• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.693-696
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• 2021

강화학습에는 다양한 알고리즘이 있으며 분야에 따라 사용되는 알고리즘이 다르다. 게임 분야에서도 강화학습을 사용하여 인공지능을 개발할 때 특정 알고리즘이 사용된다. 알고리즘에 따라 학습 방식이 다르고 그로 인해 만들어지는 인공지능도 달라진다. 그러므로 개발자는 목적에 맞는 인공지능을 구현하기 위해 적절한 알고리즘을 선택해야 한다. 그러기 위해서 개발자는 알고리즘의 학습 방식과 어떤 종류의 인공지능 구현에 적용되는 것이 효율적인지 알고 있어야 한다. 따라서 이 논문에서는 게임 인공지능 구현에 사용되는 알고리즘인 SAC, PPO, POCA 세 가지 알고리즘의 학습 방식과 어떤 종류의 인공지능 구현에 적용되는 것이 효율적인지 비교한다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제10권3호
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• pp.170-177
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• 2010

Poker is a game of imperfect information where competing players must deal with multiple risk factors stemming from unknown information while making the best decision to win, and this makes it an interesting test-bed for artificial intelligence research. This paper introduces a new learning AI algorithm with embedded opponent modeling that can be used for these types of situations and we use this AI and apply it to a poker program. The new AI will be based on several graphs with each of its nodes representing inputs, and the algorithm will learn the optimal decision to make by updating the weight of the edges connecting these nodes and returning a probability for each action the graphs represent.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.1989-2001
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• 2024

Artificial intelligence (AI) techniques are now being considered in the nuclear field, but application faces with the lack of actual plant data. For this reason, most previous studies on AI applications in nuclear power plants (NPPs) have relied on simulators or thermal-hydraulic codes to mimic the plants. However, it remains uncertain whether an AI model trained using a simulator can properly work in an actual NPP. To address this issue, this study suggests the use of metadata, which can give information about parameter trends. Referred to here as robust AI, this concept started with the idea that although the absolute value of a plant parameter differs between a simulator and actual NPP, the parameter trend is identical under the same scenario. Based on the proposed robust AI, this study designs an event diagnosis algorithm to classify abnormal and emergency scenarios in NPPs using prototypical learning. The algorithm was trained using a simulator referencing a Westinghouse 990 MWe reactor and then tested in different environments in Advanced Power Reactor 1400 MWe simulators. The algorithm demonstrated robustness with 100 % diagnostic accuracy (117 out of 117 scenarios). This indicates the potential of the robust AI-based algorithm to be used in actual plants.

• 대한임베디드공학회논문지
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• 제19권3호
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• pp.151-158
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• 2024

Although on-device artificial intelligence (AI) has gained attention to diagnosing machine faults in real time, most previous studies did not consider the model retraining and redeployment processes that must be performed in real-world industrial environments. Our study addresses this challenge by proposing an on-device AI-based real-time machine fault diagnosis system that utilizes continual learning. Our proposed system includes a lightweight convolutional neural network (CNN) model, a continual learning algorithm, and a real-time monitoring service. First, we developed a lightweight 1D CNN model to reduce the cost of model deployment and enable real-time inference on the target edge device with limited computing resources. We then compared the performance of five continual learning algorithms with three public bearing fault datasets and selected the most effective algorithm for our system. Finally, we implemented a real-time monitoring service using an open-source data visualization framework. In the performance comparison results between continual learning algorithms, we found that the replay-based algorithms outperformed the regularization-based algorithms, and the experience replay (ER) algorithm had the best diagnostic accuracy. We further tuned the number and length of data samples used for a memory buffer of the ER algorithm to maximize its performance. We confirmed that the performance of the ER algorithm becomes higher when a longer data length is used. Consequently, the proposed system showed an accuracy of 98.7%, while only 16.5% of the previous data was stored in memory buffer. Our lightweight CNN model was also able to diagnose a fault type of one data sample within 3.76 ms on the Raspberry Pi 4B device.

• 정보교육학회논문지
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• 제24권5호
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• pp.495-509
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• 2020

본 연구는 인공지능(이하 AI)이 모든 영역에 전일적으로 확산되는 시점을 맞아 비전공자들도 AI를 효과적으로 학습하는 방안을 탐색하기 위한 하나의 시론적 연구이다. AI 교육을 수학, 통계, 컴퓨터공학 전공 학생들뿐만 아니라 인문·사회과학 등 다른 전공자들도 쉽게 접근할 수 있도록 하기 위한 학습법을 탐색하고자 하였다. 마침 '설명 가능한 AI(XAI: eXplainable AI)'의 필요성과 MIT AI 연구소의 Patrick Winston의 '지각 있는 기계(AI)를 위한 스토리텔링의 중요성[33]'이 두드러진 상황에서 AI 스토리텔링 학습모델 연구의 의의를 찾을 수 있겠다. 이를 위해 본 연구는 우선 대구 소재 A 대학교의 학생들을 대상으로 그 가능성을 테스트하였다. 먼저 AI 스토리텔링(AI+ST) 학습법[30]의 교육목표, AI 교육내용의 체계와 학습방법론, 새로운 AI 도구의 소개 및 활용에 대해 살펴보고, 1) AI+ST 학습법이 알고리즘 중심의 학습법을 보완할 수 있는지, 2) AI+ST 학습법이 학생들에게도 효과가 있는지, 그리하여 AI 이해력, 흥미도, 응용력 배양에 도움이 되었는지에 관한 연구 질문을 중심으로 학습자들의 결과물을 비교 분석하였다.

• Clinical Endoscopy
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• 제55권5호
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• pp.594-604
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• 2022

Over the past decade, technological advances in deep learning have led to the introduction of artificial intelligence (AI) in medical imaging. The most commonly used structure in image recognition is the convolutional neural network, which mimics the action of the human visual cortex. The applications of AI in gastrointestinal endoscopy are diverse. Computer-aided diagnosis has achieved remarkable outcomes with recent improvements in machine-learning techniques and advances in computer performance. Despite some hurdles, the implementation of AI-assisted clinical practice is expected to aid endoscopists in real-time decision-making. In this summary, we reviewed state-of-the-art AI in the field of gastrointestinal endoscopy and offered a practical guide for building a learning image dataset for algorithm development.

• 한국빅데이터학회지
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• 제7권1호
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• pp.1-14
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• 2022

대부분의 블록체인이 사용하는 작업증명 합의 알고리즘은 채굴이라는 형태로 대규모의 컴퓨팅리소스 낭비를 초래하고 있다. 작업증명의 컴퓨팅리소스 낭비를 줄이기 위해 유용한 작업증명 합의 알고리즘이 연구 되었으나 여전히 블록 생성 시 리소스 낭비와 채굴의 중앙화 문제가 존재한다. 본 논문에서는 블록생성을 위한 상대적으로 비효율적인 연산 과정을 분산 인공지능 모델 학습으로 대체하여 블록생성 시 리소스 낭비문제를 해결하였다. 또한 학습 과정에 참여한 노드들에게 공평한 보상을 제공함으로써 컴퓨팅파워가 약한 노드의 참여 동기를 부여했고, 기존 중앙 집중 인공지능 학습 방식에 근사한 성능은 유지하였다. 제안된 방법론의 타당성을 보이기 위해 분산 인공지능 학습이 가능한 블록체인 네트워크를 구현하여 리소스 검증을 통한 보상 분배를 실험 하였고, 기존 중앙 학습 방식과 블록체인 분산 인공지능 학습 방식의 결과를 비교하였다. 또한 향후 연구로 블록체인 메인넷과 인공지능 모델 확장 시 발생 할 수 있는 문제점과 개발 방향성을 제시함으로서 논문을 마무리 하였다.

• 드라이브 ㆍ 컨트롤
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• 제18권1호
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• pp.24-30
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• 2021

There is an increasing interest in condition-based maintenance for the prevention of economic loss due to failure. Moreover, immense research is being carried out in related technologies in the field of construction machinery. In particular, data-based failure diagnosis methods that employ AI (machine & deep learning) algorithms are in the spotlight. In this study, we have focused on the failure diagnosis and mode classification of reduction gear of excavator's travel device by using the AI algorithm. In addition, a remote monitoring system has been developed that can monitor the status of the reduction gear by using the developed diagnosis algorithm. The failure diagnosis algorithm was performed in the process of data acquisition of normal and abnormal under various operating conditions, data processing and analysis by the wavelet transformation, and learning. The developed algorithm was verified based on three-evaluation conditions. Finally, we have built a system that can check the status of the reduction gear of travel devices on the web using the Edge platform, which is embedded with the failure diagnosis algorithm and cloud.

• 한국군사과학기술학회지
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• 제27권2호
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• pp.256-264
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• 2024

In the last 10 years, AI has made rapid progress, and image classification, in particular, are showing excellent performance based on deep learning. Nevertheless, due to the nature of deep learning represented by a black box, it is difficult to actually use it in critical decision-making situations such as national defense, autonomous driving, medical care, and finance due to the lack of explainability of judgement results. In order to overcome these limitations, in this study, a model description algorithm capable of local interpretation was applied to the inception network-derived AI to analyze what grounds they made when classifying national defense data. Specifically, we conduct a comparative analysis of explainability based on confidence values by performing LIME analysis from the Inception v2_resnet model and verify the similarity between human interpretations and LIME explanations. Furthermore, by comparing the LIME explanation results through the Top1 output results for Inception v3, Inception v2_resnet, and Xception models, we confirm the feasibility of comparing the efficiency and availability of deep learning networks using XAI.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.223-224
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• 2021

The process before the model learning stage in AI R&D can be subdivided into data collection/cleansing-data purification-data labeling. After that, according to the purpose of development, it goes through a stage of verifying the model by performing learning by using the algorithm of the artificial intelligence model. Several studies describe an important part of AI research as the learning stage, and try to increase the accuracy by changing the structure and layer of the AI model. However, if the refinement and labeling process of the learning data is tailored only to the model format and is not made for the purpose of development, the desired AI model cannot be obtained. The latest research reveals that most AI research failures are the failure of the learning data rather than the structure of the AI model. analyzed.