• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.42-42
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• 2000

선형 터빈 익렬에 유입되는 자유흐름 난류 강도의 변화에 따른, 터빈 블레이드에서의 대류 열전달 현상에 대한 연구를 수행하였다. 익렬은 5개의 볼레이드를 선형으로 배치하여 구성하였으며, 현의 길이에 근거한 레이놀즈 수는 2.5${\times}$$10^5$, 3.5${\times}$$10^5$ 이다. 자유 흐름의 난류 강도는 익렬의 도입부에 설치된 격자의 형상에 따라 1.3%, 3.7%, 7.0%, 7.8%의 값을 나타내었다. 자유흐름의 난류강도는 정온 열선유속계로 측정하였으며, 블레이드 표면 온도 분포는 열전대를 사용하여 측정하고, 금속박판을 사용하여 균일한 열유속을 공급하였다.(중략)

• Journal of the Economic Geographical Society of Korea
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• v.17 no.1
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• pp.86-97
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• 2014

Incheon Free Economic Zone is the first free economic zone specified in 2003 in Korea. Previous research on the Free Economic Zone has focused on the activation of the free economic zone or foreign investment issue at the level of the national economic plan. Related to the development of a free economic zone, studies are currently insufficient on the relevance of the local economy, the development of linkages with hinterland, and the balanced regional development. Therefore, this study tried to investigate the impact of Incheon Free Economic Zone to the local economy through analyzing the causes and characteristics of the imbalance between the regions in Incheon by comparing before (1996~2002) and after (2003~2009) of the Incheon Free Economic Zone legislation (2003). The result shows that development of the free economic zone has not been connected to the local economy activation and the ripple effect on the old town in Incheon. Further, the construction of a large apartment and infrastructure in the free economic zones have increased the disparity between the free zones and the old town.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.220-228
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• 2008

In this study the aerodynamic characteristics of a canard-controlled missile with freely spinning tailfins were investigated by using a semi-empirical method and a CFD code. The mean aerodynamic coefficients for the rolling and roll damping moments were first calculated and then used to predict the roll-rate of freely spinning tailfins. The calculation of roll-rate in the CFD code was carried out by combining a Chimera overset grid system and 6-DOF analysis module. The predicted roll-rate was in good agreement with the experimental data for the roll and yaw canard control inputs. It was also shown that the results are in good agreement with the prediction by a CFD code. This indicates that the semi-empirical method can be used to predict the roll-rate of a canard-controlled missile with freely spinning tailfins.

• Journal of Korea Game Society
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• v.17 no.3
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• pp.107-116
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• 2017

Sandbox game users can double their satisfaction by re-creating a variety of play patterns. This creative process is due to the expansion of play through 'customizing' and 'action autonomy'. The purpose of this study is to investigate the structural limitations of freedom of online game. In a standalone game, the scalability due to the degree of freedom gives the user a strong motivation for world persistence. On the other hand, in online sandbox games such as MMORPG, it is confirmed that the goal-oriented tendency to gain advantage is the inherent limit of the freedom and expandability of the sandbox game. In this study, it is suggested that the cause and limit of growth of online-based sandbox game can be offset by the optimal solution factor.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.3
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• pp.1-9
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• 2011

The purpose of this study is to examine the dynamic characteristics of low, medium and high speed Maglev trains and guideways through dynamic interaction analysis. The coupled dynamic equations of motion for a vehicle of 10-dof and the associated guideway girders are developed by superposing vibration modes of the girder itself. The controller used in the UTM-01 Maglev vehicle is adopted to control the air gap between the bogie and guideway in this study. The effect of roughness, the guideway deflection-ratio and vehicle speed on the dynamic response of the maglev vehicle and guideway are then investigated using the 4th Runge-Kutta method. From the numerical simulation, it is found that the air gap increases with an increase of vehicle speed and the roughness condition. In particular, the dynamic magnification factor of the guideway girder is small at low and medium speeds, but the factor is noticeable at super-high speeds.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.43-66
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• 2009

The purpose of this paper is to analyze the free economic zone policy from the viewpoint of Policy Science. because of insufficiency on policy science of the previous researches for the free economic zone. So Trying on free economic zone policy from the viewpoint of policy science, the paper is shown the new proposal for free economic zone policy. For this trying, this paper used to the viewpoint of policy science; (1) the system of policy(policy process, policy content(pattern)), (2) the policy implementation(local government-central intergovernmental management). In the end, beyond the previous research on the free economic zone policy, shown on not only new viewpoints on the free economic zone, but also, the solutions of practical implementation for free economic zone on the free economic zone.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.3
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• pp.175-182
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• 2022

In many engineering problems, the dynamic substructuring can be useful to analyze complex structures which made with many substructures, such as aircrafts and automotive vehicles. It was originally intended as a method to simplify the engineering problem. The powerful advantage to this is that computational efficiency dramatically increases with eliminating unnecessary degrees-of-freedom of the system and the system targets are concurrently satisfied. Craig-Bampton method has been widely used for the linear system reduction. Recently, multi-level optimization (such as target cascading), which propagates the system-level targets to the subsystem-level targets, has been widely utilized. To this concept, the genetic algorithm which one of the global optimization technique has been utilized to the substructure optimization. The number of internal modes for each substructure can be obtained by the genetic algorithm. Simultaneously, the reduced system meets the top-level targets. In this paper, various numerical examples are tested to verify this concept.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.3
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• pp.116-121
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• 2005

In the present paper, a new calculation algorithm far solving large scale environmental or geophysical flows with free surface is proposed where the non-hydrostatic pressure component is taken into consideration. Predictor-corrector fractional step approach with explicit, forward time marching scheme in the sigma coordinate system is employed. In order to validate the present calculation algorithm and to estimate the effects of non-hydrostatic pressure on resultant flow and free surface movements, example calculations are carried out for typical steady and unsteady flow problems. Present method can be applied to the meso-scale free surface flows with complex bottom topography where MAC-like 3-d hydrodynamic calculations are quite ineffective and uneconomic.

• Journal of Korean Library and Information Science Society
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• v.47 no.4
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• pp.93-122
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• 2016

The present study investigates librarians perceptions of Free Learning Semester, and their commitment to program development for coordination with Free Learning Semester, and whether they currently offer programs for Free Learning Semester. The study results are as follows. First, the results on perceptions of Free Learning semester showed that 54.20% of the librarians who participated in the study were aware of Free Learning Semester, and 80.15% had participated in training related to Free Learning Semester. Regarding the anticipated outcomes of implementation of Free Learning Semester, "Participation in various experiential activities offered through Free Learning Semester" was the most common response, and regarding special considerations in Free Learning Semester, "Need for instituting the dedicated workforce and enhancing their sense of responsibility and expertise" was the most common response. Second, regarding the library program development and provision for coordination with Free Learning Semester, 58.02% thought that the implementation of Free Learning Semester was an opportunity to expand the role of libraries, while insufficient budget was listed as a barrier. In addition, 63.36% stated that they had no experience in providing a program in a library. Finally, the results on the perception on the Free Learning Semester program they want to provide in a library showed that "Human Library" and "Read! Think! Dream!" were the programs they want to provide most, with the mean score of 3.939.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.42 no.1
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• pp.1-11
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• 2005

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of agile prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. However, there is an important problem with the conventional 2D lamination method. That is the inaccuracy of 3D model surface, which is caused by the stair-type surface generated in virtue of vertical 2D cutting. In this paper, We design the new control algorithm that guarantees the constant speed, precise positioning and tangential cutting on the 5DOF SFFS. We develop the tangential cutting algorithm to be controlled with constant speed and successfully implemented in the 5DOF CAFL/sup VM/ system developed in this paper. Finally, this paper confirms its high-performance through the experimental results from the application into CAFL/sup VM/ system.