• Proceedings of the Materials Research Society of Korea Conference
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• 1999.11a
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• pp.100-100
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• 1999

• Journal of Korea Multimedia Society
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• v.15 no.4
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• pp.439-448
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• 2012

TFT-LCD panel images have non-uniform brightness, noise signal and defect signal. It is hard to divide defect signal because of non-uniform brightness and noise signal, so various divide methods have being developed. In this paper, we suggest method to divide defective regions on TFT-LCD panel image by estimating a menas of two different size of windows, which is suggested by Eikvil et al., and using difference of them. But in this method, the size of detectable defects is restricted by the size of window, hence it has inefficient problem that the size of window have to increase to divide a large defect region. To solve this problem we suggest an algorithm which can divide various size of defects, by using Multi-scale and restrict a detectable size of defects in each scale. To prove an efficiency of suggested algorithm, we show that resulting images of real TFT-LCD panel images and an artificial image with various defects.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.94-101
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• 2007

In the Hard Disk Drive(HDD) production, the detect pattern or defective HDD set is important information to diagnosis of defective HDD set. This paper proposes a pattern recognition neural network for the defect distribution of HDD. In this paper, 5 characteristics are determined for the classification to six standard defect pattern classes. A multi-layer perceptron is trained for the pattern classification the inputs of which are 5 characteristic values and the 6 outputs are the nodes of standard patterns. The experiment with proposed neural network shows satisfactory results.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.271-273
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• 2013

본 논문에서는 비파괴 검사를 통하여 얻은 세라믹 영상에 퍼지 기법과 ART2 기법을 적용하여 결함을 검출하는 방법을 제안한다. 제안된 방법은 세라믹 소재로 얻어진 영상에서 결함의 구간을 설정하기 위해 퍼지 스트레칭 기법을 적용하여 명암도를 대비시킨다. 명암 대비가 강조된 영상에서 퍼지 이진화 기법을 적용한 후, 상/하 경계선에 가장 많이 분포된 곳을 Max, Min으로 설정하고, Max+20, Min-20을 결함 구간으로 설정한다. 설정한 결함 구간 내의 비파괴 세라믹 영상에서 ART2 알고리즘 기법을 적용하여 세라믹 영상의 결함을 검출한다. 본 논문에서 제안된 방법을 비파괴 세라믹 영상을 대상으로 실험한 결과, 제안된 방법이 기존의 세라믹 결함 검출 방법보다 비파괴 세라믹 영상에서 다양한 형태의 결함이 검출되는 것을 확인하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.107-117
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• 2016

STD method using a mean and standard deviation is widely used in various inspection systems. The result of detection using the STD method is very dependent on the threshold value. This paper proposes an adaptive defect detection algorithm to with a precise detection of an ultimate defect. The proposed method is determined threshold value adaptively using a skewness that indicates a similarity of intensity and normal distribution of image. In the experiment, we used a various TFT-LCD images for a quantitative evaluation of defect detection performance evaluation result to prove the performance of the proposed algorithm.

• Composites Research
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• v.37 no.3
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• pp.179-185
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• 2024

This study quantitatively evaluated and investigated the changes in transverse tensile strength of unidirectional fiber-reinforced composites with initial void defects using a Representative Volume Element (RVE) model. After calculating the appropriate sample size based on margin of error and confidence level for initial void defects, a sample group of 5000 RVE models with initial void defects was generated. Dimensional reduction and density-based clustering analysis were conducted on the sample group to assess similarity, confirming and verifying that the sample group was unbiased. The validated sample analysis results were represented using a Weibull distribution, allowing them to be applied to the reliability analysis of composite structures.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.9-16
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• 1999

We have investigated effects of local damage accumulation for ultra-low energy As and B ion implant using highly efficient molecular dynamics(MD) scheme. We simulated ion implantation by MD simulation using recoil ion approximation (RIA) method and local cell damage accumulation (LCDA) model proposed in the paper. Local damage accumulation probability function consisted of deposited energy in a unit cell, implant dose rate, target material, projectile atom, and recoil event number. The simulated results were good agreement with the experimental and other simulated results. The MDRANGE results without damage accumulation were different from SIMS data in the tail region. We also simulated 2 dimensional dopant and damage profiles using the local damage accumulation model and recoil ion approximation method.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.532-537
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• 2004

FEF(Focused Electromagnetic Field) technique was newly developed that is based on the induction principle exciting electromagnetic field. The technique consists of an induction wire and a sensor for detecting electromagnetic field, and is applied in a non-contact mode. In this study, the technique was applied to the evaluation of EDM slits in some conductive materials - aluminum alloy, stainless steel and Inconel alloy. The voltage in the non-defect region is depended upon the measurement lift-off. The voltage signals on defects are measured with peak values, and the peak values changed with the depth of defects. The voltage distributions for all conductive materials are the same trend.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.326-329
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• 2010

항공기는 전체 수명동안 무수한 반복하중에 노출되기 때문에, 동체에 피로로 인한 다중균열이 불가피하게 발생하게 된다. 이 다중균열은 기체의 강성을 저하시킬 뿐 만 아니라, 종국적으로는 해당 기체구조의 파단을 야기할 수 있다. 초기 결함과 운용 중에 작용되는 응력 스펙트럼은 구조물의 피로수명에 영향을 끼치며 고려해야 한다. 본 논문에서는 초기결함 특성을 파악하기 위한 등가초기결함크기 분포를 산출하고 리벳 시편의 다중균열모델에 대해서 초기결함과 응력배열을 고려한 해석을 수행하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.397-400
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• 2001

본 논문에서는 운전 단계중의 상용소프트웨어 성장활용을 설명한 수 있고 또 현장 고장 데이타로부터 활용성장을 예측하는데 관계되는 인자를 결합할 수 있는 새로운 모델을 개발한다. 이 모델은 상용 소프트웨어의 실제 황용이 시간의 멱수 함수로 나타난다는 가정으로부터 생기는 웨이블 분포에 근거한다. 선형신뢰도모델은 잔여결함의 평균크기와 작업량이 일정하고 겉보기 결함밀도가 실제 결함밀도와 동일하다는 가정 하에 유도된다. 기하학적모델은 결함을 수정함에 따라 평균결합크기가 기하학적으로 감소한다는 가정에 있어서 파이가 있다. 한편, Rayleigh모델은 잔여 결함의 평균크기가 시간에 따라 선형적으로 감소한다는 가정에 있어서 차이가 있다. 본 논문에서는 소프트웨어의 신뢰도 요인의 거동을 가정하여 이러한 다양성을 수용하기 위한 모델링을 하였다.