• 한국안전학회지
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• 제30권6호
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• pp.164-173
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• 2015

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, application standard differs from every industry in domestic or international for application on mythology for allocation and demonstration of SIL. Application or assessment is not easy since absence on clear criteria or common definition. This research studied not only fundamental concept of SIL required to guarantee safety in accordance with international standards for safety related equipment and system, but different types of methodologies for SIL allocation. Specifically, SIL allocation for Platform Screen Door system of railway is studied applying methodology of severity of accidents and risk graph among different methodologies for SIL allocation.

• Journal of Korean Neurosurgical Society
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• 제64권4호
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• pp.543-551
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• 2021

Objective : Hemorrhagic stroke (HS) and hypertensive retinopathy are known end organ damage of the brain and eye respectively, with HS having deleterious consequence to the patients. This study is to correlate between hypertensive retinopathy and HS in hypertensive disease. Methods : A control group of hypertensive patients only, and an investigated group of hypertensive HS patients. Fundoscopic examination to determine the grade of retinopathy was performed and then divided into low or high severity hypertensive retinopathy. Clinical and radiological parameter included are demography, vital signs, Glasgow coma scale (GCS) on admission, clot volume, site of clot, Intracerebral hemorrhage (ICH) score and Glasgow outcome scale (GOS). Data were correlated with the severity of hypertensive retinopathy. Results : Fifty patient in the control group and 51 patients in the investigated group were recruited. In the hypertensive HS group, 21 had low severity retinopathy (no or mild retinopathy) accounting for 41.2% and 30 patients had high severity (moderate or severe retinopathy). In the hypertensive patients 49 had low severity and one had high severity (p-value of 0.001). In HS group low severity showed better GCS score of 9-15 on admission (p-value of 0.003), clot volume less than 30 mL (p-value 0.001), and also a better 30 days mortality rate by using the ICH score (p-value 0.006), GOS score of 4 and 5 the low severity retinopathy fair better than the high severity retinopathy (p-value of 0.001), and the relative risk to develop HS in low severity and high severity retinopathy was 0.42 and 29.4, respectively. Conclusion : Hypertensive retinopathy screening could be used as an indicator in hypertensive patient, to evaluate the risk of developing hypertensive HS in the future.

• 해양환경안전학회지
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• 제23권3호
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• pp.217-223
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• 2017

In order to assess risk as a basic step for securing safety, it requires to select risk factors and determine the frequency and the severity of the consequence of each risk factor. This research adopted common risk factors among well-known maritime risk assessment models, and proposed objective criteria to gauge the risk level of each risk factor. The starting points of risk evolution were chosen for criteria according to related studies and seafarers' experience. The rate of risk appearance over the criteria is named as the incidence of risk factor. Therefore, the total risk level is expressed as the combination of incidence of each risk factor and severity. This quantitative method would be applied to measuring and comparing the risk level of target maritime zones, and it would also be useful to survey which risk factor be focused for reducing the total risk of a certain maritime zone.

• 한국가스학회지
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• 제13권1호
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• pp.45-51
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• 2009

본 논문은 국내에 건설된 충전소를 분석 검토하여 수소충전소에 대한 안전성 평가를 실시함으로써 수소충전 소의 안전성에 대한 확인과 충전소 설치 시 필요한 기준마련에 기초자료를 제공하는 것이 궁극적인 목표이다. 안전성 평가 방법으로 FMEA (Failure Mode and Effect Analysis)를 사용하였고, 충전소를 크게 4개의 공정(제조, 압축, 저장, 충전)으로 분류하였다. 또한 각각의 발견된 위험요소에 S (severity), O (occurrence), D (detection)의 점수를 부여하여 이 세 요소의 곱의 값인 RPN (Risk Priority Number)의 수치를 이용하여 위험의 우선순위를 정하고, 이를 바탕으로 시나리오를 생성하였다. 생성한 시나리오를 기반으로 사고피해영향평가 결과 주요한 사고 유형으로 jet fire와 폭발이 나타났고, PSA (pressure swing adsorption) 공정 feed line에서의 누출의 경우 원료물질에 따라 CO가스의 농도가 상이할 수도 있으나, CO가스중독 위험성을 함께 예측되었다.

• 한국안전학회지
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• 제33권6호
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• pp.102-114
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• 2018

The Railway Safety Management System is based on risk management and the basic purpose of risk management is safety management activities to prevent railway accidents and operational obstacles in advance. In order to manage risk, an acceptable risk standard must be established. This risk criterion is used to evaluate the railway risk with both frequency and severity. In the case of overseas railway or other industrial sectors, various factors are reflected in the main variables that constitute the occurrence frequency, but this is no the case in the domestic railway sector. In particular, the current risk assessment criteria in the railway sector remain at a level that exploits the incidents that have occurred in the past and the severity of the property damage and it dose not properly reflect complex and diverse environmental and situational changes in railway operations. Therefore, in this study, it is possible to calculate the potential occurrence of future events instead of occurrence frequency as a component of the risk assessment criteria, focusing on the High-Speed Railway. In addition to the property damage to the consequence, we suggest a rational methodology, development direction, and theoretical implications for constructing accurate and reasonable risk criteria including actual damage such as human injury and time loss.

• Steel and Composite Structures
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• 제14권4호
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• pp.367-377
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• 2013

Damage in structures often leads to failure. Thus it is very important to monitor structures for the occurrence of damage. When damage happens in a structure the consequence is a change in its modal parameters such as natural frequencies and mode shapes. Artificial Neural Networks (ANNs) are inspired by human biological neurons and have been applied for damage identification with varied success. Natural frequencies of a structure have a strong effect on damage and are applied as effective input parameters used to train the ANN in this study. The applicability of ANNs as a powerful tool for predicting the severity of damage in a model steel girder bridge is examined in this study. The data required for the ANNs which are in the form of natural frequencies were obtained from numerical modal analysis. By incorporating the training data, ANNs are capable of producing outputs in terms of damage severity using the first five natural frequencies. It has been demonstrated that an ANN trained only with natural frequency data can determine the severity of damage with a 6.8% error. The results shows that ANNs trained with numerically obtained samples have a strong potential for structural damage identification.

• 대한간호
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• 제36권4호
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• pp.88-99
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• 1997

Applying effective coping strategies and reducing powerlessness for the chronic pain adjustment of musculoskeletal patients were researched for basic data in the development of nursing intervention. The subjects were 99 musculoskeletal patients with chronic pain. Data was gathered with direct interview using a questionnaire. With the SAS tool. data were analyzed for percentage. Pearson correlation. t-test. and ANOVA according to characteristics of variables. Internal consistency(alpha) coefficients were .91 for coping scales and .71 for powerlessness scales. The results are as follows: 1. Pain duration was mainly 6 - 12 months(52. 5%). 2. Primary pain site was mainly lower limbs(58.6%) and pain severity was a moderate level. 3. The preference of coping strategies was decreased in the order named in resting. seeking social support. exercise or stretch. guarding. and asking for assistance. 4. The longer pain duration. the more the coping strategies of asking assistance used. This was stastically significant(F=3. 35. p<.05). 5. The group with the experience of hospital admission was more powerless than the group without that(F=3. as. p<.01). 6. Pain severity and powerlessness were significantly positively correlated(r=.444. p<.001). Coping strategy applying and powerlessness were significantly negatively correlated(r=-. 288. p<.01). In consequence. the nurse should playa role as the supporter of patient's maximal usage of his resources in pain relief. adjustment, and control. The nurses should also develop for the nursing intervention of physical therapy and educational programs.

• Child Health Nursing Research
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• 제10권1호
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• pp.117-125
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• 2004

Purpose: The research was conducted to investigate the experience of maternal role attainment of mothers of premature infants admitted in NICU and to conceptualize the phenomena. Method: The grounded theory method was utilized for data collection and analysis. 8 mothers of premature infants were selected and in-depth interview was performed. Paradigm model was utilized for data analysis and presentation. Result: The central category was 'unstable maternal identity'. The properties of the core phenomena was 'ambivalent feeling to baby' 'negative emotion' 'commitment to baby'. The loss of control due to premature delivery was the causal condition. contextual condition was the 'perceived threats' due to severity of the premature infant and uncerainty of the baby's life. The mother's health status, economic status, and familial and social support was recognized as intervening conditions during the process of maternal role attainment. The strategic action/interactions were emotion-focused coping, reappraisal of the situation, problem-focused coping, and information seeking. The consequence was the maternal role attainment with competence and expectation. Conclusion: The process of maternal role attainment was affected by threats due to severity of the baby and intervening factors and interaction strategy. Further research is recommended to develop adequate intervention method during the process of maternal role attainment.

• 대한간호학회지
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• 제52권3호
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• pp.308-323
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• 2022

Purpose: This study aimed to construct and test a predictive model for the quality of life (QOL) in mothers of children with developmental disabilities (DB). The hypothesized model included severity of illness, distress, uncertainty, self-help, and parenting efficacy as influencing factors, QOL as a consequence based on the Braden's Self-Help Model. Methods: The data were collected through a direct and online surveys from 206 mothers in 8 locations, including welfare or daycare centers, developmental treatment centers, and The Parents' Coalition for the Disabled located in two provinces of Korea. Data were analysed using SPSS/WIN 23.0 and AMOS 21.0 program. Results: The fit indices of the predictive model satisfied recommended levels; 𝛘² = 165.79 (p < .001), normed 𝛘² (𝛘²/df) = 2.44, RMR = .04, RMSEA = .08, GFI = .90, AGFI = .85, NFI = .91, TLI = .93, CFI = .95. Among the variables, distress (β = - .46, p < .001), parenting efficacy (β = .22, p < .001), and self-help (β = .17, p = .018) had direct effects on QOL. Severity of illness (β = - .61, p = .010) and uncertainty (β = - .08, p = .014) showed indirect effects. The explanatory power of variables was 61.0%. Conclusion: The study results confirm the utility of Braden's Self-Help Model. They provide a theoretical basis for improving QOL in mothers of children with DB. Nursing intervention strategies that can relieve mothers' distress and uncertainty related to disease and enhance parenting efficacy and self-help behavior should be considered.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.178-178
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• 2023

Drought and flooding have historically coexisted in Korea, occurring at different times and with varying cycles and trends. The drought indicators measured were (PDSI), (SPI), and (SPEI) in order to statistically analyze the annual or periodic drought occurrence and objectively evaluate statistical characteristics such as the periodicity, tendency, and frequency of occurrence of droughts in the Doam watershed. To compute potential evapotranspiration (PET), both Thornthwaite (Thor) and Penman-Monteith (PM) parameterizations were considered, and the differences between the two PET estimators were analyzed. Hence, SPIs 3 and SPIs 6 revealed a tendency to worsen drought in the spring and winter and a tendency to alleviate drought in the summer in the study area. The seasonal variability trend did not occur in the SPIs 12 and PDSI, as it did in the drought index over a short period. As a result of the drought trend study, the drought from winter to spring gets more severe, in addition to the duration of the drought, although the periodicity of the recurrence of the drought ranged from 3 years to 6 years at the longest, indicating that SPIs 3 showed a brief time of around 1 year. SPIs 6 and SPIs 12 had a term of 4 to 6 years, and PDSI had a period of roughly 6 years. Based on the indicators of the PDSI, SPI, and SPEI, the drought severity increases under climate change conditions with the decrease in precipitation and increased water demand as a consequence of the temperature increase. Therefore, our findings show that national and practical measures are needed for both winter and spring droughts, which happen every year, as well as large-scale and extreme droughts, which happen every six years.