• 제목/요약/키워드: L-curve

검색결과 1,404건 처리시간 0.031초

A Study of Soil Moisture Retention Relation using Weather Radar Image Data

  • Choi, Jeongho;Han, Myoungsun;Lim, Sanghun;Kim, Donggu;Jang, Bong-joo
    • Journal of Multimedia Information System
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    • 제5권4호
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    • pp.235-244
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    • 2018
  • Potential maximum soil moisture retention (S) is a dominant parameter in the Soil Conservation Service (SCS; now called the USDA Natural Resources Conservation Service (NRCS)) runoff Curve Number (CN) method commonly used in hydrologic modeling for event-based flood forecasting (SCS, 1985). Physically, S represents the depth [L] soil could store water through infiltration. The depth of soil moisture retention will vary depending on infiltration from previous rainfall events; an adjustment is usually made using a factor for Antecedent Moisture Conditions (AMCs). Application of the method for continuous simulation of multiple storms has typically involved updating the AMC and S. However, these studies have focused on a time step where S is allowed to vary at daily or longer time scales. While useful for hydrologic events that span multiple days, this temporal resolution is too coarse for short-term applications such as flash flood events. In this study, an approach for deriving a time-variable potential maximum soil moisture retention curve (S-curve) at hourly time-scales is presented. The methodology is applied to the Napa River basin, California. Rainfall events from 2011 to 2012 are used for estimating the event-based S. As a result, we derive an S-curve which is classified into three sections depending on the recovery rate of S for soil moisture conditions ranging from 1) dry, 2) transitional from dry to wet, and 3) wet. The first section is described as gradually increasing recovering S (0.97 mm/hr or 23.28 mm/day), the second section is described as steeply recovering S (2.11 mm/hr or 50.64 mm/day) and the third section is described as gradually decreasing recovery (0.34 mm/hr or 8.16 mm/day). Using the S-curve, we can estimate the hourly change of soil moisture content according to the time duration after rainfall cessation, which is then used to estimate direct runoff for a continuous simulation for flood forecasting.

버어리종 담배중 암모니아성 질소에 대한 불확도 측정 (Uncertainty Evaluation of Ammonia Determination in Burley Tobacco)

  • 이정민;이경구;한상빈
    • 한국연초학회지
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    • 제27권1호
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    • pp.107-114
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    • 2005
  • The uncertainty of measurement in quantitative analysis of ammonia by continuous-flow analysis method was evaluated following internationally accepted guidelines. The sources of uncertainty associated with the analysis of ammonia were the weighing of sample, the preparation of extracting solution, the addition of extracting solution into the sample, the reproducibility of analysis and the determination of water content in tobacco, etc. In calculating uncertainties, Type A of uncertainty was evaluated by the statistical analysis of a series of observation, and Type B by the information based on supplier's catalogue and/or certificated of calibration. It was shown that the main source of uncertainty was caused by the volume measurement of 1 mL and 2 mL, the purity of ammonia reference material in the preparation of standard solution, the reproducibility of analysis and the determination of water content of tobacco. The uncertainty in the addition of extraction solution, the sample weighing, the volume measurement of 50 mL and 100 mL, and the calibration curve of standard solution contributed relatively little to the overall uncertainty. The expanded uncertainty of ammonia determination in burley tobacco at $95\%$ level of confidence was $0.00997\%$.

H-UV 무습수 오프셋 인쇄에서 CMS 적용에 관한 연구 (Study on CMS Application in Hybrid UV Waterless Off-Set Printing)

  • 구철회;조가람
    • 펄프종이기술
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    • 제45권5호
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    • pp.1-13
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    • 2013
  • This study found fit optimum C, M, Y, K solid density and $CIEL^*a^*b^*$ value to paper & ink as well as check about printing machine state for color management in H-UV waterless off-set printing first. These values applied to GRACoL G7 calibration method. This method is one of color standard management method of printing. GRACoL G7 calibration method is possible stable tone reappearance by controlling gray balance by NPDC(Natural Printing Density Curve). Also, this study used values to make device profile as result that is gotten by application of GRACoL G7 calibration method. This profile was applied to CMS(Color Management System) of H-UV waterless off-set printing, and the result was possible by color management that correspond in printing quality standard of ISO 12647-2 and GRACol 2006 specifications.

확산화염의 진동불안성의 기원에 대해서 (On the Origin of Oscillatory Instabilities in Diffusion Flames)

  • 김종수
    • 한국연소학회지
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    • 제10권3호
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    • pp.25-33
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    • 2005
  • Fast-time instability is investigated for diffusion flames with Lewis numbers greater than unity by employing the numerical technique called the Evans function method. Since the time and length scales are those of the inner reactive-diffusive layer, the problem is equivalent to the instability problem for the $Li\tilde{n}\acute{a}n#s$ diffusion flame regime. The instability is primarily oscillatory, as seen from complex solution branches and can emerge prior to reaching the upper turning point of the S-curve, known as the $Li\tilde{n}\acute{a}n#s$ extinction condition. Depending on the Lewis number, the instability characteristics is found to be somewhat different. Below the critical Lewis number, $L_C$, the instability possesses primarily a pulsating nature in that the two real solution branches, existing for small wave numbers, merges at a finite wave number, at which a pair of complex conjugate solution branches bifurcate. For Lewis numbers greater than $L_C$, the solution branch for small reactant leakage is found to be purely complex with the maximum growth rate found at a finite wave number, thereby exhibiting a traveling nature. As the reactant leakage parameter is further increased, the instability characteristics turns into a pulsating type, similar to that for L < $L_C$.

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A Fast Determination of Globotriaosylsphingosine in Plasma for Screening Fabry Disease Using UPLC-ESI-MS/MS

  • Yoon, Hye-Ran
    • Mass Spectrometry Letters
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    • 제6권4호
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    • pp.116-119
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    • 2015
  • Globotriaosylsphingosine (lyso-Gb3) is considered as one of the biological marker for Fabry disease. To date, a reliable biomarker that reflects disease severity and progression has not been discovered to guide the management of Fabry disease. A new method included a simple protein precipitation with acetonitrile in 100 μL of plasma following analyte separation on an Phenomenex Kintex- C18 column using a gradient elution (0.1% formic acid in 5-90% acetonitrile). Total run time was within 12 min including sample preparation and MS/MS analysis. The limit of detection and limit of quantitation were 1 ng/mL and 2 ng/mL, respectively. The calibration curve was linear over the concentration range of 2.0-200.0 ng/mL (r2 = 0.9999). Inter-day accuracy and precision at 7 level were 93.4-100.7% with RSD of 0.55-5.97%. Absolute recovery was 97.6-98.6%. The method was applied to human and mice plasma, proved the suitability for quantification of lyso-Gb3 for screening, diagnosis and therapeutic monitoring of Fabry disease patients.

수생식물을 이용한 수질정화에 관한 연구 (Aquatic Plants for Wastewater Treatment)

  • 나규환;권성환;이장훈
    • 한국환경보건학회지
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    • 제22권3호
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    • pp.49-55
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    • 1996
  • Water parsley(Oenanthe javanica(Blume) DC) was raised with varying population density(S) in the laboratory aquarium unit to determine the growth equation. The population density was measure after 7 days. The resultant growth curve was well fit to the equation 1/S = A+B (1/S0) with a high correlation coefficient ($R^2$ = 0.999). The maximum specific absorption rate was $9.011 \times 10^{-5}$ kg $NO_x-N/kg$ water parsley$\cdot$day and $1.31 \times 10^{-5}$ kg $PO_4-P/kg$ water parsley$\cdot$day when the average population density was $2.62 kg/m^2$. The relationship between population density and nutrient absorption rate, the absorption rate of $NO_x-N$ was 5.04~5.24 mg/l$\cdot$day when the population density was $7.51~10.0 $mg/m^2\cdot day$ and the absorption rate of $PO_4-P$ was 0.56~0.78 mg/l$\cdot$day when the population density was 5.02~10.0 $kg/m^2\cdot day$. Taking into account the nutrient absorption rate and growth rate, the population density between $7.0 kg/m^2\cdot day$ and $8.0 kg/m^2 \cdot day$ was selected. The removal rate of nutrient was investigated after 7 days culture. Removal rate of $NO_x-N$ was 95.6~99.95% with initial concentration of 35 mg $NO_x-N/l$, and the removal rate of $PO_4-P$ was also high, indicating 80.24~98.9% with initial concentration of 5.95 mg $PO_x-P/l$.

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Simplified HPLC Method for the Determination of Mirtazapine in Human Plasma and Its Application to Single-dose Pharmacokinetics

  • Gwak Hye-Sun;Lee Na-Young;Chun In-Koo
    • Biomolecules & Therapeutics
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    • 제14권1호
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    • pp.40-44
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    • 2006
  • Mirtazapine is an antidepressant agent with dual action on both the noradrenergic and serotonergic neurotransmitter systems. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of mirtazapine in human plasma. A reversed-phase Cl8 column was used for the determination of mirtazapine with a mobile phase composed of 0.01M ammonium acetate solution (pH 4.2) and acetonitrile (75:25, v/v%) at a flow rate of 1.2 mL/min. Terazosin hydrochloride was used as an internal standard. The fluorescence detector was set at excitation and emission wavelengths of 290 and 350 nm, respectively. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 3 ng/mL. Mirtazapine was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study using plasma samples after oral administration of a single 30 mg dose as mirtazapine base to 8 healthy volunteers. The maximum plasma concentration of mirtazapine was $64.1{\pm}28.0ng/mL$ at 1.8 h, and the area under the curve and elimination half-life were calculated to be $674.1{\pm}218.5ng\;h/mL\;and\;23.4{\pm}3.8h$, respectively.

표면강화 라만분광학을 이용한 nucleobase 유도체 분석 (Surface-Enhanced Raman Scattering Spectroscopic Identification of Genotoxic Nucleobase Adducts)

  • 김재호
    • 분석과학
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    • 제8권3호
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    • pp.313-319
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    • 1995
  • 표면강화 라만분광학을 이용하여 단일전자 산화반응으로 형성된 발암성 벤조피렌 유도체가 nucleobase와 반응하여 생성된 첨가 생성물을 분석하였다. 표면강화 라만분광학을 이용하여 아데닌 또는 구아닌과 같이 각기 다른 종류의 nucleobase와 결합하여 형성된 첨가생성물을 구분하여 분석할 수 있었고 또한 nucleobase 분자의 다른 부분에 결합하여 형성된 이성길체를 라만분광스펙트럼을 통하여 구분하여 분석이 가능하였다. N7Ade-BP에 대한 검정곡선의 선형도 범위는 20 picogram/${\mu}l$에서 800 nanogram/${\mu}l$였고, 본 실험 조건하에서의 검출한계는 $20{\mu}l$의 샘플을 이용하고 20 picogram/${\mu}l$였다.

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전남 연안해역 멸치(Engraulis japonica)의 연령과 초기 성장 (Age and Growth of Anchovy (Engraulis japonica) Juvenile in the Coastal Waters of Chonnam, Korea)

  • 차성식
    • 한국수산과학회지
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    • 제23권5호
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    • pp.385-393
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    • 1990
  • 전남 연안역에 출현하는 멸치 치어의 성장을 연구하기 위하여 전남 연안역의 3개 정점에서 1988년 5월부터 1989년 8월 사이에 정치망으로 멸치를 채집하였으며, 멸치의 연령은 이석에 나타난 성장선수로부터 결정하였다. 체장의 성장은 Gompertz의 성장식으로 표현하면 $$L =5.76{\times}E xp(1.66 \times(1- E xp(-0.44\;t)))$$, 또는 $$L=3.7{\times}E xp(1.99\times(1-E xp(-0.0614\;t)))$$로 표시된다. 20일부터 40일 사이의 평균 일일성장율은 0.38mm/day였으며, 일일성장율은 10일경에 최대를 보인후 서서히 감소하는 것으로 나타났다. 멸치의 성장은 채집시기나 채집장소에 관계없이 거의 일정한 것으로 나타났다.

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아민화 아크릴계 이온교환섬유의 폐수 중 Linear Alkylbenzene Sulfonate 흡착에 관한 연구 (Studies on the Adsorption of Linear Alkylbenzene Sulfonate from Waste Water by Fibrous Aminated Acrylic ion-Exchanger)

  • 황택성;박진원;김원종
    • 폴리머
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    • 제26권4호
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    • pp.516-522
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    • 2002
  • 4급 암모늄기를 관능기로 갖는 아민화 아크릴계 이온교환섬유를 이용하여 연속식 흡착공정 중 linear alkylbenzene sulfonate(LAS)의 흡착특성을 확인하였다. 아민화 아크릴계 이온교환섬유의 LAS흡착성능은 온도가 증가함에 따라 증가하였으며 $40^{\circ}C$에서 최적 흡착성능을 나타내었다. 또한 컬럼 베드 충진비(L/D)의 변화에 따른 LAS 이온의 흡착능은 L/D>2에서 최대 흡착능을 나타내었다. pH 변화에 따른 LAS이온 흡착능은 pH가 증가함에 따라 증가하는 경향을 나타내었고, pH 7에서 최대 흡착능을 나타내었다. 유속변화에 따른 LAS 흡착능은 유속이 증가할수록 낮아졌으며 농도가 높을수록 떨어졌다.