• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.3
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• pp.170-177
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• 1981

1,200.deg.C에서의 단조철은 점소성을 나타내며 인발과 압출시 변형영역이 구형수렴형태가 됨을 실험을 통하여 나타난다. 이 변형역 모델로부터 평형방정식을 사용하여 평균 압출 및 인발응력과 정수압을 계산해 낸다. 평균 압출 및 임발응력은 상계 해석 방법에 의한 결과와 비교하여 본 연구의 해석방법의 유효성을 타진하고 정수압은 다른 연구자들의 결과와 비교 검토되며 특히 냉간가공의 경우와 비교 검토 된다. 그 외에 마찰계수, 급형각도와 단면감소율의 영향에 대해서도 논의 된다.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.715-720
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• 1995

DUPIC 핵연료의 제작 조건, 특히 소결 조건에서 필요한 O/M값에 따른 산소포텐샬을 점결함모형을 이용하여 구하였다. 산소포텐샬 값은 순수 우라니아에서보다 크게 나타났고 주요 점결함 형태의 변화로 온도에 따라 엔트로피 값의 변화가 보였다. 연소중 DUPIC핵연료의 산소포텐샬 변화는 핵연료를 닫힌 계로 보고 물질 보존 및 평형법칙을 기초로 하여 구하였다. 산소포텐샬은 초기에 급격히 증가하지만 곧 일정한 값에서 매우 완만히 증가하게 된다. O/M값도 거의 변화가 없는데, 이는 Mo의 완충작용 때문이다. 따라서 초기 Mo의 화학적 형태- 금속 또는 산화물-가 DUPIC핵연료 O/M값 변화에 큰 영향을 미칠 것으로 예측되며 DUPIC핵연료 제작시 소결 조건에 유의할 필요가 있다.

• Journal of fish pathology
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• v.26 no.2
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• pp.65-75
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• 2013

Population growth equation of scuticociliate Miamiensis avidus was obtained from the experimental results of in vitro culture condition to estimate the growth rate and carrying capacity from the growth equation. In addition, intraperitoneal infections into olive flounder Paralichthys olivaceus were carried out into 2 different conditions: different concentrations of M. avidus in same water temperature and same concentration of M. avidus in different water temperatures. Olive flounder mortality was threshold dependent with both the temperature and M. avidus density parameters. In this paper, we propose a mathematical model to study M. avidus growth in olive flounder based upon the interactions between parasite and host. The mathematical model was logistic growth differential equation (1.2). The parameters were found with Matlab program through the Levenberge-Marquardt method. In theorem, equilibrium values between the infected fish population and dead population could found. Our equilibrium points were a stable equilibrium and an unstable equilibrium. From the equation (1.6), it was possible to predict the amount of cumulative mortality of olive flounder along with the time after M. avidus infection.

• 주택과사람들
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• s.197
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• pp.52-55
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• 2006

최근 고분양가 논란이 일고 있는 은평뉴타운의 1지구 A~C공구와 2지구 A공구가 10월 분양에 들어갈 예정이다. 은평뉴타운은 아파트의 외관을 다양화해 일조, 조망, 환기 그리고 입주자의 생활 형태에 맞춘 설계를 계획하고 있다. 리조트형 생태 전원도시를 지향하는 은평뉴타운의 4개 공구별 특장점과 대표적인 4가지 평형에 대해 살펴보았다.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.239-244
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• 1973

Effects of nitrogen sources on free amino acids, and on photosynthsis-respiration equilibrium point of various positional leaf in soybean were investigated in relation to phosphorus sensitivity. The content of free amino acids was highest in ammonium and lowest in urea treated leaves. Glycine, serine, alanine and especially histidine were high in the ammonium treated leaves. Aspartic acid was high in the nitrate treated leaves. Photosynthesis respiration equilibrium point was higher in the sensitive cultivars, and higher with ammonium than with nitrate. The excess ammonium in plant appears to draw out an intermediate metabolite from carbon fixation pathway resulting in photosynthetic inhibition and activate pentoses phosphate pathway and photorespiration. Such phenomena were likely accentuated in phosphorus sensitive variety.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.111-123
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• 2005

A network design model has been proposed. which represents a transportation facility investment decision problem. The model takes the discrete hi-level programming form in which two types of decision makers, government and travelers, are involved. The model is characterized by its ability to address the total social costs occurring in transportation networks and to estimate the equilibrium link volumes in multi-modal networks. Travel time and volume for each link in the multi-modal network are predicted by a joint modal split/traffic assignment model. An efficient solution algorithm has been developed and an illustrative example has been presented.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.254-257
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• 2008

For crystalline slags, of which the viscosity rapidly increases at $T_{cv}$ due to the formation of crystalline phases, the Tcv is affected by measurement conditions. In this study, we investigated the effect of cooling rate, and alumina dissolution on the determination of $T_{cv}$. Using synthetic slag samples based on the composition of Alaska Usibelli slag, $T_{cv}$ were determined under a constant cooling rate of $2^{\circ}C$/min, and under rapid cooling with holding time to allow the slag to reach thermal and rheological equilibrium. The effect of alumina dissolution was investigated using platinum lined crucibles. The constant cooling resulted in lower $T_{cv}$ by $33^{\circ}C$ as compared to the equilibrium measurements. Under $2^{\circ}C$/min cooling, the blocking alumina dissolution resulted in lower $T_{cv}$ by $23^{\circ}C$. When the $T_{cv}$ was measured under $2^{\circ}C$/min cooling using an alumina crucible, therefore, the effects of a constant cooling is somewhat offset by the alumina dissolution effect, and bring the measured value closer to the true value.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.706-713
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• 1994

Isothermal vapor-Liquid equilibrium data have been measured for binary systems MTBE-methanol, MTBE-n-heptane, and methanol-n-heptane at $45^{\circ}C$ and $65^{\circ}C$ by using head space gas chromato-graphy (H.S.G.C). Among these systems a minimum azeotrope was observed in both of MTBE-methanol system and n-heptane-methanol system. Particularly n-heptane-methanol system has a heterogeneous minimum azotrope since it has an immisible region. These equilibrium data were correlated with the excess Gibbs energy model, and the thermodynamic consistency test was also carried out by using Redlich-Kister equation.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.159-164
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• 1967

An exact expression of the titration fraction as a function of the potential is derived for the cases where the coefficients of the both half reactions involved in the titration are homogeneous. It shows that the potential is independent of the concentration of the reagents not only at the equivalence point but also at all titration fractions. The sharpness of the end point detection by potentiometric method is shown to depend not only on the difference of the normal potentials involved but also strongly on the number of electrons transferred in each half reaction. The inflexion point of the potentiometric titration curve is shown to be slightly off from the equivalence point, including the cases where the number of electrons involved are equal. Completeness of the reaction in the course of titration is analyzed, too, mostly in terms of equilibrium constant, thus most of the results are applicable to any type of equilibrium in a single phase with particular relationship of coefficients of chemical equation.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.1
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• pp.1-8
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• 2005

An axisymmetric compressible flow solver accounting for chemical equilibrium has been developed as an analysis tool exclusively suitable for performance prediction and optimum contour design of LRE thrust chamber. By virtue of several features focusing on user-friendliness and effectiveness including automatical grid generation and iterative calculations with changes in design parameters prescribed through only one keyword-type input file, a design engineer can evaluate very fast and easily the influences of various design inputs such as geometrical parameters and operating conditions on propulsive performance. Validations have been carried out for various aspects by detailed comparisons with the result of CEA code, experimental data of JPL nozzle, actual data for two historical engines, and ReTF data for KSR-III.