• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.383-383
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• 2022

기존 큰 지진을 대상으로 한 많은 연구결과들을 살펴보면, 큰 지진이 발생하기 전에 토양 속에 존재하는 다양한 인자들 중에 라돈(²²²Rn, 반감기=3.82일) 농도가 비정상적으로 증가하는 현상을 나타낸다. 이러한 결과들은 라돈발생의 경향성을 분석한다면, 지진발생에 대한 전조증상이나 예측이 가능함을 나타낸다. 본 연구에서는 포항지역을 중심으로 지진발생에 대한 전조증상이나 모니터링을 분석하기 위해 지하수 관측소에 설치된 라돈 관측기기에서 라돈 관측자료를 수집하고 이를 활용하는 연구를 수행하였다. 라돈 관측자료 기간은 2019년 11월부터 2020년 9월까지의 자료이며, 라돈인자 뿐만 아니라 지하수위, 강수량, 수온인자를 같이 분석하였으며, 동일기간 동안 발생한 진도 2 이상의 지진사례 6개(E1(M_L 3.5): 2019.12.30.; E2(M_L 3.2): 2020.01.30.; E3(M_L 2.4): 2020.02.09.; E4(M_L 2.7): 2020.02.16.; E5(M_L 2.8): 2020.05.27.; E6(M_L 2.1): 2020.09.22.)를 대상으로 하였다. 지진발생의 전조증상이 나타나는 지역을 분석하기 위해 Dobrovolsky radius values (Dobrovolsky et al., 1979)와 Harversine 관계식을 적용하였다. 적용결과, 시간적 분석에서 라돈의 증감 경향성이 지진발생의 전조증상과 유의미한 상관성이 있음을 확인하였으며, 공간적인 분석에서도 유의미하지는 않으나 상관성이 나타났다. 그 외 지하수위는 상관성이 어느 정도 나타났으나 강수량은 유의미한 결과를 나타내지는 않았다. 따라서 라돈을 활용한다면 지진발생의 전조증상을 시공간적으로 파악할 수 있음을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.634-639
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• 2003

It has been studied the flow near a rotating disk with surface topography. The system Ekman number is assumed very small, i.e., $E[{\equiv}\frac{\nu}{{\Omega}^{\ast}L^{\ast2}}]<<1$ in which $L^{\ast}$ denotes a disk radius, ${\nu}$ kinematic viscosity of the fluid and ${\Omega}^{\ast}$ angular velocity of the basic state. Disk surface has a sinusoidal topographic variation along radial coordinate, i.e., $z={\delta}cos(2{\pi}{\omega}r)$, where ${\delta}$ and ${\omega}$ are, respectively, nondimensional amplitude and wave number of the disk surface. Analytic solutions, being useful over the parametric ranges of ${\delta}{\sim}O$( $E^{1/2}$ ) and ${\omega}{\leq}O$ ( $E^{1/2}$ ), are secured in a series-function form of Fourier-Bessel type. An asymptotic behavior, when $E{\rightarrow}0$, is clarified as : for a disk with surface roughness, in contrast to the case of a flat disk, the azimuthal velocity increases in magnitude, together with the thickening boundary layer. The radial velocity, however, decreases in magnitude as the amplitude of surface waviness increases. Consequently, the overall Ekman pumping at the edge of the boundary layer remains unchanged, maintaining the constant value equal to that of the flat disk.

• 한국패류학회지
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• 제17권1호
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• pp.7-12
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• 2001

전라남도 광양시 송도 주변해역에서 2000년 12월에 형망에 의해 채집한 농조개의 연령과 성장을 조사하였다. 연령형질은 패각을 사용하였으며, 윤문은 패각에 나타난 불투명대에서 투명대로 이행하는 경계로 하였다. 출현한 개체의 각장은 13.1-44.2mm이었고, 평균은 19.6mm이었으며, 연령은 2세까지 출현하였다. 각장 (SL) 과 각고 (SH) 간의 상대성장은 SL = 0.2105 ＋ 1.7569 $\times$ SH이었고, 각장 (SL)과 전중 (TW) 간의 상대성장은 TW = 2.5824$\times$ $10^{-4}$ $\times$ S $L^{2.6769}$이었다. Von Bertalanffy 성장식은 $L_{t}$ = 81.46(1-e $^{-0}$.20(t+1.19)/), $W_{t}$ = 33.68(1-e $^{0.20(t+1.19)}$)$^{2.6769}$ 추정되었으며, 극한 각장 ( $L_{\infty}$) 은 81.46 mm, 성장계수 (K) 0.20/year 이었다. 0.20/year 이었다..

• 한국수산과학회지
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• 제45권3호
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• pp.246-252
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• 2012

The age and growth of the blackthroat seaperch Doederleinia berycoides was investigated based on samples captured in the southern seas of Korea from January to December, 2006. Age was estimated by analyzing otolith growth rings. The spawning period was extrapolated from August to November based on monthly changes in the gonad somatic index. The relationship between total length and otolith radius was analyzed separately for each sex with TL=-15.6174+10.3274R for females and TL=-4.4083+7.0749R for males. From the parameters calculated using average total length and weight when the year ring was formed, the growth of D. berycoides was expressed by von Bertalanffy growth equations as $L_t=34.71(1-e^{-0.2557(t+0.2078)})$, $W_t=713.85(1-e^{-0.2557(t+0.2078)})^{3.1972}$ for females, $L_t=27.37(1-e^{-0.3388(t+0.7362)})$, $W_t=353.91(1-e^{-0.3388(t+0.7362)})^{3.1647}$ for males, and $L_t=34.20(1-e^{-0.2530(t+0.2871)})$, $W_t=674.10(1-e^{-0.2530(t+0.2871)})^{3.1171}$ for pooled sexes, where L is total length at age t.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.323-336
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• 2004

We consider the application of complex variable method to elastic problem and investigate the nonlinear effect of finite torsion of a compressible elastic composite layer. We obtain that as a result of finite deformation approach, a tube subjected to torsion decreases in radius giving rise to a “hold effect”.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.381-385
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• 1999

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in a polymerase chain reaction. Taq DNA polymerase has a domain at the amino terminus (residues 1 to 290) that has 5'-3' exonuclease activity and a domain at the C-terminus that catalyzes the polymerase reaction. Taq DNA polymerase is classified into the Pol I family, which is represented by E. coli DNA polymerase I. The alignment of amino acid sequences for the 5'-3' exonuclease domains of the Pol I family DNA polymerases shows ten highly conserved carboxylic amino acids. Crystallographic studies suggested that six of the carboxylic amino acids are clustered within a 7 $\AA$ radius by chelating three metal ions in the active site. Those six carboxylic residues are mutagenized to alanines in order to better understand their function. All six carboxylic residues, Asp l8, Glu1l7, Asp1l9, Asp120, Asp142, and Aspl44, are crucial for catalysis of 5'-3' exonuclease.

• 한국소음진동공학회논문집
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• 제11권5호
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• pp.89-100
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• 2001

The Ritz method Is applied In a three-dimensional (3-D) analysis to obtain accurate frequencies for thick. linearly tapered. annular plates. The method is formulated for annular plates haying any combination of free or fixed boundaries at both Inner and outer edges. Admissible functions for the three displacement components are chosen as trigonometric functions in the circumferential co-ordinate. and a1gebraic polynomials in the radial and thickness co-ordinates. Upper bound convergence of the non-dimensional frequencies to the exact values within at least four significant figures is demonstrated. Comparisons of results for annular plates with linearly varying thickness are made with ones obtained by others using 2-D classical thin place theory. Extensive and accurate ( four significant figures ) frequencies are presented 7or completely free. thick, linearly tapered annular plates haying ratios of average place thickness to difference between outer radius (a) and inner radius (b) radios (h$_{m}$/L) of 0.1 and 0.2 for b/L=0.2 and 0.5. All 3-D modes are included in the analyses : e.g., flexural, thickness-shear. In-plane stretching, and torsional. Because frequency data liven is exact 7o a\ulcorner least four digits. It is benchmark data against which the results from other methods (e.g.. 2-D 7hick plate theory, finite element methods. finite difference methods) and may be compared. Throughout this work, Poisson\`s ratio $\upsilon$ is fixed at 0.3 for numerical calculations.s.

• 한국환경과학회지
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• 제30권8호
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• pp.685-691
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• 2021

This study aimed to find a suitable size and a seedling raising stage for growing cuttings of Euonymus fortunei 'Emerald and Gold' using plug trays. The experimental method, involved cutting two nodes from a solitary branch of E. fortunei 'Emerald and Gold', and the use of 32 (143 mL/cell), 50 (70 mL/cell), 105 (18 mL/cell), 200 (13 mL/cell) plug trays. The cuttings were transplanted to trays after they were filled with a universal horticultural medium. To compare the growths, plant heights, the numbers of leaves, longest root lengths, thickness/radius ratios, dry weights, and fresh weights were measured from July to October, and statistical analyses were performed using both the two-way repeated-measures analysis of variance (ANOVA) and Tukey's post-test. The results confirmed that the size of the plug tray and the seedling raising stage had a significant effect on the growth of E. fortunei 'Emerald and Gold.' In addition, the overall growth was high and the change in growth was relatively rapid in districts 50 and 105. Therefore, it can be considered appropriate to use 50 and 105 trays when growing cuttings of E. fortunei 'Emerald and Gold' on plug trays.

• Macromolecular Research
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• 제16권1호
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• pp.51-56
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• 2008

Spherical micelles of poly(styrene-b-isoprene) (SI) diblock copolymers in selective solvents have been reported to pack onto either face-centered cubic (fcc) or body-centered cubic (bcc) lattices. The selection rule for fcc and bcc lattices has been understood in terms of the intermicellar potentials, and they have been quantified using the ratio of the corona layer thickness to the core radius, $L/R_c$, as suggested by McConnell and Gast. In order to test the validity of the McConnell-Gast criterion, this study compared the $L/R_c$ values from various solutions i.e. nine SI copolymers in several different selective solvents. The McConnell-Gast criterion was not found to be a determining factor, even though it could explain the fcc/bcc selection qualitatively. From the phase diagrams, the transition between fcc and bcc phases was also considered as a function of concentration and temperature, and their physical mechanisms are discussed based on the recent mean-field calculation reported by Grason.

• 한국광학회지
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• 제4권1호
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• pp.9-14
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• 1993

Amplitude filter와 phase filter가 결합된 CFAP(Combined Filter of Amplitude and Phase)의 결상 특성을 조사하기 위해 Bessel beam을 도입하였다. 이 논문에서는 무수차계와 수차를 포함하는 광학계에 대한 PSF와 encircled energy(E), transmission ratio(TR), gain(G)을 Bessel beam의 node수에 따라 계산하였다. 이 결과 Bessel beam은 amplitude filter와 다른 PSF 특성을 보였으며, 또한 구면수차가 포함된 경우 compensating effect가 크게 나타났다. 특히 Bessel beam의 central spot의 size가 Airy disk 반경보다 적게 나타나므로, 고집적 반도체 소자 제작에 이용가능하리라 생각된다.