• Title/Summary/Keyword: Area under curve

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

  • Al, Mamun;Park, Hyun-Su;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.3
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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.

Effects of gut microbiota on the pharmacokinetics of protopanaxadiol ginsenosides Rd, Rg3, F2, and compound K in healthy volunteers treated orally with red ginseng

  • Kim, Jeon-Kyung;Choi, Min Sun;Jeung, Woonhee;Ra, Jehyeon;Yoo, Hye Hyun;Kim, Dong-Hyun
    • Journal of Ginseng Research
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    • v.44 no.4
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    • pp.611-618
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    • 2020
  • Background: It is well recognized that gut microbiota is involved in the biotransformation of ginsenosides by converting the polar ginsenosides to nonpolar bioactive ginsenosides. However, the roles of the gut microbiota on the pharmacokinetics of ginsenosides in humans have not yet been fully elucidated. Methods: Red ginseng (RG) or fermented red ginseng was orally administered to 34 healthy Korean volunteers, and the serum concentrations of the ginsenosides were determined using liquid chromatography-tandem mass spectrometry. In addition, the fecal ginsenoside Rd- and compound K (CK)eforming activities were measured. Then, the correlations between the pharmacokinetic profiles of the ginsenosides and the fecal ginsenoside-metabolizing activities were investigated. Results: For the RG group, the area under the serum concentratione-time curve values of ginsenosides Rd, F2, Rg3, and CK were 8.20 ± 11.95 ng·h/mL, 4.54 ± 3.70 ng·h/mL, 36.40 ± 19.68 ng·h/mL, and 40.30 ± 29.83 ng·h/mL, respectively. For the fermented red ginseng group, the the area under curve from zero to infinity (AUC) values of ginsenosides Rd, F2, Rg3, and CK were 187.90 ± 95.87 ng·h/mL, 30.24 ± 41.87 ng·h/mL, 28.68 ± 14.27 ng·h/mL, and 137.01 ± 96.16 ng·h/mL, respectively. The fecal CK-forming activities of the healthy volunteers were generally proportional to their ginsenoside Rd-eforming activities. The area under the serum concentration-time curve value of CK exhibited an obvious positive correlation (r = 0.566, p < 0.01) with the fecal CK-forming activity. Conclusion: The gut microbiota may play an important role in the bioavailability of the nonpolar RG ginsenosides by affecting the biotransformation of the ginsenosides.

THE CHANGES OF SERUM C-REACTIVE PROTEIN IN THE HEAD AND NECK INFECTION (두경부 감염 환자에서 혈청 내 C-Reactive Protein의 변화)

  • Lee, Ju-Hyun;Kim, Chin-Soo;Lee, Sang-Han;Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.29 no.1
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    • pp.5-13
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    • 2003
  • The purpose of this study is to determine the value of serum concentration of C-reactive protein(CRP) in comparison with ESR and leukocyte as the tools for diagnosis and follow-up study of infection. For this study, thirty-one patients with head and neck infection and thirty-two patients performed the orthognathic surgery were selected for experimental and control groups each other. we analyzed the blood sample daily to measure CRP, ESR and leukocytosis. The results of this study are as the following : 1. Serum C-Reactive Protein levels in the experimental group were higher than control group and the pattern of CRP changes continued to decline in both groups(P<0.001). 2. ESR changes in both groups were scattered without any special pattern. 3. Correlation between CRP and Leukocyte was higher than others(r=0.664, P<0.01). 4. In the Receiver Operating Characteristic(ROC) Curve of experimental group, rapid increase of CRP curve and Area under the curve(AUC) value, 0.774, indicate the high accuracy of estimation. 5. In experimental group, sensitivity of CRP, ESR, and Leukocytosis on recovery day were 83%, 17% and 71%. Based on the results of this study, we could conclude that determination of CRP is more useful method to diagnosis and follow-up study of infection than other commonly used variables in oral and maxillofacial region.

The Correlations of Parameters Using Contrast Enhanced Ultrasonography in the Evaluation of Prostate Cancer Angiogenesis (전립선암쥐모형의 신생혈관생성의 평가를 위해 시행된 역동적 조영 증강 초음파에서 얻은 변수간의 상관성연구)

  • Hwang, Sung Il;Lee, Hak Jong;Kim, Kil Joong;Chung, Jin-haeng;Jung, Hyun Sook;Jeon, Jong June
    • Ultrasonography
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    • v.32 no.2
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    • pp.132-142
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    • 2013
  • Purpose: The purpose of this study is to investigate the correlations of various kinetic parameters derived from the time intensity curve in a xenograft mouse model injected with a prostate cancer model (PC-3 and LNCaP) using an ultrasound contrast agent with histopathologic parameters. Materials and Methods: Twenty nude mice were injected with human prostate cancer cells (15 PC-3 and five LNCaP) on their hind limbs. A bolus of $500{\mu}L$ ($1{\times}10^8$ microbubbles) of second-generation US contrast agent (SonoVue) was injected into the retroorbital vein. The region of interest was drawn over the entire tumor. The time intensity curve was acquired and then fitted to a gamma variate function. The maximal intensity (A), time to peak (Tp), maximal wash-in rate (washin), washout rate (washout), area under the curve up to 50 sec ($AUC_{50}$), area under the ascending slope ($AUC_{in}$), and area under the descending slope ($AUC_{out}$) were derived from the parameters of the gamma variate fit. Immunohistochemical staining for VEGF and CD31 was performed. Tumor volume, the area percentage of VEGF stained in a field, and the count of CD31 (microvessel density, MVD) positive vessels showed correlation with the parameters from the time intensity curve. Results: No significant differences were observed between the kinetic and histopathological parameters from each group. MVD showed positive correlation with A (r=0.625, p=0.003), washin (r=0.462, p=0.040), $AUC_{50}$ (r=0.604, p=0.005), and $AUC_{out}$ (r=0.587, p=0.007). Positive correlations were also observed between tumor volume and $AUC_{50}$ (r=0.481, p=0.032), washin (r=0.662, p=0.001), and $AUC_{out}$ (r=0.547, p=0.012). Washout showed negative correlations with MVD (r=-0.454, p=0.044) and tumor volume (r=-0.464, p=0.039). The area percentage of VEGF did not show any correlation with calculated data from the curve. Conclusion: MVD showed correlations with several of the kinetic parameters. CEUS has the potential for prediction of tumor vascularity in a prostate cancer animal model.

A Comparative Study of Fuzzy Relationship and ANN for Landslide Susceptibility in Pohang Area (퍼지관계 기법과 인공신경망 기법을 이용한 포항지역의 산사태 취약성 예측 기법 비교 연구)

  • Kim, Jin Yeob;Park, Hyuck Jin
    • Economic and Environmental Geology
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    • v.46 no.4
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    • pp.301-312
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    • 2013
  • Landslides are caused by complex interaction among a large number of interrelated factors such as topography, geology, forest and soils. In this study, a comparative study was carried out using fuzzy relationship method and artificial neural network to evaluate landslide susceptibility. For landslide susceptibility mapping, maps of the landslide occurrence locations, slope angle, aspect, curvature, lithology, soil drainage, soil depth, soil texture, forest type, forest age, forest diameter and forest density were constructed from the spatial data sets. In fuzzy relation analysis, the membership values for each category of thematic layers have been determined using the cosine amplitude method. Then the integration of different thematic layers to produce landslide susceptibility map was performed by Cartesian product operation. In artificial neural network analysis, the relative weight values for causative factors were determined by back propagation algorithm. Landslide susceptibility maps prepared by two approaches were validated by ROC(Receiver Operating Characteristic) curve and AUC(Area Under the Curve). Based on the validation results, both approaches show excellent performance to predict the landslide susceptibility but the performance of the artificial neural network was superior in this study area.

A Estimation Technique of Typical Day for Solar Energy System Design (태양에너지 시스템 설계를 위한 Typical Day 예측기법)

  • Jo, Dok-Ki;Yun, Chang-Yeol;Kim, Kwang-Deuk;Kang, Young-Heak
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.409-412
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    • 2009
  • In this research, the intensity of solar energy, which was injected to the different angle plane every hour day by day, was technically documented and quantitatively analyzed through actual observations. In order to group every days into days with similar intensity, graph was drawn with respect to time for every day and each area value under the curve was calculated. Then, the search for grouped days having similar intensity curve patterns was carried out and the optimum incident angle of absorber plate was derived to maximize the efficiency of solar energy systems.

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Prediction of Fracture Energy of Concrete

  • Oh, Byung-Hwan;Jang, Seung-Yup;Byun, Hyung-Kyun
    • KCI Concrete Journal
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    • v.11 no.3
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    • pp.211-221
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    • 1999
  • A method to determine the fracture energy of concrete is investigated. The fracture energy may be calculated from the area under the complete load-deflection curve which can be obtained from a stable three-point bend test. Several series of concrete beams have been tested. The Present experimental study indicates that the fracture energy decreases as the initial notch-to-beam depth ratio increases Some problems to be observed to employ the three-point bend method are discussed. The appropriate ratio of initial notch-to-beam depth to determine the fracture energy of concrete is found to be 0.5. It is also found that the influence of the self-weight of a beam to the fracture energy is very small A simple and accurate formula to predict the fracture energy of concrete is proposed.

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Pharmacokinetics of Sulfamethoxazole in Rabbits with Experimental Renal Failure (실험적 신장장해 가토에서 설파메톡사졸의 약물동태학적 연구)

  • Choi, Jun-Shik;Lee, Chong-Ki
    • Journal of Pharmaceutical Investigation
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    • v.16 no.4
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    • pp.152-157
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    • 1986
  • The pharmacokinetics of sulfamethoxazole were investigated in rabbits with folate-induced renal failure. The blood level, area under the blood concentration curve (AUC) and biological half-life were increased significantly, and the urinary excretion was decreased significantly compared with those of normal rabbits. Correlation of serum creatinine concentration and AUC, biological half-life, and correlation of creatinine clearance and renal clearance have linear relationship respectively. From these results, dosage regimen of sulfamethoxazole is considered to be adjusted for effective and safe therapy in renal failure.

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Drug Interaction of Probenecid and Lithium Carbonate (프로베네시드와 탄산리튬의 약물상호작용)

  • Lee, Jin-Hwan;Lee, Chong-Ki
    • Journal of Pharmaceutical Investigation
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    • v.17 no.2
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    • pp.95-98
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    • 1987
  • The drug interaction between probenecid and lithium carbonate was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve (AUC) of lithium carbonate administered orally were elevated by coadministration of probenecid. Probenecid inhibited the urinary excretion of lithium carbonate in rabbits. Biological half-life and $t_{max}$ of lithium carbonate were prolonged by coadministration of probenecid. From these results, dosage regimen of lithium carbonate is considered to be adjusted for effective and safe therapy in the coadministration of probenecid.

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Drug Interaction of Nalidixic Acid and Probenecid in Rabbits (Nalidixic Acid와 Probenecid의 약물 상호 작용)

  • 최준식
    • YAKHAK HOEJI
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    • v.27 no.2
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    • pp.133-138
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    • 1983
  • The interaction between nalidixic acid and probenecid was studied pharmacokinetically in rabbits. The blood level and the area under the concentration curve(AUC) of nalidixic acid administered orally in dose of 100mg/kg was elevated by the coadministration of probenecid. Probenecid inhibited both the urinary excretion and the biliary excretion of nalidixic acid. Therefore, biological half-life of nalidixic acid was prolonged by the coadministrarion of probenecid. It was considered that the coadmini-stration of probenecid is more desirable than the single administration of nalidixic acid for the therapeutic effect.

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