• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.144-147
• /
• 1999

The objective of this study is to quantitatively evaluate the effects of various SAR speckle reduction methods for multisource land-cover classification by backpropagation neural network, especially over the coastal region. The land-cover classification using neural network has an advantage over conventional statistical approaches in that it is distribution-free and no prior knowledge of the statistical distributions of the classes is needed. The goal of multisource land-cover classification acquired by different sensors is to reduce the classification error, and consequently SAR can be utilized an complementary tool to optical sensors. SAR speckle is, however, an serious limiting factor when it is exploited for land-cover classification. In order to reduce this problem. we test various speckle methods including Frost, Median, Kuan and EPOS. Interpreting the weights about training pixel samples, the “Importance Value” of each SAR images that reduced speckle can be estimated based on its contribution to the classification. In this study, the “Importance Value” is used as a criterion of the effectiveness.

• 산업경영시스템학회지
• /
• 제33권4호
• /
• pp.69-78
• /
• 2010

Multi-criteria ABC inventory classification is one of the most widely employed techniques for efficient inventory control, and it considers more than one criterion for categorizing inventory items into groups of different importance. Recently, Ramanathan (2006) proposed a weighted linear optimization (WLO) model for the problem of multi-criteria ABC inventory classification. The WLO model generates a set of criteria weights for each item and assigns a normalized score to each item for ABC analysis. Although the WLO model is considered to have many advantages, it has a limitation that many items can share the same optimal efficiency score. This limitation can hinder a precise classification of inventory items. To overcome this deficiency, we propose a context-dependent DEA based method for multi-criteria ABC inventory classification problems. In the proposed model, items are first stratified into several efficiency levels, and then the relative attractiveness of each item is measured with respect to less efficient ones. Based on this attractiveness measure, items can be further discriminated in terms of their importance. By a comparative study between the proposed model and the WLO model, we argue that the proposed model can provide a more reasonable and accurate classification of inventory items.

• Communications for Statistical Applications and Methods
• /
• 제20권4호
• /
• pp.271-281
• /
• 2013

This paper considers a problem of classification of variable stars based on functional data analysis. For a better understanding of galaxy structure and stellar evolution, various approaches for classification of variable stars have been studied. Several features that explain the characteristics of variable stars (such as color index, amplitude, period, and Fourier coefficients) were usually used to classify variable stars. Excluding other factors but focusing only on the curve shapes of variable stars, Deb and Singh (2009) proposed a classification procedure using multivariate principal component analysis. However, this approach is limited to accommodate some features of the light curve data that are unequally spaced in the phase domain and have some functional properties. In this paper, we propose a light curve estimation method that is suitable for functional data analysis, and provide a classification procedure for variable stars that combined the features of a light curve with existing functional data analysis methods. To evaluate its practical applicability, we apply the proposed classification procedure to the data sets of variable stars from the project STellar Astrophysics and Research on Exoplanets (STARE).

• 정보관리연구
• /
• 제35권3호
• /
• pp.109-123
• /
• 2004

과학기술정보의 의미적 상호운용성 문제는 빈번하게 발생한다. 잘 만들어진 분류체계는 상이한 데이터베이스 간에 의미상 불일치 없이 정보를 교환하기 위한 도구로 사용될 것이다. 하지만 각 데이터베이스가 취하고 있는 분류체계가 상이함으로 인해서 여전히 현실적인 장벽이 존재한다. 따라서 분류체계간의 일치 및 조화는 매우 시급한 문제이다. 본 논문의 목표는 다른 분류체계('국가과학기술표준분류'와 'KISTI 표준 분류')를 갖는 데이터베이스간의 정보 교환 시에 발생할 수 있는 의미적 불일치를 해결하는 것이다. 이를 위해서 과학기술의 개념적 체계 분석을 수행하였고 다섯가지의 일치/불일치 유형을 사례에 기반하여 분석하였다.

• 환경영향평가
• /
• 제18권6호
• /
• pp.387-392
• /
• 2009

As Our society's environmental awareness and concern the significant increases, the importance of the legal system for environmental conservation such as the Prior Environmental Review System, Environmental Impact Assessment is growing increasingly. but, still critical issues are present such as reliability. Though there could be various causes such as the system or procedures etc. Above all, basically the environmental data problem is the critical cause. Therefore, this study was trying to improve the environmental data accuracy using the high-resolution color aerial photography, LiDAR data and Object Oriented Classification method. And in this study, classification based on coverage percentage of a particular species was attempted through the multi-resolution segmentation and multi-level classification method. The classification result was verified by comparison with 11 points local survey data. All 11 points were classified correctly. And even though the exact coverage percentage of the particular species did not be measured, It was confirmed that the species was occupied similar portion. It is important that the environmental data which can be used for the conservation value assessment could be acquired.

• 한국문헌정보학회지
• /
• 제42권4호
• /
• pp.291-310
• /
• 2008

미국 의회도서관이 독도(Tok Island)에 관한 주제어를 리앙쿠르 록스(Liancourt Rocks)로 변경추진에 따른 논란을 계기로 독도의 일반적인 현황과 표기 문제 및 국제적으로 사용되고 있는 표기 현황을 검토하였다. 이 검토를 바탕으로 문헌정보학 자료조직 분야에서 KDC, LCC, NDC의 독도표기 현황을 비교, 분석하고 향후 도서관계의 역할을 모색해보고자 하였다.

• 스마트미디어저널
• /
• 제9권4호
• /
• pp.17-25
• /
• 2020

In the image object classification problem, low-resolution images may have a negative impact on the classification result, especially when the classification method, such as a convolutional neural network (CNN) model, is trained on a high-resolution (HR) image dataset. In this paper, we analyze the behavior of applying a classical super-resolution (SR) method such as bicubic interpolation, and a deep CNN model such as SRCNN to enhance low-resolution (LR) weeds images used for classification. Using an HR dataset, we first train a CNN model for weeds image classification with a default input size of 128 × 128. Then, given an LR weeds image, we rescale to default input size by applying the bicubic interpolation or the SRCNN model. We analyze these two approaches on the Chonnam National University (CNU) weeds dataset and find that SRCNN is suitable for the image size is smaller than 80 × 80, while bicubic interpolation is convenient for a larger image.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2022년도 춘계학술대회
• /
• pp.444-447
• /
• 2022

최근 몇 년 동안 더 깊은 신경망 아키텍처로 인해 컴퓨터 비전 이미지 분류 작업이 더 빠르고 더 좋아졌다. 그러나 대부분의 이미지 분류 작업은 특정 이미지 모양(예: 고양이와 개 구별)을 기반으로 분류하도록 설계되었지만 낮과 밤 또는 사계절과 같은 기간을 구별하도록 훈련된 분류 모델은 많지 않다. 같은 장소의 사계절 이미지를 구분하기 위한 선행 연구는 있는 반면 일반 영상의 계절 분류 연구는 현재 부재한 실정이다. 그래서 본 논문에서는 일반 영상의 계절 분류 문제에 대한 다양한 접근 방식을 제시한다. 간단한 특징 추출부터 합성곱 신경망 구축, 전이 학습에 이르기까지 계절별 이미지 분류를 위한 세 가지 방법을 연구하고 정확도 결과를 비교, 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제17권6호
• /
• pp.1743-1758
• /
• 2023

Automatic modulation classification is a critical algorithm for non-cooperative communication systems. This paper addresses the challenging problem of closed-set and open-set signal modulation classification in complex channels. We propose a novel approach that incorporates a self-learning filter and center-loss in Deep Residual Shrinking Networks (DRSN) for closed-set modulation classification, and the Opendistance method for open-set modulation classification. Our approach achieves better performance than existing methods in both closed-set and open-set recognition. In closed-set recognition, the self-learning filter and center-loss combination improves recognition performance, with a maximum accuracy of over 92.18%. In open-set recognition, the use of a self-learning filter and center-loss provide an effective feature vector for open-set recognition, and the Opendistance method outperforms SoftMax and OpenMax in F1 scores and mean average accuracy under high openness. Overall, our proposed approach demonstrates promising results for automatic modulation classification, providing better performance in non-cooperative communication systems.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제35권1호
• /
• pp.41-49
• /
• 2008

지문분류는 지문을 전역특징에 따라 미리 정의된 클래스로 분류하여 대규모 지문식별시스템의 매칭시간을 감소시키는데 유용하다. 그런데, 지문의 고유성으로 인해 전역특징이 다양하게 분포함에도 불구하고, 기존의 지문분류 방법들은 모든 지문에 대해 고정된 영역으로부터 비적응적으로 전역특징을 추출하였다. 본 논문에서는 다양한 지문을 효과적으로 분류하기 위해 각 지문에 적응적으로 특징을 추출하는 방법을 제안한다. 이는 각 지문의 융선 방향의 변화량을 계산하여 적응적으로 특징영역을 탐색한 후, 특징영역내의 융선 방향 값을 특징벡터로 추출하고 지지벡터기계(Support Vector Machines)를 이용해 분류한다. 본 논문에서는 NIST4 데이타베이스를 이용하여 실험을 수행하였다. 그 결과 5클래스 분류에 대해 90.3%, 4클래스 분류에 대해 93.7%의 분류성능을 얻었으며, 비적응적으로 추출한 특징벡터와의 비교실험을 통해 제안하는 적응적 특징추출방법의 유용성을 입증하였다.