• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 춘계학술발표대회 논문집
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• pp.167-172
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• 2002

During the operation of military aircraft, maintenance is divided into organizational, intermediate and depot maintenance. In the depot maintenance, after removal of major parts and removable doors, damage assessment is performed. Locating damage, charactering the damage and determining its extent, zoning the damage on the part being repaired and re-evaluation of the damaged area after damage removal. Repair joints are classified by bonded joints and bolted joints, depending on joining material. In this paper, repair method in aging aircraft is investigated and the possibility of application of copmposite patch is surveyed.

• 한국신뢰성학회지:신뢰성응용연구
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• 제2권2호
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• pp.85-97
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• 2002

In this paper, partially repairable concurrent spare parts requirement determination problem of newly procured equipment systems is considered. “partially repairable” means that a portion of damaged parts can be recover their function and reused after repairs. A mathematical model is derived for making an CSP requirement determination subject to the constraint of satisfying any given operational availability limitation. We assume that the failure of a part follows a Poisson process and the repair time has an exponential distribution. Using the generalized Lagrange multipliers method, the solution procedure is derived.

• 박물관보존과학
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• 제7권
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• pp.3-10
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• 2006

경주 은령총에서 출토된 청동제 합은 과거 접합되었다가 파손된 상태로 본체의 경우 전체의 절반 정도만이 남아있어 보존 및 전시를 위해서 보존처리 하였다. 이물질 및 열화된 접착제의 제거 후 재접합 하였는데, 비교적 많은 부분이 남아있는 뚜껑은 복원부위를 쉽게 분리할 수 있는 가역적인 방법으로 처리하였다. 본체의 경우 복원부위가 많기 때문에 유물의 하중을 잘 견딜 수 있도록 에폭시수지를 사용하여 접합하였다. 합을 비파괴 조사한 결과 주조품 이었으며 재질은 Cu-Sn-Pb의 3원계 합금으로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1258-1261
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• 2003

Oil supply system is one of the most important part of Turbine. Lubricating oil of bearings supplied by oil pump. Failure of Oil supply pump critical damaged parts of Turbine, especially bearings. In this paper we have discussed the serious damage of turbine bearings due to failure of Oil supply pump.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.441-444
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• 2007

This paper presents a part of micormechanics-based elastic modeling (Lee and Pyo, 2007) of particle-reinforced composites containing slightly weakened interfaces. The Eshelby's tensor for a damaged ellipsoidal inclusion to model particles with slightly weakened interfaces is incorporated into a micormechanical formulation by Ju and Chen (1994). A damage model in accordance with the Weibull's probabilistic function is also developed to simulate the progression of weakened interface in the composites.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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• pp.109-112
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• 2000

Bitstrems corrupted by channel errors are not only difficult to be decoded but also propagate error to other part of the bitstreams when highly compressed video is transmitted over channels with noise such as mobile communication channels. In this paper, error concealment algorithm performed in decoder is proposed when errors occur for transmission. Proposed algorithm searches moving area with homogeneous movement in neighbored blocks when motion vectors are damaged, then recovers motion vectors of missing blocks considering where missing blocks are belong to. Experiment result shows that proposed algorithm exhibits better performance in PSNR than existing error concealment method.

• 한국산림과학회지
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• 제83권4호
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• pp.450-459
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• 1994

본(本) 연구(硏究)는 최근(最近) 잣나무넓적잎벌의 피해(被害)가 급진적(急進的)으로 확산(擴散)되고있는 경기도(京畿道) 가평군(加平郡)과 강원도(江原道) 홍천군(洪川郡)의 2개(個) 피해임분(被害林分)에 대(對)한 피해해석(被害解析)을 통(通)하여 경제적(經濟的) 피해허용수준(被害許容水準)을 결정(決定)하고 해충(害蟲) 관리(管理)를 위한 종합적(綜合的) 체계수립(體系樹立)의 기초자료(基礎資料)를 얻고자 1984년(年)부터 4개년간(個年間) 실시(實施)하여 다음과 같은 결과(結果)를 얻었다. 1. 임목(林木)의 피해양상(被害樣狀)은 수관(樹冠) 하부(下部) 보다는 상부(上部)에서 심(甚)하게 나타나며 지상부(地上部) 건물질량(乾物質量)의 수직(垂直) 분포(分布)는 건전목(健全木)의 C형(型) 분포(分布)에서 피해(被害)가 증가(增加)할수록 L형(型) 분포화(分布化) 되었다. 2. 잣나무넓적잎벌 피해(被害)로 인(因)한 엽손실(葉損失)은 수고생장(樹高生長)과 직경생장(直徑生長)의 저해(沮害)를 동시(同時)에 일으키며 생장저해(生長沮害)는 엽손실율(葉損失率) 50% 수준(水準)에서 부터 일어나며 이때의 생장감소율(生長減少率)은 10% 내외(內外)였다. 3. 잣나무넓적잎벌 피해(被害)로 인(因)한 직경생장(直徑生長) 감소(減少)는 수관(樹冠) 상부(上部)에서 현저(顯著)하며 하부(下部)로 갈수록 낮은 감소율(減少率)을 보였다. 4. 엽손실(葉損失)에 의한 재적생장(材積生長) 손실(損失)은 피해발생(被害發生) 3년(年) 후(後)인 엽손실율(葉損失率) 50% 범위(範圍)에서 나타났으며 70% 및 90% 피해목(被害木)의 총재적(總材積) 손실율(損失率)은 건전목(健全木)에 비(比)하여 각각(各各) 9%와 20%였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.269-272
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• 1999

It is still hard to measure the strain distribution over entire surface of a medium or large-size stamped part even by using an automated strain measurement system. Several methods which enable to enlarge the measurement range without losing accuracy and precision are suggested in this study, The superposition of images having different high-lightened or damaged part each other results in an enhanced image. A new method for constructing the element connectivity from a line-thinned image makes it possible to identify up to 1,000 elements. And the geometry assembling algorithm is proved very efficient in which the whole area to be measured is divided into several parts ; the coordinate transformation between every two adjacent parts is obtained from the concept of the least square error ; and the 3-D shape or strain distribution over the whole surface is assembled,

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권1호
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• pp.78-83
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• 2005

Currently in Japan, the use of the small wind turbine is an upward trend. There are already many well established small wind turbine generators in use and their various failures have been reported. The most commonly sighted failure is blade damage. Thus the research purpose was set to develop a simple failure diagnostic system, where an Acoustic Emission (AE) signal was produced from the failure part of a blade which was measured by AE sensor. The failure diagnostic technique was thoroughly examined. Concurrently, the damage part of the blade was imitated, the AE signal was measured, and a FFT(Fast Fourier Transform) analysis was carried out, and was compared with the output characteristic. When one sheet of a blade was damaged 40mm or more, the level was computed at which failure could be diagnosed.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.161-162
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• 1998

In this paper, a speech processor which is the most important part of the cochlear implant is developed, to recover auditory ability for the sensorineural disorders who have damaged for their inner ear. This system consists of the analog and digital signal processing part, of which functions is the pre-processing and the main processing, respectively. The main processing is peformed in DSP processor (TMS320C31-40) by using S/W. Because the program is used in this system, it is possible to cope with the individual status of the patients, very easily.