• Title/Summary/Keyword: 계절 차이

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Outlook on Variation of Water Resources in Korea under SRES A2 Scenario (A2 시나리오에 따른 국내 수자원의 변동성 전망)

  • Bae, Deg-Hyo;Jung, Il-Won;Lee, Byong-Ju
    • Journal of Korea Water Resources Association
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    • v.40 no.12
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    • pp.921-930
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    • 2007
  • The objective of this study is to present temporal-spatial variation of water resources on climate change impacts using the IPCC SRES A2 scenario and dynamical downscaling of the results (using the MM5 model with a resolution of 27km by 27km) at 139 sub-basins in Korea. The variation of runoff shows differences in the change of rate according to the each sub-basins and analysis durations. It has increased in the sub-basins located in Han river basin and east part of it, the other basins have decreased. In seasonal analysis, runoff in autumn and winter have increased, while in spring and summer have decreased. The results of frequency analyzing classified runoff(Low flow(Q$\leq$5mm), Normal flow(5$\geq$100mm)) show that low flow increase in most of the sub-basins for 2031-2060 and 2061-2090. In the case of high flow, it have higher frequency ranging from -100% to 500% than low flow. Regardless of the variation of mean runoff, maximum discharge appeared to be increase in process of time. The regression method is used to figure out the relationship between the rate of runoff change and mean temperature, mean precipitation under A2 scenario. The mean actual evapotranspirations from the regression equations increased by 3.4$\sim$5.3% for the change of $1^{\circ}C$. Also, for the precipitation change of $\pm$10%, runoff variety range is -18.2$\sim$+12.4% in Han River, -21.6$\sim$+14.6% in Nakdong River, -17.5$\sim$+11.5% in Gum River, -18.4$\sim$+10.6% in Sumjin River, -19.9$\sim$+12.7% Youngsan River basin.

A Study on Natural Scene Figuration Possibility - Centering around Gyeongnam Area(Namhae Gacheon Village, Sancheong Imchon Village, Hamyang Doma Village) Rice Terraces - (자연경관 조형화 가능성에 관한 연구 - 경남지역(남해가천마을, 산청임촌마을, 함양도마마을) 다랑이논을 중심으로 -)

  • Youn, Kyung-Sook;Lee, Jae-Keun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.1
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    • pp.113-119
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    • 2010
  • This study examined figurative characters of rice terraces, and is intended to seek figurative possibility of a natural scene by selecting Gyeongnam Area Namhae Gacheon rice terraces, Sancheong Imcheon rice terraces and Hamyang Macheon rice terraces through an analysis of the target land. As a theoretical background, studies of a natural scene and figuration-related literature were looked into, and for figuring a natural scene on the basis of the results, the character of the topography of rice terraces was divided into 9 items as follows by generalizing the inspiration obtained from the natural scenic character and spatial character of rice terraces represented from the topography: (1) Inclination showing the degree of the slope of rice terraces, (2) The bending showed by unevenness of the edge line of rice terraces, (3) The degree of parallelism of the up-and-down edge line, (4) The size of the width of the section of each rice terrace, (5) The area of the total rice terraces, (6) Step gap that indicates the difference of high and low of the up-and-down small rice terraces, (7) Figuration as an image represented by the external form of the total rice terraces, (8) Naturalness and artificiality kept by the total scene, (9) Softness of cornerstones or soil that forms small rice terraces, an atmosphere produced by the total scenes, etc. The results of analysis made through GIS, with rice terraces of Gyeongnam Namhae, Sancheong and Hamyang Area as the target land, are as follows. First, the steeper the inclination is, the higher the step difference of cornerstones becomes, and the steeper the inclination, the narrower the area and width become, so that it could be known that, in rice terraces, inclination is proportional to step difference and the area is inversely proportional to the width. Second, it is considered that line showed in rice terraces, area elements and reiteration, repeated changes, and changes in the scene affected by the surrounding environment including those according to season can be converted into a variety of images according to an individual disposition. Third, it was decided that it is possible to figure repetitive composition and directivity, motility, order and change, etc. into a common type drawn from each target land. This paper, as a study of basic materials for expressing figuration in an environment field, investigated and analyzed the surrounding environment of the target land, and is significant in that it attempted the possibility of being able to generalize the environmental beauty of the target land as one figurative element. More precise studies are expected to be made later.

Estimate of Heat Flux in the East China Sea (동지나해의 열속추정에 관한 연구)

  • KIM Young-Seup
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.1
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    • pp.84-91
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    • 1996
  • Heat flux of the East China Sea was estimated with the bulk method, the East China mount based on the marine meteorological data and cloud amount data observed by a satellite. Solar radiation is maximum in May and minimum in December. Its amount decreases gradually southward during the winter half year (from October to March), and increases northward during the summer half year (from April to September) due to the influence of Changma (Baiu) front. The spatial difference of long-wave radiation is relatively small, but its temporal difference is quite large, i.e., the value in February is about two times greater than that in July. The spatial patterns of sensible and latent heat fluxes reflect well the effect of current distribution in this region. The heat loss from the ocean surface is more than $830Wm^{-2}$ in winter, which is five times greater than the net radiation amount during the same period, The annual net heat flux is negative, which means heat loss from the sea surface, in the whole region over the East China Sea. The region with the largest loss of more than $400Wm^{-2}$ in January is observed over the southwestern Kyushu. The annual mean value of solar radiation, long-wave radiation, sensible and latent heat fluxes are estimated $187Wm^{-2},\;-52Wm^{-2},\;-30Wm^{-2}\;and\;-137Wm^{-2}$, respectively, consequently the East China Sea losses the energy of $32Wm^{-2}(2.48\times10^{13}W)$. Through the heat exchange between the air and the sea, the heat energy of $0.4\times10^{13}W$ is supplied from the air to the sea in A region (the Yellow Sea), $2.1\times10^{13}W$ in B region (the East China Sea) and $1.7\times10^{13}W$ in C region (the Kuroshio part), respectively.

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Dynamics of the Community of Phytoplankton and Periphytic Algae on Reed in the Shihwa Constructed Wetland (시화호 인공습지의 식물 플랑크톤과 갈대 부착조류 군집의 동태)

  • Kim, Yong-Jae;Kwun, Soon-Kuk
    • Korean Journal of Environmental Agriculture
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    • v.23 no.1
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    • pp.59-67
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    • 2004
  • The Shihwa constructed wetland was established for the treatment of severely polluted water from Banwoul, Donghwa and Samhwa streams. This study was focused on investigating dynamics of phytoplankton communities in open waters and periphytic algae on reed (Phragmites communis) planting area at 5 stations from October 2001 to July 2002. The concentration of T-N and T-P of inlet stations from the streams were decreased by flowed through the wetland. However, the TN/TP ratios at all stations were shown as a little over 16 indicating that the T-P will play some role as a limitation factor. Phytoplankton communities were identified as a total 413 taxa which were composed of 375 species, 21 varieties, 2 forma and 15 unidentified species. Standing crops of phytoplankton communities and chlorophyll-a concentrations ranged from $330{\sim}36,420\;cells/mL$ and $2.5{\sim}170.7\;{\mu}g/L$ respectively, and showed the decreasing tendency after flowing through the wetland at almost all stations. Dominant species were 14 taxa at all stations which were Euglena oblonga and Synura spinosa etc. Periphytic algae on the reed were a total 329 taxa which were composed of 295 species, 13 varieties, 3 forma and 17 unidentified species. The species numbers were recorded in order of Chlorophyceae-Bascillariophyceae-Cyanophyceae-Euglenophyceae-Chrysophyceae. The relative abundance (%) was showed a seasonal variation from Cyanophyceae to Bascillariophyceae and to Chlorophyceae. Chlorophyll-a concentrations, ie. the biomass of periphytic algae were ranged from $5.5{\sim}363.8\;mg/m^2$. Dominant species were 16 taxa which were Lyngbya angusta of Cyanophyceae in the early investigation, and were changed to Stigeoclonium lubricum of Chlorophyceae, and Nitzschia plea of Bacillariophyceae etc. in the late. Species number, standing crops and chlorophyll-a concentrations of phytoplankton and perphytic algae were shown higher values at the inlet stations than the stations after flowing through the wetland.

Analysis of Dietary Fiber Intake in the Korean Adult Population Using 2001 Korean National Health and Nutrition Survey Data and Newly Established Dietary Fiber Database (식이섬유 D/B 구축과 2001 국민건강 영양조사 식이섬유 섭취량 재평가 -20세 이상 성인을 대상으로-)

  • Yu, Kyung-Hye;Chung, Chin-Eun;Ly, Sun-Yung
    • Journal of Nutrition and Health
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    • v.41 no.1
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    • pp.100-110
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    • 2008
  • The present study estimates intake levels of dietary fiber (DF) in Korean adults aged 20 and over, using a newly established dietary fiber database for 3,149 food items, as well as 24-hour recall method data from the 2001 Korean National Health and Nutrition Survey. Dietary fiber intake and food groups are analyzed by gender, age, and region. The average dietary fiber intake, per capita of Korea was estimated to be 12.24g/1,000kcal or 23.58g/day. Calorie-based dietary fiber intake for 20-49 year-old-Korean males, 20-29 year-old females, and the adults who resided in metropolitan areas was under the Adequate Intake for DF, 12 g/1,000 kcal. Further, the dietary fiber intake after adjusting energy intake in people over 75 year-old was estimated to be 75% of AI. Vegetables, cereals and fruits were three major sources of DF for Korean, making up approximately 75% of DF. Regarding the subjects of this study, major sources of dietary fiber were Kimchi and well-polished rice, which supplied 13.98% and 9.16% of total dietary fiber intake, respectively. The result of this study could contribute to the establishment of DRIs for dietary fiber, after adjusting energy intake for Korean aged 75 years and over. The beneficial health effects of DF and the necessity of nutritional education in this area should be continuously emphasized concerning 20-29 year-old people and metropolitan adults.

Study on the Improvement of Gill Nets and Trap Nets Fishing for the Resource Management at the Coastal Area of Yellow Sea - On the Entrapping Behavior of Fishes into Trap Nets in the Water Tank Experiment - (서해구 자원관리형 자망ㆍ통발 어구어법 기술개발에 관한 연구 - 수조에서의 통발에 대한 어군의 입롱행동 -)

  • 장호영;조봉곤;고광수;한민숙
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.1
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    • pp.56-62
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    • 2003
  • To investigate the entrapping behavior of blue crab, rock shell and green ling, which are mainly caught with the other trap nets in the coastal area of Yellow Sea, by the using duration of trap nets through the water tank experiment. We select the three kinds of trap nets which have different using duration such as new, 6 months and 12 months used one, and observe the entrapping ratio into the trap nets, respectively. In the mean while, in order to obtain the basic data for the estimate of mesh selectivity of the other trap nets, the entrapping behavior into the trap nets for green ling which has high activity compared to blue crab and rock shell, are examined to the three kinds of mesh size (35mm, 50mm and 65mm). The results are as follows ; 1. The mean entrapping ratio of blue crab by the using duration of trap nets in high with 4.4 fishes (44.0%) in the 6 months used one, become lower with 2.9 fishes (28.0%) in the new one, and with 2.0 fishes (20.0%) in the 12 months used one. 2. The mean entrapping ratio of rock shell by the using duration of trap nets in high with 7.3 fishes (36.7%) in the new one, and become lower with 7.2 fishes (35.8%) in the 6 months used one, and with 5.7 fishes (28.3%) in the 12 months used one. 3. The mean entrapping ratio of green ling by the using duration of trap nets in high with 3.4 fishes (34.0%) in the 6 months used one, and become lower with 3.0 fishes (30.0%) in the new one, and with 2.8 fishes (28.0%) in the 12 months used one. 4. The mean residual ratio of green ling by the mesh size of trap nets is high with 2.4 fishes (24.0%) in the 35mm mesh size, and become lower with 2.2 fishes (22.0%) in the 50mm mesh size and 2.0 fishes (20.0%) in the 65mm mesh size.

Staphylococcal Scalded Skin Syndrome in Children : Comparison of the Clinical Features of That Isolated Methicillin-resistant and Methicillin-sensitive Staphylococcus aureus (포도상 구균성 열상 피부 증후군의 임상적 고찰 : Methicillin 내성과 감수성 Staphylococcus aureus 예의 비교)

  • Lee, Seong Hun;Choi, Wu Kyung;Jung, Chang Hyn;Chung, Cheol Ju;Lee, Dong Jean
    • Pediatric Infection and Vaccine
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    • v.11 no.2
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    • pp.183-191
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    • 2004
  • Purpose : The purpose of this study was to compare the clinical features of staphylococcal scalded skin syndrome(SSSS) isolated methicillin-resistant Staphylococcal aureus(MRSA) with those of SSSS isolated methicillin-sensitive Staphylococcal aureus(MSSA) in children. Methods : We retrospectively reviewed the medical records and microbiological results of 36 cases of SSSS who were admitted to the Pediatric Department of Ulsan Dong-Kang General Hospital from Jan. 1999 to Dec. 2003. Results : Among 36 cases, there were 7 generalized types, 1 abortive type in MRSA group and 5 generalized types, 6 abortive types in MSSA group. The peak incidence of age was between 2 and 5 years in both groups. SSSS were diagnosed with increasing frequency. Most of MRSA group were diagnosed in 2003(6/8). The peak seasonal incidence was fall and winter in both groups. Facial lesion was observed in all cases followed by flexural lesion in both groups. Staphylococci were isolated from the skin and throat most frequently in both groups. Upper respiratory illness and conjunctivitis were most common preceding infections in both groups. Among 8 cases of MRSA group, 4 cases were treated completely with ampicillin-sulbactam. There was no significant difference of mean duration of admission between MRSA group and MSSA group. Conclusion : There was no significant difference of clinical features between MRSA group and MSSA group although generalized types of SSSS were more common in MRSA group than in MSSA group.

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Effect of Nitrogen Application Level and Regrowth Period on Composition of Fatty Acid in Tall fescue and Bermudagrass (질소시비 수준 및 재생기간이 톨페스큐와 버뮤다그라스의 지방산조성에 미치는 영향)

  • Park, Hyung-Soo;Hwang, Kyung-Jun;Park, Nam-Gun;Kim, Young-Jun;Jeong, Ha-Yeon;Jo, Nam-Chul;Ko, Moon-Suck
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.29 no.1
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    • pp.43-50
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    • 2009
  • Two experiments were conducted to evaluate the effects of nitrogen (N) application level and regrowth period on the fatty acid (FA) concentration and forage production of tall fescue (Festuca arundinacea Schr.) and bermudagrass (Cynodon dactylon (L.) Pers.). N was applied at 0, 50 and 100 kg/ha, and swards were cut after regrowth periods (15d, 30d and 45d). Concentrations of Individual FA were determined by gas chromatography. FA composition of tall fescue contains a high proportion ($87{\sim}88%$) of total FA contents as palmitic (C16:0), linoleic (C18:2) and linolenic acid (C18:3). The FA composition was not affected by N application, but a longer regrowth period significantly (p<0.05) decreased the composition of linolenic acid (C18:3) and increased those of linoleic acid (C18:2). The FA composition of bermudagrass was not affected by N application, but a longer regrowth period significantly (p<0.001) decreased the composition of linoleic (C18:2) and linolenic acid (C18:3). Linoleic and linolenic acfd of tall fescue were higher than those of bermudagrass. Dry matter (DM) yield of bermudagrass was significantly (P<0.05) affected by N application level and regrowth period. DM yield was higher at high N application and was higher at longer regrowth period. The crude protein concentration was higher at high N application and was low at longer regrowth period. Application of nitrogen fertilizer Increases dry matter (DM) yield and crude protein (CP) content of bermudagrass. These studies demonstrate opportunities to affect the FA concentration and composition of FA in forage through management strategies, which could affect milk FA composition.

Surface Exchange of Energy and Carbon Dioxide between the Atmosphere and a Farmland in Haenam, Korea (한국 해남 농경지와 대기간의 에너지와 이산화탄소의 지표 교환)

  • Hee Choon Lee;Jinkyu Hong;Chun-Ho Cho;Byoung-Cheol Choi;Sung-Nam Oh;Joon Kim
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.5 no.2
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    • pp.61-69
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    • 2003
  • Surface energy and $CO_2$ fluxes have been measured over a farmland in Haenam, Korea since July 2002. Eddy covariance technique, which is the only direct flux measurement method, was employed to quantitatively understand the interaction between the farmland ecosystem and the atmospheric boundary layer. Maintenance of eddy covariance system was the main concern during the early stage of measurement to minimize gaps and uncertainties in the dataset. Half-hourly averaged $CO_2$ concentration showed distinct diurnal and seasonal variations, which were closely related to changes in net ecosystem exchange (NEE) of $CO_2$. Daytime maximum $CO_2$ uptake was about -1.0 mg $CO_2$ m$^{-2}$ s$^{-1}$ in August whereas nighttime $CO_2$ release was up to 0.3 mg $CO_2$ m$^{-2}$ s$^{-1}$ during the summer. Both daytime $CO_2$ uptake and nighttime release decreased gradually with season. During the winter season, NEE was from near zero to 0.05 mg $CO_2$ m$^{-2}$ s$^{-1}$ . FK site was a moderate sink of atmospheric $CO_2$ until September with daily NEE of 22 g $CO_2$ m$^{-2}$ d$^{-1}$ . In October, it became a weak source of $CO_2$ with an emission rate of 2 g $CO_2$ m$^{-2}$ d$^{-1}$ . Long-term flux measurements will continue at FK site to further investigate inter-annual variability in NEE. to better understand these exchange mechanism and in-depth analysis, process-level field experiments and intensive short-term intercomparisons are also expected to be followed.

The Grazing Rates and Community Dynamics of Zooplankton in the Continuous River Stretch Ecosystem Include with Brackish Zone (기수 지역을 포함한 연속적인 강 구획 생태계 내에서의 동물플랑크톤의 군집 동태와 섭식율)

  • Kim, Hyun-Woo
    • Korean Journal of Ecology and Environment
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    • v.39 no.4 s.118
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    • pp.462-470
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    • 2006
  • The zooplankton community dynamics and grazing experiments was evaluated along a 40 km section of the lower Seomjin river system. Zooplankton was sampled twice a month from January 2005 to June 2006 at three sites (River mouth; RKO, Seomjin bridge: RK12 and Gurae bridge: RK36) in the main river channel. During the study period, the values of most limnological parameters in the three sites were fairly similar, except for conductivity. Annual variation of conductivity in River mouth and Seomjin bridge was more dramatic than which of the other site. There were statistically significant spatial and seasonal differences in zooplankton abundance (ANOVA, P<0.01). Total abundance of major zooplankton groups at both stations was much higher than in Gurae bridge. Among the macrozooplankton, cladocerans abundance was negligible in study sites during study periods. Community filtering rates (CFRs) for phytoplankton and bacteria varied from 0 to 50 mL $L^{-1}\;D^{-1}$ and from 0 to 45 mL $L^{-1}\;D^{-1}$, respectively. The spatial variation of CFRs for phytoplankton was significant (ANOVA, P<0.05). The CFRs of copepods for phytoplankton and bacteria was much higher than that of cladocerans at study sites. Total zooplankton filtering rates on bacteria were slightly lower than filtering rates on phytoplankton. The CFRs of microzooplankton (MICZ) for bacteria were much higher than for macrozooplankton (MACZ) at all sites. Considering the total zooplankton community, MICZ generally were more important than MACZ as grazers of bacteria and phytoplankton in freshwater zone, while MACZ were more important than MICZ as grazers of phytoplankton in brackish zone.