• 콘크리트학회논문집
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• 제27권5호
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• pp.521-530
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• 2015

최근 개발중인 초고강도 또는 강섬유보강 초고강도 콘크리트는 현행 설계기준으로 설계할 경우 그 안전성에 대해 별도의 실험 또는 해석적 증명이 필요하다. 이를 위한 철근콘크리트 부재의 상세 해석에는 응력-변형률 관계의 정의가 필요하다. 이를 위해 본 연구에서는 현행 설계기준의 제한 범위를 벗어나는 강섬유보강 초고강도 콘크리트의 압축응력하에서의 기계적 특성을 정의하였다. 80~200 MPa 의 압축강도를 보유한 분체 콘크리트 매트릭스에 강섬유를 혼입하였으며, 섬유의 보강량에 따른 압축강도의 증진률에 대해 분석하고 압축강도에 따른 탄성계수와 최대응력 발현시의 변형률에 대해 조사 분석하였다. 넓은 콘크리트 압축강도 범위내에서 사용성 확보를 위해 기존 연구결과로부터 수집된 압축강도 증진률, 탄성계수, 최대응력 발현시 변형률의 크기에 대한 결과를 활용하여 기존 추정식의 평가를 수행하였다. 또한, 강섬유가 보강되어 있지 않은 매트릭스에 대한 기존 추정식 중 정확도가 높은 식을 기반으로, 강섬유의 영향을 반영할 수 있는 새로운 추정식을 위한 계수를 도출하였다.

• 한국산학기술학회논문지
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• 제13권7호
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• pp.2878-2885
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• 2012

본 연구에서는 MR유체를 특징으로 하는 하지 재활운동 기구를 제안하고, 재활운동 기구에 적용하기 위한 소형 MR 유체 브레이크를 설계, 제작하여 성능을 평가하였다. MR유체 브레이크의 저항 특성은 MR유체에 부하되는 자기장의 변화에 의해 제어된다. 공간 제한을 고려하여 자기장 세기와 관련된 설계변수는 유한요소 프로그램인 ANSYS Workbench를 사용하여 최대 토오크가 발생할 수 있도록 결정하였다. 제안된 MR유체 브레이크를 제작하고, 자기장에 따른 토오크의 변화를 실험적으로 평가하였다. 전류를 공급하면, MR 유체 브레이크의 토오크는 증가하였으며, 그 반응은 매우 빠르게 나타났다. 공급하는 전류의 세기가 증가함에 따라 MR 유체 브레이크의 토오크는 MR유체의 빙햄 특성과 유사하게 증가하여 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3279-3286
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• 2014

Background: Cancer is one of the leading causes of death in Korea. To reduce cancer incidence, the Korean National Cancer Center (KNCC) has been expanding its organized cancer screening program. In addition, there are opportunistic screening programs that can be chosen by individuals or their healthcare providers. The purpose of this study was to investigate factors associated with participation in organized and opportunistic cancer screening programs, with a particular focus on socioeconomic factors. Materials and Methods: We used data from the Korea National Health and Nutrition Examination Survey (KNHANES), a cross-sectional nationwide study conducted by the Korean Ministry of Health and Welfare from 2007 to 2011. The study included information from 9,708 men and 12,739 women aged 19 years or over. Multinomial logistic regression analysis was conducted, adjusting for age, year of data collection, residential region, current smoking status, current alcohol consumption status, exercise, marriage status, job status, perceived health status, stress level, BMI, limitation of activities, cancer history, health insurance type, and private insurance status, to investigate the association between education level, economic status, and cancer screening participation. Results: In terms of education level, disparities in attendance were observed only for the opportunistic screening program. In contrast, there was no association between education level and participation in organized screening. In terms of economic status, disparities in opportunistic screening participation were observed at all income levels, but disparities in organized screening participation were observed only at the highest income level. Conclusions: Our findings reveal that socioeconomic factors, including educational level and economic status, were not significantly associated with participation in organized cancer screening, except at the highest level of income.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 2001년도 제40차 춘계학술대회 및 연수교육
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• pp.24-34
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• 2001

Restenosis remains a major limitation of percutaneous coronary interventions. Numerous studios including pharmacological approaches and new devices failed to reduce the restenosis rate except coronary stenting. Since the results of $BENESTENT^{1)}\;and\;STRESS^{2)}$ studies came out, coronary stenting has been the most popular interventional strategy in the various kinds of coronary stenotic lesions, although the efficacy of stenting was shown only in the discrete lesion of the large coronary artery. The widespread use of coronary stenting has improved the early and late outcomes after coronary intervention, but it has also led to a new and serious problem, e.g., in-stent restenosis. Intravascular radiation for prevention of restenosis is a new technology in the field of percutaneous coronary intervention. Recent animal experiments and human trials have demonstrated that local irradiation, in conjunction with coronary interventions, substantially diminished the rate of restenosis. This paper reviews basic radiation biology of intracoronary radiation and its role in the inhibition of restenosis. The current status of intracoronary radiation therapy using Re-188 liquid balloon is also discussed.

• ALGAE
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• 제27권2호
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• pp.109-114
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• 2012

Water motion is one of the main drivers in morphological variability in species within de order Laminariales, and most of our current knowledge is based on subtidal populations. $Eisenia$ $arborea$ is a dominant kelp species in the North Pacific, widely distributed along the Baja California Peninsula from mid intertidal down to subtidal areas. This species presents great variability in the intertidal zone but it has not been yet evaluated such variability according to wave exposure. The present work also identifies the spatial / temporal variation, particularly respect to the presence of stipes without medulla (hollow stipes) a feature common among other brown seaweeds. We evaluated the effects of wave action in morphological variation of intertidal $Eisenia$ $arborea$ (Laminariales, Ochrophyta) at Punta Eugenia. The spatial and temporal variation sampling was surveyed between February, May, July, and August 2004 in the intertidal of Punta Eugenia, Baja California Sur. Our results have shown that exposed sites correlate with increased length and width of stipes as compared to more protected sites. Hollow stipes frequency changed more in association with temporal variation than with spatial heterogeneity suggesting nutrient limitation for thalli development. Our results suggest that $Eisenia$ $arborea$ compensate by morphological modifications the stress of living in the intertidal zone by showing larger stipes. Hollow stipes might be are also a mechanical adaptation to increase survival in high energy environments.

• 한국가정과교육학회지
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• 제4권1호
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• pp.43-55
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• 1992

The purpose of this reasearch is to supply the basic data to improve Home Economics curriculum. This research was intended for 190 home economics teachers who are teaching in Kwang-Ju and chun-nam. The results are summarized as follows； 1. Among the objects of Home economics, the most important objects were to make students understand the significance of family life and development of family numbers. It requires 4 or 5 hours a week to learn these objects. 2. The amount of curriculum was immense and the level of curriculum was higher than students’level. More intencifying field are in this order； sex education, propriety education, consumption life, occupation, and computer education. 3. In home economics curriculum, the main stress was laid upon the application of action and learning content was focused on the matter set in the examination. 4. Theory and practical training classes were usually in the ratio of 7：3 and 8：2 in the current school classes. Ideal training classes are in the ration of 4：6, 5：5, 6：4, which showed that much weight was given to the practical exercises. 5. In practing subject matter, students tended to practice only main subject matter. The reason was primarily due to the lacks of equipments and faccilities, the limitation of training time for enterance examination and budgetary deficit. 6. Application of resorces was in the order of files, realia, samples, hanging chart, O.H.P and V.T.R. 7. The method of evaluation was mostly composed of paper and pens and practical evaluation when the practical evaluation was carrient out, in the case of necessity the standard of evaluation was made out.

• 대한족부족관절학회지
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• 제26권2호
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• pp.95-102
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• 2022

Purpose: This study was based on the Korean Foot and Ankle Society (KFAS) member survey and aimed to report the current trends in the management of syndesmotic injuries over the last few decades. Materials and Methods: A web-based questionnaire containing 36 questions was sent to all KFAS members in September 2021. The questions were mainly related to the preferred techniques and clinical experiences in the treatment of patients with syndesmotic injuries. Answers with a prevalence ≥50% of respondents were considered a tendency. Results: Seventy-six (13.8%) of the 550 members responded to the survey. The results showed that the most preferred method to diagnose a syndesmotic injury was magnetic resonance imaging (MRI). Intraoperatively, the external rotation stress test and the Cotton test were most frequently used to confirm syndesmotic diastasis. The reduction was usually done by a reduction clamp. One 3.5-mm screw was used most frequently over three cortices at 2~4 cm above the ankle joint. The preferred ankle position during fixation was 0° dorsiflexion. Removal of the syndesmotic screw was routinely done by most surgeons, mainly because of the limitation of movement and risk of screw breakage. Factors that affect suture button selection included non-rigid fixation which enables adequate fixation, early weight-bearing, and an infrequent need to remove the hardware. Inadequate reduction was considered the main factor that affects poor prognosis. Conclusion: This study proposes updated information about the current trends in the management of syndesmotic injuries in Korea. Consensuses in both the diagnostic and therapeutic approach to patients with syndesmotic injury were identified in this survey study. This study may raise the awareness of the various possible approaches toward the injury and should be used to further establish a standard protocol for the management of syndesmotic injuries.

• 콘크리트학회논문집
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• 제27권6호
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• pp.615-623
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• 2015

철근콘크리트 전단벽의 전단강도를 예측하기 위한 기존 연구자들의 스트럿-타이 모델(STM)들은 횡하중 및 상부의 축력에 대한 전단벽의 내부 힘의 흐름과 웨브의 전단철근에 의해 전달되는 전단력의 비율을 명확히 제시하고 있지 않다. 이를 개선하기 위해서, 이 연구에서는 콘크리트 파괴역학의 균열 띠 이론을 기반한 단순한 STM을 개발하였다. 응력이완 스트립을 동반하는 콘크리트 스트럿의 등가유효너비는 중립축 깊이와 콘크리트 유효압축강도 계수로 결정되었다. 균열 띠 확장영역의 전단 전달 메커니즘은 강성법에 의한 트러스 작용으로부터 산정되었다. 웨브 콘크리트 스트럿과 전단철근에 의한 전단 전달력은 응력이완 스트립과 균열 띠 이론을 기반한 에너지평형조건으로부터 유도되었다. 제시된 모델은 Siao와 Hwang et al.의 STM에 비해 150여개의 기존 실험결과의 경향을 잘 예측하였다. 또한, 제시된 STM은 각 변수에 따른 무차원된 전단강도의 경향을 잘 반영하고 있다.