• 제목/요약/키워드: precipitation patterns

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A Study on the Corelation between the Variation of Land Cover and Groundwater Recharge Using the Analysis of Landsat-8 OLI Data (Landsat-8 위성을 통한 토지피복 변화와 지하수 함양량 상관성 고찰)

  • Park, Seunghyuk;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.30 no.3
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    • pp.347-378
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    • 2020
  • Based on monthly average groundwater recharge over a nearly 10 year period, results of fully integrated hydrologic modeling of SWAT-MODFLOW, land cover, land use, soil type and hydrologic response unit (HRU) was used to assess the dominant influencing factors of groundwater recharge spatial patterns in Jangseong district. As dominant factors, land cover was FRSE (forest-evergreen) and soil type was Samgag. Landsat-8 OLI imaging spectrometer data were acquired in the period 2003 to 2004 and seasonal bare soil lines (BSL) were estimated through NIR-RED plot. Extent of slope of BSL was from 1.092 to 1.343 and the intercept was from -0.004 to -0.015. To know correlation between spatial groundwater recharge and soil-vegetation indices (PVI, NDVI, NDTI, NDRI), this study employed frequency and regression analysis. On May, RED band increased up 3 to 4 times compared to other seasons and only one turning point appeared as recharge-index with upward parabola bell shape as results of existing research. Considering precipitation, if the various studies for relationship between groundwater recharge and soil-vegetation index just like NDVI are performed, it is possible to estimate groundwater recharge through analyzing remote sensing data.

Microstructure and Morphology of Carbide Precipitates in $Ni_3Al$ and TiAl ($Ni_3Al$과 TiAl 중에 석출한 탄화물의 미세구조와 형태)

  • Han, Chang-Suk;Koo, Kyung-Wan;Kim, Jang-Woo
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.1
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    • pp.10-19
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    • 2006
  • Microstructure and morphology of precipitates in $Ni_3Al$- and TiAl-based intermetallics containing carbon have been investigated in terms of transmission electron microscopy(TEM). In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide were formed in the matrix by aging at temperatures around 973 K after solution annealing at 1423 K. TEM examination revealed that the $M_{23}C_6$ phase and the matrix lattices have a cube-cube orientation relationship and keep partial atomic matching at the {111} interface. After prolonged aging or by aging at higher temperatures, the $M_{23}C_6$ precipitates then adopt a rod-like morphology elongated parallel to the <100> directions. In the $L1_0$-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction(SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $Ti_2AlC$ and the $L1_0$ matrix is $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ and $_{Ti2AlC}//_{L10\;matrix}$.

Conversion of Ginseng Saponin with the Enzyme Produced by Rhizopus sp. (Part 1) Confirmation of Conversion of Ginsenoside- Rb$_1$to Ginsenoside-Rd (Rhizopus sp.가 생산하는 효소에 의한 인삼 Saponin의 전환 (제1보) Ginsenoside-Rb$_1$에서 Ginsenoside-Rd로의 전환확인)

  • 김상달;서정훈
    • Microbiology and Biotechnology Letters
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    • v.10 no.4
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    • pp.267-273
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    • 1982
  • Among 12 kinds of ginsenosides in ginseng saponin, ginsenoside-Rb$_1$was contained the most abundantly. But ginsenoside-Rd which is similar to ginsenoside-Rb$_1$in structure, was known to be superior to ginsenoside-Rb$_1$pharmaceutically. In order to convert ginsenoside-Rb$_1$into ginsenoside-Rd by microbial enzyme treatment, a Rhizopus sp. was selected among various strais of molds found in rotten ginseng roots. Enzyme was prepared from the extract of wheat bran koji culture by ammonium sulfate precipitation (1.0 sat'd) and succeeding ammonium sulfate fractionation method (0.6-0.9 sat'd). For the purpose of use as substrate, saponins were purified by the several purification steps from alcohol extract of red ginseng roots. We obtained the total saponin which was composed of 36.5% of ginsenoside Rb$_1$, 12.2% of ginsenoside-Rd and other ginsenosides. For increase of ginsenoside-Rb$_1$ component ratio, we also obtained further purified ginsenoside-Rb group saponin containing 54.5% of ginsenoside-Rb$_1$, 1.1% of ginsenoside- Rd and other ginsenosides from purified the total saponin. In the enzymatic reaction system including the total saponin or the ginsenoside-Rb group saponin, we confirmed the specific conversion of ginsenoside-Rb$_1$to ginsenoside-Rd proportionally and no change of any other ginsenoside patterns by thin layer chromatography and high performance liquid chromatography.

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Estimation of Land Surface Energy Fluxes using CLM and VIC model (CLM과 VIC 모형을 활용한 지표 에너지 플럭스 산정)

  • Kim, Daeun;Ray, Ram L.;King, Seokkoo;Choi, Minha
    • Journal of Wetlands Research
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    • v.18 no.2
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    • pp.166-172
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    • 2016
  • Accurate understanding of land surface is essential to analyze energy exchanges between earth surface and atmosphere. For the quantization of energy fluxes, the various researches about Land Surface Model(LSM) have been progressed. Among the various LSMs, the researches using Common Land Model(CLM) and Variable Infiltration Capacity(VIC) model are performed briskly. The CLM which is advanced LSM can calculate realistic results with few user defined parameters. The VIC model which is also typical LSM is widely used for estimation of energy fluxes and runoff in various fields. In this study, the energy fluxes which are net radiation, sensible heat flux, and latent heat flux were estimated using CLM and VIC model at Southern Sierra-Critical Zone Observatory(SS-CZO) site in California, United States. In case of net radiation and sensible heat flux, both models showed good agreement with observations, however, the CLM showed underestimated patterns of net radiation and sensible heat flux during precipitation period. In case of latent heat flux, the CLM represented better estimation of latent heat flux than VIC model which underestimated the latent heat flux. Through the estimation of energy fluxes and analysis of models' pros and cons, the applicability of CLM and VIC models and need of multi-model application were identified.

Georeferencing of Primary Species Occurrence Data and Necessity of Data Quality Control - A Case Study of Two Varieties of Ox-Knee, Achyranthes bidentata Blume - (1차종발생자료를 응용한 지리참조연산표준화 및 자료 품질 관리의 필요성 - 쇠무릎과 털쇠무릎의 적용 사례 -)

  • Chang, Chin-Sung;Chang, Kae Sun;Ahn, Yong-Sup;Kim, Hui
    • Journal of Korean Society of Forest Science
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    • v.101 no.2
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    • pp.185-194
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    • 2012
  • The purpose of this contribution is to develop the framework of a methodology for identifying potential errors in georeferencing and in an application of it using specimens of Ox-Knee, Achyranthes bidentata Blume in Korea. At infraspecific level, uncertainty of identification showed that 41% of A. bidentata var. japonica and 28% of var. bidentata were misidentified, suggesting that the uncertainty level was independent of the reliability of experts' identification. For georeference specimen records, 71 specimens out of total 303 were selected and utilized as occurrence data: Uncertainty was 32.4 km at maximum and was 0.1297 km at minimum (mean = 4,055 m, s.d. = 5,772 m). Var. japonica is common throughout most of the southeastern Korea and west coastal areas, while var. bidentata has been found as far north as Gyeonggi and Gangwon provinces. We modelled the potential distribution of two varieties using Bioclim approach in Korea based on several environmental factors. Our results indicated the most important region for var. japonica lies the west coast ranges and southern area, while for Chungcheongnam-do of potential high diversity occurs for var. bidentata. This study shows that the major factors to determine the distribution patterns of two varieties were thermal factors, rather than precipitation. The Bioclim model using geocode and georeferencing data makes the information increasingly useful and reliable. To improve data quality, it requires full management from data collection to final databases including data cleaning.

Analysis of MODIS LAI and NDVI Patterns of Broad-leaved Trees by the Timesat Program on the Korean Peninsula (Timesat 프로그램에 의한 한반도 활엽수의 지역별 MODIS LAI 및 NDVI 패턴 분석)

  • Seo, Dae Kyo;Lee, Jeong Min;Lim, Ye Seul;Han, Sang Won;Pyeon, Mu Wook
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.2
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    • pp.13-19
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    • 2017
  • This paper analyzed MODIS data from 2006 to 2013 to determine relationship between meteorological changes and vegetation index. The experimental area was divided into the northern, central and southern regions according to the regional characteristics, and the smoothed MODIS LAI and NDVI were obtained using Timesat. In the case of precipitation, MODIS NDVI had correlation coefficients of 0.66, 0.44 and 0.35 in the northern, central and southern regions and the correlation was the highest in the northern region. In the case of temperature, MODIS LAI had correlation coefficients of 0.66, 0.64 and 0.68, and MODIS NDVI had 0.89, 0.89 and 0.80. The correlation of MODIS NDVI was higher and showed similar positive correlation regardless of region. In addition, The accuracy between Timesat plant seasonal start and actual plant seasonal start in MODIS NDVI was higher than MODIS LAI. The average error in MODIS LAI was 19 days in the central region and 20 days in the southern region. And the average error in MODIS NDVI was 6 days in the central region and 8 days in the southern region.

A Study ‘On the Morbid Pulse of Abdominal Fullness, Cold Mounting, and Abiding Food' in the Chapter 10 of Synopsis of Golden Chamber (금궤요약(金匱要略).복만한산숙식병맥증병치제십(腹滿寒疝宿食病服證幷治第十)에 대(對)한 연구(硏究))

  • Seo, Dae-Seon;Ahn, Jun-Mo;Cho, Gyeong-Jong;Jeong, Heon-Young
    • Journal of Korean Medical classics
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    • v.19 no.2 s.33
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    • pp.138-162
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    • 2006
  • 'On the Morbid Pulse of Abdominal Fullness, Cold Mounting, and Abiding Food' in the Chapter 10 of Synopsis of Golden Chamber that enunciates Abdominal Fullness, Cold Mounting, and Abiding Food is related to the stomach and intestines respectively, and is similar to the region and symptom of disease in the light of both abdominal fullness and symptoms of pain. This chapter was united into one because the formula mentioned in this chapter can be applied to three disease patterns. Abdominal fullness shows the symptoms of distention and unease, but judging from the text as well as a specific formula and symptoms, it follows pain. Accordingly Abdominal fullness dealt with in this chapter is the first consideration and it is a kind of a disease pattern attendant on abdominal pain. Cold Mounting does not mean mounting gi disease but means the abdominal pain. The cause of cold mounting is mainly due to insufficiency of yang gi and oversufficiency of cold evil. And the main symptoms of cold mounting follow the severe pain around the naval and sweating, cold of the extremities, pulse deep and tight. Abiding food is of the same meaning such as damage of food today. Abiding food is now referred to as damage of food. Principles which have set forth in this chapter are put to use of the method of ejection in case that abiding food places in the upper part, precipitation in the lower part. The symptoms of abiding food show that the pulse is slight and slippery and the wrist pulse is both superficial and large and rough in applying the pressure, and the cubit pulse is also slight and superficial as well, and that have diarrhea and have little appetite.

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Change of Ion Concentrations in Soil Solution According to Different Cutting Intensities and Sampling Times in Pinus rigida Plantations (리기다소나무조림지(造林地)의 벌채수준(伐採水準) 및 시료(試料) 채취시기(採取時期)에 따른 토양수내(土壤水內) 이온농도(濃度) 변화(變化))

  • Oh, Kwang-In;Cho, Hi-Doo;An, Ki-Wan;Kim, Choonsig
    • Journal of Korean Society of Forest Science
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    • v.88 no.4
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    • pp.438-445
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    • 1999
  • The concentrations of some ions ($NO{_3}^-$, $Ca^{2+}$, $Mg^{2+}$, $NH{_4}^+$) in soil solution collected by zero tension lysimeter in mature Pinus rigida plantations in Goksung, Jeonranam-do were measured at two soil depths (10cm and 30cm) following various levels of cutting intensity treatment (uncut, $6m{\times}50m$, $10m{\times}50m$, $20m{\times}50m$ strip crearcutting) three times (July 6. July 30, and August 4) between June 20 and August 4 1998. The ion concentrations in the soil solution were significantly different among sampling times, while the concentrations were not different among cutting levels or sampling depths. The ion concentrations in the soil solution decreased in the order of $NO{_3}^-$ > $Ca^{2+}$ > $Mg^{2+}$ > $NH{_4}^+$ and the mean concentration was 3.60mg/L for $NO{_3}^-$, 1.7mg/L for $Ca^{2+}$, 0.5mg/L for $Mg^{2+}$, and 0.04mg/L for $NH{_4}^+$ respectively. These ion concentrations except for $NH{_4}^+$ ion were negatively correlated with the volume of collected soil solutions (r=-0.31~-0.41). The results suggest that the change of nutrient concentrations in the soil solution collected from the P. rigida plantations was related to the temporal input patterns of precipitation rather than the cutting intensity.

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Synthesis and Electrochemical Performance of Mesoporous Hollow Sphere Shape LiMn2O4 using Silica Template (실리카 템플레이트를 이용하여 다공성 중공형태를 갖는 LiMn2O4 합성 및 전기화학적 특성 연구)

  • Ryu, Seong-Hyeon;Ryu, Kwang-Sun
    • Journal of the Korean Electrochemical Society
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    • v.14 no.3
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    • pp.184-190
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    • 2011
  • $LiMn_2O_4$ with mesoporous hollow sphere shape was synthesized by precipitation method with silica template. The synthesized $LiMn_2O_4$ has nanosized first particle and mesoporous hollow sphere shape. Silica template was removed by chemical etching method using NaOH solution. When the concentration of NaOH solution was increased, first particle size of manganese oxide was decrease and confirmed mesoporous hollow shpere shape. X-ray diffraction(XRD) patterns revealed that the synthesized samples has spinel structure with Fd3m space group. In case the ratio of silica and maganese salt increased, the size of first particles was decreased. The tetragoanal $LiMn_2O_4$ with micron size was synthesized at ratio of silica and manganese salt over 1 : 9. The prepared samples were assembled as cathode materials of Li-ion battery with 2032 type coin cell and their electrochemical properties are examined by charge-discharge and cyclic performance. Electrochemical measurements show that the nano-size particles had lower capacity than micron-size particles. But, cyclic performance of nano-size particles had better than that of micron-size particles.

Quantification of Environmental Characteristics on Citrus Production Area of Jeju Island in Korea (제주도 감귤 재배지역에 대한 환경특성의 정량화)

  • Moon, Kyung Hwan;Son, In-Chang;Song, Eun Young;Oh, SoonJa;Park, Kyo Sun;Hyun, Hae-Nam
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.1
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    • pp.69-74
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    • 2015
  • To analyze quantitatively environmental characteristics of cultivation area of citrus, Satsuma mandarin (Citrus unshiu Marc.), we made digital maps of environmental elements such as topography and climate. Elevation, degree of slope, and slope aspect were selected as elements of topological environment, and the annual mean air temperature, annual total precipitation, mean air temperature on January, extreme value of daily minimum air temperature, and the number of days below $-5^{\circ}C$ were selected as elements of climatic environments. The grid values of 8 environmental elements were extracted by shape of citrus farm area and analyzed distribution patterns. We can determine 3 agroclimatic criteria for growing Satsuma mandarin as over $14.5^{\circ}C$ of annual mean air temperature, over $-10.0^{\circ}C$ of extreme value of daily minimum air temperature, and less 5 days of below $-5^{\circ}C$ of daily minimum air temperature.