• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 추계학술대회 논문집
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• pp.163-164
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• 2007

• Journal of the Korean Data and Information Science Society
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• 제28권5호
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• pp.1167-1177
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• 2017

The censored regression using the pseudo-response variable proposed by Buckley and James has been one of the most well-known models. Recently, the varying coefficient regression model has received a great deal of attention as an important tool for modeling. In this paper we propose a censored varying coefficient regression model using Buckley-James method to consider situations where the regression coefficients of the model are not constant but change as the smoothing variables change. By using the formulation of least squares support vector machine (LS-SVM), the coefficient estimators of the proposed model can be easily obtained from simple linear equations. Furthermore, a generalized cross validation function can be easily derived. In this paper, we evaluated the proposed method and demonstrated the adequacy through simulate data sets and real data sets.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1139-1143
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• 2009

Pneumatic cylinder is widely used as key component of various industry fields just like automation production line. Recently, people begin to pay attention to reduce development period and cost of pneumatic cylinder so research requirements of accelerated life test of pneumatic cylinder have been increased more than ever. In this research, we shall evaluate availability of acceleration model by statistical analysis of acceleration model's predicted value and life data which acquired in a real operation condition after finish accelerated life test of pneumatic cylinder. Also to predict the life of pneumatic cylinder in the operation condition we shall develop new acceleration model equations.

• 환경영향평가
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• 제22권6호
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• pp.695-703
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• 2013

Soil erosion and sediment delivery ratio(SDR) were estimated by using HSPF model in 3 tributaries of upper stream of Geum river-basin. Meteorological data and other input data were constructed from 2006 to 2011 year by the HSPF model. Flow and suspended solid results were relatively matched with the measurement data through the calibration and validation of the model. Soil erosion was proportional to the amount of rainfall and the area of watershed based on the results of model calibration and validation. SDR in Moojunamdea stream was the highest and one in Cho stream was the lowest. This was effected by the geographical characteristic. SDR was 17.6% Moojunamdea stream, 9.1% Cho stream and 13.2 % Bocheong stream. As the SDR was effected by watershed area and shape factor in this study area.

• 한국농공학회논문집
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• 제51권4호
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• pp.15-20
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• 2009

The purpose of this study was to test the applicability of the HSPEXP model performance criteria for calibrating hydrologic parameters of HSPF. Baran watershed, located at Whasung city, was selected as a study watershed in this study. Input data for the HSPF model were obtained from the digital elevation map, landuse map, soil map and others. Water flow data from 1996 to 2000 was used for calibration and from 2002 to 2007 was for validation. Using the HSPEXP decision-support software, hydrology parameters were adjusted based on total volume, then low flows, storm flows, and finally seasonal flows. Suggested criteria for each model performance variables were referenced from the previous research. For the calibration period, all the HSPEXP model performance criteria were satisfied while two criteria were slightly violated for the validation period.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1419-1427
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• 2008

This paper shows the kernel Poisson regression which can be applied in the claims reserving, where the row effect is assumed to be a nonlinear function of the row index. The paper concentrates on the chain-ladder technique, within the framework of the chain-ladder linear model. It is shown that the proposed method can provide better reserve estimates than the Poisson model. The cross validation function is introduced to choose optimal hyper-parameters in the procedure. Experimental results are then presented which indicate the performance of the proposed model.

• 대한산업공학회지
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• 제30권1호
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• pp.58-64
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• 2004

In order to determine the level of safety on highway driving, the relationship between the psychophysiological signal and driving condition was investigated. In particular, a Demand-Effort model was conceptualized and used in this study to diagnose the suitability of driving by reading the patterns of psychophysiological signals. To run the model, threshold values were determined to categorize the high, moderate and low level of effort. To examine the sensitivity of the model, a cross-validation process was performed by collecting additional data. Further investigation need to be conducted to improve the sensitivity of the model for practical application.

• 대한전기학회논문지:전력기술부문A
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• 제48권4호
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• pp.428-433
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• 1999

The errors of IMU(Inertial Measurement Unit) can be divided into deterministic and random errors. Since the required accuracy of the IMU is very high, the errors must be compensated by using an accurate error mode. In this paper, we present a method to get a more accurate error model in a laboratory test. This was done by considering the setting misalignment in the laboratory test in the IMU error model. We considered here the IMU which consits of DTG(dynamically tuned gyroscope) and pendulum type accelerometer. First, it was shown that the estimation result from the model which does not contain the setting misalignment gives considerable estimation error at the validation test. Second, a new model considering the setting misalignment was derived. Finally, by validation test using the estimation results from new model the validity of it was proved.

• Structural Engineering and Mechanics
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• 제15권1호
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• pp.1-19
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• 2003

This paper presents the formulation of a new bridge-vehicle system with validation using the field data. Both pitching and twisting modes of the vehicle are considered in the contribution of the dynamic effects in the bridge responses. A heavy vehicle was hired as a control vehicle with known axle weight, axle spacing and spring coefficients. The measured responses were generated from the control vehicle running at a particular speed at a test span at Ma Tau Wai Flyover. The measured responses were acquired using strain gauges installed beneath the girder beams of the test bridge. The simulated responses were generated using BRVEAN that is a self-developed program based on the proposed bridge-vehicle system. The validation shows that the bridge model is valid for representing the test bridge and the governing equations are valid for representing the motion of moving vehicles.

• Structural Monitoring and Maintenance
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• 제2권4호
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• pp.383-397
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• 2015

This article identifies and addresses current limitations on the use of numerical models for validation and/or calibration of damage detection methodologies that are based on the analysis of the high frequency response of the structure to identify the occurrence of abrupt anomalies. Distributed-plasticity non-linear fiber-based models in combination with experimental data from a full-scale reinforced concrete column test are used to point out current modeling techniques limitations. It was found that the numerical model was capable of reproducing the global and local response of the structure at a wide range of inelastic demands, including the occurrences of rebar ruptures. However, when abrupt sudden damage occurs, like rebar fracture, a high frequency pulse is detected in the accelerations recorded in the structure that the numerical model is incapable of reproducing. Since the occurrence of such pulse is fundamental on the detection of damage, it is proposed to add this effect to the simulated response before it is used for validation purposes.