• Title/Summary/Keyword: trend studies

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Rainfall Trend Detection Using Non Parametric Test in the Yom River Basin, Thailand

  • Mama, Ruetaitip;Bidorn, Butsawan;Namsai, Matharit;Jung, Kwansue
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.424-424
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    • 2017
  • Several studies of the world have analyzed the regional rainfall trends in large data sets. However, it reported that the long-term behavior of rainfall was different on spatial and temporal scales. The objective of this study is to determine the local trends of rainfall indices in the Yom River Basin, Thailand. The rainfall indices consist of the annual total precipitation (PRCTPOP), number of heavy rainfall days ($R_{10}$), number of very heavy rainfall days ($R_{20}$), consecutive of dry days (CDD), consecutive of wet days (CWD), daily maximum rainfall ($R_{x1}$), five-days maximum rainfall ($R_{x5}$), and total of annual rainy day ($R_{annual}$). The rainfall data from twelve hydrological stations during the period 1965-2015 were used to analysis rainfall trend. The Mann-Kendall test, which is non-parametric test was adopted to detect trend at 95 percent confident level. The results of these data were found that there is only one station an increasing significantly trend in PRCTPOP index. CWD, which the index is expresses longest annual wet days, was exhibited significant negative trend in three locations. Meanwhile, the significant positive trend of CDD that represents longest annual dry spell was exhibited four locations. Three out of thirteen stations had significant decreasing trend in $R_{annual}$ index. In contrast, there is a station statistically significant increasing trend. The analysis of $R_{x1}$ was showed a station significant decreasing trend at located in the middle of basin, while the $R_{x5}$ of the most locations an insignificant decreasing trend. The heavy rainfall index indicated significant decreasing trend in two rainfall stations, whereas was not notice the increase or decrease trends in very heavy rainfall index. The results of this study suggest that the trend signal in the Yom River Basin in the half twentieth century showed the decreasing tendency in both of intensity and frequency of rainfall.

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Comparison of Trend Tests for Genetic Association with Sibship Data (형제 자료에 근거한 유전연관성 추세 검정법의 비교)

  • Oh, Young-Sin;Kim, Han-Sang;Son, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.23 no.5
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    • pp.845-855
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    • 2010
  • Extensively used case-control designs in medical studies can also be powerful and efficient for family association studies as long as an analysis method is developed for the evaluation of association between candidate genes and disease. Traditional Cochran-Armitage trend test is devised for independent subjects data, and to apply this trend test to the biologically related siblings one has to take into account the covariance among related family members in order to maintain the correct type I error rate. We propose a more powerful trend test by introducing weights that reflect the number of affected siblings in families for the evaluation of the association of genetic markers related to the disease. An application of our method to a sample family data, in addition to a small-scale simulation, is presented to compare the weighted and unweighted trend tests.

Forest Fragmentation and its impacts : A review (산림파편화에 대한 국내·외 연구동향)

  • Kim, Eunyoung;Song, Wonkyong;Lee, Dong-Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.2
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    • pp.149-162
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    • 2012
  • Habitat loss and fragmentation are ongoing major anthropogenic impacts on landscapes, which can strongly affect ecosystems, populations and species. The studies on forest fragmentation have been progressed, but the studies on definition of forest fragmentation and their synthetic trend in South Korea still leaves much to be desired. Therefore we set the definition of forest fragmentation and reviewed the related papers. We can give a definition that forest fragmentation is not only a process of spatial landscape transformation, but also a process of ecosystem change by it. The trend of studies on forest fragmentation divided into two fields, landscape and ecosystem changes. Forest fragmentation caused by land change altered the composition and configuration of forest patches. Most studies related on that analyzed the change using landscape index. The effects of forest fragmentation on ecosystem subdivided into three fields : biodiversity, edge effects, and invasive species, but the studies in South Korea is short. The study on relations between forest fragmentation and ecosystem change is necessary to face the Convention on Biological Diversity in South Korea. In addition, the fundamental studies on biodiversity is important to mitigate against forest fragmentation.

A Study on the Hair style in Respect of Fashion Trend in 1960's (1960년대 패션트렌드에 따른 헤어스타일의 양상)

  • Yoo, Mee-Geum;Choi, Jung-Soon
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.2 s.2
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    • pp.1-11
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    • 2004
  • The purpose of this study was to analyze the hair style trend in the respect of fashion trend in 1960s. The study also attempted if there were significant influences to current hair designers and hair styles as beehive, mods hair, short cut. geometric cut, wigs, natural hair, unisex hair. This study is a descriptive study, involving the collection of picture data and examine the art of the 1960's. Because 1960's is a revolutionary decade in the way of living and fashion trend. This study also adopted review of literature and analysis of magazines. 1960's was a period of major street fashion as Mods, Jackie Look, Miniskirt, Pop Art, Op Art Look, Space Look, Hippie Look, Unisex Look. The results of this study can be summarized as follows: 1) A review of literature had shown that little or no studies for an in depth analysis of 1960's fashion trend and hair design. 2) During the sixties, the trend of fashion and hair style were remarkable change in the way of living. 3) There were strong influences hair styles of 1960's until today.

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A study on the analysis of bus public Wi-Fi security access trends (버스 공공와이파이 보안 접속 동향 분석에 관한 연구)

  • Choi, Hong-Ju
    • Design & Manufacturing
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    • v.15 no.4
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    • pp.14-23
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    • 2021
  • In this study, we have analyzed the access status and the data usage trend of the public Wi-Fi on the bus, which has not been carried out in the previous studies. The analysis period of this study is 5 months from Nov. 2020 to Mar. 2021. When we compared the access status of Seoul metropolitan and the non-metropolitan region against each region's deployment status ratio, the access ratio of the metropolitan region was higher than the non-metropolitan region, of which the gap was 4.53%. The access for each region showed the growing trend, which was 43.5% on average. The data usage also showed the growing trend, 2.7% on average. Weekly data usage showed the growing trend irrespective of weekdays or weekends. The data usage of the weekdays was 695GB higher than weekends. The data usage during commuting hours including school (7:00~9:00 a.m. and 4:00~6:00 p.m.) was higher than 3,000GB. We can conclude that bus public Wi-Fi was used more actively in non-metropolitan region than Seoul metropolitan region by the office workers and students. The secure access also showed the growing trend. And the secure data usage also showed the growing trend.

A Study on the Trend of the School Violence in Elementary schools (초등학생의 학교폭력 실태와 경향에 대한 연구)

  • Kim, Sun-Ae
    • Korean Journal of Human Ecology
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    • v.12 no.3
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    • pp.321-336
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    • 2003
  • This study aims at more exactly identifying current status and trend of the school violence in elementary schools. Many previous studies have addressed the issue with their own views and methodologies, and mostly ended up as one-time works without subsequent observation over years. From such respective studies, we could hardly figure out an integral and precise shape on the school violence in terms of fact and tendency. To my knowledge, this is the first time-lag design on the school violence which is conducted nation wide, where the same concepts and measures were applied to the population. The research conclusions are follows: (1) both offenders and victims of the school violence tend to increase, (2) compared 10 girls, boys have more experience of the school violence, and (3) both offenders and victims could be recruited from the same group.

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Culture, Memory, and Literature: In Search of an Interdisciplinary Relationship Between Cultural and Literary Studies (문화, 회상 그리고 문학: 문화학과 문예학의 학제적 연관성에 관한 모색″)

  • 최문규
    • Lingua Humanitatis
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    • v.1 no.2
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    • pp.67-90
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    • 2001
  • In the past few years, a trend has emerged emphasizing the interdisciplinary relationship between cultural and literary studies, and "memory" has been suggested as the central theme in this trend. According to Aleida and Jan Assmann, "memory" as collective memory (not individual recollection) has various functions and forms, of which communicative memory and cultural memory occupy opposite poles of a central axis. Whereas communicative memory relates to the living past shared among contemporaries, cultural memory relates to "recollected history" rather than factual history. Cultural memory finds transmission through symbolic media such as myths, festivities, and literary works. Literary works preserve critical and living memories as opposed to forgotten memories. In other words, literature should be better read as "criticism and memory" than "imitation and preservation." Works of literature are characterized by a turning away from repetition toward representation-the process of "making present" of what is past.

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Artificial Intelligence and Air Pollution : A Bibliometric Analysis from 2012 to 2022

  • Yong Sauk Hau
    • International journal of advanced smart convergence
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    • v.13 no.1
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    • pp.48-56
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    • 2024
  • The application of artificial intelligence (AI) is becoming increasingly important to coping with air pollution. AI is effective in coping with it in various ways including air pollution forecasting, monitoring, and control, which is attracting a lot of attention. This attention has created high need for analyzing studies on AI and air pollution. To contribute for satisfying it, this study performed bibliometric analyses on the studies on AI and air pollution from 2012 to 2022 using the Web of Science database. This study analyzed them in various aspects such as the trend in the number of articles, the trend in the number of citations, the top 10 countries of origin, the top 10 research organizations, the top 10 research funding agencies, the top 10 journals, the top 10 articles in terms of total citations, and the distribution by languages. This study not only reports the bibliometric analysis results but also reveals the eight distinct features in the research steam in studies on AI and air pollution, identified from the bibliometric analysis results. They are expected to make a useful contribution for understanding the research stream in AI and air pollution.

A Review of Clinical Studies for Journal of Oriental Neuropsychiatry - since 2001 to 2010 - (동의신경정신과학회지에 게재된 임상연구논문 동향분석 - 2001년부터 2010년까지 -)

  • Heo, Eun-Jung;Jeon, Won-Kyung;Kim, Wu-Young;Han, Chang-Hyun
    • Journal of Oriental Neuropsychiatry
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    • v.22 no.3
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    • pp.115-125
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    • 2011
  • Objectives : This study was aimed to review the trend of clinical studies in Journal of Oriental Neuropsychiatry since 2001 to 2010. Methods : We collected 260 clinical studies and analyzed them for publish year, sorts of disease or symptoms, pattern identification diagnosis, and classification of clinical studies. Among them, we selected 46 clinical experimental studies and these studies were further analyzed for publish year, research institution, sort of disease or symptoms, sorts of treatments, number of subject, and pattern identification diagnosis. Results : The number of clinical studies in Journal of Oriental Neuropsychiatry have increased since the year of 2001. There were 62 kinds of diseases and symptoms and Hwa-Byung had the highest number of studies followed by depression, headache, insomnia and so on. The clinical experimental studies, which took up 17% of the clinical studies, have increased since 2001 and was varied with year. There were 13 reserch institutions for clinical experimental studies and they studied about stress, dementia, Hwa-Byung, and so on. Most of studies researched treatment about acupuncture, herb medicine, and meditation treatment for persons under 144. There are only 22% of studies using pattern identification diagnosis. Conclusions : For the development of oriental medicine for psychiatric disease, we need more qualifying clinical studies like RCT. We hope more researchers for psychiatry disease of oriental medicine will be interested in the publication of clinical studies and this will serve to produce advance of oriental medicine as evidence based medecine.

Trends of Upper Jet Streams Characteristics (Intensity, Altitude, Latitude and Longitude) Over the Asia-North Pacific Region Based on Four Reanalysis Datasets (재분석자료들을 활용한 아시아-북태평양 상층제트의 강도(풍속) 및 3차원적 위치 변화 경향)

  • So, Eun-Mi;Suh, Myoung-Seok
    • Atmosphere
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    • v.27 no.1
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    • pp.1-16
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    • 2017
  • In this study, trends of upper jet stream characteristics (intensity, altitude, latitude, and longitude) over the Asia-North Pacific region during the recent 30 (1979~2008) years were analyzed by using four reanalysis datasets (CFSR, ERA-Int., JRA-55, MERRA). We defined the characteristics of upper jet stream as the averages of mass weighted wind speed, mass-flux weighted altitude, latitude and longitude between 400 and 100 hPa. Due to the vertical averaging of jet stream characteristics, our results reveal a weaker spatial variabilities and trends than previous studies. In general, the four reanalysis datasets show similar jet stream properties (intensity, altitude, latitude and longitude) although the magnitude and trends are slightly different among the reanalysis datasets. The altitude of MERRA is slightly higher than that of others for all seasons. The domain averaged intensity shows a weakening trend except for winter and the altitude of jet stream shows an increasing trend for all seasons. Also, the meridional trend of jet core shows a poleward trend for all seasons but it shows a contrasting trend, poleward trend in the continental area but equatorward trend in the Western Pacific region during summer. The zonal trend of jet core is very weak but a relatively strong westward trend in jet core except for spring and winter. The trends of jet stream characteristics found in this study are thermodynamically consistent with the global warming trends observed in the Asia-Pacific region.