• Communications for Statistical Applications and Methods
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• 제28권1호
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• pp.89-97
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• 2021

Due to boundedness and sum constraint, compositional data are often transformed by logratio transformation and their transformed data are put into traditional binary classification or discriminant analysis. However, it may be problematic to directly apply traditional multivariate approaches to the transformed data because class distributions are not Gaussian and Bayes decision boundary are not polynomial on the transformed space. In this study, we propose to use flexible classification approaches to transformed data for compositional data classification. Empirical studies using synthetic and real examples demonstrate that flexible approaches outperform traditional multivariate classification or discriminant analysis.

• 수산해양교육연구
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• 제29권3호
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• pp.689-701
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• 2017

In recent offshore industries, various ambiguous terms have been used without clear definition or classification, causing difficulties in legal, technical, and educational understanding and usage. For an example, the commonly used term of 'Offshore Plant' in Korea is not an universal word technically. There has been no clear technical or legal definition about the 'Offshore Plant' and its classification is also very ambiguous; sometimes it is used to refer offshore oil and gas production platform or it is used to mean offshore renewable power generation plant in some cases. To build a conceptual framework, therefore, this paper suggests a classification of offshore units (1) using internationally agreed terms, (2) agreed with the technical classification used by the ship classification society and (3) being able to include not only the current but also future concepts of offshore units.

• 한국멀티미디어학회논문지
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• 제23권3호
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• pp.447-459
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• 2020

The Internet of Things(IoT) paradigm is flourishing strenuously for the last two decades. Researchers around the globe have their dreams to transmute every real-world object to the virtual object. Consequently, IoT devices are escalating exponentially. The abrupt evolution of these IoT devices has caused a major challenge i.e. object classification. In order to classify devices comprehensively and accurately, this paper proposes a context-aware based multi-classification model for devices, which classifies the smart devices according to people's contexts. However, the classification features of contextual data of different contexts are difficult to extract. The deep learning algorithm has the capability to solve this problem. This paper proposes a context-aware based multi-classification model of devices, which classifies the smart devices according to people's contexts.

• 한국도서관정보학회지
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• 제37권1호
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• pp.329-352
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• 2006

이 연구는 우리나라 근대문헌분류사의 중요한 분류표의 하나인 한은도서분류법의 편찬 및 개정 경위를 살펴보고 편찬당시 참조한 각종 분류표와 이를 비교하고 분류표 자체를 구체적으로 분석하였다. 한은도서분류법은 한국은행정보자료실에서 사용할 목적으로 초판을 간행하였고, 이후 한차례 수정판을 간행하였다. 그리고 편찬 당시 주요 주류와 조기표에서 NDC를 참조한 것으로 나타났으며, 종교와 어학, 문학에서는 KDCP를 참조한 것으로 나타났다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 춘계학술발표대회
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• pp.787-790
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• 2017

Data quality is the main issue in the classification problems; generally, the presence of noisy instances in the training dataset will not lead to robust classification performance. Such instances may cause the generated decision tree to suffer from over-fitting and its accuracy may decrease. Decision trees are useful, efficient, and commonly used for solving various real world classification problems in data mining. In this paper, we introduce a preprocessing technique to improve the classification accuracy rates of the C4.5 decision tree algorithm. In the proposed preprocessing method, we applied the naive Bayes classifier to remove the noisy instances from the training dataset. We applied our proposed method to a real e-commerce sales dataset to test the performance of the proposed algorithm against the existing C4.5 decision tree classifier. As the experimental results, the proposed method improved the classification accuracy by 8.5% and 14.32% using training dataset and 10-fold crossvalidation, respectively.

• 로봇학회논문지
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• 제5권4호
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• pp.339-348
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• 2010

One of the requirements for autonomous vehicles on off-road is to move stably in unstructured environments. Such capacity of autonomous vehicles is one of the most important abilities in consideration of mobility. So, many researchers use contact and/or non-contact methods to determine a terrain whether the vehicle can move on or not. In this paper we introduce an algorithm to classify terrains using visual information(one of the non-contacting methods). As a pre-processing, a contrast enhancement technique is introduced to improve classification of terrain. Also, for conducting classification algorithm, training images are grouped according to materials of the surface, and then Bayesian classification are applied to new images to determine membership to each group. In addition to the classification, we can build Traversability map specified by friction coefficients on which autonomous vehicles can decide to go or not. Experiments are made with Load-Cell to determine real friction coefficients of various terrains.

• 한국멀티미디어학회논문지
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• 제20권10호
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• pp.1637-1645
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• 2017

Target/Nontarget classification can be divided into the study of shape estimation of the target analysing reflected echo signal and of type classification of the target using acoustical features. In active sonar system, the feature vectors are extracted from the signal reflected from the target, and an classification algorithm is applied to determine whether the received signal is a target or not. However, received sonar signals can be distorted in the underwater environments, and the spatio-temporal characteristics of active sonar signals change according to the aspect of the target. In addition, it is very difficult to collect real sea-trial data for research. In this paper, target/non-target classification were performed using real sea-trial data. Feature vectors are extracted using MFCC(Mel-Frequency Cepstral Coefficients), filterbank energy in the Fourier spectrum and wavelet domain. For the performance verification, classification experiments were performed using backpropagation neural network classifiers.

• 정보관리학회지
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• 제18권4호
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• pp.201-215
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• 2001

인터넷 쇼핑몰의 상품에 대한 분류체계를 도서관 분류이론에 적용하여, 효과적인 분류체계 구축을 위한 기준점을 파악하고자 하였다. 연구 방법은 기존의 웹 쇼핑몰 세 곳을 선정하여, 분류체계를 Ranganathan의 분류이론을 기준으로 하여 비교 분석하였다. 결과 크게 6가지 기준들이 파악되었는데, 상품의 특성, 범주의 포괄성, 다양한 접근점, 범부의 배열순서와 용어의 일관성, 용어의 최신성과 명백성, 용어의 반복적 사용의 금지들이었다. 추후 연구과제로 상품 탐색 형태와 인터페이스와의 관련성이 제시되었다.

• 한국문헌정보학회지
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• 제48권4호
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• pp.5-23
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• 2014

This study reports the first step in the Classification-based Search and Knowledge Discovery (CSKD) project, which aims to combine information organization and retrieval approaches for building digital library applications. In this study, we explored the generation and application of a faceted vocabulary as a potential mechanism to enhance knowledge discovery. The faceted vocabulary construction process revealed some heuristics that can be refined in follow-up studies to further automate the creation of faceted classification structure, while our concept search application demonstrated the utility and potential of integrating classification-based approach with retrieval-based approach. Integration of text- and classification-based methods as outlined in this paper combines the strengths of two vastly different approaches to information discovery by constructing and utilizing a flexible information organization scheme from an existing classification structure.

• 한국측량학회지
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• 제5권2호
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• pp.24-33
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• 1987

본 논문은 원격탐사 Data를 이용한 분야에서 보다 효과적인 좌상처리 기법 및 보다 정확한 분류화상을 얻는 것을 목적으로 하고 있다. 이의 실행을 위해 여름 좌상과 겨울 화상을 합성한 토지이용 분류결과와 여름 화상만의 분류결과를 비교분석 하였다. 위의 분석결과로부터 Bitemporal Classification 기법과 $tan^{-1}$변환이 유효함을 알아내었다. 특히 Bitemporal Classification 기법을 적용함으로써 농경지를 논과 밭으로 구별하여 분류하는 것이 보다 가능하였다.