• 한국산학기술학회논문지
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• 제18권3호
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• pp.493-500
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• 2017

본 논문은 서울도시철도공사 유피스 내 전동차관리 고장데이타(BOM)을 통해 지속적으로 관리된 데이터를 활용하여 노후 철도차량부품의 신뢰성분석을 하고 개선방안을 제시하고자 하였다. 분석대상인 서울도시철도공사 7호선 2차분 보조전원장치(Static Inverter)는 객실 내 각종 서비스장치에 전원을 공급하여 직접적으로 승객 만족도에 영향을 주는 핵심적인 장치이다. 경영정보시스템의 장기간에 걸친 필드데이타를 바탕으로 고장의 패턴을 분석하기 위해 운용환경 스트레스 인자를 고려한 통계 신뢰성분석을 하였다. 보조전원장치(Static Inverter)의 하절기 집중고장현상과 관련하여 고장과 온도 스트레스인자와의 상관성에 대해 통계적 분석을 하였고 IGBT 인버터의 수명분석을 통하여 수리 전 후의 온도 스트레스 인자의 영향을 분석해 보았다. 그리고 전동차 부하량과 외기온도의 두 변수를 고려한 최적운행조건을 분석하여 고장다수 발생조건과의 냉각용량차이가 발생함을 확인할 수 있었고, 이러한 분석을 바탕으로 최적의 운행을 위한 냉각용량차이를 줄일 수 있는 방안을 제시하였다.

• 대한간호학회지
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• 제42권3호
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• pp.333-341
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• 2012

Purpose: The purpose of this study was to test whether pre-operative visual information and parental presence had positive effects on anxiety, delirium, and pain in pediatric patients who awoke from general anesthesia in a post-surgical stage. Methods: This study used a non equivalent control-group post test design (n=76). Independent variables were provision of pre-operative visual information and parental presence for post-surgical pediatric patients in PACU (post anesthesia care unit). Dependent variables were anxiety, delirium, and pain in the pediatric patients measured three times at 10 minute intervals after extubation in the PACU. Measurements included Numerical Rating Scale for assessing state anxiety, Pediatric Anesthesia Emergence Delirium Scale by Sikich & Lerman (2004) for delirium, and Objective Pain Scale by Broadman, Rice & Hannallah (1988) for pain. Results: Experimental group showed significantly decreased state anxiety at time points-10, 20, and 30 minutes after extubation. Delirium was significantly lower at 10 minutes and 30 minutes after extubation in the experimental group. Pain was significantly lower at 10 minutes after extubation in the experimental group. Conclusion: The results of this study suggest that this intervention can be a safe pre-operative nursing intervention for post-surgical pediatric patients at PACU.

• 대한기계학회논문집A
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• 제30권11호
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• pp.1494-1501
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• 2006

Mechanical and physical properties of a copper alloy for a liquid rocket engine(LRE) combustion chamber liner application were tested at various temperatures. All test specimens were heat treated with the condition they might experience during actual fabrication process of the LRE combustion chamber. Physical properties measured include thermal conductivity, specific heat and thermal expansion data. Uniaxial tension tests were preformed to get mechanical properties at several temperatures ranging from room temperature to 600$^{\circ}C$. The result demonstrated that yield stress and ultimate tensile stress of the copper alloy decreases considerably and strain hardening increases as the result of the heat treatment. Since the LRE combustion chamber operates at higher temperature over 400$^{\circ}C$, the copper alloy can exhibit time-dependent behavior. Strain rate, creep and stress relaxation tests were performed to check the time-dependent behavior of the copper alloy. Strain rate tests revealed that strain rate effect is negligible up to 400$^{\circ}C$ while stress-strain curve is changed at 500$^{\circ}C$ as the strain rate is changed. Creep tests were conducted at 250$^{\circ}C$ and 500$^{\circ}C$ and the secondary creep rate was found to be very small at both temperatures implying that creep effect is negligible for the combustion chamber liner because its operating time is quite short.

• 대한기계학회논문집A
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• 제21권3호
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• pp.519-527
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• 1997

AISI 316 steel has been used extensively for heater and boiler tube of the structural plants such as power, chemical and petroleum plants under severe operating conditions. Usually, material degradation due to microcrack or precipitation of carbides and segregation of impurity elements, is occured by damage accumulated for long-term service at high temperature in this material. In this study, the effect of aging time on fracture toughness was investigated to evaluate the measurement of material degradation. The elastic-plastic fracture toughness behaviour of AISI 316 steel pipe aged at $550^{\circ}C$for 1h-10000h (the aged material) was characterized using the single specimen J-R curve technique and eletric potential drop method at normal loading rate(load-line displacement speed of 0.2mm/min) in room temperature and air environment. The fracture toughness data from above experiments is compared with the $J_{in}$ obtained from predicted values of crack initiation point using potential drop method.

• 한국압력기기공학회 논문집
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• 제14권2호
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• pp.24-31
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• 2018

In this paper, specimen tests with simulated large seismic conditions have been carried out to investigate damage characteristics such as structural deformation and crack initiation under seismic loading. The mechanical behavior of the specimens is predicted by numerical simulations and the strain-based damage evaluations are performed. Finite element analyses of the specimens under the simulated seismic loading at room and operating temperatures were carried out for low alloy steel and stainless steel materials. Peak strain amplitude, cumulative fatigue damage and cumulative strain limit damage are calculated considering the nature of cyclic loading. In all cases, the allowable damage criteria are exceeded at the time of observing cracks visually in the tests. Therefore, it is confirmed that the material behavior due to the large seismic loads can be predicted by the numerical method and the structural damage of the materials can be evaluated conservatively based on the strain criteria.

• 대한간호학회지
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• 제43권3호
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• pp.352-360
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• 2013

Purpose: In this study an examination was done of the effects of the American Society of PeriAnesthesia Nurses (ASPAN) Evidence-Based Clinical Practice Guidelines on body temperature, shivering, thermal discomfort, and time to achieve normothermia in patients undergoing total knee replacement arthroplasty (TKRA) under spinal anesthesia. Methods: This study was an experimental study with a randomized controlled trial design. Participants (n=60) were patients who underwent TKRA between December 2011 and March 2012. Experimental group (n=30) received active and passive warming measures as described in the ASPAN's guidelines. Control group (n=30) received traditional care. Body temperature, shivering, thermal discomfort, time to achieve normothermia were measured in both groups at 30 minute intervals. Results: Experimental group had slightly higher body temperature compared to control group (p=.002). Thermal discomfort was higher in the experimental group before surgery but higher in the control group after surgery (p=.034). It decreased after surgery (p=.041) in both groups. Time to achieve normothermia was shorter in the experimental group (p=.010). Conclusion: ASPAN's guidelines provide guidance on measuring patient body temperature at regular intervals and on individualized and differentiated hypothermia management which can be very useful in nursing care, particularly in protecting patient safety and improving quality of nursing.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권10호
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• pp.537-543
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• 1999

We fabricated a resistive superconducting fault current limiter (SFCL) of a meander type based on a YBCO film with the meander cross section of 5 $\times$ $10^{-6}$$cm^2$, and performed current limitation experiments. The film was coated quench current was 9.6 Apeak at 60 Hz, and the fast quench time was 0.63 msec. The resistance of the limiter continuously increased for three cycles dut to the temperature rise in the gold layer. The temperature of the current limiting element reached the room temperature in 11 msec, $150^{\circ}C$ in 54 msec after quench, and was saturated afterwards. For $45^{\circ}$and $90^{\circ}$faults the fast quench times were 0.56 msec and 0.26 msec, respectively. The quench time is believed to be reduced because the fault occurred when the current was either increasing or at the peak value. This limiter effectively limited the fault current to about 1/5 of the potential current with no SFCL right after the fault and to about 1/8.5 in three cycles. We confirmed that the gold layer effectively carried out the role of heat dissipation as the SFCL was quenched.

• 기록학연구
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• 제59호
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• pp.207-275
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• 2019

서울시자살예방센터(자살유족지원팀)와 자살유족 기록작업을 같이 했다. 자살유족지원팀은 자살유족의 심리지원을 위한 자조모임을 운영하고 있었다. 자조모임은 자살유족들이 모여 앉아 대화를 나누며 고통을 나누는 자리이다. 자조모임이 어느 정도 진행되자 모임에서 리더역할을 수행하는 성원들이 생겼다. 이들이 모여서 글을 쓰는 에세이 모임을 구성했다. 아들을 먼저 보낸 아버지(2명), 딸을 먼저 보낸 엄마(2명), 아들을 먼저 보낸 엄마(1명), 남편을 먼저 보낸 아내(1명). 이렇게 6명의 사람들이었다. 에세이 모임은 사직공원 앞에 자리를 잡은 한 공간에서 매주 만났다. 한쪽 벽면 전체를 차지하는 창문으로는 저녁이 들어오고 있었다. 낮에 있었던 일들은 지는 해를 따라 갔다. 10명(에세이 모임 6명, 자살유족지원팀 3명, 임상역사가 1명)이 탁자를 가운데 두고는 빙 둘러 앉았다. "자, 이제 무엇을 해야 할까?" 자살유족 기록작업은 2013~2014년에 있었다. 교육적으로 중요하고 특수한 환자의 임상사례를 학회, 잡지에 보고하는 것을 의학에서는 증례(證例. case report)라고 한다. 자살유족들과 같이 했던 기록작업을 증례로 소개하는 형식을 취해 정리했다. 증례 형식을 취한 것은 기록을 말하기 위해서는 인간을 말해야 하고, 인간을 말하기 위해서는 기록에 대해 말해야 하는 '인간과 기록의 상관성'이 중요하다고 보기 때문이다. 자살유족 기록작업에 대한 글이 이런 상관성에 대한 논의를 하는 데에 단초가 될 수 있다고 본다. 몇 년의 시간이 지났다. 당시 상황을 기록하는 데 필요한 객관적 거리가 확보되었을까? 그건 자신할 수 없지만, 작업의 과정과 방법을 서술하면서 '일상의 기록생산'에 대해 말해본다. 나아가 기록과 기록의 의미(인간)에 관한 몇 가지 단상을 말해본다. 1장에서는 기록의 출처를 다루었다. 그것은 기록하는 사람은 누구인가, 또는 누가 기록하는가 하는 것이다. 기록이 무엇인가 보다는 기록하는 사람은 누구인가 하는 물음이 앞서야 할 것 같다. 2장은 기록하는 형식에 관한 논의로 무엇을 위해 기록하는가, 무엇을 기록화 대상으로 삼는가, 어떤 기록형식이 필요한가 하는 것을 다뤘다. 3장과 4장은 일종의 기록방법론일 수 있는데, 3장에서는 쓰기, 4장에서는 대화를 다뤘다. 5장에서는 기록을 수용하는 의례를 다뤘다. 3개월이든 1년이든 자신이 기록했던 시간을 어떻게 수용하며 그 의미는 무엇일까 하는 것이다. 6장에서는 논의의 지평을 넓혀 일상의 기록생산, 일상적 아카이브를 다뤘다.

• 기본간호학회지
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• 제6권3호
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• pp.382-396
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• 1999

This study was attempted to prove the effect of emotional stability and vital signs applying music therapy program to the children admitted in the PICU. Data were collected from July to September, 1997. The subjects were 30 patients admitted in the PICU of 'S' University Hospital which were divided into two groups of experimental and control. Each group had 15 subjects. Method was nonequivalent control group pretest-postteset repeated design, observing vital signs and activity of subjects prior, during, and after the music intervention. The study tools were cassette tapes of 'Mother's music whose babies want to listen' and Space-lab patient monitor. Data were analyzed using the $SPSS/PC+;x^2$ test and t-test to analyze of the general characteristics ; paired t-test to prove hypotheses. Result were as follows; 1. Infants lower than seven months showed changing into stable vital signs from applying the music therapy, however infants from eight months to three-year old showed no change in vital signs. 2. Vital signs changed to stabilized condition in infants lower than seven months were heart rate and respiration rate. 3. The stability of vital signs during music therapy turned back to the previous state while terminating music therapy. 4. The effect of music therapy in the state of activity had on both infants group of lower than seven months and from eight months to three-year old, particularly more effective in the later group. I recommend follows on the base of above results ; 1. As above results shows, listening to music is effective on infants and toddler, intervention with music therapy appropriate to chidlren's age is hot recommended. 2. Comparative study with noise blocking effect and music therapy effect within the ICU environment be recommended. 3. The repeated study on when the exact time is and how many repeat the music therapy to show the above mentioned effect be recommended. 4. We recommend this music therapy to be done in the recovery room, isolating room, operating room as well as ICU.

• 대한간호학회지
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• 제37권4호
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• pp.558-567
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• 2007

Purpose: This study was to identify the effects of oropharyngeal sensory stimulation on a functional oral intake scale, ore-pharyngeal swallowing functions, and aspiration pneumonia symptoms with nasogastric tube insertion in stroke patients. Method: This study was a nonequivalent control group non-synchronized design. The subjects or the study were 32 patients who were hospitalized in Kosin Gaspel hospital. The experimental subjects were stimulated for $10{\sim}20$ minutes, 1 time per day. The intervention was implemented for 2 weeks. Result: Participants in the experimental group significantly received a higher score in ore-pharyngeal swallowing function than those in the control group. However the participants in the experimental group only got a high score in the function oralintake scale which doesn't imply a statistical significance. In addition, they didn't geta remarkably higher score in aspiration pneumonia symptoms than those in the control group. Conclusion: This study demonstrates that oropharyngeal sensory stimulation is effective in promoting recovery oro-pharyngeal swallowing function of nasogastric tube insertions in stroke patients.