• Journal of Chest Surgery
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• 제55권6호
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• pp.452-461
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• 2022

Background: Extracorporeal membrane oxygenation (ECMO) can be used in patients with refractory cardiogenic shock or respiratory failure. In South Korea, the need for transporting ECMO patients is increasing. Nonetheless, information on urgent transportation and its outcomes is scant. Methods: In this retrospective review of 5 years of experience in ECMO transportation at a single center, the clinical outcomes of transported patients were compared with those of in-hospital patients. The effects of transportation and the relationship between insertion-departure time and survival were also analyzed. Results: There were 323 cases of in-hospital ECMO (in-hospital group) and 29 cases transferred to Hallym University Sacred Heart Hospital without adverse events (mobile group). The median transportation time was 95 minutes (interquartile range [IQR], 36.5-119.5 minutes), whereas the median transportation distance was 115 km (IQR, 15-115 km). Transportation itself was not an independent risk factor for 28-day mortality (odds ratio [OR], 0.818; IQR, 0.381-1.755; p=0.605), long-term mortality (OR, 1.099; IQR, 0.680-1.777; p=0.700), and failure of ECMO weaning (OR, 1.003; IQR, 0.467-2.152; p=0.995) or survival to discharge (OR, 0.732; IQR, 0.337-1.586; p=0.429). After adjustment for covariates, no significant difference in the ECMO insertion-departure time was found between the survival and mortality groups (p=0.435). Conclusion: The outcomes of urgent transportation, with active involvement of the ECMO center before ECMO insertion and adherence to the transport protocol, were comparable to those of in-hospital ECMO patients.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.15-19
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• 2022

The radial distribution systems (RDS) commonly used around the world has the following disadvantages. First, when the DL is operated on a radial system, the line utilization rate is usually kept low. Second, if a fault occurs in the radial DL, a power outage of 3 to 5 minutes is occurring depending on the operator's proficiency and fault situation until the fault section is separated and the normal section is replaced. To solve this problem, Various methods have been proposed at domestic and foreign to solve this problem, and in Korea, research is underway on the advanced system of operating multiple linked DL always. A system that is electrically linked always, and that is built to enable high-speed communication during the protection coordination is named networked distribution system (NDS). Because the load shares the DL, the line utilization rate can be improved, and even if the line faults, the normal section does not need to be cut off, so the normal section does not experience a power outage. However, since it is impossible to predict in which direction the fault current will flow when a failure occurs in the NDS, a communication-based protection coordination is used, but there is no backup protection coordination method in case of communication failure. Therefore, in this paper, we propose a protective cooperation method to apply as a backup method when communication fails in NDS. The new method is to change TCC by location of CB using voltage drop in case of fault.

• Geomechanics and Engineering
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• 제33권5호
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• pp.477-486
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• 2023

In the studies on fault dislocation of tunnel, existing literatures are mainly focused on the problems caused by normal and reverse faults, but few on strike-slip faults. The paper aims to research the deformation and failure mechanism of a tunnel under strike-slip faulting based on a model test and test-calibrated numerical simulation. A potential faulting hazard condition is considered for a real water tunnel in central Yunnan, China. Based on the faulting hazard to tunnel, laboratory model tests were conducted with a test apparatus that specially designed for strike-slip faults. Then, to verify the results obtained from the model test, a finite element model was built. By comparison, the numerical results agree with tested ones well. The results indicated that most of the shear deformation and damage would appear within fault fracture zone. The tunnel exhibited a horizontal S-shaped deformation profile under strike-slip faulting. The side walls of the tunnel mainly experience tension and compression strain state, while the roof and floor of the tunnel would be in a shear state. Circular cracks on tunnel near fault fracture zone were more significant owing to shear effects of strike-slip faulting, while the longitudinal cracks occurred at the hanging wall.

• 중환자간호학회지
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• 제16권2호
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• pp.15-27
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• 2023

Purpose : This study aimed to examine the relationship between sleep quality and its influencing factors in patients with coronary artery disease (CAD). Methods : This descriptive correlational study included 130 patients with CAD admitted to the cardiology department of a general hospital in B City between September 2019 and February 2020. Data were collected using structured questionnaires and research instruments to measure sleep quality, anxiety, depression, chronotype, and daytime sleepiness. Results : The mean scores for sleep quality, daytime sleepiness, anxiety, and depression were 7.59±3.45, 6.45±3.46, 6.58±3.88, and 7.74±4.05, respectively. In terms of chronotypes, 10.8%, 48.5%, and 40.7% of the participants had evening-, intermediate-, and morning-type patterns, respectively. Sleep quality was significantly correlated with anxiety (r=0.38, p<.001), depression (r=.37, p<.001), and daytime sleepiness (r=.26, p =.002). Factors associated with sleep quality in patients with CAD included anxiety (β=.29), heart failure (β=.22), daytime sleepiness(β=.21), and sleeping alone (β=.19). Collectively, these factors had an explanatory power of 23.1% for sleep quality variance. Conclusion: Patients with CAD often experience poor sleep quality owing to various factors such as anxiety, daytime sleepiness, heart failure, and sleeping alone. It is recommended that healthcare providers objectively evaluate sleep and identify factors that influence sleep quality. This will enable the development of effective methods for sleep management as part of nursing care.

• 대한토목학회논문집
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• 제26권1A호
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• pp.219-228
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• 2006

경량콘크리트는 보통콘크리트에 비해 가볍다는 장점 때문에 자중의 영향을 많이 받는 장지간 교량과 고층건물에 자주 적용되고 있다. 국내에서는 고층건물에 적용된 예는 있으나 교량에 적용된 실적은 없는 상태이다. 본 연구에서는 고강도 경량 콘크리트의 펀칭전단강도에 대한 실험적 연구를 수행하였으며, 그 결과를 나타내었다. 이를 위하여 고강도 경량콘크리트와 보통콘크리트를 이용한 단순판을 각각 2개씩 제작하였으며, 단순판의 중앙부에 정적하중을 파괴시까지 재하하였다. 경량콘크리트의 압축강도는 47 MPa이며 보통콘크리트의 압축강도는 32 MPa이다. 실험결과 모든 실험체는 펀칭전단으로 파괴되었으며, 파괴시까지 고강도 경량콘크리트를 사용한 단순판의 거동은 일반 콘크리트를 사용한 바닥판과 유사한 거동 특성을 나타내었다. 실험결과를 토대로 고강도 경량콘크리트를 교량바닥판에 적용시 바닥판의 안전성 및 사용성을 분석하였다.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4367-4381
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• 2023

Nuclear power plants are increasingly being equipped with digital I&C systems. Although some probabilistic safety assessment (PSA) models for the digital I&C of nuclear power plants have been constructed, there is currently no specific internationally agreed guidance for their modeling. This paper presents an initiative by the OECD Nuclear Energy Agency called "Digital I&C PSA - Comparative application of DIGital I&C Modelling Approaches for PSA (DIGMAP)", which aimed to advance the field towards practical and defendable modeling principles. The task, carried out in 2017-2021, used a simplified description of a plant focusing on the digital I&C systems important to safety, for which the participating organizations independently developed their own PSA models. Through comparison of the PSA models, sensitivity analyses as well as observations throughout the whole activity, both qualitative and quantitative lessons were learned. These include insights on failure behavior of digital I&C systems, experience from models with different levels of abstraction, benefits from benchmarking as well as major contributors to the core damage frequency and those with minor effect. The study also highlighted the challenges with modeling of large common cause component groups and the difficulties associated with estimation of key software and common cause failure parameters.

• 한국간담췌외과학회지
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• 제26권1호
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• pp.69-75
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• 2022

Backgrounds/Aims: Progressive familial intrahepatic cholestasis (PFIC) is an autosomal recessive inherited disease requiring liver transplantation (LT). The objective of this study was to investigate the clinicopathological features and posttransplant courses of seven LT recipients with PFIC. Methods: This was a retrospective single-center study of patients with PFIC who underwent LT from January 2013 to June 2020. Results: Two and five patients were diagnosed with PFIC type 1 and type 2, respectively. For all seven patients, age of PFIC onset was at birth. Jaundice was present in all cases. Mean pretransplant total and direct bilirubin levels were 16.1 ± 8.1 mg/dL and 12.4 ± 6.2 mg/dL, respectively. Median patient age and body weight at LT were 10 months and 7 kg, respectively. Types of donors were mothers of patients in four and deceased donors in three. All five patients with PFIC type 2 recovered uneventfully. One patient each with PFIC type 1 underwent retransplantation due to graft failure or died due to multi-organ failure. Overall graft and patient survival rates at five years were 66.7% and 83.3%, respectively. Bile salt export pump immunohistochemical staining showed normal canalicular expression in two patients with PFIC type 1, focal loss in two patients with PFIC type 2, and total loss in three patients with PFIC type 2. Conclusions: LT is currently the only effective treatment for PFIC-associated end-stage liver diseases. It is mandatory to perform regular follow-up due to the risk of complications including steatohepatitis, especially for patients with PFIC type 1.

• 아동학회지
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• 제38권1호
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• pp.185-203
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• 2017

Objective: The present study examined the perspectives of grandparents raising their grandchildren in an attempt to better understand grandparents' child-rearing experience while providing kinship foster care to their primary-grade grandchildren. Methods: Data were collected through individual in-depth interviews with eight grandparents who have raised one or two primary-grade (ages 8-10) grandchildren using a qualitative approach. Results: First, the participants viewed the reason for their kinship foster care as a failure for caring for their own children and accepted the present grandparent-care provision as their responsibility. Second, the participants communicated constant struggles with their own health and grandchild-care as well as positive/negative emotions associated with the care provision. Third, most of the participants did not fully understand the developmental needs of their primary-grade grandchildren. Fourth, the participants articulated concerns for their primary-grade grandchildren's learning, peer interactions, school adjustment, and extra-curricular activities. Lastly, the participants all agreed on hoping to raise grandchildren with good personality traits as members of a society and to have them fill the gap from the loss of their parents. Conclusion: Although most participants accepted the current circumstances as their obligation, they still noted difficulties in child-care provision. Given the developmental needs of grandchildren and the resource needs of grandparents, proper and continuous intervention approaches should be developed/provided.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.117-121
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• 2016

Background: Definition and grouping of initiating events (IEs) are important basics for probabilistic safety assessment (PSA). An IE in a spent fuel reprocessing plant (SFRP) is an event that probably leads to the release of dangerous material to jeopardize workers, public and environment. The main difference between SFRPs and nuclear power plants (NPPs) is that hazard materials spread diffusely in a SFRP and radioactive material is just one kind of hazard material. Materials and Methods: Since the research on IEs for NPPs is in-depth around the world, there are several general methods to identify IEs: reference of lists in existence, review of experience feedback, qualitative analysis method, and deductive analysis method. While failure mode and effect analysis (FMEA) is an important qualitative analysis method, master logic diagram (MLD) method is the deductive analysis method. IE identification in SFRPs should be consulted with the experience of NPPs, however the differences between SFRPs and NPPs should be considered seriously. Results and Discussion: The plutonium uranium reduction extraction (Purex) process is adopted by the technics in a model reprocessing plant. The first extraction cycle (FEC) is the pivotal process in the Purex process. Whether the FEC can function safely and steadily would directly influence the production process of the whole plant-production quality. Important facilities of the FEC are installed in the equipment cells (ECs). In this work, IEs in the FEC process were identified and categorized by FMEA and MLD two methods, based on the fact that ECs are containments in the plant. Conclusion: The results show that only two ECs in the FEC do not need to be concerned particularly with safety problems, and criticality, fire and red oil explosion are IEs which should be emphatically analyzed. The results are accordant with the references.

• 대한간호학회지
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• 제24권3호
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• pp.499-510
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• 1994

The purpose of this study was to Identify the self-actualization level of Junior College Nursing Students and to analyze the variables that may be related to self-actualization. A convenient sample of 346 students were selected from three colleges located in Seoul and Kyungki-Province. The data were collected using a direct survey method from September17to October 2, 1992. The instrument used for this study was the self-actualization test modified by Kim & Lee(1983). The collected data were analyzed using percentages, means, 1-test, X$^2$-test, ANOVA and Pearson’s correlation coefficient, with the SPSSPC$^{+}$ Package. The results of this study are as follows : 1) The self-actualization level of subjects was moderate. The subjects showed higher scores in the areas of Self actualizing Values and Nature of Man than the standardized normal groups. The subjects showed lower scores in the areas of Inner Directed Existentiality, Self acceptance and Capacity for Intimate Contact. 2) The subjects attending day junior colleges showed higher scores in the areas of Time competent, Existentiality and Self Acceptance than those attending college in the evening. The subjects attending evening junior colleges showed higher scores in the areas of Spontaneity than those attending college by day. 3) The junior students showed higher scores in the areas of Feel-ing Reactivity than freshman. The students with no religion showed higher scores in the areas of existentiality than those who had a religion. The group who had the experience of failure on the college entrance examination showed lower scores in the areas of Nature of Man than those without this experience. Those who chose their major voluntary showed scores higher in the areas of I nor Directed, Self Actualizing Values, Spontaneity and Self regard than the unsatisfied group. The group satisfied with college life showed higher scores in the areas of Time Competent, Inner Directed, Self Actualizing Values and Self Regard than the unsatisfied group. In conclusion self actualization level depends on motivation of choice, satisfaction with nursing as a major and satisfaction with college life. Therefore, and effective guidance program is required to improve motivation and satisfaction with nursing as a major and with college life.