• Title/Summary/Keyword: prediction change

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Future water quality analysis of the Anseongcheon River basin, Korea under climate change

  • Kim, Deokwhan;Kim, Jungwook;Joo, Hongjun;Han, Daegun;Kim, Hung Soo
    • Membrane and Water Treatment
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    • v.10 no.1
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    • pp.1-11
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    • 2019
  • The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) predicted that recent extreme hydrological events would affect water quality and aggravate various forms of water pollution. To analyze changes in water quality due to future climate change, input data (precipitation, average temperature, relative humidity, average wind speed and sunlight) were established using the Representative Concentration Pathways (RCP) 8.5 climate change scenario suggested by the AR5 and calculated the future runoff for each target period (Reference:1989-2015; I: 2016-2040; II: 2041-2070; and III: 2071-2099) using the semi-distributed land use-based runoff processes (SLURP) model. Meteorological factors that affect water quality (precipitation, temperature and runoff) were inputted into the multiple linear regression analysis (MLRA) and artificial neural network (ANN) models to analyze water quality data, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (T-N) and total phosphorus (T-P). Future water quality prediction of the Anseongcheon River basin shows that DO at Gongdo station in the river will drop by 35% in autumn by the end of the $21^{st}$ century and that BOD, COD and SS will increase by 36%, 20% and 42%, respectively. Analysis revealed that the oxygen demand at Dongyeongyo station will decrease by 17% in summer and BOD, COD and SS will increase by 30%, 12% and 17%, respectively. This study suggests that there is a need to continuously monitor the water quality of the Anseongcheon River basin for long-term management. A more reliable prediction of future water quality will be achieved if various social scenarios and climate data are taken into consideration.

60 Years of Korean Meteorological Society on Climate Change (기후변화 연구에 관한 한국기상학회 60년사)

  • Joong-Bae Ahn;Young-Hwa Byun;Dong-Hyun Cha
    • Atmosphere
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    • v.33 no.2
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    • pp.155-171
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    • 2023
  • This paper aims to examine from various perspectives how domestic research studies and projects related to climate change have been conducted to mark the 60th anniversary of the Korean Meteorological Society (KMS). The 『50-year History of the Korean Meteorological Society』, published more than a decade ago, has never dealt with the history of development of individual fields of meteorology such as climate change. Therefore, it is of significance to look at the history of research activities and studies achieved by KMS members in the area of climate change over the past 60 years. The research on climate change in KMS is classified by era from the beginning to the latest and the contents are examined by major research projects at that time. During the past 60 years, climatological research in KMS has been mainly focused on general climate, synoptic climate, and applied climate (urban climate) until the 2000s. However, since the 1990s, climate change has become an important area for climate research. The 2000s are the beginning era of climate change research, since the major projects and researches for climate change has begun in the period. The 2010s can be a time when climate change prediction and monitoring are expanded and refined to meet the rapidly increasing demands for climate information from a wide range of areas. We concluded that the development of the research capabilities of the society over the past 60 years, in particular in the past two decades, in the field of climate change research is remarkable.

Study on the Prediction of Surface Color Change of Cultural Properties Materials by Fog Occurrence (안개 발생에 따른 문화재 표면의 색 변화 예측 연구)

  • Han, Ye Bin;Park, Sang Hyeon;Yu, Ji A;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.32 no.4
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    • pp.491-500
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    • 2016
  • Fog is atmospheric in which tiny drops of water vapor are suspended in the air near the ground. Its form, occurrence, etc., change according to the temperature, relative humidity, wind and geographical features of the space around it. In particular, fog tends to occur near a source of water because of temperature and relative humidity difference. These days, climate change is increasingly affecting the occurrence of fog. Therefore the purpose of this study was to investigate how fog affects materials that are part of our cultural properties through outdoor exposure tests and artificial degradation. The degradation evaluation of materials as a function of fog occurrence frequency, showed that the color of metals changed noticeably, whereas dyed silk and Dancheong showed degradation on the surface and color differences but no particular tendencies. Therefore, damage prediction by color differences as a function of fog occurrence frequency was based on metal samples, which showed constant color differences. Through a comparison of the predictive value and color difference by outdoor exposure, the accuracy and applicability of the damage prediction formula was confirmed. If a more complex damage prediction formula is created, it is expected that prediction of the degree of material damage in the field would be possible.

Prediction of the Optimal Growth Site and Estimation of Carbon Stocks for Quercus acuta in Wando Area (완도지역의 붉가시나무 생육 적지예측 및 탄소저장량 추정)

  • Hwang, Jeong-Sun;Kang, Jin-Teak;Son, Yeong-Mo;Jeon, Hyun-Sun
    • Journal of Climate Change Research
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    • v.6 no.4
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    • pp.319-330
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    • 2015
  • This study was carried out to predict the optimal growth site and estimate carbon stocks of Quercus acuta, evergreen broad-leaved trees in warm temperate zone according to climate change. The criterion for the optimal site prediction was created by quantification method with quantitative and qualitative data, collected from growth factors of stands and environmental factors of survey sites of 42 plots in Q. acuta by study relationship between growth of tree and site environmental factors. A program for the optimal site prediction was developed by using GIS engine tools. To prediction of the suitable growth site of Quercus acuta, developed program in this study applied to Wando in Jeollanam-do, distributing a various evergreen bread-leaved trees of warm temperate zone. In the results from analysis of the optimal site prediction on Q. acuta, the characteristics of the optimal site showed as follows; site environmental features of class I (the best site class for Q. acuta) was defined as 401 ~ 500 m of altitude, $21{\sim}25^{\circ}$ of slope with above hillside, residual of deposit convex of slope type with west of aspect. The area and carbon stocks of optimal site prediction by class for Q. acuta in classI showed 147.1 ha (2.5%), total 316.5 tC/ha, total $1,161tCO_2/ha/yr$ of class I, 2,703.5 ha (46.3%), total 5,817.4 tC/ha, total $21,331tCO_2/ha/yr$ of class II, 2,845.5 ha (48.6%), total 6,123.0 tC/ha, total $2,845.5tCO_2/ha/yr$ of class III and 153.7 ha (2.6%), total 330.7 tC/ha, total $1,213.7tCO_2/ha/yr$ of class IV.

The Study of De-orbit Time Prediction Using Temperature Change of Geostationary Satellite Propellant System (정지궤도위성 추진시스템의 온도변화를 이용한 위성폐기시점 추정연구)

  • Park Eung Sik;Park Bong Kyu;Han Cho Young;Kim Yong Min
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • v.y2005m4
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    • pp.5-10
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    • 2005
  • The geostationary satellite propulsion system has thermistors which can measure liquid propellant temperature at tanks, pipes and etc. In the satellite propulsion system with several tanks, the propellant in the tanks is moved by temperature change and this temperature pattern is constant. In this paper, the temperature change pattern of KOREASAT 1 propulsion system is compared and the prediction study of pressurant inflow using temperature change of geostationary satellite propulsion system is described.

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A Simulation Study on Future Climate Change Considering Potential Forest Distribution Change in Landcover (잠재 산림분포 변화를 고려한 토지이용도가 장래 기후변화에 미치는 영향 모사)

  • Kim, Jea-Chul;Lee, Chong Bum;Choi, Sungho
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.105-117
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    • 2012
  • Future climate according to land-use change was simulated by regional climate model. The goal of study was to predict the distribution of meteorological elements using the Weather Research & Forecasting Model (WRF). The KME (Korea Ministry of Environment) medium-category land-use classification was used as dominant vegetation types. Meteorological modeling requires higher and more sophisticated land-use and initialization data. The WRF model simulations with HyTAG land-use indicated certain change in potential vegetation distribution in the future (2086-2088). Compared to the past (1986-1988) distribution, coniferous forest area was decreased in metropolitan and areas with complex terrain. The research shows a possibility to simulate regional climate with high resolution. As a result, the future climate was predicted to $4.5^{\circ}$ which was $0.5^{\circ}$ higher than prediction by Meteorological Administration. To improve future prediction of regional area, regional climate model with HyTAG as well as high resolution initial values such as urban growth and CO2 flux simulation would be desirable.

Statistical Estimate and Prediction Values with Reference to Chronological Change of Body Height and Weight in Korean Youth (한국인 청소년 신장과 체중의 시대적 변천에 따른 통계학적 추정치에 관한 연구)

  • 강동석;성웅현;윤태영;최중명;박순영
    • Korean Journal of Health Education and Promotion
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    • v.13 no.2
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    • pp.130-166
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    • 1996
  • As compared with body height and body weight by ages and sexes, by means of the data reported under other researchers from 1967 to 1994 for 33 years, this study obtained the estimate value of body height and body weight by ages and sexes for the same period, and figured out prediction value of body height and body weight in the ages of between 6 and 14 from 1995 to 2000. These surveys and measurements took for one year from October 1st 1994 to September 30th. As shown in the 〈Table 1〉, in order to calculate the establishment, estimate value and prediction value of the chronological regression model of body height and body weight, by well-grounded 17 representative research papers, this research statistically tested propriety of liner regression model by the residual analysis in advance of being reconciled to simple liner regression model by the autonomous variable-year and the subordinate variable-body weight and measured prediction value, theoretical value from 1962 to 1994 by means of 2nd or 3rd polynomial regression model, with this redult did prediction value from 1995 to 2000. 1. Chronological Change of Body Height and Body Weight The analysis result from regression model of the chronological body height and body weight for the aged 6 - 16 in both sexes ranging from 1962 to 1994, corned from the 〈Table 2-20〉. On the one hand, the measurement value of respective researchers had a bit changes by ages with age growing, but the other hand, theoretical value, prediction value showed the regular increase by the stages and all values indicated a straight line on growth and development with age growing. That is, in case of the aged 6, males had 109.93cm in 1962 and females 108.93cm, but we found the increase that males had 1I8.0cm, females 1I3.9cm. In theoretical value, prediction value, males showed the increase from 109.88cm to 1I7.89cm and females from 109.27cm to 1I5.64cm respectively. There was the same inclination toward all ages. 2. Comparision to Measurement Value and Prediction Value of Body Height and Body Weight in 1994 As shown in the 〈Table 21〉, in case of body height, measurement value and prediction value of body height and body weight by ages and sexes almost showed the similiar inclination and poor grade, in case of body weight, prediction value in males had a bit low value by all ages, and prediction value in females had a high value in adolescence, to the contrary, a low value in adult. 3. Prediction Value of Body Height and Body Weight from 1995 to 2000 This research showed that body height and body weight remarkably increased in adolescence but slowly in adult. This study represented that Korean physique was on the increase and must be measured continually hereafter.

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Prediction-based Dynamic Thread Pool System for Massively Multi-player Online Game Server

  • Ju, Woo-Suk;Im, Choong-Jae
    • Journal of Korea Multimedia Society
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    • v.12 no.6
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    • pp.876-881
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    • 2009
  • Online game servers usually has been using the static thread pool system. But this system is not fit for huge online game server because the overhead is always up-and-down. Therefore, in this paper, we suggest the new algorithm for huge online game server. This algorithm is based on the prediction-based dynamic thread pool system. But it was developed for web servers and every 0.1 seconds the system prediction the needed numbers of threads and determine the thread pool size. Some experimental results show that the check time of 0.4 seconds is the best one for online game server and if the number of worker threads do not excess or lack to the given threshold then we do not predict and keep the current state. Otherwise we apply the prediction algorithm and change the number of threads. Some experimental results shows that this proposed algorithm reduce the overhead massively and make the performance of huge online game server improved in comparison to the static thread pool system.

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Characteristics and Prediction of Shear Strength for Unsaturated Residual Soil (풍화잔적토의 불포화전단강도 예측 및 특성연구)

  • 이인모;성상규;양일순
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.377-384
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    • 2000
  • The characteristics and prediction model of the shear strength for unsaturated residual soils was studied. In order to investigate the influence of the initial water content on the shear strength, unsaturated triaxial tests were carried out varying the initial water content, and the applicability of existing prediction models for the unsaturated shear strength was testified. It was shown that the soil - water characteristic curve and the shear strength of the unsaturated soil varied with the change of the initial water content. A sample compacted in the lower initial water content needs a higher suction to get the same degree of saturation while the shear strength of a sample with the lower initial water content displays a lower value. In order to apply the existing prediction models of the unsaturated shear strength to granite residual soils, a correction coefficient, α, on the internal friction angle, ø'was added.

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The Prediction Method with accumulated LOTTO numbers (당첨 로또 번호의 누적 데이터를 활용한 예측 방안)

  • Kim, Do-Goan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2017.05a
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    • pp.131-133
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    • 2017
  • To predict the future, the accumulated data can be fundamental basic. While many prediction methods based on contingency theory have been used, the prediction of LOTTO number can not be based on the contingency theory. But, this research attempts to suggest the method to predict LOTTO numbers through using the change of the prediction capability on accumulated data.

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