• Title/Summary/Keyword: GR4J

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Effective Weed Control in Direct-Seeded Rice under Dry Fields (벼 건답직파(乾畓直播)에 있어서 효과적(效果的)인 잡초방제(雜草防除))

  • Park, T.S.;Park, J.E.;Ryu, G.H.;Lee, I.Y.;Lee, H.K.;Lee, J.O.
    • Korean Journal of Weed Science
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    • v.15 no.2
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    • pp.99-104
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    • 1995
  • This experiment was conducted to evaluate effective weed control in direct-seeded rice under dry fields. The results obtained are as follows. Cyhalofop/bentazone EW and cyhalofop/pendimethalin EC were very effective for the weed control but cyhalofop/cinosulfuron WP and cyhalofop/azimsulfuron SC were tended to exhibit the lower weeding effect. The plant height and the tiller number of rice were not greatly affected by herbicides, but rice yield was greatly influenced by them. The control efficacy was observed the extend of 94% until 60days after seeding under the treatment of systematic herbicides such as foliar applied pendimethalin propanil EC at 15days after seeding mowed by pyrazosulfuron molinate GR at 5days after irrigation. Irrigation at 25days after seeding was able to control annual weeds by the extent of 25% and exhibited control effect of 94% on systematic treatment of herbicides compared with that of 35days after seeding.

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Climate change impact analysis on water supply reliability and flood risk using combined rainfall-runoff and reservoir operation modeling: Hapcheon-Dam catchment case (강우-유출 및 저수지 운영 연계 모의를 통한 기후변화의 이수안전도 및 홍수위험도 영향 분석: 합천댐 유역 사례)

  • Noh, Seong Jin;Lee, Garim;Kim, Bomi;Jo, Jihyeon;Woo, Dong Kook
    • Journal of Korea Water Resources Association
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    • v.56 no.11
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    • pp.765-774
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    • 2023
  • Due to climatechange, precipitation variability has increased, leading to more frequentoccurrences of droughts and floods. To establish measures for managing waterresources in response to the increasing uncertainties of climate conditions, itis necessary to understand the variability of natural river discharge and theimpact of reservoir operation modeling considering dam inflow and artificialwater supply. In this study, an integrated rainfall-runoff and reservoiroperation modeling was applied to analyze the water supply reliability andflood risk for a multipurpose dam catchment under climate change conditions. Therainfall-runoff model employed was the modèle du Génie Rural à 4 paramètresJournalier (GR4J) model, and the reservoir operation model used was an R-basedmodel with the structure of HEC-Ressim. Applying the climate change scenariosuntil 2100 to the established integrated model, the changes in water supplyreliability and flood risk of the Happcheon Dam were quantitatively analyzed.The results of the water supply reliability analysis showed that under SSP2-4.5conditions, the water supply reliability was higher than that under SSP5-8.5conditions. Particularly, in the far-future period, the range of flood risk widened,and both SSP2-4.5 and SSP5-8.5 scenarios showed the highest median flood riskvalues. While precipitation and runoff were expected to increase by less than10%, dam-released flood discharge was projected to surge by over 120% comparedto the baseline

Natural Convection in a Rectangular Enclosure with Heat Sources at the Bottom (밑면에 열원이 존재하는 밀폐공간에서의 자연대류)

  • Kwon, Y.I.;Kim, S.J.;Kwon, S.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.3 no.3
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    • pp.197-205
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    • 1991
  • A numerical study has been performed to investigate two dimensional natural convection heat transfer in a rectangular enclosure with heat sources of constant temperature at the bottom. Calculations were made for various dimensionless heat source lengths, W/L=0.1-0.5, and positions of heat sources at $Gr=2.57{\times}10^6$, Pr=0.71 and Ks/Kf=28.98. For various positions of heat sources, the maximum local Nusselt numbers generally show X=0.81-0.85 at the bottom and X=0.23 at the top. For various dimensionless heat source lengths, the maximum local Nusselt numbers at the bottom show W/L=0.4 for one heat source, W/L=0.2 for two heat sources with fixed centers, W/L=0.5 for two heat sources with moved centers. Finally the maximum heat transfer at the bottom exhibits in condition of W/L=0.4 for two heat sources with moved centers.

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Seed Storage Method and Seed Germination Characteristics of Synurus deltoides(Ait.) Nakai (수리취의 종자저장 방법과 발아특성)

  • Noh, H.S.;Kwon, H.K.;Sung, J.W.;Shim, Y.J.;Lee, K.C.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.24 no.1
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    • pp.29-35
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    • 2022
  • This study was conducted to investigate the seed storage method and seed germination characteristics of Synurus deltoides (Ait.) Nakai, a kind of wild vegetables. Several parameters affecting seed germination, such as germination temperature, chilling duration, imbibition duration, and storage method were evaluated. The seed germination of Synurus deltoides showed the highest germination rate (GR), promptness index (PI), germination performance index (GPI), mean daily germination (MDG) at 25℃. This implies that the optimum germination temperature was 25℃. And also, Seeds stored at -4℃, after 150 days showed relatively high germination rate about 98%. Therefore, The optimum germination temperature of Synurus deltoides was 25℃ and to increase the germination rate over 98% of Synurus deltoides, cold-wet storage 20 days treatments at 4℃ were effective in the improvement of seed germination.

Effects of Gwanjul8-bang on Collagen Induced Arthritis in DBA/1J Mice (관절8호방이 Collagen 유발 관절염에서 DBA/1J 생쥐에 미치는 영향)

  • Kim, Jong-Kook;Oh, Min-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.2
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    • pp.17-34
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    • 2010
  • Objectives : This study was carried out to know the effects of Gwanjul8-bang(here in after reffered to GJ8) on the inhibition of arthritis induced by collagen on DBA/1J mice. Methods : For this purpose, GJ8 was orally administered to mouse with arthritis induced by collagen II. Cytotoxicity, hepatotoxicity, arthritis index, value of immunocyte in draining lymph node(DLN) and paw joint, cytokine in serum were measured in vivo. Results : 1. The arthritis index was decreased significantly. 2. In total cell counts of DLN and paw joint, the cells in DLN increased significantly while there was a significant decrease in paw joint. 3. In lymph nodes, $CD19^+$, $CD3^+$, $CD4^+/CD25^+$ cells increased significantly, and $B220^+/CD23^+$ cells decreased significantly. 4. In joints, $CD3^+$, $CD4^+$, $CD11b^+/Gr-1^+$ cells decreased significantly. 5. The levels of $TNF-{\alpha}$, IL-6, IL-17, MCP-1 and vascular endothelial growth factor(VEGF) in serum was significantly decreased compared with control. 6. Anti-collagen II in serum was significantly decreased compared with control. 7. The degree of arthritis induced damage of joint of GJ8 group is slight compared with control group in histopathologic observation(hematoxylin & eosin(H&E), Masson-Trichrome(MT) staining). Conclusions : Comparison of the results for this study showed that GJ8 had immunomodulatory effects. So we expect that GJ8 should be used as a effective drugs for not only rheumatoid arthritis but also another auto-immune disease. Therefore there seems to be many clinical research needed in the future.

Inhibitory Effects of Gwanjul9-bang on Collagen Induced Arthritis in DBA/1J Mouse (관절9호방이 생쥐의 Collagen II 유발 관절염에 미치는 영향)

  • Kim, Eun-Hye;Oh, Min-Seok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.3
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    • pp.490-503
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    • 2010
  • This study was carried out to know the effects of Gwanjul9-bang (hereinafter reffered to GJ9) on the inhibition of arthritis induced by collagen on DBA/1J mouse. For this purpose, GJ9 was orally administered to mouse with arthritis induced by collagen II. Cytotoxicity, hepatotoxicity, arthritis index, value of immunocyte in draining lymph node and paw joint, rheumatoid factor (IgG, IgM) in serum were measured in vivo. The cytotoxicity against hFCs was not measured in any concentration. The hepatotoxicity was low in GJ9 treated group compared with MTX group. The arthritis index was decreased significantly. In total cell counts of DLN and paw joint, the cells in DLN increased significantly while there was significantly decrease in paw joint. In lymph nodes, $CD19^+$, $CD3^+$, $CD4^+$, $CD3^+CD69^+$, $CD8^+$, $CD4^+CD25^+$, $CD3^+CD49b^+$, $CD4^+CD44^+$, $CD3^+CD8^+$ cells increased significantly, $B220^+CD23^+$cells decreased significantly. In joints, $CD3^+$, $CD4^+$, $CD4^+CD25^+$, $CD11b^+Gr-1^+$ cells decreased significantly. The levels of IgG and IgM was significantly decreased compared with control. Anti-collagen II in serum was significantly decreased compared with control. The degree of arthritis induced damage of joint of GJ9 group is slight compared with control group in histopathologic observation (Hematoxylin & Eosin, Masson's Trichrome). Comparison of the results for this study showed that GJ9 had immunomodulatory effects. So we expect that GJ9 should be used as a effective drugs for not only rheumatoid arthritis but also another auto-immune disease. Therefore we have to survey continuously in looking for the effective substance and mechanism in the future.

Effects of Planting Date on Agronomic Characteristics and Varietal Differences in Sesame Varieties (파종기 이동에 따른 참깨 품종들의 유용형질 변화 및 품종간 차이)

  • Lee, J.I.;Lee, S.T.;Um, G.C.;Park, C.H.
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.27 no.3
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    • pp.268-275
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    • 1982
  • This study was conducted to obtain basic informations for breeding and improving cultural practices of sesame (Sesamum indicum L.) through investigation of several agronomic characters of 82 major varieties plants in April 20, May 15 and June 20. Stem diameter and plant height were largest in early planting(April 20). On the contrary, they were smallest in late planting(June 15). Therefore, the later planting, the poorer the vegetative growth on the basis of stem diameter and plant height. Number of capsules per plant and number of grains per capsule were 88 and 54, respectively, in the early planting, while they were decreased to 25 capsules and 40 grains in late planting. The percentage of ripeness and 1000 grain weight 78 and 2.3g in the April 20planting while they were 58% and 2.1g in June 20 planting indicating the later planting, the lower the ripeness. Grain yield per m1 in April 20 and June 20 planting was 112 and 18g respectively. Consequently, grain yield significantly decreased as planting delayed. On the basis of the vegetative and reproductive growth, varieties could be classified into early, conventional, late and indetermediate planting adapted groups. The major yield components were highly and postively correlated with accmulated sunshine hours and temperatures confirming that grain yield was closely related with sunshine and temperature. Among the varieties tested, Gurye and Local 135 had more than 150 capsules. Haenam and Woogang had more than 75 grains per capsule. Since grain yield oflate planted sesame were significantly different among the varieties, breeding of sesame for after barly cropping would be more effective under late cultural condition of after barly.

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Mixed Convection Heat Transfer from Vertical In-Line Plates (수직 배열된 평판에서 혼합대류 열전달)

  • Kim, S.Y.;Ree, J.S.;Kwon, S.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.3 no.2
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    • pp.123-130
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    • 1991
  • The mixed convection heat transfer from vertical inline plates has been studied numerically by the finite difference method and experimentally with Mach-Zehnder interferometer. The dimensionless spacing, $s/L_1$, the relative length, $L_2/L_1$ and the dimensionless temperature ratio, ${\Phi}_2/{\Phi}_1$ are varied parametically. The lower plate mean Nusselt numbers show same values as $s/L_1$, ${\Phi}_2/{\Phi}_1$ and $L_2/L_1$ increase. The upper plate mean Nusselt numbers increase as $s/L_1$ and ${\Phi}_2/{\Phi}_1$ increase, but $L_2/L_1$ decreases. The upper plate mean Nusselt number is higher than the lower plate mean Nusselt for $s/L_1$ 1.8 at Re=100, $Gr=10^4$, Pr=0.71, $L_2/L_1=0.5$ and ${\Phi}_2/{\Phi}_1=1.0$. A comparison between the experimental and numerical results show good agreement.

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Seasonal effect on hydrological models parameters and performance

  • Birhanu, Dereje;Kim, Hyeonjun;Jang, Cheolhee;Park, Sanghyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.326-326
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    • 2018
  • The study will assess the seasonal effect of hydrological models on performance and parameters for streamflow simulation. TPHM, GR4J, CAT, and TANK-SM hydrological models will be applied for simulating streamflow in ten small and large watersheds located in South Korea. The readily available hydrometeorological data will be applied as an input to the four hydrological models and the potential evapotranspiration will be computed using the Penman-Monteith equation. The SCE-UA algorithm implemented in PEST will be used to calibrate the models considering similar objective functions bedside the calibration will be renewed to capture the seasonal effects on the model performance and parameters. The seasonal effects on the model performance and parameters will be presented after assessing the four hydrologic models results. The conventional approach and season-based results will be evaluated for each model in the tested watersheds and a conclusion will be made based on the finding of the results.

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On the Study of the Natural Convection in the Fluid near a Vertical Cylinder Heated with Uniform Heat Flux (일정 열유속으로 가열되는 수직원통 주위의 유체에서의 자연대류에 관한 연구)

  • Lee, C.J.;Kim, S.P.
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.17 no.4
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    • pp.426-434
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    • 1988
  • Series expansion is applied to solve the laminar boundary layer equations for the problem of natural convection from vertical cylinder with uniform surface heat flux. The series in terms of transverse curvature parameter ${\xi}$ is extended to five terms and is well converged by applying the Shanks transform twice. In case of natural convection from a vertical cylinder heated with uniform surface heat flux, it is possible to consider the vertical cylinder as vertical plate under the condition of D/L${\geq}$A/$(Gr_L^*)^{1/5}$, where A is in the range of 5.7~55.2. Also, mean Nusselt number ${\overline{Nu_L}}$ can be represented as $C_1(Ra_L^*)^{1/5}$, where $C_1$ is a constant which depends on Pr and is in the range of 0.5~0.8.

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