• International Journal of Aeronautical and Space Sciences
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• 제14권1호
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• pp.46-57
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• 2013

Flutter stability and buffeting response have been the topics of most concern in the design state of long-span suspension bridges. Among approaches towards the aerodynamic stability, the aerodynamic-based control method which uses control surfaces to generate forces counteracting the unstable excitations has shown to be promising. This study focused on the mechanically controlled system using flaps; two flaps were attached on both sides of a bridge deck and were driven by the motions of the bridge deck. When the flaps moved, the overall cross section of the bridge deck containing these flaps was continuously changing. As a consequence, the aerodynamic forces also changed. The efficiency of the control was studied through the numerical simulation and experimental investigations. The values of quasi-steady forces, together with the experimental aerodynamic force coefficients, were proposed in the simulation. The results showed that the passive flap control can, with appropriate motion of the flaps, solve the aerodynamic instability. The efficiency of the flap control on the full span of a simple suspension bridge was also carried out. The mode-by-mode technique was applied for the investigation. The results revealed that the efficiency of the flap control relates to the mode number, the installed location of the flap, and the flap length.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 제35회 춘계학술대회
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• pp.169-176
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• 2002

Axial crushing behavior of cylindrical shell Is utilized in the braking of the high-velocity impacting object. In this paper, truncated cone shape brake device is introduced. That is, thickness of the shell is increased gradually from the impacting end to the other end. A detailed experimental investigation on the quasi-static axial crushing behavior of truncated cone type brake devices has been performed. Specimens of various shape were tested to check the influence of design parameters such as length, radius, mean thickness, and conical angle of cylinder. Influence of the material properties were also investigated by adopting aluminum, low carbon steel, and stainless steel as constructing materials. By analyzing deformation procedures of the specimens, it is seen that conical angle influence the deformation mode and the sequence of the wrinkles generation. Braking distance and mean braking force of each specimen were predicted based on the crushing load measured from the tests.

• 노동경제논집
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• 제23권2호
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• pp.107-126
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• 2000

본 연구는 훈련을 받지 않은 실직자들로 비교집단을 구성하여 훈련을 받은 실직자들과 함께 추적조사를 실시함으로써, 훈련을 받지 않았을 경우의 가상적인 결과와 비교하여 훈련의 성과를 추정하는 준실험적인 평가를 하였다. Cox모형을 통한 추정결과, 훈련참여는 실직자의 재취업 확률을 유의하게 높이는 효과를 가진다. 그러나 훈련내용은 재취업 확률에 유의하게 영향을 미치지 않은 것으로 나타났다. 또한 훈련 참여자가 수강한 훈련 관련분야로의 재취업은 매우 미흡한 것으로 조사되었다. 이는 실업자재취직훈련이 노동시장에서의 이탈을 억제하여 재취업을 촉진하는 효과를 가지지만, 취업능력의 제고를 통한 안정적인 일자리로의 재취업이라는 적극적 노동시장정책의 수행에는 아직 미흡함을 시사한다.

• Perspectives in Nursing Science
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• 제13권2호
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• pp.59-69
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• 2016

Purpose: This paper is a review of interventions designed to promote self-awareness in the nursing area. The specific purpose was to analyze the general characteristics of self-awareness intervention studies, intervention contents, and the effects of the studies in order to present basic information for developing self-awareness interventions in the nursing area. Methods: Using "nurse/nursing" and "self-awareness" as key words, the researchers searched six electronic databases. The method proposed by Whittemore and Knafl was used. Results: Seventeen studies met the inclusion criteria. The most common research design was quasi-experimental. Nine quasi-experimental studies (52.9%), 7 qualitative studies (41.2%), and 1 mixed methodology study (5.9%) were analyzed. Most studies used group intervention and student nurses as participants. The interventions were revealed to be effective in enhancing participants' self-awareness. The reflection method was used in most intervention approaches. Conclusion: To provide therapeutic nursing care, having self-awareness is important. Future research with well-designed clinical trials applying self-awareness intervention needs to be conducted to enhance self-awareness in the nursing area.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.974-987
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• 2021

This paper presents ductile fracture simulation of full-scale cracked pipe for nuclear piping materials using the cohesive zone model (CZM). The main objective of this study is to investigate the applicability of CZM to predict ductile fracture of cracked pipes with various crack shapes and under quasi-static/dynamic loadings. The transferability of the traction-separation (T-S) curve from a small-scale specimen to a full-scale pipe is demonstrated by simulating small- and full-scale tests. T-S curves are calibrated by comparing experimental data of compact tension specimens with finite element analysis results. The calibrated T-S curves are utilized to predict the fracture behavior of cracked pipes. Three types of full-scale pipe tests are considered: pipe with circumferential through-wall crack under quasistatic/dynamic loadings, and with 360° internal surface crack under quasi-static loading. Computational results using the calibrated T-S curves show a good agreement with experimental data, demonstrating the transferability of the T-S curves from small-scale specimen.

• 지역사회간호학회지
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• 제14권1호
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• pp.16-23
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• 2003

Purpose: The purpose of this study was to investigate the effects of music therapy on depression, balance, and flexibility in the elderly. An experimental group consisting of 23 people, was given music therapy for 90 minutes per a week for 6 weeks, while a control group consisting of 21 people, was not given music therapy with quasi-experimental design. Result: The result of the study show that music therapy is effective for decreasing depression and improving flexibility in the elderly. However, this study found no significant differences in balance between the experimental and the control groups. Conclusion: Despite one part, nursing intervention of music therapy to adapt Rhythm for Life elevated the strength of the elderly's body and showed decrease in depression. Therefore the Music therapy Program improves the quality of life in the elderly.

• 임상간호연구
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• 제15권2호
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• pp.57-65
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• 2009

Purpose: This study was conducted to examine the effects of Brain Death Organ Donation Education on nurses' knowledge and attitudes. Methods: It is a quasi-experimental study using the non-equivalent control group. A total of 100 nurses participated in the study; 50 in the experimental group, and the rest in control group. Collected data were analyzed using ${\chi}^2-test$, t-test and ANCOVA by SPSS 12.0 program Results: There was a statistically significant difference in knowledge (F=13.29, p<.001), and attitude (F=4.35, p=.040) after the experimental group received Brain Death Organ Donation Education. Conclusion: The Brain Death Organ Donation Education was revealed as an effective tool in improving nurses' knowledge and attitudes toward organ donation.

• 한국사회복지학
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• 제61권4호
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• pp.5-33
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• 2009

본 연구는 교육과학기술부에서 실시하고 있는 빈곤 아동 청소년 정책인 '교육복지투자우선지역 지원사업'(이하 교육복지사업)의 정당성 확인과 지속적 실시 여부를 확인해 보기 위해 사업의 성과를 평가하고자 하였다. 특히 교육복지사업에서 기대되는 성과지표에 기반하여 사회 정서적 발달('긍정적인 자아개념', '우울 불안 자살충동', '공격성 분노', '비행', '학교생활적응', '사회적 변화')과 인지적 발달('학습자기조절인지', '학습행동통제전략', '직업준비성')을 측정하고자 하였다. 이를 위해 교육복지사업을 운영하는 학교[즉, 실험집단]와 동일한 지역 내 열악한 환경에 놓여 있는 비운영학교[즉, 통제집단] 간 비교 그리고 사업운영학교의 서비스 이용수준에 따른 실험집단 내 분석을 실시하였다. 이러한 연구결과로부터 교육복지사업이 성과지표에 긍정적인 효과가 있음을 확인할 수 있었다. 또한 열악한 환경이라는 위험요인에 대한 완충효과를 갖는 동시에 서비스제공에 상승효과를 나타내는 '학교 건강성'의 조절효과 확인을 통해 교육복지실천에 유용한 정보를 제공할 수 있었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.191-194
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• 2003

The results from a systematic study of the response of a Ti-6Al-4V alloy under quasi-static and dynamic loading at different strain rates and temperatures are presented. It has been shown that the work-hardening rate decreased as the strain rate and the strain increased. The correlations and predictions using modified KHL (Khan-Huang-Liang) viscoplastic constitutive model are compared with those from JC (Johnson-Cook) model and experimental observations. Overall, KHL model correlations and predictions compared much more favorably than the corresponding JC model predictions and correlations.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.877-882
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• 2001

Lap splice in plastic hinge region of RC bridge piers is inevitable because of the constructional joint between footing and column. RC circular columns with lap-splice in plastic hinge region are widely used in Korean highway bridges. It is, however, believed that there are not many experimental research works for nonlinear behavior of these columns subjected to earthquake motions. This study has been performed to verify the effect of axial force, lap splice and confinement steel ratio for the seismic behaviour of reinforced concrete bridge piers. Quasi-static test have been done to investigate the physical seismic performance of RC bridge piers, such as displacement ductility and enemy absorption.