• Geomechanics and Engineering
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• 제22권5호
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• pp.461-473
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• 2020

Natural rock mass contains defects of different shapes, usually filled with inclusions such as clay or gravel. The presence of inclusions affects the failure characteristics and mechanical properties of rock mass. In this study, the strength and failure characteristics of rock with inclusions were studied using the particle flow code under uniaxial compression. The results show that the presence of inclusions not only improves the mechanical properties of rock with defects but also increases the bearing capacity of rock. Circular inclusion has the most obvious effect on improving model strength. The inclusions affect the stress distribution, development of initial crack, change in crack propagation characteristics, and failure mode of rock. In defect models, concentration area of the maximum tensile stress is generated at the top and bottom of defect, and the maximum compressive stress is distributed on the left and right sides of defect. In filled models, the tensile stress and compressive stress are uniformly distributed. Failing mode of defect models is mainly tensile failure, while that of filled models is mainly shear failure.

• Journal of Chest Surgery
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• 제23권1호
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• pp.41-48
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• 1990

Thirteen patients underwent repair of atrioventricular septal defect [AVSD] from January 1980 to July 1989 at Kyungpook National University Hospital. Two patients had complete AVSD [Rastelli type A] and eleven patients had partial AVSD [ostium primum atrial septal defect and cleft of anterior mitral leaflet]. In all the patients of partial AVSD, atrial septal defect was closed with Dacron patch and the mitral cleft was approximated with interrupted simple sutures. In one patient of complete AVSD, one patch technique was used to close the atrial and ventricular septal defect, and in the other patient of complete AVSD, two patch technique was used. In six patients, there were associated anomalies; four had isolated ostium secundum ASD, two had patent foramen ovale. Postoperative complete A-V block was noted in a patient of partial AVSD, but it was returned to 1st degree A-V block 30 months later and in another case of partial AVSD, severe congestive heart failure [NYHA functional class IV] due to residual mitral insufficiency was developed postoperatively, but this patient was recovered to the state of functional class I after receiving mitral valve replacement. There was one hospital death [8 %] resulting from low cardiac output.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.192-199
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• 2016

With changes in insulated defects, the environment, and so on, new partial discharge (PD) data are highly different from the original samples. It leads to a decrease in on-line recognition rate. The UHF signal and pulse current signal of four kinds of typical artificial defect models in gas insulated switchgear (GIS) are obtained simultaneously by experiment. The relationship map of ultra-high frequency (UHF) cumulative energy and its corresponding apparent discharge of four kinds of typical artificial defect models are plotted. UHF cumulative energy and its corresponding apparent discharge are used as inputs. The support vector machine (SVM) incremental method is constructed. Examples show that the PD SVM incremental method based on simulated annealing (SA) effectively speeds up the data update rate and improves the adaptability of the classifier compared with the original method, in that the total sample is constituted by the old and new data. The PD SVM incremental method is a better pattern recognition technology for PD on-line monitoring.

• 대한기계학회논문집A
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• 제37권11호
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• pp.1315-1321
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• 2013

볼 베어링의 손상 상태를 예측하기 위한 방법을 본 논문에서 제시하였다. 손상 진전율을 추정하기 위해 확률적 베어링 피로 결함 진전 모델을 적용하고 잡음이 포함된 가속도 신호의 RMS 데이터를 이용하여 손상 상태와 고장 시간을 계산하였다. 확률적 결함 진전 모델의 파라미터는 볼 베어링에 대한 일련의 Run-to-Failure 시험을 수행하여 결정하였다. 가속도 RMS값으로부터 손상 진전율과 손상 상태를 추정하기 위해 규칙화된 파티클 필터 추정 방법을 적용하였다. 미래 시점에서의 손상 상태는 최근 측정된 데이터와 직전에 추정된 상태값을 이용하여 예측하였다. 예측된 손상 상태와 시험 데이터와 비교하여 개발된 방법의 적절성을 확인하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2001년도 창립10주년 제20회 학술발표회
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• pp.31-31
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• 2001

• 설비공학논문집
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• 제29권2호
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• pp.82-88
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• 2017

There are main issues of defect type that condensation, concrete crack and noise in apartment buildings. Especially, according to the Apartment Defect Dispute Mediation Committee in Korea (ADDMC) at Ministry of Land Infrastructure and Transport in Korea (MLIT), condensation defects are great importance (14 percent) on whole number of reported cases of faults from 2015 in Korea. Most condensation defects have many different causes that take a toll on the resident's life and space. So it is very important to early detection and repair. For preventing the condensation in apartment buildings, there are building codes in Korea such as 'Standard of Method and Judgment for Apartment defect of investigation, Repair cost Estimate'. This research aims to study on the improvement of preventing the condensation aforementioned korea standard. Types and characteristics (opaque wall, windows, doors) of cause of occurrence and existing state condensation defect is analyzed from evaluation of real application 100 case in 2015 ADDMC data.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2003년도 추계총회 및 학술발표회
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• pp.8-8
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• 2003

• 한국재료학회지
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• 제32권9호
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• pp.396-402
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• 2022

In this study, surface roughness and interfacial defect characteristics were analyzed after forming a high-k oxide film on the surface of a prime wafer and a test wafer, to study the possibility of improving the quality of the test wafer. As a result of checking the roughness, the deviation in the test after raising the oxide film was 0.1 nm, which was twice as large as that of the Prime. As a result of current-voltage analysis, Prime after PMA was 1.07 × 10 A/cm² and Test was 5.61 × 10 A/cm², which was about 5 times lower than Prime. As a result of analyzing the defects inside the oxide film using the capacitance-voltage characteristic, before PMA Prime showed a higher electrical defect of 0.85 × 10¹² cm^-2 in slow state density and 0.41 × 10¹³ cm^-2 in fixed oxide charge. However, after PMA, it was confirmed that Prime had a lower defect of 4.79 × 10¹¹ cm^-2 in slow state density and 1.33 × 10¹² cm^-2 in fixed oxide charge. The above results confirm the difference in surface roughness and defects between the Test and Prime wafer.

• 정보처리학회논문지D
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• 제15D권4호
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• pp.523-530
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• 2008

소프트웨어 개발 시, 생명주기의 프로세스 개선에 저해 요인이 되는 결함이 다수 존재한다. 생명주기의 저해 요인을 제거하고 동시에 체계적으로 이를 관리하기 위하여 본 논문에서는 위험요소의 관리방안을 제안한다. 유사한 프로젝트를 수행 시 영역 전문가의 지식을 활용한 결함요소의 상태전이를 관리하여 발생되는 문제점을 예측, 대비할 수 있게 하여, 소프트웨어 프로세스를 개선할 수 있다. 본 연구에서는 소프트웨어 개발시 발생하는 위험요소 관리에 대한 결함의 전이를 찾아내고, 예방 및 원인을 식별하고자 한다. 또한 이를 정량화 하여 전이단계를 제시한다.

• 한국안전학회지
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• 제38권6호
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• pp.1-8
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• 2023

The health state of the oil transformer is evaluated by the age of use and the state of internal defects. Mineral Oil, used as an insulator for oil transformers, creates specific gases and compounds through chemical reactions caused by heat, moisture, and partial discharge inside the transformer. It is possible to determine the aging and defect of the transformer through these gases and compounds. So, it is an important indicator to evaluate the health of a transformer. In this study, factors for assessing the health of transformers were hierarchically categorized, and key factors for each hierarchy were selected for design weighting. These weights were determined through surveys conducted with experts in the fields of transformer design, operation, and quality. For the health of a transformer, defect-related factors are approximately three times more important than factors related to aging. Additionally, defect-related factors showed a higher weighting for gases generated at high temperatures. Furthermore, Furan was determined to have a high weight, directly associated with insulating paper aging. Based on these findings, a health index was proposed, and a comparative analysis was conducted by categorizing 40 operational transformers into normal and comparison groups to evaluate and validate it.