• Title/Summary/Keyword: Dry climate

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An Analysis of the Effect of Climate Change on Nakdong River Environmental Flow (낙동강 유역 환경유량에 대한 기후변화의 영향 분석)

  • Lee, A Yeon;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.273-285
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    • 2011
  • This study describes the modeling of climate change impact on runoff across southeast Korea using a conceptual rainfall-runoff model TANK and assesses the results using the concept of environmental flows developed by International Water Management Institute. The future climate time series is obtained by scaling the historical series, informed by 4 global climate models and 3 greenhouse gas emission scenarios, to reflect a $4.0^{\circ}C$ increase at most in average surface air temperature and 31.7% increase at most in annual precipitation, using the spatio-temporal changing factor method that considers changes in the future mean seasonal rainfall and potential evapotranspiration as well as in the daily rainfall distribution. Although the simulation results from different global circulation models and greenhouse emission scenarios indicate different responses in flows to the climate change, the majority of the modeling results show that there will be more runoff in southeast Korea in the future. However, there is substantial uncertainty, with the results ranging from a 5.82% decrease to a 48.15% increase in the mean annual runoff averaged across the study area according to the corresponding climate change scenarios. We then assess the hydrologic perturbations based on the comparison between present and future flow duration curves suggested by IMWI. As a result, the effect of hydrologic perturbation on aquatic ecosystems may be significant at several locations of the Nakdong river main stream in dry season.

Assessment of causality between climate variables and production for whole crop maize using structural equation modeling

  • Kim, Moonju;Sung, Kyungil
    • Journal of Animal Science and Technology
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    • v.63 no.2
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    • pp.339-353
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    • 2021
  • This study aimed to assess the causality of different climate variables on the production of whole crop maize (Zea mays L.; WCM) in the central inland region of the Korea. Furthermore, the effect of these climate variables was also determined by looking at direct and indirect pathways during the stages before and after silking. The WCM metadata (n = 640) were collected from the Rural Development Administration's reports of new variety adaptability from 1985-2011 (27 years). The climate data was collected based on year and location from the Korean Meteorology Administration's weather information system. Causality, in this study, was defined by various cause-and-effect relationships between climatic factors, such as temperature, rainfall amount, sunshine duration, wind speed and relative humidity in the seeding to silking stage and the silking to harvesting stage. All climate variables except wind speed were different before and after the silking stage, which indicates the silking occurred during the period when the Korean season changed from spring to summer. Therefore, the structure of causality was constructed by taking account of the climate variables that were divided by the silking stage. In particular, the indirect effect of rainfall through the appropriate temperature range was different before and after the silking stage. The damage caused by heat-humidity was having effect before the silking stage while the damage caused by night-heat was not affecting WCM production. There was a large variation in soil surface temperature and rainfall before and after the silking stage. Over 350 mm of rainfall affected dry matter yield (DMY) when soil surface temperatures were less than 22℃ before the silking stage. Over 900 mm of rainfall also affected DMY when soil surface temperatures were over 27℃ after the silking stage. For the longitudinal effects of soil surface temperature and rainfall amount, less than 22℃ soil surface temperature and over 300 mm of rainfall before the silking stage affected yield through over 26℃ soil surface temperature and less than 900 mm rainfall after the silking stage, respectively.

A Study on the Infrared Signature of a Naval Ship under the Marine Climate (함정 표면 적외선 신호에 대한 해양기상 영향분석)

  • Kim, Yoon-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.3
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    • pp.264-272
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    • 2012
  • A study on the IR(InfraRed) signature of a naval ship has been performed using well known IR signature analysis software, ShipIR/NTCS. Variations of the IR signature radiated from skins of a naval ship have been investigated according to the monthly averaged marine climate conditions. An unclassified destroyer model with and without applying the washdown system was applied to compare the influence on the signature under the background changes. The marine background models were created from the observed data by a buoy of Korea Meterological Administration(KMA). The sensitivity of the ship signature against the climate variables such as air temperature, sea temperature, relative humidity has been studied as well. The seasons which show extreme(max, min) skin signature change by whether the washdown is applied or not. The sensitivities of the air temperature and the sea temperature for a dry-ship reversed by applying the washdown on the ship surfaces.

A Study on the Temperature Reduction Effect of Street Green Area (도로변 가로녹지 유형이 기상에 미치는 영향)

  • Kim, Jeong-Ho;Choi, Won-Jun;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.26 no.12
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    • pp.1363-1374
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    • 2017
  • Global climate change caused by industrialization has caused abnormal weather conditions such as urban temperatures and tropical nights, urban heat waves, heat waves, and heavy rains. Therefore, the study tried to analyze climate conditions and weather conditions in the streets and analyze climate factors and meteorological factors that lead to inconvenience to citizens. In the case of trees, the overall temperature, surface temperature, solar irradiance, and net radiation were measured low, and the temperature was lower in the Pedestrian road than in roads. The dry bulb temperature, the black bulb temperature, and the wet bulb temperature for the thermal evaluation showed the same tendency. In the case of thermal evaluation, there was a similar tendency to temperature in WBGT, MRT, and UTCI, and varied differences between types. Although the correlation between the meteorological environment and the thermal environment showed a statistically significant significance, the difference between the measured items was not significant. The study found that the trees were generally pleasant to weather and thermal climate in the form of trees, and the differences were mostly documented.

A study on Applicability through Comparison of Weather Data based on Micro-climate with existing Weather Data for Building Performative Design (건물 성능디자인을 위한 미기후 기반 기상데이터의 기존 기상데이터와 비교를 통한 활용 가능성 연구)

  • Kim, Eon-Yong;Jun, Han-Jong
    • KIEAE Journal
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    • v.11 no.6
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    • pp.101-108
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    • 2011
  • The weather data has important role for performative building design. If the data location is close to building site, the result of performative design can be accurate. The data which have used nowadays in Korea are from U.S. Department of Energy (DOE) and Korea Solar Energy Society (KSES) but they cover only several locations in Korea which are 4 in DOE and 11 in KSES and there are opinions which it could be served building design efficiently even if the data are not enough. However the weather data for micro-climate are exist which are Green Building Studio Virtual Weather Station (GBS VWS) and Meteonorm weather data. Each weather data has different generation methods which are TMY2, TRY, MM5, and extrapolation. In this research, the weather date for climate are compared with DOE and KSES to check correlation. The result shows the value of correlation in Dry Bulb Temp. and Dew Point Temp. is around 0.9 so they have high correlation in both but in Wind Speed case the correlation(around 0.2) is not exist. In overall result, the data has correlation with DOE and KSES as the value of correlation 0.648 of GBS VW and 0.656 of Meteonorm. Even if the correlation value is not high enough, the patterns of difference in each weather element are similar in scatter plot.

Frequency analysis of nonidentically distributed large-scale hydrometeorological extremes for South Korea

  • Lee, Taesam;Jeong, Changsam;Park, Taewoong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.537-537
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    • 2015
  • In recent decades, the independence and identical distribution (iid) assumption for extreme events has been shown to be invalid in many cases because long-term climate variability resulting from phenomena such as the Pacific decadal variability and El Nino-Southern Oscillation may induce varying meteorological systems such as persistent wet years and dry years. Therefore, in the current study we propose a new parameter estimation method for probability distribution models to more accurately predict the magnitude of future extreme events when the iid assumption of probability distributions for large-scale climate variability is not adequate. The proposed parameter estimation is based on a metaheuristic approach and is derived from the objective function of the rth power probability-weighted sum of observations in increasing order. The combination of two distributions, gamma and generalized extreme value (GEV), was fitted to the GEV distribution in a simulation study. In addition, a case study examining the annual hourly maximum precipitation of all stations in South Korea was performed to evaluate the performance of the proposed approach. The results of the simulation study and case study indicate that the proposed metaheuristic parameter estimation method is an effective alternative for accurately selecting the rth power when the iid assumption of extreme hydrometeorological events is not valid for large-scale climate variability. The maximum likelihood estimate is more accurate with a low mixing probability, and the probability-weighted moment method is a moderately effective option.

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Characteristics of Macroinvertebrates Food Webs affected by Dry Channel in an Intermittent Stream System of the Echi River in Japan

  • Shin, Hyun-Seon;Nozomi, Amahashi;Na, Young-Eun;Park, Hong-Hyun;Cho, Kwang-Jin;Seo, Ye-Ji;Osamu, Mitamura
    • Journal of Climate Change Research
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    • v.6 no.3
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    • pp.167-173
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    • 2015
  • The purpose of study is to identify trophic pathways from organic matter to macroinvertebrates in terms of the consumer and to characterize the food webs in an intermittent stream system of the Echi River in Japan. The ${\delta}^{13}C$ values of macroinvertebrates and their potential food sources indicated the scraper (Psephenoides spp., Ecdyonurus levis) and collector-gatherer (Ephemera strigata, Paraleptonphlebia chocolata) feed on periphyton and POM (particulate organic matter) in situ. Davidius lunatus, and Hexatoma spp., which were identified as predators, may feed upon Ephemera strigata and Stenelmis larvae, respectively. At station characterized by seepage water, the ${\delta}^{15}N$ values of Ecdyonurus levis, Lymnaea auricularia, and Rhyacophila nigrocephala larva probably showed relatively lower values according to its diets. Even in homogenous species, the trophic pathways of macroinvertebrates in situ exhibited considerable variation; this reflected the trophic pathways from organic matter to the consumer depending on habitat characteristics in stream.

The Influence of Occupational Stress in Dry Mouth and Self-Diagnosed Oral Symptoms on Workers (근로자의 직무스트레스가 구강건조감 및 구강증상에 미치는 영향)

  • Cho, Hye Jin;Cho, Min Hee;Jo, Yoon Ji;Jang, Young Eun;Jeon, Eun Hee;Jeong, Bok Lim;Jeong, Yoon Sun;Cha, Hye Kyung;Choi, Young Joo;Han, In Sung;Hwang, Ji Young;Hong, Min-Hee
    • Journal of dental hygiene science
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    • v.12 no.6
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    • pp.634-643
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    • 2012
  • Job stress is emerging as one of major issues related to oral health in modern society that has increasingly been complicated and diversified. The purpose of this study was to examine the job stress and dry mouth of workers and their self-diagnosed oral symptoms in an attempt to determine the relationship between job stress and dry mouth. The subjects in this study were 366 workers, and a survey was conducted to June 1 to 20, 2012. Whether there would be any differences in dry mouth and self-diagnosed oral symptoms according to job stress was analyzed, and it's found that there were significant differences in dry mouth according to organizational climate. And oral symptoms made significant differences to job demand, interpersonal conflicts, organizational system, lack of reward and job stress. There was a positive correlation between dry mouth and organizational climate, and oral symptoms had a significant correlation to job demand, interpersonal conflicts, job insecurity, organizational system, job stress and dry mouth. Organizational climate and lack of reward had a significant impact on dry mouth, and oral symptoms were under the significant influence of dry mouth, job insecurity and organizational system.

Mapping the Spatial Distribution of IRG Growth Based on UAV

  • Na, Sang-Il;Park, Chan-Won;Kim, Young-Jin;Lee, Kyung-Do
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.495-502
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    • 2016
  • Italian Ryegrass (IRG), which is known as high yielding and the highest quality winter annual forage crop, is grown in mid-south area in Korea. The objective of this study was to evaluate the use of unmanned aerial vehicle (UAV) for the monitoring IRG growth. Unmanned aerial vehicle imagery obtained from middle March to late May in Nonsan, Chungcheongnam-do. Unmanned aerial vehicle imagery corrected geometrically and atmospherically to calculate normalized difference vegetation index (NDVI). We analyzed the relationships between $NDVI_{UAV}$ of IRG and biophysical measurements such as plant height, fresh weight, and dry weight over an entire IRG growth period. The similar trend between $NDVI_{UAV}$ and growth parameters was shown. Correlation analysis between $NDVI_{UAV}$ and IRG growth parameters revealed that $NDVI_{UAV}$ was highly correlated with fresh weight (r=0.988), plant height (r=0.925), and dry weight (r=0.853). According to the relationship among growth parameters and $NDVI_{UAV}$, the temporal variation of $NDVI_{UAV}$ was significant to interpret IRG growth. Four different regression models, such as (1) Linear regression function, (2) Linear regression through the origin, (3) Power function, and (4) Logistic function were developed to evaluate the relationship between temporal $NDVI_{UAV}$ and measured IRG growth parameters. The power function provided higher accurate results to predict growth parameters than linear or logistic functions using coefficient of determination. The spatial distribution map of IRG growth was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to power function. From these results, $NDVI_{UAV}$ can be used as a new tool for monitoring IRG growth.

A Study on the Style of Clothing of Turk (돌궐 의복 형태 연구)

  • Yang, Ye-Eun;Chae, Keum-Seok
    • Journal of the Korea Fashion and Costume Design Association
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    • v.19 no.2
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    • pp.63-78
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    • 2017
  • The purposes of this study was to study Turkic clothing traditions as a way to shed light on cultural development via the interactions among different tribes along the Silk Road, the close correlations between the surroundings of the Turks and their costumes, and the root of Turkic culture through literature studies and empirical studies. The study results are as follows. First, the Turks were nomadic equestrian tribes in the north that dominated the cold dry steppes from the $6^{th}$ to $8^{th}$ century A.D., when they expanded their influence to Dongbei, China to the east, and Turkistan (Central Asia) to the west. The Turks formed a nomadic lifestyle and culture suited to a cold dry climate, and interacted with various other tribes via the Silk Road, while exchanging and sharing different cultural aspects. Second, given that the Turkic garments constitute a two-piece style, which is a category of the basic nomadic costume of northern tribes, and that the artifact materials manifest jackets, overcoats, pants and skirts, the garments are categorized into tops and bottoms. The tops are sub-categorized into jackets and overcoats. The bottoms are sub-categorized into pants and skirts. In light of the necklines of tops, jackets have round necklines, while overcoats have V-necklines, round necklines and lapel collars. The bottoms include narrow-legged pants, wide-legged pants and closed-hem pants. Drapery skirts are worn at the waist. Third, the Turkic V-neckline overcoat is comparable to the Huns' silk overcoat, which illustrates the ethnic link between the two tribes. Also, the Turkic narrow- and wide-legged pants are consistent with the Huns' silk pants discovered in Noin Ula. The Turkic costumes are mostly tight fitting, suitable for the nomadic lifestyle in a cold, dry climate. Also, additional patches must be attached to the crotch points of pants due to the equestrian lifestyle.

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