• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권3호
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• pp.263-267
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• 2005

Building classifiers for financial real-world classification problems is often plagued by severely overlapping and highly skewed class distribution. New performance measures such as receiver operating characteristic (ROC) curve and area under ROC curve (AUC) have been recently introduced in evaluating and building classifiers for those kind of problems. They are, however, in-effective to evaluation of classifier's discrimination performance in a particular class of the classification problems that interests lie in only a local operating range of the classifier, In this paper, a new method is proposed that enables us to directly improve classifier's discrimination performance at a desired local operating range by defining and optimizing a partial area under ROC curve or domain-specific curve, which is difficult to achieve with conventional classification accuracy based learning methods. The effectiveness of the proposed approach is demonstrated in terms of fraud detection capability in a real-world fraud detection problem compared with the MSE-based approach.

• Current Optics and Photonics
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• 제8권3호
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• pp.282-299
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• 2024

Target detection (TD) is a research hotspot in the field of hyperspectral imaging (HSI). Traditional TD methods often mine targets from HSIs under a single imaging condition, without considering the influence of imaging conditions. In fact, the spectra of ground objects in HSIs are uncertain and affected by the imaging conditions (weather, atmospheric, light, time, and other angle conditions including zenith angle). Hyperspectral data changes under different imaging conditions. Therefore, the detection result for a single imaging condition cannot accurately reflect the effectiveness of the detection method used. It is necessary to analyze the performance of various detection methods under different imaging conditions, to find a more applicable detection method. In this paper, we study the performance of TD methods under various land-based imaging conditions. We first summarize classical TD methods and evaluation methods. Then, the detection effects under various imaging conditions are analyzed. Finally, the concepts of the stability coefficient (SC) and effective area under the curve (EAUC) are proposed to comprehensively evaluate the applicability of detection methods under land-based imaging conditions, in terms of both detection accuracy and stability. This is conducive to our selection of detection methods with better applicability in land-based contexts, to improve detection accuracy and stability.

• Journal of Pharmaceutical Investigation
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• 제17권2호
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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.

• Journal of Pharmaceutical Investigation
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• 제16권4호
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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.

• Earthquakes and Structures
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• 제19권4호
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• pp.287-301
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• 2020

Fragility as one of the most effective methods to evaluate seismic performance, which is greatly affected by damage index. Taking a multi span continuous rigid frame offshore bridge as an example. Based on fragility and reliability theory, considering coupling effect of time-varying durability damage of materials and time-varying attenuation effect of damage index to analyze seismic performance of offshore bridges. Results show that IDA curve considering time-varying damage index is obviously below that without considering; area enclosed by IDA of 1# pier and X-axis under No.1 earthquake considering this effect is 96% of that without considering. Area enclosed by damage index of 1# pier and X-axis under serious damage with considering time-varying damage index is 90% of that without considering in service period. Time-varying damage index has a greater impact on short pier when ground motion intensity is small, while it has a great impact on high pier when the intensity is large. The area enclosed by fragility of bridge system and X-axis under complete destruction considering time-varying damage index is 165% of that without considering when reach designed service life. Therefore, time-varying attenuation effect of damage index has a great impact on seismic performance of bridge in service period.

• 물과 미래
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• 제10권1호
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• pp.53-70
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• 1977

The analysis performed here is aimed to increase the familiarity of hydrologic process especially for the small basins which are densely gaged. Kyung An and Mu Shim river basins are selected as a representative basin according to the criteria which UNESCO has established back in 1964 and being operated under the auspice of Ministry of Construction. The data exerted from these basins is utilized for the determination of characteristics of procipitation and runoff phenomena for the small basin, which is considered as a typical Korean samall watershed. The study found that the areal distribution of preciptation did not show any significant deviation from the point rainfall. Since the area studied is less than 20 km#, the pointrainfall may be safely utilized as a representative value for the area. Also the effect of elevation on the precipitation has a minor significance in the small area where the elevation difference is less than 200m. The methodology developed by Soil Conservation Service for determination of runoff value from precipitation is applied to find the suitability of the method to Korean river basin. The soil cover complex number or runoff curve number was determined by comsidering the type of soil, soil cover, land use and other factors such as antecedent moisture content. The average values of CN for Kyung An and Mushim river basins were found to be 63.9 and 63.1 respectively under AMC II, however, values obtained from soil cover complex were less than those from total precipitation and effective precipitation about 10-30%. It may be worth to note that an attention has to be paid in application of SCS method to Korean river basin by adjusting 10-30% increase to the value obtained from soil cover complex. Finally, the design flood hydrograph was consturcted by employing unit hydrograph technique to the dimensionless mass curve. Also a stepwise multiple regression was performed to find the relationship between runoff and API, evapotranspiration rate, 5 days antecedentprecipitation and daily temperature.

• 한국지형학회지
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• 제24권3호
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• pp.105-118
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• 2017

The debris slope landforms which are existent in Korean mountains is generally on the steep slopes and mostly covered by vegetation, it is difficult to investigate the landform. Therefore a scientific method is required to come up with an effective field investigation plan. For this purpose, the use of Remote Sensing and GIS technologies for a spatial analysis is essential. This study has extracted the potential area of debrisslope landform formation using Fuzzy set and Bayesian Predictive Discriminate Model as mathematical data integration methods. The first step was to obtain information about debris locations and their related factors. This information was verified through field investigation and then used to build a database. In the second step, the map that zoning the study area based on the degree of debris formation possibility was generated using two modeling methods, and then cross validation technique was applied. In order to quantitatively analyze the accuracy of two modeling methods, the calculated potential rate of debrisformation within the study area was evaluated by plotting SRC(Success Rate Curve) and calculating AUC(Area Under the Curve). As a result, the prediction accuracy of Fuzzy set model wes 83.1% and Bayesian Predictive Discriminate Model wes 84.9%. It showed that two models are accurate and reliable and can contribute to efficient field investigation and debris landform management.

• 한국수자원학회논문집
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• 제46권6호
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• pp.597-611
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• 2013

본 연구에서는 Clark 모형의 시간-면적곡선의 구성 방법과 적용성을 검토하고 모멘트 원리에 의한 도달시간, 저류상수를 합리적으로 산정하기 위한 방법론을 고찰해 보았다. 격자 기반으로 폭 함수를 구성하고 운동과정을 순수 이류현상으로 가정하여 시간-면적곡선으로 사용하였다. 또한 도달시간과 저류상수는 모멘트 법의 원리에 따라 Clark 모형 구조에 적용하여 해석적으로 산정할 수 있는 방법을 제시하였다. 적용성 검토를 위해 (1) HEC-1에서 기본적으로 제공하는 좌우 대칭형상인 무차원 시간-면적곡선을 적용하고 매개변수 산정은 관측유출수문곡선과 계산된 유출수문곡선의 오차를 최소화하는 HEC-1의 최적화 기법 사용, (2) HEC-1에 폭 함수 기반의 시간-면적곡선을 적용하고 매개변수 산정은 HEC-1의 최적화 기법 사용, (3) 폭 함수 기반의 시간-면적곡선을 이용하여 모멘트 원리에 따라 매개변수를 직접 산정하는 방법을 적용하였다. 방법별로 산정된 Clark 모형의 매개변수들을 HEC-1을 이용하여 직접유출량을 산정하고 관측 직접유출량과 비교하여 얻은 결과는 다음과 같다. (1) 정량적으로 비교하기 위해 산정한 첨두유량과 첨두발생 시간의 상대오차 및 효율계수 E(Efficiency Coefficient)를 비교한 결과, 시간-면적곡선을 폭 함수로 대체하여 HEC-1으로부터 추정된 매개변수가 관측값을 잘 반영하였다. (2) Clark 모형의 올바른 적용을 위해서는 HEC-1에서 기본적으로 제공하는 좌우 대칭형상인 무차원 시간-면적곡선보다는 적용 대상유역의 배수구조가 적절하게 반영된 시간-면적곡선의 사용이 합리적일 것으로 판단된다. (3) 본 연구 방법은 첨두유량과 첨두시간의 상대오차 범위와 재현정도를 나타내는 효율계수를 비교하여 볼 때 대체로 양호하게 모의되었고, 대상유역별 유량측정성과인 하천평균유속과 비교했을 때 본 연구 방법이 다소 실제 유속에 접근하고 있음을 확인하였다. (4) 본 연구에서 모멘트 원리를 기반으로 제안한 매개변수 추정을 위한 방법은 유역의 이류현상과 저류현상을 정량적으로 계량할 수 있는 효율적인 관계식으로 사용할 수 있음을 확인하였다. (5) 본 방법에 의해 계산된 수문곡선이 대부분 관측수문곡선의 우측으로 왜곡되고 첨두유량은 과소평가 되는 것을 보이고 있다. 이것은 평균과 분산만을 고려하여 유역을 하나의 평균이송속도로 모의한 본 연구의 한계점으로 판단된다. 만약 모멘트의 왜곡도를 고려하고 유역을 지표면과 하천으로 나누어 평균이송속도를 모의한다면 물리적인 특성을 충분히 반영하여 매개변수를 추정 할 수 있을 것으로 판단된다.

• 한국산림과학회지
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• 제85권4호
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• pp.557-564
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• 1996

중국(中國) 북동부(北東部)에 소재한 장백산(長白山)지역에서 원형으로 개벌한 8개의 표준지와 1개의 biomass(생물질량(生物質量)) 표준지(標準地) 내에 존재하는 각 개별목(個別木)에 대해 가지를 포함한 수간(樹幹)을 분석한 자료로 수관곡선(樹冠曲線)에 대한 방법을 이용하여 장백낙엽송(長白落葉松)(Larix olgensis H.) 조림지에 있어 유효수관형(有效樹冠形)에 대한 연구를 실시하였다. 얻어진 결과에 의하면 유효수관(有效樹冠)의 횡단면형태(橫斷面形態)는 여러 입지(立地)에서 모두 일정하게 원형에 가까운 것으로 나타났다. 유효수관(有效樹冠)은 임관(林冠)의 상부에 존재해 있고 그 형태는 비경쟁(非競爭) 조건하에서의 수관구조(樹冠構造)를 반영하는 것이기 때문에, 그 구조는 주로 각 종(種)의 유전적(遺傳的) 특성에 의해 가장 큰 영향을 받는다. 따라서 특정한 종(種)들의 유효수관형(有效樹冠形)은 비교적 일정한 것으로 판명되었다. 임목(林木)의 유효수관형(有效樹冠形)은 같은 임분내의 임목의 크기와 관계가 없고 여러 임분(林分)들의 다양한 임분(林分)의 조건과도 관계가 없는 것으로 나타났다. 장백낙엽송(長白落葉松) 인공조림지(人工造林地)의 총(總) 유효(有效) 수관곡선(樹冠曲線)은 평균 유효수관(有效樹冠) 초살도(梢殺度)를 이용하여 그 특성을 파악할 수 있다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.395-400
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• 2005

The ship hull part is always exposed to severe corrosive environments. Therefore, it should be protected in appropriate ways to reduce corrosion problems. So there are two effective methods in order to protect the corrosion of ship hull. One is the paint coating as a barrier between steel and electrolyte (seawater) and the other is the cathodic protection(CP) supplying protection current. In the conventional design process of the cathodic protection system the required current densities of protected materials have been used. However, the anode position of field or laboratory experiment for obtaining the required current density for CP is significantly different from anode position for real structures. Therefore, the recent CP design must consider the optimum anode position for potential distribution equally over the ship hull. The CP design companies in the advanced countries can obtain the potential distribution results on the cathodic materials by using the computer analysis module. This study would show how to approach the potential analysis in the field of corrosion engineering. The computer program can predict the under protection area on the structure when the boundary condition and analysis procedure are reasonable. In this analysis the polarization curve is converted to the boundary condition in material data.