• Journal of Wetlands Research
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• v.4 no.1
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• pp.43-50
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• 2002

The channel improvement plan has contributed to the flood damage reduction studies and the plan has mainly performed by the levee construction which creates the cut river. The cut river has mainly used as the agricultural and housing purposes. Recently, however, it is considered as a natural wetland for the purposes of a flood control and preservation of nature. So, this study compares the economical benefits according to the purposes of the cut river utilizations such as an agricultural, levee construction for flood damage reduction, and wetland. The study area is the downstream part of Kok-Neung stream which is a main tributary of Han river. The agricultural and levee construction benefits are estimated based on the 'Agricultural and Forestry Statistical Year' (2000) and the 'Standard for River Design' (2001). The benefit or value for the wetland utilization of the cut river is estimated by the enquete using questionnaire. As a results, for the case of which the cut river is used as an agricultural land, the present net benefit is estimated as 195.81 million won, for the levee construction, as 20853.00 million won and for the wetland, as 24692.89 million won. Therefore, the wetland is the best choice for the cut river utilization.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.370-375
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• 2011

In this paper, as a follow-up PRT studies of "J. Lee & K. Kim[2]", in terms of public transportation systems, economic feasibility of PRT systems was investigated. Based on previous studies, PRT demand was estimated and the required number of PRT vehicles has been calculated and the benefit was estimated. To ensure the economic feasibility, construction cost of a PRT system should be the level of 8 billion won per km, and the annual operating costs of the PRT system construction should be approximately 4.63% level. As a result, how much to reduce PRT construction costs, depending on whether decisions are considered to be economically feasible. Thus, PRT technology development will be conducted by targeting the most lightweight and by minimizing the infrastructure and vehicles of PRT.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.145-154
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• 2003

By optimizing the radiation protection the collective dose and individual dose could be reduced during YGN #4 $5^{th}$ outage in 2001. The collective doses for the two high radiation jobs decreased to 85% and 65% of expected doses. The proportion of workers with low dose (below 1mSv) exposure increased 4% while the proportion of workers with over 3mSv and 5mSv exposure are decreased to 2%, 1% respectively. But none is exposed over 8mSv for the annual dose. To aid decision of utilizing the robot, cost- benefit analysis was performed and reasonable point was proposed to use the robot. For the first time job, repeated ALARA meeting and mock up training were implemented to set up working procedure by identifying the trouble. To easily set up standard procedure, mockup process was videotaped and reviewed during ALARA meeting. Monitoring is a good approach to chase radiological working condition such as working time, dose rate. behavior of workers, especially for high radiation work. Those data were estimated and adjusted from the stage of work planning to mock up. At the stage of actual work the monitoring data were compared to the estimation and recorded to database. This database will not only be used as a powerful tool for dose optimization at the following outage but also as a guideline to dose constraint set up for optimization for each specific situation.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1315-1331
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• 2014

Replacement rates which shows the ratio of retirement income relative to preretirement income is used for a valuable evaluation measures while discussing social security benefit levels or the adequacy of retirement income. However, replacement rates has been only used for an index for evaluating benefit level at the time of retirement or specific retirement period in advanced research projects. This article analyzes how much the uncertainty of survival has an influence on retirement income, and shows replacement rates in conformity with the period of survival as an index. The researchers named this index lifetime income replacement rates. Analysis based on this index shows both life replacement income rates of 38.3% in men's case and of 41.1% in women's case while enrolled for 20years in three pension plans - national pension, retirement pension and individual annuity.

• Journal of Korean Society of Rural Planning
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• v.18 no.3
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• pp.25-41
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• 2012

The purpose of this study is to quantitatively analyze the social welfare value given to the designated rural settlement zone by the resident-participated site unit plan that the City of Cheongju is newly attempting to draft. Firstly, the costs and benefits from the site unit planning were estimated. Secondly, through literature review especially focussed on the benefit and cost estimation, on-site questionnaire was designed, and then sample residents of the qualifying sites were asked about their willingness to pay, which could make it possible to estimate the monetary value of its benefits by the contingent valuation method (CVM). Finally, the present value of net benefits (PVNB) was estimated through the derived costs and benefits. As a result of analysis, firstly, the present value of net benefits (PVNB) was found to be 7,641 billion won, which indicated that the implementation of district-unit plan would be able to cause sufficient social welfare value for the effected residents. Secondly, in examining the result of individual average amount for willingness to pay through the CVM, the area that benefited the most was found to be the road improvement. Thirdly, as a result of sensitivity analysis, the parameter with the most effects was the discount rate, which suggested that, in carrying out public projects, excessive market interest rates would not be appropriate.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.48-59
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• 2013

Normally the benefits concerned in the feasibility study for highway constructions are travel time saving, vehicle operation cost, etc. which can be calculated using the simulation tool(EMME3). However, there must be extra benefits of driving amenity improvement that drivers can perceive through decreasing driving fatigue and improving driving comfortability. In this study, the definition of driving amenity was established and a method of estimation for the benefit of driving amenity improvement was developed. Highway type (urban/rural highway) and highway density was considered to estimate the driving amenity. And Double-bounded Dichotomous Choice among Contingent Valuation Method(CVM) was applied to survey the willingness-to-pay of drivers when highway density decreases. Finally the value of driving amenity was estimated using the results of survey and logit medel. As the existing highway density is high, willingness-to-pay increases in both urban and rural highways. Even though the changing rates of highway density are same, willingness-to-pay is different based on the existing highway density.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.619-644
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• 2022

The purpose of this study is to estimate the economic benefit of improving ground water quality in Jeju Island, where groundwater pollution has recently become a social issue and various water quality improvement projects are being promoted. By applying the contingent valuation method, an online survey was conducted on Jeju Island residents to analyze the response data of 542 respondents and estimate the mean willingness to pay using 16 models. The estimation of the double-bounded dichotomous choice model confirmed that each household was willing to pay 28,008 won per year, with the willingness to pay estimated at a minimum of 17,762 won and a maximum of 37,416 won based on different models. The total annual benefit for Jeju Island's ground water quality improvement was estimated to be about 8.66 billion won , and socioeconomic factors influencing willingness-to-pay were investigated. This study is expected to serve as a foundation for the development of environmental improvement policies by assisting in the understanding of Jeju Island's unique water resource environment.

• Korean Journal of School Psychology
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• v.17 no.3
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• pp.263-286
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• 2020

The purpose of this study was to explore how overly positive self-estimations in peer relationships relate to subjective well-being and to the occurrence of interpersonal behaviors supporting basic psychological needs among elementary school students. This study tested the optimal margin hypothesis of positive illusion by examining the curvilinear relationship between these variables. The sample consisted of 346 fifth and sixth grade students. The self-criterion residual method was used to derive self-estimation bias scores by regressing the real peer relations index (i.e., In-degree) on their perceived peer relationship qualities. The results showed that girls more strongly overestimated the quality of their peer relationships than boys. Self-estimation biases had a positive curvilinear relationship with negative affects and a negative curvilinear relationship with relatedness needs supporting interpersonal behaviors. These results supported the existence of the optimal margin of positive illusion because overestimations of the quality of peer relationships were associated with lower levels of negative affects and relatedness needs-supporting interpersonal behaviors, though these benefits flattened out and no further benefit was observed after an optimal level of overestimation. However, self-estimation bias was linearly associated with positive affect, autonomy needs-supporting interpersonal behaviors, and competence needs-supporting interpersonal behaviors. These results indicated that optimal margin hypothesis was not supported for all outcome variables.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.27-41
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• 2019

To analyze the effectiveness of the safety e-reporting system, the present study carried out analysis of safety e-reporting data reported between September 2014 and July 2019, and selected items for measuring the effectiveness of safety e-reporting. Using these items, the effects of adopting the reporting system for the four major parking violations was analyzed, alongside an analysis of effects in terms of traffic accidents using the unit model. When we count the securement of the tax revenue through measures such as charging fines as the beneficial factor per case, the estimation of the benefit is around 62,000 KRW per case. Summing the two factors up, the total value of citizen's reports pertaining to the big four parking violations is about 275,000 KRW per case. Most of the reports made through the Safety e-Report system are about traffic and facilities. When we calculate the total annual benefit with the representative reporting value defined with traffic and facilities, the system received a total of 1,164,439 cases from 2014 to 2019, while citizens reported 52,721 cases for the big four parking violations from April to July 2019. As the value of a safety report is around the net benefit for last five years is around 27,340,000,000 KRW.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.133-141
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• 2009

For economic impact analysis on a R&D project of high-yield groundwater development in Jeju conducted by KIGAM from 2004 to 2007, benefit/cost ratio(BCR), net present value(NPV), and internal rate of return(IRR) were calculated by contingent valuation method(CVM), production function analysis, domestic water market analysis and technology factor analysis. Measurable direct impact parameters among the major outputs of this R&D project consisted the estimation 4 high-yield and high mineral groundwater reserve in Jeju. Annual use of the reserve by piped water and bottled water was estimated as 12.23 million ton and its monetary value was calculated as 293.4 million dollar in 2006 year value applied of 5.5% discount rate. Economic impact of this R&D project in NPV of year 2006, with applying a discount rate of 5.5%, was identified and estimated as 13.66 million dollar in NPV, 4.05 points in BCR, and 22.74% in IRR, respectively. Additional early launch benefit was 5.58 million dollar. Even increased of the 1% discount rate, NPV of this R&D project was also positive as 12.18 million dollar and BCR was 3.71.