• 한국공작기계학회논문집
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• 제17권3호
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• pp.34-39
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• 2008

In this study, CFRP(Carbon Fiber Reinforced Plastics) that has high specific strength and elastic modulus and low thermal strain was used as a material for the lightweight structural member. CFRP is a fiber material as anisotropic material. The anisotropic material is characterized by the change of its mechanical properties according to stacking orientation angle. CFRP orientation angle was oriented in [A/B]s in order to examine the effect of CFRP orientation angle on the characteristics of energy absorption. CFRP is very weak to the impact from the outside. So, when impact is applied to CFRP, its strength is rapidly lowered. The hybrid material was manufactured by combining CFRP to aluminum which is lightweight and widely used for structural members of the automobile. The hybrid member was shaped as a side member that could support the automobile engine and mount and absorb a large amount of impact energy at the front-end in case of automobile collision. The bending test device was manufactured in accordance with ASTM standard, and mounted to UTM for bending test. For comparing bending characteristics of the hybrid member with those of Aluminum and CFRP member, tests were performed for aluminum, CFRP and hybrid member, respectively.

• Journal of Information Display
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• 제8권1호
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• pp.22-25
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• 2007

Stereoscopic/autostereoscopic systems have been developed to express 3D images, but have not been successfully use in practise. In order to apply 3D display to promising applications such as advertisements and games, we developed a 42" 2D/3D switchable display. It has characteristics that do not require special glasses for 3D images, uses multi-view technology for improving 3D viewing characteristics, and has a 2D/3D switching function to express dynamic 3D contents as well as conventional 2D contents.

• Steel and Composite Structures
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• 제4권6호
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• pp.419-435
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• 2004

The safety level of a structural system designed per code specifications can not be inferred directly from the reliability of members due to the load redistribution and nonlinear inelastic structural behavior. Comparison of the system and member reliability, which is scarce in the literature, is likely to indicate any possible inconsistency of design codes in providing safe and economical designs. Such a comparative study is presented in this study for moment resisting two-dimensional steel frames designed per AISC LRFD Specifications. The member reliability is evaluated using the resistance of the beam-column element and the elastic load effects that indirectly accounts for the second-order effects. The system reliability analysis is evaluated based on the collapse load factor obtained from a second-order inelastic analysis. Comparison of the system and member reliability is presented for several steel frames. Results suggest that the failure probability of the system is about one order of magnitude lower than that of the most critically loaded structural member, and that the difference between the system and member reliability depends on the structural configuration, degree of redundancy, and dead to live load ratio. Results also suggest that the system reliability is less sensitive to initial imperfections of the structure than the member reliability. Therefore, the system aspect should be incorporated in future design codes in order to achieve more reliability consistent designs.

• 한국안전학회지
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• 제31권3호
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• pp.68-74
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• 2016

This paper presents a new strengthening method of underground box structures against seismic loads for anti-seismic capacity improvement. A threaded steel member with pressure devices(so called 'Pre-flexed member system') is used to improve seismic capacity of the RC box structure. The pre-flexed member system is fixed the corner of opening after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. Two bracing types of strengthening methods were used; conventional bracing method and I-bracing pressure system. For the performance evaluation, seismic analyses were performed on moment and shear resisting structures with and without strength member system. Numerical results confirmed that the proposed pre-flexed member system can enhance the seismic capacity of the underground RC box structures.

• 대한안전경영과학회지
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• 제6권1호
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• pp.269-281
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• 2004

This study aims to examine the effects of team member characteristics(change reception, work understand) and team process(potency, social support, workload sharing, communication and cooperation within the team) to team effectiveness(job commitment, job satisfaction and productivity), As the result, both team member characteristics and team process have positive relations with team effectiveness.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.571-574
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• 1999

Due to many advantages of advanced composite material, research on the composite compression member is initiated. In this paper structural characteristics of concrete filled glass fiber reinforced composite tubular member si studied. Experimental results shows that strength and ductility of composite compression member is considerably increased due to concrete confinement action of composite surface. Thus it can be anticipated that increased strength of concrete will be incorporated in the design of composite compression member.

• 한국산업융합학회 논문집
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• 제5권3호
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• pp.261-268
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• 2002

In this paper, the shape optimization is considered over the upper slab of reinforced concrete culvert. The sequential linear programming method (SLP) is used as a rational approach to this shape optimization. To make a comparison between the arch shaped member and the straight member for the upper slab, the culverts with 5~20m earth height were adopted. It is shown that the optimum rise/span is about 7%-13%, and the arch shaped member is more cheap (over 10%) than the straight member for the construction cost.

• Journal of Information Display
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• 제8권3호
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• pp.17-21
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• 2007

We introduce a new electrode structure for the patterned vertical alignment (PVA) mode, which has a lower color-shift at large viewing angle than the one-domain VA mode. By manipulating the period of electrode structure, we can make more multi-domains and use the existing fabrication processes without having to use additional materials.

• 한국과학교육학회지
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• 제35권2호
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• pp.333-342
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• 2015

과학 탐구 활동은 학습자들 간의 협동학습을 통해 문제를 해결하는 학습 방법이다. 학습자 중심의 상호작용을 전제로 한 과학 탐구 활동을 구조적 차원에서 분석하는 것이 필요하다. 사회네트워크 분석법은 구성원들의 상호작용을 분석하는데 주로 사용되는 방법이다. 본 연구는 5인 1조 31개 조로 구성된 과학영재들을 대상으로 소집단 과학 탐구실험 활동에서 나타난 구성원 간의 상호작용의 양상을 수치적 특성을 바탕으로 유형화하였다. 이 연구의 결과는 다음과 같다. 과학영재들의 상호작용 유형은 모두 여덟 가지로 나타났다. 이 중 가장 많은 상호작용 유형은 전체 31개 조 중 모두 9개 조에서 나타나 29%를 차지한 유형 1로 세 명의 구성원이 상호작용 하는 경우였다. 이들 유형은 다시 한 구성원을 중심으로 나머지 구성원들이 모두 연결 관계를 형성하는 참여형과 중심적 역할을 하는 구성원이 없이 소외된 구성원이 존재하는 소외형으로 구분할 수 있다. 참여형은 유형 4, 유형 6, 유형 7, 유형 8로 모두 9개(29%) 조에서, 소외형은 유형 1, 유형 2, 유형 3, 유형 5로 모두 22개(71%) 조에서 나타났다. 즉, 한 구성원을 중심으로 모든 구성원이 상호작용에 참여하는 형태보다는 중심적 역할을 하는 인물 없이 일부 소외된 구성원이 존재하는 가운데 나머지 구성원들이 상호작용하는 유형이 대부분을 차지하였다. 이 연구를 바탕으로 과학 탐구활동에 적절한 집단의 크기는 무임승차효과나 소외된 학생이 없을 것으로 생각되는 3명이 가장 효과적이라고 할 수 있다. 또한 중심 구성원의 유무에 따라서는 있는 경우가 더 효과적일 것으로 사료된다.

• 대한의료기공학회지
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• 제17권1호
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• pp.24-51
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• 2017

Objective : The purpose of this study is to introduce Whidam's Su-Gi therapy(WST.) as a remarkable traditional manual therapy. Main subject : WST. is a traditional manual therapy from Do-In(導引) An-Kyo(按蹻) that treats disease by controlling Gi(Gi-Gong therapy). It makes treatment effects by pushing Sa-Gi(邪氣) which becomes aggregation-accumulation(積聚) to right places by using pointillage, stroking, and rubbing with doctor's focused intention(意念). The cervical spine connects body and brain, so treating cervical spine could be a foundation of all treatment. Discussion : WST. is a manual therapy that treats not only muscles, nerves, vessels, joints but also Oriental medicine concept-meridian, acupoint and Gi(氣). Conclusions: 1) WST. is a traditional manual therapy using Gi-Gong, 2) WST. changes Sa-Gi(邪氣) into Jung-Gi(正氣), which means curing aggregation-accumulation(積聚), 3) Cervical WST. treats a passage that connects upper and lower parts of human body; heart and brain, and 4) Cervical WST. is a treatment to activate So-Ju-Cheon(小周天), which controls human body immunity.