• Toxicological Research
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• 제17권
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• pp.257-261
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• 2001

Recently, a traditional medicine called Gouteng-san, which consists of eleven herbs, was reported to be effective in treating vascular dementia with a double-blind, placebo-controlled study. Gout-eng-san is also used for patients with vascular dementia in combination with Si-Wu-Tang. The effect of Gouteng-san and Si-Wu-Tang on deficit of learning behavior was investigated using step-down passive avoidance task in mice. Hot-water extract of Gouteng-san (1.5 and 6 g/kg, p.o.) significantly prolonged the step-down latency shortened by scopolamine. The extract of Uncaria hook (150 mg/kg, p.o.), one of the component herb of Gouteng-san, significantly prevented the decrease in the latency after scopolamine. Hot-water extract of Si-Wu-Tang (1.5 and 6 g/kg of dried herbs, p.o.) prevented dose-dependently scopola-mine-induced disruption qf learning behavior. Si-Wu-Tang also prevented the ischemia-induced deficit of learning behavior. Both hot water extract of peony and angelica (1.5 g/kg, p.o.), which are component herbs qf Si-Wu-Tang, prevented the scopolamine-induced learning behavior deficit. Scopolamine (10 uM) suppressed long-term potentiation (LTP) of population spike in the CA1 region of the rat hippocampal slices. Peoniflorin (0.1~ 1uM) extracted from paeony root significantly ameliorated scopolamine-induced inhibition of LTR These results suggest that improvement of deficit of learning behavior by Gouteng-san and Si-Wu-Tang is mediated by direct and/or indirect activation of the cholinergic system in the brain.

• Geomechanics and Engineering
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• 제25권1호
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• pp.59-73
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• 2021

There frequently exists inadequacy regarding the number of boreholes installed along tunnel alignment. While geophysical imaging techniques are available for pre-tunnelling geological characterization, they aim to detect specific object (e.g., water body and karst cave). There remains great motivation for the industry to develop a real-time identification technology relating complex geological conditions with the existing tunnelling parameters. This study explores the potential for the use of machine learning-based data driven approaches to identify the change in geology during tunnel excavation. Further, the feasibility for machine learning-based anomaly detection approaches to detect the development of clayey clogging is also assessed. The results of an application of the machine learning-based approaches to Xi'an Metro line 4 are presented in this paper where two tunnels buried in the water-rich sandy soils at depths of 12-14 m are excavated using a 6.288 m diameter EPB shield machine. A reasonable agreement with the measurements verifies their applicability towards widening the application horizon of machine learning-based approaches.

• Wind and Structures
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• 제36권6호
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• pp.367-377
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• 2023

This study proposes a few-shot learning model for extrapolating the wind pressure of scaled experiments to full-scale measurements. The proposed ML model can use scaled experimental data and a few full-scale tests to accurately predict the remaining full-scale data points (for new specimens). This model focuses on extrapolating the prediction to different scales while existing approaches are not capable of accurately extrapolating from scaled data to full-scale data in the wind engineering domain. Also, the scaling issue observed in wind tunnel tests can be partially resolved via the proposed approach. The proposed model obtained a low mean-squared error and a high coefficient of determination for the mean and standard deviation wind pressure coefficients of the full-scale dataset. A parametric study is carried out to investigate the influence of the number of selected shots. This technique is the first of its kind as it is the first time an ML model has been used in the wind engineering field to deal with extrapolation in wind performance prediction. With the advantages of the few-shot learning model, physical wind tunnel experiments can be reduced to a great extent. The few-shot learning model yields a robust, efficient, and accurate alternative to extrapolating the prediction performance of structures from various model scales to full-scale.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2023년도 추계학술대회
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• pp.230-231
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• 2023

본 연구는 선박의 항해계획을 자동으로 수립하기 위한 심층 강화학습 기반 알고리즘을 제안한다. 먼저 부산항과 광양항을 대상지역으로 선정하고, 대상 선박으로 흘수 16m의 컨테이너선을 지정하였다. 실험 결과는 심층 강화학습을 사용하여 수립한 항해계획이 선행연구에서 활용한 Q-learning기반의 알고리즘보다 더 효율적인 것으로 분석되었다. 본 알고리즘은 선박의 항해계획을 자동으로 수립하는 방법을 제시하며, 해상 안전 및 효율성 향상에 기여할 수 있다.

• 시스템엔지니어링학술지
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• 제20권spc1호
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• pp.90-96
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• 2024

In this paper, we propose a technique to model high resolution seafloor topography with 1m intervals using actual water depth data near the east coast of the Korea with 1.6km distance intervals. Using a feature point extraction algorithm that harris corner based on deep learning, the location of the center of seafloor mountain was calculated and the surrounding topology was modeled. The modeled high-resolution seafloor topography based on deep learning was verified within 1.1m mean error between the actual warder dept data. And average error that result of calculating based on deep learning was reduced by 54.4% compared to the case that deep learning was not applied. The proposed algorithm is expected to generate high resolution underwater topology for the entire Korean peninsula and be used to establish a path plan for autonomous navigation of underwater vehicle.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2015년도 제51차 동계학술대회논문집 23권1호
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• pp.329-330
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• 2015

최근 한류의 유행과 결혼 이주여성 등의 증가로 인해 다양한 첨단 미디어를 통하여 세계 각국에서 외국어로서의 한국어를 배우려는 학습자의 수가 증가하고 있다. 교수자와 학습자간의 교육환경은 다양한 학습미디어의 발전에 따라 학습자가 수동적인 자세에서 벗어나 능동적인 학습 방법으로 진화되고 있다. 특히 다양한 멀티미디어 기기와 관련 기술들의 발전은 기존의 교육방법론적 환경에서 벗어나, 새로운 기술에 기반을 둔 학습자 중심의 교육방법의 개선과 제시에는 현실적으로 고려해야하는 여러 사항과 문제점이 존재한다. 따라서 이 논문에서는 최신 기술에 기반을 둔 모바일을 이용한 엠러닝(M-Learning) 기반의 한국어교육 콘텐츠관리를 위한 시스템을 제안하고자 한다.

• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.61-72
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• 2020

Recently, researches that are using deep learning technology in various fields are being conducted. The fields include geographic map processing. In this paper, I propose a method to infer where the map area included in the image is. The proposed method generates and learns images including a map, detects map areas from input images, extracts character strings belonging to those map areas, and converts the extracted character strings into coordinates through geocoding to infer the coordinates of the input image. Faster R-CNN was used for learning and map detection. In the experiment, the difference between the center coordinate of the map on the test image and the center coordinate of the detected map is calculated. The median value of the results of the experiment is 0.00158 for longitude and 0.00090 for latitude. In terms of distance, the difference is 141m in the east-west direction and 100m in the north-south direction.

• 한국시뮬레이션학회논문지
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• 제21권4호
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• pp.65-73
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• 2012

함정 전투체계는 무기체계, 정보통신 등의 기술 발전으로 인한 복잡한 전장 환경에 따라 인간이 개입하여 다양한 전술을 운용해야 한다. 따라서 에이전트 기반의 국방 M&S 시스템의 연구가 최근 들어 활발히 진행되고 있다. 그러나 현존하는 에이전트 기반 M&S 시스템은 고정된 전술을 적용하여 분석하는데 그치고 있다. 본 논문에서는 함정 교전에서 보다 적합한 대응을 찾기 위해 환경변화에 능동적으로 대처할 수 있도록 강화 학습 기능을 갖으며, 또한 유전 알고리즘을 이용하여 세대별 진화 학습 기능을 갖는 에이전트 모델링 방법론을 제안하였다. 타당성 검증을 위해 서해상에서 벌어지는 가상의 1:1 함정교전 시뮬레이션을 수행하였고, 이를 통해 함정 교전에 있어 강화 및 진화 학습이 가능함을 검증하였다.

• Psychiatry investigation
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• 제15권12호
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• pp.1144-1153
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• 2018

Objective One of the areas of social cognition is Theory of Mind (ToM) is defined as the capacity to interpret, infer and explain mental states underlying the behavior of others. When social cognition studies on neurodevelopmental disorders are examined, it can be seen that this skill has not been studied sufficiently in children with Specific Learning Disorder (SLD). Methods In this study, social cognition skills in children diagnosed with attention deficit hyperactivity disorder (ADHD), SLD or Autism Spectrum Disorder (ASD) evaluated before puberty and compared with controls. To evaluate the ToM skills, the first and second-order false belief tasks, the Hinting Task, the Faux Pas Test and the Reading the Mind in the Eyes Task were used. Results We found that children with neurodevelopmental disorders as ADHD, ASD, and SLD had ToM deficits independent of intelligence and language development. There was a significant correlation between social cognition deficits and problems experienced in many areas such as social communication and interaction, attention, behavior, and learning. Conclusion Social cognition is an important area of impairment in SLD and there is a strong relationship between clinical symptoms and impaired functionality.

• Advances in concrete construction
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• 제14권1호
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• pp.15-34
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• 2022

The use of waste rubber in concrete can reduce natural aggregate consumption and improve some technical properties of concrete. Although there are several equations for estimating the mechanical properties of concrete containing waste rubber, limited numbers of machine learning-based models have been proposed to predict the mechanical properties of rubbercrete. In this study, an extensive database of the mechanical properties of rubbercrete was gathered from a comprehensive survey of the literature. To model the mechanical properties of rubbercrete, M5P tree and linear gene expression programming (LGEP) methods as two machine learning techniques were employed to achieve reliable mathematical equations. Two procedures of input variable selection were considered in this study. The crucial component ratios of rubbercrete and concrete age were assumed as the input variables in the first procedure. In contrast, the volumes of the coarse and fine waste rubber and the compressive strength of concrete without waste rubber were considered the second procedure of the input variables. The results show that the models obtained by LGEP are more accurate than those achieved by the M5P model tree and existing traditional equations. Besides, the volumes of the coarse and fine waste rubber and the compressive strength of concrete without waste rubber are better predictors of the mechanical properties of rubbercrete compared to the first procedure of input variable selection.