• Environmental and Resource Economics Review
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• v.20 no.1
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• pp.119-153
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• 2011

This study reviews various aspects of model formulating processes of dichotomous choice responses of the contingent valuation method (CVM), which has been increasingly used in the preliminary feasibility test of Korea public investment projects. The theoretical review emphasizes the consistency between WTP estimation process and WTP measurement process. The empirical analysis suggests that two common parametric models for dichotmous choice responses (RUM and RWTP) and two commonly used probability distributions of random components (probit and logit) resulted in all most the same empirical WTP distributions, as long as the WTP functions are specified to be a linear function of the bid amounts. However, the efficiency gain of DB response compared to SB response were supported on the ground that the two CV responses are derived from the same WTP distribution. Moreover for the exponential WTP function which guarantees the non-negative WTP measures, sample mean WTP were quite different from median WTP if the scale parameter of WTP function turned out to be large.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.163-180
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• 2009

This study attempts to investigate the preference uncertainty of respondents involved in stating their Willingness to Pay (WTP). For the Contingent Valuation Method (CVM) survey, we employed two approaches using two split samples. The respondents of one sample were given the opportunity to express intensity of preference through Multi-bounded Discrete Choice (MBDC) WTP questions, while those in the other sample were given Dichotomous Choice (DC) WTP questions. By incorporating the two elicited degrees of preference uncertainty into examining the WTP responses, we compared the two approaches. In comparing the DC model with the MBDC model, the mean WTP for the DC model was similar to PRYES in the MBDC Model. We concluded that the MBDC model estimates the various mean WTP while considering the preference uncertainty.

• Journal of the Korean Chemical Society
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• v.61 no.6
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• pp.339-345
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• 2017

Carbonaceous adsorbent (CA-WTP) was prepared by heat treatment at $400^{\circ}C$ for 2 h in N2 atmosphere using waste tire powder (WTP). WTP and CA-WTP were first characterized by thermo-gravimetric analysis (TGA), energy dispersive X-ray spectrometer (EDS), scanning electron microscopy (SEM), specific surface area analysis (BET) and FT-IR spectroscopy. Then, they were tested as adsorbents for removal of Cd in water. CA-WTP exhibited much higher specific surface area and total pore volume than WTP itself and showed higher adsorption capacity for Cd. Equilibrium data of adsorption were analyzed using Freundlich and Langmuir isotherm models. It was seen that both Freundlich and Langmuir isotherms have correlation coefficient $R^2$ value larger than 0.95. The results of studies indicate that CA-WTP developed from WTP by heat treatment could be used as efficient adsorbent for the removal Cd from water.

• Journal of Korean Society on Water Environment
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• v.38 no.6
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• pp.267-274
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• 2022

This paper is a result of research conducted on the 800,000 m³/d capacity of A Water Treatment Plant (WTP) and 400,000 m³/d capacity of B WTP plant in operation in the Nakdong River region. We evaluated the effect of algae broom on the WTP operation based on the running data of both WTP and the data on the pre-oxidation process field test for algae control using sodium permanganate (SPM) at the B WTP. The study results showed that during the algal bloom period, the coagulant dose increased by 102% in A WTP and 58% in B WTP, respectively, and the chlorine dose also increased by 38% and 29%, respectively, which may affect Total trihalomethane (THM) production. Data such as algal populations and Chl-a, residual chlorine and THM, algal populations, and ozone dose appeared also highly correlated, confirming that algal broom affects WTP operations, including water quality and chemical dosage. As a result of the field test of B WTP, THMs appeared lower than that of the control, suggesting the possibility of the SPM pre-oxidation process as an alternative to algae-related water quality management. Furthermore, in terms of GHG emissions due to energy consumption, it was observed that the pre-oxidation process using SPM was approximately 10.8%, which is a very low ratio compared to the pre-ozonation process. Therefore, these results suggest that the SPM pre-oxidation process can be recommended as an alternative to low-carbon water purification technology.

• Journal of KIISE:Information Networking
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• v.29 no.4
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• pp.447-458
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• 2002

In this paper, we design and implement Wireless Transaction Protocol(WTP) and evaluate it for wireless transaction processing in mobile computing environments. The design and implementation of WTP are based on the coroutine model that might be suitable for light-weight portable devices. We test the compatibility between our product and the other products such as Nokia, Kannel and WinWAP For the evaluation of WTP, we use an Internet simulator that can arbitrary generate random wireless errors based on the Gilbert model. In our experiment, the performance of WTP is measured and compared to those of Transmission Control Protocol(TCP) and TCP for Transactions. The experiment shows that WTP outperforms the other two protocols for wireless transaction processing in terms of throughput and delay. Especially, WTP shows much higher performance In ease of high error rate and high probability of burst errors. This comes from the fact that WTP uses a small number of packets to process a transaction compared to the other two protocols and introduces a fixed time interval for retransmission instead of the exponential backoff algorithm. The experiment also shows that the WTP performance is optimized when the retransmission counter is set to 5 or 6 in case of high burst error rate.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.157-165
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• 2016

To provide the baseline for pricing, this paper proposes pricing-by-rating (PBR) as pricing model at micro-foundations level that can work as the baseline for all pricing models as well as an assessment criterion of business model in all circumstances. It sets up firstly WTP (willingness to pay/purchase) model from explicit needs and develops PBR based on the ordinal scale of the difference between the WTP and the WTS (willingness to supply/sell) by comparing individually the corresponding element/component of a firm's actual marketing mix 4P with that of the best SPEC (solution, price indicator by WTP, encouragement, channel) as an ideal 4P a customer expects and also by comparing the interaction between the 4P and the best SPEC as a whole collectively. And through illustrations it shows its applicability to evaluating business model in practice and finally asserts that PBR works as the baseline for pricing policy and as a criterion of business model evaluation in any circumstances.

• Journal of Agricultural Extension & Community Development
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• v.20 no.3
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• pp.701-727
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• 2013

To estimate the WTP(Willingness to Pay) for consistent maintenance of rural multi-cultural families' contribution worth such as vitality of rural population, regional economic vitalization, cultural diversity of rural, maintenance of rural family society, and diversity of rural resource, a questionnaire survey was conducted by double-bounded dichotomous choice method based on Weibull model in 41 city county of rural. A estimation models based on Tunball models were developed and applied to WTP estimation with logistic analysis. WTP estimates for consistent maintenance of multi-cultural contribution worth by rural resident was 458 hundred million won. It means that each rural household can pay 13,840 won per annual. WTP estimates assessed by multi-cultural families' husband as a criteria for comparison was 502 hundred million won. It means that each household can pay 15,170 won per annual.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.2
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• pp.205-221
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• 2001

It will become more and more popular to use the long-term care facilities and home health care services with the chronic disease increasing. It depends on how much the consumers would pay and purchase the services. They might get more benefits from that kind of services than from ordinary hospitalization. So far, the study of determining the medical service price has focused most often on the efforts from the providers' view. But it must be reasonable to include the consumers' value for the service. This study was performed to assess WTP(Willingness to Pay) for home health care service in order to apply to the determination of nursing price in a reasonable manner. In this study, respondents were asked if they would pay for the service's intangible benefits under the four different types(open-ended minimum WTP, open-ended maximum WTP, bidding WTP, referendum WTP). The contingent valuation method is a potentially useful tool in understanding how people value the benefits of the service. As a result, average open-ended minimum WTP was W16,015 per day among 65 respondents. Average open-ended maximum WTP was W29,154 per day among 65 respondents. Average bidding WTP was W26,300 per day among 65 respondents. Average referendum WTP was W22,200 per day among 70 respondents. The results of regression analyses were also consistent with theoretical prediction, e.g., increasing WTP with consumers' value for the service, state of patients, and household income. This study demonstrated that it was more reasonable to consider the consumers' value in determining the services' price. In addition, a further study is needed to test the validity of this CV method and to determine a proper nursing price based on the consumers' view.

• Environmental and Resource Economics Review
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• v.20 no.4
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• pp.797-826
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• 2011

This study analyzed whether a spatial difference exists in the willingness to pay(WTP) for renewable electricity, by applying the contingent valuation method(CVM). Considering renewable portfolio standards(RPS) as the hypothetical market, we asked WTP in the form of the monthly electricity bills for using renewable electricity; the respondents were people living in Seoul, Ulsan, JeollaNamdo, and Gangwondo. Our empirical results showed that the mean WTP of Gangwondo was the highest, and that of JeollaNamdo, the lowest. The hypothesis that the WTP of the entire sample would not differ from that of the individual regions was rejected. Hence, a spatial difference probably exists in the WTP for electricity from renewable energy. Further, we attributed the spatial differences in WTP to the experience of those staying near the renewable energy facility and the acceptability of the facility.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.37-43
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• 2006

Recently, needs for reuse of sludge produced from WTP(water treatment plant) have been increased with shortage of landfill sites and difficulties of the treatment and disposal processes. Therefore, Reusing is becoming an Increasingly popular waste management alternative to divert waste from landfills. In order to research the characteristics of WTP sludges, we used the sludges of C WTP which intake the lake Dae-Cheong and the sludges of S WTP which intake Keum river, The specific surface area of C and S WTP sludges were $0.9986m^2/cc\;and\;1.874m^2/cc$, respectively. The gravity was about $2.0{\sim}2.4$ which are scope of peat or loamy clay. The major minerals of C WTP sludges were kaolinite(48.4%), muscovite(19.5%), and quartz(16.7%). Also, muscovite(31.6%), quartz(30.3%), and kaolinite(17.3%) in S WTP sludges were major minerals.