• Title/Summary/Keyword: Logarithm function

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Retinex-based Logarithm Transformation Method for Color Image Enhancement (컬러 이미지 화질 개선을 위한 Retinex 기반의 로그변환 기법)

  • Kim, Donghyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.9-16
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    • 2018
  • Images with lower illumination from the light source or with dark regions due to shadows, etc., can improve subjective image quality by using retinex-based image enhancement schemes. The retinex theory is a method that recognizes the relative lightness of a scene, rather than recognizing the brightness of the scene. The way the human visual system recognizes a scene in a specific position can be in one of several methods: single-scale retinex, multi-scale retinex, and multi-scale retinex with color restoration (MSRCR). The proposed method is based on the MSRCR method, which includes a color restoration step, which consists of three phases. In the first phase, the existing MSRCR method is applied. In the second phase, the dynamic range of the MSRCR output is adjusted according to its histogram. In the last phase, the proposed method transforms the retinex output value into the display dynamic range using a logarithm transformation function considering human visual system characteristics. Experimental results show that the proposed algorithm effectively increases the subjective image quality, not only in dark images but also in images including both bright and dark areas. Especially in a low lightness image, the proposed algorithm showed higher performance improvement than the conventional approaches.

ON THE RATES OF THE ALMOST SURE CONVERGENCE FOR SELF-NORMALIZED LAW OF THE ITERATED LOGARITHM

  • Pang, Tian-Xiao
    • Bulletin of the Korean Mathematical Society
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    • v.48 no.6
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    • pp.1137-1146
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    • 2011
  • Let {$X_i$, $i{\geq}1$} be a sequence of i.i.d. nondegenerate random variables which is in the domain of attraction of the normal law with mean zero and possibly infinite variance. Denote $S_n={\sum}_{i=1}^n\;X_i$, $M_n=max_{1{\leq}i{\leq}n}\;{\mid}S_i{\mid}$ and $V_n^2={\sum}_{i=1}^n\;X_i^2$. Then for d > -1, we showed that under some regularity conditions, $$\lim_{{\varepsilon}{\searrow}0}{\varepsilon}^2^{d+1}\sum_{n=1}^{\infty}\frac{(loglogn)^d}{nlogn}I\{M_n/V_n{\geq}\sqrt{2loglogn}({\varepsilon}+{\alpha}_n)\}=\frac{2}{\sqrt{\pi}(1+d)}{\Gamma}(d+3/2)\sum_{k=0}^{\infty}\frac{(-1)^k}{(2k+1)^{2d+2}}\;a.s.$$ holds in this paper, where If g denotes the indicator function.

Studies on the Reaction Mechanism of Azo Dyes with Cetyltrimethylammonium Bromide

  • Kim, Bak-Kwang;Sim, Kyl-Soon;Lee, Wang-Kyu
    • Journal of Pharmaceutical Investigation
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    • v.12 no.4
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    • pp.101-111
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    • 1982
  • The effect of salt addition to MO-CTB mixed micelle was studied. The logarithm of cmcs obtained from above experiment is a linear function of the logarithm of the sum of the cmc and the concentration of added salt. In order to investigate the relation of the color change and the structure, the measurement of conductance to the mixed micelle has been carried out. To see the color change and conductance data obtained in the present study, structure A is more probable one to the micelles having the ${\lambda}_{max}$ 376nm.

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CHARACTERIZATION OF POOL-RIFFLE SEQUENCES IN SOLUTE TRANSPORT MODELING OF STREAMS

  • Seo, Il-Won;Yu, Dae-young
    • Water Engineering Research
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    • v.1 no.3
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    • pp.171-185
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    • 2000
  • A mathematical model to adequately predict complex mixing characteristics of sorptive polluants in natural streams with pools-and-riffes has been developed. In this model, sorption of pollutants onto the bed sediment as well as mass storage and exchange in the storage zones were incorporated into one-dimensional mass balance equatins. The geometric and hydraulic characteristics of the pool-riffle sequences were properly conceptualized. Simulations with parameters of pool-and-riffle streams better fit the measured data in overall shape and peak concentration than simulations with parameters for uniform channels. The analyses on the characteristics of the storage zone model parameters reveal that a linear relationship between the logrithm of the storage zone volume ratio and a function of the friction factor exists. A linear relatiohship might also be tenatively assumed between the logarithm of the dimensionless mass exchange coefficient and the logarithm of the aspect ratio of the storage zone if some of the high values of the dimensionless mass exchange coefficient collected on the successive bed forms are excluded.

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SYMMETRIC IDENTITIES FOR DEGENERATE q-POLY-BERNOULLI NUMBERS AND POLYNOMIALS

  • JUNG, N.S.;RYOO, C.S.
    • Journal of applied mathematics & informatics
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    • v.36 no.1_2
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    • pp.29-38
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    • 2018
  • In this paper, we introduce a degenerate q-poly-Bernoulli numbers and polynomials include q-logarithm function. We derive some relations with this polynomials and the Stirling numbers of second kind and investigate some symmetric identities using special functions that are involving this polynomials.

IDENTITIES INVOLVING THE DEGENERATE GENERALIZED (p, q)-POLY-BERNOULLI NUMBERS AND POLYNOMIALS

  • JUNG, N.S.
    • Journal of applied mathematics & informatics
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    • v.38 no.5_6
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    • pp.601-609
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    • 2020
  • In this paper, we introduce degenerate generalized poly-Bernoulli numbers and polynomials with (p, q)-logarithm function. We find some identities that are concerned with the Stirling numbers of second kind and derive symmetric identities by using generalized falling factorial sum.

Superior and Inferior Limits on the Increments of Gaussian Processes

  • Park, Yong-Kab;Hwang, Kyo-Shin;Park, Soon-Kyu
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.57-74
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    • 1997
  • Csorgo-Revesz type theorems for Wiener process are developed to those for Gaussian process. In particular, some results of superior and inferior limits for the increments of a Gaussian process are differently obtained under mild conditions, via estimating probability inequalities on the suprema of a Gaussian process.

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A LAW OF ITERATED LOGARITHM FOR OCCUPATION TIME BROWNIAN IN ι$_2$

  • Cho, Nhan-Sook
    • Communications of the Korean Mathematical Society
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    • v.14 no.3
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    • pp.569-579
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    • 1999
  • We consider a random measure defined by the occupation time of Brownian motion in $l_2$. If it is normalized ${\lambda}^2$log then we show that its cluster set as ${\lambda}{longrightarrow}\infty$ can be represented by Ι-function on $\sigma$-finite measure in $l_2$.

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General Laws of the Iterated Logarithm for Levy Processes

  • Wee, In-Suk;Kim, Yun-Kyong
    • Journal of the Korean Statistical Society
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    • v.17 no.1
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    • pp.30-45
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    • 1988
  • Let ${X(t) : 0 \leq t < \infty}$ be a real-valued process with stationary independent increments. In this paper, we obtain necesary and sufficint condition for there to exist a positive, nondecreasing function $\beta(t)$ so that $0 < lim sup $\mid$X(t)$\mid$/\beta(t) < \infty$ a.s. both as t tends to zero and infinity. When no such $\beta(t)$ exists we give a simple integral test for whether $lim sup $\mid$X(t)$\mid$/\beta(t)$ is zero or infinity for a given $\beta(t)$.

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Effects of Water on the Electrical Conductivity of Magnesium Metaphosphate Glasses (MgO.$P_2O_5$ 유리의 전기전도도에 미치는 수분의 영향)

  • 강은태;박용완
    • Journal of the Korean Ceramic Society
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    • v.23 no.4
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    • pp.85-89
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    • 1986
  • Electrical conductivity have been measured as function of temperature in MgO.$P_2O_5$ glasses containing small amounts of water. Conduction was due to the contribution of $H^+$ and the mobility of protons in the glass increased linearly with increasing its concentration. The conductivity was pro-portional to the square of the proton concentration and the activation energy decreased linerly with increasing logarithm of the proton concentration, And $$\sigma$_0$ and $A_0$ was independent of the proton concentration but not on glass compositions.

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