• 전자공학회논문지
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• 제53권3호
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• pp.59-66
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• 2016

이 논문에서는 비유사도-기반 분류(dissimilarity-based classifications: DBC)를 효율적으로 수행할 수 있는 차원 축소 방법들을 비교 평가한 실험 결과를 보고한다. DBC에선 분류를 위해 대상 물체를 측정한 결과 값들(특징 요소들의 집합)을 이용하는 대신에 각 대상 물체들 사이의 비유사도를 측정하여 분류한다. 현재 DBC와 관련된 이슈들 중의 하나는 대규모 데이터를 취급할 경우에 비유사도 공간의 차원이 고차원으로 되는 문제가 있다. 이 문제를 해결하기 위하여 현재 프로토타입 선택(prototype selection: PS)방법이나 차원 축소(dimension reduction: DR)방법을 이용하고 있다. PS는 전체 학습 데이터에서 프로토타입을 추출하여 비유사도 공간을 구성하는 방법이고, DR은 전체 학습 데이터로 먼저 비유사도 공간을 구성한 다음 이 공간의 차원을 축소하는 방법이다. 이 논문에서는 PS이나 DR 대신에, 학습 데이터에 대한 주성분 분석으로 적절한 차원의 고유 공간 (Eigen space: ES)을 구성한 다음, 이 고유 공간으로 매핑 된 벡터들 사이의 $l_p$-놈(norm) 거리를 비유사도 거리로 측정하여 이용하는 DBC를 제안한다. 인터넷에 공개된 인공 및 실세계 데이터를 이용하여 최 근방 이웃 분류규칙으로 ES에서 수행한 DBC의 분류 성능을 측정한 결과, 고유공간의 차원을 적절하게 선정하였을 경우 PS와 DR를 이용한 DBC보다 분류 성능이 더 향상되었음을 확인하였다.

• 대한음성학회지:말소리
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• 제52호
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• pp.145-160
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• 2004

In this paper, a new noise compensation method based on the eigenvoice framework in feature space is proposed to reduce the mismatch between training and testing environments. The difference between clean and noisy environments is represented by the linear combination of K eigenvectors that represent the variation among environments. In the proposed method, the performance improvement of speech recognition systems is largely affected by how to construct the noisy models and the bias vector set. In this paper, two methods, the one based on MAP adaptation method and the other using stereo DB, are proposed to construct the noisy models. In experiments using Aurora 2 DB, we obtained 44.86% relative improvement with eigen-environment method in comparison with baseline system. Especially, in clean condition training mode, our proposed method yielded 66.74% relative improvement, which is better performance than several methods previously proposed in Aurora project.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제12권3호
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• pp.250-255
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• 2012

Face recognition has wide applications in security and surveillance systems as well as in robot vision and machine interfaces. Conventional challenges in face recognition include pose, illumination, and expression, and face recognition at a distance involves additional challenges because long-distance images are often degraded due to poor focusing and motion blurring. This study investigates the effectiveness of applying photon-counting linear discriminant analysis (Pc-LDA) to face recognition in harsh environments. A related technique, Fisher linear discriminant analysis, has been found to be optimal, but it often suffers from the singularity problem because the number of available training images is generally much smaller than the number of pixels. Pc-LDA, on the other hand, realizes the Fisher criterion in high-dimensional space without any dimensionality reduction. Therefore, it provides more invariant solutions to image recognition under distortion and degradation. Two decision rules are employed: one is based on Euclidean distance; the other, on normalized correlation. In the experiments, the asymptotic equivalence of the photon-counting method to the Fisher method is verified with simulated data. Degraded facial images are employed to demonstrate the robustness of the photon-counting classifier in harsh environments. Four types of blurring point spread functions are applied to the test images in order to simulate long-distance acquisition. The results are compared with those of conventional Eigen face and Fisher face methods. The results indicate that Pc-LDA is better than conventional facial recognition techniques.

• 한국정보과학회논문지:소프트웨어및응용
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• 제27권5호
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• pp.463-472
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• 2000

본 논문에서는 연상 메모리 기능을 수행하는 셀룰라 신경망(Cellular Neural Network)의 설계를 위한 새로운 방법론을 제안한다. 먼저, 셀룰라 신경망 모델의 기본적 특성들을 소개한 후, 최적 성능을 가지고 이진 원형 패턴들을 저장할 수 있는 셀룰라 신경망 모델의 설계 방법을 제약 조건이 가해진 최적화 문제로 공식화한다. 다음으로 이 문제의 제약 조건을 선형 행렬 부등식(Linear Matrix Inequalities)을 포함하는 부등식의 형태로 변환시킬 수 있음을 관찰한다. 마지막으로 셀룰라 신경망 최적 설계 문제를 내부점 방법(interior point method)에 의해 효율적으로 풀릴 수 있는 일반화된 고유값 문제(Genaralized EigenValue Problem)로 변환한다. 본 논문에서 제시하는 셀룰라 신경망 설계 방법론은 공간 변형 형판 셀룰라 신경망과 공간 불변 형판 셀룰라 신경망 설계에 모두 적용될 수 있다. 설계 예제를 통해 제안된 방법의 유효성을 검증한다.

• 한국학교ㆍ지역보건교육학회지
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• 제7권
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• pp.1-17
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• 2006

Background: School is a primary health education setting for adolescents and the continuous support should be provided to renew school health education curriculum correspondent to cultural changes in Korean society. Objectives: This study was conducted to identify the principals and teachers' health education needs for their students and to analyze their conceptual map for health education curriculum at school. Methods: The sample size of the preliminary study was 321 of the teachers in elementary, middle, and high school, and that of the main study was 355 middle school principals and teachers over the country. The self-administered mailing survey was conducted to collect the available health education topics in the preliminary study, to identify the factor structure of the health education topics and to analyze the conceptual properties on health education with exploratory factor analysis and multidimensional scaling analysis in SPSS 12.0. Results: A total of 21 health education topics were collected from the preliminary survey and 31 topics were, comprehensively, generated for the main survey. In exploratory factor analysis, seven factors were generated in 1.0 or greater Eigen value standard. The seven factors were 'life health promotion,' 'disease prevention and drug control,' 'bulling and aggression prevention,' 'injury and sexual harassment prevention,' human-efficacy and regulation,' 'health protection for adolescence,' and 'alcohol and tobacco control.' The educational need scores were the highest in 'human-efficacy and regulation' and 'injury and sexual harassment prevention.' The two-dimensional cooperates were generated for the 31 health education topics and the two dimensional properties which divided the conceptual space were 'health-safety' for one and 'public/environmental-individual/personal' for the other. That is, middle school principals and teachers primarily, understand the health education curriculum in the sense of 'health vs. safety' and 'public/environmental vs individual/personal.' Conclusions: Health education curriculum and textbook should be developed based on teachers' needs and conditions for health education in school fields. The field-based health education programs or textbook would make more possible problem-solving health education for youth in real school fields.