• 한국항해항만학회지
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• 제39권4호
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• pp.361-370
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• 2015

풍력에너지는 20여년 전부터 새로운 대체 연료로서 주목받기 시작하여 현재는 글로벌 비즈니스 모델로 성장하고 있다. 전 세계적으로 풍력발전이 차지하는 비율은 전체 발전량의 30%를 차지하며, 이 비율은 지난 10여 년 간 꾸준히 증가해 왔다. 근래에 들어 일반 발전방식들의 탄소 배출량 증가 및 온실효과로 인한 환경문제 등으로 인해 풍력발전에 대한 국제적 수요는 점차 커져가고 있다. 본 연구에서는 이러한 풍력 발전용 부품에 대한 효율적인 운송경로를 제안하기 위해 풍력 발전용 부품의 운송 특성에 따라 그 경로를 접근성 우선 경로, 경제성 우선 경로, 편의성 우선 경로 등으로 분류하였다. 본 연구를 통해 풍력발전부품 제조업체들은 제품의 운송기간의 문제 뿐 아니라 운송경로의 효율성과 경제성까지 판단할 수 있게 되었다. 즉 지금까지 선박회사나 포워더를 통해 이루어지던 운송경로의 결정을 제조업체도 해당 운송경로의 효율성과 경제성을 분석하고 비교할 수 있게 되었다.

• Advances in Computational Design
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• 제4권2호
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• pp.73-90
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• 2019

The growth in the number of single-member households is a critical issue worldwide, especially among the elderly. For those living alone, who may be unaware of their health status or routines that could improve their health, a continuous healthcare monitoring system could provide valuable feedback. Assessing the performance adequacy of activities of daily living (ADL) can serve as a measure of an individual's health status; previous research has focused on determining a person's daily activities and extracting the most frequently performed behavioral patterns using camera recordings or wearable sensing techniques. However, existing methods used to extract common patterns of an occupant's activities in the home fail to address the spatio-temporal dimensions of human activities simultaneously. Though multiple sequence alignment (MSA) offers some advantages - such as inherent containment of the spatio-temporal data in sequence format, and rapid identification of hidden patterns - MSA has rarely been used to extract in-home ADL routines. This research proposes a method to extract a household occupant's ADL routines from a cumulative spatio-temporal data log of occupancy collected using a non-intrusive method (i.e., a tomographic motion detection system). The findings from an occupant's 28-day spatio-temporal activity log demonstrate the capacity of the proposed approach to identify routine patterns of an occupant's daily activities and to reveal the order, duration, and frequency of routine activities. Routine ADL patterns identified from the proposed approach are expected to provide a basis for detecting/evaluating abrupt or gradual changes of an occupant's ADL patterns that result from a physical or mental disorder, and can offer valuable information for home automation applications by enabling the prediction of ADL patterns.

• 한국임상약학회지
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• 제31권2호
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• pp.115-124
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• 2021

Background: With an increase in the number of breast cancer survivors, greater importance is attached to health-related quality of life, particularly pain and symptom control. This study aimed to identify the factors that are associated with pain in cancer patients based on the patterns of prescribing opioid, non-opioid, and adjuvant analgesics. Methods: This analysis included new patients who had developed breast cancer between 2003 and 2012. The degree of pain was analyzed based on the socio-demographic (age, income quintile, number of hospitalizations, and duration of disease), indicator (Body Mass Index; BMI, Charlson Comorbidity Index; CCI, Cumulative Analgesic Consumption Score; CACS), operation (mastectomy, lymph node dissection), and therapy (chemotherapy, radiation therapy), as well as complication-related variable (lymphedema). Results: As for the patterns of prescribing analgesics by stages, non-opioid and opioid analgesics constituted 30.7 and 69.3%, respectively. The mean value and variance of CACS were 5.596 and 12.567, respectively. The factors that significantly affected the degree of pain were age (≥50; IRR: 1.848, 95% CI 1.564-2.184, p=0.000), income quintile (IRR: 0.964, 95% CI 0.938-0.991, p=0.008), BMI (≥ 25; IRR: 1.479, 95% CI 1.222-1.795, p=0.000), CCI (≥ 4; IRR: 1.649, 95% CI 1.344-2.036, p=0.000), and lymphedema (yes; IRR: 1.267, 95% CI 1.006-1.610, p=0.047). Conclusions: It is necessary to develop systematic and comprehensive pain control measures to improve the quality of life for breast cancer survivors, especially for those who are 50 years or older, lie in the lower-income quintile, have BMI of ≥25 and CCI score ≥ 4, or have lymphedema.

• Journal of Preventive Medicine and Public Health
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• 제54권2호
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• pp.153-159
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• 2021

Objectives: Life course exposure to passive smoke may predict health, but there are few validated measures. We tested the reliability and validity of a retrospective life course passive smoking questionnaire. Methods: Participants from the third follow-up of the Childhood Determinants of Adult Health study (2014-2019, ages 36-49 years) retrospectively reported mother/father/other household member smoking when living at home during childhood, including duration (years) and smoking location (never/sometimes/always inside house). The severity of exposure index (SEI; sum of mother/father/other years smoked multiplied by smoking location), cumulative years of exposure (CYE; sum of mother/father/other years), and total household smokers (THS) were derived. The reliability of retrospective passive smoking reports was examined with intraclass correlation coefficients (ICCs) using household smoking reported 34 years earlier in 1985 by participants when aged 7-15 years. Construct validity was examined by correlating retrospective passive smoking with participants' smoking in adulthood and lung function in childhood and adulthood. Results: Among 2082 participants (mean±standard deviation [SD], 45.0±2.5 years; 55.2% females), THS ranged from 0 to 5 (mean±SD, 0.9±1.0), CYE ranged from 0 to 106 (mean±SD, 10.5±13.9), and SEI ranged from 0 to 318 (mean±SD, 24.4±36.0). Retrospective measures showed moderate agreement with total household smokers reported in childhood (ICC, 0.58 to 0.62). The retrospective measures were weakly but significantly (p<0.05) correlated with participants' smoking (r=0.13 to 0.15) and lung function (r= -0.05 to -0.06). Conclusions: The retrospective passive smoking questionnaire showed reasonable reliability and validity. This measure may be useful for epidemiological studies.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.99-99
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• 2020

The frequency and scale of domestic flood damage continues to increase, but the criteria for responding to flood damage have not been established. To this end, research is underway to estimate the amount of rainfall in each region so that it can be used to respond to flood damage. The limit rainfall is defined as the cumulative maximum rainfall for each duration that causes flooding, and this research purpose to improve the threshold rainfall by estimating the damage based on the damage history in units of 5 years and analyzing changes over time. The limit rainfall based on the damage history was estimated by using the NDMS past damage history of the Ministry of the Interior and Safety and the rainfall minutes data of AWS and ASOS. The period for estimating the limit rainfall is 2013 ~ 2017, 2015 ~ 2019, and the limit rainfall is estimated by analyzing the relationship between the flood damage history and the rainfall event in each period. Considering changes in watershed characteristics and disaster prevention performance, the data were compared using 5-year data. As a result of the analysis, the limit rainfall based on the damage history could be estimated for less than about 10.0% of the administrative dongs nationwide. As a result of comparing the limit rainfall by period, it was confirmed that the area where the limit rainfall has increased or decreased This was analyzed as a change due to rainfall events or urbanization, and it is judged that it will be possible to improve the risk criteria of flooding.

• 대한토목학회논문집
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• 제29권2B호
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• pp.155-162
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• 2009

단변량 빈도해석법은 수공구조물 설계에 널리 사용되고 있다. 하지만 호우사상은 강우량, 최대강우강도, 강우지속기간과 같은 특성으로 표현되기 때문에 단변량 빈도해석법으로는 그 특성을 종합적으로 표현하는데 한계가 있을 수 있다. 이러한 호우사상의 특성들을 함께 표현해 줄 수 있는 이변량 빈도해석법의 사용이 수공구조물의 설계에 필요하다. 본 연구는 서울 강우관측소의 46개년(1961~2006) 시 강우자료를 Gumbel 혼합모형에 적용하여 빈도해석을 수행하였다. 이변량 강우빈도해석을 통해 결합누적분포함수를 산정한 후, 결합재현기간, 그리고 조건부 재현기간을 산정하였다. 이와 같은 이변량 강우빈도해석은 다양한 호우특성들에 대한 확률적 거동에 대한 예측정보를 제공함으로써 수공구조물의 계획 및 설계 그리고 위험도 평가 등의 문제 해결에 유용하게 사용될 수 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.516-516
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• 2022

Agricultural reservoirs are critical water resources structures to ensure continuous water supplies for rice cultivation in Korea. Climate change has increased the risk of reservoir failure by exacerbating discrepancies in upstream runoff generation, downstream irrigation water demands, and evaporation losses. In this study, the variations in water balance components of 400 major reservoirs during 1973-2017 were examined to identify the reservoirs with reliable storage capacities and resilience. A conceptual lumped hydrological model was used to transform the incident rainfall into the inflows entering the reservoirs and the paddy water balance model was used to estimate the irrigation water demand. Historical climate data analysis showed a sharp warming gradient during the last 45 years that was particularly evident in the central and southern regions of the country, which were also the main agricultural areas with high reservoir density. We noted a country-wide progressive increase in average annual cumulative rainfall, but the forcing mechanism of the rainfall increment and its spatial-temporal trends were not fully understood. Climate warming resulted in a significant increase in irrigation water demand, while heavy rains increased runoff generation in the reservoir watersheds. Most reservoirs had reliable storage capacities to meet the demands of a 10-year return frequency drought but the resilience of reservoirs gradually declined over time. This suggests that the recovery time of reservoirs from the failure state had increased which also signifies that the duration of the dry season has been prolonged while the wet season has become shorter and/or more intense. The watershed-irrigated area ratio (W-I_ratio) was critical and the results showed that a slight disruption in reservoir water balance under the influence of future climate change would seriously compromise the performance of reservoirs with W-I_ratio< 5.

• Structural Engineering and Mechanics
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• 제89권6호
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• pp.617-626
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• 2024

The study investigated the behavior of plain and fibered Ultra-High Performance Concrete (UHPC) beams under varying loading conditions using integrated analysis of the flexure and acoustic emission tests. The loading rate of testing is -0.25 -2 mm/min. It is observed that on increasing loading rate, flexural strength increases, and toughness decreases. The acoustic emission testing revealed that higher loading rates accelerate crack propagation. Fiber effect and matrix cracking are identified as significant contributors to the release of acoustic emission energy, with fiber rupture/failure and matrix cracking showing rate-dependent behavior. Crack classification analysis indicated that the rise angle (RA) value decreased under quasi-static loading. The average frequency (AF) value increased with the loading rate, but this trend reversed under rate-dependent conditions. K-means analysis identified distinct clusters of crack types with unique frequency and duration characteristics at different loading rates. Furthermore, the historic index and signal strength decreased with increasing loading rate after peak capacity, while the severity index increased in the post-peak zone, indicating more severe damage. The sudden rise in the historic index and cumulative signal strength indicates the possibility of several occurrences, such as the emergence of a significant crack, shifts in cracking modes, abrupt failure, or notable fiber debonding/pull-out. Moreover, there is a distinct rise in the number of AE knees corresponding to the increase in loading rate. The crack mapping from acoustic emission testing aligned with observed failure patterns, validating its use in structural health monitoring.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제11권2호
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• pp.130-136
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• 2008

목 적: 소아 만성 B형 간염 환아들에서 라미부딘 치료의 효과와 지속성에 대해 알아보고자 하였다. 방 법: 1998년 1월부터 2008년 5월까지 서울아산병원 소아과에서 만성 B형 간염으로 진단받고 라미부딘치료를 받은 44명의 환아들의 의무기록을 후향적으로 분석하였다. 12개월 이상 추적 관찰했던 환아들을 대상으로 발병시 성별, 연령, 치료 전후의 ALT, 혈청 HBVDNA, HBeAg, anti HBe, HBsAg, anti HBs의 변화를 조사하였고, 치료의 지속성과 내성 발현에 대해 조사하였다. 결 과: 라미부딘 치료 후 3년 이내에 총 44명의 환아중 21명(48%)에서 혈청 전환이 이루어졌고, 34명(77%)에서 HBV DNA가 음전되었으며, 41명(93%)에서 혈청ALT가 정상화되었다. Kaplan-Meier법에 의한 HBeAg 누적 혈청 전환율은 3년째에 60%로 나타났다. 치료를 마친 환아 25명 중 혈청 전환된 18명의 환아 모두 약물중단 이후 최대 3년 추적 관찰시 재발 없이 지내고 있어 라미부딘 치료 반응의 지속성을 보여 주었다. 치료 중 12명(27%)에서 돌파 현상이 나타났고, 11명(25%)에서 YMDD 돌연변이가 발견되었다. 치료 전 혈청 ALT 수치는 혈청 전환을 이룬 군에서 더 높았지만, 통계적 유의성은 없었다(338${\pm}$542 IU/L vs. 144338${\pm}$163 IU/L, p> 0.05). 결 론: 만성 B형 간염 환아에서 라미부딘 치료시 절반 정도에서 치료 효과를 기대할 수 있었다. 라미부딘의 치료 반응은 장기적으로 지속되었으며, 향후 약제 내성 돌연변이의 증가에 따른 이차 약제에 대한 추가적인 연구가 필요하다고 생각된다.

• Journal of Radiation Protection and Research
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• 제22권4호
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• pp.227-235
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• 1997

병원내 방사선 작업 종사자 51명(진단방사선과 18명, 치료방사선과 17명, 핵의학과 16명)에서 림프구의 염색체이상 빈도를 대조군 49명과 비교하여 저선량 만성피폭시 인체에 미치는 영향을 조사하였다. 종사자의 축적선량은 0.30-40.07 mSv 였으며 총축적선량 5 mSv 이하가 46%로 가장 많았다. 염색체 이상이 있는 세포수는 종사자군에서 1.275%로, 대조군에서의 0.677%에 비해 더 높았다(p<0.001). 염색분체형 이상은 종사자군이 약간 높은 경향은 있지만 통계적인 유의성은 없었으며, 염색체형 이상은 대조군 $0.344{\times}10^{-2}$/cell에 비해 종사자군이 $0.706{\times}10^{-2}$/cell로 2.1배 높았다(p<0.05). 이중 교환은 대조군 $0.083{\times}10^{-2}$/cell에 비해 종사자군 $0.245{\times}10^{-2}$/cell로 3.0배 높았다(p<0.05). 총축적선량, 최근 5년 및 최근 2년간의 선량은 염색체이상과 선량-반응 관계가 없었으나, 최근 1년간 피폭선량과 염색체형 교환 빈도사이에 유의한 상관관계가 있었다(p<0.05). 근무년수와 염색체 이상빈도와 선량-반응관계는 없었으며, 각 작업부서 별 염색체이상 빈도 및 대조군과의 비교시, 염색체형 교환이 핵의학과 $0.313{\times}10^{-2}$/cell로 가장 높았으며 (p<0.05), 치료방사선과 근무자 $0.265{\times}10^{-2}$/cell (p=0.0622), 진단방사선과 근무자 $0.167{\times}10^{-2}$/cell (p=0.1107)순이었다. 색체이상이 유발될 수 있음을 확인하였으며, 따라서 림프구 염색체이상은 매우 낮은 양의 방사선 피폭에 의하여도 발생함을 알 수 있었다.