• Journal of Korea Foundry Society
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• v.29 no.6
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• pp.270-276
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• 2009

After casting button-type small ingots of ternary Fe-Mn-S alloys which had three different Mn/S ratios (1, 5 and 70) in a vacuum arc furnace, the effect of the ratio on the sulfide formation was investigated. In case of the Mn/S ratio of 1, if alloy composition was located in an iron-rich corner on a Fe-Mn-S ternary phase diagram, only duplex MnS-FeS sulfide films were observed in the grain boundary. If the alloy composition was located in the miscibility gap area of the phase diagram, primary globular dendritic sulfides and dendritic sulfide slags were generated within the grain and tubular monotectic sulfides were also detected in the grain boundary. When the Mn/S ratio was 5, if the alloy composition was in the iron-rich corner, only bead-like sulfides were generated. On the other hand, if the composition was in the miscibility gap area, globular dendritic sulfides and dendritic sulfide slags were generated in the form of primary sulfide inclusions and rod-like eutectic sulfides were observed in the grain boundary. Especially, if the contents of Mn and S increased more in the miscibility gap area of the phase diagram, primary globular sulfides containing iron intrusions were observed. In case of Mn/S ratio of 70, if the contents of Mn and S was decreased in the Fe corner of the phase diagram, only bead-like sulfides were observed in the grain boundary. Despite the composition was outside the miscibility gap area of the phase diagram, if the contents of Mn and S increased, clusters of fine sulfide particles as well as fine spherical primary monophase sulfides were observed in the grain boundary.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.18 no.1
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• pp.132-149
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• 1992

This study relates to a microemulsion gel which is applied in various cosmetic preparations because of good appearance, superior stability and a thin, uniform, non-greasy fi Am on the skin. Main object of this study is to elucidate the influence of polyol(clarifying agent and/or coupling agent in microemulsion) on microemulsion and to establish the optimum conditions for microemulsion gel formation in the view of superior consistency, stability, clarity and pick-up from a container. The constituents of the system are composed of water, polar ester oi1, nonionic surfactant and polyol. Using the three-component phase diagram and the tetrahedral-phase diagram, we have investigated the changes of transparence regions, consistency and resonance effect by an impact in microemulsion gel varying in polyol ratio. The results of this study showed that the variation in the content of water and couple ins agent has major influence on the microemulsion gel and the optimum formation region of microemulsion gel is the widest when the ratio of glycerine(coupling agent) to water is 63-75% It is believed that optimum use of polyol seems to be helpful to obtain the microemulsion gel containing maximum amount of oil phase with minimum amount of surfactant which is recently one of the major problems of cosmetic chemists.

• Computers and Concrete
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• v.8 no.6
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• pp.735-755
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• 2011

The capability of a multi-directional fixed smeared crack constitutive model to simulate the flexural/punching failure modes of fiber reinforced concrete (FRC) laminar structures is discussed. The constitutive model is implemented in a computer program based on the finite element method, where the FRC laminar structures were simulated according to the Reissner-Mindlin shell theory. The shell is discretized into layers for the simulation of the membrane, bending and out-of-plane shear nonlinear behavior. A stress-strain softening diagram is proposed to reproduce, after crack initiation, the evolution of the normal crack component. The in-plane shear crack component is obtained using the concept of shear retention factor, defined by a crack-strain dependent law. To capture the punching failure mode, a softening diagram is proposed to simulate the decrease of the out-of-plane shear stress components with the increase of the corresponding shear strain components, after crack initiation. With this relatively simple approach, accurate predictions of the behavior of FRC structures failing in bending and in shear can be obtained. To assess the predictive performance of the model, a punching experimental test of a module of a façade panel fabricated with steel fiber reinforced self-compacting concrete is numerically simulated. The influence of some parameters defining the softening diagrams is discussed.

• The Journal of Fisheries Business Administration
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• v.39 no.1
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• pp.17-42
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• 2008

This study tried to build a structure model for the Korean flatfish aquaculture market by a system dynamics approach. A pool of several factors to influence the market structure was built. In addition, several reasonable factors related to the flatfish aquaculture market were selected to construct the causal loop diagram (CLD). Then the related stock/flow diagrams of the causal loop diagrams were constructed. This study had been forecasting a production price and supply, demand, and consumption volume for the flatfish market by a monthly basis, and then made some validation to the forecasting. Finally, four governmental policies such as import, storage, reduction of input, and demand control were tentatively evaluated by the created model. As a result, the facts that the demand control policy is most effective, and import and storage policies are moderately effective were found.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.107-114
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• 2003

Although cross rolling process has many advantages in forging a joint shaft, an automotive component of front axle unit, subsequent process is necessary to straighten its bending during forging process. In this paper the bending minimization of the joint shaft was studied to eliminate such an additional process. First of all, a characteristic diagram was used to find out factors affecting the bending of the shaft. Also design of experiments was utilized for estimating the influence of those factors. It was found that the phase angle, which is the difference in starting positions between upper and lower dies, was important to minimize the bending of joint shaft and die cooling is necessary to diminish the distribution of bending.

• The Journal of Korean Medical History
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• v.30 no.2
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• pp.101-118
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• 2017

Purpose : This paper explores the extent to which ZangFu diagrams made after Northern Song Dynasty were influenced by ZangFu diagrams made before Northern Song Dynasty, and how diagrams of the whole body and heart originated from MingTangZangFuTu and affected each other when quoted in books published after Northern Song Dynasty. Method : The author used four form factors including heart shape, internal curved lines, cylinder-like structures above heart, and wuzangxi (五臟系) which resembles a lotus flower which has not yet bloomed, to analyze and compare different ZangFu diagrams before and after the Northern Song Dynasty. Results : Two form factors, the shape of heart and wuzangxi, are described in ZangFu diagrams before Northern Song, and may have influenced ZangFu diagrams after Northern Song. However, the other two form factors (internal curved lines and cylinder-like structures above the heart) did not influence ZangFu diagrams after Northern Song. All form factors of heart found in WuCangLiuFuZhiTu (within the whole body) and diagram of heart in ZhenJiuJuYing (鍼灸聚英) were most similar, but the two paintings became less similar as they were cited in several books. With the exception of the form factor with structures above heart, the three other form factors are almost identical between two paintings produced after Northern Song dynasty, as displayed in the same book. Conclusion : ZangFu diagrams of the heart produced after Northern Song Dynasty, were not completely based on ZangFu diagrams made before Northern Song Dynasty. Diagrams of whole body and those of the heart were changed, while influencing each other after Northern Song.

• Korean Journal of Construction Engineering and Management
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• v.5 no.3 s.19
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• pp.97-105
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• 2004

Planning phase became very important because the construction market in Korea is often unpredictable. The existing feasibility analysis cannot fulfill its purpose in development projects because they are based on intuitive approach rather than systematic approach. The purpose of this study is to make a prototype of feasibility model to be a good investment. To build the model, first, risk factors which can be occurred in project had to be selected. Risk factors were divided into several groups in basis of characteristical risk. Economical risk factors were input on financial analysis. Then, to catch the relevance and influence of all risk factors, influence diagram and decision tree were made. Finally, sensitivity analysis was activated, then what the critical factors were, and how those factors could be solved. Through these procedures, the feasibility model that was made in this study could include both quantitative and qualitative factors. This model is expected to be used as a guide of feasibility analysis including all risk factors and is to serve systematic frame in planning and feasibility stage.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1993.10a
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• pp.24-30
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• 1993

When modeling a complex system we use an event tree to analyze propagation of failure. An event tree cannot represent the statistical interrelationships among parameters, but it can be represented as a statistically identical influence diagram so that parameter updating can be easily performed. After updating parameters we can calculate posterior distribution of the failure rate for each path. But exact distribution requires considerably complex numerical integration. We propose an approximation method to calculate the posterior and derive the predictive distribution of the time to next failure. Finally we introduce the system which implements our methodology.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.11a
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• pp.460-465
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• 2000

원자력 발전소의 중대사고는 비록 발생 확률은 매우 낮지만 사고 발생시 결말 효과가 크기 때문에 TMI 사고나 체르노빌 사고 이후 이에 대한 연구는 활발하게 진행되고 있다. 방사성 물질이 일단 환경으로 방출된 이후에 인체 및 환경에 영향을 미치는 주요 변수로는 풍향, 풍속, 강수량, 대기안정도로 대표되는 기상 조건과 방사선원 및 방출 고도, 열 함량, 방출 시간 등과 같은 방사선원 방출 특성에 관한 여러 가지 많은 변수들을 고려하여야 한다.(중략)

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.06a
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• pp.11-23
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• 1994

Formability of sheet metals can be evaluated using tensile testing. Easily measured tensile properties such as yield strength, tensile strength, elongation, strain hardening exponent, strain rate sensitivity and plastic strain ratio are important parameters to evaluated the sheet formability. This paper briefly explains how these properties are related to deep drawability and stretchability. The plastic anisotropy of sheet metals is usually attributed to the crystallographic texture. However dislocation distribution may influence the anisotropy.