• Journal of the Korean Data and Information Science Society
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• 제14권3호
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• pp.641-651
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• 2003

This study suggests the hybrid models for interest rate forecasting using structural changes (or change points). The basic concept of this proposed model is to obtain significant intervals caused by change points, to identify them as the change-point groups, and to reflect them in interest rate forecasting. The model is composed of three phases. The first phase is to detect successive structural changes in the U. S. Treasury bill rate dataset. The second phase is to forecast the change-point groups with data mining classifiers. The final phase is to forecast interest rates with backpropagation neural networks (BPN). Based on this structure, we propose three hybrid models in terms of data mining classifier: (1) multivariate discriminant analysis (MDA)-supported model, (2) case-based reasoning (CBR)-supported model, and (3) BPN-supported model. Subsequently, we compare these models with a neural network model alone and, in addition, determine which of three classifiers (MDA, CBR and BPN) can perform better. For interest rate forecasting, this study then examines the prediction ability of hybrid models to reflect the structural change.

• 산업경영시스템학회지
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• 제43권3호
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• pp.112-121
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• 2020

Recently, as the internet usage is increasing, accordingly generated text data is also increasing. Because this text data on the internet includes users' comments, the text data on the Internet can help you get users' opinion more efficiently and effectively. The topic of text mining has been actively studied recently, but it primarily focuses on either the content analysis or various improving techniques mostly for the performance of target mining algorithms. The objective of this study is to propose a novel method of analyzing the user's requirements by utilizing the text-mining technique. To complement the existing survey techniques, this study seeks to present priorities together with efficient extraction of customer requirements from the text data. This study seeks to identify users' requirements, derive the priorities of requirements, and identify the detailed causes of high-priority requirements. The implications of this study are as follows. First, this study tried to overcome the limitations of traditional investigations such as surveys and VOCs through text mining of online text data. Second, decision makers can derive users' requirements and prioritize without having to analyze numerous text data manually. Third, user priorities can be derived on a quantitative basis.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 추계학술대회
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• pp.59-69
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• 2005

Data mining technique is used to find hidden knowledge by massive data, unexpectedly pattern, relation to new rule. The methods of data mining are decision tree, association rules, clustering, neural network and so on. Clustering is the process of grouping the data into clusters so that objects within a cluster have high similarity in comparison to one another. It has been widely used in many applications, such that pattern analysis or recognition, data analysis, image processing, market research on off-line or on-line and so on. We analyze Gyeongnam social indicator survey data by 2001 using twostep clustering technique for environment information. The twostep clustering is classified as a partitional clustering method. We can apply these twostep clustering outputs to environmental preservation and improvement.

• 지능정보연구
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• 제10권2호
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• pp.15-37
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• 2004

최근 데이터 양이 급증하면서 데이터 마이닝에 대한 연구가 활발하게 진행되고 있으며 특히 GPS 시스템, 감시시스템, 기상 관측 시스템과 같은 다양한 응용 시스템으로부터 수집된 데이터를 분석하고자 하는 시공간 데이터 마이닝 연구에 대한 관심이 더욱 높아지고 있다. 기존의 시공간 데이터 마이닝 연구들에서는 비시공간 데이터 기반의 일반적인 클러스터링 기법들을 그대로 적용하고 있으나 데이터의 속성이 다른 시공간 데이터 마이닝에서 기존의 알고리즘들이 어느 정도의 성능을 보장하는지, 데이터의 시공간 속성에 따라 적절한 마이닝 알고리즘을 선택하기 위한 기준이 무엇인지 등에 대한 연구는 미흡한 실정이다. 본 논문에서는 기존의 시공간 데이터 마이닝 연구에서 일반적으로 많이 사용되어 온 알고리즘인 SOM(Self-Organizing Map)을 기반으로 시공간 데이터 마이닝 모듈을 개발하고, 개발된 클러스터링 모듈의 성능을 K-means과 두 가지 응집 계층(Hierarchical Agglomerative) 알고리즘들과 균질도, 분리도, 반면영상 너비, 정확도의 네 가지 평가 기준을 기반으로 비교하였다. 또한 입력 데이터의 특성 가시화 및 클러스터링 결과의 정확한 분석을 위해 시공간 데이터 클러스터링을 위한 가시화 모듈을 개발하였다.

• 한국정보전자통신기술학회논문지
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• 제8권6호
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• pp.544-550
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• 2015

현재, SNS으로 소통되는 의견들이 증가하고 있기 때문에 SNS 메시지로부터 의미 있는 정보를 유추해내는 오피니언 마이닝(Opinion mining) 기술이 중요해지고 있다. 본 논문은 반의어와 부사의 위치에 따라 가중치를 다르게 설정하여 SNS의 감성 정보를 정확하게 추출하는 오피니언 마이닝 기반 SNS 감성 정보 분석 전략(SEIAS, SNS Emotional Information Analysis Strategy)을 제안한다. 제안하는 SEIAS(SNS Emotional Information Analysis Strategy)는 첫째, 오피니언 마이닝 분석에 필요한 감성사전을 구축하고, 둘째, SNS 데이터를 실시간으로 수집하고, 수집된 SNS 데이터와 감성사전를 비교하여 SNS 데이터의 의견값을 산출한다. 특히, 데이터의 의견값을 산출할 때, 반의어, 부사의 위치에 따라 가중값을 다르게 설정함으로써 기존의 SO-PMI와 비교하였을 때 오피니언 분석결과의 정확도를 향상시켰다.

• 한국정보시스템학회지:정보시스템연구
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• 제22권3호
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• pp.25-42
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• 2013

Recently various kinds of Information Technology services are created and the quantities of the data flow are increase rapidly. Not only that, but the data patterns that we deal with also slowly becoming diversity. As a result, the demand of discover the meaningful knowledge/information through the various mining analysis such as linkage analysis, sequencing analysis, classification and prediction, has been steadily increasing. However, solving the business problems using data mining analysis does not always concerning, one of the major causes of these limitations is there are some analyzed data can't accurately reflect the real world phenomenon. For example, although the time gap of purchasing the two products is very short, by using the traditional sequencing analysis, the precedence relationship of the two products is clearly reflected. But in the real world, with the very short time interval, the precedence relationship of the two purchases might not be defined. What was worse, the sequence of the purchase intention and the sequence of the purchase realization of the two products might be mutually be reversed. Therefore, in this study, an expanded sequencing analysis methodology has been proposed in order to reflect this situation. In this proposed methodology, the purchases that being made in a very short time interval among the purchase order which might not important will be notice, and the analysis which included the original sequence and reversed sequence will be used to extend the analysis of the data. Also, to some extent a very short time interval can be defined as the time interval, so an experiment were carried out to determine the varying based on the time interval for the actual data.

• Journal of the Korean Data and Information Science Society
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• 제20권2호
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• pp.425-433
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• 2009

데이터마이닝은 방대한 양의 데이터 속에서 유용한 정보를 찾아내는 과정이며, 이를 위해 데이터마이닝 도구가 필요하다. 데이터마이닝 도구 또는 솔루션은 E-Miner, Clementine, WEKA, R 등 상당히 많은 종류가 있으나 대부분의 데이터마이닝 도구는 다양성과 범용성에 초점을 맞추어 개발되어 사용 편의성과 분석 자동화에 대해서는 소홀한 실정이어서 비전문가가 사용하기 어려운 경우가 대부분이다. 본 논문에서는 피에이치피와 웨카를 이용하여 인터넷 환경에서 데이터마이닝 기법을 실행하고, 생성된 분석결과를 보다 쉽게 해석할 수 있도록 개선하여 일반 사용자도 쉽게 사용할 수 있는 시스템을 설계하고 구현하고자 한다. 본 논문에서 구현하는 데이터마이닝 기법은 가장 많이이용되고 있는 연관성 규칙의 Apriori 알고리즘, 군집분석의 K-평균 알고리즘, 의사결정나무의 J48 알고리즘 등이다.

• Journal of the Korean Data and Information Science Society
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• 제14권4호
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• pp.725-736
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• 2003

To provide the information needed to make a decision, it is important to know the relationship or pattern between variables in database. Grouping objects which have similar characteristics of pattern is called as cluster analysis, one of data mining techniques. In this study, it is compared with several partitioning clustering algorithms, based on the statistical distance or total variance in each cluster.

• International Journal of Contents
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• 제3권2호
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• pp.18-24
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• 2007

Biological sequences such as DNA and amino acid sequences typically contain a large number of items. They have contiguous sequences that ordinarily consist of more than hundreds of frequent items. In biological sequences analysis(BSA), a frequent contiguous sequence search is one of the most important operations. Many studies have been done for mining sequential patterns efficiently. Most of the existing methods for mining sequential patterns are based on the Apriori algorithm. In particular, the prefixSpan algorithm is one of the most efficient sequential pattern mining schemes based on the Apriori algorithm. However, since the algorithm expands the sequential patterns from frequent patterns with length-1, it is not suitable for biological datasets with long frequent contiguous sequences. In recent years, the MacosVSpan algorithm was proposed based on the idea of the prefixSpan algorithm to significantly reduce its recursive process. However, the algorithm is still inefficient for mining frequent contiguous sequences from long biological data sequences. In this paper, we propose an efficient method to mine maximal frequent contiguous sequences in large biological data sequences by constructing the spanning tree with a fixed length. To verify the superiority of the proposed method, we perform experiments in various environments. The experiments show that the proposed method is much more efficient than MacosVSpan in terms of retrieval performance.

• Journal of the Korean Data and Information Science Society
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• 제16권4호
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• pp.801-813
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• 2005

The discretization algorithms for continuous data have been actively studied in the area of data mining. These discretizations are very important in data analysis, especially for efficient model selection in data mining. So, in this paper, we introduce the principles of some mutiway discretization algorithms including KEX, 1R and CN4 algorithm and investigate the efficiency of these algorithms through numerical study. For various underlying distribution, we compare these algorithms in view of misclassification rate.