• 정보관리학회지
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• 제15권3호
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• pp.45-71
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• 1998

인터넷 정보자원의 폭발적인 증가에 따라 이를 효율적으로 조직화하고 체계화하는 시스템의 중요성이 증가하고 있다. 이에 따라 주제접근을 용이하게 하고 검색 효율성을 높이는 도구로서 분류체계에 대한 관심이 커지고 있다. 본 고에서는 문헌 분류체계와 인터넷기반 분류체계의 계층구조와 접근방법을 구조적 측면과 검색사례를 통하여 조사하고 이에 대한 비교 분석을 통해 인터넷 환경에 적합한 분류체계의 구성방안을 살펴보았다.

• International Journal of Contents
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• 제13권2호
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• pp.66-74
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• 2017

Patent classification is becoming more critical as patent filings have been increasing over the years. Despite comprehensive studies in the area, there remain several issues in classifying patents on IPC hierarchical levels. Not only structural complexity but also shortage of patents in the lower level of the hierarchy causes the decline in classification performance. Therefore, we propose a new method of classification based on different criteria that are categories defined by the domain's experts mentioned in trend analysis reports, i.e. Patent Landscape Report (PLR). Several experiments were conducted with the purpose of identifying type of features and weighting methods that lead to the best classification performance using Support Vector Machine (SVM). Two types of features (noun and noun phrases) and five different weighting schemes (TF-idf, TF-rf, TF-icf, TF-icf-based, and TF-idcef-based) were experimented on.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.169-180
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• 2021

Since machine learning was invented, there have been many different machine learning-based algorithms, from shallow learning to deep learning models, that provide solutions to the classification tasks. But then it poses a problem in choosing a suitable classification algorithm that can improve the classification/detection efficiency for a certain network context. With that comes whether an algorithm provides good performance, why it works in some problems and not in others. In this paper, we present a data-centric analysis to provide a way for selecting a suitable classification algorithm. This data-centric approach is a new viewpoint in exploring relationships between classification performance and facts and figures of data sets.

• 한국안전학회지
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• 제20권2호
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• pp.127-132
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• 2005

The purpose of this study is to compare representative posture classification schemes of OWAS, RULA and REBA in terms of correctness for postural load. The comparison was based on the evaluation results by the three methods for 224 working postures sampled from steel, electronics, automotive, and chemical industries. The results showed that OWAS and REBA generally underestimated postural stress than RULA irrespective of industry type, work performed and whether or not leg posture is balanced. While about $71\%\;and\;73\%$ of the 224 posture were evaluated with the action category/level 1 or 2 by OWAS and REBA respectively, about $60\%$ of the postures were classified into the action level of 3 or 4 by RULA. The coincidence rate of postural stress category between OWAS and RULA was just $33.5\%$, while the rate between RULA and REBA was $46.0\%$. It is concluded from the findings of this study and the previous research that compared to OWAS and REBA, RULA more precisely evaluates postural stress.

• 한국산업정보학회논문지
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• 제12권4호
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• pp.41-54
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• 2007

주문 검토 및 투입(ORR; Order Review/Release) 모형의 활발한 활용을 위해서는 ORR모형의 분석과, 사용 환경에 맞는 분류가 이뤄져야 한다. 본 논문은 ORR의 역할과 관련 패러독스를 소개하고, ORR의 DSS화를 위한 분류체계를 제시한다. "COMPACT(COMplexity-imPACT) 매트릭스"라 명명된 ORR모형 분류체계는 복잡성에 따라 모형을 분류하고 각 복잡성 단계에서 모형의 유효성을 평가한 결과물이다. 이 분류체계는 사용자가 설정한 복잡성 정도에 맞춰 효과적인 모형을 제시한다는 사상을 통해 ORR모형의 DSS화와 활용에 기여할 것이다.

• Journal of Information Processing Systems
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• 제17권1호
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• pp.178-190
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• 2021

Alzheimer's disease (AD) is an insidious and degenerative neurological disease. It is a new topic for AD patients to use magnetic resonance imaging (MRI) and computer technology and is gradually explored at present. Preprocessing and correlation analysis on MRI data are firstly made in this paper. Then kernel principal component analysis (KPCA) is used to extract features of brain gray matter images. Finally supervised classification schemes such as AdaBoost algorithm and support vector machine algorithm are used to classify the above features. Experimental results by means of AD program Alzheimer's Disease Neuroimaging Initiative (ADNI) database which contains brain structural MRI (sMRI) of 116 AD patients, 116 patients with mild cognitive impairment, and 117 normal controls show that the proposed method can effectively assist the diagnosis and analysis of AD. Compared with principal component analysis (PCA) method, all classification results on KPCA are improved by 2%-6% among which the best result can reach 84%. It indicates that KPCA algorithm for feature extraction is more abundant and complete than PCA.

• 한국전자거래학회지
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• 제12권2호
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• pp.111-132
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• 2007

웹 기능의 향상과 웹 관련 기술의 발전, 레거시 시스템과의 통합 필요성 증대, 자주 변하는 웹 콘텐츠와 구조 등으로 인하여 웹 애플리케이션을 개발하고 관리하는 일이 과거보다 훨씬 더 복잡하게 되었다. 그러나 이러한 다양한 요인들을 고려하는 포괄적인 웹 애플리케이션 설계 방법론은 아직 존재하지 않고 있다. 따라서 본 연구에서는 이러한 요인들을 고려한 컨텍스트 기반의 웹 애플리케이션 설계 방법론을 제시하고자 한다. 본 연구에서 제시하는 방법론에서는 웹 정보를 전달하는 메커니즘에 따라 구분되는 9 종류의 웹 페이지 형태와 웹 페이지 간의 다양한 의미 관계를 정의하는 7 종류의 링크 형태 및 설계 과정 중에 사용되는 여러 종류의 컴포넌트 역할을 구별하는 소프트웨어 컴포넌트 형태 등 다양한 종류의 모델링 기법들을 소개하고 있다. 뿐만 아니라 이 방법론은 '콤펜디엄(compendium)' 이라 불리는 일단의 관련된 정보 클러스터들로 이루어진 독창적인 웹 애플리케이션 모델을 사용하고 있다. 하나의 콤펜디엄은 주제(theme), 컨텍스트 페이지, 링크 및 컴포넌트로 구성된다. 이러한 접근 방법은 모듈 방식의 설계에 유용할 뿐만 아니라 항상 변하는 웹 애플리케이션의 콘텐츠와 구조를 관리하는데도 도움이 된다. 본 연구에서 제시한 방법론은 의미적으로 응집력이 있고 구문적으로 느슨히 결합된 유연한 웹 디자인 산출물을 생성하는데 도움이 될 것이다.

• Journal of Electrical Engineering and Technology
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• 제1권2호
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• pp.257-262
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• 2006

Insulation failure in an electrical utility depends on the continuous stress imposed upon it. Monitoring of the insulation condition is a significant issue for safe operation of the electrical power system. In this paper, comparison of recognition rate variable classification scheme of PD (partial discharge) sources that occur within an electrical utility are studied. To acquire PD data, five defective models are made, that is, air discharge, void discharge and three types of treeinging discharge. Furthermore, these statistical distributions are applied to classify PD sources as the input data for the classification tools. ANFIS shows the highest rate, the value of which is 99% and PCA-LDA and ANFIS are superior to BP in regards to other matters.

• 한국멀티미디어학회논문지
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• 제21권3호
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• pp.391-399
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• 2018

In this paper, we construct and compare various guitar chord classification systems using perceptron neural network and convolutional neural network without pre-processing other than Fourier transform to identify the optimal chord classification system. Conventional guitar chord classification schemes use, for better feature extraction, computationally demanding pre-processing techniques such as stochastic analysis employing a hidden markov model or an acoustic data filtering and hence are burdensome for real-time chord classifications. For this reason, we construct various perceptron neural networks and convolutional neural networks that use only Fourier tranform for data pre-processing and compare them with dataset obtained by playing an electric guitar. According to our comparison, convolutional neural networks provide optimal performance considering both chord classification acurracy and fast processing time. In particular, convolutional neural networks exhibit robust performance even when only small fraction of low frequency components of the data are used.

• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2089-2098
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• 2017

Microgrid is a convenient, reliable, and eco-friendly approach for the integration of Distributed Generation (DG) sources into the utility power systems. To date, AC microgrids have been the most common architecture, but DC microgrids are gaining an increasing interest owing to the provision of numerous benefits in comparison with AC ones. These benefits encompass higher reliability, power quality and transmission capacity, non-complex control as well as direct connection to some DG sources, loads and Energy Storage Systems (ESSs). In this paper, main challenges and available approaches for the protection of AC and DC microgrids are discussed. After description, analysis and classification of the existing schemes, some research directions including coordination between AC and DC protective devices as well as development of combined control and protection schemes for the realization of future hybrid AC/DC microgrids are pointed out.