• Clean Technology
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• v.27 no.1
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• pp.93-103
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• 2021

As the seriousness and necessity of responding to climate change and reducing carbon emissions increases, countries around the world are continuing their efforts to reduce greenhouse gases. Among various efforts, research on CCUS, capturing and utilizing carbon dioxide generated when using carbon-based fuels, is actively being conducted. Studies on pressurized oxy-fuel combustion (POFC) that can be used with CCUS are also being conducted by many researchers. The purpose of this study is to analyze basic information related to the flame structure and pollutant emissions of pressurized oxy-fuel combustion. For this, a counter-flow diffusion flame model was used to analyze the combustion characteristics according to pressure and oxygen concentration. As the pressure increased, the flame temperature increased and the flame thickness decreased due to a reaction rate improvement caused by the activation of the chemical reaction. As oxygen concentration increased, both the flame temperature and the flame thickness increased due to an improvement to the reaction rate and diffusion because of a change in oxidizer momentum. Analyzing the related heat release reaction by dividing it into three sections as the oxygen concentration increased showed that the chemical reaction from the oxidizer side was subdivided into two regions according to the mixture fraction. In addition, the emission index of NO classified according to the NO formation mechanism was analyzed. The formation trend of NO according to each analysis condition was presented.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.116-119
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• 2004

The existing monitoring and control systems of utility-pipe conduit (power tunnel, cable tunnel etc) have established communication lines using optical fiber, leaky coaxial cable (LCX), and several kinds of control cable. Due to the properties of the used media, the cost of equipment is considerably high and the maintenance of the system is difficult. Also, the term of carrying out is long so that the extension of the system is in difficulty. Now it is desirable to adopt Power Line Communication (hereinafter, PLC) technology in the monitoring and control systems and use the existing low-voltage power-line for lamplight as communication line. This will lead the reduction of the construction cost and the easy maintenance of the system. In this paper, we research the characteristics of PLC in conduit, design and manufacture the field test system, and analyze the performance of the system by field test. Then, we introduce the reliable monitoring and control system of utility-pipe conduit using PLC.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.3
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• pp.273-288
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• 2010

In this paper, we propose a cooperative multi-relay scheme for a secondary system to achieve spectrum access along with a primary system. In the primary network, a primary transmitter (PT) transmits the primary signal to a primary receiver (PR). In the secondary network, N secondary transmitter-receiver pairs (ST-SR) selected by a centralized control unit (CCU) are ready to assist the primary network. In particular, in the first time slot, PT broadcasts the primary signal to PR, which is also received by STs and SRs. At STs, the primary signal is regenerated and linearly combined with the secondary signal by assigning fractions of the available power to the primary and secondary signals respectively. The combined signal is then broadcasted by STs in a predetermined order. In order to achieve diversity gain, STs, SRs and PT will combine received replicas of the primary signal, using selection combining technique (SC). We derive the exact outage probability for the primary network as well as the secondary network. The simulation results are presented to verify the theoretical analyses.

• Journal of Korean Clinical Nursing Research
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• v.18 no.1
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• pp.171-181
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• 2012

Purpose: This study was conducted to identify the clinical characteristics and risk factors on the occurrence of metabolic syndrome (MS), and to examine factors affecting the severity of coronary artery diseases in patients with acute myocardial infarction (AMI). Methods: A total of 894 patients who had admitted C national university hospital from 2008 to 2010 participated in this study. Collected data were lipid profiles, abdominal circumference, blood pressure, fasting blood sugar (FBS) level, participants' demographic data and other risk factors by interview, measurement, and review of participants' medical records. MS was defined according to modified National Cholesterol Education Program Adult Treatment Panel III and Asia-Pacific Criteria. Results: The participants' mean age was 64.7 (${\pm}11.0$) years and 65% was male patients. The participants' with MS was 37.6% in men and 71.4% in women. According to binary logistic regression analysis, high FBS (95% CI 1.7-2.0) and lower high-density lipoprotein (HDL) cholesterol (95% CI 1.1-1.9) were independent predictors of severe coronary artery disease. Conclusion: These risk factors of severe coronary artery disease will be utilized as an important basic data in part of management, education, and countermeasure of patients with both MS and AMI.

• Journal of Korean Critical Care Nursing
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• v.4 no.1
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• pp.11-24
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• 2011

Purpose: The purpose of this study was to grasp the subjectivity of the nurses toward DNR (Do not resuscitation) order. Methods: Q methodology was employed to explore the nurses' subjectivity. Q population consisted of 292 statements that were obtained through individual in-depth interviews targeting 30 employees(nurses, doctors, staff members) and literature review. Finally, 30 nurses classified 34 statements using a 9 point scale. Results: The current survey that probed into the subjectivity of the nurses relative to DNR order abstracted four categories. The first type (restrictive acceptance type) perceived the determinants of DNR as the patient's hopeless state. The second type (evidence-based type) emphasized the decision based on the guideline. The third type (medical personnel-centered type) showed the characteristic that depends passively on the professional judgement. The fourth type (rationalistic type) emphasized rational characteristic that DNR decision needs to be made by considering several situations such as economic and psychological burden of family and the quality of life. Conclusion: These types of nurse's perception need to be considered in the nurses' continuing educational program in order to confront affirmatively and positively with ethical dilemma.

• Korean Journal of Adult Nursing
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• v.28 no.1
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• pp.61-70
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• 2016

Purpose: This study aimed to identify the mediating effect of the resilience on the relationship between type D personality and compliance of Coronary Artery Disease (CAD) patients. Methods: The subjects were 236 CAD patients who visited the cardiology outpatient clinics of D University Medical Center in B City in Korea. The type D personality, resilience, and compliance of subjects were measured using structured questionnaires from July to August, 2014. The mediating effect was analyzed by a multiple hierarchical regression. Results: The subjects with type D personality accounted for 30.9% of all study subjects. The resilience and compliance of type D subjects were significantly lower than those of non type D subjects. There was a significant correlation between resilience and compliance. The direct effect of type D personality on compliance was not significant (${\beta}=-.07$, p=.243), while the indirect effect of type D personality on compliance via resilience was significant (${\beta}=.23$, p<.001). Conclusion: On the basis of above results, it can be concluded that the resilience had completely mediating effect on the relation between type D personality and compliance of CAD patients. Further studies need to be done to develop the intervention enhancing resilience of CAD patients with Type D personality.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1142-1144
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• 1997

A case of fatal hematemesis due to an aberrant right subclavian arterioesophageal fistula which is a rare complication of the vascular ring is presented. A 42-year-old man with multiple injury by traffic accident presented severe upper gastrointestinal bleeding and was taken emergent operation. He was keeping tracheostomy tube and nasogastric tube for 7 weeks. We could find an aberrant right subclavian arterioesophageal fistula through left thoracotomy which was made by irritation of the prolonged nasogastric ube. We carried division of the aberrant right subclavian artery and fistulectomy. He was doing well postoperatively. But massive bleeding occurred at the fifth postoperative day. We performed emergent reoperation at CCU and found the tear point on the suture site of the aorta, which might be developed due to irritation of the chest tube andfor infection of the surrounding tissues. He was expired at the 8th postoperative day due to ischemic brain damage.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.119-120
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• 2015

ITER 한국사업단은 AC/DC Converter 최종설계검토(FDR)를 2014년 4월에 끝내고, 제작에 관련된 준비사항 점검인 MRR (Manufacturing Readiness Review)를 2014년 10월에 수행하였다. 1차 제작공정인 CCU/L 컨버터와 관련 I&C System은 2014년 11월부터 제작에 착수하여 곧 FAT(Factory Acceptance Test)를 앞두고 있다. 이 시점에서 중요한 것은 FAT를 앞둔 제작된 기기가 ITER의 설계요건을 충분히 만족하는지에 대한 검증을 하는 것이다. 본 논문은 초전도자석 및 컨버터의 이상상태 또는 고장 시에 장치를 보호하는 중요한 Plant Interlock System(PIS)이 ITER의 설계요건을 충실히 반영하였는지 확인하기 위한 요건추적매트릭스(RTM) 기법을 소개하고, Interlock System의 중요기능인 사고 시 초전도 코일에 충전된 에너지를 급속 방전하기 위한 장치인 DLIB와의 연계기능에 적용한 예를 보이고자 한다.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.221-222
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• 2015

ITER AC/DC Converter의 부하는 초전도 코일이며 이에 필요한 컨버터는 총 6종류(2상한:TF, 4상한:PF, CS, VS, CCU/L, CCS)가 있다. 이중 VS 컨버터(${\pm}1050V$, ${\pm}22.5kA$)는 6대가 직렬로 접속되어 운전되고 CS 컨버터(${\pm}1050V$, ${\pm}4.5kA$)는 4대가 직렬로 접속되어 운전한다. 이들 컨버터용 제어기의 개발 단계에서 실 부하상태를 준비하는 것은 어렵기 때문에 $RTDS^{TM}$ (Real Time Digital Simulator)를 이용하여 제어 대상인 High Power 부분과 초전도 코일의 동적 시스템 모델을 HILS(Hardware-in-the-Loop Simulation)로 구축하였다. 본 논문에서는 HILS 구축에 대한 상세한 내용과 이를 활용하여 Control 시스템을 검증한 결과를 서술하였다.

• Journal of Korean Clinical Nursing Research
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• v.18 no.1
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• pp.149-158
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• 2012

Purpose: The purpose of this study was to investigate incidence and factors related to diarrhea in an intensive care unit (ICU). Methods: Retrospective correlational design was used. Data were collected from reviewing medical records of 210 patients stayed at an ICU in one university hospital, Seoul. Patients were included in the study if they 1) had no gastrointestinal disorders or fecal incontinence before coming to the ICU, 2) stayed longer than 5 days at the ICU, 3) were not on stool softners, 4) were without abdominal surgery, and 5) were 20-year-old or older. Results: The incidence of diarrhea was 27.1%. Durations of ICU stay, antibiotics administration, and enteral feeding were found to be statistically significant factors correlated with diarrhea. The enteral feeding was the significant predictors of the diarrhea in ICU. Conclusion: Since characteristics of diarrhea in ICU patients is shown to be multifactorial, nursing strategies for evaluating and managing related factors are recommended.