• Title/Summary/Keyword: W-function

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Interaction Between the Viscous and Wavemaking Component Resistance (점성저항과 조파 저항 성분의 상호작용)

  • Kim, In-Chull
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.19 no.2
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    • pp.125-129
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    • 1983
  • It is customary to assume that the resistance of a jull at uniform speed may be regarded as the sum of viscous and wavemaking component resistance, or C sub(i)=C sub(v)+C sub(w), where C sub(v) is regarded as a function of Reynolds Number R and C sub(w) a function of Froude Number F. Formulae have been obtained for ∂C sub(w)/∂R, ∂C sub(v)/∂F which may be relevant in seeking theoretical grounds for possible interaction between viscous and wavemaking component resistances. The values of ∂C sub(w)/∂R are small. In general they are smaller than corresponding values of ∂C sub(v)/∂R. But although these values are small it does not follow that they are entirely negligible. The Froude assumption that the rate of change of C sub(w) with R is zero must bel regarded as incorrect.

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Efficiency enhancement of the organic light-emitting diodes by oxygen plasma treatment of the ITO substrate

  • Hong, J.W.;Oh, D.H.;Kim, C.H.;Kim, G.Y.;Kim, T.W.
    • Journal of Ceramic Processing Research
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    • v.13 no.spc2
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    • pp.193-197
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    • 2012
  • Oxygen plasma has been treated on the surface of indium-tin-oxide (ITO) to improve the efficiency of the organic light-emitting diodes (OLEDs) device. The plasma treatment was expected to inject the holes effectively due to the control of an ITO work-function and the reduction of surface roughness. To optimize the treatment condition, a surface resistance and morphology of the ITO surface were investigated. The effect on the electrical properties of the OLEDs was evaluated as a function of oxygen plasma powers (0, 200, 250, 300, and 450 W). The electrical properties of the devices were measured in a device structure of ITO/TPD/Alq3/BCP/LiF/Al. It was found the plasma treatment of the ITO surface affects on the efficiency of the device. The efficiency of the device was optimized at the plasma power of 250 W and decreased at higher power than 250 W. The maximum values of luminance, luminous power efficiency, and external quantum efficiency of the plasma treated devices increase by 1.4 times, 1.4 times, and 1.2 times, respectively, compared to those of the non-treated ones.

A STUDY ON INCOMPRESSIBLE FLOW COMPUTATIONS USING A HERMITE STREAM FUNCTION (Hermite 유동함수를 이용한 비압축성 유동계산에 대한 연구)

  • Kim, J.W.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.61-65
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    • 2006
  • This paper describes a recent development on the divergence free basis function based on a hermite stream function. The well-known cavity problem has been used to compare the accuracy and the convergence of the present method with those of a modified residual method known as one of the stabilized finite element methods. The comparison showed the present method performs better in the accuracy and convergence.

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IMPROVED STATIONARY $L_p$-APPROXIMATION ORDER OF INTERPOLATION BY CONDITIONALLY POSITIVE DEFINITE FUNCTIONS

  • Yoon, Jung-Ho
    • Journal of applied mathematics & informatics
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    • v.14 no.1_2
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    • pp.365-376
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    • 2004
  • The purpose of this study is to show that the accuracy of the interpolation method can be at least doubled when additional smoothness requirements and boundary conditions are met. In particular, as a basis function, we are interested in using a conditionally positive definite function $\Phi$ whose generalized Fourier transform is of the form $\Phi(\theta)\;=\;F(\theta)$\mid$\theta$\mid$^{-2m}$ with a bounded function F > 0.

A Study on the wiring Control Method of Hand & Auto Operation of an easy Elevator (간이 승강기 수.자동 배선제어방식에 관한 연구)

  • Wee, Sung-Dong;Gu, Hal-Bon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.596-602
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    • 2002
  • An easy elevator for learning originated is opened to compare the existed learning equipment, and it had a high studying efficient that the sequence control circuit can opens and closes with the wire. The structure of equipment to be controlled from the first floor to the fifth floors is demonstrated a constructive apparatus by a lamp atc to express the function of the open-close of the door according to the cage moving with a mechanical actuation of the forward-reverse breaker and the motor of load and a mechanical actuation of hand-operation control components of push-button S/W and L/S and relay etc. These components let connects each other in order to control of the elevator function with the auto program and the designed sequence control circuit. Consequent1y the process of these functions of 1~5steps could operates the cage with an auto program of the elevator and the sequence control circuit. The sequence control circuit is controlled by the step of forward and reverse to follow as that the sensor function of the L/S1~L/S5 let posit with the control switchs of S/W1~S/W5 of PLC testing panel and switchs of S/W1~S/W5 installed on the transparent acryl plate of the frame. In here, improved apparatus is a hand-auto operation combined learning equipment to study the principle and a technique of the originated sequence control circuit and the auto program of PLC.

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A Study on the Parameter Estimation for Testing Effort Function of Software (소프트웨어 테스트 노력 함수의 파라미터 산출에 관한 연구)

  • 최규식;김필중
    • Journal of Information Technology Applications and Management
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    • v.11 no.2
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    • pp.191-204
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    • 2004
  • Many software reliability growth model(SRGM) have been proposed for past several decades. Most of these propositions assumed the S/W debugging testing efforts be constant or even did not consider them. A few papers were presented as the software reliability evaluation considering the testing effort was important afterwards. The testing effort forms which have been presented by this kind of papers were exponential, Rayleigh, Weibull, or Logistic functions, and one of these 4 types was used as a testing effort function depending on the S/W developing circumstances. We consider the methology to evaluate the SRGN using least square estimator(LSE) and maximum likelihood estimator(MLE) for those 4 functions, and then examine parameters applying actual data adopted from real field test of developing S/W.

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Fractional Integrals and Generalized Olsen Inequalities

  • Gunawan, Hendra;Eridani, Eridani
    • Kyungpook Mathematical Journal
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    • v.49 no.1
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    • pp.31-39
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    • 2009
  • Let $T_{\rho}$ be the generalized fractional integral operator associated to a function ${\rho}:(0,{\infty}){\rightarrow}(0,{\infty})$, as defined in [16]. For a function W on $\mathbb{R}^n$, we shall be interested in the boundedness of the multiplication operator $f{\mapsto}W{\cdot}T_{\rho}f$ on generalized Morrey spaces. Under some assumptions on ${\rho}$, we obtain an inequality for $W{\cdot}T_{\rho}$, which can be viewed as an extension of Olsen's and Kurata-Nishigaki-Sugano's results.

FIRST PASSAGE PROBLEM FOR WIENER PATHS CROSSING DIFFERENTIABLE CURVES

  • Jang, Yu-Seon;Kim, Sung-Lai;Kim, Sung-Kyun
    • Journal of applied mathematics & informatics
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    • v.19 no.1_2
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    • pp.475-484
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    • 2005
  • Let W(t) be a Wiener path, let $\xi\;:\;[0,\;{\infty})\;\to\;\mathbb{R}$ be a continuous and increasing function satisfying $\xi$(0) > 0, let $$T_{/xi}=inf\{t{\geq}0\;:\;W(t){\geq}\xi(t)\}$$ be the first-passage time of W over $\xi$, and let F denote the distribution function of $T_{\xi}$. Then the first passage problem has a unique continuous solution as following $$F(t)=u(t)+{\sum_{n=1}^\infty}\int_0^t\;H_n(t,s)u(s)ds$$, where $$u(t)=2\Psi(\xi(t)/\sqrt{t})\;and\;H_1(t,s)=d\Phi\;(\{\xi(t)-\xi(s)\}/\sqrt{t-s})/ds\;for\;0\;{\leq}\;s.

Acridine Orange-induced Changes in Cell Wall of Salmonella pullorum (Acridine Orange에 의한 Salmonella pullorum의 세포벽 변화)

  • Kim, Jong-bae;Mah, Jum-sool
    • Korean Journal of Veterinary Research
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    • v.25 no.2
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    • pp.149-153
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    • 1985
  • Salmonella pullorum strain W was serially passaged on the brain heart infusion agar containing acrdine orange(AO) as a concentration of 100 mcg/ml. S. pullorum AO60 and S. pullorum AO150, which were subcultured 60 and 150 passages on AO media, were examined for permeability barrier function of the cell wall. AO60 and AO150 were appeared to be decreased in susceptibility against hydrophobic substances such as crystal violet, chloramphenicol and rifamycin, which might be resulted from the changes of permeability barrier function of the cell wall. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of bacterial protein, the protein profiles of AO6O and AO150 didn't differ significantly from W, but increased amount of the band of MW 140,000-145,000 was confirmed. And [G+C] contents of DNA in AO60 and A0150 were decreased than that of W.

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On Some Lacunary Generalized Difference Sequence Spaces of Invariant Means De ned by a Sequence of Modulus Function

  • Atici, Gulcan;Bektas, Cigdem Asma
    • Kyungpook Mathematical Journal
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    • v.51 no.4
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    • pp.385-393
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    • 2011
  • The aim of this paper is to introduce and study the sequence spaces [w, ${\theta}$, F, p, q]$_{\infty}({\Delta}_{\upsilon}^m)$, [w, ${\theta}$, F, p, q]$_1({\Delta}_{\upsilon}^m)$ and [w, ${\theta}$, F, p, q]$_0({\Delta}_{\upsilon}^m)$, which arise from the notions of generalized difference sequence space, lacunary convergence, invariant mean and a sequence of Moduli $F=(f_k)$. We establish some inclusion relations between these spaces under some conditions.