• Title/Summary/Keyword: exponential decay

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EXPONENTIAL DECAY OF $C^1$ LAGRANGE POLYNOMIAL SPLINES WITH RESPECT TO THE LOCAL CHEBYSHEV-GAUSS POINTS

  • Shin, Byeong-Chun;Song, Ho-Wan
    • Communications of the Korean Mathematical Society
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    • v.16 no.1
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    • pp.153-161
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    • 2001
  • In the course of working on the preconditioning $C^1$ polynomial spline collocation method, one has to deal with the exponential decay of $C^1$ Lagrange polynomial splines. In this paper we show the exponential decay of $C^1$ Lagrange polynomial splines using the Chebyshev-Gauss points as the local data points.

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Empirical Fitting Curve for Luminous Transmittance in Tinted Lenses Using Superposition of Exponential Decay Curves (지수감소곡선의 중첩을 이용한 착색렌즈 시감투과율의 실험적 맞춤곡선)

  • Choi, Eun Jung;Lee, Sin Ui;Lee, Eun Jin;Yoon, Moon Joo;Jeong, Ji-Hyeon;Kim, Chang-Jin;Yang, Gye Tak;Jeong, Ju-Hyun;Kim, Hyun Jung
    • Journal of Korean Ophthalmic Optics Society
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    • v.16 no.3
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    • pp.283-291
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    • 2011
  • Purpose: To find an empirical fitting curve to represent the relationship between the luminous transmittance and tinted time in tinted lenses using exponential decay curves. Methods: Total ninety tinted lenses were prepared with CR-39 lenses and six different colored dyes. Single, double and triple exponential decay curves were used as trial curves in order to find the empirical fitting curve. Result: The results showed that the best empirical fitting curve was triple exponential decay curves. Conclusions: We propose triple exponential decay curves as proper empirical fitting curves to represent the tinted-time dependence of the luminous transmittance in tinted lenses.

Mechanical degradation kinetics of poly(ethylene oxide) in a turbulent flow

  • Sung, Jun-Hee;Lim, Sung-Taek;Kim, Chul-Am;Heejeong Chung;Park, Hyoung-Jin
    • Korea-Australia Rheology Journal
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    • v.16 no.2
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    • pp.57-62
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    • 2004
  • Turbulent drag reduction (DR) efficiency of water soluble poly(ethylene oxide) (PEO) with two different molecular weights was studied as a function of polymer concentration and temperature in a turbulent flow produced via a rotating disk system. Its mechanical degradation behavior as a function of time in a turbulent flow was also analyzed using both a simple exponential decay function and a fractional exponential decay equation. The fractional exponential decay equation was found to fit the experimental data better than the simple exponential decay function. Its thermal degradation further exhibited that the susceptibility of PEO to degradation increases dramatically with increasing temperature.

LOCAL EXISTENCE AND EXPONENTIAL DECAY OF SOLUTIONS FOR A NONLINEAR PSEUDOPARABOLIC EQUATION WITH VISCOELASTIC TERM

  • Nhan, Nguyen Huu;Nhan, Truong Thi;Ngoc, Le Thi Phuong;Long, Nguyen Thanh
    • Nonlinear Functional Analysis and Applications
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    • v.26 no.1
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    • pp.35-64
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    • 2021
  • In this paper, we investigate an initial boundary value problem for a nonlinear pseudoparabolic equation. At first, by applying the Faedo-Galerkin, we prove local existence and uniqueness results. Next, by constructing Lyapunov functional, we establish a sufficient condition to obtain the global existence and exponential decay of weak solutions.

A Study of a Decay Parameter for the Dark Adaptation Function on the retina (망막에서 암순응 함수의 Decay parameter 연구)

  • Kim, Yong Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.145-150
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    • 2000
  • The adaptation for a right source on the retina consists of the light-dark adaptation's two curves for a time by the rod-cone receptor. We obtained the adaptation for a time to measure the threshold intensities, it was two decay curves by the center of a rod-cone break. It could be represented the dark adaptation by a exponential decay function consisting of $T_{min}$, $a_r$, $a_c$, $T_{0(r)}$, $T_{0(c)}$, $t_b$, $t_c$'s parameters. The curves of a $t_b$ below and a $t_b$ above showed the adaptation sensitivity of the cone and the rod. The exponential decay function was well applied to the dark adaptation in difference retinal positions, in contrally fixated fields, in luminous, as age etc. It could be used the decay parameter as the index because of representing the properties of the dark adaptation's function.

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Improvement of the Exponential Experiment System for the Automatical and Accurate Measurement of the Exponential Decay constant (지수감쇠계수의 자동 및 정밀 측정을 위한 지수실험장치 개선)

  • 신희성;장지운;이윤희;황용화;김호동
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.292-303
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    • 2004
  • The previous exponential experiment system has been improved for the automatical and accurate axial movement of the neutron source and detector with attaching the automatical control system which consists of a Programmable Logical Controller(PLC) and a stepping motor set. The automatic control program which controls MCA and PLC consistently has been also developed on the basis of GENIE 2000 Library. The exponential experiments have been carried out for Kori 1 unit spent fuel assemblies, Cl4, Jl4 and G23, and Kori 2 unit spent fuel assembly, J44, using the improved systematical measurement system. As the results, the average exponential decay constants for 4 assemblies are determined to be 0.1302, 0.1267, 0.1247, and 0.1210, respectively, with the application of Poisson regression.

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ENERGY DECAY RATE FOR THE KELVIN-VOIGT TYPE WAVE EQUATION WITH BALAKRISHNAN-TAYLOR DAMPING AND ACOUSTIC BOUNDARY

  • Kang, Yong Han
    • East Asian mathematical journal
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    • v.32 no.3
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    • pp.355-364
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    • 2016
  • In this paper, we study exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with Balakrishnan-Taylor damping and acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Kang [3]. Energy decay rate are obtained by the exponential stability of solutions by using multiplier technique.

ENERGY DECAY RATES FOR THE KELVIN-VOIGT TYPE WAVE EQUATION WITH ACOUSTIC BOUNDARY

  • Seo, Young-Il;Kang, Yong-Han
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.2
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    • pp.85-91
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    • 2012
  • In this paper, we study uniform exponential stabilization of the vibrations of the Kelvin-Voigt type wave equation with acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the internal material damping in the model as like Gannesh C. Gorain [1]. Energy decay rates are obtained by the exponential stability of solutions by using multiplier technique.

ENERGY DECAY RATE FOR THE KIRCHHOFF TYPE WAVE EQUATION WITH ACOUSTIC BOUNDARY

  • Kang, Yong-Han
    • East Asian mathematical journal
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    • v.28 no.3
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    • pp.339-345
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    • 2012
  • In this paper, we study uniform exponential stabilization of the vibrations of the Kirchho type wave equation with acoustic boundary in a bounded domain in $R^n$. To stabilize the system, we incorporate separately, the passive viscous damping in the model as like Gannesh C. Gorain [1]. Energy decay rate is obtained by the exponential stability of solutions by using multiplier technique.

ENERGY DECAY RATES FOR THE KIRCHHOFF TYPE WAVE EQUATION WITH BALAKRISHNAN-TAYLOR DAMPING AND ACOUSTIC BOUNDARY

  • Kang, Yong Han
    • East Asian mathematical journal
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    • v.30 no.3
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    • pp.249-258
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    • 2014
  • In this paper, we study uniform exponential stabilization of the vibrations of the Kirchhoff type wave equation with Balakrishnan-Taylor damping and acoustic boundary in a bounded domain in $R^n$. To stabilize the systems, we incorporate separately, the passive viscous damping in the model as like Kang[14]. Energy decay rates are obtained by the uniform exponential stability of solutions by using multiplier technique.