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Three body problem in early 20th century (20세기초의 삼체문제에 관해서)

  • Lee, Ho Joong
    • Journal for History of Mathematics
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    • v.25 no.4
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    • pp.53-67
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    • 2012
  • Today, it is necessary to calculate orbits with high accuracy in space flight. The key words of Poincar$\acute{e}$ in celestial mechanics are periodic solutions, invariant integrals, asymptotic solutions, characteristic exponents and the non existence of new single-valued integrals. Poincar$\acute{e}$ define an invariant integral of the system as the form which maintains a constant value at all time $t$, where the integration is taken over the arc of a curve and $Y_i$ are some functions of $x$, and extend 2 dimension and 3 dimension. Eigenvalues are classified as the form of trajectories, as corresponding to nodes, foci, saddle points and center. In periodic solutions, the stability of periodic solutions is dependent on the properties of their characteristic exponents. Poincar$\acute{e}$ called bifurcation that is the possibility of existence of chaotic orbit in planetary motion. Existence of near exceptional trajectories as Hadamard's accounts, says that there are probabilistic orbits. In this context we study the eigenvalue problem in early 20th century in three body problem by analyzing the works of Darwin, Bruns, Gyld$\acute{e}$n, Sundman, Hill, Lyapunov, Birkhoff, Painlev$\acute{e}$ and Hadamard.

A Study of Diaphoretic Therapy[汗法] in "Yumunsachin(儒門事親)" ("유문사친(儒門事親)"의 '한법(汗法)'에 관한 연구)

  • Kim, Ki-Wook;Park, Hyun-Kuk;Jung, Kyung-Ho
    • Journal of Korean Medical classics
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    • v.21 no.1
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    • pp.1-11
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    • 2008
  • Jangjahwa(張子和) was influenced by "Hwangjenaegyeong(黃帝內經)" and Yuhagan(劉河間)'s theory, and other classics. Also, his clinical experience was helpful to theorize his thought. Thus, he improved medical theory by combining previous medical theory and his own experience. The essence of his thought is the importance of pathogenic Gi[邪氣] as the cause of disease and is Sambeop(三法) of Hantoha(汗吐下) as the methodology for removing pathogenic Gi[邪氣] away. He regarded pathogenic Gi as the cause of disease, and eliminated pathogenic Gi for the remedy. Namely, Sambeop(三法) of Hantoha(汗吐下) was selected as the best efficient method for driving pathogenic Gi away. Sambeop of Jangjahwa(張子和) have different meaning from previous one. Traditionally, Diaphoretic Therapy[汗法] was regarded as therapy for exogenous disease[外感病], and its effect was regarded as Balhanhaepyo(發汗解表). Emetic therapy[吐法] was throwing up Dameumsuksik(痰飮宿食) of stomach and above diaphragm. Purgation therapy[下法] means Tongbyeon(通便), Hajeok(下積), Sasil(瀉實), Chuksu(逐水) were regarded as therapy for Yangmyeongsiljeung(陽明實證) of Sanghan(傷寒). He submitted a new extensive concept of Sambeop adding traditional one, and expanded the application range of Sambeop. All methods, can cause circulation of Gihyeol(氣血) by opening the 'Hyeonbu(玄府)', like Moxibution therapy[灸薰], Steaming[蒸], Washing[洗],Heat therapy[慰], Cauterization[烙], Acupuncture therapy[鍼刺], Stone needling, Physical and breathing exercise[導引], Massage[按摩] were regarded as Diaphoretic Therapy[汗法]. Especially, he thought that Diaphoretic Therapy and venesection[瀉血] have same medical implication. If we examine the process of pushing out pathogenic Gi[邪氣] by means of Sambeop(三法), we can find the intermediation, that is circulation of Gihyeol(氣血). Its meaning is implied in the word of 'opening Hyeonbu(玄府)'. He thought that the circulation of Gihyeol(氣血) is the key to control health. Gihyeol(氣血) was circulated well under the physiological balance, but it was not circulated well under the invasion of pathogenic Gi[邪氣]. In other words, pathogenic Gi is the immediate cause of bad circulation of Gihyeol(氣血) and disease. Naturally, the doctor must remove pathogenic Gi that cause bad circulation for healing by means of Sambeop(三法). In my opinion, because the ultimate goal of Jangjahwa(張子和) was circulation of Gihyeol(氣血) by removing pathogenic Gi[邪氣], the concept of Sarnbeop(三法) could be expanded.

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Technical Trend on the Recycling Technologies for Stripping Process Waste Solution by the Patent and Paper Analysis (특허(特許)와 논문(論文)으로 본 스트리핑 공정폐액(工程廢液) 재활용(再活用) 기술(技術) 동향(動向))

  • Lee, Ho-Kyung;Lee, In-Gyoo;Park, Myung-Jun;Koo, Kee-Kahb;Cho, Young-Ju;Cho, Bong-Gyoo
    • Resources Recycling
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    • v.22 no.4
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    • pp.81-90
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    • 2013
  • Since the 1990s, the rapid development of information and communication industry, the demand for semiconductor and LCD continues to increase. Therefore in the formation of fine circuit patterns, which are the cores of sensitizer and the most expensive thinner and stripper liquor used to remove photoresist and its dilution, the amount in demand are dramatically increasing, emerging need for recycling of waste thinner and stripper liquor. Recently, recycling technologies of stripping process waste solution has been widely studied by economic aspects and environmental aspects, in terms of efficiency of the stripping process. In this study, analyzed paper and patent for recycling technologies of waste solution from stripping process. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), Korea (KR) and SCI journals from 1981 to 2010. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies.

Occupational Therapy for Activity and Participation of Children and Adolescents With Developmental Disability: A Systematic Review (국내 발달장애 아동·청소년의 작업치료 목표에 대한 체계적 고찰: ICF-CY 모델의 활동과 참여를 중심으로)

  • Park, Jihoon;Choi, Jeong-sil;Hong, Eunkyoung
    • The Journal of Korean Academy of Sensory Integration
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    • v.17 no.2
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    • pp.56-68
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    • 2019
  • Objective : The purpose of this study is to provide evidence for a systematic analysis of occupational therapy interventions for the activity and participation of children and adolescents with developmental disabilities. Methods : The articles used in this study were collected from the RISS, KISS, and DBpia databases. The key words used were "children and occupational therapy" "children and sensory integration," "adolescent and occupational therapy," "adolescent and sensory integration," "developmental disorder and occupational therapy," and "developmental disorder and sensory integration." The research period was limited to January 2008 to August 2018. Seven articles in total were selected for systematic analysis. Results : Most of the included works were single-case studies, and most subjects dealt with the autism spectrum disorder. The majority of the interventions used involved sensory integration. Occupational therapy interventions were self-care (33%), major life area (33%), learning and application (11%), communication (11%), and mobility (11%). Conclusion : This study will help with understanding the current state of occupational therapy interventions for the activity and participation. On the basis of this understanding, various studies on this subject are expected to be conducted in the future.

Relationship Identification of Diffusion Effect on High-speed Rail Demand Increase (확산효과를 통한 고속철도의 여객수요 증가현상에 관한 연구)

  • Kim, Junghwa;Ryu, Ingon;Choi, Keechoo;Lee, Myunghwan
    • Journal of the Korean Society for Railway
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    • v.19 no.4
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    • pp.539-546
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    • 2016
  • It is over 12 years since the launch of Korea Train eXpress (KTX) services. Demand for the KTX has been on the increase continuously but few studies have been produced related to this phenomenon. KTX passenger demand has been constantly increasing due to influencing factors such as the expansion of network, rise of oil prices, etc. In this study, our main focus is to verify that there are other types of elements that are causing an increase in KTX demand; our approach looks at changes in social and psychological aspect that have occurred due to the reduction of travel time and cost, as well as the imposition of a five-day workweek. In other words, we considered diffusion theory in the marketing area, which affects product selection and purchasing attitudes, as a key factor that is causing passenger demand to increase. That is to say that it is hypothesized that the demand for travel on the KTX has increased due to the train's utility, which is spread by the diffusion effect Therefore, the Bass diffusion model was applied to explain the dramatic increase in KTX passenger demand. Based on this foundation, it was also discussed how certain marketing strategies that incorporate the diffusion effect should be considered variously for sustainable management of rail transportation, while considering a steady passenger demand.

Text-Mining Analysis on the Interaction between the American Consumers Aged over 60 and Companion Pets Robots: Focused on Amazon Reviews for Joy For All Companion Pets (텍스트 마이닝을 활용한 미국 노년 소비자와 애완용 로봇 간 상호작용에 대한 분석: Joy For All Companion Pets에 대한 아마존 리뷰를 중심으로)

  • Chung, Yea-Eun;Lee, Yu Lim;Chung, Jae-Eun
    • Journal of Digital Convergence
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    • v.19 no.10
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    • pp.469-489
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    • 2021
  • This study explores consumers' responses to socially assistive robotics by using text-mining method focusing on Companion Pets from Hasbro as it gives emotional support. We conducted text frequency analysis, LDA analysis using R programming. The key findings are 1)the most frequently used words the mimicry of living pets and the appearance of companion pets, 2)the five topics were derived from the LDA analysis and classified keywords in each topic split between positive and negative, 3)user, product, environment affect the interaction between consumer and companion pets, 4)consumers who have difficulty in cognition and physical conditions use companion pets to replace living pets. This study provides an understanding of consumer responses in companion pets and gives practical implications that may improve the efficacy of usage for consumers and understand the companion robot, which provides emotional support in COVID-19.

Leased Line Traffic Prediction Using a Recurrent Deep Neural Network Model (순환 심층 신경망 모델을 이용한 전용회선 트래픽 예측)

  • Lee, In-Gyu;Song, Mi-Hwa
    • KIPS Transactions on Software and Data Engineering
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    • v.10 no.10
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    • pp.391-398
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    • 2021
  • Since the leased line is a structure that exclusively uses two connected areas for data transmission, a stable quality level and security are ensured, and despite the rapid increase in the number of switched lines, it is a line method that is continuously used a lot in companies. However, because the cost is relatively high, one of the important roles of the network operator in the enterprise is to maintain the optimal state by properly arranging and utilizing the resources of the network leased line. In other words, in order to properly support business service requirements, it is essential to properly manage bandwidth resources of leased lines from the viewpoint of data transmission, and properly predicting and managing leased line usage becomes a key factor. Therefore, in this study, various prediction models were applied and performance was evaluated based on the actual usage rate data of leased lines used in corporate networks. In general, the performance of each prediction was measured and compared by applying the smoothing model and ARIMA model, which are widely used as statistical methods, and the representative models of deep learning based on artificial neural networks, which are being studied a lot these days. In addition, based on the experimental results, we proposed the items to be considered in order for each model to achieve good performance for prediction from the viewpoint of effective operation of leased line resources.

A Study of the Definition and Components of Data Literacy for K-12 AI Education (초·중등 AI 교육을 위한 데이터 리터러시 정의 및 구성 요소 연구)

  • Kim, Seulki;Kim, Taeyoung
    • Journal of The Korean Association of Information Education
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    • v.25 no.5
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    • pp.691-704
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    • 2021
  • The development of AI technology has brought about a big change in our lives. The importance of AI and data education is also growing as AI's influence from life to society to the economy grows. In response, the OECD Education Research Report and various domestic information and curriculum studies deal with data literacy and present it as an essential competency. However, the definition of data literacy and the content and scope of the components vary among researchers. Thus, we analyze the semantic similarity of words through Word2Vec deep learning natural language processing methods along with the definitions of key data literacy studies and analysis of word frequency utilized in components, to present objective and comprehensive definition and components. It was revised and supplemented by expert review, and we defined data literacy as the 'basic ability of knowledge construction and communication to collect, analyze, and use data and process it as information for problem solving'. Furthermore we propose the components of each category of knowledge, skills, values and attitudes. We hope that the definition and components of data literacy derived from this study will serve as a good foundation for the systematization and education research of AI education related to students' future competency.

Analysis and Prediction of Trends for Future Education Reform Centering on the Keyword Extraction from the Research for the Last Two Decades (미래교육 혁신을 위한 트렌드 분석과 예측: 20년간의 문헌 연구 데이터를 기반으로 한 키워드 추출 분석을 중심으로)

  • Jho, Hunkoog
    • Journal of Science Education
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    • v.45 no.2
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    • pp.156-171
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    • 2021
  • This study aims at investigating the characteristics of trends of future education over time though the literature review and examining the accuracy of the framework for forecasting future education proposed by the previous studies by comparing the outcomes between the literature review and media articles. Thus, this study collects the articles dealing with future education searched from the Web of Science and categorized them into four periods during the new millennium. The new articles from media were selected to find out the present of education so that we can figure out the appropriateness of the proposed framework to predict the future of education. Research findings reveal that gradual tendencies of topics could not be found except teacher education and they are diverse from characteristics of agents (students and teachers) to the curriculum and pedagogical strategies. On the other hand, the results of analysis on the media articles focuses more on the projects launched by the government and the immediate responses to the COVID-19, as well as educational technologies related to big data and artificial intelligence. It is surprising that only a few key words are occupied in the latest articles from the literature review and many of them have not been discussed before. This indicates that the predictive framework is not effective to establish the long-term plan for education due to the uncertainty of educational environment, and thus this study will give some implications for developing the model to forecast the future of education.

Deng Xi Revisited: Search for the Origin of Hui Shi's Philosophy (등석(鄧析)의 재발견: 혜시(惠施) 철학의 연원을 찾아서)

  • Kim, Chul-shin
    • Journal of Korean Philosophical Society
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    • no.92
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    • pp.5-28
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    • 2011
  • This thesis was planned to correct the traditional undervaluation that although the Hui Shi philosophy aimed at "the whole of heaven and earth", it is a philosophy not to reach it to the end. For this, the origin of Hui Shi philosophy and the unique method of only Hui Shi reaching "the whole of heaven and earth" should be clearly examined, and it was seen that the key of this depends on Deng Xi. Therefore, this thesis has first examined various points of view that were confused until now in terms of the origin of Hui Shi philosophy, and pointed out its limit. Next, this thesis has paid attention to the new alternative called Deng Xi. The search on Deng Xi was carried out by thoroughly discussing meanings being implicated in "Wuhou" and "Zhuanci", which are two book's names of "Deng Xi Zi", in the context of the history of ancient Chinese philosophy. As a result, it was confirmed that the "Wuhou" of Deng Xi symbolizes that God and heaven, which were an absolute criterion from ancient times to the spring and autumn period, have fallen to existence of ineffectiveness uncapable of intervening human affairs any more. In addition, "Zhuanci" viewed that problems generated among human beings are a reflection of consciousness that will solve through clear speaking or thinking or words instead of Heaven's will. In conclusion, this thesis has tried the origin of Hui Shi philosophy and an explanation of a unique method of only Hui Shi reaching 'the whole of heaven and earth' from the idea of Deng Xi like this.