• Environmental and Resource Economics Review
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• v.25 no.1
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• pp.1-25
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• 2016

This study investigated the variability of WTP estimates(i.e. mean or median) with ad hoc assumptions of specific parametric probability distributions(i.e. normal, logistic, lognormal, and exponential distribution) to estimate WTP function using dichotomous choice CV data on mortality risk reduction. From the perspective of policy decision, the variability of these WTP estimates are intolerable in comparison with those of Turnbull nonparametric estimation method which is free from ad hoc distribution assumptions. The Turnbull nonparametric estimation can avoid a kind of misspecification bias due to ad hoc assumption of specific parametric distributions. Furthermore, the WTP estimates by Turnbull nonparametric estimation are robust because the similar estimates are elicited from a dichotomous choice or double dichotomous choice CV data, and the statistically significant WTP estimates can be obtained even though it is not possible by parametric estimation methods. If there are considerable variability among those WTP estimates by parametric estimation methods in condition with no criteria of model adequacy, the mean WTPs from Turnbull nonparametric estimation can be the robust estimates without ad hoc assumptions, which can avoid controversial issues in the perspective of policy decisions.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.2
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• pp.39-49
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• 2002

The purpose of this study is to propose an objective and rational methodology for the selection of proposed sites far the National Trust(NT), which is the new alterative proposal far the conservation of natural environments destroyed by injudicious land development and economic growth. That is to enforce many analysis for the effective estimation of rare ecological and landscape resources and to propose a model based on estimation and united indicators. Using the estimative model, we apply it to the selection of the proposed site in micro scale and simultaneously offer the basic methodology of effective and systematic land conservation in macro scale. The results of this study are as follows: 1) The results of analysis for the reliability of estimative items and indicators, presented no problem in that the coefficient of reliability was over 0.7. 2) The correlation measure of the estimative indicator indicated that 'succession'and 'regenerating restorability' were highly correlative in the item of plants. Another three items showed a tendency to be alike. 3) The results of factor analysis on the characteristics of indicators, classified plants into four categories including a stable factor. The item of animals was classified as a stable and rare factor. The item of landscape was classified as a physical and mental factor and the environment as a pollutional and conditional factor. 4) The model of estimation created through factor analysis was valid for the approval of the regression model because significant probability was 0.00. When we consider the NT proposed site as a complex body that is composed of diverse natural and manmade resources, certainly the synthetic methodology of estimation is needed. If these studies are carried out, NT sites will be selected more rationally and effectively than at present. Consequently, they have the potential to play a core role of natural ecosystem conservation in Korea.

• The Pure and Applied Mathematics
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• v.30 no.2
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• pp.191-201
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• 2023

In this paper the control system described by Urysohn type integral equation is studied. It is assumed that control functions are integrally constrained. The trajectory of the system is defined as multivariable continuous function which satisfies the system's equation everywhere. It is shown that the set of trajectories is Lipschitz continuous with respect to the parameter which characterizes the bound of the control resource. An upper estimation for the diameter of the set of trajectories is obtained. The robustness of the trajectories with respect to the fast consumption of the remaining control resource is discussed. It is proved that every trajectory can be approximated by the trajectory obtained by full consumption of the control resource.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.117-118
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• 2005

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.511-512
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• 2007

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.502-503
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• 2008

• Environmental and Resource Economics Review
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• v.13 no.4
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• pp.685-715
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• 2004

This study applies two-choice model to identify the major determinants of NIMBY attitudes when a large-scale composting facility is built around a residential area. Using a survey data of residents in Jeju City, Korea, logit estimation is implemented. The empirical results are consistent with the implication of the specified model: a representative resident's NIMBY attitude is positively (negatively) affected by "Negative Neighborhood Characteristic Variables" ("Positive Wealth Attribute variables"). Socio-demographic variables may be summarized as mostly statistically insignificant, which implies that policy makers may have to take into consideration their region-specific socio-demographic factors instead of simply emulating the policies which have been successful elsewhere.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.943-964
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• 2005

This study estimated a wide range of stochastic process models using the frameworks of CKLS (1992) and Nowman and Wang (2001). For empirical analysis, the GMM estimation procedure is adopted for the monthly Brent crude oil prices from January 1996 to January 2005. Using the simulated price series, European call option premiums were calculated and compared each other. The empirical results suggest that the crude oil price has a strong dependency of volatility on the price level. Contrary to the results of previous related studies, it shows a weak tendency of mean reversion. In addition, the models provide different implications for pricing derivatives on crude oil.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.83-98
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• 2007

The handover between different radio access networks, especially where their coverage overlaps, suffers various complications since the different access networks provide different service characteristics. One way to reduce service interruptions and QoS (i.e., bandwidth, throughput, delay) degradations during the inter-technology handover is to reserve the required resource in advance. The resource reservation algorithm should minimize the handover latency and maximize the resource utilization based on the accurate estimation on mobile's location, velocity, movement pattern and service requirements. In this paper, we propose a resource reservation algorithm based on the mobile terminal velocity and the cell selection probability, which maximizes resource utilization ana reduces network overhead. We compare the proposed algorithm with PMS(Predictive Mobility Support) and VCDS(Velocity and Call Duration Support scheme) based on 3-layer network model under various scenarios.

• Journal of Korean Academy of Nursing Administration
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• v.9 no.2
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• pp.205-216
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• 2003

Purpose : This study wad aimed to estimate nursing cost for hemodialysis of secondary hospitals using Resource Based Relative Value Scale(RVRBS). Method : The first, calculated nursing workload for the hemodialysis of secondary hospitals. Second, measured each spent time according to 14 nursing behaviors. Third, computed Resource Based Relative Value(RBRV) scores and nursing expenses of hemodialysis nurse. Finally, estimated nursing cost for hemodialysis of secondary hospitals, Result & Conclusion : The mean RBRV scores for each nursing behaviors were from 218.9 to 383.9 point(mean=312.7). The high RBRV socres were 383.9(Complication during hemodialysis), 353.7(Access patient vascular), 345.7 (Patient Teaching). Nursing cost for hemodialysis was estimated 23,234(won).