• Applied Biological Chemistry
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• 제14권1호
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• pp.99-102
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• 1971

Saccharomyces rouxii $T_9$의 생육에 있어서 질소원 및 무기염류의 영향을 실험한 결과는 아래와 같다. (1) 무염배지의 경우 유기질소원으로서는 peptone을 $2.5{\sim}5.0%$ 첨가했을때 균의 생육이 가장 양호하였으며 무기질소원으로서는 $(NH_4)_2HPO_4$를 1.0% 첨가했을때 가장 양호하였다. (2) 20% 식염함유배지의 경우 유기질소원으로서는 yeast ext.를 1.5% 첨가했을때 가장 양호하였으며 무기질소원으로서는 urea를 5% 첨가 했을매 가장 양호하였다. (3) 무기염류로서 $NaNO_3$는 무염배지의 경우 1% 첨가했을때 가장 양호하였으나 20% 또 식염함유배지의 경우에는 26% 첨가했을 때보다 5%첨가했을때 더욱 양호 하였다. (4) $MgSO_4$와 $CaCl_2$는 0.5% 첨가한 경우 무염배지에서 보다도 20% 식염함유 배지에서 더욱 효과가 있었으며 $MgCl_2$는 26% 식염함유배지에 1%첨가 했을때 가장 효과가 있었다.

• 한국주조공학회지
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• 제8권4호
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• pp.453-458
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• 1988

Al-Si alloy powder produced by the gas atomizer showed fine eutectic structure between ${\alpha}-dendrites$, that was grown by coupled growth, and there remained small amount of ${\alpha}$ in Al - 20 wt% Si alloy. The morphology of Si in the eutectic structure was largely influenced by the recalescence caused by solidification latent heat, and that was thought to be due to decrement of the surface energy of Si. In modified eutectic Si by rapid solidification, fine twin about $0.01\;{\mu}m$ was observed and growth direction of eutectic Si was <112>. This fact implied that the growth mechanism of eutectic Si in rapid solidification was related to TPRE mechanism. Due to rapid solidification Si was soluble in ${\alpha}-phase$ in Al - 12.6wt%Si alloy up to about 3.4wt%, and the solubility of Si in ${\alpha}-phase$ reaches the equilibrium solubility stare after 60min, holding when it was held isothermally at $253-296^{\circ}C$.

• 분석과 대안
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• 제4권2호
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• pp.71-102
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• 2020

This study analyzes the effect of demographic changes on economic growth. We use the supply-side output identity to forecast the growth potential of the Korean economy. According to the results, even based on optimistic assumptions and prospects, the economic growth rate is likely to fall drastically starting in 2020. Of course, to maintain growth potential, efforts to increase productivity are necessary. However, given the historical experience of developed countries, it is not clear whether the huge trend of demographic change can be offset by efforts to increase productivity. In the so-called '30-50 club' countries, both labor productivity and growth rate tend to fall after reaching the per capita income of $30,000. The degree of decline in the growth rate is closely related to changes in the working age population and the prime-age workforce. The results are similar when tracking the path of changes in total factor productivities of the economy. When a certain level of income is reached, the increase in total factor productivity also tends to slow down. The ripple effects of rapid changes in demographics will indeed be extensive. The negative impact is likely to be concentrated at a time when the working age population, the prime-age workforce, and the total population shrink simultaneously. Above all, it is necessary to use the government's fiscal space to block the possibility of a rapid fall in the growth rate. In addition, it is important to continuously implement various reform tasks that should be promoted, such as improving the education system and strengthening the social safety net.

• 한국조경학회지
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• 제39권6호
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• pp.110-117
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• 2011

본 연구는 2010년 4월 3일부터 3가지 토양 조성에 따른 섬기린초의 월동 후 생육상태를 측정하였고, 초고-생장시간 생장모형을 개발하고자 하였다. 이를 위해 함수식(Logistic식과 Gompertz식)을 사용하였고, SPSS를 이용하여 비선형 회귀분석을 진행하였다. 섬기린초의 초고-생장시간 생장모형을 통하여 섬기린초 월동 후의 생장과정과 관리방법을 명확하게 파악할 수 있다. 섬기린초의 생육상태 측정치에 의하면, 펄라이트($P_1$)보다는 혼합한 토양($P_2P_1V_1$, $P_1P_2V_1$)의 생육상태가 더 양호하고, 평균초고는 최대 약 2배 정도의 차이가 나타났다. 그리고 섬기린초의 Logistic생장모형과 Gompertz생장모형의 평균결정계수($R^2$)는 0.995, 0.978 순으로 나타났으며, Logistic생장모형의 적합성은 Gompertz생장모형보다 높은 것으로 확인되었다. 또한 섬기린초의 생장모형을 통하여 월동 후의 생장 기간은 3기간으로 나눌 수 있으며, 생장형태는 "비교적 빠른 생장기간---아주 빠른 생장기간---느린 생장기간"으로 구분할 수 있다. 옥상녹화용 섬기린초를 관리할 때 빠른 생장기간에서만 관리하면 섬기린초의 생육상태는 많이 좋아질 것으로 판단된다.

• 한국세라믹학회지
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• 제29권4호
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• pp.305-311
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• 1992

As compared with conventional sintering, rapid heating in microwave system could enhance sinterability and final properties of alumina with a very short sintering time. In this study microwave sintering was performed using zirconia brick as a reaction chamber which was positioned in a 2.45 GHz(700 W) multimode microwave cavity. Microwave-sintered alumina showed high density and smaller grain size than conventionally sintered alumina because the ratio of densification rate/grain growth rate was increased by rapid heating.

• The Korean Journal of Ecology
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• 제1권2호
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• pp.49-56
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• 1977

For the culture the population growth, shell length and spawning seasons of Gomphina veneriformis, and its environmental factors, were investigated at the Jeju coastal regions. from Feburuary, 1975 to March, 1976. The soil movements of the tidal flats where the clams inhabited were relatively rapid during the strong tidal actions. The rate of population growth were rapid from April to September, then became obsure. The relative growth equations of the shell height (SH) and the shell breadth (SB) against the shell length (SL) of the clams were as follows: Changhung : SH=0.751 SL + 0.685, SB=0.448 SL-0.630 Pyoson : SH-0.775 SL - 0.115, SB=0.464 SL-1.008 Hwhason : SH=0.794 SL - 0.923, SB=0.485 SL-1.155 Kwhagzee : SH=0.771 SL - 0.644, SB=0.455 SL-1.049 The meat weight increases of the clams were continued from March to late June, then it decreased sharply up to late August. The spawning of the clams seems to be late from June to Spetember in the regions studied.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2008년도 연합학회학술대회
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• pp.321-338
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• 2008

Information and communication industry, which shows rapid growth rate, is now leading the global economic growth, contributing a ripple effect on general business and economic structure. It is said that information and communication industry enables swift economic growth taking a role as a basic industry of information-oriented society. Especially, rapid technical innovation promotes mutual growth of other related industries and it is technology-intensive. The purpose of this research is to analyze the management efficiency of information and communication industry using DEA method, and finally suggest numerical value for inefficient organizations to improve their efficiency. CCR-I, BCC-I efficiency and RTS(Returns to scale) of 29 companies engaged in information and communication industry was evaluated. With the results, I suggested model companies for benchmarking in information and communication industry. To summarize, 7 companies were selected with CCR-I efficiency rate 1, and 12 companies with BCC-I efficiency rate 1. RTS was finalized with 8 IRS companies, 10 DRS companies, and 11 CRS companies.

• 미생물학회지
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• 제22권3호
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• pp.135-142
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• 1984

The effect of biotin on the growth and sporulation of Bacillus subtilis SNU816 was investigated. When B. subtilis SNU816 was cultured on glucose as a sole carbon source, the growth was retarded markedly and usually ceased at early log phawe. But by addition of biotin to this medium, normal, rapid growth was restored. The growth rate was increased proportionally according to the concentration of exogenous biotin until it reached to 0.05㎍/ml, at which about three fold rapid growth was achieved. Also biotin was required for optimum sporulation for it facilitated the complete utilization of both glucose(Glc) and glutamic acid(Glu). Without biotin in Glc+Glu medium, about 40% of glutamic acid was remained unutilized. The dipicolinic acid content of cells cultured in Glc+Glu medium without biotin was markedly small and sporulation was suppressed before free spore release. Since biotin could be partiallyreplaced by one of TCA cycle intermediates such as oxalacetic acid, citric acid, or glutamic acid in enhancing growth in Glc medium, it was postulated that this strain might have a defect in converting pyruvate to oxalacetate which process is known to be mediated by pyruvate carboxylase that requires biotin as a cofactor.

• 한국해양공학회지
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• 제1권2호
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• pp.93-100
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• 1987

Corrosion fatigue cracking of the austenitic stainless steel(bese metal & heat affected zone by TIG weld) was studied experimentally under the environments of various specific resistance and air. The characteristics of corrosion fatigue crack growth rate and the environmental constants of paris' rule were investigated for SUS 304 weldments in the various specific resistance. The influences of stress intensity factor range and corrosion on the crack growth rate were compared. The characteristics of corrosion fatigue cracking for the weldments were inspected from mechanical, electrochemical and microstructural point of view. Main results obtained are as follows: 1) As the specific resistance decreases, the environmental constant C of paris'rule increases(hence the corrosion fatigue crack growth rate is rapid), but the environmental constant m decreases, so the effect of corrosion to the crack growth rate is more susceptible than thet of stress intensity factor range. 2) As the stress intensity factor range decreases, the corrosion fatigue crack growth rate of heat affected zone is more susceptible than that of the base metal. 3) The corrosion fatigue crack growth rate of the heat affected zone is more rapid than that of the base metal, because of the phenomenon of softening and the less noble potential coused by wedlding heat cycle. 4) The corrosion fatigue cracking of SUS 304 weldment appears transgranular fracture.

• Journal of Preventive Medicine and Public Health
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• 제11권1호
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• pp.31-40
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• 1978

저자는 1970년부터 1975년까지 6 년갑에 걸쳐 부산지역 국민학교 학생들의 신체발육상태를 평가하고져 무작위로 추출한 부산시 모 국민학교 학생 656명(남 374, 여 282)을 대상으로 그들의 실제 신체체격 측정을 통하여 과거 6 년 동안의 신체발육상태를 조사 분석하여 다음의 결론을 얻었다. (1) 신장의 연간 최대성장연령은 남자$7{\sim}8$세 (5.9cm), 여자 $10{\sim}11$세 (6.5cm)이었고 남녀 신장발육곡선은 $10{\sim}11$세에서 서로 교차하였다. (2) 체중의 연간 최대성장연령은 남자 $9{\sim}10$세(3.1kg), 여자 $10{\sim}11$세 (3.9kg)이었고 남녀체중발육 곡선은 $10{\sim}11$세에서 서로 교차하였다. (3) 흉위의 연간 최대성장연령은 남자 $8{\sim}9$세(3.1cm), 여자 $9{\sim}10$세 (2.9cm)이었고 전자와는 달리 남녀 융위발육곡선은 서로 교차하지 않았다. 4. 좌고의 연간 최대성장연령은 남녀 모두 $6{\sim}7$세 (남 3.3cm, 여 3.4cm)이었고 남너 좌고발육곡선은 $8{\sim}9$세에서 서로 교차하였다. (5) 각 지역간의 비교에는 각각의 신체계측치를 체격종합치 (Physical Integrated Ualue)로서 서로 비교하는 것이 매우 간편하고 바람직 하였으며 한국소아 신체표준발육치에 대한 부산지역 국민학교 학동들의 체격종합치 (Physical Integrated Value)는 남여 각각 신장 +0.30, +0.29, 체중 +0.33, +0.35 흉위 +0.65, +0.57, 좌고 +0.10, +0.20으로 서울을 제외한 타지역 (대구, 대전, 농촌지역)에 비하여 비교적 우수하였다.