• Title/Summary/Keyword: Model validation

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Phonology and Minimum Temperature as Dual Determinants of Late Frost Risk at Vineyards (발아시기 정밀추정에 의한 포도 만상해 경보방법 개선)

  • Jung, Jea-Eun;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.8 no.1
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    • pp.28-35
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    • 2006
  • An accurate prediction of budburst in grapevines is indispensable for vineyard frost warning system operations in spring because cold tolerance depends heavily on phonology. However, existing frost warning systems utilize only daily minimum temperature forecasts since there is no way to estimate the site-specific phonology of grapevines. A budburst estimation model based on thermal time was used to project budburst dates of two grapevine cultivars (Kyoho and Campbell Early), and advisories were issued depending on phonology as well as temperature. A 'warning' is issued if two conditions are met: the forecasted daily minimum temperature falls below $-1.5^{\circ}C$ and the estimated phonology is within the budburst period. A 'watch' is issued for a temperature range of -1.5 to $+1.5^{\circ}C$ with the same phonology condition. Validation experiments were done at 8 vineyards in Anseong in spring 2005, and the results showed a good agreement with the observations. This method was applied to the climatological normal year (1971-2000) to determine sites with high frost risk at a 30 m grid cell resolution. Among 608,585 grid cells constituting Anseong, 1,059 cells were identified as high risk for growing Kyoho and 2,788 cells for Campbell Early.

Calibration and Validation of SWAT Model for Long Term Simulation of Runoff and Sediment Transport at the Nakdong River Basin (낙동강유역의 장기 유역 유출 및 유사 모의를 위한 SWAT 모형의 검보정)

  • Lee, Eun-Jung;Jang, Eun-Kyung;Kim, Tae-Keun;Hwang, Man-Ha;Kwon, Yong-Sung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.881-881
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    • 2012
  • 낙동강유역에는 4대강 사업으로 8개의 보가 낙동강 본류에 새롭게 설치되었으며, 따라서 상류로부터 유입되는 유사가 보상류에 퇴적되어 하천제방이나 하천구조물의 안전을 위협할 수 있다. 또한 홍수시에는 농경지의 매몰과 저수지의 퇴적현상이 발생하는 등 유역유사에 의한 다양한 문제가 발생할 수 있으며, 강우로부터 유출되는 유사는 강우사상에 따라 빠르게 변할 수 있으나 수체에 즉각적인 영향을 유발하지 않을 경우 만성적인 특성으로 인해 침전물을 계속 이동시키며 축적되는 문제가 발생한다. 따라서 이러한 문제를 사전에 예측하고 낙동강유역에 대한 유역유사관리 대책마련을 마련하기 위해 유역유출과 유사의 이송 및 퇴적양상을 분석하여 유역관리를 위한 자료를 구축할 필요가 있다. 이러한 기초자료 분석을 위해 활용되는 유역모형 중 SWAT(Soil and Water Assessment Tool) 모형은 장기간 유역 유출로 인한 유사 모의를 수행하는데 가장 많이 활용되는 모형이며, 미국 농무성 농업연구소(USDA Agricultural Research Service, ARS)의 Jeff Amold 등에 의해 개발된 모형이다. SWAT 모형은 장기유출 및 유사 발생에 대한 시 공간적 변화를 모의하는 모형으로 넓은 범위의 유역에 대해 일단위 모의 간격으로 최대 100년까지 모의가 가능한 장기유역 모의에 최적화된 모형이다. 본 논문에서는 SWAT 모형을 이용하여 낙동강유역의 장기 유역 유출 및 유사 모의를 수행하기위해 2004년에서 2009년까지의 유출량 자료와 유량-유사량관계곡선 등을 이용하여 본류 및 지류 유출구 주요지점에 대해 검보정을 수행하고자 한다. 모의의 정확도 향상을 위해 안동댐, 임하댐, 영천댐, 합천댐, 남강댐, 밀양댐 및 낙동강 본류 등 총 7개 유역으로 구분하여 SWAT 모형을 구축하였으며, 각 유역별로 유출량과 유사량에 대하여 각각 보정 및 검증을 수행하였다. 낙동강 본류유역 총 7개의 댐 방류량자료와 20개의 대형하수종말처리장 방류량자료를 이용한 낙동강유역의 유출량 보정 및 검증 결과, 모의치가 실측치를 잘 반영하고 있는 것으로 나타났다. 또한 총 11개 지점의 수위관측소에 대해 유사량 측정 성과를 이용한 유사량 보정 및 검증 결과, 강우시 유사량 모의값은 유출량-유사량관계곡선 식을 잘 반영하였으나, 비강우시에는 모의값이 관계곡선 식의 결과값보다 대체적으로 높게 나타났다.

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Optimization Study for the Production of 6-Shogaol-rich Ginger (Zingiber officinale Roscoe) under Conditions of Mild Pressure and High Temperature (가압조건에서 생강 유래 6-shogaol 변환을 위한 가열 조건 최적화)

  • Park, Ho-Young;Ha, Sang Keun;Choi, Jiwon;Choi, Hee-Don;Kim, Yoonsook;Park, Yongkon
    • Korean Journal of Food Science and Technology
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    • v.46 no.5
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    • pp.588-592
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    • 2014
  • Under optimized condition mild pressure in combination with specific temperature for heat treatment transform the 6-gingerol into 6-shogaol. The purpose of this study was to optimize the conditions used for heat treatment under pressure for increasing 6-shogaol content in ginger (Zingiber officinale Roscoe). A central composite experimental design was used to evaluate the effects of application temperature ($70-130^{\circ}C$) and temperature-holding time (95-265 min) on the transformation of 6-shogaol. The experimental values were shown to be in significantly good agreement with the predicted values (adjusted determination coefficient, $R^2{_{Adj}}=0.9857$). 6-Shogaol content increased as the application temperature and temperature-holding time increased. By analyzing the response surface plots, the optimum conditions of heat treatment (temperature and time) for increasing 6-shogaol content were found to be $127^{\circ}C$ and 109 min, respectively. Under these optimal conditions, the predicted 6-shogaol content was 3.98 mg/g dried ginger. The adequacy of the model equation for predicting the optimum response values was effectively verified by the validation data.

Quantitative Analysis of Acid Value, Iodine Value and Fatty Acids Content in Sesame Oils by NIRS (근적외선분광광도법을 이용한 참기름의 산가, 요오드가, 지방산정량법에 관한 연구)

  • Kim, Jae-Kwan;Lee, Myung-Jin;Kim, Myung-Gill;Kim, Kyung-A;Park, Eun-Mi;Kim, Young-Sug;Ko, Hoan-Uck;Son, Jin-Seok
    • Journal of Food Hygiene and Safety
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    • v.21 no.4
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    • pp.204-212
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    • 2006
  • This study was conducted to investigate the possibility of rapid and non-des tructive evalution of AV (Acid Value), IV (Iodine Value) and fatty acids in sesame oils. The samples were scanned over the range $400\sim2500nm$ using transmittance spectrum of NIRS(Near-infrared spectroscopy). A calibration equation calculated by MPLS regression technique was developed and correlation coefficient of determination for AV, IV, palmitic acid, stearic acid, linoleic acid and linolenic acid content were 0.9907, 0.9677, 0.9527, 0.9210, 0.9829, 0.9736 and 0.9709 respectively. The validation model for measuring the AV content had R of 0.989, SEP of 0.058 and IV content had R of 0.944, SEP of 0.562 and palmitic acid content had R of 0.924, SEP of 0.194 and stearic acid content had R of 0.717, SEP of 0.168 and oleic acid content had R of 0.989, SEP of 0.221 and linoleic acid content had R of 0.967, SEP of 0.297 and linolenic acid content had R of 0.853, SEP of 0.480 by MPLS. The obtained results indicate that the NIRS procedure can potentially be used as a non-destructive analysis method for the purpose of rapid and simple measurement of AV, IV and fatty acids in sesame oils.

Protein Interaction Possibility Ranking Method based on Domain Combination (도메인 조합 기반 단백질 상호작용 가능성 순위 부여 기법)

  • Han Dong-Soo;Kim Hong-Song;Jong Woo-Hyuk;Lee Sung-Doke
    • Journal of KIISE:Computing Practices and Letters
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    • v.11 no.5
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    • pp.427-435
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    • 2005
  • With the accumulation of protein and its related data on the Internet, many domain based computational techniques to predict protein interactions have been developed. However, most of the techniques still have many limitations to be used in real fields. They usually suffer from a low accuracy problem in prediction and do not provide any interaction possibility ranking method for multiple protein pairs. In this paper, we reevaluate a domain combination based protein interaction prediction method and develop an interaction possibility ranking method for multiple protein pairs. Probability equations are devised and proposed in the framework of domain combination based protein interaction prediction method. Using the ranking method, one can discern which protein pair is more probable to interact with each other than other protein pairs in multiple protein pairs. In the validation of the ranking method, we revealed that there exist some correlations between the interacting probability and the precision of the prediction in case of the protein pair group having the matching PIP(Primary Interaction Probability) values in the interacting or non interacting PIP distributions.

New Methods for Correcting the Atmospheric Effects in Landsat Imagery over Turbid (Case-2) Waters

  • Ahn Yu-Hwan;Shanmugam P.
    • Korean Journal of Remote Sensing
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    • v.20 no.5
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    • pp.289-305
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    • 2004
  • Atmospheric correction of Landsat Visible and Near Infrared imagery (VIS/NIR) over aquatic environment is more demanding than over land because the signal from the water column is small and it carries immense information about biogeochemical variables in the ocean. This paper introduces two methods, a modified dark-pixel substraction technique (path--extraction) and our spectral shape matching method (SSMM), for the correction of the atmospheric effects in the Landsat VIS/NIR imagery in relation to the retrieval of meaningful information about the ocean color, especially from Case-2 waters (Morel and Prieur, 1977) around Korean peninsula. The results of these methods are compared with the classical atmospheric correction approaches based on the 6S radiative transfer model and standard SeaWiFS atmospheric algorithm. The atmospheric correction scheme using 6S radiative transfer code assumes a standard atmosphere with constant aerosol loading and a uniform, Lambertian surface, while the path-extraction assumes that the total radiance (L/sub TOA/) of a pixel of the black ocean (referred by Antoine and Morel, 1999) in a given image is considered as the path signal, which remains constant over, at least, the sub scene of Landsat VIS/NIR imagery. The assumption of SSMM is nearly similar, but it extracts the path signal from the L/sub TOA/ by matching-up the in-situ data of water-leaving radiance, for typical clear and turbid waters, and extrapolate it to be the spatially homogeneous contribution of the scattered signal after complex interaction of light with atmospheric aerosols and Raleigh particles, and direct reflection of light on the sea surface. The overall shape and magnitude of radiance or reflectance spectra of the atmospherically corrected Landsat VIS/NIR imagery by SSMM appears to have good agreement with the in-situ spectra collected for clear and turbid waters, while path-extraction over turbid waters though often reproduces in-situ spectra, but yields significant errors for clear waters due to the invalid assumption of zero water-leaving radiance for the black ocean pixels. Because of the standard atmosphere with constant aerosols and models adopted in 6S radiative transfer code, a large error is possible between the retrieved and in-situ spectra. The efficiency of spectral shape matching has also been explored, using SeaWiFS imagery for turbid waters and compared with that of the standard SeaWiFS atmospheric correction algorithm, which falls in highly turbid waters, due to the assumption that values of water-leaving radiance in the two NIR bands are negligible to enable retrieval of aerosol reflectance in the correction of ocean color imagery. Validation suggests that accurate the retrieval of water-leaving radiance is not feasible with the invalid assumption of the classical algorithms, but is feasible with SSMM.

Validation of the Measure of Health Literacy for the Elderly (고령자의 건강정보이해능력(Health Literacy) 측정도구 타당화)

  • Chun, Heeran;Cho, Sung-il;Kim, Il-Ho
    • Korean Public Health Research
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    • v.44 no.4
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    • pp.99-109
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    • 2018
  • Objective : Health literacy (HL) is, defined as "the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." Being old is one of the main risk factors with limited health literacy. This study aims to adapt Chew's health literacy scale into the Korean language and validate the scale for the use of the elderly. Methods : Data were drawn from the '2016 Seoul Survey on Elderly Health and Functional Assessment, which includes a total of 725 people aged 60 to 79. The sample was randomly divided into two groups for reliability and validity tests of the modified Chew's scale of 8 items. The Korean version of the questionnaire was developed by group translation, expert reviews, and forward-backward translation. Exploratory and confirmatory factor analyses were conducted to assess and validate the factor structure of the scale. Results : Results suggest the two-factor structure ("Understanding" and "Applying" of HL) with 8 items. Exploratory factor analyses of the first sample (n=400) revealed that the internal reliability of the scale was high (Cronbach's ${\alpha}=.904$). Principal axis factoring extracted two factors ("Understanding" and "Applying" of HL) and explained 78.3% of total variance (KMO=.872, Bartlett's ${\chi}^2=2431.3$, df=28, p<.001). Confirmatory factor analysis of the second sample (n=325) was performed and the two-factor model was supported (GFI=.960, CFI=.979, TLI=.969, RMSEA=0.075). Conclusions : This study provides evidence for adequate criterion and validity of the health literacy scale for the community dwelling elderly in Korea.

CFD Simulation of the Self-propulsion of a damaged Car Ferry in Waves (손상된 카페리 선박의 파랑중 자항상태 CFD 해석)

  • Kim, Je-In;Park, Il-Ryong;Kim, Jin;Kim, Kwang-Soo;Kim, Yoo-Chul
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.1
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    • pp.34-46
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    • 2019
  • This paper provides the numerical results for the self-propulsion performance in waves of a car ferry vessel with damage in one of its twin-screw propulsion systems without flooding the engine room. The numerical simulations were carried out according to the Safe Return to Port (SRtP) regulation made by the Lloyd's register, where the regulation requires that damaged passenger ships should have an ability to return to port with a speed of 6 knots in a Beaufort 8 sea condition. For the validation of the present numerical analysis study, the resistance performance and the self-propulsion performance of the car ferry in intact and damaged conditions in calm water were calculated, which showed a satisfactory agreement with the model test results of Korea Research Institute of Ship and Ocean engineering (KRISO). Finally, the numerical simulation of self-propulsion performance in waves of the damaged car ferry ship was carried out for a normal sea state and for a Beaufort 8 sea state, respectively. The estimated average Brake Horse Power (BHP) for keeping the damaged car ferry ship advancing at a speed of 6 knots in a Beaufort 8 sea state reached about 47% of BHP at MCR condition or about 56% of BHP at NCR condition of the engine determined at the design state. In conclusion, it can be noted that the engine power of the damaged car ferry ship in single propulsion condition is sufficient to satisfy the SRtP requirement.

Construct Validation of the Sensory Profile for Children with Congenital Cerebral Palsy (뇌성마비 아동을 대상으로 한 감각프로파일(Sensory Profile)의 구성타당도 연구)

  • Yoo, Doo Han;Hong, Deok Gi;Hwang, Sun Jung
    • 재활복지
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    • v.18 no.4
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    • pp.315-330
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    • 2014
  • The purpose of this study was to verify the construct validity of the Sensory Profile for children with congenital cerebral palsy. Parents of 87 children(the ages of 3 to 10) with congenital cerebral palsy participated in this study. The data were analyzed through Winstep version 3.81 using the Rasch model to examine the uni-dimensionality of the fit of each item, the distribution of difficulty of each item, and the reliability and appropriateness of the rating scale. Based on a Rasch analysis, four out of the 87 children were considered to be inappropriate participants, and 15 item of the Sensory Profile was determined to be an inappropriate item. The items of high-level difficulty are needed as new items of the Korean Sensory Profile. The rating scale of three categories were appropriate than those of the five categories. The person and item separation reliability of three categories was above 0.90, which is a relatively excellent value. Finally, it will be need to verify of validity for Korean version of Sensory Profile, to develop new item of a high level of difficulty and convert into three point rating scale.

Validation of Korean version of Professional quality of life(K-ProQOL) for nurses through confirmatory factor analysis (확인적 요인분석을 통한 한국어판 전문직 삶의 질(K-ProQOL) 도구의 타당화 : 간호사를 중심으로)

  • Kim, Ju-I;Choi, Hyoung-Shim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.3
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    • pp.243-251
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    • 2019
  • This study was undertaken to validate and assess the reliability of the Korean version of professional quality of life scale (K-ProQOL) that measures the compassion satisfaction, compassion fatigue and burnout among clinical nurses in Korea. We conducted an internal consistency reliability and construct validity by applying confirmatory factor analysis using SPSS WIN (24.0) and AMOS (18.0). Survey data were collected from 210 nurses working at three tertiary hospitals located in Seoul. Reliable internal consistency was achieved for the K-ProQOL, with a Cronbach's alpha for the total scale and three sub scale values of 0.72-0.90. Factor loadings on three subscales of the 30 items considered ranged from 0.25 to 0.82. The model was validated by confirmatory factor analysis (RMSEA 0.05-0.1, GFI >0.7, CFI >0.7). The findings of this study demonstrate that the K-ProQOL has satisfactory construct validity and reliability to measure compassion satisfaction, compassion fatigue and burnout among clinical nurses in Korea. This is the first study assessing the validity and reliability of the Korean version of professional quality of life scale for clinical nurses in Korea.