserving piecewise rational interpolation for planar curves

  • Sarfraz, Muhammad
    • Bulletin of the Korean Mathematical Society
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    • v.29 no.2
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    • pp.193-200
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    • 1992
  • This paper uses a piecewise ratonal cubic interpolant to solve the problem of shape preserving interpolation for plane curves; scalar curves are also considered as a special case. The results derived here are actually the extensions of the convexity preserving results of Delbourgo and Gregory [Delbourgo and Gregory'85] who developed a $C^{1}$ shape preserving interpolation scheme for scalar curves using the same piecewise rational function. They derived the ocnstraints, on the shape parameters occuring in the rational function under discussion, to make the interpolant preserve the convex shape of the data. This paper begins with some preliminaries about the rational cubic interpolant. The constraints consistent with convex data, are derived in Sections 3. These constraints are dependent on the tangent vectors. The description of the tangent vectors, which are consistent and dependent on the given data, is made in Section 4. the convexity preserving results are explained with examples in Section 5.

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A Sequential Monte Carlo inference for longitudinal data with luespotted mud hopper data (짱뚱어 자료로 살펴본 장기 시계열 자료의 순차적 몬테 칼로 추론)

  • Choi, Il-Su
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.6
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    • pp.1341-1345
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    • 2005
  • Sequential Monte Carlo techniques are a set of powerful and versatile simulation-based methods to perform optimal state estimation in nonlinear non-Gaussian state-space models. We can use Monte Carlo particle filters adaptively, i.e. so that they simultaneously estimate the parameters and the signal. However, Sequential Monte Carlo techniques require the use of special panicle filtering techniques which suffer from several drawbacks. We consider here an alternative approach combining particle filtering and Sequential Hybrid Monte Carlo. We give some examples of applications in fisheries(luespotted mud hopper data).

ON FINITE SUMMATION FORMULAE FOR THE H-FUNCTION OF TWO VARIABLES

  • Gupta, K.C.;Garg, O.P.
    • Kyungpook Mathematical Journal
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    • v.18 no.2
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    • pp.211-215
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    • 1978
  • In the present paper, we obtain two new and interesting finite summation formulae for the H-function of two variables in a very neat and elegant form. The novel feature of the paper is that the method used here in deriving these formulae is simple and direct and does not impose heavy restrictions on the parameters involved. On account of the most general nature of the H-function of two variables, a number of related finite summation formulae for a number of other useful functions can also be obtained as special cases of our results. As an illustration, we have obtained here from our main results, the corresponding finite summation formulae for $Kamp{\acute{e}}$ de $F{\acute{e}}riet$ function. Appell's function and Gauss' hypergeometric function which are also believed to be new.

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New Mathematical Models with Core Loss Factor for Control of AC Motors

  • Shinnaka, Shinji
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.630-635
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    • 1998
  • This paper establishes in a new unified manner new mathematical models with core(iron) loss factor for two kinds of AC motors, induction and synchronous motors which are supposed to generate torque precisely or/and efficiently under vector controls. Our new models consist of three basic equations consistent with the others such as differential equation describing electromagnetic dynamics, torque equation describing torque generating mechanism, energy transmission equation describing how injected energy is wasted, saved or transmitted where all vector signals are defined in general frame of arbitrary instant angular velocity. It is clearly shown in our models that equivalent core-loss resistance can express appropriately and separately both eddy-current and hysteresis losses rather than mere vague loss. Proposed model of induction motor is the most compact in sense of the number of employed interior states and parameters. This compact model can also represent eddy-current and hysteresis losses of rotor as well as stator. For synchronous motor, saliency is taken into consideration. As well known model for cylindrical motor can be obtained directly from salient one as its special case.

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Negative Binomial Varying Coefficient Partially Linear Models

  • Kim, Young-Ju
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.809-817
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    • 2012
  • We propose a semiparametric inference for a generalized varying coefficient partially linear model(VCPLM) for negative binomial data. The VCPLM is useful to model real data in that varying coefficients are a special type of interaction between explanatory variables and partially linear models fit both parametric and nonparametric terms. The negative binomial distribution often arise in modelling count data which usually are overdispersed. The varying coefficient function estimators and regression parameters in generalized VCPLM are obtained by formulating a penalized likelihood through smoothing splines for negative binomial data when the shape parameter is known. The performance of the proposed method is then evaluated by simulations.

Study on Slice Sensitivity Profile and Reconstruction Resolution on Helical CT System (Helical CT 시스템에 있어 Slice Sensitivity Profile과 Reconstruction Resolution에 관한 연구)

  • Yoon, Han-Sik
    • Journal of radiological science and technology
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    • v.20 no.1
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    • pp.15-20
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    • 1997
  • Unlike conventional CT scan, the helical CT scan uses continuous rotating CT equipment with a slip ring to move the patient's coach at a constant speed while continuously scanning. Slice sensitivity profiles in the Z-position(SSPz) using the conventional X-ray CT have a shape similiar to a rectangular wave, which slightly spreads out into plains below the mountain. However, in the helical CT, with an expansion of the base, the rectangular shape collapses and a mouatain-like shape can be seen. We need to investigate the fellowing factors in helical CT scanning;the ability to scan along the axis of the body, effective slice width, slice shape and the precision of coach velocity, Helical scanning with sprial X-ray track is different from the conventional scanning in terms of the principle of image reconstruction performed. We believe that the problems in helical scanning can be solved by understanding new the special parameters such as the bed moving speed and the interval of image reconstruction.

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Design evaluation of wind turbine pitch/yaw bearings by contact stress analysis (응력해석을 통한 풍력 발전기용 피치/요 베어링 설계 검증)

  • Ka, Jaewon;Kim, JaeDong;Nam, Yongyun;Rim, Chaewhan;Park, Youngjun;Bang, Jesung;Lee, Youngshin
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.43.2-43.2
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    • 2011
  • Wind turbine pitch/yaw bearings are relatively big and have different operating conditions like very heavy load to support compared with widely used industrial bearings. Once pitch/yaw bearings failed, according to their special surroundings, serious damages like higher repair costs and additional costs by stopped electricity generation are occur. Therefore, pitch/yaw bearings must be designed to have enough strength and fatigue life under actual operating conditions. In this study, with finite element analysis, it was investigated that stress distribution between rolling elements and raceway and comparatively analyzed using widely used guideline (NREL DG03). Design parameters of wind turbine pitch/yaw bearings are also analyzed, and it could be used as reference for the large bearing design field.

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