• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.537-542
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• 2012

Rolling stocks are often subjected to the effects of natural strong wind or wind pressure caused by the crossing train. These wind pressure cause the falling-off in running stability and overturn safety. It is sometimes reported that trains are blown over by a gust of wind. So, many countries enact regulations to secure the overturn safety for wind speed. In this study, theoretical equations of overturn safety based on multi-body model are derived and analyzed the difference between the result of the solid model and that of multi-body model. In case of multi-body model, it is assumed that the degrees of freedom for carbody and bogie are assigned an independent values respectively. The results show that the latter approach based on multi-body model can access the overturn safety of train and replace the conventional method by using commercial software which is accessing with decrement of wheel load.

• 한국해양학회지
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• v.30 no.4
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• pp.365-370
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• 1995

A new piston-type Free-fall corer (FFC) was developed for the sampling of core sediments in aquatic environments. The corer, named "KORDI-FFC", is the modified sampler of the existing FFX with an open barrel gravity corer. It was rested successfully on the muddy bottom in the Chinhae Bay and on the sandy bottom (Mz=3$\phi$) in nearshore areas around the Cheju Island. Several merits found in the unstrument are; $\circled1$ operation on a small vessel without winch and cable, $\circled2$ low cost of construction, $\circled3$ little disturbance of surface sediments during the sampling, $\circled4$ short round-trip time of sampling, and $\circled5$ simultaneous performance of other research works during the lowering of FFC.

• Journal of the Korean Society for Library and Information Science
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• v.53 no.2
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• pp.29-48
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• 2019

The free learning semester system focuses on the activation of career education of middle school students as an educational policy that links career recognition in elementary school, career search in middle school, and career planning in high school. This system was fully implemented in 2016 and public libraries also provided various programs. This study analyzed the free learning semester system programs of public libraries in Busan city and demonstrated the contribution of local development. As a result, career and job search, career exploration and experience, and information literacy enhancement programs contributed to local knowledge culture, reading culture, learning culture, living culture and leisure culture. However, contribution of reading exhibitions, job experience, information literacy enhancement to the leisure culture and local economy were limited. Therefore, it is desirable that all libraries should add programs related to knowledge ecosystem structure, digital information gap, human healing, social environment issues, future job prospects, and provide information literacy programs.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1718-1723
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• 2003

This paper presents a computational method for deformation modes of a flexible body in multibody system from the experimental modal analysis and an efficient method for flexible multibody dynamic analysis by use of the modes. It is difficult to directly use experimental modal parameters in flexible multibody dynamic analysis. The major reasons are that there are many inconsistencies between experimental and analytical modal data and experimental noises are inherent in the experimental data. So two methods, such as, a method for ortho-normalization of experimental modes and the other one for mode expansion, are suggested to gain deformation modes of a flexible body from the experimental modal parameters. Using the virtual work principle, the equation of motion of a flexible body is derived. The effectiveness of the proposed method will be verified in the numerical example of cab vibration of a truck by comparing analysis and test results.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.2
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• pp.125-132
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• 2000

To take an information of substitutent effect and thermodynamic of association at thiacarbocyanines, association constant $K_{D}$, free energy of association $\Delta$ $G_{D}$, enthalpies of association $\Delta$ $H_{D}$ were measured by spectrophotometer according to dependence on concentration of dyes and temperature of aqueous MeOH system. With increase of concentration dyes or decrease of temperature of aqueous MeOH system, absorption spectra of dyes exhibited equlilibria shift toward the dimer. Phenyl meso substituted thiacarbicyanine, DyeIII, resulted in higher $K_{D}$ and $\Delta$ $G_{D}$ values than DyeI and DyeII. To easily make an association of thacarbicyanine, meso substutituent group need to be a flat structure, which will make a park as well as lain tiles.tiles.ructure, which will make a park as well as lain tiles.les.

• The Korean Journal of Zoology
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• v.36 no.2
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• pp.293-303
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• 1993

쇠오징어(Sepiella maindroni)흠반의 외측 상피조직에서 3종류의 감각세포(A, B 및 D형 감각세포)와, 1종류의 감각상피세포(C형 감각 상피세포) 그리고 2종류의 점액세포(a 및 b형 점액세포)가 각각 관찰되었다. A 및 B형 감각세포는 분포상태가 다를 뿐 형태는 거의 유사한 세포이고 많은 분비액포를 지닌 해면질 형태의 세포로서 전자 밀도가 낮은 물질을 분비하는 분비성 감각세포로 확인되었다. 0형 세포는 매우 작은 감각세포로서 세포의 자유면에 긴 융모가 밀생되어있었고, 측면원형질막은 불규칙한 수지상 연접을 이루고 있었다. 이 세포는 전자밀도가 매우 높아서 검게 보였다. C형 감각 상피세포도 세포의 자유면에 긴 미세융모가 밀생되어있는 단층 원주상 세포로서. 이 세포 역시 측면원형질막이 불규칙한 수지상 연접을 이루고 있고. 엽접내에는 많은 소포와 약간의 사립제가 관찰되었다. 3형 점액세포는 세포질속에 내강이 팽창된 활면소포체를 소지하고 있으며 전자밀도가 높은 구형의 점액과립을 형성하였고, b형 점액세포도 전자밀도가 중등도인 점액질 과립을 소지하고 있었다.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.21-28
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• 2006

Vibration of a non-linear system with multiple degrees of freedom under random parametric excitations was evaluated by probabilistic method. The non-linear characteristic terms of system structure were quasi-linearized and excitation terms were remained as they were. An analytical method where the expectation values of square mean of error was minimized was used. The numerical results were compared with those obtained by Monte Carlo simulation. A linear congruential generator and Box-Muller method were used in Monte Carlo simulation. The comparison showed the results by probabilistic method agreed well with those by Monte Carlo simulation.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.1-6
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• 2011

The free-wing tilt-body aircraft is researched in the flight performance characteristics such as short take-off and landing capability, and reduced sensitivity to gust and center of gravity (CG) change. Due to the main wing separating from the fuselage, the high tiltable empennage, and the stub-wing strongly influencing from the propeller wake, the resulting vehicle aerodynamics and flight dynamics are quite different from those of a conventional fixed-wing aircraft. Using the governing flight dynamics model was studied previously, all of speed and body tilt angle is simulated to determine the flight envelope by a non-linear 3-DOF flight simulation analysis. Though flight performance and trimmability are studied, the flight model of free-wing tilt-body aircraft is to reduce the hidden risk and to achieve the successful flight test. It is analyzed the flight characteristics that distinguishes free-wing tilt-body aircraft from the conventional aircraft.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.4
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• pp.1-5
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• 2011

The free-wing tilt-body aircraft is researched in the flight performance characteristics for center of gravity (CG) change. All of speed, body tilt angle and center of gravity change are simulated to determine the flight envelope by a non-linear 3-DOF mathematical model. In flight, this aircraft configuration changes by the tiltable empennage. Then, flight dynamics distinguishes from those of a conventional fixed-wing aircraft. Though flight performance and trimmability are studied by CG change, the flight model of free-wing tilt-body aircraft is to reduce the hidden risk and to achieve the successful flight test. It is analyzed the flight characteristics by CG change that distinguishes free-wing tilt-body aircraft from the conventional aircraft.

• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.114-122
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• 2007

Recently, Game Rating Board has been established. It is to follow worldwide trend in building up publicity, autonomy and professionalism under the framework to assure freedom of expression. This article analyzed major nation's game rating system, and showed some points to need improvement which are to have more detailed classification in game rating, to modify contents descriptor, to appoint committee members with expertise on game, to revise articles to be capable of misuse, and to become a nongovernmental organization.