• 한국전기전자재료학회논문지
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• 제18권2호
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• pp.180-186
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• 2005

As a driving method of AC-PDP, Address-Display Separated(ADS) driving has been widely adopted for its simple architecture and low discharge failure rate. However, a high definition like a HDTV has defect of long addressing time by reason of a number of pixels. Priming effect isn't fully sustained because of long addressing time during the address period. Therefore, it has different wall charge and luminance of each addressing time in the sustain period. In this study, we suggest a new driving waveform on the address period to improve these defects. We applied a ramp waveform, instead of a square waveform, to an address period in ADS, for operating on the AC-PDP, which used the conventional gas [He-Ne-Xe]. When the ramp waveform is applied to the address period, we experimented for uniform wall charge and the improved luminance by sustained Priming effect at each addressing time in the sustain period.

• 산업경영시스템학회지
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• 제43권4호
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• pp.123-132
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• 2020

Currently, there are two types of trainer in Korea : basic and advanced. Both models have been in operation for more than 10 years, and compared to the early stage of operation, reliability has gradually improved and failure rates have also entered a trend of stabilization. Therefore, it is necessary to extend the maintenance period considering economic feasibility. This study investigates the three maintenance period calculation methods: NAVAIR 00-25-403 [17], DOD, U.S. [4], CERL and US Army [3], with intention to extend the maintenance period of the trainer from current 200 hours to 400 hours. In addition, the maintenance period was calculated by the three methods with actual operational data. Common standards and procedures were established to apply operational data to the existing maintenance period calculation methods, the required reliability indicators were derived, and the maintenance periods was calculated based on the results, additionally, a review on the field applicability of the three maintenance cycles was conducted. An on-site interviews were conducted with the calculation results, and 11 out of the 15 items were expected to be extended by 400 hours. It was suggested that the remaining 4 items could be extended to 400 hours by supplementing the inspection method through additional analysis such as functional analysis, inspection content verification, and site connection.

• 혜화의학회지
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• 제21권1호
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• pp.163-174
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• 2012

Objective: The primary objective this study was to evaluate the effect of Paljeong-san (PJS) pharmacopuncture treatment on against the glycerol-induced acute renal failure in rats. Methods: Glycerol injection decreased GFR (glomerular filtration rate) and increased urine volume, serum creatinine, BUN level, urine albumine secretion and fractional excretion of Na+, K+. PJS was selected in the basis of invigorating kidney which can eliminate pathogens. Rats were treated with PJS pharmacopuncture on Shin-shu (BL23) and Chon-chu (ST25) point for 3 days, followed by 50% concentration of glycerol injection ($5m{\ell}/kg$ body weight). Results: After the 3 days treatment period, Paljeong-san (PJS) pharmacopuncture treatment improved renal function. In addition, Glycerol injection increased lipid peroxidation, and decreased Na-K-ATPase in renal cortex and which were prevented by PJS treatment. Conclusion: This study suggests that Paljeong-san (PJS) pharmacopuncture treatment show favorable effect on glycerol-induced acute renal failure in rats.

• Journal of Chest Surgery
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• 제16권2호
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• pp.184-189
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• 1983

Between 1958 and 1982, 70 patients have undergone pericardiectomy for constrictive pericarditis at the Thoracic Department of Seoul National University Hosp. 58 males and 12 females, with an average age of 27 years [ranging 3 to 60 years], of which 55% were between 10 and 30 years old, were treated. Eight patients died, of whom 4 were in the immediate postoperative period, less that 24 hours after operation. The cause of death was myocardial failure in 3 patients and hypotension during operation in one patient. The remaining four deaths occurred between the fifth and eighteenth postoperative day, and the causes of death varied: bilateral phrenic nerves injury, congestive heart failure, dissemination of tuberculosis, and cardiac arrest. Two patients suffered from congestive heart failure pre-and postoperatively due to the associated valvular heart disease. There were 8 wound infections on which resulted in perichondritis of costal cartilages requiring segmental resection 2 months later. There was one postoperative bleeding requiring immediate reopening for bleeding control. Tuberculosis was confirmed as the cause of constrictive carditis in 27 patients [39%]. Acute pyogenic pericarditis was precursor in 8 patients [11%]. In 2 patients [2.9%], the constrictive pericarditis developed following OHS. Both suffered from congestive heart failure postoperatively due to the residual valvular heart disease. In the others, the cause of the constrictive pericarditis was considered idiopathic or non-specific inflammation.

• Journal of Power Electronics
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• 제3권3호
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• pp.145-150
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• 2003

Reliability, availability, and cost have been the major concerns for photovoltaic hybrid systems since their beginning as primary sources for much critical applications like communication units and repeaters. This paper descnbes the performance of two hybrid systems, photovoltaic-battery, wind-turbine coupled with the public-grid (PVBWG) hybrid system and photovoltaic-battery, wind-turbine coupled With the diesel generator (PVBWD) hybrid system The systems are sized to power a typical 300W/48V de telecommunication load continuously throughout the year Such hybrid systems consist of subsystems, which in turn consist of components Failure of anyone of these components may cause failure of the entire system. The reliability and availability basics, and estimation procedure for the two proposals are introduced also in this paper. The PVBWG and PVBWD system configurations are shown with the relevant mean-time-between-faIlure (MTBF) and failure rate (${\lambda}$) of each component. The characteristics equations of the two systems are deduced as a function of operating hours and the percentage of sun and wind availabilities per day. The system probability failure as well as the reliability is estimated based on the fault tree analysis technique. The results show that, by using standard or normal components MTBF, the PVBWG is more reliable and the time of periodic maintenance period is more than one year especially in the rich sites of both sun and wind, but PVBWD competes else Also, in the first five years from the system installation, the system is quit reliable and may not require any maintenance. The results show also, as the sun and wind are available, as the system reliable and available.

• Journal of Korean Biological Nursing Science
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• 제19권4호
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• pp.227-240
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• 2017

Purpose: The purpose of this review was to identify the current status of nursing studies on heart failure (HF) patients in South Korea and to suggest future study direction. Methods: A literature review of databases such as KoreaMed, KERIS and nursing and allied health journal were searched with key terms 'heart failure' and 'nursing' for the period from January 2000 to February 2017. A total of 35 studies including 28 articles and 7 theses met the inclusion criteria. Results: Twenty-seven out of 35 studies were observational studies on outpatients and most of the studies did not mention the ejection fraction and New York Heart Association functional classification class (NYHA class) in the inclusion criteria. Self-care and health-related quality of life as psychological factors, and physical activity as a biological factor, were used as main variables. However, we found it difficult to understand how much score indicates better quality of life because of an inconsistent and wide score. In quality assessment, 8 intervention studies had no serious flaws. Conclusion: Further studies should consider more biological and social factors influencing HF. The quality assessment with respect to nursing intervention studies in HF showed that randomized and double-blind trials are needed.

• 품질경영학회지
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• 제39권2호
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• pp.217-233
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• 2011

This paper introduces service failure management on internet shopping environment. The purpose of this study is to find and improve service failure modes at the time of customer's complaint thereby reducing that. To achieve this purpose, this study combines the Service Blueprint which describes the online shopping process and FMEA which finds each encounter of service failures and proposes how to recover them. First of all this study generates internet shopping process using Service Blueprint then matches customer's purchase decision making process and company's service provide process. After this process customer complaint types in real purchasing process are fell in according to their occurrence and more frequently occurred complaint is more risky. Finally 6 Risk Priority Numbers(unfair exchange/return policies, slow response/poor customer service support, purchase arrived later than promised/deliverly service dissatisfaction, dissatisfaction short period to take back/exchange/cancels order, A/S or handle defective item) are extracted and suggest their improvement.

• 대한간호학회지
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• 제54권1호
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• pp.93-105
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• 2024

Purpose: The study aimed to understand the semantic structure and nature of the disease experience of kidney transplant recipients with kidney graft failure by applying phenomenological research methods. Methods: Data were collected between February and September 2021 through individual in-depth interviews with 12 kidney transplant recipients with kidney graft failure. Colaizzi's phenomenological analysis was used to analyze the meaning of the participants' illness experiences. Results: 5 theme clusters and 15 themes were derived. The five theme clusters are as follows: (1) First transplant giving me a second life; (2) Body and mind becoming sick again; (3) Waiting for a re-transplant with hope and worry; (4) Life supported by gratefulness; (5) Having control over my own life. Conclusion: This study shows that kidney transplant recipients with kidney graft failure experience physical and psychological difficulties during the long disease period and require help from many people, including family members, friends, colleagues, and health care providers, to overcome their difficulties.

• Journal of Chest Surgery
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• 제16권2호
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• pp.139-146
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• 1983

Between 1974 and 1982, 31 patients from 7 to 15 years of age have undergone valve replacement for their acuqired cardiac valvular diseases at Seoul National University Hospital. Furteen patients (45.2%) had a definite history of rheumatic fever and only 4 patients (12.9%) had atrial fibrillation on their preoperative electrocardiograms. Characteristically, the valvular lesions were ones of insufficiency with or without associated stenosis in all patients except only one whose mitral valve was tightly stenotic. Thrity-seven valves were replaced in 31 patietns including a case of successful replacement of his failed xenogragt mitral valve : 4 mechanical valves were used in 3 patients and 33 xenograft valves were used in the remaining 28 patients. The size of the valves were not the major problem at the time of opertion because most of the patients had a dilated heart from disease. There were 3 diaths within 30 days of surgery (9.7% operative mortality rate) and 3 late deaths (9.7% late mortality rate) with an overall mortality rate of 19.4%. Twenty-eight early survivors were followed up for a total of 488 patient-months. Thromboembolic complications occurred in 5 patients with 2 deaths: cmbolic rate of 17.9% or the actuarial embolic incidence of 12.29%/patients-year. four xenograft tissue valves in 4 patients had failed during the period from 19 to 41 months of surgery with an overall valve failure rate of xenograft of 14.3% or the actuarial incidence of 9.84% failure/patient-year. One of these 4 patients had required replacement of his failed mitral xenograft valve which had severe calcification and tissue disruption with primary tissue failure rate of 3.6% or the actuarial incidence of 3.13% failure/patient-year. The actuarial survial including the operative morality was 50.0% at 5 years of surgery. /the actuarial incidence free from thromboembolism in bioprosthetic group was 85.4% at 42 months, while it was 33.4% in mechanicial group at 60 months after operation. The actuarial incidence free from overall valve failur of 100.0% until 18 months after surgery was followed by a rapid decrease during the next 2-year period, and it was only 17.8% at the follow-up end of 42 months after surgery. It was suggested that the major advantage of low thrombogenecity with xenograft valve should be balanced against the high incidence of accelerated valve failure when it is used in children whose age is younger than 15 years old. The possible role of recurrent rheumatic attacks to the early failure of xenograft tissue valve was also discussed.

• 한국해안·해양공학회논문집
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• 제36권2호
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• pp.50-60
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• 2024

우리나라 해안공학계에서 신뢰성 기반설계가 빠르게 체화되는 계기를 제공하기 위해 다 수의 한계상태를 지닌 직립방파제 신뢰성 해석과 신뢰성 기반 최적 설계를 우리나라를 대표하는 항이 운영 중인 부산, 군산 전면해역을 대상으로 수행하였다. 이 과정에서 상당한 정도의 신뢰성 해석을 수행하기 위해, 특정 재현 빈도의 설계 파 사용은 지양하였으며, 직립방파제의 파괴 여부를 결정하는 확률변수인 파력, 양력, 전도 모멘트에 내재한 불확실성은 장기 파랑 관측자료를 빈도 해석하여 얻은 확률모형을 사용하여 기술하였다. 직립식 방파제의 한계상태는 활동, 전도, 지지력을 고려하여 세 개로 구성하였으며, 파력과 양력, 모멘트 사이의 밀접한 상관성은 Nataf 결합확률분포를 사용하여 기술하였다. 모의 결과, 쉽게 예상해볼 수 있듯 활동만을 고려하는 경우 파괴확률이 과소하게 산출되는것을 확인하였으며, 특정 재현 빈도에 근거한 설계 파랑으로는 방파제 파괴확률을 일정하게 담보할 수 없다는 것을 확인하였다. 이에 비해 신뢰 지수가 𝛽 = 3.5~4를 충족하도록 최적 설계된 방파제는 두 해역에서 모두 균질한 파괴확률을 확보하는 것으로 모의 되었다.