• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 전문대학교육위원 P
• /
• pp.35-42
• /
• 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.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권1호
• /
• pp.347-352
• /
• 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.

• 한국지형학회지
• /
• 제27권2호
• /
• pp.65-80
• /
• 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.

• Computers and Concrete
• /
• 제10권1호
• /
• pp.35-47
• /
• 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
• /
• 제14권3호
• /
• pp.105-121
• /
• 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.

• 한국수학교육학회지시리즈E:수학교육논문집
• /
• 제24권1호
• /
• pp.177-193
• /
• 2010

본 연구는 고등학교 통계 영역의 확률분포에 제시되어 있는 정규분포를 이항분포에서 정규분포로의 근사, 정규분포곡선의 탐구, Monte Carlo 방법에 의한 정규분포곡선의 넓이 탐구, 정규분포곡선의 선형변환, 그리고 여러 형태의 정규분포곡선 탐구 등의 내용을 중심으로 CAS 계산기를 활용하여 탐구해보고자 한다. CAS 계산기의 도구적 기능인 사소화, 실험, 시각화, 집중의 측면에서 볼 때 지필로서는 교육과정에 제시된 확률분포의 목표를 달성하기 불가능하다고 판단된다. 따라서 본 연구에서는 CAS 계산기를 활용하여 정규분포곡선의 다양한 성질을 탐구하고 이러한 과정과 결과로부터 정규분포곡선에 대한 교수학적 시사점을 도출하고자 한다.

• Archives of Pharmacal Research
• /
• 제26권6호
• /
• pp.499-503
• /
• 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.

• 한국전산응용수학회:학술대회논문집
• /
• 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
• /
• pp.5.3-5
• /
• 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.

• 한국경영과학회지
• /
• 제22권4호
• /
• pp.183-219
• /
• 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
• /
• 제17권2호
• /
• pp.275-292
• /
• 2010

동일 환자에게 적용된 2가지 진단검사의 정확성을 비교하기 위한 방법들 중에서 두개의 ROC곡선 아래 면적(AUC; Area Under Curve)의 차이는 주요한 잣대 중 하나이다. 본 연구에서는 AUC의 차이를 추정하는 방법으로 비모수적방법, 최대가능도법, 일반화추축량에 의한 방법, 붓스트랩방법의 4가지를 포함확률(coverage probability), 기대길이 (expected length) 측면에서 모의실험을 통하여 비교하였다.