• Title/Summary/Keyword: quantitative models

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A Study on Basin Characteristics of Small Stream System (소하천 수계의 유역특성에 관한 연구)

  • An, Sang-Jin;Yun, Yeong-Nam;Gang, Gwan-Won
    • Water for future
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    • v.10 no.1
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    • pp.71-77
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    • 1977
  • The stream morphological characteristics of a watershed play a significant role in the analysis of rainfall-runoff relations in a river basin and a quantitative description of these characteristics is essential for determining the appropriate values of physical parameters of a watershed which usually are input data for rainfall-runoff simulation models. In this study the stream morphological characteristics of the Gab River basin, which is one of the three major tributaries of Geum River, was determined quantitatively by the Horton-Strahler's method. The result showed that the Gab River System was developed very closely to the patterns generally described by the laws of Horton. The basic relations concerning the morphological characteristics deriveed in this study are the relations of stream length, and average stream slope, the stream length-drainage area relation, relative height-relative drainage area relation, and the relation between the proportional stream order and drainage area. No correlation analysis was possible between the morphological parameters and the streamflow due to non-existence of the stage gauging stations on the Gab River System.

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Relationship between Hydrologic Flux of Total Organic Carbon and Gross Primary Production (총 유기탄소의 수문학적 플럭스와 총 일차생산량 사이의 관계분석)

  • Park, Yoonkyung;Cho, Seonju;Choi, Daegyu;Kim, Sangdan
    • Journal of Wetlands Research
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    • v.14 no.4
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    • pp.503-518
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    • 2012
  • Models estimating carbon budget at land surface are mainly interested in vertical flux of carbon. On the other hand, studies on horizontal flux are obviously lacked to confirm that relationship between the hydrological flux of organic carbon discharged from catchment and terrestrial carbon production, a relation between Total Organic Carbon(TOC) and Gross Primary Production(GPP) tried analysis through cross correlation. The best correlation structure is correlation between GPP and TOC of flow-weighted mean concentration from watershed without delay. Furthermore, cross correlation analysis was performed by consider periodicity. The correlation between TOC and GPP in summer was similar to correlation without periodicity. Therefore, correlation between GPP and TOC was most regulated by the correlation between GPP and TOC at summer. As a result, the vegetation carbon and organic carbon from watershed is recognized a close relationship on the seasonal. Therefore, future research is correlation analyzing between vegetation variables according season, GPP and TOC, we are expected to use quantitative understanding that horizontal flux flow of carbon from the surface.

Applicability Evaluation to Grid-based Rainfall-Runoff-Sediment Model for Sediment Discharge Estimation (격자기반 강우-유출-유사 모형의 유사량 산정에 관한 적용성 평가)

  • Choi, Hyun Gu;Park, Jun Hyung;Han, Kun Yeun
    • Journal of Wetlands Research
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    • v.19 no.1
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    • pp.132-143
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    • 2017
  • It is essential to obtain periodic sediment discharge data in a river in order to minimize problems that may arise from the erosion, transport, and deposition of sediment. However, it is difficult to estimate sediment discharge by the sediment discharge measurement plan in Korea at present, and empirical fomulas or numerical models are used to replace them. This paper has applied the K-DRUM model, a grid-based rainfall-runoff-sediment model, to estimate sediment discharge and ensure the continuity of the data in the watershed. Discharge and sediment load in 17 watersheds were estimated and the applicability of the model was analyzed through comparisons with measured data. For quantitative evaluation, NSE, PBIAS and RSR items were used, and discharge results reflected the tendency of rainfall and showed high statistical value. In case of sediment discharge, the soil erosion process of the watershed is physically well reflected. When the calibration was performed using the measure data, the applicability seems to be excellent in estimating the continuous sediment discharge data in the real watershed.

A Study on Industry Problem Based Professional Practice Model: Based on Gyeongbuk K University Case Study (산업체 PBL기반 기업애로해결형 현장실습 모형 연구: 경북지역 K대학 사례를 중심으로)

  • Lee, Seok-moon;Jo, Young-jun
    • Journal of Practical Engineering Education
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    • v.12 no.1
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    • pp.93-100
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    • 2020
  • To qualitative improvement in addition to the quantitative growth of field placement, efforts to reduce short-term (4 weeks) and mid-term professional practice (8 weeks) and to increase the proportion of long-term term professional practice (12 weeks or more) are increasing at university sites. There are the problems: the absence of systematic and specialized field placement curriculum of the short-term and mid-term professional practice, the participation of university field placement increases, companies do not prefer to participate in its program and students hesitate to apply to long-term practice due to their major. In order to solve these problems, this paper proposes the IPBP(Industry Problem Based professional Practice) based on Gyeongbuk K University which the students solve the company's difficulties during the field placement with their professor if need. In order to build a win-win field practice culture with participating companies, we suggest that the IPBP solution field practice presented in this paper is one of the good models.

Optimization and kinetic modeling for bioconversion of cheese whey to Ganoderma lucidum in batch fermentations

  • Song, Min-Gyeong;Lee, Hwan-Yeong;Hwang, Seok-Hwan
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.381-384
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    • 2002
  • Response surface methodology (RSM) was successfully applied to optimize for the production of Ganoderma lucidum in batch fermentations using the whey (40,000 mg latose/L) as substrate. This study was performed according to the central composite design (CCD) with respect to pH and temperature, where the designed intervals were 3.3$22.9^{\circ}C$$37.1^{\circ}C$, respectively. A second-order factorial design of the experiments was used to build empirical models providing a quantitative interpretation of the relationships between the two variables. The optimum conditions to maximize the production of G. lucidum were pH 4.2 and $28.3^{\circ}C$. At optimum conditions, the mycelial dry weight (MDW) and residual soluble COD (SCOD) were simultaneously used to evaluate the biokinetic coefficients assocoated with substrate inhibition model by nonlinear least squares method with 95% confidence interval. The. maximum microbial growth rates (${\mu}m$), half saturation coefficient ($K_s$), and the inhibition substrate concentration ($K_{is}$) were determined to be 0.095 l/hr, 128,000 mg SCOD/L and 49,000 mg SCOD/L, respectively. And the microbial yield coefficient (Y), biomass decay rate coefficient ($K_d$), and the maintenance energy coefficient ($m_s$) were determined to be 0.37 mg MDW/mg SCOD, 0.001 1/hr, and 0.0015 1/hr, respectively.

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Association between Dietary Acid Load and Insulin Resistance: Tehran Lipid and Glucose Study

  • Moghadam, Sajjad Khalili;Bahadoran, Zahra;Mirmiran, Parvin;Tohidi, Maryam;Azizi, Fereidoun
    • Preventive Nutrition and Food Science
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    • v.21 no.2
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    • pp.104-109
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    • 2016
  • In the current study, we investigated the longitudinal association between dietary acid load and the risk of insulin resistance (IR) in the Tehranian adult population. This longitudinal study was conducted on 925 participants, aged 22~80 years old, in the framework of the third (2006~2008) and fourth (2009~2011) phases of the Tehran Lipid and Glucose Study. At baseline, the dietary intake of subjects was assessed using a validated semi-quantitative food frequency questionnaire, and the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores were calculated at baseline. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up; IR was defined according to optimal cut-off values. Multiple logistic regression models were used to estimate the risk of IR according to the PRAL and NEAP quartile categories. Mean age and body mass index of the participants were 40.3 years old of $26.4kg/m^2$, respectively. Mean PRAL and NEAP scores were -11.2 and 35.6 mEq/d, respectively. After adjustment for potential confounders, compared to the lowest quartile of PRAL and NEAP, the highest quartile was accompanied with increased risk of IR [odds ratio (OR)=2.81, 95% confidence interval (CI)=1.32~5.97 and OR=2.18, 95% CI=1.03~4.61, respectively]. Our findings suggest that higher acidic dietary acid-base load, defined by higher PRAL and NEAP scores, may be a risk factor for the development of IR and related metabolic disorders.

Prediction of Forest Fire Hazardous Area Using Predictive Spatial Data Mining (예측적 공간 데이터 마이닝을 이용한 산불위험지역 예측)

  • Han, Jong-Gyu;Yeon, Yeon-Kwang;Chi, Kwang-Hoon;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.9D no.6
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    • pp.1119-1126
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    • 2002
  • In this paper, we propose two predictive spatial data mining based on spatial statistics and apply for predicting the forest fire hazardous area. These are conditional probability and likelihood ratio methods. In these approaches, the prediction models and estimation procedures are depending un the basic quantitative relationships of spatial data sets relevant forest fire with respect to selected the past forest fire ignition areas. To make forest fire hazardous area prediction map using the two proposed methods and evaluate the performance of prediction power, we applied a FHR (Forest Fire Hazard Rate) and a PRC (Prediction Rate Curve) respectively. In comparison of the prediction power of the two proposed prediction model, the likelihood ratio method is mort powerful than conditional probability method. The proposed model for prediction of forest fire hazardous area would be helpful to increase the efficiency of forest fire management such as prevention of forest fire occurrence and effective placement of forest fire monitoring equipment and manpower.

Computer-Assisted Map Analysis for Planning Forest Road Network (컴퓨터 지도분석(地圖分析)을 이용(利用)한 임도계획(林道計劃))

  • Lee, Kyu-Sung
    • Journal of Korean Society of Forest Science
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    • v.80 no.3
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    • pp.317-325
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    • 1991
  • Route projection of forest road involves several constraints ranging from construction cost to environmental impacts. This study is designed to assess the capability of computer-assisted map analysis techniques for deriving several alternatives of forest road planning. Three cartographic models are presented to address the limit of slope, soil erosion, and aesthetic value in designing forest roads over a relatively small size of mountainous forest. Primary spatial analysis techniques used are distance measurements and connectivity analysis. The fundamental approach used was to generate a set of friction maps in which each friction map represents a combined restriction for a forest road projection. Products of the spatial analysis are compared by both qualitative and quantitative methods. The results demonstrate that computer-assisted map analysis has a potential to solve rather complex problems of forest road planning by providing several alternatives effectively.

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Estimation of Physical-Chemical Property and Environmental Fate of Benzoyl peroxide Using (Q)SAR

  • Kim, Mi-Kyoung;Kim, Su-Hyon;Heekyung Bae;Sanghwan Song;Hyunju Koo;Jeon, Seong-Hwan;Na, Jin-Gyun;Park, Kwangsik;Lee, Moon-Soon
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • 2002.10a
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    • pp.154-154
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    • 2002
  • Benzoyl peroxide is a High Production Volume Chemical, which is produced about 1,375 tons/year in Korea as of 2001 survey. The substance is mainly used as initiators in polymerization, catalysts in the plastics industry, bleaching agents for flour and medication for acne vulgaris. The substance is one of seven chemicals of which human health and environmental risks are being assessed by National Institute of Environmental Research (NIER) under the frame of OECD SIDS Program. In this study, Quantitative Structure-Activity Relationships (QSAR) is used for getting adequate information on the physical-chemical property and the environmental fate of this chemical. For the assessment of benzoyl peroxide, models such as MPBPWIN for vapor pressure, KOWWIN for octanol/water partition coefficient, HENRYWIN for Henry's Law constant, AOPWIN for photolysis and BCFWN for bioconcentration factor (BCF) were used. These (Q)SAR model programmes were worked by using the SHILES (Simplified Molecular Input Line Entry System) notations. The physical-chemical properties and the environmental fate of benzoyl peroxide were estimated as followed : vapor pressure =0.00929 Pa, Log Kow = 3.43, Henry's Law constant = 0.00000354 atm-㎥/mole at 25 $^{\circ}C$, the half-life of photodegradation = 3 days, bioconcentration factor (BCF) = 92

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Use of Near-Infrared Spectroscopy for Estimating Lignan Glucosides Contents in Intact Sesame Seeds

  • Kim, Kwan-Su;Park, Si-Hyung;Shim, Kang-Bo;Ryu, Su-Noh
    • Journal of Crop Science and Biotechnology
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    • v.10 no.3
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    • pp.185-192
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    • 2007
  • Near-infrared spectroscopy(NIRS) was used to develop a rapid and efficient method to determine lignan glucosides in intact seeds of sesame(Sesamum indicum L.) germplasm accessions in Korea. A total of 93 samples(about 2 g of intact seeds) were scanned in the reflectance mode of a scanning monochromator, and the reference values for lignan glucosides contents were measured by high performance liquid chromatography. Calibration equations for sesaminol triglucoside, sesaminol($1{\rightarrow}2$) diglucoside, sesamolinol diglucoside, sesaminol($1{\rightarrow}6$) diglucoside, and total amount of lignan glucosides were developed using modified partial least square regression with internal cross validation(n=63), which exhibited lower SECV(standard errors of cross-validation), higher $R^2$(coefficient of determination in calibration), and higher 1-VR(ratio of unexplained variance divided by variance) values. Prediction of an external validation set(n=30) showed a significant correlation between reference values and NIRS estimated values based on the SEP(standard error of prediction), $r^2$(coefficient of determination in prediction), and the ratio of standard deviation(SD) of reference data to SEP, as factors used to evaluate the accuracy of equations. The models for each glucoside content had relatively higher values of SD/SEP(C) and $r^2$(more than 2.0 and 0.80, respectively), thereby characterizing those equations as having good quantitative information, while those of sesaminol($1{\rightarrow}2$) diglucoside showing a minor quantity had the lowest SD/SEP(C) and $r^2$ values(1.7 and 0.74, respectively), indicating a poor correlation between reference values and NIRS estimated values. The results indicated that NIRS could be used to rapidly determine lignan glucosides content in sesame seeds in the breeding programs for high quality sesame varieties.

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