• 제목/요약/키워드: Cross - Validation

검색결과 1,017건 처리시간 0.026초

공간통합 모델을 적용한 암괴류 및 애추 지형 분포가능지 추출 (Extraction of Potential Area for Block Stream and Talus Using Spatial Integration Model)

  • 이성호;장동호
    • 한국지형학회지
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    • 제26권2호
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    • pp.1-14
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    • 2019
  • This study analyzed the relativity between block stream and talus distributions by employing a likelihood ratio approach. Possible distribution sites for each debris slope landform were extracted by applying a spatial integration model, in which we combined fuzzy set model, Bayesian predictive model, and logistic regression model. Moreover, to verify model performance, a success rate curve was prepared by cross-validation. The results showed that elevation, slope, curvature, topographic wetness index, geology, soil drainage, and soil depth were closely related to the debris slope landform sites. In addition, all spatial integration models displayed an accuracy of over 90%. The accuracy of the distribution potential area map of the block stream was highest in the logistic regression model (93.79%). Eventually, the accuracy of the distribution potential area map of the talus was also highest in the logistic regression model (97.02%). We expect that the present results will provide essential data and propose methodologies to improve the performance of efficient and systematic micro-landform studies. Moreover, our research will potentially help to enhance field research and topographic resource management.

Variation of Days to Heading and Association Study for Different Location of Some Rice Genetic Resources

  • Tae-ho Ham;Mi-Young Park;So-Myeong Lee;Soon-Wook Kwon;Joohyun Lee
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2022년도 추계학술대회
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    • pp.265-265
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    • 2022
  • Increased temperature caused by global warming has become a significant problem for the growth and production of crops. A high temperature has a direct or an indirect effect on crops, leading to a significant yield loss. The damage of a high temperature stress to rice depends on its developmental stage. In present study, we performed evaluate the heading date in different location, Yeoju and Miryang, during growth of Korean rice core set. The heading date for the 223 rice accession were evaluated in Yeoju City (37°23' 127°57') and Miryang City (35°50', 128°72') located on middle and southern part of Korea, respectively. The average temperature of a day was higher in Miryang during entire growth stage. Here, total 222 KRICE-Core set was analyzed by GWAS for the high temperature effect. GWAS results revealed the Chr07_26954556, a lead SNPs were significantly associated with delaying heading date of KRICE-Core set. Significance threshold was set with 6.0 > -log10(P), and Cross-Validation (CV) error suggested an optimal K value of 5 for the population based on the lowest cross-validation error K = 5.

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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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    • 제10권3호
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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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Use of Near-Infrared Spectroscopy for Estimating Fatty Acid Composition in Intact Seeds of Rapeseed

  • Kim, Kwan-Su;Park, Si-Hyung;Choung, Myoung-Gun;Jang, Young-Seok
    • Journal of Crop Science and Biotechnology
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    • 제10권1호
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    • pp.13-18
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    • 2007
  • Near-infrared spectroscopy(NIRS) was used as a rapid and nondestructive method to determine the fatty acid composition in intact seed samples of rapeseed(Brassica napus L.). A total of 349 samples(about 2 g of intact seeds) were scanned in the reflectance mode of a scanning monochromator, and the reference values for fatty acid composition were measured by gas-liquid chromatography. Calibration equations for individual fatty acids were developed using the regression method of modified partial least-squares with internal cross validation(n=249). The equations had low SECV(standard errors of cross-validation), and high $R^2$(coefficient of determination in calibration) values(>0.8) except for palmitic and eicosenoic acid. Prediction of an external validation set(n=100) showed 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. The models developed in this study had relatively higher values(> 3.0 and 0.9, respectively) of SD/SEP(C) and $r^2$ for oleic, linoleic, and erucic acid, characterizing those equations as having good quantitative information. The results indicated that NIRS could be used to rapidly determine the fatty acid composition in rapeseed seeds in the breeding programs for high quality rapeseed oil.

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베이지안 예측모델을 활용한 농업 및 인공 인프라의 산사태 재해 위험 평가 (Landslide Risk Assessment of Cropland and Man-made Infrastructures using Bayesian Predictive Model)

  • 알-마문;장동호
    • 한국지형학회지
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    • 제27권3호
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    • pp.87-103
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    • 2020
  • The purpose of this study is to evaluate the risk of cropland and man-made infrastructures in a landslide-prone area using a GIS-based method. To achieve this goal, a landslide inventory map was prepared based on aerial photograph analysis as well as field observations. A total of 550 landslides have been counted in the entire study area. For model analysis and validation, extracted landslides were randomly selected and divided into two groups. The landslide causative factors such as slope, aspect, curvature, topographic wetness index, elevation, forest type, forest crown density, geology, land-use, soil drainage, and soil texture were used in the analysis. Moreover, to identify the correlation between landslides and causative factors, pixels were divided into several classes and frequency ratio was also extracted. A landslide susceptibility map was constructed using a bayesian predictive model (BPM) based on the entire events. In the cross validation process, the landslide susceptibility map as well as observation data were plotted with a receiver operating characteristic (ROC) curve then the area under the curve (AUC) was calculated and tried to extract a success rate curve. The results showed that, the BPM produced 85.8% accuracy. We believed that the model was acceptable for the landslide susceptibility analysis of the study area. In addition, for risk assessment, monetary value (local) and vulnerability scale were added for each social thematic data layers, which were then converted into US dollar considering landslide occurrence time. Moreover, the total number of the study area pixels and predictive landslide affected pixels were considered for making a probability table. Matching with the affected number, 5,000 landslide pixels were assumed to run for final calculation. Based on the result, cropland showed the estimated total risk as US $ 35.4 million and man-made infrastructure risk amounted to US $ 39.3 million.

공간예측모형에 기반한 산사태 취약성 지도 작성과 품질 평가 (Mapping Landslide Susceptibility Based on Spatial Prediction Modeling Approach and Quality Assessment)

  • 알-마문;박현수;장동호
    • 한국지형학회지
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    • 제26권3호
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    • pp.53-67
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    • 2019
  • The purpose of this study is to identify the quality of landslide susceptibility in a landslide-prone area (Jinbu-myeon, Gangwon-do, South Korea) by spatial prediction modeling approach and compare the results obtained. For this goal, a landslide inventory map was prepared mainly based on past historical information and aerial photographs analysis (Daum Map, 2008), as well as some field observation. Altogether, 550 landslides were counted at the whole study area. Among them, 182 landslides are debris flow and each group of landslides was constructed in the inventory map separately. Then, the landslide inventory was randomly selected through Excel; 50% landslide was used for model analysis and the remaining 50% was used for validation purpose. Total 12 contributing factors, such as slope, aspect, curvature, topographic wetness index (TWI), elevation, forest type, forest timber diameter, forest crown density, geology, landuse, soil depth, and soil drainage were used in the analysis. Moreover, to find out the co-relation between landslide causative factors and incidents landslide, pixels were divided into several classes and frequency ratio for individual class was extracted. Eventually, six landslide susceptibility maps were constructed using the Bayesian Predictive Discriminant (BPD), Empirical Likelihood Ratio (ELR), and Linear Regression Method (LRM) models based on different category dada. Finally, in the cross validation process, landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract success rate curve. The result showed that Bayesian, likelihood and linear models were of 85.52%, 85.23%, and 83.49% accuracy respectively for total data. Subsequently, in the category of debris flow landslide, results are little better compare with total data and its contained 86.33%, 85.53% and 84.17% accuracy. It means all three models were reasonable methods for landslide susceptibility analysis. The models have proved to produce reliable predictions for regional spatial planning or land-use planning.

운동중의 임피던스 신호에서 상호상관 관계를 이용한 특성점의 검출 (Delection of Distinctive Points in Impedance Cardiogram during Exercise by Cross-Correlation Method)

  • 오인식;송철규;김덕원;차일환
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1991년도 추계학술대회
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    • pp.93-95
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    • 1991
  • As the ensemble averaged dZ/dt signal during exercise is smoothed, it is difficult to find the distinctive marks. The cross correlation function was made use of estmating these marks. LVET was calculated based on the calculated parameters of the characteristic points. For the accuracy validation, LVET calculated by hand, by the ensemble average and the cross correl at ion were compared.

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크기가 다른 단면을 가진 평행한 두 채널을 연결하는 협소유로의 맥동유동에 관한 수치해석 (Numerical Investigation of the Flow Pulsation in the Gap connecting with Two Parallel Channels with Different Cross-section Areas)

  • 서정식;홍성호;신종근;최영돈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2810-2815
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    • 2008
  • Flow pulsation in the gap connecting with two parallel channels is investigated by RANS and URANS approaches. The two parallel channels are connected by a small channel called for a gap. The parallel channels are designed to have different cross section area with its ratio of 0.5. Computations are conducted using a CFX 11.0 code. The bulk Reynolds number is 60,000. Predicted results are compared with the previous experimental result. Mean velocity profile at the center of gap region are compared with experiments for its validation. Spectral analysis on the lateral velocity in the center of the gap is presented. Auto and cross correlation for the axial-flow velocity pattern are presented. The unsteady structure of the flow pulsation was visualized in the region of the gap in the parallel channel.

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Validation of electromagnetic physics models and electron range in Geant4 Brachytherapy application

  • A. Albqoor ;E. Ababneh ;S. Okoor;I. Zahran
    • Nuclear Engineering and Technology
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    • 제55권1호
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    • pp.229-237
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    • 2023
  • The mechanics underlying photon and electron interactions was validated using our developed Brachytherapy computer code for high Dose Rate (HDR). By comparing the photon cross-section utilizing multiple physics libraries in the developed code, the results were benchmarked against experimental and theoretical findings. Klein-Nishina and experimental cross-section results were in good agreement with the Livermore library results. For two therapeutically relevant materials, the first scattered electron range was measured within 1 mm and 2 mm, which has significant implications for the interpretation of the kernel dose spikes observed in previous research.

Transfer-learning-based classification of pathological brain magnetic resonance images

  • Serkan Savas;Cagri Damar
    • ETRI Journal
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    • 제46권2호
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    • pp.263-276
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    • 2024
  • Different diseases occur in the brain. For instance, hereditary and progressive diseases affect and degenerate the white matter. Although addressing, diagnosing, and treating complex abnormalities in the brain is challenging, different strategies have been presented with significant advances in medical research. With state-of-art developments in artificial intelligence, new techniques are being applied to brain magnetic resonance images. Deep learning has been recently used for the segmentation and classification of brain images. In this study, we classified normal and pathological brain images using pretrained deep models through transfer learning. The EfficientNet-B5 model reached the highest accuracy of 98.39% on real data, 91.96% on augmented data, and 100% on pathological data. To verify the reliability of the model, fivefold cross-validation and a two-tier cross-test were applied. The results suggest that the proposed method performs reasonably on the classification of brain magnetic resonance images.