• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.345-350
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• 2002

In this study, researchers classifying the artificial flaws in semiconductor packages are performed by pattern recognition technology. For this purposes, image pattern recognition package including the user made software was developed and total procedure including ultrasonic image acquisition, equalization filtration, binary process, edge detection and classifier design is treated by Backpropagation Neural Network. Specially, it is compared with various weights of Backpropagation Neural Network and it is compared with threshold level of edge detection in preprocessing method fur entrance into Multi-Layer Perceptron(Backpropagation Neural network). Also, the pattern recognition techniques is applied to the classification problem of defects in semiconductor packages as normal, crack, delamination. According to this results, it is possible to acquire the recognition rate of 100% for Backpropagation Neural Network.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.721-726
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• 2005

In this study, researchers classifying the artificial flaws in semiconductor. packages are performed by pattern recognition technology. For this purposes, image pattern recognition package including the user made software was developed and total procedure including ultrasonic image acquisition, equalization filtration, binary process, edge detection and classifier design is treated by Backpropagation Neural Network. Specially, it is compared with various weights of Backpropagation Neural Network and it is compared with threshold level of edge detection in preprocessing method for entrance into Multi-Layer Perceptron(Backpropagation Neural network). Also, the pattern recognition techniques is applied to the classification problem of defects in semiconductor packages as normal, crack, delamination. According to this results, it is possible to acquire the recognition rate of 100% for Backpropagation Neural Network.

• 제어로봇시스템학회논문지
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• 제9권2호
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• pp.131-139
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• 2003

Shape descriptors play an important role in systems for object recognition, retrieval, registration, and analysis. Seven well-known descriptors including MPEG-7 visual descriptors arebriefly reviewed and a new robust pattern recognition descriptor is proposed. Performance comparison among descriptors are presented. Experiments show that the newly proposed descriptor yields better performance results than Fourier, invariant moment, and edge histogram descriptors.

• 전자공학회논문지
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• 제52권7호
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• pp.86-92
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• 2015

본 논문에서는 지역적인 에지의 방향 정보와 반응 크기, 주변 화소와의 밝기값 차이를 LDP 코드에 포함함으로써 얼굴 표정 인식률을 향상시킨다. 기존 LDP 코드를 사용하면 LBP에 비해서 영상의 밝기 변화에 덜 민감하고 잡음에 강한 장점을 가진다. 하지만, 밝기 변화가 없는 매끄러운 영역의 정보를 표현하기 어렵고, 배경에 얼굴과 유사한 에지 패턴이 존재하는 경우에는 인식률이 저하되는 문제점이 있다. 따라서 에지 방향 정보를 기반으로 에지 강도 및 밝기값을 추가할 수 있도록 LDP 코드를 개선하고, 인식률을 측정한다.

• 디지털콘텐츠학회 논문지
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• 제13권2호
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• pp.189-195
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• 2012

본 논문에서는 휴먼 인지를 위한, 근적외선 얼굴 영상에서의 얼굴 검출 방법이 제안된다. 에지의 강도와 방향에 기반한 에지 히스토그램이 근적외선 영상으로부터 얼굴을 검출하기 위해 사용되었다. 조명변화에 강인하기 때문에, 제안된 에지 히스토그램은 얼굴을 효과적으로 표현하고 구별한다. 얼굴 검출을 위한 분류기로서는 SVM(Support Vector Machine)을 사용하였으며 제안한 방법은 ULBP(Uniform Local Binary Pattern)보다 적은 피쳐 개수를 가지면서도 에러율 측면에서, ULBP의 경우보다 나은 성능을 나타내었다.

• International Journal of Precision Engineering and Manufacturing
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• 제5권3호
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• pp.11-18
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• 2004

In this paper, the classification of artificial defects in semiconductor packages is studied by using pattern recognition technology. For this purpose, the pattern recognition algorithm includes the user made MATLAB code. And preprocess is made of the image process and self-organizing map, which is the input of the back-propagation neural network and the dimensionality reduction method, The image process steps are data acquisition, equalization, binary and edge detection. Image process and self-organizing map are compared to the preprocess method. Also the pattern recognition technology is applied to classify two kinds of defects in semiconductor packages: cracks and delaminations.

• 한국정밀공학회지
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• 제5권4호
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• pp.32-38
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• 1988

Apaptive cintrol of machine tool is aimed to change cutting state satis- factorily without aid of a machine operator, if the cuting state is abnomal such as formation of tangled ribbon type chip, built-up edge and generation of chattering and so on. Among these the recognition of chip type is one of the most important since it has imlications relate to : 1. Safety of operator 2. Stoppage of work due to entanglment in tool and workpiece of chip 3. Problem of producted chip control In this paper the chip type is discriminatied by the pattern recognition technique. It is found that the power spectrum of cutting force for each chip type has it's own special pattern. Linear discriminant function for the recognition of the chip type is obtained by learning process. The discriminant function can be the basis of adaptive control for the rate of success of recognition by pattern recognition technique is at leasthigher than 83%.

• ETRI Journal
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• 제32권5호
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• pp.784-794
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• 2010

Automatic facial expression recognition has many potential applications in different areas of human computer interaction. However, they are not yet fully realized due to the lack of an effective facial feature descriptor. In this paper, we present a new appearance-based feature descriptor, the local directional pattern (LDP), to represent facial geometry and analyze its performance in expression recognition. An LDP feature is obtained by computing the edge response values in 8 directions at each pixel and encoding them into an 8 bit binary number using the relative strength of these edge responses. The LDP descriptor, a distribution of LDP codes within an image or image patch, is used to describe each expression image. The effectiveness of dimensionality reduction techniques, such as principal component analysis and AdaBoost, is also analyzed in terms of computational cost saving and classification accuracy. Two well-known machine learning methods, template matching and support vector machine, are used for classification using the Cohn-Kanade and Japanese female facial expression databases. Better classification accuracy shows the superiority of LDP descriptor against other appearance-based feature descriptors.

• 한국통신학회논문지
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• 제14권4호
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• pp.398-404
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• 1989

광굴절 효과를 갖는 $BaTiO_2$단결정에서의 실시간 홀로그램을 이용한 광패턴인식 시스템을 해석하고 실험하였다. 시스템의 패턴 판별능력을 높이기 위해 edge enhancement 기법을 도입하였으며, 주파수 평면 상관기 구조로 구성된 시스템은 5.5mW의 저출력 광원으로도 8sec 이내에 패턴인식이 가능하였다.

• 정보처리학회논문지B
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• 제13B권3호
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• pp.315-322
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• 2006

개미 군락 시스템(Ant Colony System, ACS)은 조합 최적화 문제 중의 하나인 방문 판매원 문제에(Traveling Salesman Problem, TSP) 간단하게 응용할 수 있고 좋은 결과를 보여주었으며 최근에는 영상처리 분야의 패턴 인식, 영상 추출, 에지 검색 등에 응용되고 있다. 에지 검색은 검색된 에지를 이용하여 문서 분류, 문자 인식, 얼굴 인식 등과 같은 분야에서 다양하게 응용될 수 있다. 기존의 연산자 위주의 에지 검색 기법들은 에지를 명확하게 검색한다고 해도 이 검색 결과를 이용하여 다음 단계의 영상처리를 위해서는 그 목적에 맞도록 새로운 후처리 작업을 거쳐야 한다는 단점이 있다. 본 연구에서는 개미 군락 시스템의 특성을 이용하여 에지의 명확한 검색뿐 아니라, 좀 더 안정적이고(robustness) 유연성을(flexibility) 갖는 에지 검색 기법을 제안하며 실제 디지털 영상에 적용하였을 때 만족할 만한 결과를 얻을 수 있었다.