• Journal of Korea Water Resources Association
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• v.56 no.3
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• pp.225-233
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• 2023

Urban rivers and their surrounding environments have been altered due to factors such as rapid economic growth and urban development. This alteration have caused the rivers to lose their original value and become exposed to various pollution, resulting decrease in citizens' quality of life. This study aims to estimate citizens' Willingness To Pay (WTP) for water quality improvement in Suyeong River in Busan. To estimate the non-market value of the Suyeong River, the WTP of Busan citizens for water quality improvement was estimated, applying Contingent Valuation Method (CVM). The WTP for improving the water quality from Grade 4(polluted water) to Grade 2(game fish like bass can live in it) was estimated using the water quality ladder concept of the US Environmental Protection Agency, assuming annual donations for five years. For the CVM, the logistic distribution and Spike Model were adopted. As a result, citizens residing in the surrounding area of Suyeong River expressed a higher WTP. Considering more than half of the Busan citizens are aware of the "conservation of nature and ecosystems" as a major function of the Suyeong River, this higher WTP could serve as a basis for improving the value of urban rivers.

• Communications for Statistical Applications and Methods
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• v.3 no.1
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• pp.121-130
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• 1996

본 논문에서는 사회적 통념상 또는 개인적으로 매우 민감한 사안에 대한 조사시 무응답이나 거짓응답으로 인한 비표본오차를 줄여서 추정의 신뢰성을 높일 수 있도록 고안된 확률화응답기법을 이용하여 이지모집단내의 민감집단의 비율을 추정할 때 신분보호 정도가 같게 되는 조건하에서 추정의 효율을 높일 수 있는 의사 2단계 확률화응답기법을 제안하고 여러 형태의 확률화응답기법들과의 효율성 비교를 통하여 제안된 기법이 효율적일 수 있는 조건을 찾아보았다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9A
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• pp.678-683
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• 2003

The pseudo-noise (PN) code acquisition based on the sequential estimation (SE) proposed by Ward performs well only at relatively high chip signal-to-noise ratios (SNRs). In this paper, a seed accumulating sequential estimation (SASE) method and a PN code acquisition system based on it are proposed, which perform well at low chip SNR (of practical interest) also. Then, the mean acquisition time performance of the proposed system is investigated. Numerical results show that the system based on the SASE performs dramatically better than that based on the SE at low chip SNR, and the improvement becomes larger as the period of PN code increases.

• Environmental and Resource Economics Review
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• v.14 no.2
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• pp.447-474
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• 2005

Respondents, in the willingness to pay (WTP) survey, may have preference intensity about their stated WTP values. This study elicited a post-decisional intensity measure for each observed WTP answer for gathering information on the degree of preference intensity. In order to deal with the WTP data with preference intensity, this paper considers using the Type 3 Tobit model. This is usually estimated by the parametric two-stage estimation method assuming homoskedastic and bivariate normal error structure. However, if the assumptions are not satisfied, the estimates are inconsistent. The author has tested the hypotheses of homoskedasticity and normality, and could not accept them at the 1% level. The assumptions required to estimate the parametric Type 3 model are, therefore, too strong to be satisfied. As an alternative the parametric model, this study applies a semiparametric Type 3 Tobit model. The results show that the semiparametric model significantly outperforms the parametric model, and that more importantly, the mean WTP from the parametric model is significantly different from that from the semiparametric model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.947-949
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• 2006

In the microcell or picocell-based system the frequent movements of mobiles bring about excessive traffics into the networks. In this paper we study multi-criteria decision making which can increase estimation accuracy by considering other multiple decision parameters than the received signal strength.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.126-126
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• 2017

수도권 광역상수도는 관로 매설 이후 30년 이상 경과하여 수도관로 사고 발생빈도가 증가하고 있다. 이에 노후관로를 갱생하여 사고예방과 용수공급 안정성 강화를 도모할 필요가 있으며, 이러한 사업의 수행 여부에 대한 판단을 위해서는 사업 시행으로 발생하는 경제적 편익에 대한 정량적 정보가 필요하다. 노후관로 갱생사업의 경제적 편익은 크게 관로사고 피해저감 편익과 복구비용 절감편익으로 구분되는데 후자는 공학적 접근을 통해 비교적 쉽게 평가할 수 있는 반면에, 전자는 평가가 어렵다. 이에 본 논문에서는 조건부 가치측정법이라는 경제학적 기법을 적용하여 관로사고 피해저감 편익을 추정하고자 한다. 수도권 광역상수도 갱생사업의 수혜지역 주민 600 가구를 무작위로 추출하여 수도권 광역상수도 갱생사업이 시행되지 않을 경우 관로사고가 발생할 수 있음을 설명한 후, 관로사고를 막기 위한 지불의사액을 조사하였다. 분석결과 관로사고 피해 회피를 위한 가구평균 지불의사액은 톤당 약 41.7원이었다. 이 정보는 노후관로 갱생사업에 대한 의사 결정시 활용할 수 있다.

• Journal of Korea Port Economic Association
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• v.39 no.1
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• pp.35-46
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• 2023

This study was conducted to evaluating the willingness to pay for marine leisure ships through a contingent valuation method that can estimate the value of non-market economy. The questionnaire adopted a double-bound dichotomous choice Model and the variables for evaluating the amount of willingness to pay consisted of demographic variables and respondent behavior variables, and related information verified through previous studies. As a result of collecting and analyzing a total of 309 questionnaires, the amount of willingness to pay for marine leisure ships was estimated to be 25,510 won. In addition, significant variables affecting the amount of willingness to pay were the experience of visiting the island, satisfaction with the introduction of new maritime transportation, and intention to revisit the island. Through this study, it can be used as a basis for evaluating the economic value of new maritime transportation by estimating the willingness to pay for marine leisure ships using the contingent valuation method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.334-337
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• 2004

차세대 생산 시스템(Next Generation Manufacturing System： NGMS)의 핵심 개념은 분산 생산 시스템과 다품종 소량의 유연 생산 시스템의 지원이다. 이러한 시스템의 구성을 위하여 실시간 데이터에 기반한 예측 모델이 필수적인데, 이러한 예측 기능을 통하여 생산공정의 관리와 운영, 특히 전체 공정관리를 효율적으로 수행할 수 있다. 한편, 공정으로부터 전송된 데이터는 특정한 형태의 지식으로 표현된다. 이러한 지식들은 시스템에 대한 다양한 정보를 가지고 있으므로 정보를 이용하여 시스템 상태를 빠르고 쉽게 진단할 수 있다. 공정 진단은 현재 공정 상태에서 생산되는 제품의 품질을 추정할 수 있는 정보로 활용된다. 본 논문에서는 이러한 개념이 바탕이 되어 공정관리 시스템을 설계하였다. 제안된 시스템의 적용 대상은 반도체 제조 공정의 단위 공정인 에칭 공정이다. 에칭 공정은 공정 중에 연속적인 검사가 수행되지 않고 최종 제품에 대한 검사가 수행되므로 불량 원인을 찾는 것이 쉽지 않다. 따라서 본 논문에서는 공정관리를 위한 의사지원시스템을 통해 공정의 연속적인 간접진단을 수행하고자 하였다. 본 연구에서 사용된 의사지원시스템은 각 공정에서 얻어지는 데이터와 경험적 지식을 토대로 공정시스템의 해석과 진단이 가능한 시스템이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.209-210
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• 2022

For the growth of the marine leisure industry, it is necessary to estimate economic value to review appropriate profitability in advance for the opening of new routes for marine leisure ships. This study aims to analyze the willingness to pay for new marine leisure ships for users of Gyeonggi sea and estimate the economic value. To this end, the amount of willingness to pay was estimated using the conditional value measurement method, and significant factors affecting the payment of usage fees were analyzed. As a result of the study, the average willingness to pay was estimated at KRW 25,510, and it was found that the factors such as "island visit experience" and "satisfaction with means of transportation" had a significant effect on the willingness to pay.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.337-366
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• 2004

Contingent Valuation Method (CVM), as non-market valuation approach, has been criticized on that respondents may not realistically reflect their budget constraints in answering willingness to pay (WTP) for hypothetical CV questions. This paper empirically estimates the income calibration factor associated with CV responses through combining travel cost method and contingent valuation method in a utility-theoretic framework. The joint model of recreation demand function and contingent WTP function was applied to an important case study on the Man Kyoung River system, whose water quality is at issue because of the Sae Alan Kum reclamation project. Relevant economic variables such as price, income and water quality had significant influence as anticipated by the economic theory. Equally important, the income calibration factor was not significantly different from one, suggesting that the systematic discrepancies of CV responses relative to the actual behavior was not detected at least in terms of budget exaggeration. Overall, this study supports the notion that carefully designed CVM studies can provide informative data on individuals' willingness to pay for environmental quality changes.