• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.285-288
• /
• 2008

In many intrusion detection applications, n-gram approach has been widely applied. However, n-gram approach has shown a few problems including double counting of features. To address those problems, we applied n-gram augmented Naive Bayes directly to classify intrusive sequences and compared performance with those of Naive Bayes and Support Vector Machines (SVM) with n-gram features by the experiments on host-based intrusion detection benchmark data sets. Experimental results on the University of New Mexico (UNM) benchmark data sets show that the n-gram augmented method, which solves the problem of independence violation that happens when n-gram features are directly applied to Naive Bayes (i.e. Naive Bayes with n-gram features), yields intrusion detectors with higher accuracy than those from Naive Bayes with n-gram features and shows comparable accuracy to those from SVM with n-gram features.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.208-209
• /
• 2011

In this paper, we introduce a Naive Bayes learning algorithm for learning and reasoning in Map-Reduce model based environment. For this purpose, we use Apache Mahout to execute Distributed Naive Bayes on University of California, Irvine (UCI) benchmark data sets. From the experimental results, we see that Apache Mahout' s Distributed Naive Bayes algorithm is comparable to WEKA' s Naive Bayes algorithm in terms of performance. These results indicates that in the future Big Data environment, Map-Reduce model based systems such as Apache Mahout can be promising for machine learning usage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.201-203
• /
• 2011

We report an experimental result of applying a data mining algorithm for analyzing the questionnaire results of high school students' views on science-technology-society (HS-VOSTS). The preliminary empirical result of Naive Bayes classifier on HS-VOSTS questionnaire from one South Korean university students indicates that data mining algorithms can be effectively applied to automated knowledge discovery from students' survey data.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.4
• /
• pp.805-812
• /
• 2009

In many intrusion detection applications, n-gram approach has been widely applied. However, n-gram approach has shown a few problems including unscalability and double counting of features. To address those problems, we applied n-gram augmented Naive Bayes with k-truncated suffix tree (k-TST) storage mechanism directly to classify intrusive sequences and compared performance with those of Naive Bayes and Support Vector Machines (SVM) with n-gram features by the experiments on host-based intrusion detection benchmark data sets. Experimental results on the University of New Mexico (UNM) benchmark data sets show that the n-gram augmented method, which solves the problem of independence violation that happens when n-gram features are directly applied to Naive Bayes (i.e. Naive Bayes with n-gram features), yields intrusion detectors with higher accuracy than those from Naive Bayes with n-gram features and shows comparable accuracy to those from SVM with n-gram features. For the scalable and efficient counting of n-gram features, we use k-truncated suffix tree mechanism for storing n-gram features. With the k-truncated suffix tree storage mechanism, we tested the performance of the classifiers up to 20-gram, which illustrates the scalability and accuracy of n-gram augmented Naive Bayes with k-truncated suffix tree storage mechanism.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.406-409
• /
• 2008

We consider the problem of exploiting a taxonomy of propositionalized attributes in order to learn compact and robust classifiers. We introduce Propositionalized Attribute Taxonomy guided Naive Bayes Learner (PAT-NBL), an inductive learning algorithm that exploits a taxonomy of propositionalized attributes as prior knowledge to generate compact and accurate classifiers. PAT-NBL uses top-down and bottom-up search to find a locally optimal cut that corresponds to the instance space from propositionalized attribute taxonomy and data. Our experimental results on University of California-Irvine (UCI) repository data sets show that the proposed algorithm can generate a classifier that is sometimes comparably compact and accurate to those produced by standard Naive Bayes learners.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.12
• /
• pp.2357-2364
• /
• 2008

In this paper, we consider the problem of exploiting a taxonomy of propositionalized attributes in order to generate compact and robust classifiers. We introduce Propositionalized Attribute Taxonomy guided Naive Bayes Learner (PAT-NBL), an inductive learning algorithm that exploits a taxonomy of propositionalized attributes as prior knowledge to generate compact and accurate classifiers. PAT-NBL uses top-down and bottom-up search to find a locally optimal cut that corresponds to the instance space from propositionalized attribute taxonomy and data. Our experimental results on University of California-Irvine (UCI) repository data set, show that the proposed algorithm can generate a classifier that is sometimes comparably compact and accurate to those produced by standard Naive Bayes learners.

• Proceedings of the Korean Information Science Society Conference
• /
• 2000.04b
• /
• pp.256-258
• /
• 2000

최근 들어, 여러 기계학습 알고리즘이 문서 분류와 여과에 사용되고 있다. 특히 AdaBoost와 같은 부스팅 알고리즘은 실세계의 문서 데이터에 사용되었을 때 비교적 좋은 성능을 보이는 것으로 알려져 있다. 그러나 지금까지의 부스팅 알고리즘은 모두 단어의 존재 여부만을 가지고 판단하는 분류자를 기반으로 하고 있기 때문에 가중치 정보를 충분히 사용할 수 없다는 단점이 있다. 이 논문에서는 나이브 베이스를 사용한 부스팅 알고리즘은 단어의 가중치 정보를 효율적으로 사용할 수 있을 뿐 아니라. 확률적으로도 의미있는 신뢰도(confidence ratio)를 생성 할 수 있기 때문이다. TREC-7과 TREC-8의 정보 여과 트랙(filtering track)에 대해서 실험한 결과 좋은 성능을 보여주었다.

• Journal of KIISE:Databases
• /
• v.37 no.6
• /
• pp.285-291
• /
• 2010

In this paper, we propose a new paradigm of weighting methods for naive Bayesian learning. We propose more fine-grained weighting methods, called value weighting method, in the context of naive Bayesian learning. While the current weighting methods assign a weight to an attribute, we assign a weight to an attribute value. We develop new methods, using Kullback-Leibler function, for both value weighting and feature weighting in the context of naive Bayesian. The performance of the proposed methods has been compared with the attribute weighting method and general naive bayesian. The proposed method shows better performance in most of the cases.

• Journal of the Korean Society for information Management
• /
• v.22 no.2 s.56
• /
• pp.125-145
• /
• 2005

This paper presents a semantic vector space retrieval model incorporating a word sense disambiguation algorithm in an attempt to improve retrieval effectiveness. Nine Korean homonyms are selected for the sense disambiguation and retrieval experiments. The total of approximately 120,000 news articles comprise the raw test collection and 18 queries including homonyms as query words are used for the retrieval experiments. A Naive Bayes classifier and EM algorithm representing supervised and unsupervised learning algorithms respectively are used for the disambiguation process. The Naive Bayes classifier achieved $92\%$ disambiguation accuracy. while the clustering performance of the EM algorithm is $67\%$ on the average. The retrieval effectiveness of the semantic vector space model incorporating the Naive Bayes classifier showed $39.6\%$ precision achieving about $7.4\%$ improvement. However, the retrieval effectiveness of the EM algorithm-based semantic retrieval is $3\%$ lower than the baseline retrieval without disambiguation. It is worth noting that the performances of disambiguation and retrieval depend on the distribution patterns of homonyms to be disambiguated as well as the characteristics of queries.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04b
• /
• pp.304-306
• /
• 2001

많은 실세계의 문제에서 일반적인 패턴 분류 알고리즘들은 데이터의 불균형 문제에 어려움을 겪는다. 각각의 학습 예제에 균등한 중요도를 부여하는 기존의 기법들은 문제의 특징을 제대로 파악하지 못하는 경우가 많다. 본 논문에서는 불균형 데이터 문제를 해결하기 위해 퍼셉트론에 기반한 부스팅 기법을 제안한다. 부스팅 기법은 학습을 어렵게 하는 데이터에 집중하여 앙상블 머신을 구축하는 기법이다. 부스팅 기법에서는 약학습기를 필요로 하는데 기존 퍼셉트론의 경우 문제에 따라 약학습기(weak learner)의 조건을 만족시키지 못하는 경우가 있을 수 있다. 이에 커널을 도입한 커널 퍼셉트론을 사용하여 학습기의 표현 능력을 높였다. Reuters-21578 문서 집합을 대상으로 한 문서 여과 문제에서 부스팅 기법은 다층신경망이나 나이브 베이스 분류기보다 우수한 성능을 보였으며, 인공 데이터 실험을 통하여 부스팅의 샘플링 경향을 분석하였다.