• Nuclear Engineering and Technology
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• 제55권3호
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• pp.981-988
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• 2023

A seismic event caused an accident at the Fukushima Nuclear Power Plant, which further resulted in simultaneous accidents at several units. Consequently, this incident has aroused great interest in the safety of nuclear power plants worldwide. A reasonable safety evaluation of such an external event should appropriately consider the correlation between SSCs (structures, systems, and components) and the probability of failure. However, a probabilistic safety assessment in current nuclear industries is performed conservatively, assuming that the failure correlation between SSCs is independent or completely dependent. This is an extreme assumption; a reasonable risk can be calculated, or risk-based decision-making can be conducted only when the appropriate failure correlation between SSCs is considered. Thus, this study analyzed the effect of the failure correlation of SSCs on the safety of the system to realize rational safety assessment and decision-making. Consequently, the impact on the system differs according to the size of the failure probability of the SSCs and the AND and OR conditions.

• 중환자간호학회지
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• 제14권3호
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• pp.141-156
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• 2021

Purpose : This study aimed to systematically review the preventive interventions for delirium in Korean intensive care unit (ICU) patients and evaluate their efficacy. Methods : For this systematic review and meta-analysis, we searched the literature and selected studies from data sources that included the RISS, KISS, National Central Library, National Assembly Library, DBpia, Science on, MEDLINE, and Cochrane Library. We used Cochrane's revised tool for risk of bias in randomized trials and non-randomized studies of intervention tools to assess the quality of the selected studies. The effect size of the intervention was calculated as odds ratio (OR) and standardized mean difference (SMD). Results : Preventive interventions reported in 23 studies with a total of 4,799 ICU patients were effective in reducing the occurrence of delirium (OR=0.64, 95% CI : 0.49~0.91, p=.011), but not the duration (SMD=-0.22, 95% CI : -0.51~0.08, p=.148). As a result of a subgroup analysis, non-pharmacological interventions were effective in reducing the occurrence of delirium (OR=0.66, 95% CI : 0.47~0.94, p=.020), while pharmacological interventions had no effect (OR=0.68, 95% CI : 0.33~1.40, p=.295). Among the non-pharmacological interventions, multi-component intervention had the largest effect size (OR=0.38, 95% CI : 0.26~0.55, p<.001). Conclusion : Non-pharmacological interventions were effective in reducing the occurrence of delirium. We recommend the development and application of multi-component interventions to prevent delirium in the Korean ICU patients.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1428-1432
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• 2007

One of the most important targets of transportation is to transport human and commodities to the destination safely. Railway has low risk, compared with land, ocean and flight route and it assures high security as well as high speed driving, since it runs on regular track. However, train accident may result in tragic accident due to small carelessness, so special event recorder is preferably used in order for clarity of responsibility in case of accident, maintenance of signal device and defect analysis. JRU(Juridical Recorder Unit) for ATC/ATS/ATP can be more advanced event recorder. Event recorder of KTX-I which is running now is installed one by one on each leading car and last car, and operation plan of event recorder in case of single trainset is suggested. But regarding train operation of multi-coupled trainset operation such as KTX-II, more detailed study is required for event recorder revitalization and record data process method. Therefore, this research aims at operation plan used in existing event recorder, and suggests effective operation and management plan of event recorder in multi-coupled trainset such as new High Speed Train.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.303-303
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• 2017

Japanese agriculture has faced to several threats: aging and decrease of farmer population, global competition, and the risk of climate change as well as harsh and variable weather. On the other hands, the number of large scale farms is increasing, because farm lands have been being aggregated to fewer numbers of farms. Cost cutting, development of efficient ways to manage complicatedly scattered farm lands, maintaining yield and quality under variable weather conditions, are required to adapt to changing environments. Information and communications technology (ICT) would contribute to solve such problems and to create innovative technologies. Thus we have been developing an early warning and decision support system to reduce weather and climate risks for rice, wheat and soybean production in Japan. The concept and prototype of the system will be shown. The system consists of a weather data system (Agro-Meteorological Grid Square Data System, AMGSDS), decision support contents where information is automatically created by crop models and delivers information to users via internet. AMGSDS combines JMA's Automated Meteorological Data Acquisition System (AMeDAS) data, numerical weather forecast data and normal values, for all of Japan with about 1km Grid Square throughout years. Our climate-smart system provides information on the prediction of crop phenology, created with weather forecast data and crop phenology models, as an important function. The system also makes recommendations for crop management, such as nitrogen-topdressing, suitable harvest time, water control, pesticide spray. We are also developing methods to perform risk analysis on weather-related damage to crop production. For example, we have developed an algorism to determine the best transplanting date in rice under a given environment, using the results of multi-year simulation, in order to answer the question "when is the best transplanting date to minimize yield loss, to avoid low temperature damage and to avoid high temperature damage?".

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1453-1461
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• 2016

Regarding 'mate' intake (infusion of Ilex paraguariensis herb, a staple beverage in temperate South American regions), most epidemiologic studies showed positive associations with risk of some cancers, (e.g. upper aerodigestive tract), but evidence on breast cancer (BC) risk is limited to a previous multi-site study, which reported a non significant odds ratio [OR]=0.85, 95% confidence interval [95% CI] 0.67-1.09, p for trend=0.31) for the highest quartile of intake. The present study was conducted in order to further assess associations of 'mate' intake with BC risk. We combined two databases of women belonging to public and private healthcare hospitals. The sample included 572 BC incident cases and 889 controls interviewed with a specific questionnaire featured by socio-demographic, reproductive and lifestyle variables, and a food frequency questionnaire of 64 items, also analyzing 'mate' intake (consumer status, daily intake, age at start, age at quit, duration of habit, intensity of intake). ORs and their 95%CI were calculated through unconditional logistic regression, adjusting for relevant potential confounders. The highest quartile of 'mate' intake was inversely associated with BC risk (OR=0.40, 95%CI 0.26-0.57, p for trend <0.001). Stratified analyses also displayed strong significant inverse associations for 'mate' in frequent tea drinkers (OR=0.22), high energy intake (OR=0.23), high body mass index (OR=0.29) and in postmenopausal women (OR=0.36), among other results. As conclusions, we found evidence of a significant inverse association for 'mate' intake and BC risk.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1297-1306
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• 2019

Probabilistic safety assessments (PSA) have been used for several decades to visualize the risk level of commercial nuclear power plants (NPPs). Since the role of a human reliability analysis (HRA) is to provide human error probabilities for safety critical tasks to support PSA, PSA quality is strongly affected by HRA quality. Therefore, it is important to understand the underlying limitations or problems of HRA techniques. For this reason, this study conducted a survey among 14 subject matter experts who represent the HRA community of domestic Korean NPPs. As a result, five significant HRA issues were identified: (1) providing a technical basis for the K-HRA (Korean HRA) method, and developing dedicated HRA methods applicable to (2) diverse external events to support Level 1 PSA, (3) digital environments, (4) mobile equipment, and (5) severe accident management guideline tasks to support Level 2 PSA. In addition, an HRA method to support multi-unit PSA was emphasized because it plays an important role in the evaluation of site risk, which is one of the hottest current issues. It is believed that creating such a catalog of prioritized issues will be a good indication of research direction to improve HRA and therefore PSA quality.

• 한국대기환경학회지
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• 제8권4호
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• pp.247-256
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• 1992

Airborne suspended particulates were collected at Shinchon by a high volume cascade impactor from Sep. 1990 to Aug. 1991. Organic matter was extracted from particulates and fractionated by liquid-liquid extraction and thin layer chromatography. Substances in the PAHs and nitroarenes'subfraction of neutral fraction were determined by capillary gas chromatography. Based on unit risk estimates by multi-stage model of benzo[a]pyrene and the results of exposure estimates, cancer risk was assessed. The annual average concentration of total suspended particulates was 201.77g/$m^3$. The percentage of fine particulates was 57.40. The concentration of total suspended particulates showed seasonal variations and was high in winter and spring. The average concentration of extractable organic matter was 8.12g/$m^3$. In all, 21 PAHs were identified and quantified. The annual concentration of fluoranthene was 2.38ng/$m^3$, and that was the highest value of all PAHs. A carcinogenic compound, benzo[a]pyrene, was at a concentration of 1.84ng/$m^3$. All the 10 nitroarenes were also identified and quantified. The major nitroarene in the Shinchon area was 2,7-dinitrofluorene. The annual concentration of 1-nitropyrene was 1.56ng/$m^3$. Concentrations of PAHs and nitroarenes were high in winter and low in summer. The life time excess risk estimates of benzo[a]pyrene was calculated as 0.96 persons/a million population in this experiment. In the rank of relative potenties, carcinogenic effects of the other PAHs were calculated as 0.004-0.108 persons/a million population.

• 터널과지하공간
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• 제32권6호
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• pp.451-463
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• 2022

수직갱도에서 붕괴사고가 일어났을 때, 붕괴현장의 위험도를 신속하게 평가하는 것은 매우 중요하다. 사고현장에서 추가적인 붕괴 위험 때문에 인력을 투입한 직접적인 조사는 불가능하다. 수백 미터 심도를 갖는 수직갱도에서는 무선 신호의 한계와 와류 때문에 고속 라이다 센서를 장착한 드론을 이용한 조사가 불가능하다. 기존 연구에서는 견인방식을 이용한 단일채널 Lidar 센서를 3차원 형상화 장비가 구현되어 적용되었다. 관성(IMU)센서 데이터를 바탕으로 탐사시 발생하는 회전 운동과 진자운동에 대한 보정이 이루어졌고, 인접 측정데이터 간의 유사성 검토를 통해 정밀 보정을 수행하였으나 탐사 깊이가 깊어질수록 오차가 누적되는 현상이 발견되었다(Kim et al.(2020)). 본 논문에서는 다중채널 Lidar 센서를 적용하여 견인장치에 의해 상승이동하면서 연속적인 단면데이터가 수집되었다. 다중채널 Lidar의 방사 특성 때문에 발생하는 데이터 중첩성을 이용하여 동일 심도의 측정데이터 간의 유사성을 통해 회전운동을 정밀 보정하기 위한 기법이 적용되었다. 180 m 심도의 수직갱도에서 구현된 탐사장비를 이용하여 0~165 m 구간이 조사하여 수직갱도의 형상이 3차원 그래픽으로 재구성되었다.

• 한국산학기술학회논문지
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• 제18권10호
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• pp.785-793
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• 2017

미사강변도시 단독주택지에 적용되는 지구단위계획지침이 지역의 특성을 고려하지 않은 부분과 기존의 자치조례에 준하고 있어 이로 인하여 단독주택지의 환경을 악화시키고 있는 것으로 조사되었다. 조사결과 1)미사강변도시의 경우 지역 내의 공동주택(아파트)에 대한 디자인 가이드라인은 디테일하게 규정하고 있는 반면에 단독주택지의 주택건축에 대한 디자인 가이드라인이 계획되어 있지 않다. 2)공동주택과 다가구주택에 대한 주차대수 산정에 대한 형평성과 다가구주택이 단독주택으로 분류됨에 따른 주차장 법규의 미비로 인한 문제로 주거환경이 악화되고 있다. 3)지구단위계획지침에 따라 1층 근생의 외벽재료를 유리로 규정하고 있고 협소한 주차공간으로 유리외벽에 인접하여 주차하는 경우 위험성에 대한 대비가 필요하다. 4)초등학교, 유치원이 위치하고 있음에도 불구하고 주차부족 등 차량의 혼잡도가 높아 통학 학생들에게 많은 위험성이 있다. 5)주차장 넓이를 고려하지 않은 가구계획과, 지역의 특성을 고려하지 않은 주차장법 적용으로 여러 문제점이 발생하고 있다. 6)보행자 전용도로가 보행자의 동선을 고려하지 않고 계획되어 타용도로 전용되고 있다.

• 아동학회지
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• 제30권6호
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• pp.1-14
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• 2009

Korean families have been undergone tremendous changes during the past three decades with societal changes. Korean families become smaller, diverse, and multi-cultural. These family changes challenge child development research. Family is not just an intimate relationship. Family is also a structural environment, a system linking micro and macro system, an institution, and an ideology. Consequently, researchers need to pay attention to various ways family influence child development and take into account family as a whole unit. Researchers are also challenged to make a stance regarding family changes and diversity. Temporality is another important issue in studying how family development and child development interact. In terms of public policy, social services should be developed to cope with the new social risks from family changes and to mitigate a growing developmental gap among the children of families with different economic classes.