• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1091-1096
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• 2010

This study was conducted to provide reference data for designing an alarm system that can help prevent the overturning of a container crane under wind load. Two methods, namely, fluid-structure interaction (FSI) analysis and windtunnel test, were adopted in this investigation. To evaluate the effect of wind load on the stability of the crane, a 50-ton-class container crane that is widely used in container terminals was adopted as the analysis model and 19 values were considered as design parameters for wind direction. First, the wind-tunnel test for the reduced-scale container crane model was performed according to the wind direction by using an Eiffel type atmospheric boundary-layer wind tunnel. Next, the FSI analysis for the real-scale container crane was conducted using ANSYS and CFX. Then, the uplift force determined from the FSI analysis was compared with that determined from the wind-tunnel test. Finally, a formula to compensate for the difference between the results of the FSI analysis and the wind-tunnel test was proposed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.1
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• pp.26-33
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• 1992

Physical experiments were conducted to investigate the suspension properties of silty mud in combined wave-current flow. Suspension mass when there was opposing current was much higher than that when there was following current. It is due to the fact which strong turbulent flow in the bottom is developed in the opposing current but oscillatory flow effect decreases in the following current. Critical bed shear stress for suspension of silty mud in combined wave-current flow was deduced to be $\tau$$_{c}$～0.045 N/$m^2$. Formulas expressing the relation with initial suspension rate with bed shear stress, and the relation between the former and measured significant wave height were deduced. The relationship of initial suspension rate with bed shear stress was significantly scattered, but the relationship with measured significant wave height was reasonably good. When there is wave only, vertical diffusion coefficients of sediment were calculated from the vertical concentration gradients of suspended sediment when the concentration of suspended sediment approached to nearly equilibrium state. The diffusion coefficient increased exponentially with height from the bottom in the lower half of the flow depth but were nearly constant in the upper half of the flow depth.h.

• Journal of the Korean Institute of Gas
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• v.13 no.3
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• pp.33-42
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• 2009

A numerical analysis of reactive flow in a liftoff flame is accomplished to elucidate the characteristics of liftoff flame. To verify reliance of numerical calculation, the liftoff heights of liftoff flame for various fuel exit velocities are compared between the existing experimental research results and the present calculation results. The flame propagation velocity is conducted at the flow redirection point which is on a stoichiometric line ahead of flame front. This point was selected constant distance from triple point regardless of fuel exit velocity at the previous research. This causes considerable errors for the flame propagation velocity and scalar dissipation rate. The main issue of the present research is to establish the resonable method to select the redirection point and so that to clarify the relationship between flame propagation velocity and scalar dissipation rate, which is the core properties in a triple flame stability.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.641-648
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• 2009

The study presents sewage sludge flotation and thickening efficiencies which changes chemical conditioning and mixing conditions using a flotation thickening system with a microbubble generating pump. Flotation and thickening of sewage sludge are shown to significantly influence kinds of coagulants more than Gt values. It is found that the flotation and thickening efficiencies for kinds of coagulants follows the order: $Al_2(SO_4)_3$ < PSO-M < $Fe_2(SO_4)_3$. We shows that the flotation thickening system(1.6 $m^3$/d) could be continuously operated during two hours on operation conditions in the lab-scale experiments. Sludge thickening efficiency in the A/S ratio of 0.029 - 0.019 mL/mg was found to be very efficient, reaching to 300.0~335.7%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.229-236
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• 1995

This study is the 3-D positional analysis for track of magnetically levitated vehicles to precise construction and periodical safe diagnosis by photogrammetry. In the result, we could improve the accuracy of Z as well as X, Y using the modified control points of spatial distribution to the plane distribution of the absolutly effective control points to accuracy and diagnosis the the track of magnetically levitated vehicles using the below 1㎜ accuracy. And we could analysis the 3-D precise positions and efficiently decide the geometric characteristics of the cant and gradient to the instrument.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.143-155
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• 2021

The purpose of this study is to adopt qualitative research methods for alpine snowboard athlete to analyze their injury factors in depth from a psychological perspective. Therefore, in-depth interviews were conducted on four outstanding Alpine Snowboard athlete, and the results were as follows. Among the factors of the injury of Alpine snowboard athlete, the psychological point of view was derived from five factors: 'Trait Anxiety', 'Personality Characteristic', 'Expectancies of Significant Others, 'Discrepancy between ability and expectation' and 'Trauma Injuries'. The five psychological injury factors have expressed the raw data of the subject in a case-oriented manner, and empirical and field-oriented interview data will enable in-depth analysis of psychological factors related to injury to future Alpine snowboard athlete and coaches. It is expected to be used as a basis for injury prevention and countermeasures. All data can be used as a basis for positive effects on the quality of life of athletes and athletes in winter sports.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.491-494
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• 2018

체감형 스포츠 게임은 신체활동이 부족한 어린이들의 활동량을 늘릴 수 있는 해결 방안으로 부상하고 있다. 기존 체감형 스포츠 게임관련 연구는 성인을 대상으로 한 연구들이 대부분이며 어린이를 대상으로 한 연구는 미흡한 실정이다. 제안하는 어린이 체감형 스포츠 게임 요소는 기존 성인대상의 체감형 스포츠 게임 요소들과 어린이 디자인 요소들의 공통 요소를 도출하고, 어린이에 맞춰 재해석한다. 도출된 요소는 적용해야 할 어린이 체감형 스포츠 게임에 맞춰 실제 요소를 도출하고, 실제 요소들을 고려하여 게임을 제작한다. 어린이 체감형 스포츠 게임 요소는 어린이를 대상으로 한 체감형 스포츠 게임 제작 및 평가 시 가이드라인으로 활용될 수 있을 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.38-45
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• 2020

A magnetically levitating capsule train, which runs inside the sub-vacuum tube, can reach ultra-fast speeds by dramatically reducing the aerodynamic drag and friction. The capsule train uses the superconductor electrodynamic suspension (SC-EDS) method for levitation. The SC-EDS method has advantages, such as a large levitation gap and free of gap control, which could reduce the infra-construction cost. On the other hand, disadvantages, such as the large variation of the levitation-guidance gap and small damping characteristics in levitation-guidance force, could degrade the running stability and ride comfort of the capsule train. In this study, a dynamic analytical model of a capsule train based on the SC-EDS was developed to analyze the running dynamic characteristics. First, as important factors in the capsule train dynamics, the levitation and guidance stiffness in the SC-EDS system were derived, which depend non-linearly on the velocity and gap variation. A 3D dynamic analysis model for capsule trains was developed based on the derived stiffness. Through the developed model, the effects of the different running speeds on the ride comfort were analyzed. The effects of a disturbance from infrastructure, such as the curve radius, tube sag, and connection joint difference, on the running stability of the capsule train, were also analyzed.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.415-430
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• 2013

In the present study, injuries in Taekwondo athletes during training and competitions was investigated via questionnaire. The purpose of this research lies in encouraging Taekwondo instructors and trainees to take precautions against injuries furnishing a variety of data obtained by analyzing the causes of injuries by region with ones undergoing a training. Understanding how frequently trainees get injured by region. we will be able to promote safety. which is such a meaningful move to improve training condition. The subjects of this study were 413 playes at the gym focusing on South Chungcheong province. Questionnaires for taekwondo players had the results as follows. The research reveals that physical injuries among Taekwondo athletes are caused by various reasons, regardless of sex and grade, and that the injures are repeatedly occurring, Therefore, in order t prevent and minimize the occurrence f injuries among Taekwondo athletes, not only the athletes but also trainers, business administrators, and educators need to pay careful attentions and take necessary measures accordingly. Also, pre-education on precaution against injuries must be put into practice thoroughly and an environment in which the inured could receive swift first aid treatment as well as follow-up measures shall be formed. this, in the end, is expected to contribute in improving not only the health of the athletes but also their performances in matches.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.37-46
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• 2020

This study was aimed at investigating the activities of a badminton club and designing smart wear to prevent sports injuries during badminton club activities. Everyone is familiar with sports in an aging society and clubs are gradually developing. Popular badminton club activities lead to frequent sports injuries, especially ankle injuries, which are a serious problem that hampers members' participation in sports. Therefore, this study aims to propose a prototype design for smart wear to prevent sports injuries, including ankle injuries. First, we identified the characteristics and considerations of members of badminton clubs, and the components of smart wear to prevent sports injuries. Second, members of the badminton clubs and an elite badminton player participated in a survey on the issues and requirements associated with wearing smart wear. Third, usage scenarios for smart wear were created based on literature reviews and the user assessment lists. Fourth, a prototype of the smart wear to prevent sports injuries including ankle injuries was created based on the scenarios. With the proposed smart wear, members of badminton clubs who may require assistance with sports injuries will be able to monitor said injuries, as well as their health condition, as avatars in visual games through a smart terminal. The visual game system will provide easier access to information about sports injuries and health. This smart sportswear will allow members of badminton clubs to prevent sports injuries and review their performance. This study can be utilized to design smart wear to prevent sports injuries and monitor sporting activities or bio-signals.