• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.3
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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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• v.8 no.3
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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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• 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.

• 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.

• Earthquakes and Structures
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• v.19 no.4
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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.

• Water for future
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• v.10 no.1
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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.

• Journal of The Geomorphological Association of Korea
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• v.24 no.3
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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.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.597-611
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• 2013

This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.557-564
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• 1996

Based on stem analysis as well as branch analysis data of each tree from 8 plots of circle clear-cutting and 1 biomass plot in Changbai Mountain area, located in Northeast of China, the effective crown form of Changbai larch(Larix olgensis H.) plantation were studied by using the approach of crown curve. The results indicated that the cross-section forms of effective crown were stable and showed approximate circle for different tree size. Because the effective crown was on upper position of the canopy and its form reflects crown architecture under non-competition condition, the architecture is mainly affected by species hereditary feature. Therefore, for the specified species the effective crown form was thought to be relatively stable. The effective crown form of tree was neither related to the tree size within stand nor to the stand condition for different stand. The total effective crown curve of larch plantation could be characterized by using mean effective crown taper.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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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.