• Title/Summary/Keyword: Weather Changes

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Sorting and Abrasion Processes on Gravel Beach of Jeongdo-ri, Wando, Korea (한국 남해 완도 정도리 자갈 해빈의 퇴적작용)

  • 고영이;박용안;최강원
    • The Korean Journal of Quaternary Research
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    • v.7 no.1
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    • pp.27-39
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    • 1993
  • The shingle beach as a typical pocket beach located in Jeongdo-ri, Wando, Cheolanam-do, Korea has been investigated in terms of textural characteristics, mainly gravel shape and roundness. In the Jeongdo-ri gravel beach, changes of beach profile after storm weather and textural parameters of gravels were observed and measured from May 1992 to March 1993. Beach profile is divided into two different Fair-weather zone and Storm-weather zone influenced by dynamic condition of wave energy. The former is affected by wave and tide under fair-weather condition, the latter seems to be formed under storm-weather condition. Each zone comprises a series of beach faces and berms formed by continuous sedimentary processes of swash, overwash and backwash. Storm-weather zone is subdivided into three groups having a pair of beach face and berm respectively. Mean sizes of berm gravel(45.5 mm -123.6 mm) are coarser than gravels of beach face (36.8 mm - 78.3 mm) in fair-weather zone. On the other hand, in storm-weather zone, gravels of berms (33.1 mm -82.5 mm) are finer than those of beachfaces (46.2 mm - 105.2 mm). The proportion of disc shaped gravels of berm (50.0% - 58.5 %) is higher than that of beachface (45.9 % - 51.3 %) in each subzone except C-group of storm-weather zone. And the proportion of the equant shaped gravel increases about up to 10% seaward. Therefore, shore-normal distribution of gravels seems to be affected by shape and size sorting effects. Shore-parallel distribution pattern of gravel shape is more distinctive than size distribution patterns. That is, disc and blade shaped particles decrease up to 20% and 13% respectively, and equants increase up to 34% to the westward. Gravels plotted on Sneed and Folk's triangular diagram are more compacted and elongated with decreasing size. Therefore primary gravels are shaped by characteristics of country rock e.g. cleavage, joint etc., and secondary are affected by sorting and size-controlled process evolution by wave action.

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Patterns on Sewer Transfer Flow for Rain Weather Period in the Area with Combined Sewer System for the Management of TMDLs (수질오염총량관리 합류식지역의 우기시 관거이송 변화유형)

  • Park, Jun Dae;Oh, Seung Young;Kim, Ji-Tae
    • Journal of Korean Society on Water Environment
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    • v.26 no.6
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    • pp.1008-1015
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    • 2010
  • Discharged pollution load is varied as rainfall changes in the area with combined sewer system. Changes in discharged pollution load are directly related with those of sewer transfer flow. Therefore, it is important to identify the pattern of sewer transfer flow for the analysis of changes in discharged pollution load. This study reviewed the type of distribution of sewer transfer flow for 17 sewage treatment plants and developed simple formular to estimate sewer transfer flow as rainfall changes. 11 facilities showed to have some relation with rainfall in the change of sewer transfer flow but 6 facilities to have no relation. Relationships between rainfall amount and sewer transfer flow showed that 6 facilities out of 11 had relatively strong relationships above R2=0.5, which were considered to be affected directly by rainfall changes. The formular which explain the relationship between rainfall and sewer transfer flow can be applied in the analysis of rainfall effects on discharged pollution load, therefore, the more appropriate evaluation will be done.

Market Trends in Tractor Hydraulid Fluids

  • Mochizuki Akihiro
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2005.10a
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    • pp.67-83
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    • 2005
  • [ $\blacklozenge$ ] Farm equipment market very cyclic - weather, economic factors, import/export markets $\blacklozenge$ Mergers of companies continuing $\blacklozenge$ Major Tractor OEMs have lubricant specifications $\blacksquare$ Their own house branded THF $\blacksquare$ Constant review reflecting the changes in equipment $\blacksquare$ Less interest in approving outside additives/oils for others $\blacklozenge$ Future THF lubricant market $\blacksquare$ ' Universal' THF may five way to individual products for each OEM $\blacksquare$ Sumps are getting smaller $\blacksquare$ Increased use of hydraulic system vs. mechanical $\blacklozenge$ Additive companies will need to meet many challenges

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Application Study of Reinforcement Learning Control for Building HVAC System

  • Cho, Sung-Hwan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.14 no.4
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    • pp.138-146
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    • 2006
  • Recently, a technology based on the proportional integral (PI) control have grown rapidly owing to the needs for the robust capacity of the controllers from industrial building sectors. However, PI controller generally requires tuning of gains for optimal control when the outside weather condition changes. The present study presents the possibility of reinforcement learning (RL) control algorithm with PI controller adapted in the HVAC system. The optimal design criteria of RL controller was proposed in the environment chamber experiment and a theoretical analysis was also conducted using TRNSYS program.

Analysis of Watershed Runoff and Sediment Characteristics due to Spatio-Temporal Change in Land Uses Using SWAT Model (SWAT 모형을 이용한 시.공간적 토지 이용변화에 따른 유량 및 유사량 특성분석)

  • Shin, Yong-Chul;Lim, Kyoung-Jae;Kim, Ki-Sung;Choi, Joong-Dae
    • KCID journal
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    • v.14 no.1
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    • pp.50-56
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    • 2007
  • In this study, the Soil and Water Assessment Tool (SWAT) model was used to assess spatiotemporal effects on watershed runoff and sediment characteristics due to land uses changes from 1999 to 2002 at the small watershed, located in Chuncheon-si, Gangwon province. The annual average flow rate of Scenario I (long-term simulation using land use of 1990), II (long-term simulation using land use of 1996), III(long-term simulation using land use of 200) and IV(simulation using land use of 1990, 1995, and 2000) in long-term simulation) using the SWAT model were 29,997,043 m3, 29,992,628 m3, 29,811,191 m3 and 29,931,238 m3, respectively. It was shown that there was no significant changes in estimated flow rate because no significant changes in land uses between 1990 and 2000 were observed. The annual average sediment loads of Scenarios I, II, III and IV for 15 year period were 36,643 kg/ha, 45,340 kg/ha , 27,195 kg/ha and 35,545 kg/ha, respectively. The estimated annual sediment loads from Scenarios I, II, and III, were different from that from the scenario IV, considering spatio-temporal changes in land use and meterological changes over the years, by 10%, 127%, and temporal changes in land use and meterological changes over the years, by 10%, 127%, and 77%. This can be explained in land use changes in high soil erosion potential areas, such as upland areas, within the study watershed. The comparison indicates that changes in land uses upland areas, within the study watershed. The comparison indicates that changes in land uses can affect on sediment yields by more than 10%, which could exceed the safety factor of 10% in Total Maximum Daily Loads (TMDLs). It is, therefore, recommended that not only the temporal analysis with the weather input data but also spatial one with different land uses need to be considered in long-term hydrology and sediment simulating using the SWAT model

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A Study on the Change of the Urban Heat Island Structure in Busan Metropolitan Area, Korea (부산지역의 도시열섬 구조 변화에 관한 연구)

  • Kim, Hyunsu;Seok, Hyun-Bae;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1807-1820
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    • 2014
  • The spatial and temporal changes of the annual mean urban heat island(UHI) intensity were investigated using near surface temperature data measured at 16 automatic weather systems(AWS) in Busan metropolitan area(BMA) during the 11-yr period, from 2000 to 2010. For nighttime, the annual mean UHI intensity at Dongnae(U1) in 2000 was weaker than it in 2010. However the change of the annual mean UHI intensity at Daeyeon(U2) during 11 years was different from it at U1. The annual frequency of the UHI intensity over $5^{\circ}C$ considerably increased at U2 and decreased at U1 during 11 years. The center of the UHI also spatially shifted southward with Daeyeon and Haeundae in BMA. It would be caused by the increase of urban area, population-density and transportation near U2 and by the decrease of them near U1. We found that the spatial and temporal differences of the UHI intensity have coincided with changes of land-use, population density and transportation in BMA.

The Study on the ${\ulcorner}$Sun Gi Il Il Bun Wi Sa Si(順氣一日分爲四時)${\lrcorner}$ of the ${\ulcorner}$Young Chu(靈樞)${\lrcorner}$ ("영추.순기일일분위사시(靈權.順氣一日分爲四時)"에 대한 연구(硏究))

  • Kim, Young-Ha;Ruk, Sang-Won
    • Journal of Korean Medical classics
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    • v.18 no.1 s.28
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    • pp.33-48
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    • 2005
  • The purpose of this study is that translates ${\ulcorner}$Sun Gi Il Il Bun Wi Sa Si${\lrcorner}$ in the ${\ulcorner}$Young Chu(靈樞)${\lrcorner}$ as a modern words because it is hard to understand which was written by classical words. We revised the original text with the 7 other classic books and classified annotations of the 6 annotated books according to the similar contents. We classified this volume by 3 chapters, and added Hangul suffixes to the original text. The Five types of changes(五變) in the second chapter is meaning to the mutual relationships among the Five viscera and Color, Time, Day, Note, Taste. The word order of contents in the second chapter must be unified follow the Color, Time, Day, Note, Tastes. The Five types of changes in the third chapter must be revise the Five types of diseases(五病) on the bases of the ${\ulcorner}$You Kyoung(類經)${\lrcorner}$.

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The Impacts of Climate Change on Paddy Water Demand and Unit Duty of Water using High-Resolution Climate Scenarios (고해상도 기후시나리오를 이용한 논용수 수요량 및 단위용수량의 기후변화 영향 분석)

  • Yoo, Seung-Hwan;Choi, Jin-Yong;Lee, Sang-Hyun;Oh, Yun-Gyeong;Park, Na-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.54 no.2
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    • pp.15-26
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    • 2012
  • For stable and sustainable crop production, understanding the effects of climate changes on agricultural water resources is necessary to minimize the negative effects which might occur due to shifting weather conditions. Although various studies have been carried out in Korea concerning changes in evapotranspiration and irrigation water requirement, the findings are still difficult to utilize fordesigning the demand and unit duty of water, which are the design criteria of irrigation systems. In this study, the impact analysis of climate changes on the paddy water demand and unit duty of water was analyzed based on the high resolution climate change scenarios (specifically under the A1B scenario) provided by the Korea Meteorological Administration. The result of the study indicated that average changes in the paddy water demand in eight irrigation districts were estimated as -2.4 % (2025s), -0.2 % (2055s), and 3.2 % (2085s). The unit duty of water was estimated to increase on an average within 2 % during paddy transplanting season and within 5 % during growing season after transplanting. This result could be utilized for irrigation system design, agricultural water resource development, and rice paddy cultivation policy-making in South Korea.

A Fingerprint of Global Warming Appeared in Winter Precipitation across South Korea (우리나라 겨울철 강수에 나타난 지구온난화의 징후)

  • Choi, Gwang-Yong;Kwon, Won-Tae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.992-996
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    • 2008
  • In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

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