• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.347-352
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• 2016

Background: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) adenosquamous carcinoma data to identify predictive models and potential disparities in outcome. Materials and Methods: This study analyzed socio-economic, staging and treatment factors available in the SEER database for adenosquamous carcinoma. For the risk modeling, each factor was fitted by a generalized linear model to predict the cause specific survival. An area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. Results: A total of 20,712 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 54.2 (78.4) months. Some 2/3 of the patients were female. The mean (S.D.) age was 63 (13.8) years. SEER stage was the most predictive factor of outcome (ROC area of 0.71). 13.9% of the patients were un-staged and had risk of cause specific death of 61.3% that was higher than the 45.3% risk for the regional disease and lower than the 70.3% for metastatic disease. Sex, site, radiotherapy, and surgery had ROC areas of about 0.55-0.65. Rural residence and race contributed to socioeconomic disparity for treatment outcome. Radiotherapy was underused even with localized and regional stages when the intent was curative. This under use was most pronounced in older patients. Conclusions: Anatomic stage was predictive and useful in treatment selection. Under-staging may have contributed to poor outcome.

• Journal of The Geomorphological Association of Korea
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• v.27 no.2
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• pp.65-80
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• 2020

This paper deals with risk assessment of life in a landslide-prone area by a GIS-based modeling method. Landslide susceptibility maps can provide a probability of landslide prone areas to mitigate or proper control this problems and to take any development plan and disaster management. A landslide inventory map of the study area was prepared based on past historical information and aerial photography analysis. A total of 550 landslides have been counted at the whole study area. The extracted landslides were randomly selected and divided into two different groups, 50% of the landslides were used for model calibration and the other were used for validation purpose. Eleven causative factors (continuous and thematic) 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 hazard analysis. The correlation between landslides and these factors, pixels were divided into several classes and frequency ratio was also extracted. Eventually, a landslide susceptibility map was constructed using a logistic regression model based on entire events. Moreover, the landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract a success rate curve. Based on the results, logistic regression produced an 85.18% accuracy, so we believed that the model was reliable and acceptable for the landslide susceptibility analysis on the study area. In addition, for risk assessment, vulnerability scale were added for social thematic data layer. The study area predictive landslide affected pixels 2,000 and 5,000 were also calculated for making a probability table. In final calculation, the 2,000 predictive landslide affected pixels were assumed to run. The total population causalities were estimated as 7.75 person that was relatively close to the actual number published in Korean Annual Disaster Report, 2006.

• Proceedings of the KIEE Conference
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• 1999.11a
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• pp.35-42
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• 1999

As our power system has changed the past undeveloped model causing the lacked supply of power to the civilized model that the remained one makes the voltage and the frequency rise at the middle of the night, the leading power factor operation of generators, that is, the under-exited operation is essentially to be needed, so, at a viewpoint of the stability of the power system, it is a very important factor. In this investigation. the equation of curves for each area on the capability curve has been studied at the above-mentioned viewpoint. Also, each capability curve for the operating power stations (Nuclear P/S, Thermal P/S, Hydrolic & pumping-up P/S Gas turbine P/S) has, been presented, and studied whether the leading power factor operational area is able to be expanded or not.

• Computers and Concrete
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• v.10 no.1
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• pp.35-47
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• 2012

The ideal gradating curve is used in this study to estimate densified aggregate blended ratio and total surface area of aggregate, there by under assigned paste amount of concrete, and coating paste thickness can then be deduced. Four groups of concrete mixtures were prepared and the corresponding concrete properties, such as workability, compression strength, ultrasonic velocity, surface resistivity and chloride ion penetration, were measured and finally the results are interpreted in terms of "coating thickness". The result shows as the coating thickness of the concrete is higher than critical one, the coating thickness on aggregate does affect the workability, and whatever workability is required the superplasticizer can be adjusted to achieve the demand workability. Under a fixed paste quality at the same age, coating paste thickness is inversely proportional to the concrete properties, especially as the coating thickness gets thinner.

• Journal of Pharmaceutical Investigation
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• v.14 no.3
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• pp.105-121
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• 1984

The bioavailability of rifampicin (brand A, B and C) was studied and the dissolution by foamed plastic rotating method and basket rotating method was also investigated. The results were as follows; 1. In the case of foamed plastic rotating method, it was revealed that dissolution rate of brand C was most rapid, but in the case of basket rotating method the results revealed that brand B was most rapid. Also it was observed that the dissolution rate in artificial gastric juice was more rapid than one in artificial intestinal juice, and that Avicel added in capsule increased additively the dissolution rate, particulary brand B. 2. Relative systemic availability by urine data showed that the results from all capsules filled with brand A, B and C were identical but in the case of the ripamficin capsules filled with Avicel, the results showed that Avicel increased the availability of brand A and B. 3. Area under serum concentration curve $(0{\sim}8hrs)$ was in order of $brand\;A{\fallingdotseq}brand\;C$ > brand B, but Avicel increased significantly the AUC of brand B and showed no effect in others. 4. Relative systemic availability calculated with excreted amount of rifampicin in urine was similar in each rifampicin capsules. In rifampicin (A) and rifampicin (B), Avicel which added in capsules appeared increasing tendency in urine excretion of rifampicin, but in rifampicin (C) it did not appeared. 5. Area under serum concentration curve $(0{\sim}8hrs)$ in rifampicin capsules was in order of $rifampicin(A){\fallingdotseq}rifampicin(C)$>rifampicin(B). In rifampicin (B) with Avicel capsules, area under serum concentration curve (0-8hrs.) increased significantly and in others insignificantly.

• Communications of Mathematical Education
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• v.24 no.1
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• pp.177-193
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• 2010

The purpose of this study is to explore normal distribution in probability distributions of the area of statistics in high school mathematics. To do this these contents such as approximation of normal distribution from binomial distribution, investigation of normal distribution curve and the area under its curve through the method of Monte Carlo, linear transformations of normal distribution curve, and various types of normal distribution curves are explored with CAS calculator. It will not be ablt to be attained for the objectives suggested the area of probability distribution in a paper-and-pencil classroom environment from the perspectives of tools of CAS calculator such as trivialization, experimentation, visualization, and concentration. Thus, this study is to explore various properties of normal distribution curve with CAS calculator and derive from pedagogical implications of teaching and learning normal distribution curve.

• Archives of Pharmacal Research
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• v.26 no.6
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• pp.499-503
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• 2003

Because physiological changes that potentially alter pharmacokinetics occurs in diabetes mellitus patients, pharamacokinetics of drugs used in the treatment of hypertension was studied using acebutolol as a model anti-hypertensive drug. Thus, the pharmacokinetics of acebutolol was investigated after oral administration of acebutolol (15 mg/kg) to control rabbits and rabbits with acute or chronic diabetes mellitus induced by alloxan. Kidney and liver functions were documented for acute and chronic diabetes mellitus groups based on plasma chemistry data. After oral administration of acebutolol to acute and chronic groups, the plasma concentrations appeared higher; As a result, area under the plasma concentration-time curve from time zero to time infinity10575 and 8668 $\mu g\cdot$ h/mL for acute and chronic group, respectively. In comparison, the area was apparently smaller in the control group (i.e., 7132 $\mu g\cdot$ h/mL). The half-life in acute groups was significantly prolonged 8.45 h compared with the half-life in the control group (i.e., 6.30 h). Alteration in acebutolol pharmacokinetics was more pronounced in the acute group as evidenced by the significantly higher values the area under the plasma concentration time curve, absorption rate constant and maximum plasma concentration compared with chronic or control group. Therefore, these observations indicate that acebutolol pharmacokinetics may be affected in patients with diabetes mellitus, especially in the early stage of the disease.

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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• 2003.09a
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• pp.5.3-5
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• 2003

The boundary of a typical period-2 component in the degree-3 bifurcation set is formulated by a parametrization of its image which is the unit circle under the multiplier map, Some properties on the geometry of the boundary are investigated including the root point, the cusp, the component center and the length as well as the area bounded by the boundary curve. An algorithm drawing the boundary curve with Mathematica codes is proposed and its implementation exhibits a good agreement with the analysis presented here.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.4
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• pp.183-219
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• 1997

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 dary and each area value under the curve was calculated. Then, the search for grouped days having similar intensity curve patterns was carried out. In order to maximize the efficiency of solar energy systems, the optimum incident angle of absorber plate was derived.

• Communications for Statistical Applications and Methods
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• v.17 no.2
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• pp.275-292
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• 2010

Receiver operating characteristic(ROC) curves can be used to assess the accuracy of tests measured on ordinal or continuous scales. The most commonly used measure for the overall diagnostic accuracy of diagnostic tests is the area under the ROC curve(AUC). When two ROC curves are constructed based on two tests performed on the same individuals, statistical analysis on differences between AUCs must take into account the correlated nature of the data. This article focuses on confidence interval estimation of the difference between paired AUCs. We compare nonparametric, maximum likelihood, bootstrap and generalized pivotal quantity methods, and conduct a monte carlo simulation to investigate the probability coverage and expected length of the four methods.