• 한국전산유체공학회지
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• 제14권2호
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• pp.39-45
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• 2009

In engine room, proper enclosure system is preferable for reducing noise level but the enclosure system in the engine room causes bad influence on cooling performance due to poor ventilation. Cooling efficiency of the enclosure system can be improved by varying fan speed and proper flow path for ventilation. In this study, numerical analysis is performed to assess cooling effect of the enclosure system using finite volume method. The RNG k-$\varepsilon$ model is adopted for turbulence model along with heat exchanger model and porous media model for heat exchanger analysis, and moving reference frame model for rotational fan. Verification result shows reasonable agreement with experimental data. Analysis results show direct effect of velocity and temperature distribution on cooling ability in the enclosure system. Enclosure system of case B shows high heat transfer coefficient and has the smallest area ratio of opened flow passages which is good for noise level reduction.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.135-139
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• 2002

By means of correlation analysis and path coefficient analysis, 18 characteristics of 325 conserved silkworm races were studied for the selecting efficiency on main silk quality characteristics. The result showed that selecting lines with heavier cocoon weight are beneficial to raise the weight of have. Choosing strains with higher cocoon shell percentage, longer filament length and better reelability percentage is good for increasing non-broken filament length. Selecting lines with medium daily weight of have produced in the fifth instar, medium cocoon shell percentage and simultaneously selecting heavier cocoon shell weight are favorable to promote reelability percentage. Choosing strains with heavier cocoon weight, higher cocoon shell percentage, heavier daily weight of bave produced in the fifth instar and heavier weight of bave but shorter filament length may hopefully breed out a race with thick filament size. And selecting strains with heavier weight of have and fine filament size are beneficial to increase filament length. Selecting lines with higher cocoon shell percentage and heavier weight of bave are favorable to raise raw silk percentage of cocoon. There are no significant direct or indirect correlation coefficient between viability and major characteristics of silk quality. It is, therefore, feasible to breed a silkworm race with excellent vitality and good silk quality as well.

• 한국작물학회지
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• 제27권1호
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• pp.87-93
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• 1982

담배 황색종 품종인 SC72와 Hicks를 교배하여 그 $F_1$잡종식물의 약으로부터 유기한 반수체식물을 배가시켜 얻은 30계통의 10개 양적형질에 대한 변이, 유전력, 유전상관 및 경로계수의 분석에 의하여 각형질들의 유전현상을 본바 그 결과를 요약하면 다음과 같다. 1. 교배친간 각 형질의 변이폭은 1.5~37.8%인데 비하여 반수체배가계통간에는 19.6%~100.1%로 현저히 크게 나타났고 평균치에 있어서는 교배친에 비하여 반수체배가계통들은 nicotine, 수확엽수 및 엽장폭비가 증가하는 경향이나 그외 특성들은 저하되는 경향이었다. 2. 유전력은 개화일수 및 수확엽수는 높게, reducing sugar, kg당 가격 및 수량은 낮게, 그외 형질들은 중간치를 나타내었다. 3. 유전상관의 값은 표현형상관보다 그 값이 다소 높은 경향이었고, 수량은 kg당 가격, 엽폭, 수확엽수 및 reducing sugar와는 정의 상관이었고, nicotine은 엽장폭비를 제외한 타형질과는 부의 상관을 나타내었다. 4. 수량과 각형질간의 경로계수를 분석한 결과 수확엽수와 엽폭이 수량에 미치는 직접효과가 컸으며, 간접효과는 개화일수와 초장이 크게 나타났다.

• 대한가정학회지
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• 제30권1호
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• pp.163-178
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• 1992

The purpose of this study was to test system model for family resources management developed by Deacon and Firebaugh. The data were collected by means of a questionnaire destributed to a stratified sample of 600 housewives living in Seoul. The questionnaires specially developed by the researchers contained of 118 items. the coefficient alpha reliability estimate for this instrument was conducted using Cronbach' procedures. The data were analyzed using frequency, percentile, mean, step wise multiple regression and path analysis. The results of path analysis showed that the level of the elements of satisfaction with the management was correlated with demands(the household size, the age of the last child, employment status of respondents), resources(marital satisfaction, health of respondents), and throughput(standard setting, reality in planning, the existence of facilitating conditions). A system model for family resource management received considerabel empirical support. This presumed that the components of demands lead to the lower satisfaction with management. The throughput components were also important in explaining satisfaction with management some of research and methodology issues for the advanced study were suggested.

• 소성∙가공
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• 제32권1호
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• pp.35-40
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• 2023

In the case of a wire with a very fine diameter during the multi-stage drawing process, the heterogeneity of the deformation in the radial direction tends to develop strongly as the amount of deformation is accumulated. It is known that the heterogeneity of deformation in the radial direction of the wire is closely related to the process parameters during the multi-stage drawing process. In this study, finite element analysis (FEA) was used to theoretically examine the effect of friction between the surface of the wire and the drawing die during the multi-stage drawing process of Cu-0.2wt%Mg alloy on the deformation heterogeneity developed in the radial direction of the wire. The distribution of effective strain, radial strain, circumferential strain, and shear strain developed in the radial direction of the wire during the multi-stage drawing process was analyzed while changing the friction coefficient, and the results were analyzed and compared for each path and position. The FEA results revealed that the shear strain developed in the radial direction of the wire during the multi-stage drawing process of Cu-0.2wt%Mg alloy showed the most non-uniform distribution and was also severely affected by the friction coefficient.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.317-328
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• 2018

본 연구에서는 창극공연의 서비스 품질이 공연경험속성 및 관객만족에 미치는 영향을 검증하고, 이 과정에서 서비스 가치 및 전통이미지의 매개효과를 검증하였다. 본 연구의 대상은 서울 지역에서 10월 중 공연된 창극공연을 유료관람한 성인 남녀 211명으로서, 수집된 자료를 이용하여 공분산구조분석을 통해 얻은 경로계수로 모형과 가설 검정을 실시하였다. 검증결과, 관객이 지각하는 창극공연 서비스품질의 공연프로그램 품질, 물리적환경 품질, 상호작용 품질은 공연경험속성에 각각 통계학적으로 유의하게 정(+)의 관계를 보였다. 공연경험속성과 서비스가치, 공연경험속성과 전통이미지 간의 경로계수도 각각 통계학적으로 유의하게 정(+)의 관계를 보였다. 그리고 공연경험속성과 관객만족 간의 경로계수는 정(+)의 관계를 보였고, 서비스가치와 전통이미지, 서비스가치와 관객만족, 전통이미지와 관객만족 간의 경로계수도 각각 통계학적으로 유의하게 정(+)의 관계를 보였다. 결국 본 연구의 모든 가설은 채택되었으며, 본 연구의 결과는 창극공연의 대중화와 현대화, 공연예술산업 차원의 마케팅전략에 있어서, 그 공연 서비스 품질과 경험속성을 반영하여, 관객의 만족에 미치는 영향을 확인하고, 이 과정에서 서비스 가치와 전통이미지의 역할 및 작용을 검증하였다는데 의의가 있다.

• 무역학회지
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• 제47권6호
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• pp.135-171
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• 2022

This study is to find out how psychological characteristics and management capabilities of small manufacturers influence business performance through parameters including self-efficiency, network, and collaboration strategies. The survey was implemented between December 26, 2017 and January 15, 2018. The final 439 valid questionnaires were collected and used for analysis. The results were followed. First, the relationship between psychological characteristics and self-efficiency, and the path coefficient for psychological characteristics and network were significant. Second, management capabilities was related to self-efficiency, and the path factor for managing capability and network relationships was significant. Lastly, the path coefficients for self-efficiency and collaboration strategies were not significant, and the path coefficients for network and collaboration strategies were significant.

• Tribology and Lubricants
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• 제30권1호
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• pp.15-20
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• 2014

A more accurate expression for effective viscosity is obtained using a linear regression of the data from Fukui-Kaneko's model, which are obtained through numerical calculations based on the linearized Boltzmann equation. Veijola and Turowski's expression is adopted as a base function for effective viscosity. The four coefficients in that equation are optimized, and sensitivity analysis is conducted for these coefficients. The results show that the coefficient for the first-order Knudsen number is the most accurate, whereas the coefficient in the exponential of the Knudsen number is the least accurate compared with Fukui-Kaneko's results. The expression for effective viscosity is accurate within 0.02% rms of Fukui-Kaneko's results for the inverse Knudsen numbers from 0.01 to 100 and surface accommodation coefficients ranging from 0.7 to 1.

• 한국해양공학회지
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• 제30권5호
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• pp.381-388
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• 2016

An underwater glider makes it easy to explore a wide area with low power. However, an underwater glider is difficult to use for rapid collection, because the surfacing location cannot be predicted after a dive. Thus, simulation research is needed to predict the swimming path. In this paper, based on research, a linearized equation is derived for the drag coefficient at each angle of attack by assuming the boundary conditions for the Slocum underwater glider and performing a computational flow analysis.

• 지식경영연구
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• 제10권2호
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• pp.35-48
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• 2009

The paper proposes a quantitative causal ordering map (QCOM) to combine qualitative and quantitative methods in a framework. The procedures for developing QCOM consist of three phases. The first phase is to collect partially known causal dependencies from experts and to convert them into relations and causal nodes of a model graph. The second phase is to find the global causal structure by tracing causality among relation and causal nodes and to represent it in causal ordering graph with signed coefficient. Causal ordering graph is converted into QCOM by assigning regression coefficient estimated from path analysis in the third phase. Experiments with the prediction model of Korea stock price show results as following; First, the QCOM can support the design of qualitative and quantitative model by finding the global causal structure from partially known causal dependencies. Second, the QCOM can be used as an integration tool of qualitative and quantitative model to offerhigher explanatory capability and quantitative measurability. The QCOM with static and dynamic analysis is applied to investigate the changes in factors involved in the model at present as well discrete times in the future.