• 한국항해항만학회지
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• 제47권2호
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• pp.93-99
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• 2023

This study aimed to determine relationships among risk factors influencing container port operation using Bayesian network. Risk factors identified from prior studies were classified into five groups: human error, machinery error, environmental risk, security risk, and natural disasters. P anel experts discussed identified risk factors to fulfil conditional probability tables of the interdependence model. The interdependence model was also validated by sensitivity analysis and provided an interrelation of factors influencing the direction of each other. Results of the interdependence model were partially in line with results from prior studies while practices in the global port industry confirmed interrelationships of risk factors. In addition, the relationship between top-ranked risk factors can provide a schematic drawing of the model. Accordingly, results of this study can expand the prior research in the Korean port industry, which may help port authorities improve risk management and reduce losses from the risk.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.353-361
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• 2018

본 연구의 목적은 공군 장병들의 거부민감성이 우울 및 불안에 영향을 미치는지 알아보고 이러한 관계에서 과거 중 고등학교 시절 학교 폭력 피해 경험이 조절 효과를 보이는지 알아보는 것이다. 또한 이러한 연구 결과를 토대로 군 장병들의 군 생활 적응에 있어 위험 요소들을 찾고 이들의 심리적 적응을 향상시키는 방안을 제시하고자 한다. 이를 위해 S시에 소재하는 공군 장병 126명을 대상으로 거부민감성, 우울, 불안, 학교 폭력 피해 경험을 측정하는 설문지를 실시하였다. 조절효과를 검증하기 위해 거부민감성, 학교 폭력 피해 경험, 이들 간의 상호 작용 항을 투입하여 위계적 회귀분석을 실시하였다. 연구 결과, 거부민감성과 우울의 관계에서 학교폭력 피해 경험의 조절 효과는 유의미하였으며, 거부민감성과 불안의 관계에서 학교 폭력 피해 경험의 조절 효과도 역시 유의미하였다. 이를 통해 학교 폭력 피해 경험은 거부민감성이 우울 및 불안에 미치는 영향을 증가시킴을 알 수 있었다. 이들의 상호작용 패턴에 대해 단순 주효과 기울기 분석을 통해 확인하였다. 마지막으로 연구 결과를 통해 학교폭력피해 경험이 군생활 적응의 고위험 요소이며 이들을 위한 상담적 개입의 중요성 등에 대해 논의하였다.

• 한국치위생학회지
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• 제20권3호
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• pp.303-312
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• 2020

Objectives: The purpose of this study was to investigate the relationship between periodontal disease, number of remaining teeth with high-sensitivity C-Reactive protein in Korean adults aged 40 and older. Methods: The study used the Sixth Korea National Health and Nutrition Examination Survey (KNHANES VI-3), 2015. The study sample consisted of 3,883 aged 40 years or older who had completed the health survey and the health examination. Logistic regression analyses were performed to examine the odds ratios of high-sensitivity C-Reactive protein by periodontal disease and number of remaining teeth, adjusting for demographic characteristics, chronic diseases and oral health behavior-related variables. Results: When the demographic and chronic diseases were adjusted, the risk of high-sensitivity C-Reactive protein (hs-CRP) average 1.23 mg/L or higher was 1.36 times higher in patients with periodontal disease between the ages of 40 and 49, but it was not significant (OR=1.36; 95% CI=0.82-2.23). In addition, in the group of 0~23 remaining teeth aged 40~49 years, the risk of higher than the average 1.23 mg/L of high-sensitivity C-Reactive protein was 2.03 times higher (OR=2.03; 95% CI=1.10-3.74), and 1.49 times higher in 60~69 years (OR=1.07; 95% CI=1.04-2.76). Conclusions: This study found that periodontal disease and tooth loss in Korean adults aged 40 and older was significantly associated with high-sensitivity C-reactive protein.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2929-2932
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• 2014

Purpose: To evaluate the diagnostic performances of risk of malignancy index (RMI), CA-125 and ultrasound score in differentiating between benign and borderline or malignant ovarian tumors and find the best diagnostic test for referral of suspected malignant ovarian cases to gynaecologic oncologists. Materials and Methods: This prospective study covered 467 women with pelvic tumors scheduled for surgery at our hospital between July 2011 and July 2013. The RMI was obtained from ultrasound score, CA125 and menopausal status. The diagnostic values of each parameter and the RMI were determined and compared using Statistical Packages for Social Sciences Version 14.0.1. Results: In our study, 61% of ovarian tumors were malignant in the post-menopausal age group. RMI with a cut-off 150 had sensitivity of 84% and specificity of 97% in detecting ovarian cancer. CA-125>30 had a sensitivity of 84% and a specificity of 83%. An ultrasound score more than 2 had a sensitivity of 96% and specificity of 81%. RMI had the least false malignant cases thus avoiding unnecessary laparotomies. Ultrasound when used individually had the best sensitivity but poor specificity. Conclusions: Our study has demonstrated the RMI to be an easy, simple and applicable method in the primary evaluation of patients with pelvic masses. It can be used to refer suspected malignant patients to be operated by a gynaecologic oncologist. Other models of preoperative evaluation should be developed to improve the detection of early stage invasive, borderline and non-epithelial ovarian cancers.

• 한국항해항만학회지
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• 제43권5호
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• pp.310-319
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• 2019

With the recent increase in the volume of liquid cargo transportation, there is a need for STS( Ship To Ship) globally. In the case of the STS mooring, the safety assessment should be conducted according to other criteria because mooring is different from the general mooring at the quay, but there is no separate standard in Korea. Thus in this study, STS mooring simulation and sensitivity analysis using OPTIMOOR program, the numerical analysis program, was conducted to identify the characteristics of the STS mooring. The target sea modeled the Yeosu port anchorage in Korea and the target ship was selected as the case of VLCC (Very Large Crude Oil Carrier)-VLCC. Through the numerical simulation and sensitivity analysis, the characteristics of STS mooring were identified. Also based on these results, we focused on establishing the standard for STS mooring safety assessment. Numerical simulation results show that the STS mooring safety can be changed according to a ship's cargo loading condition, pre-tension of mooring line, sea depth, encounter angle with the weather, and the weather condition. Additionally, the risk matrix is prepared to establish the safe external force range in the corresponding sea area. This result can be used to understand the mooring characteristics of STS and contribute to the revision of mooring safety assessment criteria.

• 한국임상수의학회지
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• 제31권1호
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• pp.40-45
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• 2014

Abalone herpes-like virus (AbHV) is a fatal disease of abalones that impose severe economic impacts on the industry of infected regions due to high mortality. The aim of this study was to quantify the risk of introducing AbHV into Korea through the importation of live abalones for human consumption by import risk analysis (IRA). Monte Carlo simulation models were developed to provide estimates of the probability that a ton of imported abalone contains at least one AbHV-infected individual, using historical trade data and relevant literatures. A sensitivity analysis with 5,000 iterations was also conducted to determine the extent to which input parameters affect the outcome of the model. Although many uncertainties were present in the data, the results indicated that, if 5,000 tons of abalone were imported from a hypothetical exporting country with low prevalence of AbHV (model 1), there would be at least one AbHV-infected abalones in 4,816 of those tons (96.3%), while there would be at least one AbHV-infected abalones in 100% of those tons imported from country with high prevalence (model 2). Sensitivity analysis indicated that for model 1, prevalence was the strongest influence factor on the predicted number of infections. For model 2, background mortality and washing to reduce the risk of surface contamination during processing were the major contributing factors. Risk management strategies need to be enforced to reduce the risk of AbHV introduction in that at least one infected abalone would remain in a consignment from country even with a low prevalence of AbHV infection. The methodology and the results presented here will contribute to improve the development of AbHV management program, and with more accurate data this IRA model will aid science-based decision-making on mitigation strategies to reduce the risk of AbHV introduction in Korea.

• 한국전문물리치료학회지
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• 제30권2호
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• pp.102-109
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• 2023

Background: While efforts have been made to differentiate fall risk in older adults using wearable devices and clinical methodologies, technologies are still infancy. We applied a decision tree (DT) algorithm using inertial measurement unit (IMU) sensor data and clinical measurements to generate high performance classification models of fall risk of older adults. Objects: This study aims to develop a classification model of fall risk using IMU data and clinical measurements in older adults. Methods: Twenty-six older adults were assessed and categorized into high and low fall risk groups. IMU sensor data were obtained while walking from each group, and features were extracted to be used for a DT algorithm with the Gini index (DT1) and the Entropy index (DT2), which generated classification models to differentiate high and low fall risk groups. Model's performance was compared and presented with accuracy, sensitivity, and specificity. Results: Accuracy, sensitivity and specificity were 77.8%, 80.0%, and 66.7%, respectively, for DT1; and 72.2%, 91.7%, and 33.3%, respectively, for DT2. Conclusion: Our results suggest that the fall risk classification using IMU sensor data obtained during gait has potentials to be developed for practical use. Different machine learning techniques involving larger data set should be warranted for future research and development.

• 대한토목학회논문집
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• 제33권5호
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• pp.1753-1763
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• 2013

본해상교량 프로젝트의 설계단계에서 선박충돌 문제는 주로 교량 하부구조의 단면 결정에 관여하게 되며, 위험도 평가와 충돌 시뮬레이션 등을 통해 설계를 수행하게 된다. 선박의 충돌위험은 다양한 확률모델에 의해 평가되며 대체로 AASHTO Guide(2009)의 Method II와 유사하다. 그러나 해당기준에서 사용되는 일부 요소는 내륙수로에 국한되어 있거나 지역적인 요인이 강하여 설계자의 판단이 요구되므로 관련 기준이나 연구결과 등을 참고하여 결정해야 한다. 본 연구에서는 2010년 선박운항데이터를 사용하여 인천대교에 대한 위험도평가를 수행하고 기존 하부구조 및 방호구조물에 대한 위험도 및 내충돌 성능을 검토하였다. 그리고 AASHTO Guide의 Method II를 기준으로 하여 위험도평가에 필요한 요소들의 추정 방법과 적용 사례, 관련 연구결과에 대한 고찰을 수행하였다. 이로부터 위험도평가에 필요한 요소들의 적절한 가변영역을 정의하고 해당 구간에 대한 민감도 분석을 수행하였으며 설계단계에서 설계자가 주의하여 적용해야 하거나 지역적인 데이터의 직접 분석이 필요한 요소들이 확인되었다. 이번 연구는 해상교량에 대한 선박충돌을 고려한 설계시 위험도 분석과 관련하여 기본적인 참고자료가 될 것으로 판단된다.

• 대한간호학회지
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• 제44권6호
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• pp.595-607
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• 2014

Purpose: The Braden Scale is one of the most intensively studied risk assessment scales used in identifying the risk of developing pressure sore. However, not all studies show that the predictive validity of this scale is sufficient. The purpose of this study was to evaluate the Braden Scale for predicting pressure ulcer development. Methods: Articles published 1946 and 2013 from periodicals indexed in Ovid Medline, Embase, CINAHL, KoreaMed, NDSL and other databases were selected, using the following keywords: 'pressure ulcer'. The QUADAS-II was applied to assess the internal validity of the diagnostic studies. Selected studies were analyzed using meta-analysis with MetaDisc 1.4. Results: Thirty-eight diagnostic studies with high methodological quality, involving 17,934 patients, were included. Results of the meta-analysis showed that the pooled sensitivity and specificity of the Braden Scale were 0.74 (95% CI: 0.72-0.76), 0.75 (95% CI: 0.74-0.76) respectively. However the predictive validity of the Braden Scale has limitation because there was high heterogeneity between studies. Conclusion: The Braden Scale's predictive validity of risk for pressure ulcer is interpreted as at a moderate level. However there is a limitation to the interpretation of the results, because of high heterogeneity among the studies.

• Nuclear Engineering and Technology
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• 제52권4호
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• pp.764-775
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• 2020

Periodic safety reviews (PSRs) are conducted on operating nuclear power plants (NPPs) and have been mandated also for research reactors in Korea, in response to the Fukushima accident. One safety review tool, the probabilistic safety assessment (PSA), aims to identify weaknesses in the design and operation of the research reactor, and to evaluate and compare possible safety improvements. However, the PSA for research reactors is difficult due to scarce data availability. An important element in the analysis of research reactors is the reactor protection system (RPS), with its functionality and importance. In this view, we consider that of the AGN-201K, a zero-power reactor without forced decay heat removal systems, to demonstrate a risk-informed safety improvement study. By incorporating risk- and safety-significance importance measures, and sensitivity and uncertainty analyses, the proposed method identifies critical components in the RPS reliability model, systematically proposes potential safety improvements and ranks them to assist in the decision-making process.