• Journal of the Korean Society of Safety
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• v.21 no.2 s.74
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• pp.46-51
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• 2006

The smoke exhaust system is one of the effective systems to save lives when fire occurs underground. This study presents a complete analysis of effective smoke exhaust and smoke characteristics for a fire occurring with a transverse ventilation system use as a smoke exhaust system. The performance of the smoke management system was studied by computer modeling using FDS version 3.1. A fire size of 20MW was used for tunnel with balanced exhaust transverse ventilation. The smoke management design and the procedure as simulated in this study are also compliant to the tunnel construction and fire codes of Korea.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.234-238
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• 2015

When we use a Finite Elements Method (FEM) to solve a linear static analysis problem, number of elements need to be sufficiently small for convergence of the solution. If we analysis a part, whose curvature is varying heavily, we face to determine how small the elements size is, because the calculated stress is increased as the elements are smaller. In this case, we need to analysis with mesh insensitive method, stress linearization. We can get a solution that is not varying with the elements size if the size is smaller than a certain level. In this paper, we evaluate a pressure vessel having geometrical discontinuities using stress linearization. First, we analysis the vessel with global model, including all part of the vessel, using large shell elements. Second, we analysis the local part of the vessel, which is the small part occurring maximum stress, using small continuum elements. Last, we evaluate the safety of the pressure vessel according to the ASME Sec. VIII Div 2.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.2
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• pp.61-70
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• 2008

This paper describes case studies on workflow impact analyze with an enterprise ontology (EO). We build the EO with an ontology editor $Prot{\acute{e}}g{\acute{e}}$ and integrate concepts of enterprise architecture and a process model into it to expand the EO. We use the expanded EO and Prolog query rules to analysis workflow dependency relations from the perspectives of routing, data and role. Through this, we analyze impact of changes in workflow process. Moreover, we have found the effectiveness of the EO and $Prot{\acute{e}}g{\acute{e}}$ in modeling business management and, in particular, workflow representation and management.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.2
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• pp.52-60
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• 2011

Korea is the best country for ship-building. But nowadays, the speedboat and yacht are not mostly developed yet. For the sleek lines of ship, more innovative transmission system should be obtained in the ship industry. In general, marine transmissions often use the straight shafts and the helical gears. So it makes problem that engine-room requires large space. In this case, conical gear is the best solution for this. Until now, technology of conical gear is not generalized, but it will be increased more through many applications. So, in order to get conical gear design technology by ourselves, this thesis is conducted. This paper was written to gain useful information of marine gearbox design applied conical gear through the measurement of backlash, computer analysis and tooth contact test of helical conical involute gear pairs.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.319-321
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• 2003

RUP의 Unified Process Model에는 Use Case Model, Analysis Model, Design Model, Deployment Model, Implementation model, Test Model의 6가지 모델이 있다. 이 모델들은 모두 일관성이 있다. 한 모델에서 나오는 요소들은 전, 후 단계에서 다른 모델들과 Trace Dependencies를 갖는다. 이러한 의존적인 관계들은 각각의 요소들 사이의 진행, 기록 관계를 나타낸다. 그러나 대부분의 데이터 모델 설계는 이러한 관계와 의존 없이 설계되어져 전체적인 일관성을 이루지 못 하였다. 본 논문에서는 이러한 관계를 유지 하면서 사용자의 요구사항에 일관성 있는 데이터 모델을 설계하고자 한다. 따라서 본 논문에서는 대학 종합정보시스템 구축의 일부분인 자산관리 시스템을 분석하여 데이터 모델을 제시한다.

• Journal of KIBIM
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• v.9 no.3
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• pp.54-60
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• 2019

After Landscape Act was enacted, as awareness of landscape has increased and the need of expanding targets of landscape design review and improving landscape examination in terms of quality, this study aims to describe a technique of creating three dimensional landscape simulation model which is used for landscape design review. For this, the author of this study conducted analysis in terms of function and use of programs and compatibility with programs to find a way of creating models with the most efficient and optimum process. For creation of landscape simulation models, initial creation is important but in case that changes occur by operator changing or discussing development plans, rapid correction and change are needed. Therefore, this study described how to build more accrurate and efficient simulation at initial review and how to create a landscape simulation model for rapid response to changed plans during reconsideration.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.326-332
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• 2019

In the case of conventional soft robots, the basic stiffness is small due to the use of flexible materials. Therefore, there is a limitation that the load that can bear is limited. In order to overcome these limitations, a study on a variable stiffness method has been conducted. And it can be seen that the jamming mechanism is most effective in increasing the stiffness of the soft robot. However, the jamming mechanism as a method in which a large number of variable act together is not even theoretically analyzed, and there is no study on intrinsic principle. In this paper, a study was carried out to increase the stability of the force chain to increase the stiffness due to the jamming transition phenomenon. Particle size variables, backbone mechanisms were used to analyze the stability of the force chains. We choose a jamming mechanism as a variable stiffness method of a soft robot, and improve the effect of stiffness based on theoretical analysis, modeling FEM simulation, prototyping and experiment.

• Journal of Contemporary Eastern Asia
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• v.20 no.2
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• pp.1-18
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• 2021

This study investigates the influence of social network services (SNS) and political podcasts on youth participation in candlelight rallies leading up to the impeachment of the Korean president. It also examines the effect of SNS and podcasts on online participation through SNSs. It was found that engaging in political discussions with friends or parents and news media use, including TV and Internet newspapers, exerted a major positive influence on participation in the rallies. However, SNS had a negative influence, while podcasts did not have a significant effect. On the other hand, SNS and podcasts had a positive influence on online participation. The results of structural equation modeling showed that SNS and podcasts affected SNS participation in the mediation of political discussion and political efficacy.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.7
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• pp.197-203
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• 2022

The agricultural sector has an important contribution to the economic development of Vietnam in particular and other countries in general. The growth of enterprises in the industry is an important bridge in promoting the economic development of the country. Currently, the policies of the Government of Vietnam always create favorable conditions for enterprises to conduct business, especially enterprises in the agricultural sector. The study aims to assess factors influencing the profitability of listed firms in Vietnam's stock market. Using 40 enterprises in the agricultural industry listed on the Ho Chi Minh City Stock Exchange and the Hanoi Stock Exchange and using advanced econometric modeling, dealing with defects in the regression model, the research results show that large-scale firm has higher economic efficiency than small-scale firm. In addition, a firm with higher use of loan capital is associated with a more efficient firm, reflected in the relatively good debt management ability of enterprises in the agricultural sector. Adversely, growth and age do not have any impact on firm performance. Macroeconomic factors do not impact profitability. Finally, the study has some policy implications for developing agricultural businesses in the case of Vietnam.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.469-470
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• 2009

확장 관계는 유스케이스 수행 중 조건에 따라 기반 유스케이스의 기능을 확장하고자 할 때 활용된다. 그러나 현재 확장 관계가 조건에 따른 분기를 위해 활용하는 확장점은 레이블 형태를 가지며, 이는 객체지향 프로그램의 작성을 어렵게 만드는 요인이 된다. 또한 확장기능 수행 후 기반 유스케이스로의 복귀점에 대한 명확한 모델링 기준이 부족하여 확장 관계의 활용이 어려운 것이 현실이다. 본 논문에서는 유스케이스 확장 관계의 개선 모델링 기법을 제시한다. 개선 모델링은 확장 관계의 분기점으로 기존 레이블 형태의 확장점 대신 액티비티 노드를 설정한다. 또한 분기점과 쌍으로 복귀점에 해당하는 액티비티 노드를 명시적으로 지정 가능하다. 이를 통해 확장 관계의 분기 및 복귀의 보다 명확한 명세가 가능하다.