• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.755-762
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• 2000

Entropy coders as a noiseless compression method are widely used as end-point compression for images so there have been many contributions to increase of entropy coder performance and to reduction of entropy coder complexity. In this paper, we propose some entropy coders based on binary forward classification (BFC). BFC requires overhead of classification but there is no change between the amount of input information and that of classified output information, which we prove this property in this paper. And using the proved property, we propose entropy coders which are Golomb-Rice coder after BFC (BFC+GR) and arithmetic coder with BFC(BFC+A). The proposed entropy decoders do not have further complexity Son BFC. Simulation results also show better performance than other entropy coders which have similar complexity to proposed coders.

• Journal of the Korean Society for information Management
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• v.29 no.2
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• pp.205-224
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• 2012

One of the limitations of BOW method is that each term is recognized only by its form, failing to represent the term's meaning or thematic background. To overcome the limitation, different profiles for each term were defined by thematic categories depending on contextual characteristics. In this study, a specific term was used as a classification feature based on its meaning or thematic background through the process of comparing the context in those profiles with the occurrences in an actual document. The experiment was conducted in three phases; term weighting, ensemble classifier implementation, and feature selection. The classification performance was enhanced in all the phases with the ensemble classifier showing the highest performance score. Also, the outcome showed that the proposed method was effective in reducing the performance bias caused by the total number of learning documents.

• The KIPS Transactions:PartB
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• v.14B no.7
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• pp.559-566
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• 2007

Subjective sentences express opinions, emotions, evaluations and other subjective ideas relevant to products or events. These expressions sometimes can be seen in only part of a sentence, thus extracting features from a full-sentence can degrade the performance of subjective-sentence-classification. This paper presents a method for improving the performance of a subjectivity classifier by combining two classifiers generated from the different representations of an input sentence. One representation is a sentimental phrase that represents an automatically identified subjective expression or objective expression and the other representation is a full-sentence. Each representation is used to extract modified n-grams that are composed of a word and its contextual words' polarity information. The best performance, 79.7% accuracy, 2.5% improvement, was obtained when the phrase-level classifier and the sentence-level classifier were merged.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.356-358
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• 2003

DNA microarray기술의 발달로 한꺼번에 수천 개 유전자의 발현 정보를 얻는 것이 가능해졌는데, 이렇게 얻어진 데이터를 효과적으로 분류하는 시스템을 만들어놓으면 새로운 샘플이 정상상태인지, 질병을 가진 상태인지 예측할 수 있다. 분류 시스템을 위하여 여러 가지 특징선택방법들과 분류기법들을 사용할 수 있는데, 모든 상황에서 항상 뛰어난 성능을 보이는 특징선택법이나 분류기를 찾기는 힘들다. 안정되고 개선된 성능을 내기 위해서 특징-분류기의 앙상블을 이용할 수 있는데, 앙상블에 이용될 수 있는 특징선택 방법이나 분류기의 수가 많다면, 앙상블을 만들 수 있는 조합이 많아지기 때문에, 모든 조합에 대하여 앙상블 결과를 구하기는 거의 불가능하다. 이를 해결하기 위하여 본 논문에서는 유전자알고리즘을 이용하여 모든 앙상블 결과를 계산하지 않으면서 최적의 앙상블을 찾아내는 방법을 제안하였으며, 실제로 림프종 암 데이터에 적용한 결과 100%의 결합결과를 보이는 최적의 앙상블을 효과적으로 찾아내었다.

• Journal of KIISE:Software and Applications
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• v.32 no.11
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• pp.1136-1146
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• 2005

Fingerprint classification is useful in an automated fingerprint identification system (AFIS) to reduce the matching time by categorizing fingerprints. Based on Henry system that classifies fingerprints into S classes, various techniques such as neural networks and support vector machines (SVMs) have been widely used to classify fingerprints. Especially, SVMs of high classification performance have been actively investigated. Since the SVM is binary classifier, we propose a novel classifier-combination model, multiple decision templates (MuDTs), to classily fingerprints. The method extracts several clusters of different characteristics from samples of a class and constructs a suitable combination model to overcome the restriction of the single model, which may be subject to the ambiguous images. With the experimental results of the proposed on the FingerCodes extracted from NIST Database4 for the five-class and four-class problems, we have achieved a classification accuracy of $90.4\%\;and\;94.9\%\;with\;1.8\%$ rejection, respectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.641-647
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• 2009

In this paper, a new filtering scheme for adaptive cruise control (ACC) system is presented. In the proposed scheme, the identification of the mode of the preceding vehicle is considered as a classification problem and it is done by a neural network classifier. The neural network classifier outputs a posterior probability of the mode of the preceding vehicle and the probability is directly used in the IMM framework. Finally, ten scenarios are made and the proposed NIMM is tested on them to show its validity.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04b
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• pp.796-798
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• 2004

기존의 번호판 인식 시스템에서는 대부분 카메라가 고정 상태에서 차량의 전면부를 찍어 영상을 획득하고, 이로부터 번호판을 추출하고 인식한다 그러나 본 연구에서는 기존 연구들과 달리 이동 중인 자동차에 카메라를 설치하여 움직이는 자동차의 영상을 획득하여 번호판을 추출하고 인식한다. 인식하고자 하는 영상이 잡음이나 왜곡 없이 깨끗하다면 인식 과정은 간단하게 수행될 것이다. 그러나, 실제로 얻어진 영상은 간단한 방법으로 인식하기에는 어려올 정도로 왜곡이나 변형이 심한 경우가 많다. 따라서 본 논문에서는 SVM 전단에 모듈라 신경망을 결합하여 인식하는 방법을 사용함으로써 잡음과 같은 변형에 덜 민감하도록 하고자 하였다. 실험결과, 제안하는 분류기를 이용한 방법이 번호판 인식에 우수한 성능을 보임을 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1551-1554
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• 2011

대용량 데이터 환경에의 적용이 가능한 대용량 학습기반의 자동범주화 기법과 범용적으로 사용할 수 있는 기법은 대량의 정보를 처리해야하는 정보분석 및 정보서비스 환경에 가장 필요한 기술요소라 할 수 있다. 본 논문에서는 대용량의 문서를 단위 컴포넌트로 분할하여 학습하고 이를 동적으로 결합하는 대용량 분류기 생성 기법을 소개하고 자동범주화 성능을 SVM 모델과 비교하여 봄으로써, 본 기술의 활용 가능성을 살펴보도록 한다.

• Journal of KIISE:Software and Applications
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• v.34 no.9
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• pp.857-868
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• 2007

The good classifier ensemble should have a high complementarity among classifiers in order to produce a high recognition rate and its size is small in order to be efficient. This paper proposes a classifier ensemble selection algorithm with coarse-to-fine stages. for the algorithm to be successful, the original classifier pool should be sufficiently diverse. This paper produces a large classifier pool by combining several different classification algorithms and lots of feature subsets. The aim of the coarse selection is to reduce the size of classifier pool with little sacrifice of recognition performance. The fine selection finds near-optimal ensemble using genetic algorithms. A hybrid genetic algorithm with improved searching capability is also proposed. The experimentation uses the worldwide handwritten numeral databases. The results showed that the proposed algorithm is superior to the conventional ones.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.138-140
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• 1999

분류기법은 과거데이터를 분석하여 새로운 데이터에 대한 예측에 사용되며, 결정트리 알고리즘을 많이 사용한다. 따라서, 이 기법은 전자상거래에서 DB 마케팅을 위해 데이터베이스에 저장되어 있는 고객데이터를 분석하여 암시적인 고객들의 행위규칙을 찾고, 예측하기 위하여 사용할 수 있다. 기존의 분류알고리즘들은 전자상거래에서 일반적인 연속형 고객데이터를 처리하는데는 많은 문제점을 가지고 있다. 이러한 문제를 해결하기 위하여 연속형 데이터를 범주형 데이터로 변환하는 알고리즘을 구현하였다. 이 논문은 전자상거래에 적용하기 위한 고객분류기로서 ID3 알고리즘에 1차원 클러스터링알고리즘을 결합하여 사용한다.