• The Pure and Applied Mathematics
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• v.15 no.4
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• pp.387-392
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• 2008

In this note, an alternative proof and extensions are provided for the following conclusions in [6, Theorem 1 and Theorem 3]: The functions $\frac1{x^2}-\frac{e^{-x}}{(1-e^{-x})^2}\;and\;\frac1{t}-\frac1{e^t-1}$ are decreasing in (0, ${\infty}$) and the function $\frac{t}{e^{at}-e^{(a-1)t}}$ for a $a{\in}\mathbb{R}\;and\;t\;{\in}\;(0,\;{\infty})$ is logarithmically concave.

• Journal of the Korean Mathematical Society
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• v.32 no.4
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• pp.739-751
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• 1995

Let ${X(t) : 0 \leq t < \infty}$ be an almost surely continuous Gaussian process with X(0) = 0, E{X(t)} = 0 and stationary increments $E{X(t) - X(s)}^2 = \sigma^2($\mid$t - s$\mid$)$, where $\sigma(y)$ is a function of $y \geq 0(e.g., if {X(t);0 \leq t < \infty}$ is a standard Wiener process, then $\sigma(t) = \sqrt{t})$. Assume that $\sigma(t), t > 0$, is a nondecreasing continuous, regularly varying function at infinity with exponent $\gamma$ for some $0 < \gamma < 1$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.191-196
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• 1996

Age growth and spawning period of Enedrias nebulosus were estimated based on otoliths taken from a total of 255 fish samples of E. nebulosus, which were caught in the costal waters of $Kod\v{o}kto$ near Pusan from November 1990 to October 1991. Marginal increment analysis indicates that annuli in E. nebulosus are formed in December. Spawning period was estimated to be November to January, with a peak in December. The von Bertalanffy growth equations were expressed as follows: $L_t=33.64(1-e^{-0.1357(t+2.6853)})$ and $W_t=414.11(1-e^{-0.1357(t+2.6853)})^{3.9745}$, Where $L_t$, is total length in cm, $W_t$, is total weight in g and t is age in year.

• Journal of the Korean Mathematical Society
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• v.49 no.3
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• pp.641-658
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• 2012

The goal of this paper is to develop a nonlinear observer-based control strategy for a multi-variables continuous stirred tank reactor (CSTR). A new robust nonlinear observer is constructed to estimate the whole process state variables. The observer is coupled with a nonlinear controller, designed based on the input-output linearization for controlling the concentration and reactor temperature. The closed loop system is shown to be globally asymptotically stable based on Lyapunov arguments. Finally, computer simulations are developed for showing the performance of the proposed controller.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.259-269
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• 2007

This study was compared the effect of shelf-life and DHA accumulation in chicken meat from broilers fed experimental diets for two weeks($21{\sim}35$ days) of growers. Two hundred-ten male Ross broilers, 1 day of age, were randomly allocated to seven treatment groups. Experimental diets were assigned to each of the seven groups: control diet containing tallow, T1 with 1.00% fish oil, T2 with 2.00% fish oil, T3 with 2.00% fish oil, 200 ppm vitamin E and 200 ppm vitamin C, T4 with 2.00% fish oil and 200 ppm vitamin C, T5 with 2.00% fish oil and 200 ppm vitamin E, and T6 with 3.00% fish oil. The levels of DHA in chicken meat was the highest in T6, and T1 in breast muscle and thigh muscle with skin was higher than that of $T2{\sim}T5,\;T2{\sim}T5$ in raw chicken meat and wing with skin was about two-fold higher than that of T1. The contents of DHA in chicken meat according to storage days were significantly reduced to 42.30%, 49.38% and 48.51% in T1, T2 and T6, respectively, and this decrease was higher than that of T3, T4 and T5 (p<0.05). Particularly, the rate of reduction of DHA was the lowest in the T3 and T5, which were the lowest in TBARS(thiobarbituric acid reactive substances). TBARS increased in the order of T6, T2 and T1, but reduced in the order of T3, T5 and T4 according to storage days, and there was a significant difference among the treatment groups (p<0.05).

• Bulletin of the Korean Mathematical Society
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• v.51 no.2
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• pp.357-371
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• 2014

We shall show that the Riesz idempotent $E_{\lambda}$ of every *-paranormal operator T on a complex Hilbert space H with respect to each isolated point ${\lambda}$ of its spectrum ${\sigma}(T)$ is self-adjoint and satisfies $E_{\lambda}\mathcal{H}=ker(T-{\lambda})= ker(T-{\lambda})^*$. Moreover, Weyl's theorem holds for *-paranormal operators and more general for operators T satisfying the norm condition $||Tx||^n{\leq}||T^nx||\,||x||^{n-1}$ for all $x{\in}\mathcal{H}$. Finally, for this more general class of operators we find a sufficient condition such that $E_{\lambda}\mathcal{H}=ker(T-{\lambda})= ker(T-{\lambda})^*$ holds.

• Journal of the Korean Chemical Society
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• v.26 no.6
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• pp.396-402
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• 1982

Bacteriophage T4 tRNA processing in E. coli mutant strains defective in RNase Ⅲ, RNase E$^-$, and RNase P, respectively, singly or in combinations, was investigated. In $RNase E^- strains, a RNA band, which would be referred as 9S RNA, accumulates, while in RNase$ P^-$ strains, lower band of 6S double band is accumulated. In RNase III$^-$ strains, the production of tRAN$^{Gln}$ coded by T4 tRNA gene cluster, is severely depressed and also production of species 1 RNA, which is coded by T4 DNA but not by the tRNA gene cluster, is in somewhat depressed amounts; on the other hand, at the same time, an upper band of 6S double bands, coded by T4 tRNA gene cluster, is accumulated in rather greater amounts as compared to the RNase $^+$ strain. The upper band RNA of the 6S double band, however, does not appear to be a precursor to the tRNA$^{Gln}$. The present work points to the lack of evidence for an essential cleavage role of RNase Ⅲ, although there must be a role for the RNase Ⅲ in the T4 tRNA processing.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.359-364
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• 2013

This study was conducted to develop a model to estimate crop leaf surface temperature. The results were as following; A definition for the daily time based on elapsed time from the midnight (00:00) as "E&E time" with the unit of Kmin. was suggested. The model to estimate the scaled temperature ($T^*e$) of crop leaf surface temperature by scale factor ($T^*$) according to the "E&E time : Kmin."(X) was developed as eq. (1) $T^*e=0.5{\cdot}sin(X+780)+0.5$ (2) $T^*=(Tx-Tn)/(Tm-Tn)$, Tx : Daily leaf temperature, Tm : Daily maximum leaf temperature, Tn : Daily minimum leaf temperature. Relative sensitivity of the measured temperature compared to the estimated temperature of red pepper, soybean and persimmon was 1.078, 1.033 and 0.973, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.468-471
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• 2004

Tocotrienol $(T_3)$ and tocopherol (T) are well-known antioxidant vitamin E isomers that are enriched in rice bran, most of which is removed during polishing process. To verify the polishing-dependent fractional content of tocotrienol and tocopherol, harvested brown rice of 4 cultivars were polished by 4.0, 6.4, 8.0, 9.6, and $12\%$ (w/w) and resultant bran powder and rice were used for $T_3$ and T analysis. Polishing degree affected bran $T_3$ content in that bran polished by $6.4\%$ exhibited highest $T_3$ content compared to other polishing degrees except in cv. Chucheongbyeo which showed similar $T_3$ content from 4.0 to $8.0\%$ polishing. In case of tocopherol, bran polished by $8.0\%$ exhibited highest T content in all tested cultivars. In general, $T_3$ distributed in higher quantity in exterior i.e., in less polished bran, while T showed relatively less decrease with enhanced polishing degree. Consequently, total vitamin E content in bran as calculated by the summation of $T_3$ and T became less dependent on polishing degree in that bran polished between 6.4 to $9.6\%$ exhibited no statistical differences. The rice of cv. Chuchongbyeo, remained after polishing, exhibited similar vitamin E content up to $6.4\%$ polishing, above which significant vit E loss could be observed. These results suggest that polishing less than $6.4\%$ is desirable to minimize the loss of tocotrienols and tocopherols during polishing.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.3
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• pp.72-82
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• 2003

인터넷의 사용이 폭발적으로 증가함으로 인해 다양한 서비스들의 욕구가 있고 그 중에서도 VoIP가 대표적인 예이다. ITU-T의 Study Group12에서 QoS (Quality of Service)에 관한 연구를 진행하고 있다. 그 중에서도 품질평가 방법에서 전송계획을 위한 G,107의 E-model을 PSTN에서 IP네트워크로 적용하는 연구를 진행하고 있다. VoIP의 QoS문제점을 분석하고 E-model에서 개선되어야 할 파라미터들을 확인하고, 이를 위한 ITU-T의 개선동향을 살펴봄으로써 앞으로의 E-model이 나아가야 할 방향에 대해서 기술하였다.