• 제목/요약/키워드: S-N approach

검색결과 845건 처리시간 0.031초

재해기상 언론기사 빅데이터를 활용한 피해정보 자동 분류기 개발 (Developing and Evaluating Damage Information Classifier of High Impact Weather by Using News Big Data)

  • 조수지;이기광
    • 산업경영시스템학회지
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    • 제46권3호
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    • pp.7-14
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    • 2023
  • Recently, the importance of impact-based forecasting has increased along with the socio-economic impact of severe weather have emerged. As news articles contain unconstructed information closely related to the people's life, this study developed and evaluated a binary classification algorithm about snowfall damage information by using media articles text mining. We collected news articles during 2009 to 2021 which containing 'heavy snow' in its body context and labelled whether each article correspond to specific damage fields such as car accident. To develop a classifier, we proposed a probability-based classifier based on the ratio of the two conditional probabilities, which is defined as I/O Ratio in this study. During the construction process, we also adopted the n-gram approach to consider contextual meaning of each keyword. The accuracy of the classifier was 75%, supporting the possibility of application of news big data to the impact-based forecasting. We expect the performance of the classifier will be improve in the further research as the various training data is accumulated. The result of this study can be readily expanded by applying the same methodology to other disasters in the future. Furthermore, the result of this study can reduce social and economic damage of high impact weather by supporting the establishment of an integrated meteorological decision support system.

Study on multi-stage magnetic separation device for paramagnetic materials operated in low magnetic fields

  • F. Mishima;Aoi Nagahama;N. Nomura;S. Nishijima
    • 한국초전도ㆍ저온공학회논문지
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    • 제25권3호
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    • pp.13-17
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    • 2023
  • Magnetic separation technology for small paramagnetic particles has been desired for the volume reduction of contaminated soil from the Fukushima nuclear power plant accident and for the separation of scale and crud from nuclear power plants. However, the magnetic separation for paramagnetic particles requires a superconducting high gradient magnetic separation system applied, hence expanding the bore diameter of the magnets is necessary for mass processing and the initial and running costs would be enormous. The use of high magnetic fields makes safe onsite operation difficult, and there is an industrial need to increase the magnetic separation efficiency for paramagnetic particles in as low a magnetic field as possible. Therefore, we have been developing a magnetic separation system combined with a selection tube, which can separate small paramagnetic particles in a low magnetic field. In the previous technique we developed, a certain range of particle size was classified, and the classified particles were captured by magnetic separation. In this new approach, the fluid control method has been improved in order to the selectively classify particles of various diameters by using a multi-stage selection tube. The soil classification using a multi-stage selection tube was studied by calculation and experiment, and good results were obtained. In this paper, we report the effectiveness of the multi-stage selection tube was examined.

국내 화강암질암내 심부지하수의 지구화학적 특성 (Geochemical Characteristics of Deep Granitic Groundwater in Korea)

  • 이종운;전효택;전용원
    • 대한지하수환경학회지
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    • 제4권4호
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    • pp.199-211
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    • 1997
  • 방사성폐기물의 지하심부 처분을 위한 수리지구화학적 기초자료를 얻기 위하여 국내 화강암질암을 대수층으로 하는 지표수 및 지하수를 대상으로 시료채취와 문헌조사를 통하여 dataset을 구축하였다. 심도에 따른 용존물질의 절대 및 상대함량과 거동특성을 통계적으로 파악하고 지하수의 화학적 조성의 원인이 되는 물-암석반응을 열역학적 해석과 결부하여 규명하였다. 화강암질암 대수층에서 총용존물질량은 심도에 따라 통계적으로 유의하게 증가함으로써 심부로 갈수록 물-암석반응을 많이 거친 물이 존재함을 나타낸다. 지하수의 조성은 초기의 $Ca^{2+}$-(C $l^{-}$+S $O_4$$^{2-}$ ) 또는 $Ca^{2+}$-HC $O_3$$^{-}$ 유형에서 시작하여 점차 $Ca^{2+}$-HC $O_3$$^{-}$ 유형을 거친 후 최종적으로 $Na^{+}$-HC $O_3$$^{-}$ 또는 $Na^{+}$-(C $l^{-}$+S $O_4$$^{2-}$ ) 유형으로 진화하는 경향을 보인다. 이러한 특징은 $Ca^{2+}$, $Na^{+}$ , $SiO_2$(aq)가 대표하는 다음의 세 가지 기제에 의하여 설명이 가능하다. 1) 천부지하수의 화학조성을 조절하는 가장 주된 반응은 방해석의 용해이나 중간지하수를 거치면서 방해석 포화상태에 이르러 광물상으로 침전되며 심부지하수에서는 $Ca^{2+}$의 함량이 감소한다. 2) 심부지하수에서는 사장석의 용해가 주도적인 반응으로 작용하며 $Na^{+}$를 공급하므로써 함량을 증가시킨다. 3) 중간 및 심부지하수에서는 kaolinite-smectite 또는/그리고 kaolinite-illite 간의 반응이 평형에 도달함으로써 용존 $SiO_2$(aq) 함량을 유지시키며 또한 이들 반응은 심부지하수에서 $Mg^{2+}$$K^{+}$가 결핍되는 현상의 중요한 원인이 된다.

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『본초정화(本草精華)』의 해제(解題)에 관한 역사학적(醫史學的) 접근 (『Bonchojeonghwa(本草精華)』, Medical Historical Approach to Bibliographic Notes)

  • 김홍균
    • 한국의사학회지
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    • 제24권2호
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    • pp.25-55
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    • 2011
  • The currently existing "Bonchojeonghwa (本草精華)" is a manuscript without the preface and the epilogue, composed of 2 books in 2 volumes. This book is a quintessence of knowledge on science of medicinal ingredients (medicinal phytology I herbal science) as well as an trial of new development in Chosun medical science. I.e. this book includes surprising change representing medical science in Chosun dynasty as a single publication on science of medicinal ingredients. It holds a value essential to clinician as a specialized book in medicinal ingredients, and Includes richer content on medicinal ingredients than any other books published before. In addition, it is away from boring list-up of superfluous knowledge as seen in "Bonchokangmok(本草綱目)" published in China, and well summarizes essential knowledge which can be used within a range of medicines available in Korea. This book has an outstanding structure that can be even used in today's textbook on science of medicinal ingredients, as it has clear theory, system and classification. Because it handles essential learning points prior to prescription to disease, it is possible to configure new prescription and adjustment of medicinal materials. Moreover, this book can play a good role for linguistic study at the time of publication, because it describes many drugs in Hangul in many parts of the book. "Bonchojeonghwa" includes a variety of animals, plants and mineral resources in Korea, like "Bonchokangmok" which was recently listed in UNESCO. As such, it has a significance in natural history as well as pharmacy in Korean Medicine. It has various academic relationships all in biologic & abiologic aspects. It has importance in sharing future biological resources, building up international potential, setting up the standard for biologic species under IMF system, and becoming a base for resource diplomacy. We should not only see it as a book on medicinal ingredients in terms of Oriental Medicine, but also make an prudent approach to it in terms of study strengthening Korea's national competitiveness. After bibliographical reviewing on the features & characteristics of the only existing copy of "Bonchojeonghwa" housed in Kyujanggak(奎章閣) of Seoul National University, the followings are noted. First, "Bonchojeonghwa" is a specialized book on medicinal ingredients voluntarily made by private hands to distribute knowledge on drugs in the desolate situation after Imjinoeran (Japanese Invasion in 1592), without waiting for governmental help. Second, it raised accessibility and practicality by new editing. Third, it classified 990 different kinds of drugs into plant, animal, and mineral at large, and dassified more in detail into 15 'Bu' and 48 'Ryu' at 258 pages. Fourth, the publication of this book is estimated to be around 1625~1633, at the time of Injo's reign in 17th century. Fifth, it contains the existing & up-to-date knowledge at the time of publication, and it is possible to see the supply-demand situation by Hangul descriptions in 149 places in the book. By the fact that there are many linguistic evidences of 17th century, explains well when the book was published.

습지 토양 내 체외효소 활성도를 조절하는 인자에 대한 고찰 (A review of factors that regulate extracellular enzyme activity in wetland soils)

  • 김하련
    • 미생물학회지
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    • 제51권2호
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    • pp.97-107
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    • 2015
  • 육상과 수계의 전이지대에 위치한 습지는 빈번한 침수, 육상생태계로부터의 영양염류의 유입, 수계와 토양에 적절하게 적응된 식생의 존재 및 토양 내 산소 결핍과 같은 독특한 특징을 가지고 있다. 이러한 생지화학적 특성과 독특한 식생의 존재는 유기물의 분해과정에 물리적 화학적 영향을 미치고 있는데, 특히 미생물에서 생산되는 체외효소 활성도는 유기물의 분해 과정과 관련을 맺고 있다. 체외효소는 고분자 유기물을 간단한 형태의 유기탄소, 무기 질소, 인, 황으로 분해하여 미생물과 식물이 용이하게 이들 영양물질을 흡수할 수 있도록 도움을 주기 때문에, 체외효소에 대한 연구는 습지 토양 내에서의 유기물 분해와 물질순환의 기작을 이해하는 데 필수적인 요소이다. 본 연구는 습지 토양 내 ${\beta}$-glucosidase, ${\beta}$-N-acetylglucosaminidase, phosphatase, arylsulfatase, phenol oxidase와 같은 체외 효소활성도에 영향을 미치는 물리적 생지화학적 요소가 무엇인지 문헌연구를 통하여 고찰하였다. 물리적 요소로써, pH와 유기물의 입자 크기는 체외효소 활성도에 크게 영향을 미치지 않았으나, 온도에 대한 영향은 미생물의 극한 온도에서의 적응성 정도에 따라 다양하게 나타났다. 화학적 요소로써, 탄소, 질소, 인의 첨가는 습지 토양의 영양상태, C:N 비율과 제한 요소, 및 체외효소의 종류에 따라 그 영향이 다양하게 발현되었다. 특히, 유기물의 기질 특성(Substrate quality)은 다른 어떤 요소보다도 체외효소 활성도에 큰 영향을 미치는 것으로 나타났다. 향후 연구 과제로써는 기후 변화와 질소 침적의 증가에 따른 효소 활성도의 변화 및 분자생물학적 접근을 통한 미생물 군집과 체외효소 기능간의 관계를 규명하는 연구가 필요하다. 또한, 습지 토양내 체외효소 활성도를 극대화 할 수 있는 환경을 조성함으로써, 앞으로 습지 토양이 오염물질을 제거하고 습지의 생태학적 기능을 최대화 할 수 있는 연구가 요구된다.

사용 상황에 맞게 분류된 사물의 데이터 시각화와 제어를 위한 인터페이스 개발 (Development of an Interface for Data Visualization and Controlling of Classified Objects based on User Conditions)

  • 박희성;한민석;최유리
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제22권7호
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    • pp.320-325
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    • 2016
  • IoT(Internet of Things) 기술의 급격한 발전으로 스마트 홈 환경에서 사용되는 사물들의 수가 급격하게 증가하고 있다. Mobile 환경에서 다양한 스마트 사물을 효율적으로 관리 및 제어하기 위해 Application을 통해 제공한다. 하지만, 기존의 방법은 단순 정보 나열하여 보여줄 뿐 사물 간의 유의미한 정보를 나타내지 않아 스마트 사물의 탐색과 제어가 어렵다. 본 논문에서는 문제를 해결하기 위해 사용자의 사물 사용 패턴 정보에 맞춰 사물의 데이터를 효율적으로 시각화하고 제어할 수 있는 인터페이스를 제안한다. 제안된 방법은 스마트 사물 기기의 사용 상황에 맞게 시간 축으로 패턴 정보를 분류하고 사물의 데이터를 시각화 하여 그룹 및 개별 제어를 쉽게 하기 위한 인터페이스를 제공한다. 또한 과거 및 현재의 전체 사물 정보를 종합하여 유의미한 정보를 확인할 수 있다.

Small scale computational vibration of double-walled CNTs: Estimation of nonlocal shell model

  • Asghar, Sehar;Khadimallah, Mohamed Amine;Naeem, Muhammad N.;Ghamkhar, Madiha;Khedher, Khaled Mohamed;Hussain, Muzamal;Bouzgarrou, Souhail Mohamed;Ali, Zainab;Iqbal, Zafar;Mahmoud, S.R.;Algarni, Ali;Taj, Muhammad;Tounsi, Abdelouahed
    • Advances in concrete construction
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    • 제10권4호
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    • pp.345-355
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    • 2020
  • In this paper, vibration characteristics of double-walled carbon nanotubes (CNTs) is studied based upon nonlocal elastic shell theory. The significance of small scale is being perceived by developing nonlocal Love shell model. The wave propagation approach has been utilized to frame the governing equations as eigen value system. The influence of nonlocal parameter subjected to diverse end supports has been overtly analyzed. An appropriate selection of material properties and nonlocal parameter has been considered. The influence of changing mechanical parameter Poisson's ratio has been investigated in detail. The dominance of boundary conditions via nonlocal parameter is shown graphically. The results generated furnish the evidence regarding applicability of nonlocal shell model and also verified by earlier published literature.

리더십 유형이 구성원의 조직몰입과 직무만족에 미치는 영향 : 종합병원 의무기록실을 대상으로 (Leadership Style of Medical Record Directors at General Hospitals and it's Effect on the Organizational Commitment and Job Satisfaction)

  • 최수연;최재욱;이준영;최수미;유효순;신의철
    • 한국의료질향상학회지
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    • 제10권2호
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    • pp.144-153
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    • 2003
  • 1) Background: The hospitals of modem society, like any other business entities, have to constantly strive to secure their survival from aggressive changes and competition outside. In this unstable environment, effective leadership is one of the most effective strategies for securing organization's growth as well as stability. This study investigated types of leadership (transformational or transactional) that is dominant in medical record departments and compared it's effects on organizational commitment and job satisfaction of their organizational members by types. 2) Method: A questionnaire was developed and mailed to all medical record administrators working at general hospitals throughout the country except department directors (N=450). Of these, 150 useable questionnaires were returned and analyzed by t-test, multiple regression analysis using SPSS. 3) Results: The organizational commitment and job satisfaction were a little bit higher than moderate level, and that of leadership perceived by medical record administrators was also in moderate level throughout types. Significant characteristics (positively) related to organizational commitment and job satisfaction by univariate analysis were marital status (married), position (middle management) and both type of leadership. However transformational leadership was the only significant factor in leadership styles after considering all the factors related to organizational commitment and job satisfaction together by multivariate analysis. 4) Conclusion: The average organizational commitment and job satisfaction of medical record administrators was just in moderate level. Efforts should be made to increase them by improving leadership capacity of medical record directors, primarily by using transformational leadership approach.

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Cancer Perceptions Among Smokeless Tobacco Users: A Qualitative Study of US Firefighters

  • Jitnarin, Nattinee;Poston, Walker S.C.;Jahnke, Sara A.;Haddock, Christopher K.;Kelley, Hannah N.
    • Safety and Health at Work
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    • 제11권3호
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    • pp.284-290
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    • 2020
  • Background: Prevalence rates of smokeless tobacco (SLT) use among firefighters are remarkably high and substantially higher than similar occupational groups and the general U.S. population. The purpose of this study was to explore the perspectives of fire service personnel regarding cancer and its associations with tobacco and SLT use. Methods: This descriptive study used a qualitative approach. Key informant interviews were conducted in 39 career firefighters and fire service administration from across the U.S. Discussion were recorded, transcribed verbatim and transferred to NVivo software for narrative analysis. Topics explored included cancer perceptions, attitudes and beliefs, and cultural factors related to SLT use behaviors. Results: Major themes that emerged among fire service personnel included concerns about cancer and its risk factors including firefighting tasks, such as fire overhaul operations, and from their lifestyle behaviors, such as alcohol and tobacco use. Firefighters also suggested a number of reasons for their increased SLT use, such as fire department tobacco-free policy and fire service culture. Conclusion: The current study provides a rich foundation for future research, prevention, and intervention efforts for the fire service and research communities regarding tobacco and SLT use and cancer risk. Additional research on firefighters' cancer beliefs deserves future research in order to improve messaging about the risks of cancer due to firefighting.

토픽 모델과 소셜 네트워크를 이용한 개발자 추천방법 (A Developer Recommendation Technique Based on Topic Model and Social Network)

  • 양근석;장도;이병정
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제41권8호
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    • pp.557-568
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    • 2014
  • 최근 소프트웨어 규모가 더욱 커지고 복잡해지고 있다. 하루에도 수많은 버그 리포트들이 버그저장소에 전송 되어 개발자들의 업무가 늘어나고 있다. 이러한 버그 리포트들을 적절한 개발자에게 전달하여 빠르고 정확하게 소프트웨어의 결함이 수정되어야 하는데, 많은 버그 리포트들이 적절하지 않는 개발자에게 배정되어 다른 개발자에게 다시 재배정 되는 경우가 빈번하게 일어나고 있다. 이것은 배정자가 전송받은 버그 리포트들을 정확히 이해하지 못했거나, 또는 모든 개발자들의 능력을 바르게 파악하지 못해 발생한다. 이것은 소프트웨어 유지보수에 개발자의 시간과 노력을 많이 필요하게 한다. 이러한 문제를 해결하기 위해 본 연구에서는 버그 리포트와 관련된 토픽을 찾아내고, 토픽 내 개발자들의 소셜 네트워크 관계를 분석해서 적절한 개발자를 추천하는 기법을 제안한다. 그리고 공개 소스 프로젝트를 이용한 개발자 추천에 대한 성능비교 실험을 통하여 본 연구에서 제안한 방법이 효과적이라는 것을 보인다.