• 대한화학회지
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• 제16권5호
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• pp.284-289
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• 1972

벤질브로마이드와 여러가지 m-또는 p-핵치환 지오벤즈아미드류와의 반응속도를 전기전도도법으로 측정하였다. 이들 반응에서 전자흡인치환기는 반응속도를 촉진하였고 한편 전자공여치환기는 반응속도를 억제하였다. 이 사실에 부합하는 반응 메카니즘을 고찰하였다. 추가하여 이들 반응에 있어서의 활성화에너지와 활성화엔트로피를 산출하였다.

• 대한수학회지
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• 제49권1호
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• pp.165-185
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• 2012

In this paper, the topological entropy and measure-theoretic entropy for nonautonomous dynamical systems are studied. Some properties of these entropies are given and the relation between them is discussed. Moreover, the bounds of them for several particular nonautonomous systems, such as affine transformations on metrizable groups (especially on the torus) and smooth maps on Riemannian manifolds, are obtained.

• Communications for Statistical Applications and Methods
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• 제21권2호
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• pp.147-160
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• 2014

In this paper, we introduce the exponentiated Weibull-geometric (EWG) distribution which generalizes two-parameter exponentiated Weibull (EW) distribution introduced by Mudholkar et al. (1995). This proposed distribution is obtained by compounding the exponentiated Weibull with geometric distribution. We derive its cumulative distribution function (CDF), hazard function and the density of the order statistics and calculate expressions for its moments and the moments of the order statistics. The hazard function of the EWG distribution can be decreasing, increasing or bathtub-shaped among others. Also, we give expressions for the Renyi and Shannon entropies. The maximum likelihood estimation is obtained by using EM-algorithm (Dempster et al., 1977; McLachlan and Krishnan, 1997). We can obtain the Bayesian estimation by using Gibbs sampler with Metropolis-Hastings algorithm. Also, we give application with real data set to show the flexibility of the EWG distribution. Finally, summary and discussion are mentioned.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제23권3호
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• pp.205-221
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• 2016

We formulate the additive entropy of a natural number in terms of the additive partition function, and show that its multiplicative entropy is directly related to the multiplicative partition function. We give a practical formula for the multiplicative entropy of natural numbers with two prime factors. We use this formula to analyze the comparative density of additive and multiplicative entropy, prove that this density converges to zero as the number tends to infinity, and empirically observe this asymptotic behavior.

• 한국통신학회논문지
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• 제21권6호
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• pp.1390-1397
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• 1996

In this paper, in case of segmenting an image by a fuzzy entropy, an image segmentation algorithm is derived under an extended fuzzy entropy including the probabilistic including the probabilistic information in order to cover the toal uncertainty of information contained in fuzzy sets. By describing the image with fuzzysets, the total uncertainty of a fuzzy set consists of the uncertain information arising from its fuzziness and the uncertain information arising from the randomness in its ordinary set. To optimally segment all the boundary regions in the image, the total entropy function is computed by locally applving the fuzzy and Shannon entropies within the width of the fuzzy regions and the image is segmented withthe global maximum andlocal maximawhich correspond to the boundary regions. Comtional one by detecting theboundary regions more than 5 times.

• 대한화학회지
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• 제8권4호
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• pp.183-187
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• 1964

액체에 관한 hole theory 를 사용하여 여러가지 액체들의 표면장력과 표면 각층의 excess molar sulface entropy 들을 계산하였다. 표면 첫째층의 것은 이상적인 분자가 표면을 형성할 때의 값 Rln2보다 다소 큰 값을 보여주며 액체 내부에 들어감에 따라 점점 줄어들어 저온에서는 셋째층부터 거의 없어진다. 그리고 알곤, 질소, 메탄, 벤젠 및 할로겐들의 표면장력을 계산하여 측정치와 비교하였다.

• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.620-625
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• 2008

The $H_{\infty}$ entropy in $H_{\infty}$ control theory is discussed based on investigating information transmission in continuous-time linear stochastic systems. It is proved that the stabilizing feedback does not change the time-average information transmission between system input and output, and the $H_{\infty}$ entropies of open- and closed-loop stable transfer functions are bounded by mutual information rate between input and output in the open-loop system. Furthermore, a new $H_2$ upper bound for $H_{\infty}$ entropy is introduced with a numerical example. Thus the $H_{\infty}$ entropy of a stable transfer function is sandwiched between $H_2$ norms of the original system and a static feedback system.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3366-3370
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• 2010

The specific rates of solvolysis of t-butyl fluoroformate (1) have been measured at $40.0^{\circ}C$ in 21 pure and binary solvents. These give a satisfactory correlation over the full range of solvents when the extended Grunwald-Winstein equation, with incorporation of the solvent nucleophilicity and the solvent ionizing power, is applied. The actual values are very similar to those obtained in earlier studies of the solvolyses of isopropyl chloroformate and ethyl chlorothioformate in the more ionizing and least nucleophilic solvents, which are believed to proceed by an ionization pathway. The small negative values for the entropies of activation are consistent with the ionization nature of the proposed rate-determining step. These observations are also compared with those previously reported for the corresponding primary and secondary alkyl haloformate esters.

• 대한화학회지
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• 제10권3호
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• pp.136-142
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• 1966

벤젠-시클로핵산 이성분 용액에다 Transient State Theory of Significant Liquid Structure를 확장 적용시켰다. 상태함을 구하고 이것으로부터 계의 전체압, 부분압, 몰부피 그리고 과량의 엔트로피와 같은 열역학적 양을 $303.15^{\circ},\;\313.15^{\circ}$및 $343.15^{\circ}K$에서 계산하였다. 이와 같이 구한 계산치들은 실측치와 대단히 잘 맞았다.

• 약학회지
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• 제33권6호
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• pp.350-360
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• 1989

The conformation and activity of the four benzenesulfonyl analogues of 4-aminobenzene-sulfonamide, 4-aminobenzenesulfonic acid, 4-methylbenzenesulfonamide, and 4-methylbenzenesulfonic acid with antibacterial activity on Staphylococcus aureus were studied using an empirical potential function (ECEPP/2) and the hydration shell model. The conformational energies were minimized from the starting conformations which included possible combinations of torsion angles in each molecule. To understand the hydration effect on the conformation of the molecule in aqueous solution, the hydration free energy of each group was calculated and compared each other. The conformational entropies of low-free-energy coformation of benzenesulfonly analogues were computed by a harmonic approximation. From the correlation of lowest-free-energy conformation of each compound and its antibacterial activity, it was found that the hydration of sulfonyl groups and the substituents are the decisive factors to show antibacterial activities.