• 자원환경지질
• /
• 제30권4호
• /
• pp.321-325
• /
• 1997

In this paper an attempt is made to explain some of the factors controlling oxygen and hydrogen isotopic variations of precipitation in Pohang by analysing the IAEA data (1961~1976) through statistical correlations and trend observations. During this period, the values of ${\delta}^{18}O$ and D varied widely from -17.80 to +0.07‰, and from -131.9 to +7.7‰, respectively, and fall along a local meteoric water line defined by ${\delta}D=(8.05{\pm}0.32)$ ${\delta}^{18}O+(12.72{\pm}2.44)$ (n=108, ${\gamma}^2=0.86$). The ${\delta}^{18}O$ and ${\delta}D$ values of the precipitation appear to be little dependent on temperature. Although the amount effect is clearly shown in summer precipitation of 1963 and 1965, the isotopic composition of summer precipitation seems not to be greatly dependent on the amount of precipitation.

• 대한수학회보
• /
• 제20권1호
• /
• pp.31-36
• /
• 1983

Let R be a commutative ring with 1, and A a unitary commutative R-algebra. By a derivation module of A, we mean a pair (M, d), where M is an A-module and d: A.rarw.M and R-derivation, i.e., d is an R-linear mapping such that d(ab)=a)db)+b(da). A derivation module homomorphism f:(M,d).rarw.(N, .delta.) is an A-homomorphism f:M.rarw.N such that f.d=.delta.. A derivation module of A, (U, d), there exists a unique derivation module homomorphism f:(U, d).rarw.(M,.delta.). In fact, a universal derivation module of A exists in the category of derivation modules of A, and is unique up to unique derivation module isomorphisms [2, pp. 101]. When (U,d) is a universal derivation module of R-algebra A, the A-module U is denoted by U(A/R). For out convenience, U(A/R) will also be called a universal derivation module of A, and d the R-derivation corresponding to U(A/R).

• 자원환경지질
• /
• 제35권2호
• /
• pp.113-120
• /
• 2002

한강 수계분지내의 하천수의 산소 및 수소 동위원소 조성은 $\delta$D=6.6delta$$^{18}$ O-7.4,로 순환수선($\delta$D=8$\delta$$^{18}$ O+10)과 차이를 나타내고 있다. 이는 한강수계 분지내의 지역적 기상조건과 증발 영향 때문으로 해석된다. 한강 하천수의 5150과 5D 값은 각각 -8.2~-10p77(평균 -9.17f7)과 -60~-96%e(평균 -69f77)이다. 그리고 남한강 하턴수치 평균$\delta$$^{18}$ O 와$^{18}$ O값은 -9.3$\textperthousand$과 -69$\textperthousand$로 북한강 하천수의 -9.2$\textperthousand$와 -69$\textperthousand$값보다 무거운 산소와 수소 동위원소비가 결핍되어 있다. 이는 남한강 하천수에 탄산염 기원과 황화광물 기원의 황산염의 무거운 산소의 유입과 위도 효과를 받고 있음에도 불구하고 집수지의 고도 효과의 영향을 더 많이 받기 때문으로 해석된다. 등위원소 자료에서 계산된 한강본류에서의 남한강과 북한강 하천수의 혼합비율은 약 6 : 4로 남한강 하천수의 영향이 한강 본류 하천수에 크게 영향을 주고 있다.

• 한국작물학회지
• /
• 제30권3호
• /
• pp.217-222
• /
• 1985

초형이 다른 3종의 수도 Isogenic line(Open-Spread- 및 Broom-type)을 5수준의 이앙밀도(47.62, 22.22, 15.15, 15.11 및 8.33주/$m^2$)와 4수준의 시비조건(증비, 보비, 감비 및 무비)에 공시하여 얻은 수량자료를 Multiple regression polynomial 수식으로 고정하고 편미분하여 밀도와 시비및 밀도$\times$시비의 작용력을 해석하였다. 그 결과는 다음과 갈다. 1. 소식조건하에서의 밀도변동에 따른 수량 반응은 Broom-type이 가장 높고 예민하였다(도 1). 2. 이앙밀도의 작용력〔$\delta$f(D, F)/$\delta$D〕은 Open-, 및 Spread-type이 다비에서 높아지는 대신에Broom-type은 시비와 관계없이 소식 및 밀식에서 높은 경향이었다.(도 2). 3. 시비율의 작용력 〔$\delta$f(D, F)/$\delta$D〕은 0~1000kg/10a 범위로서 Open- 및 Spread-type에서는 밀식조건하에서 높았으나 Broom-type에서는 소식조건하에서 소비 및 다비의 작용력이 큰 경향이었다(도 3). 4. Broom-type의 소식조건하에서 밀도$\times$시비의 상호작용력 〔$\delta$$^2$F(D, F)/$\delta$D$\delta$F〕은 음성을 나타내었고, Open- 및 Spread-type은 표준 및 밀식과 증비 조건에서 양성을 나타내었다(도 4). 5. $m^2$당 11~14주의 소식조건하에서 추정되는 소요시비수준은 Open-type 이 1.3~1.5배비인 반면에 Broom-type은 1.5배비 이상의 수준인 것으로 판단되었다. 6. 소식에 의한 이앙노동의 생력화를 위해서는 다비수용이 가능한 Broom-type의 연구가 필요할 것으로 해석이 된다.

• 한국안광학회지
• /
• 제19권3호
• /
• pp.345-351
• /
• 2014

목적: 각 사위 그룹에서 가입렌즈에 따른 조절반응량과 근거리 수평사위도의 변화를 측정하여 자극 AC/A비와 반응 AC/A비를 조사하였다. 이에 자극 AC/A비와 반응 AC/A비를 비교 분석하여 임상에서의 양안시 검사 및 처방시에 유용한 자료로 제시하고자 한다. 방법: 평균 만 $20.89{\pm}1.92$세, 81명을 대상으로 주시거리 40 cm에서 개방형 자동굴절계(Nvision-K 5001, Shin nippon)와 수정된 토링톤 시표(MIM card; Muscle Imbalance Measure card, Bernell)를 이용하여 양안시 상태에서 조절반응량과 근거리 수평사위도를 측정하였다. 그리고 측정된 값을 토대로 자극 AC/A비와 반응 AC/A비를 경사 AC/A법으로 계산하였다. 결과: 주시거리 40 cm에서 조절반응량은 외사위 그룹이 $1.92{\pm}0.26$ D로 가장 크고, 정위 그룹 $1.72{\pm}0.26$ D, 내사위 그룹 $1.62{\pm}0.42$ D 순으로 작아졌고, 근거리 수평사위도의 변화폭은 내사위 그룹이 $23.24{\Delta}$로 가장 크고, 정위 그룹 $19.76{\Delta}$, 외사위 그룹 $15.14{\Delta}$ 순으로 작게 나타났다. 가입렌즈에 따른 자극 AC/A비와 반응 AC/A비의 차이는 외사위 그룹에서는 -2.00 D 렌즈를 가입하였을 때, $1.72{\Delta}/D$로 가장 컸고 내사위 그룹에서는 +1.00 D 렌즈를 가입하였을 때 $3.43{\Delta}/D$로 가장 크게 나타났다. 외사위 그룹에서 -2.00 D, -1.00 D 렌즈를 가입하였을 때, 내사위 그룹에서는 +3.00 D, +2.00 D, +1.00 D, -1.00 D 렌즈를 가입하였을 때 각각 통계적으로 유의한 차이를 보였다. 결론: 자극 AC/A비와 반응 AC/A비를 비교하였을 때, 외사위 그룹에서는 (-) 렌즈를 가입하였을 때의 차이가 더 크고, 내사위 그룹에서는 (+) 렌즈를 가입하였을 때의 차이가 더 크게 나타났다. 또한 내사위 그룹의 자극 AC/A비와 반응 AC/A비의 차이가 외사위 그룹의 차이보다 더 크게 나타났다.

• 한국해양공학회지
• /
• 제7권2호
• /
• pp.131-140
• /
• 1993

To study the corrosion fatigue begavior of T.M.C.P. steel, the rotary bending fatigue test with the change of concentration of NaCl solution was carried out. Fatigue life in the corrosion environment is decreased markedly in comparision with that in the air. Fatigue limit in the air was about 225 MPa. In case of 3.5% NaCl solution fatigue life could be expressed as .sigma./sub f/=10,392 * (N/sub f/)/sup -o.2923 . According to the paris's rule, crack growth rates could be expressed as da/dN=2.62.*10/sup -7/ .DELTA. K/sup 1.09/(3.5% NaCl solution), da/dN=1.95 *10/sup -7 .DELTA. K/sup 1.05/(1% NaCl solution), da/dN=2.62 * 10/sup -7/.DELTA./sup 0.72/(0.01% NaCl solution) with da/dN expressed in mm/cycle and .DELTA.K in MPa.GAMMA.m. The crack growth rate in the corrosion environment was highest under 3.5% NaCl solution.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권9호
• /
• pp.650-656
• /
• 2004

This paper presents block and timing diagrams of the DWA(data weighted averaging) to optimize a feedback time delay of the sigma-delta modulator. Through the Matlab modeling, the optimized coefficients of the integrators are obtained to design the modulator. And then the fully differential SC integrators, feedback DAC, 9-level quantizer, and DWA are designed by considering the nonideal characteristics of the modulator. The designed second-order multibit modulator is fabricated in a 0.35$\mu\textrm{m}$ CMOS process. The designed modulator achieves 73dB signal-to-noise ratio and 72dB dynamic range at 1.2Vp-p 585kHz input singal and 52.8MHz sampling frequency.

• Bulletin of the Korean Chemical Society
• /
• 제31권4호
• /
• pp.874-880
• /
• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권5호
• /
• pp.10-19
• /
• 2012

The aim of this study was to examine chemical and isotopic compositions of groundwater and lake water near an area contaminated by petroleum and to evaluate influence of petroleum on them during the period from March to August 2011. In dry season, $Ca^{2+}$ and $SO{_4}^{2-}$ were dominant in the groundwater and lake water and $Ca^{2+}$ and $HCO{_3}^-$ were significant in wet season. ${\delta}^{18}O$ and ${\delta}D$ of the groundwater and lake water were plotted near LMWL (${\delta}D=8.06{\delta}^{18}O+12.5$). ${\delta}^{18}O$ and ${\delta}D$ of the lake water did not show seasonal variation. However, ${\delta}^{18}O$ and ${\delta}D$ of the groundwater were enriched in wet season compared with those in dry season because of influence of small ponds around wells where evaporation losses were slightly experienced. Redox condition of most lake water was oxidation environment in contact with the atmosphere during the study period. However, redox condition of groundwater was transitional environment in dry season and oxidation environment in wet season because of influence of contaminant such as petroleum. In some groundwater, the concentrations of $NO{_3}^-$ in some groundwater were less than 1 mg/L because of denitrification. Also, $NO{_3}^-$ showed positive correlation with $SO{_4}^{2-}$ and weak negative correlation with $HCO{_3}^-$, because of influence of denitrification.

• 대한수학회지
• /
• 제15권1호
• /
• pp.39-57
• /
• 1978

It is given in the Lecture Note [1] of Berger, Gauduchon and Mazet that, if ${\pi}$n: (${\tilde{M}}$, ${\tilde{g}}$)${\rightarrow}$(${\tilde{M}}$, ${\tilde{g}}$) is a Riemannian submersion with totally geodesic fibers, ${\Delta}$ and ${\tilde{\Delta}}$ are Laplace operators on (${\tilde{M}}$, ${\tilde{g}}$) and (M, g) respectively and f is an eigenfunction of ${\Delta}$, then its lift $f^L$ is also an eigenfunction of ${\tilde{\Delta}}$ with the common eigenvalue. But such a simple relation does not hold for an eigenform of the Laplace-Beltrami operator ${\Delta}=d{\delta}+{\delta}d$. If ${\omega}$ is an eigenform of ${\Delta}$ and ${\omega}^L$ is the horizontal lift of ${\omega}$, ${\omega}^L$ is not in genera an eigenform of the Laplace-Beltrami operator ${\tilde{\Delta}}$ of (${\tilde{M}}$, ${\tilde{g}}$). The present author has obtained a set of formulas which gives the relation between ${\tilde{\Delta}}{\omega}^L$ and ${\Delta}{\omega}$ in another paper [7]. In the present paper a Sasakian submersion is treated. A Sasakian manifold (${\tilde{M}}$, ${\tilde{g}}$, ${\tilde{\xi}}$) considered in this paper is such a one which admits a Riemannian submersion where the base manifold is a Kaehler manifold (M, g, J) and the fibers are geodesics generated by the unit Killing vector field ${\tilde{\xi}}$. Then the submersion is called a Sasakian submersion. If ${\omega}$ is a eigenform of ${\Delta}$ on (M, g, J) and its lift ${\omega}^L$ is an eigenform of ${\tilde{\Delta}}$ on (${\tilde{M}}$, ${\tilde{g}}$, ${\tilde{\xi}}$), then ${\omega}$ is called an eigenform of the first kind. We define a relative eigenform of ${\tilde{\Delta}}$. If the lift ${\omega}^L$ of an eigenform ${\omega}$ of ${\Delta}$ is a relative eigenform of ${\tilde{\Delta}}$ we call ${\omega}$ an eigenform of the second kind. Such objects are studied.