• Journal of Korea Water Resources Association
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• v.46 no.10
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• pp.989-995
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• 2013

This study attempts to estimate the benefits of environmentally-enhancing water ensuing from Sangkwan multi-purpose reservoir. To this end, we apply a survey technique, the contingent valuation (CV) method to elicit the public willingness to pay (WTP). Two CV surveys of randomly selected households were administrated to on-site and off-site areas. As it happens, a number of respondents reported zero WTPs for the environmentally- enhancing water. To deal with the zero WTPs, this study employs a spike model. The results show that average household's WTP for the environmentally-enhancing water ensuing from Sangkwan multi-purpose reservoir is estimated to be 1,393.7 won for on-site area and 2,237.7 won for off-site area per year. The benefits of environmentally-enhancing water ensuing from Sangkwan multi-purpose reservoir amount to about 38.3 billion won per year. Our findings are expected to contribute to determining an appropriate level of investment and making management policies with regard to the benefits of environmentally-enhancing water.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.541-547
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• 2013

It is important to establish water treatment technologies for drinking water because Korea belongs to water-stressed country. Leachate from recent incident of foot-and-mouth disease has become an opportunity to be aware of the need to manage water quality. Water purifiers are adopted to four or five steps of filtration process. Each steps are composed of a sediment filter, a pre-carbon filter, an UF or a RO membrane filter and a post-carbon filter. And additionally a ceramic filter can be used as a final stage. In this study, operational conditions in each steps are examined and characteristics of each filters are investigated. SEM analysis is used for filter surface and shape investigation using 6 commercial samples. Pore sizes of the sediment filter, the UF membrane filter, and the RO membrane filter are 30~47 ${\mu}m$, 0.005~0.5 ${\mu}m$, and 0.025~0.25 ${\mu}m$, respectively. Specific surface areas of activated carbons are ranged from 622 to 1,308 $m^2/g$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.329-343
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• 2004

Recently, our society has prominently raised the desire to well-being life since not only our economical situations are better than before, but environmental pollution become serious. In well-being trends, the natural or nature-related products are also issued on their usages as bio-/raw materials for our living industries, such as cosmetics, household goods, and so on. Especially, various materials which comes from medicinal plants has been discovered their physiological properties and validated their functions. Thus, they have been subjected to several processes, including extraction, isolation and concentration, and popularly introduced to cosmetic industry. In these reasons, a variety of cosmetic Products using natural materials has been developed, which are focused on whitening, wrinkle improvement, and anti-aging. In this report, we present a brief review of the function and classification of natural products interested in until now, and introduce the natural materials for cosmetics having physiological activities on skin, including Fructan, Acrea extract, Portulaca extract, Licorce extract, Dandelion extract, Ulmus extract, SC-glucan, Arbutin, and Sophora extract.

• Journal of dental hygiene science
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• v.20 no.1
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• pp.44-50
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• 2020

Background: Smartphones are a modern necessity. While they are convenient to use, smartphones also have side effects such as addiction. This study assessed the relationship between smartphone use, a part of everyday life in modern society, and oral health. Methods: An analysis was conducted using 2017 Korea Youth Risk Behavior Web-based Survey data. The propensity score estimation algorithm used logistic regression and 1:1 matching algorithm using nearest-neighbor matching. After matching, a total of 15,032 participants were classified into two groups containing 7,516 teenagers each who did and did not use smartphones, respectively. Results: Comparison of oral health behaviors according to smartphone use revealed a statistically significant difference in the frequency of tooth brushing per day, use of oral hygiene products, intake of foods harmful to oral health, and experience of oral health education (p<0.05). The factors affecting oral pain experience of adolescents were examined. Compared to male participants, female participants had an odds ratio of 1.627 for oral pain (p<0.05). According to the household income level, compared to the group with higher income, the group with lower income showed higher oral pain experience (p<0.05). Oral pain experience was 1.601 times more frequent among teenagers using smartphones (p<0.05). Conclusion: The results of this study indicated that use of smartphones by adolescents affected their oral health. These findings indicate the need for improved oral health management through the use of effective school oral health programs and individual counseling by oral health professionals, promotion of information dissemination through public media, and development of prevention strategies.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1031-1042
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• 2006

In recent years, a growing concern exists in watershed and stream improvement projects. Under these circumstances, this paper estimates monetary value of the attributes of alternatives for rehabilitation of hydrologic cycle using choice experiments. Choice experiments shows vivid image and estimates a willingness to pay based on their preference for environmental goods. A preliminary survey shows that the attributes of the Anyangcheon watershed are flood-damage possibilities, Instreamflow, water quality, river characteristic and estimates the tax for the Anyangcheon watershed improvements. We surveyed 200 citizens were selected as samples of watershed beneficing in Seoul and Gyeonggi Province and used conditional logit model to analyze the implicit values of the attributive per household. The benefit of the attributes by province based on the implicit price obtained from estimated parameters were calculated. This study is expected to contribute to the decision-making process for policy-makers by providing useful methodological framework and quantitative information related to watershed improvement projects.

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.29-37
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• 2012

This paper attempts to measure the economic benefits of tap water quality improvement using a specific case study of Ulsan, one of the large cities in Korea. To this end, we apply the contingent valuation (CV) method by employing a one-and-one-half bounded spike dichotomous choice question format. We surveyed a randomly selected sample of 400 households in Ulsan and asked respondents questions in person-toperson interviews about how they would willing to pay for the program. Respondents overall accepted the contingent market and were willing to contribute a significant amount (1,611 won), on average, per household per month. This willingness varies according to individual characteristics such as education level and income. The aggregate value of the program in Ulsan amounts to approximately 8 billion won per year.

• Journal of Korea Water Resources Association
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• v.41 no.3
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• pp.315-324
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• 2008

This paper double-bound dichotomous choice method as a contingent valuation methods is used to derive willingness to pay for the water quality at the Anyangcheon watershed. The linear random utility model show that value of improvement of the Anyangcheon watershed water quality is 4,930 won per house and month of the Seoul and Gyeong-gi area residents. There is no difference between Seoul and Gyeong-gi area residents. Respondents overall accepted the contingent market and were willing to contribute a significant amount (3,860 to 5,101 won), on average, per household per month. The aggregate value of the water quality improvement in the Anyangcheon watershed amounts to approximately 83.0 to 109.7 billion won per year. This study is expected to contribute to the decision-making process for policy-makers by providing useful methodological framework and quantitative information related to watershed improvement projects.

• Korean Journal of Health Education and Promotion
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• v.25 no.4
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• pp.43-54
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• 2008

Objectives: To identify the willingness of laypersons to perform the cardiopulmonary resuscitation(CPR), we analyzed their characteristics of socio-economic status and health-medical conditions associated with their willingness. Methods: Based on a health survey of Incheon Metropolitan City adults(N=5,114), tests of the differences between a group with willingness to perform CPR(=1,531) and a group with non-willingness to perform CPR(=3,583), and a logistic regression analysis of two groups were executed on socio-economic status-gender, age, marital stats, education level, jobs, and monthly household income-and health-medical conditions-CPR-related self-confidence, CPR education, chronic diseases, accident experience, EMS(emergency medical service) experience, and health status. Results: The rate of the willingness group was 29.9%, which was relatively lower than other developed countries. There were statistically significant differences between the willingness group with the non-willingness group on gender, age, jobs, CPR-related self-confidence, CPR education, and so on. Furthermore, Gender, age, students or armed forces among jobs, CPR-related self-confidence, and CPR education were statistically significant influential factors on the willingness to perform CPR. Conclusion: This study indicated that there was considerable variation in socio-economic status and health-medical conditions associated with willingness to perform CPR in Incheon. The CPR education aimed at increasing CPR-related self-confidence and correcting inaccurate perceptions of CPR attitudes would promote its use in response to out-of-hospital cardiac arrest.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.441-445
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• 2007

The mass housing supply policy of the government has resulted in the customer-centered market, and thereby the age of quality competition in the industry. In line with this trend of quality competition, therefore, this preliminary study aims to investigate the requirements of housing product planning to live up to the needs of customers in terms of quality, and thus analyze the types of quality differentiation of a housing product unit in our housing market. It turned out that many cases attempted differentiation in such ways as merely using luxurious finishing materials and instantly popular environment-friendly materials, and combining partial and limited household items with architectural elements of the facility system. The result of this study shows that the differentiation plan of housing product should be customer-centered, and therefore, focus on quality differentiation through organic combination of architecture-oriented plane and interior elements with technology-oriented facility and product elements. Hereby, in the future, housing product planning should include sustainable differentiation plans with reconsideration of concepts that customers have, and the needed procedure.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.164-171
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• 2015

Although coal-fired power generation has played a role as base load unit, it has incurred various social costs in the process of generating and providing electricity. It is necessary to extend the proportion of low-carbon power generations, and reduce the ratio of coal-fired power generation to cope with global climate changes. This study, therefore, attempts to estimate the public's willingness-to-pay (WTP) for substitution of supplied electricity from hydro-electricity generation, a representative renewable energy, for coal-fired power generation. To this end, we apply the contingent valuation (CV) method, widely used technique when valuing non-market goods, to elicit the public's WTP. In addition, a spike model is employed to consider zero WTPs. After the empirical analysis with 1,000 households CV survey data, the results show that mean household's WTP for replacing supplied electricity from hydro-electricity generation with coal-fired power generation is estimated to be about 54 KRW per kWh. The results of this study are expected to contribute to determining energy-mix and provide benefit information of hydro-electricity generation.