• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.436-438
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• 2003

Wind-induced oscillations are known to cause damage to the conductors and related hardware through fatigue, clashing of the bundled conductors and bolt loosening. Wake-induced oscillations have been known since the advent of bundled conductors, they are caused by aerodynamically unstable forces acting on the leeward conductors in the wake of the windward conductors, They take the form of horizontal galloping, snaking or rolling, in which case all subconductors move together in unison. They can also take the form of the subspan oscillation, which appear as elliptical motions of the subconductors moving out of phase, mainly in the horizontal plane within a subspan. In order to decrease amplitudes of the oscillation, this paper examines the application status of the spacer dampers and suggests proper installation methods.

• 방사성폐기물학회지
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• 제19권4호
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• pp.435-446
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• 2021

This article examines the consequences of a significant spent fuel management decision or event in the United States, South Korea and Taiwan. For the United States, it is the financial impact of the Department of Energy's inability to take possession of spent fuel from commercial nuclear power companies beginning in 1998 as directed by Congress. For South Korea, it is the potential financial and socioeconomic impact of the successful construction, licensing and operation of a low and intermediate level waste disposal facility on the siting of a spent fuel/high level waste repository. For Taiwan, it is the operational impact of the Kuosheng 1 reactor running out of space in its spent fuel pool. From these, it draws six broad lessons other countries new to, or preparing for, nuclear energy production might take from these experiences. These include conservative planning, treating the back-end of the fuel cycle holistically and building trust through a step-by-step approach to waste disposal.

• 한국운동역학회지
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• 제18권1호
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• pp.53-62
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• 2008

본 연구는 플랫폼 다이빙 종목 205B를 3차원 영상분석을 통하여 운동학적 분석을 하였다. 총소요시간은 평균 $1.112{\pm}0.12s$로 나타났으며 여유 있는 연기를 수행하기 위해 많은 소요시간을 확보하여야 할 것으로 사료된다, 이지시 신체중심의 높이는 평균 88.8cm이며 수평거리는 144.8cm, 수평, 수직속도는 평균 1.08m/s, 1.3m/s로 나타났으며, 회전동작은 높은 위치에서 수행해야 하며, 수평거리는 짧아야 입수자세에 유리 할 것으로 판단된다. 하지분절의 속도변화는 이지 시 속도가 감소한 이후 회전이 이루어지는 시점까지 상승하며 이지 순간에는 회전보다는 점프동작에 더 큰 영향을 미치며, 신체중심을 축으로 회전동작으로 이어지고 속도가 상승하는 것으로 판단된다. 몸통각속도는 이지 시에 크게 나타났는데, 이는 상 방향으로 점프하여 회전에 필요한 힘을 얻기 위해 상체분절을 최대한 곧게 펴고 신체중심을 높게 유지하여 도약을 해야 효과적인 동작을 수행 할 수 있기 때문으로 사료된다.

• 한국보건간호학회지
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• 제20권1호
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• pp.57-68
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• 2006

Purpose: To identify perimenstrual discomforts, coping and relief of symptoms in female workers. Methods: A convenience sample of 203 women who had worked were obtained from two hospitals in Busan. Data were collected through questionnaires from November 8 to 16, 2004. Three instruments were used in this study: the Perimenstrual Discomfort Questionnaire by Park(1988) and the Menstrual Coping Questionnaire and the Relief of Symptoms by Billings & Moos(1981) modified for this study. The data were analyzed by descriptive statistics, t-test, and ANOVA with SPSS 10.0 program. Results: The prevalence rate of dysmenorrhea was 81.3%. The total mean score for perimenstrual discomforts was 2.83 out of a possible total of 5 and the mean score for each category was, 3.08 for water retention, 2.95 for pain, 2.88 for negative affect, 2.83 for behavioral change, 2.73 for autonomic reactions, and 2.51 for concentration. According to these study results, statistical differences were found for age(F=2.76, p=0.04), feeling to menstruation(F=3.94, p=0.00), dysmenorrhea(t=4.26, p=0.00), and taking medication(t=2.09, p=0.00). The coping modes with the highest scores were 'take a hot bath'(99.0%)', 'rest and go to bed'(83.7%), 'regard menstruation as a physiological and temporary phenomenon'(76.8%), 'take a warm shower'(65.0%). The most frequently used methods to relieve symptoms were 'rest and go to bed'(70.0%), 'take a warm shower'(57.6%), 'take pain killers'(49.8%), 'apply hot water bag on painful parts of the body'(46.8%). Conclusion: Further research is needed to understand perimenstrual discomforts and the variables associated with them. Nursing intervention has to be considered in any program aiming to reduce perimenstrual discomforts.

• 한국치위생학회지
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• 제18권2호
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• pp.217-226
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• 2018

Objectives: The purpose of this study is to find out differences in oral health status, defined as their oral health and oral health quality of life among the elderly depending on their income and education levels. Methods: This study used 922 senior citizens over 65 from the data (2015) of the 6th National Health and Nutrition Survey (NHNS). The regression analysis was adopted to identify factors affecting their oral health status which has effect on their oral health quality of life. The statistical package SPSS 21.0 was employed. Frequency analysis, chi-squared analysis and regression analysis were used, and the significance level or Cronbach's alpha value was 0.05. Results: Depending on income levels, there were differences in their oral health status as to whether they use oral hygiene products, take dental examinations, join private health-insurances, and delay dental treatments or not. And educational levels also made significant differences in their oral health status as to whether they smoke, drink alcohol, how many times they brush teeth a day, whether they use oral hygiene products, take dental treatments, and join private health-insurances. Regression analysis on the relationship between their oral health status and the oral health quality of life showed that there were significant differences depending on whether they take dental treatments, delay dental medical treatments, smoke, take oral examinations, how many times they brush teeth a day, and whether they use oral hygiene products, or join private health-insurances. Conclusions: The study shows that a comprehensive plan is needed to raise attention on proper oral health-care and ultimately to improve the quality of life by considering the daily number of tooth brushing, oral hygiene product use, regular dental treatments, and other medical uses.

• 디지털융복합연구
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• 제20권1호
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• pp.327-334
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• 2022

본 연구는 국민들의 질환별 한방 치료효과 인식을 중심으로 한약 복용 의향에 미치는 영향을 분석하여 첩약(한약) 건강보험 시범사업의 원활한 추진 및 향후 본사업 확대 시 기초자료를 제공하고자 진행되었다. 자료는 2017 한방의 료이용 및 한약소비실태조사를 이용하였고, 일반국민 5,000명 중 응답을 완료한 3,032명을 대상으로 빈도분석, 교차분석, 로지스틱 회귀분석을 실시하였다. 로지스틱 회귀분석 결과, 소화기질환과 관절염에 대한 한방 치료효과 인식이 향후 한약 복용 의향에 유의한 영향요인으로 나타났다. 첩약(한약) 건강보험 시범사업이 한약을 제도권 내에 편입시키고, 한약의 질 관리를 통해 한약 치료의 대중화를 목표로 하고 있는 만큼, 한약 복용에 대해 수용성이 높은 소화기질환과 관절염을 대상 질환 확대 시 고려할 필요가 있다.

• 생물환경조절학회지
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• 제22권2호
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• pp.146-153
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• 2013

토마토 접목순화장치 개발을 위한 기초실험의 일환으로 대목의 종류 및 활착실내의 온습도가 접목활착율에 미치는 영향을 조사하였다. 접목활착실의 온도는 $23^{\circ}C>17^{\circ}C>20^{\circ}C>26^{\circ}C$ 순으로 초기 활착율과 최종활착율이 높은 것으로 조사 되었으며, 상대습도는 높을수록 활착율은 양호한 결과를 나타냈다. 단 상대습도가 90% 이상 처리구에서는 곰팡이병에 의한 이병주 발생도 같이 증가하는 경향을 나타냈다. 대목의 종류에 따른 초기활착율은 'Kanbarune'의 $26({\pm}1)^{\circ}C$와 'Solution'의 $20({\pm}1)^{\circ}C$를 제외하고는 대목의 종류와 관계없이 모든 온도 처리구에서 83% 이상 양호한 활착율을 보였으나, 최종 활착율에서는 처리 온도간에 뚜렷한 유의적 차이를 나타내, $23({\pm}1)^{\circ}C$에서만 대목의 종류와 관계없이 85%에서 90%전후의 활착율을 보였고, $20({\pm}1)$와 $26({\pm}1)^{\circ}C$에서는 65~75% 정도로 활착율이 저하되었다. 특히, $27({\pm}1)^{\circ}C$에서는 이병주의 증가로 건묘생산율은 모든 대목처리구에서 65% 이하였다. 일반적으로 알려져 있는 고온기 접목활착 최적온도인 $23({\pm}1)^{\circ}C$에서는 대목의 종류에 따른 건묘생산율은 84~88% 전후로 대목 품종간 유의적 차이는 없었다. 접목활착실내 상대습도 조건에 따른 최종 접목활착율은 초기 2~3일간은 상대습도를 90%로 유지하고 나머지 7~8일간은 75% 정도로 유지하는 처리구에서 100% 접목활착 성공율을 나타냈고, 전기간 90%로 유지한 처리구와 1일 90%, 9일간은 75%로 유지한 처리구에서는 90%전후의 성공률을 나타냈다. 전반적으로 높은 상대습도 유지기간이 길수록 초기 활착율은 증가하는 경향을 보였으나, 고습도에서 장기간 묘를 양생할 경우, 곰팡이병 발생 등으로 최종 건묘생산율은 감소하므로, 초기 2~3일간만 90% 전후로 유지하고 나머지 구간은 75% 전후로 유지하는 것이 고온기 토마토 접목 활착율 향상을 위한 바람직한 조건이라 판단되었다. 각 처리간 묘소질에는 큰 차이를 나타내지 않았으나, 전반적으로 활착율이 양호했던 처리구에서 묘소질이 타 처리구에 비해 상대적으로 좋았으며, 이러한 경향은 특히 근권부의 형태적 특성을 조사한 결과에서 명료하게 나타났다. 이상의 결과 고온기 토마토 활착실내의 환경관리는 23도 전후의 온도에서 $80({\pm}5)%$의 상대습도로 관리하는 것이 건묘생산에 적합할 것으로 판단되었다.

• 대한안전경영과학회지
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• 제6권4호
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• pp.155-170
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• 2004

Among the semiconductor If-chips, unlike memory chips, a majority of Application Specific IC(ASIC) products are produced by customer orders, and meeting the customer specified due date is a critical issue for the case. However, to the one who understands the nature of semiconductor manufacturing, it does not take much effort to realize the difficulty of meeting the given specific production due dates. Due to its multi-layered feature of products, to be completed, a semiconductor product(called device) enters into the fabrication manufacturing process(FAB) repeatedly as many times as the number of the product specified layers, and fabrication processes of individual layers are composed with similar but not identical unit processes. The unit process called photo-lithography is the only process where every layer must pass through. This re-entrant feature of FAB makes predicting and planning of due date of an ordered batch of devices difficult. Parallel machines problem in the photo process, which is bottleneck process, is solved with restricted roll out algorithm. Roll out algorithm is a method of solving the problem by embedding it within a dynamic programming framework. Restricted roll out algorithm Is roll out algorithm that restricted alternative states to decrease the solving time and improve the result. Results of simulation test in condition as same as real FAB facilities show the effectiveness of the developed algorithm.

• Advances in concrete construction
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• 제3권2호
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• pp.127-143
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• 2015

Steel fibre reinforced concrete (SFRC) is an anisotropic material due to the random orientation of the fibres within the cement matrix. Fibres under different inclination angles provide different strength contribution of a given crack width. For that the pull-out response of inclined fibres is of great importance to understand SFRC behaviour, particularly in the case of fibres with hooked ends, which are the most widely used. The paper focuses on the numerical modelling of the pull-out response of this kind of fibres from high-strength cementitious matrix in order to study the effects of different inclination angles of the fibres to the load-displacement pull-out curves. The pull-out of the fibres is studied by means of accurate three-dimensional finite element models, which take into account the nonlinearities that are present in the physical model, such as the nonlinear bonding between the fibre and the matrix in the early stages of the loading, the unilateral contact between the fibre and the matrix, the friction at the contact areas, the plastification of the steel fibre and the plastification and cracking of the cementitious matrix. The bonding properties of the fibre-matrix interface considered in the numerical model are based on experimental results of pull-out tests on straight fibres.

• East Asian Economic Review
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• 제27권3호
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• pp.213-242
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• 2023

This paper investigates whether the price of cryptocurrency is determined by the US dollar index, the price of investment assets such gold and oil, and the implied volatility of the KOSPI. Overall, the returns on cryptocurrencies are best predicted by the trading volume of the cryptocurrency both in-sample and out-of-sample. The estimates of gold and the dollar index are negative in the return prediction, though they are not significant. The dollar index, gold, and the cryptocurrencies seem to share characteristics which hedging instruments have in common. When investors take notice of the imminent market risks, they increase the demand for one of these assets and thereby increase the returns on the asset. The most notable result in the out-of-sample predictability is the predictability of the returns on value-weighted portfolio by gold. The empirical results show that the restricted model fails to encompass the unrestricted model. Therefore, the unrestricted model is significant in improving out-of-sample predictability of the portfolio returns using gold. From the empirical analyses, we can conclude that in-sample predictability cannot guarantee out-of-sample predictability and vice versa. This may shed light on the disparate results between in-sample and out-of-sample predictability in a large body of previous literature.