• 한국전자통신학회논문지
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• 제14권3호
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• pp.547-552
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• 2019

최근, 빅데이터 분야에서는 빅 데이터의 양적 팽창이 주요 이슈로 떠오르고 있다. 더군다나 이러한 빅데이터는 기계학습의 입력값으로 사용되어지고 있으며 이들의 성능을 향상시키기 위해 정규화 전처리가 필요하다. 이러한 성능은 빅데이터 컬럼의 범위나 정규화 전처리 방식에 따라 크게 좌우된다. 본 논문에서는 다양한 종류의 정규화 전처리 방식과 빅데이터 컬럼의 범위를 조절하면서 서포트벡터머신(SVM)의 기계학습방식에 적용함으로써 더욱 효과적인 정규화 전처리 방식을 파악하고자 하였다. 이를 위하여 파이썬언어와 주피터 노트북 환경에서 기계학습을 수행하고 분석하였다.

• Wind and Structures
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• 제36권6호
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• pp.355-366
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• 2023

Although machine learning (ML) techniques have been widely used in various fields of engineering practice, their applications in the field of wind engineering are still at the initial stage. In order to evaluate the feasibility of machine learning algorithms for prediction of wind loads on high-rise buildings, this study took the exposure category type, wind direction and the height of local wind force as the input features and adopted four different machine learning algorithms including k-nearest neighbor (KNN), support vector machine (SVM), gradient boosting regression tree (GBRT) and extreme gradient (XG) boosting to predict wind force coefficients of CAARC standard tall building model. All the hyper-parameters of four ML algorithms are optimized by tree-structured Parzen estimator (TPE). The result shows that mean drag force coefficients and RMS lift force coefficients can be well predicted by the GBRT algorithm model while the RMS drag force coefficients can be forecasted preferably by the XG boosting algorithm model. The proposed machine learning based algorithms for wind loads prediction can be an alternative of traditional wind tunnel tests and computational fluid dynamic simulations.

• 디지털융복합연구
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• 제13권8호
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• pp.289-294
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• 2015

본 연구는 비교사학습의 대표적인 방법 중 하나인 코호넨의 자기조직화 방법을 기반으로 BCI(Brain-Computer Interface)에 적용 가능한 자율적 기계학습방법을 제안한다. 이를 위해 상호작용 함수를 이용한 학습영역조정방법과 자율적 기계학습규칙을 제안하였다. 학습영역조정과 기계학습은 코호넨의 자기조직화 방법을 기반으로 한 상호작용 함수에 의한 측면제어효과를 이용하였다. 승자 뉴런을 결정하고 난 후 학습 규칙에 따라 뉴런의 연결강도를 조정하고 학습 횟수가 증가함에 따라 학습영역이 점차 감소하여 출력층 뉴런 가중치들의 입력을 향한 유동을 완화시켜 네트워크가 평형 상태(equilibrium state)에 도달하여 학습을 마칠 수 있는 자율적 기계학습을 제안하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.3099-3120
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• 2023

The present fast-moving era brings a serious stress issue that affects elders and youngsters. Everyone has undergone stress factors at least once in their lifetime. Stress is more among youngsters as they are new to the working environment. whereas the stress factors for elders affect the individual and overall performance in an organization. Electroencephalogram (EEG) based stress level classification is one of the widely used methodologies for stress detection. However, the signal processing methods evolved so far have limitations as most of the stress classification models compute the stress level in a predefined environment to detect individual stress factors. Specifically, machine learning based stress classification models requires additional algorithm for feature extraction which increases the computation cost. Also due to the limited feature learning characteristics of machine learning algorithms, the classification performance reduces and inaccurate sometimes. It is evident from numerous research works that deep learning models outperforms machine learning techniques. Thus, to classify all the emotions based on stress level in this research work a hybrid deep learning algorithm is presented. Compared to conventional deep learning models, hybrid models outperforms in feature handing. Better feature extraction and selection can be made through deep learning models. Adding machine learning classifiers in deep learning architecture will enhance the classification performances. Thus, a hybrid convolutional neural network model was presented which extracts the features using CNN and classifies them through machine learning support vector machine. Simulation analysis of benchmark datasets demonstrates the proposed model performances. Finally, existing methods are comparatively analyzed to demonstrate the better performance of the proposed model as a result of the proposed hybrid combination.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권12호
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• pp.4308-4325
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• 2021

The importance and necessity of artificial intelligence, particularly machine learning, has recently been emphasized. In fact, artificial intelligence, such as intelligent surveillance cameras and other security systems, is used to solve various problems or provide convenience, providing solutions to problems that humans traditionally had to manually deal with one at a time. Among them, information security is one of the domains where the use of artificial intelligence is especially needed because the frequency of occurrence and processing capacity of dangerous codes exceeds the capabilities of humans. Therefore, this study intends to examine the definition of artificial intelligence and machine learning, its execution method, process, learning algorithm, and cases of utilization in various domains, particularly the cases and contents of artificial intelligence technology used in the field of information security. Based on this, this study proposes a method to apply machine learning technology to the method of classifying and detecting malware that has rapidly increased in recent years. The proposed methodology converts software programs containing malicious codes into images and creates training data suitable for machine learning by preparing data and augmenting the dataset. The model trained using the images created in this manner is expected to be effective in classifying and detecting malware.

• ETRI Journal
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• 제44권4호
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• pp.613-623
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• 2022

Autism spectrum disorder (ASD) is a developmental disorder associated with cognitive and neurobehavioral disorders. It affects the person's behavior and performance. Autism affects verbal and non-verbal communication in social interactions. Early screening and diagnosis of ASD are essential and helpful for early educational planning and treatment, the provision of family support, and for providing appropriate medical support for the child on time. Thus, developing automated methods for diagnosing ASD is becoming an essential need. Herein, we investigate using various machine learning methods to build predictive models for diagnosing ASD in children using facial images. To achieve this, we used an autistic children dataset containing 2936 facial images of children with autism and typical children. In application, we used classical machine learning methods, such as support vector machine and random forest. In addition to using deep-learning methods, we used a state-of-the-art method, that is, automated machine learning (AutoML). We compared the results obtained from the existing techniques. Consequently, we obtained that AutoML achieved the highest performance of approximately 96% accuracy via the Hyperpot and tree-based pipeline optimization tool optimization. Furthermore, AutoML methods enabled us to easily find the best parameter settings without any human efforts for feature engineering.

• 문화기술의 융합
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• 제7권2호
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• pp.427-436
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• 2021

본 연구의 목적은 문학 텍스트를 학습한 머신 러닝 언어 모델을 구현하는데 있다. 문학 텍스트는 일상 대화문처럼 질문에 대한 답변이 분명하게 구분되지 않을 때가 많고 대명사와 비유적 표현, 지문, 독백 등으로 다양하게 구성되어 있다는 특징이 있다. 이런 점들이 알고리즘의 학습을 용이하지 않게 하여 문학 텍스트를 활용하는 기계 학습의 필요성을 저해시킨다. 문학 텍스트를 학습한 알고리즘이 일반 문장을 학습한 알고리즘에 비해 좀 더 인간 친화적인 상호작용을 보일 가능성이 높다. 본 논문은 '문학 텍스트를 학습한 머신 러닝 언어 모델 구현'에 관한 연구로서, 대화형 기계 학습에 문학 텍스트를 활용하는 연구에서 필수적으로 선행되어야 할 세 가지 텍스트 보정 작업을 제안한다: 대명사 처리, 대화쌍 늘리기, 데이터 증폭 등에 대한 내용으로 기계 학습이 용이하고 그 효과도 높다고 판단됩니다. 인공지능을 위한 학습용 데이터는 그 의미가 명료해야 기계 학습이 용이하고 그 효과도 높게 나타난다. 문학과 같은 특수한 장르의 텍스트를 자연어 처리 연구에 도입하는 것은 새로운 언어 학습 방식의 제안과 함께 머신 러닝의 학습 영역도 확장시켜 줄 것이다.

• International Journal of Internet, Broadcasting and Communication
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• 제16권2호
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• pp.267-277
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• 2024

This paper explores the use of machine learning in game production to create goal-oriented, realistic animations for skeleton monsters. The purpose of this research is to enhance realism by implementing intelligent movements in monsters within game development. To achieve this, we designed and implemented a learning model for skeleton monsters using reinforcement learning algorithms. During the machine learning process, various reward conditions were established, including the monster's speed, direction, leg movements, and goal contact. The use of configurable joints introduced physical constraints. The experimental method validated performance through seven statistical graphs generated using machine learning methods. The results demonstrated that the developed model allows skeleton monsters to move to their target points efficiently and with natural animation. This paper has implemented a method for creating game monster animations using machine learning, which can be applied in various gaming environments in the future. The year 2024 is expected to bring expanded innovation in the gaming industry. Currently, advancements in technology such as virtual reality, AI, and cloud computing are redefining the sector, providing new experiences and various opportunities. Innovative content optimized for this period is needed to offer new gaming experiences. A high level of interaction and realism, along with the immersion and fun it induces, must be established as the foundation for the environment in which these can be implemented. Recent advancements in AI technology are significantly impacting the gaming industry. By applying many elements necessary for game development, AI can efficiently optimize the game production environment. Through this research, We demonstrate that the application of machine learning to Unity and game engines in game development can contribute to creating more dynamic and realistic game environments. To ensure that VR gaming does not end as a mere craze, we propose new methods in this study to enhance realism and immersion, thereby increasing enjoyment for continuous user engagement.

• 서비스연구
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• 제13권3호
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• pp.105-126
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• 2023

국내 중고차 시장은 지속적으로 성장하고 있으며, 이와 동시에 중고차 온라인 플랫폼 서비스 역시 함께 매년 시장 점유율을 확대하고 있다. 중고차 온라인 플랫폼 서비스는 차량의 제원, 점검 이력, 사고 내역, 그리고 세부 옵션 등을 서비스 이용자에게 제공하고 있다. 대부분의 기존 연구는 차량의 제원과 차량의 일부 옵션을 활용한 중고차 가격의 예측이었으며, 중고차 가격과 일부 제원 변수 간 비선형 관계임을 확인하였다. 이에 따라 연구자들은 이러한 비선형 문제를 해결하기 위해 머신러닝(Machine Learning) 모델의 실행을 제안하였으며, 그 결과 회귀(Regression) 기반 머신러닝 모델은 변수의 실질적인 영향력과 방향성을 알 수 있는 장점이 존재하였으나, 트리(Decision Tree) 기반 머신러닝 모델에 비해 비용함수 수치가 저조한 단점이 존재하였다. 본 연구는 국내 브랜드를 대상으로 차량의 제원과 차량의 옵션, 총 70여 개의 변수를 모두 활용하여 회귀 기반 머신러닝 모델과 트리 기반 머신러닝 모델을 순차적으로 실행하여 두 유형의 머신러닝 모델의 장점을 취합하고자 하였다. 이를 통해 브랜드별 변수의 실질적 영향력과 방향성을 확인한 후 브랜드별 가장 우수한 트리 기반 머신러닝 모델을 선정하였다. 본 연구의 시사점은 다음과 같다. 중고차 온라인 플랫폼 서비스를 이용하는 구매자와 판매자가 전반적인 중고차 가격 예측을 지원할 수 있다. 이에 따라 중고차 온라인 플랫폼 서비스 이용자 간 정보의 비대칭으로 인한 문제 해결 역시 지원이 가능할 것으로 기대한다.

• 의학교육논단
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• 제19권3호
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• pp.158-168
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• 2017

There is a more urgent call for educational methods of machine learning in medical education, and therefore, new approaches of teaching and researching machine learning in medicine are needed. This paper presents a case using machine learning through text analysis. Topic modeling of news articles with the keyword 'asbestos' were examined. Two hypotheses were tested using this method, and the process of machine learning of texts is illustrated through this example. Using an automated text analysis method, all the news articles published from January 1, 1990 to November 15, 2016 in South Korea which included 'asbestos' in the title and the body were collected by web scraping. Differences in topics were analyzed by structured topic modelling (STM) and compared by press companies and periods. More articles were found in liberal media outlets. Differences were found in the number and types of topics in the articles according to the partisanship and period. STM showed that the conservative press views asbestos as a personal problem, while the progressive press views asbestos as a social problem. A divergence in the perspective for emphasizing the issues of asbestos between the conservative press and progressive press was also found. Social perspective influences the main topics of news stories. Thus, the patients' uneasiness and pain are not presented by both sources of media. In addition, topics differ between news media sources based on partisanship, and therefore cause divergence in readers' framing. The method of text analysis and its strengths and weaknesses are explained, and an application for the teaching and researching of machine learning in medical education using the methodology of text analysis is considered. An educational method of machine learning in medical education is urgent for future generations.