• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권1호
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• pp.15-28
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• 2018

Recently Machine Learning algorithms are widely used to process Big Data in various applications and a lot of these applications are executed in run time. Therefore the speed of Machine Learning algorithms is a critical issue in these applications. However the most of modern iteration Machine Learning algorithms use a successive iteration technique well-known in Numerical Linear Algebra. But this technique has a very low convergence, needs a lot of iterations to get solution of considering problems and therefore a lot of time for processing even on modern multi-core computers and clusters. Tchebychev iteration technique is well-known in Numerical Linear Algebra as an attractive candidate to decrease the number of iterations in Machine Learning iteration algorithms and also to decrease the running time of these algorithms those is very important especially in run time applications. In this paper we consider the usage of Tchebychev iterations for acceleration of well-known K-Means and SVM (Support Vector Machine) clustering algorithms in Machine Leaning. Some examples of usage of our approach on modern multi-core computers under Apache Spark framework will be considered and discussed.

• 한국정보전자통신기술학회논문지
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• 제13권4호
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• pp.283-292
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• 2020

4차 산업혁명의 대표적인 이미지 중 하나인 인공지능은 2016년 알파고 이후에 인공지능 인식이 매우 높아져 있다. 본 논문은 학국교육학술정보원에서 제공하는 국내 논문 중 '인공지능', '기계학습', '딥 러닝'으로 검색된 국내 발표 논문에 대해서 분석하였다. 검색된 논문은 약 1만여건이며 논문 동향을 파악하기 위해 빈도분석과 토픽 모델링, 의미 연결망을 이용하였다. 추출된 논문을 분석한 결과, 2015년에 비해 2016년에는 인공지능 분야는 600%, 기계학습은 176%, 딥 러닝 분야는 316% 증가하여 알파고 이후에 인공지능 분야의 연구가 활발히 진행됨을 확인할 수 있었다. 또한, 2018년 부터는 기계학습보다 딥 러닝 분야가 더 많이 연구 발표되고 있다. 기계학습에서는 서포트 벡터 머신 모델이, 딥 러닝에서는 텐서플로우를 이용한 컨볼루션 신경망이 많이 활용되고 있음을 알 수 있었다. 본 논문은 '인공지능', '기계학습', '딥 러닝' 분야의 향후 연구 방향을 설정하는 도움을 제공할 수 있다.

• 디지털산업정보학회논문지
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• 제19권3호
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• pp.149-163
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• 2023

In this study we analyze research trends on machine learning healthcare based on papers from the United States, the United Kingdom, and Korea. In Elsevier's Scopus, we collected 3425 papers related to machine learning healthcare published from 2018 to 2022. Keyword frequency and centrality analysis were conducted using the abstracts of the collected papers. We identified keywords with high frequency of appearance by calculating keyword frequency and found central research keywords through the centrality analysis by country. Through the analysis results, research related to machine learning, deep learning, healthcare, and the covid virus was conducted as the most central and highly mediating research in each country. As the implication, studies related to electronic health information-based treatment, natural language processing, and privacy in Korea have lower degree centrality and betweenness centrality than those of the United States and the United Kingdom. Thus, various convergence research applied with machine learning is needed for these fields.

• ETRI Journal
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• 제42권2호
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• pp.292-304
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• 2020

As side-channel analysis and machine learning algorithms share the same objective of classifying data, numerous studies have been proposed for adapting machine learning to side-channel analysis. However, a drawback of machine learning algorithms is that their performance depends on human engineering. Therefore, recent studies in the field focus on exploiting deep learning algorithms, which can extract features automatically from data. In this study, we survey recent advances in deep learning-based side-channel analysis. In particular, we outline how deep learning is applied to side-channel analysis, based on deep learning architectures and application methods. Furthermore, we describe its properties when using different architectures and application methods. Finally, we discuss our perspective on future research directions in this field.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제9권1호
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• pp.25-32
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• 2020

다양한 분야에서 활용되는 상황인지 시스템은 상황정보를 획득하기 위한 추상화 과정에서 규칙 기반의 인공기능 기술이 기존에 사용되었다. 그러나 서비스에 대한 사용자의 요구사항이 다양해지고 사용되는 데이터의 증대로 규칙이 복잡해지면서 규칙 기반 모델의 유지보수와 비정형 데이터를 처리하는데 어려움이 있다. 이러한 한계점을 극복하기 위해 많은 연구들에서는 상황인지 시스템에 기계학습 기술을 적용하였으며, 이러한 기계학습 기반의 모델을 상황인지 시스템에 사용하기 위해서는 주기적으로 학습 데이터를 제공해야 한다. 이에 기계학습 기반 상황인지 시스템에 대한 선행연구에서는 여러 개의 기계학습 모델을 적용하기 위한 학습 데이터 생성, 제공 등의 과정을 보였으나 제한된 종류의 기계학습 모델만을 적용 가능하여 확장성이 고려되어야 한다. 본 논문은 기계학습 기반의 상황인지 시스템의 확장성을 고려한 기계학습 모델의 학습 데이터 생성 방법을 제안한다. 제안하는 방법은 시스템의 확장성을 고려하여 기계학습 모델의 요구사항을 반영할 수 있는 학습 데이터 생성 모델을 정의하고 학습 데이터 생성 모듈을 바탕으로 각각의 기계학습 모델의 학습 데이터를 생성하는 것이다. 시스템의 확장성의 검증을 위해 실험에서는 노인의 건강상태 알림 서비스를 위한 심박상태 분석 모델을 대상으로 한 학습데이터 생성 스키마를 기반으로 학습데이터 생성 모델을 정의하고 실환경에서 정의된 모델을 S/W에 적용하여 학습데이터를 생성한다. 또한 생성된 학습데이터의 유효성을 검증하기 위해 사용되는 기계학습 모델에 생성한 학습데이터를 학습시켜 정확도를 비교하는 과정을 보인다.

• 스마트미디어저널
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• 제10권1호
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• pp.25-31
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• 2021

기계학습이 보편화되면서 기계학습을 활용한 응용 개발 또한 활발하게 이루어지고 있다. 또한 이러한 응용 개발을 지원하기 위한 기계학습 플랫폼 연구도 활발하게 진행되고 있다. 그러나 기계학습 플랫폼 연구가 활발하게 진행되고 있음에도 불구하고 기계학습 플랫폼에 적절한 부하 분산에 관한 연구는 아직 부족하다. 따라서 본 논문에서는 기계학습 분산 환경을 위한 부하 분산 기법을 제안한다. 제안하는 기법은 분산 서버를 레벨 해시 테이블 구조로 구성하고 각 서버의 성능을 고려하여 기계학습 작업을 서버에 할당한다. 이후 분산 서버를 구현하여 실험하고 기존 해싱 기법과 성능을 비교하였다. 제안하는 기법을 기존 해싱 기법과 비교하였을 때 평균 약 26%의 속도 향상을 보였고, 서버에 할당되지 못하고 대기하는 작업의 수가 약 38% 이상 감소함을 보였다.

• 농업과학연구
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• 제49권3호
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• pp.619-627
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• 2022

In Korea, apples and pears are among the most important agricultural products to farmers who seek to earn money as income. Generally, farmers make decisions at various stages to maximize their income but they do not always know exactly which option will be the best one. Many previous studies were conducted to solve this problem by predicting farmers' income structure, but researchers are still exploring better approaches. Currently, machine learning technology is gaining attention as one of the new approaches for farmers' income prediction. The machine learning technique is a methodology using an algorithm that can learn independently through data. As the level of computer science develops, the performance of machine learning techniques is also improving. The purpose of this study is to predict the income structure of apples and pears using the automatic machine learning solution H2O.AI and to present some implications for apple and pear farmers. The automatic machine learning solution H2O.AI can save time and effort compared to the conventional machine learning techniques such as scikit-learn, because it works automatically to find the best solution. As a result of this research, the following findings are obtained. First, apple farmers should increase their gross income to maximize their income, instead of reducing the cost of growing apples. In particular, apple farmers mainly have to increase production in order to obtain more gross income. As a second-best option, apple farmers should decrease labor and other costs. Second, pear farmers also should increase their gross income to maximize their income but they have to increase the price of pears rather than increasing the production of pears. As a second-best option, pear farmers can decrease labor and other costs.

• 한국경영과학회지
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• 제19권2호
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• pp.153-176
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• 1994

In this paper we introduce machine learning theory to business domains for business decisions. First, we review machine learning in general. We give a new look on a previous framework, version space approach, and we introduce PAC (probably approximately correct) learning paradigm which has been developed recently. We illustrate major results of PAC learning with business examples. And then, we give a theoretical analysis is decision tree induction algorithms by the frame work of PAC learning. Finally, we will discuss implications of learning theory toi business domains.

• 한국측량학회지
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• 제34권4호
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• pp.383-390
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• 2016

Remote sensing data has been widely used in the estimation of crop yields by employing statistical methods such as regression model. Machine learning, which is an efficient empirical method for classification and prediction, is another approach to crop yield estimation. This paper described the corn yield estimation in Iowa State using four machine learning approaches such as SVM (Support Vector Machine), RF (Random Forest), ERT (Extremely Randomized Trees) and DL (Deep Learning). Also, comparisons of the validation statistics among them were presented. To examine the seasonal sensitivities of the corn yields, three period groups were set up: (1) MJJAS (May to September), (2) JA (July and August) and (3) OC (optimal combination of month). In overall, the DL method showed the highest accuracies in terms of the correlation coefficient for the three period groups. The accuracies were relatively favorable in the OC group, which indicates the optimal combination of month can be significant in statistical modeling of crop yields. The differences between our predictions and USDA (United States Department of Agriculture) statistics were about 6-8 %, which shows the machine learning approaches can be a viable option for crop yield modeling. In particular, the DL showed more stable results by overcoming the overfitting problem of generic machine learning methods.

• 대한방사선기술학회지:방사선기술과학
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• 제42권1호
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• pp.9-17
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• 2019

Although digital mammography is a representative method for breast cancer detection. It has a limitation in detecting and classifying breast tumor due to superimposed structures. Machine learning, which is a part of artificial intelligence fields, is a method for analysing a large amount of data using complex algorithms, recognizing patterns and making prediction. In this study, we proposed a technique to improve the diagnostic accuracy of energy-selective mammography by training data using the machine learning algorithm and using dual-energy measurements. A dual-energy images obtained from a photon-counting detector were used for the input data of machine learning algorithms, and we analyzed the accuracy of predicted tumor thickness for verifying the machine learning algorithms. The results showed that the classification accuracy of tumor thickness was above 95% and was improved with an increase of imput data. Therefore, we expect that the diagnostic accuracy of energy-selective mammography can be improved by using machine learning.