• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1280-1290
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• 2016

This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous models, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage.

• 한국압력기기공학회 논문집
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• 제16권2호
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• pp.18-24
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• 2020

When a damage occurs in the nuclear fuel burning in the reactor, fission products that should be in the nuclear fuel rod are released into the reactor coolant. In this case, sipping test, a series of non-destructive inspection methods, are used to find leakage in nuclear fuel assemblies during the power plant overhaul period. In addition, the sipping test is also used to check the integrity of the spent fuel for moving to an intermediate dry storage, which is carried out as the first step of nuclear decommissioning, . In this paper, the principle and characteristics of the sipping test are described. The structure of the sipping inspection equipment is largely divided into a suction device that collects fissile material emitted from a damaged assembly and an analysis device that analyzes their nuclides. In order to make good use of the sipping technology, the radioactive level behavior of the primary system coolant and major damage mechanisms in the event of nuclear fuel damage are also introduced. This will be a reference for selecting an appropriate sipping method when dismantling a nuclear power plant in the future.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제8권11호
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• pp.449-456
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• 2019

본 논문은 진공을 이용한 흡착방식과 바퀴형 이동방식을 사용하는 벽면 이동로봇의 구성과 이러한 임베디드 환경에 적합하고 기계학습에 기반한 벽면 균열 자동 검출 알고리즘의 성능 비교에 관한 연구이다. 임베디드 시스템 환경에서 객체 학습을 위해 YOLO 등 최근에 시도된 학습 방법들을 적용하여 성능을 비교, 검토하였으며 기존의 에지 검출 알고리즘들과도 성능을 비교하였다. 결국, 본 연구에서는 균열검출을 잘하며 임베디드 환경에도 적합한 최적의 기계학습방법을 선택하고 기존 방법과 성능을 비교하여 우수성을 제시하였다. 또한, 검출된 균열의 영상을 저장하고 위치 정보를 추정하여 균열에 대한 정보를 관리자 기기로 전송하는 지능적인 문제해결 기능을 구축하였다.

• Journal of Chest Surgery
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• 제28권6호
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• pp.542-548
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• 1995

The goal of this study is to develop an effective control system for cardiac output regulation based upon the preload and afterload conditions without any transducers and compliance chambers in the moving actuator type total artificial heart. Motor current waveforms during the actuator movement are used as an input to the automatic control algorithm. While the current waveform analysis is performed, the stroke length and velocity of the actuator are gradually increased up to the maximum pump output level. If the diastolic filling rate of either right or left pump begins to exceed the venous return, atrial collapse will occur. Since the diastolic suction acts as a load to the motor, this critical condition can be detected by analyzing the motor current waveforms. Every time this detection criterion is met, the control algorithm decreases the stroke velocity and length of the actuator step by step just below the critical detection level. Then, they start to increase. In this way the maximum pump output under given venous return can be achieved. Additionally the control algorithm provides some degree of afterload sensitivity. If the aortic pressure is detected to exceed 120 mmHg, the stroke length and velocity decrease in the same way as the response to the preload. Left-right pump output balance is maintained by proper adjustment of the asymmetry of the stroke angle. In the mock circulatory test, this control system worked well and there was a considerable range of stroke volume difference with adjustment of the asymmetry value. Two ovine experiments were performed. It was confirmed that the required cardiac output regulation according to the venous return could be achieved with adequate detection of diastolic function, at least in the in vivo short-term survival cases[2-3 days . We conclude that this control algorithm is a promising method to regulate cardiac output in the moving actuator type total artificial heart.

• Advances in pediatric surgery
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• 제1권1호
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• pp.53-58
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• 1995

기관식도루를 동반하지 않은 원간격결손 식도폐쇄증 1예를 미리 조성한 위루와 경구를 통하여 주기적 부지를 함으로써 식도길이를 확장하여 식도-식도단단문합술로 식도의 개통복원을 할 수 있었음을 경험하였다. 이때 상부식도맹단부로부터 이중관을 이용한 지속적인 섬프배액술이 경과에 아주 긴요하며, 수술시 식도길이의 여유를 위하여 식도근환상절개술을 한 후에는 근절개부위의 협착 발생 가능성에 항상 주의하여 술 후 조기(술 후 2-4주)에 추시함이 꼭 필요하다고 생각하였다. 식도부지를 할 때에는 길이 뿐만 아니라 직경확장(특히 하부식도에서)에도 관심을 갖이면 더욱 좋은 결과를 얻을 수 있다고 판단된다.

• 해양환경안전학회지
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• 제26권6호
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• pp.689-697
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• 2020

위험유해물질(HNS, Hazardous and Noxious Substances)은 해상운송 과정에서 다양한 사고에 노출되어 있어 많은 양이 바다에 유출될 우려가 있다. HNS 유출에 따른 해양환경의 손상은 유류 유출에 의한 손상보다도 훨씬 큰 것으로 알려져 있다. 특히 해저로 침강하여 침적되는 HNS는 해저생태계에 돌이키기 어려운 피해를 주게 되므로, 반드시 회수되어야 한다. 해저로부터 HNS를 회수하기 위해서는 해저침적 HNS에 대한 정확한 탐지, 안정화 처리 및 회수를 위한 절차와 장비가 필요하다. 그 중에서도 기계적 회수장치를 개발하기 위해서는 성능지표를 이용하여 성능요건을 선정하고, 이를 토대로 기계적 회수장치에 대한 개념설계가 이루어져야 한다. 따라서 본 연구에서는 해저침적 HNS의 회수 절차에서 요구되는 기계적 회수장치에 대한 개념설계안을 제시하였다. 개념설계안으로 해저침적 HNS를 회수하기 위한 기본 시나리오를 제시하고, 자체적 밀폐 성능을 가지는 흡인 기초를 활용하는 방안을 채택하였다. 기계적 회수장치는 흡인 기초, 오염 방지, 펌프 시스템, 제어 시스템, 모니터링 장비, 위치정보 장비, 이송 장비, 탱크로 구성된다. 이러한 개념설계안은 기계적 회수장치의 부품 및 형상을 결정하는 기본설계에 반영되어 활용될 것으로 기대된다.

• Journal of Chest Surgery
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• 제8권1호
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• pp.19-28
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• 1975

The thoracoscopic study was reported on 21 cases of spontaneous pneumothorax requiring surgical management, and clinical values of thoracoscopic examination on spontaneous pneumothorax were also discussed. patients were treated in the Department of .Thoracic Surgery, Hanyang University Hospital for the period of two Years from May 1972 to April 1974. For exact detection of etiologic factors on spontaneous pneumothorax, the thoracoscopic examination in the intrapleural space was performed in parallel with X-ray study. this study, the difference of diagnostic and therapeutic significance between radiological and thoracoscopic findings were observed and compared simultaneously. The results are summerized as follows: Patients age was distributed between 3 and 70 years old with highest incidence in the age group of sixty decade [33. 3%], and sex ratio of male to female was 5:2. The tuberculous processes which developed superficial subpleural layer in the lung parenchyme, on the pulmonary surface could be observed by thoracoscopic examination in a characteristic picture. detection ratio of pulmonary tuberculosis by the radiologic study to that by thoracoscopy was 8:2. The adhesion between the visceral and the parietal pleura which could possibly make a rupture of the alveola and the visceral pleura was found to be localized in a small area of the lung surface. The other part of the lung surface was free of the adhesion and, therefore, the movement of the lung took place completely without any difficulty. The ruptured orifice of the pleura and pathological changes surrounding the orifice can be detected by thoracoscopy, but not by other means such as radiologic examination. A single tuberculous bleb and multiple emphysematous blebs were found on 6 cases out of 21 cases of spontaneous pneumothorax. Among these cases, radiologic Study revealed the bleb only in one patient. On the other hand, the blebs were found in all the six patients by means of thoracoscopic examination. It gives the detection ratio of bleb by radiologic study to that by thoracoscopy was 1:6. By thoracoscopy, the rupture on the lung surface were visualized on the 10 patients out of a total of 21 patients [10 patients of visual rupture]. However, the rupture of the pleura was not observed on the rest of 11 patients even by thoracoscopic examination [11 patients of non visual rupture]. Five patients [50%] out of ten who had the visual rupture on the lung surface was required a surgical operation to remove pneumothorax. For the patients who were detected to have the visual rupture of the pleura by thoracoscopy, be considered in the early stage of closed thoracostomy. of 21 patients, 16 patients [11 patients of non visual rupture of the pleura and 5 patients of visual rupture of the pleura] who received no surgical management, were treated with closed thoracostomy with continuous suction, and the` pneumothorax was healed completely up in each cases. Therapeutic measures for the remaining 5 patients of visual rupture of the pleura who were subjected to surgical approach for radical treatment of spontaneous pneumothorax were accordingly complicated, and the following different procedures were properly indicated case by case, that is, rib resection thoracostomy, simple closure of ruptured visceral pleura, wedged resection of the lung, and lobectomy.

• 사물인터넷융복합논문지
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• 제3권1호
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• pp.25-31
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• 2017

미래형 신도시와 최신 아파트들이 건설되며 일반 가정 실내에도 IoT기술이 대거 접목되어 구축된다. 그중 사람들을 쾌적하게 해주는 공기순환기도 내장되어 건설되는데, 공기순환기의 공기를 흡입하는 흡입구와 배출하는 배출구는 실내 곳곳에 설치되어진다. 하지만 이는 중앙 스위치로 on / off 밖에 없기에 조절이 불가능하다. 또한 막심한 전기소모로 인한 다량의 전기세가 나오도록 하며 많은 전기소모는 결국 자원낭비로 이루어진다. 이를 보완하고자 실내 내장형 공기청정기에 미세먼지 감지 장치를 통하여 조절되며 구동되도록 만들어 전기를 절약하는 솔루션을 제안한다. 더불어 배출구는 실내 곳곳에 존재하기에 사람의 위치를 파악하여 홈 네트워크와 연결하여 편의성을 높여주거나 기체분석을 통하여 사용자의 건강을 체크하고 적절히 조절하는 헬스체크 솔루션을 함께 제안한다.

• 한국추진공학회지
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• 제14권6호
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• pp.60-68
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• 2010

본 연구에서는 팁 형상이 가스터빈 블레이드의 팁 열전달에 미치는 영향을 알아보기 위하여 선형 캐스케이드의 블레이드에 설치된 평면 팁, 스퀼러 팁, Groove 팁들에 대하여 열전달 계수가 측정되었다. 블레이드 팁에서의 열전달 계수는 색상검출방식에 기반을 둔 천이액정법을 이용하여 측정되었으며 각각의 팁 형상에 대하여 팁 간극은 블레이드 스팬의 1.5%와 2.3% 두 조건에서 실험을 수행하였다. 캐스케이드 출구 속도와 블레이드 코드길이에 기초를 둔 Reynolds 수는 $2.48{\times}10^5$ 이다. Groove 팁 표면에서의 열전달 계수는 평면 팁보다 낮게 측정되었으며, 특히 흡입면을 따라 경사진 홈이 파인 팁에서는 스퀼러 팁보다 낮은 열전달 계수가 측정되었다.

• 한국의료질향상학회지
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• 제14권1호
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• pp.55-59
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• 2008

Background : The purpose of inner cannula is to protect the upper air way and permit air to pass freely, in addition, to provide endotracheal suction, artificial respiration and to maintain adequate oxygen saturation. The tube needs to be sterilized for maintenance and cleanness of air way and for prevention of bronchospasm. However, it has been reported that there is no guideline for sterilization and many hospitals conduct their own sterilization methods, for example, once a day(13's general hospital), three times a day(The Catholic University of Korea ST Mary's hospital) or even no cleansing. Consequently, the QI team of our hospital suggested the SOP(standard operating procedure) of sterilization and evaluate cost and time effect in nursing. Method : 1) Benchmarking of 13's neurosurgery department of general hospital in Seoul 2) Investigation of test records of sputum culture from patients with intubation for tracheotomy 3) Check of results of O2 Sat. monitoring to confirm of maintaining opened air way Result : 1) Improvement of process: decrease of excess sterilization of inner cannula (from 3 times a day to once a day) 2) Cost effects: saving over 10 million won per one year 3) Providing better nursing: time effects (30 min a day) permit to conduct more nursing activities Conclusion : It can get Cost and time effects in nursing with improved sterilization method of inner cannula. It needs to do research on improvement of the monthly exchange protocol of outer cannula and provide supporting data for the proper exchange schedule. The result of additional microorganism detection from patients with new process needs to be evaluated further more.