• 한국유체기계학회 논문집
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• 제15권6호
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• pp.70-76
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• 2012

Recently, because people are taking a great interest in the water supply system and the related facilities are getting larger, the surge suppression is very important problem. The waterhammer occurs when the pumps are started or stoped for operation or tripped due to the power failure. As the waterhammer problems as a result of the pump power failure were very serious, these situations were carefully investigated. Accordingly, we carried out both numerical simulations and field tests to confirm the safety of Juam intake pumping station in which had the in-line pumps. In this paper, it was reviewed that the water supply system has the reliability on the pressure surge, in case the air chambers were installed at both the inlet and the oulet of the in-line pumping station. From the numerical simulations, we found that negative pressure occurred at the inlet disappeared and high pressure occurred at the outlet reduced due to the air chambers. And these results of numerical simulations verified by the field tests. The field tests carried out in case of normal start, normal stop, one and two of pumps emergency stop. By results of simulations and field tests, we are sure that Juam intake pumping station in which have the air chambers is safe for the waterhammer. In addition, we suggested the operation methods of facilities for safe maintenance of the pumping station.

• Journal of Chest Surgery
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• 제29권1호
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• pp.86-89
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• 1996

심실중격 결손을 동반한 대 혈관전위 에서 심방교체술(denning Procedure)후에 동맥전환술로 성공적인 치료를 했기에 보고하는 바이다 15개월 남아는 생후 8개월에 심방교체술(Senning operation)을 받은 이후에 심부전의 악화로 입원하였다. 혈관조영술상 우심부전, 삼천판막 폐쇄부전 및 잔류 심실중격 결손이 있었고, 심도자 검사에서 폐동맥심실/(LV/RV) 압력비는 75185여서 Senning (심방교체술)을 해체하고, 심실중격 결손은 포편 (patch)봉합하였으며, 폐동맥 밴딩하지않고 동맥전환술을 시행하였다. 수술후 심실기능이 정상으로 회복되었고 잘지내고 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.601-603
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• 2004

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.119-120
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• 2020

In order to establish an evaluation method that can quantitatively evaluate the fire safety of existing buildings in Korea, a stochastic approach is needed to consider the extent of damage in the event of actual fire, along with the operation and installation of facilities. Accordingly, as a basic study for the establishment of fire safety assessment methods for buildings, this study aims to analyze the results of safety inspection and the degree of damage caused by the operation of fire doors and fire shutters in order to derive the reliability of fire doors and fire shutters. As a result, the results of inspection of fire shutters and fire doors and the results of operation using fire statisticians are as follows. As a result of the inspection, the positive rate of fire doors was about 82% and 98% of normal operation was derived from the fire investigation.

• Archives of Plastic Surgery
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• 제34권6호
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• pp.741-747
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• 2007

Purpose: In order to determine the differences in speech outcome based on timing of operation in submucous cleft palate, we have reviewed our experiences in the Furlow palatoplasty over the last 11 years. Methods: From March 1996 to March 2006, 38 submucous cleft palate patients received Furlow palatoplasty. 10 developmentally delayed patients were excluded and 5 patients were lost to follow up. The rest 23 patients were reviewed. Speech was evaluated preoperatively and postoperatively, and speech therapy was performed accordingly. Perceptual speech assessment included hypernasality, nasal emission and articulation disorder. Cinefluorography was performed to aid perceptual assessment. Based on timing of operation, the patients were divided into 3 groups as following: Group A under 24 months(8 patients), Group B from 25 to 48 months(6 patients), and Group C over 49 months (9 patients). Except 1 patient under speech therapy yet, resultant speech was compared. 200707Results: The rate of abnormal speech was higher in Group C(3/9, 33.3%) than in Group A(0%) or B(0%). All 3 patients who had been discontinued of speech therapy from the parent's judgment had abnormal speech. The reason for the discontinuation was that the regular speech therapy was a burden at school age. Any patients who had continued speech therapy had normal speech. Conclusion: The results of our study shows that operative timing is associated with speech development. Maintenance of speech therapy was an important factor for normal speech development. It will be helpful to perform a palatoplasty before 48 months of age to complete speech therapy before the school age.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.923-930
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• 2020

현대 사회에서 다양한 전기기기들의 시스템 회로를 동작시키기 위해서는 여러 직류 전원이 필요하다. 회로의 정상적인 동작을 위해 안정된 직류의 공급이 필수적으로 요구되고 이를 위한 컨버터의 중요성은 매우 크다고 할 수 있다. 본 연구는 부하 변동에 상관없이 출력전압의 안정적인 공급을 유지할 수 있도록 승압형 DC-DC 컨버터인 KY 컨버터에 3-극점 2-영점 전압 제어기를 적용한 PWM DC-DC 컨버터 회로를 제안하였다. 제안된 컨버터 회로의 정상 동작 특성을 입증하기 위해 기존의 컨버터 회로와 비교하여 PSIM 시뮬레이션 프로그램과 PCB 기판에서의 회로 동작 실험을 수행하였다.

• Journal of Astronomy and Space Sciences
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• 제27권3호
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• pp.253-262
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• 2010

The electrical power system (EPS) of Korean satellites in low-earth-orbit is designed to achieve energy balance based on a one-orbit mission scenario. This means that the battery has to be fully charged at the end of a one-orbit mission. To provide the maximum solar array (SA) power generation, the peak power tracking (PPT) method has been developed for a spacecraft power system. The PPT is operated by a software algorithm, which tracks the peak power of the SA and ensures the battery is fully charged in one orbit. The EPS should be designed to avoid the stress of electronics in order to handle the main bus power from the SA power. This paper summarizes the results of energy balance to achieve optimal power sizing and the actual trend analysis of EPS performance in orbit. It describes the results of required power for the satellite operation in the worst power conditions at the end-of-life, the methods and input data used in the energy balance, and the case study of energy balance analyses for the normal operation in orbit. Both 10:35 AM and 10:50 AM crossing times are considered, so the power performance in each case is analyzed with the satellite roll maneuver according to the payload operation concept. In addition, the data transmission to the Korea Ground Station during eclipse is investigated at the local-time-ascending-node of 11:00 AM to assess the greatest battery depth-of-discharge in normal operation.

• 한국컴퓨터정보학회논문지
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• 제13권4호
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• pp.87-95
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• 2008

경계면 스캔 구조는 시험대상회로의 출력 값들을 캡쳐하여 스캔경로를 이용하여 TDO로 직렬출력하여 출력 값을 관찰할 수 있는 시험구조이며, Sample/preload명령어를 이용하여 시험대상회로의 특정한 한 순간의 출력만을 캡쳐하여 직렬출력하여 분석할 수 있다. 본 논문에서는 4비트 비동기 카운터회로를 시험대상회로로 선정하고, 정상동작중인 카운터의 특정 출력을 지정하여 특정한 순간의 정적인 출력이 아닌, 연속적인 동적인 출력 값들을 다른 출력결과의 영향 없이 지속적으로 TDO로 출력하여 관찰할 수 있는 선택 가능한 관측점을 가진 시험구조와 시험절차를 개발하였다. 본 논문에서 제안하는 선택 가능한 관측점을 가진 시험구조는 표준에서 정한 시험동작을 정상적으로 수행하며, 관측점의 설정을 위한 명령어가 추가되었다. 4비트 카운터회로에 제안된 선택 가능한 관측점 시험구조를 적용 설계하고, 관측점 설정 명령어를 사용한 시험절차를 Altera의 Max 10.0을 이용한 시뮬레이션을 통해 동작의 정확성을 확인하였다.

• Journal of Chest Surgery
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• 제18권1호
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• pp.104-110
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• 1985

The anomalous systemic arterial supply to the lung without sequestration is an uncommon congenital anomaly characterized by the presence of a part of lung tissue which supplied by an aberrant artery from the aorta or its branch and normal communication with the normal bronchial tree, and it was reported by Huber in 1777 first. It differs from bronchopulmonary sequestration in having normal bronchial communication from the remainder lung and normal lung histology. We experienced a case of anomalous systemic arterial supply to the lung without sequestration, which was confirmed preoperatively. The patient was 16 year old male and came to us with complaints of mild fever and profuse sputum with coughing. Chest film showed a ring-like soft tissue shadow in Rt. middle lung field. Aortogram revealed an aberrant artery originated from abdominal aorta at 12th thoracic vertebral level and supplying a part of Rt. lower lobe of lung. At. the time of operation, an aberrant systemic artery which originated from the abdominal aorta supplying the Rt. lower lobe was noted, and the bronchial communications were normal. After division and ligation of the aberrant artery, Rt. lower lobectomy was performed The postoperative courses were uneventful and the patient was discharged with good condition.

• 융합경영연구
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• 제7권1호
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• pp.1-14
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• 2019

Purpose - Currently, the economic globalization has become a common channel for China's enterprise to perform the international economic activities. Due to this background, this paper tries to analyze the influence of internationalization level on operation performance of enterprises. Research design, data, and Methodology - This paper aims at 296 companies going listed in Shanghai Stock Exchange and Shenzhen Stock Exchange. The data about the listed companies during the 12 years from 2005 to 2016 have been collected. Relevant theories, including the theory of comparative advantage, monopolistic advantage and product life cycle in developed countries as well as the small scale technology and state on localized technological capacities in developing countries, have been summarized to provide theoretical basis for the influence of international operation on operation performance of the enterprises. Moreover, the current status of international operation of China's enterprises, including the dynamic cause of the internationalization of China's enterprises, its competitive advantage and disadvantage as well as the interest and potential risk of the internationalization, have been also analyzed. Results - Via adopting the panel data to conduct an empirical analysis, It can be found that the relationship between international operation level and operation performance of China's enterprises can be expressed as the S-curve of declining, rising and declining again. Conclusions - This paper has taken the lead in using Ohlson corporate value model to fill the gap in the relevant researches in China. It can also provide guidance for the international operation of China's enterprises. Meanwhile, the two systems for international operation and performance evaluation index have been put forward. The performance of international operation can be classified as financial performance or corporate value so that the operation effect of those China's enterprises going abroad can be better evaluated.