• Title/Summary/Keyword: learning study

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The impact of functional brain change by transcranial direct current stimulation effects concerning circadian rhythm and chronotype (일주기 리듬과 일주기 유형이 경두개 직류전기자극에 의한 뇌기능 변화에 미치는 영향 탐색)

  • Jung, Dawoon;Yoo, Soomin;Lee, Hyunsoo;Han, Sanghoon
    • Korean Journal of Cognitive Science
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    • v.33 no.1
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    • pp.51-75
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    • 2022
  • Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation that is able to alter neuronal activity in particular brain regions. Many studies have researched how tDCS modulates neuronal activity and reorganizes neural networks. However it is difficult to conclude the effect of brain stimulation because the studies are heterogeneous with respect to the stimulation parameter as well as individual difference. It is not fully in agreement with the effects of brain stimulation. In particular few studies have researched the reason of variability of brain stimulation in response to time so far. The study investigated individual variability of brain stimulation based on circadian rhythm and chronotype. Participants were divided into two groups which are morning type and evening type. The experiment was conducted by Zoom meeting which is video meeting programs. Participants were sent experiment tool which are Muse(EEG device), tdcs device, cell phone and cell phone holder after manuals for experimental equipment were explained. Participants were required to make a phone in frount of a camera so that experimenter can monitor online EEG data. Two participants who was difficult to use experimental devices experimented in a laboratory setting where experimenter set up devices. For all participants the accuracy of 98% was achieved by SVM using leave one out cross validation in classification in the the effects of morning stimulation and the evening stimulation. For morning type, the accuracy of 92% and 96% was achieved in classification in the morning stimulation and the evening stimulation. For evening type, it was 94% accuracy in classification for the effect of brain stimulation in the morning and the evening. Feature importance was different both in classification in the morning stimulation and the evening stimulation for morning type and evening type. Results indicated that the effect of brain stimulation can be explained with brain state and trait. Our study results noted that the tDCS protocol for target state is manipulated by individual differences as well as target state.

High School Student Perception of the Relationships between Solar and Visible Radiation and between Terrestrial and Infrared Radiation (태양 복사와 가시광선 복사 및 지구 복사와 적외선 복사의 관계에 대한 고등학생들의 인식)

  • Lee, Jong-Jin;Seo, Eun-Kyoung;Ahn, Yumin
    • Journal of the Korean earth science society
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    • v.43 no.2
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    • pp.312-323
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    • 2022
  • This study began with the hypothesis of whether "solar radiation" and "terrestrial radiation" can be replaced by "visible radiation" and "infrared radiation", respectively. To this end, we investigated the perceptions of high school students who completed the Earth Science I course through a questionnaire to reveal how they perceived each concept. We also analyzed the descriptions and illustrations of textbooks that may have affected their perceptions. All of the students who participated in the questionnaire recognized solar radiation as radiation emitted only in the visible light region. About 35% of the students recognized convection, conduction, and latent heat as energy transfer by radiation in the Earth's heat budget. By analyzing six types of Earth Science I textbooks in the 2015 revised curriculum, we observed that two types introduced the terms "shortwave radiation" and "longwave radiation" but had no explanation for them, while the other two described solar radiation as "radiation mainly in the visible light region" or "radiation in short wavelengths". Regarding solar and terrestrial radiation in the last two types, there was no explanation for the wavelength regions, or ambiguous terms such as "short wavelength" and "long wavelength" were used. In addition, the two textbooks contained some errors in the illustration of the energy budget. Considering that textbooks described solar and terrestrial radiation without defining the exact terms for shortwave and longwave radiation, learners are likely to recognize solar and terrestrial radiation as visible and infrared radiation, respectively. This finding implies that vague statements or errors in textbooks can cause or reproduce students' misconceptions. The discussion in this study is expected to be used as a helpful reference material for teaching and learning processes regarding the Earth's radiation equilibrium and heat budget, and thereby contribute to proposing reasonable description plans for future textbook writing.

A Study on the Art Education Program Based on Cultural Diversity: Focused on the Case of National Museum of Modern and Contemporary Art, Korea (서울어젠다 기반 문화다양성 미술관교육 프로그램 분석 및 방향 - 국립현대미술관 사례를 중심으로 -)

The Practice of 'Liberated-ness': An Education Model for Protestant Spiritual Practice (개신교 '자유케 됨'의 영성에 기초한 기독교 영성교육 모형: '자유케 됨'의 실천)

  • Hwang, In-Hae
    • Journal of Christian Education in Korea
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    • v.68
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    • pp.375-415
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    • 2021
  • Although the interest in Christian education of spirituality has increased recently, the practice of the education of spirituality in the Korean Church has been fragmented in the contents and methods without any clear educational purpose of the Protestant tradition. This requires a creative study to seek out the contents and method best suited to realizing the educational purpose of the Protestant tradition, through a rigorous academic methodology. This study proposes just such a creative model for the education of spirituality with an educational purpose based on the core ethos of the Protestant spirituality, integrating the long tradition of spiritual practices of Christianity. First, I survey the teachings on 'the life of faith' of the main leaders of the Protestant church, including Martin Luther, John Calvin, and John Wesley. Through this process, I reveal 'liberated-ness' to be the common purpose of the Protestant leaders, and the core of the practices for that purpose are 'the means of grace,' which has a different meaning from that of the Roman Catholic tradition. I construct the meaning of 'liberated-ness' in a dynamic manner, which begins with the 'liberating will' of God, and is followed by the 'self-giving will' of the believer as the response to the 'grace' of the 'liberating will.' The contact point of these two 'wills' is what I call 'the living membrane of faith.' As a creative synthesis of the above discussions, I propose a model of 'the practice of liberated-ness' for an education in spiritual practice. The purpose of this education is for the learner to become a person who continuously experiences ever-increasing 'liberated-ness' through continuous personal 'encounters' with God, and to become ever more faithful in carrying out practices for the 'liberated-ness' of her or his neighbors. The relationship between the teacher and the learner is that of personal 'encounter' as put forth by Sherrill, and also incorporates elements of 'co-authorship' as conceptualized by Kim. I transform and rename major practices of spiritual discipline according to a principle of 'liberated-ness' based on the Protestant tradition, and these comprise the main content of my spirituality education model. They include: 'lectio divina of encounter,' 'prayer facing the Lord,' 'service in liberation,' 'reflection of liberated-ness,' and 'mutual spiritual direction.' The teaching and learning process draws on Dykstra's methods of coaching and mentoring. The key environment is that of a 'sacramental community' as defined by Moore. Evaluation can be performed only by the learner her/himself. The significance of this model is that it creatively inherits and succeeds the tradition of Christian spiritual discipline from the early church onwards by transforming it through a Protestant spirituality of 'liberated-ness.'

Automated Analyses of Ground-Penetrating Radar Images to Determine Spatial Distribution of Buried Cultural Heritage (매장 문화재 공간 분포 결정을 위한 지하투과레이더 영상 분석 자동화 기법 탐색)

  • Kwon, Moonhee;Kim, Seung-Sep
    • Economic and Environmental Geology
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    • v.55 no.5
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    • pp.551-561
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    • 2022
  • Geophysical exploration methods are very useful for generating high-resolution images of underground structures, and such methods can be applied to investigation of buried cultural properties and for determining their exact locations. In this study, image feature extraction and image segmentation methods were applied to automatically distinguish the structures of buried relics from the high-resolution ground-penetrating radar (GPR) images obtained at the center of Silla Kingdom, Gyeongju, South Korea. The major purpose for image feature extraction analyses is identifying the circular features from building remains and the linear features from ancient roads and fences. Feature extraction is implemented by applying the Canny edge detection and Hough transform algorithms. We applied the Hough transforms to the edge image resulted from the Canny algorithm in order to determine the locations the target features. However, the Hough transform requires different parameter settings for each survey sector. As for image segmentation, we applied the connected element labeling algorithm and object-based image analysis using Orfeo Toolbox (OTB) in QGIS. The connected components labeled image shows the signals associated with the target buried relics are effectively connected and labeled. However, we often find multiple labels are assigned to a single structure on the given GPR data. Object-based image analysis was conducted by using a Large-Scale Mean-Shift (LSMS) image segmentation. In this analysis, a vector layer containing pixel values for each segmented polygon was estimated first and then used to build a train-validation dataset by assigning the polygons to one class associated with the buried relics and another class for the background field. With the Random Forest Classifier, we find that the polygons on the LSMS image segmentation layer can be successfully classified into the polygons of the buried relics and those of the background. Thus, we propose that these automatic classification methods applied to the GPR images of buried cultural heritage in this study can be useful to obtain consistent analyses results for planning excavation processes.

An Analysis on Landscape Architecture in Korean Seowon from 16th to 19th Century and its Historic Significance (조선 시대 서원 조경의 특징과 역사적 의미 연구)

  • Lee, Younghoon-Hayden;Sung, Jong-Sang
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.2
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    • pp.1-10
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    • 2023
  • This study aims to explore the significance of historic changes and cultural characteristics of landscape architecture in Korean Seowon. Seowon refers to educational private institutes that also served as Confucian shrines and were prevalent during the mid-to-late Joseon dynasty. Seowon comprised three distinct functional spaces: a shrine, a school, and a garden. The concept of Seowon's garden extended beyond designed landscapes to include the surrounding natural environment. The importance of landscape architecture in Seowon is rooted in its connection to the educational philosophy of these institutes. During the Joseon dynasty, scholars revered nature as a manifestation of Confucian ideals, and they believed that close engagement with nature was integral to self-discipline and learning. This research investigated fifteen relatively well-preserved garden in South Korea and conducted a comprehensive analysis of their gardens. The analysis revealed two key findings. Firstly, gardens in Seowon were actively designed and constructed during the early phase of Seowon culture but gradually diminished after the 17th century. This can be attributed to the shift in Seowon's purpose, with a greater emphasis on its religious function over education. Consequently, the significance and presence of landscape architecture in Seowon, which was closely related with its Confucianist education, declined. Secondly, the study explored the historical backgrounds of each Seowon's landscape architecture and found that many of them were designed or influenced by individuals who were later memorialized and deified in the Seowon's shrines. The landscape architecture created by these predecessors was carefully preserved by the faculties and students as a form of respect. Therefore, landscape architecture in Korean Seowon not only conveys the institutional purpose as an educational hub for the local society but also reflects the institute's strong relationship with the figures they worship as shrines.

A study on the scientific background of thinking of Kang Youwei and a stage of 'Tianyou' (강유위(康有爲) 사상의 과학적 배경과 '천유경계(天遊境界)')

  • Han, Sung Gu
    • The Journal of Korean Philosophical History
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    • no.27
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    • pp.197-222
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    • 2009
  • The Reform Movement(戊戌變法) of 1898 was a boundary tablet of modern history of science and technology which inherited the past and ushered in the future. Kang Youwei(康有爲), as a leader, his scientific thoughts opened up the way of Chinese enlightenity campaign and pushed the development of Chinese modem science and had an important position in modem history of scientific thoughts. The dissertation analyses the source, establishment and content of Kang Youwei. Kang Youwei developed the useful and discarded the useless of the view of implement science held by the Westernized Party, undertook a deep and throughout thinking on the nature of science, had cognition of scientific methods and spirit, by which he criticized negative proneness of ancient Chinese views of science. He put forwards a series of practical suggestions on political reform that provided a solid guarantee and support in system for scientific development. Kang Youwei rooted in the soil of Chinese traditional academic culture, but also western learning in modern western civilization. Kang go through Westernization Movement since the in-depth study of Western natural and inevitable outcome of the social sciences, are giving to science and technology. Although he was originally of Western "science" has a lot of misunderstandings and prejudices, but these shallow hazy perceptual knowledge, his view of science which constitutes the basis of the formation. In the course of scientific inquiry, Kang has begun to explore the essence of scientific development. He has a gut feeling that behind the scientific discovery of the existence of a force, which is the scientific truth and is used to grasp the scientific method. After contact with the Western world, with the traditional "Heaven(天)", and modern Chinese intellectuals began to "axiom(公理)" to recover his traditional "Heaven" of the new understanding is reflected mainly in "Zhutianjiang(諸天講)". "Zhutianjiang" is the Kang Yuwei in the absorption of traditional astronomy knowledge base, will the traditional arithmetic, as well as Buddhism and the West since the twentieth century, new knowledge of astronomy combines written. Kang while recognizing that scientific instruments, is nothing more than an extension of the role of the human senses and make the "Dao(道)" is more clear, but the "artifacts(器物)" caused by the inherent limitations of the limited nature of human knowledge, which is "Heaven" boundless nature of the broad terms, refused to concede defeat to. In reality, the activities of political reform, he gradually recognize this real-world helpless, and he recognized that the real world to achieve common ground of social ideal is impossible, so he chose comfort in life that people really get a stage of "Tianyou(天遊)". This is the cause that his writing "Datongshu(大同書)", at the same time, followed by writing "Zhutianjiang" talk "Tianyou".

Application of spatiotemporal transformer model to improve prediction performance of particulate matter concentration (미세먼지 예측 성능 개선을 위한 시공간 트랜스포머 모델의 적용)

  • Kim, Youngkwang;Kim, Bokju;Ahn, SungMahn
    • Journal of Intelligence and Information Systems
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    • v.28 no.1
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    • pp.329-352
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    • 2022
  • It is reported that particulate matter(PM) penetrates the lungs and blood vessels and causes various heart diseases and respiratory diseases such as lung cancer. The subway is a means of transportation used by an average of 10 million people a day, and although it is important to create a clean and comfortable environment, the level of particulate matter pollution is shown to be high. It is because the subways run through an underground tunnel and the particulate matter trapped in the tunnel moves to the underground station due to the train wind. The Ministry of Environment and the Seoul Metropolitan Government are making various efforts to reduce PM concentration by establishing measures to improve air quality at underground stations. The smart air quality management system is a system that manages air quality in advance by collecting air quality data, analyzing and predicting the PM concentration. The prediction model of the PM concentration is an important component of this system. Various studies on time series data prediction are being conducted, but in relation to the PM prediction in subway stations, it is limited to statistical or recurrent neural network-based deep learning model researches. Therefore, in this study, we propose four transformer-based models including spatiotemporal transformers. As a result of performing PM concentration prediction experiments in the waiting rooms of subway stations in Seoul, it was confirmed that the performance of the transformer-based models was superior to that of the existing ARIMA, LSTM, and Seq2Seq models. Among the transformer-based models, the performance of the spatiotemporal transformers was the best. The smart air quality management system operated through data-based prediction becomes more effective and energy efficient as the accuracy of PM prediction improves. The results of this study are expected to contribute to the efficient operation of the smart air quality management system.

Vegetation classification based on remote sensing data for river management (하천 관리를 위한 원격탐사 자료 기반 식생 분류 기법)

  • Lee, Chanjoo;Rogers, Christine;Geerling, Gertjan;Pennin, Ellis
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.6-7
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    • 2021
  • Vegetation development in rivers is one of the important issues not only in academic fields such as geomorphology, ecology, hydraulics, etc., but also in river management practices. The problem of river vegetation is directly connected to the harmony of conflicting values of flood management and ecosystem conservation. In Korea, since the 2000s, the issue of river vegetation and land formation has been continuously raised under various conditions, such as the regulating rivers downstream of the dams, the small eutrophicated tributary rivers, and the floodplain sites for the four major river projects. In this background, this study proposes a method for classifying the distribution of vegetation in rivers based on remote sensing data, and presents the results of applying this to the Naeseong Stream. The Naeseong Stream is a representative example of the river landscape that has changed due to vegetation development from 2014 to the latest. The remote sensing data used in the study are images of Sentinel 1 and 2 satellites, which is operated by the European Aerospace Administration (ESA), and provided by Google Earth Engine. For the ground truth, manually classified dataset on the surface of the Naeseong Stream in 2016 were used, where the area is divided into eight types including water, sand and herbaceous and woody vegetation. The classification method used a random forest classification technique, one of the machine learning algorithms. 1,000 samples were extracted from 10 pre-selected polygon regions, each half of them were used as training and verification data. The accuracy based on the verification data was found to be 82~85%. The model established through training was also applied to images from 2016 to 2020, and the process of changes in vegetation zones according to the year was presented. The technical limitations and improvement measures of this paper were considered. By providing quantitative information of the vegetation distribution, this technique is expected to be useful in practical management of vegetation such as thinning and rejuvenation of river vegetation as well as technical fields such as flood level calculation and flow-vegetation coupled modeling in rivers.

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Prediction of Spring Flowering Timing in Forested Area in 2023 (산림지역에서의 2023년 봄철 꽃나무 개화시기 예측)

  • Jihee Seo;Sukyung Kim;Hyun Seok Kim;Junghwa Chun;Myoungsoo Won;Keunchang Jang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.4
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    • pp.427-435
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    • 2023
  • Changes in flowering time due to weather fluctuations impact plant growth and ecosystem dynamics. Accurate prediction of flowering timing is crucial for effective forest ecosystem management. This study uses a process-based model to predict flowering timing in 2023 for five major tree species in Korean forests. Models are developed based on nine years (2009-2017) of flowering data for Abeliophyllum distichum, Robinia pseudoacacia, Rhododendron schlippenbachii, Rhododendron yedoense f. poukhanense, and Sorbus commixta, distributed across 28 regions in the country, including mountains. Weather data from the Automatic Mountain Meteorology Observation System (AMOS) and the Korea Meteorological Administration (KMA) are utilized as inputs for the models. The Single Triangle Degree Days (STDD) and Growing Degree Days (GDD) models, known for their superior performance, are employed to predict flowering dates. Daily temperature readings at a 1 km spatial resolution are obtained by merging AMOS and KMA data. To improve prediction accuracy nationwide, random forest machine learning is used to generate region-specific correction coefficients. Applying these coefficients results in minimal prediction errors, particularly for Abeliophyllum distichum, Robinia pseudoacacia, and Rhododendron schlippenbachii, with root mean square errors (RMSEs) of 1.2, 0.6, and 1.2 days, respectively. Model performance is evaluated using ten random sampling tests per species, selecting the model with the highest R2. The models with applied correction coefficients achieve R2 values ranging from 0.07 to 0.7, except for Sorbus commixta, and exhibit a final explanatory power of 0.75-0.9. This study provides valuable insights into seasonal changes in plant phenology, aiding in identifying honey harvesting seasons affected by abnormal weather conditions, such as those of Robinia pseudoacacia. Detailed information on flowering timing for various plant species and regions enhances understanding of the climate-plant phenology relationship.