• Journal of the Korean Statistical Society
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• v.27 no.1
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• pp.101-112
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• 1998

This paper is concerned with the asymptotic properties of the least absolute deviation estimators for the nonlinear regression model when dependent variables are subject to censoring time, and proposed the simple and practical sufficient conditions for the strong consistency and asymptotic normality of the least absolute deviation estimators in censored regression model. Some desirable asymptotic properties including the asymptotic relative efficiency of proposed model with respect to standard model are given.

• Journal of the Korean Data and Information Science Society
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• v.5 no.1
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• pp.59-66
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• 1994

Heller and Simonoff(1990) compared several methods of estimating the regression coefficient in a modified proportional hazards model, when the response variable is subject to censoring. We give another method of estimating the parameters in the model which also allows the dependent variable to be censored and the error distribution to be unspecified. The proposed method differs from that of Miller(1976) and that of Buckely and James(1979). We also obtain the variance estimator of the coefficient estimator and compare that with the Buckely-James Variance estimator studied by Hillis(1993).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.656-662
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• 2016

We have provided a variety of domestic construction technology related full-text services through the Construction Technology Digital Library system since 2001. CODIL is a system that services the database related to construction technology data. On the other hand, there is growing demand for DB every year, but the required budget is shrinking. Therefore, this study investigated the satisfaction to effectively service the construction technique-related full-text with a limited budget. The monetary value of full-text to express satisfaction with the quantified value was estimated using the Tobit model. The Tobit model is used as a contingent valuation method to estimate the value of non-market goods. This model is the limited dependent variable regression model to observations by censoring the limit of the left side or right side so that a biased outlier is not reflected in the willingness to pay. A survey was conducted by sampling 312 respondents. The mean, median, truncating the willingness of payment were calculated for the six types of the full-text services using the Tobit model. The statistically significant variables affecting the willingness to pay for the full-text services were identified. The mean value of per the full-text service was estimated to be 46,530 won. The significance of this study was to use the Tobit model to estimate the value of the construction technology-related full-text services for the first time in Korea.