• 제목/요약/키워드: Trend change

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가우시안 프로세스 회귀분석을 이용한 지하수위 추세분석 및 장기예측 연구 (Groundwater Level Trend Analysis for Long-term Prediction Basedon Gaussian Process Regression)

  • 김효건;박은규;정진아;한원식;김구영
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제21권4호
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    • pp.30-41
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    • 2016
  • The amount of groundwater related data is drastically increasing domestically from various sources since 2000. To justify the more expansive continuation of the data acquisition and to derive valuable implications from the data, continued employments of sophisticated and state-of-the-arts statistical tools in the analyses and predictions are important issue. In the present study, we employed a well established machine learning technique of Gaussian Process Regression (GPR) model in the trend analyses of groundwater level for the long-term change. The major benefit of GPR model is that the model provide not only the future predictions but also the associated uncertainty. In the study, the long-term predictions of groundwater level from the stations of National Groundwater Monitoring Network located within Han River Basin were exemplified as prediction cases based on the GPR model. In addition, a few types of groundwater change patterns were delineated (i.e., increasing, decreasing, and no trend) on the basis of the statistics acquired from GPR analyses. From the study, it was found that the majority of the monitoring stations has decreasing trend while small portion shows increasing or no trend. To further analyze the causes of the trend, the corresponding precipitation data were jointly analyzed by the same method (i.e., GPR). Based on the analyses, the major cause of decreasing trend of groundwater level is attributed to reduction of precipitation rate whereas a few of the stations show weak relationship between the pattern of groundwater level changes and precipitation.

Mortality from Stomach Cancer in Serbia, Excluding the Province of Kosovo, in the 1991-2009 Period

  • Ilic, Milena;Prodovic, Tanja;Milosavljevic, Zoran;Ljujic, Biljana
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.2067-2070
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    • 2013
  • Background/Aim: Stomach cancer is the second most common cause of death from all malignant tumors in the world (third in men, fifth in women), with a strong decreasing trend in most developed countries. The aim of this descriptive epidemiological study was to analyze mortality of stomach cancer in Serbia, excluding the Province of Kosovo, in the 1991-2009 period. Materials and Methods: In data analysis, we used mortality rates which were standardized directly using those of the world population as a standard. In order to analyze the mortality trend from stomach cancer, linear trend and regression analysis were used. Confidence intervals (CIs) for the average age-adjusted and age-specific mortality rates were assessed with 95% level of probability. Mortality data were derived from the data file of the Statistical Office of the Republic of Serbia. Results: During the 1991-2009 period, a significant downward trend in mortality of stomach cancer was recorded in Serbia (y=9.78 - 0.13x, p=0.000; average annual percent change was -6.3 (95%CI, -7.8 to - 4.8). During the same period, a significant decrease in mortality trend was found both in male (y=14.13 - 0.20x; p=0.000; % change was -7.7 (95%CI, -10.9 to -4.5) and female populations (y=6.27 - 0.08x; p=0.000; % change was - 4.4 (95%CI, -5.3 to -3.6). Conclusion: Decreasing trends in mortality from stomach cancer in Serbia are similar to those in most developed countries.

Effects of CO2 and Climate on water use efficiency and their linkage with the climate change

  • Umair, Muhammad;Kim, Daeun;Choi, Minha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.149-149
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    • 2019
  • Gross Primary production (GPP) and evapotranspiration (ET) are the two critical components of carbon and water cycle respectively, linking the terrestrial surface and ecosystem with the atmosphere. The ratio between GPP to ET is called ecosystem water use efficiency (EWUE) and its quantification at the forest site helps to understand the impact of climate change due to large scale anthropogenic activities such as deforestation and irrigation. This study was conducted at the FLUXNET forest site CN-Qia (2003-2005) using Community land model (CLM 5.0). We simulated carbon and water fluxes including GPP, ecosystem respiration (ER), and ET using climatic variables as forcing dataset for 30 years (1981-2010). Model results were validated with the FLUXNET tower observations. The correlation showed better performance with values of 0.65, 0.77, and 0.63 for GPP, ER, and ET, respectively. The model underestimated the results with minimum bias of -0.04, -1.67, and -0.40 for GPP, ER, and ET, respectively. Effect of climate 'CLIM' and '$CO_2$' were analyzed based on EWUE and its trend was evaluated in the study period. The positive trend of EWUE was observed in the whole period from 1981-2010, and the trend showed further increase when simulated with rising $CO_2$. The time period were divided into two parts, from 1981-2000 and from 2001 to 2010, to identify the warming effect on EWUE. The first period showed the similar increasing trend of EWUE, but the second period showed slightly decreasing trend. This might be associated with the increase in ET in the wet temperate forest site due to increase in climate warming. Water use efficiency defined by transpiration (TR) (TWUE), and inherent-TR based WUE (IT-WUE) were also discussed. This research provides the evidence to climate warming and emphasized the importance of long term planning for management of water resources and evaporative demand in irrigation, deforestation and other anthropogenic activities.

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Mann-Kendall 비모수 검정과 Sen's slope를 이용한 최근 40년 남한지역 계절별 평균기온의 경향성 분석 (A trend analysis of seasonal average temperatures over 40 years in South Korea using Mann-Kendall test and sen's slope)

  • 진대현;장성환;김희경;이영섭
    • 응용통계연구
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    • 제34권3호
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    • pp.439-447
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    • 2021
  • 범지구적 이상기후의 잦은 출현으로 기상 변화에 대한 관련 연구가 활발히 진행되고 있지만, 장기간 축적된 기상자료를 이용한 경향성 분석 연구는 부족하였다. 본 연구에서는 비모수적 분석방법을 이용해 40년간 종관기상관측장비(ASOS)로 부터 축적된 기온 시계열 자료의 경향성을 분석하였다. 남한지역의 연평균 기온과 계절별 평균기온 시계열 자료에 대한 Mann-Kendall 검정 결과 상승 경향성이 존재하는 것으로 나타났다. 또한 Pettitt 검정을 적용해 탐색된 변동점을 전후로 경향성의 정도를 파악할 수 있는 Sen's slope를 계산한 결과, 변동점 이후의 최근 자료에서 기온의 상승 경향성이 더욱 큰 것을 확인하였다.

Assessing the variability of climate indices and the role of climate variables in Chungcheong provinces of South Korea

  • Adelodun, Bashir;Cho, Hyungon;Odey, Golden;Adeola, Khalid Adeyemi;Choi, Kyung Sook
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2022년도 학술발표회
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    • pp.154-154
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    • 2022
  • The frequency of natural disasters, including floods and drought events, driven by climate change has increased in recent times. Investigating the climate regimes and the roles of climate variables are indispensable to forestall future climate change-related disasters. This study compares the variability of two popular and widely used climate indices i.e., the United Nations Environment Programme (UNEP) aridity index and the Modified De-Martonne (MDM) index to assess the trend of climate change in the Chungcheong provinces of South Korea. The trend of annual and monthly climate indices was conducted using a non-parametric Mann-Kendall test and Kolmogorov-Smirnov normality test with daily climate data of 48 years (1978-2020) from 10 synoptic stations. The findings indicate that UNEP and MDM indices had a wet climate regime for the annual trend, with the UNEP index indicating a relatively humid trend of 60% humid, 20% semi-arid, and 10% sub-humid for the 48-years study period. However, the MDM index showed a high frequency of a severe wet climatic condition followed by the semi-arid condition. The months of July and August had the highest occurring frequency of the wet climatic condition (90%) for both UNEP and MDM indices. Comparing the two provinces, Chungnam showed a relatively wetter climatic condition using the UNEP index, while the MDM index indicated no significant regional difference in climate regime between the two provinces. The Kolmogorov-Smirnov normality test showed that all the 10 stations are normally distributed for monthly climate conditions at a 5% significant level in the two provinces except five stations for UNEP index and four stations for MDM index in the month of January.

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터널 3차원 내공변위의 해석을 통한 막장전방 지반상태변화 예측 (Prediction of Change in Ground Condition Ahead of Tunnel Face Using Three-dimensional Convergence Analysis)

  • 김기선;김영섭;유광호;박연준;이대혁
    • 터널과지하공간
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    • 제13권6호
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    • pp.476-485
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    • 2003
  • 본 연구의 목적은 막장전방에 파쇄대가 존재할 때 터널 3차원 내공변위를 여러 가지 방법으로 해석하여 변위의 변화 경향을 밝히고 지질변화를 예측하는 계측해석기법을 제시하는 것이다. 안정된 지하 암반에 터널을 굴착하게 되면, 터널 막장면을 포함한 무지보 굴착면 주위에 3차원적인 하중전이 현상이 나타나는데 막장 전방의 지반 상태가 변화하거나 연약 파쇠대층이 존재하면 특정한 변위 경향을 보이는 것으로 기존 연구결과 알려져 있다. 터널 천단부 축방향 변위/수직변위 비 등으로부터 터널 막장 전방에서 지반의 강성이 변화하는 불연속면의 존재를 예측할 수 있다. 그러므로, 시공중인 터널 내에서 3차원 절대 내공 변위를 측정하여 본 연구에서 제시된 계측해석 기법을 적용하면 터널 막장 전방의 지층변화나 파쇄대층의 존재를 사전에 예측할 수 있을 것으로 판단된다.

한국 중년 남성의 젊음 추구와 유행 스타일 변화 (Ageless Trend and the Fashionable Style of Korean Middle-Aged Men)

  • 이나현;하지수
    • 한국의류학회지
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    • 제39권5호
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    • pp.745-754
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    • 2015
  • This study analyzed Korean middle-aged men's fashionable styles according to ageless trends as their representative characteristic and deriving their special features from men's magazines. Literature and case studies were conducted together. The research findings are as follows. First, it showed uniformity, conformity, passive clothing selection and consumption in 1990s as characteristics of middle-aged men's wear by period. However, clothing became an expressive way to pursue individuality and an ageless trend gradually, and middle-aged men positioned themselves as subjects of a consumer market for men's wear after 2010 through active clothing selection and consumption. Second, along with a trend change preferring a comfortable and active to formal atmosphere, it showed that casual style became diversified and segmented gradually in Korean middle-aged men's ageless trend and fashionable style. Third, as for formative characteristic changes in middle-aged men's fashionable style by period, it contained a slim silhouette, bright and splendid colors and patterns, increase of light, active and functional materials, generalization of casual items and pursuit of individuality by various mix & match styles. Fourth, in Korean men's ageless trend and changing fashionable style, four kinds of special characteristics were derived that included a change of the traditional clothing symbolism, weakened conformity & pursuit of personality, obscured boundaries between age and wearing style, and active embracing of a trend.

2006 F/W Fur fashion trend 분석 (Fur trend analysis showed in 2006 Fall Winter collection)

  • 이은영
    • 자연과학논문집
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    • 제17권1호
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    • pp.79-87
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    • 2006
  • 지금 모피트렌드는 대중화와 디지털 트렌드에 힘입어 쇼킹하고 믹스드된 디자인과 실루엣이 컬렉션에 보이고 있다. 벌키하고 짧은 실루엣이 보이는데, 예전보다는 캐주얼에 믹스되기 때문에 그렇다. 배경에는 키덜트의 부상, 자연주의, 테크노캐주얼, 새로운 아방가르드로 표현되어진다. 이제 모피는 더 이상 클래식엘레강스(고현진, 2005) 아이템이 아니고, 보다 재미있고 차브(조주연, 2006)한 아이템으로 변해야 한다.

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섬유 신소재 개발 Trend에 대한 고찰 (An Analysis of New Textile Material Developmental Trend)

  • 이유경;김순심
    • 한국농촌생활과학회지
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    • 제6권1호
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    • pp.11-24
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    • 1995
  • The new textile materials may be defined as textile materials different from already existing ones in the physical and chemical structure, manufacturing process, or end-use property. The present time what is called the post-industrial society is characterized by rapid change and new technology. Also, textile materials have been changed rapidly and diversely in the post-industrial society than in any other periods. The study aimed to analyze the trend of new tektite materials development in Korea and to forecast the development trend in the future. To investigate the trend of new textile materials, various written materials and informations were collected from the manufacturers, textile related periodicals, and research journals, and they were analyzed. The period of analysis was from January 1992 to May 1995. The results of this research are as followings : (1) Mixed textile materiasl such as bicomponent fiber, blended yam and blended fabric were increased. (2) High technology has an important effect upon new textile material development. (3) functional textile materials were increased (4) The high value-added products were increased. (5) The naturalized textile materials were increased.

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