• Title/Summary/Keyword: 스파이크 모형

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Numerical Simulation and Experiment on Supersonic Air-Breathing Laser-Spike Propulsion Vehicle (초음속 공기 흡입식 레이저 스파이크 추진 비행체에 관한 수치 해석 및 실험적 연구)

  • Kim Sukyum;Kim Young-Taek;Jeong In-Seock
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.57-61
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    • 2004
  • As a kind of application of laser propulsion, air-breathing laser-spike engine can be designed for aircraft in atmospheric flight. Laser-spike engine generates thrust using the blast wave induced by laser energy instead of combustion process. And this engine use air as propellant, therefore, it need no on board propellant. For experimental study, supersonic wind tunnel and spark generator were used. Flow visualization was performed using 2-dimensional laser-spike engine model And numerical simulation of the corresponding case for the experiment was done and compared with experimental case. Detailed results will be discussed at the presentation.

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Estimating Spot Prices of Restructured Electricity Markets in the United States (미국 전기도매시장의 전기가격 추정)

  • Yoo, Shiyong
    • Environmental and Resource Economics Review
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    • v.13 no.3
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    • pp.417-440
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    • 2004
  • For the behavior of the wholesale spot price, a regime switching model with time-varying transition probabilities was estimated using the data from the PJM (Pennsylvania-New Jersey-Maryland) market. By including the temperature as an explanatory variable in the transition probability equations, the threshold effect of changing regime is clearly enhanced. And hence the predictability of the price spikes was improved. This means that the model showed a very clear threshold effect, with a low probability of switching for low loads and low temperatures and a high probability for high loads and high temperatures. And temperature showed a clearer threshold effect than load does. This implies that weather-related contracts may help to hedge against the risk in the cost of buying electricity during a summer.

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A Comparison of Parametric and Non-parametric Approaches Dealing with Zero Responses in CVM Research (조건부 가치측정법에서 영(0)의 응답처리를 위한 모수적 추정법과 비모수적 추정법의 비교연구)

  • Lee, Joosuk;Choi, Eun-Chul
    • Environmental and Resource Economics Review
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    • v.22 no.2
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    • pp.281-307
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    • 2013
  • There has been some debates about zero willingness to pay in contingent valuation method research. Therefore, this paper tries to estimate and compare the results of various models to handle zero willingness to pay responses. For this purpose, we have employed parametric estimation such as the mixed model and the spike model, as well as non-parametric estimations. As a result, these models derived WTP estimate different from conventional model, but they also show some weakness. Therefore, in future research, more conservative estimate of the model should be to use rather than specific model.

The Estimation of Users' Benefit in Next Generation Urban and Rural Smart Weather Service Technique Research and Development Project (차세대 도시.농림 융합 스마트 기상서비스기술 개발 사업의 이용자 측면 편익 추정)

  • Lee, Joo Suk;Yoo, Seung Hoon
    • Journal of Korea Technology Innovation Society
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    • v.16 no.3
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    • pp.630-649
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    • 2013
  • Korea Meteorological Administration has promoted the next generation urban and rural smart weather service project. The purpose of this project is to provide the necessary information to urban and rural districts by using the subdivided meteorological information. This study attempts to assess the value of the next generation urban and rural smart weather service project by using contingent valuation method. According to estimating result, annual mean willingness to pay per household for the next generation urban and rural smart weather service project is 2,947 won.

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An Economic Value for Construction of Ecological Stream in Hong Cheon Area, Korea (홍천강 생태하천 복원사업의 경제적 가치)

  • Koo, Yoonmo;Kang, Hyeongsik;Lee, Misuk
    • Korean Journal of Environment and Ecology
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    • v.28 no.1
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    • pp.71-79
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    • 2014
  • The goal of this study is to estimate economic benefit of restoring ecological stream of Hong Cheon river. The benefit is determined by estimating willingness-to-pay for the value of Hong Cheon river because it is a non-market good which is difficult to be measured in terms of monetary value. Specifically, the spike model, one of the contingent valuation methods, is used to distinguish respondents having zero willingness-to-pay for Hong Cheon river. The results show that a household located near the Hong Cheon river is willing to pay 3,300~4,628 Korean Won per year, while a household not located near the Hong Cheon river is willing to pay 1,308~2,929 Korean Won per year. Thus, total benefit of restoring ecological stream of Hong Cheon river is estimated as 97.6~216.3 billion Korean Won.

Estimation of citizens' Willing To Pay for water quality improvement on urban rivers (도시하천 수질 개선을 위한 도시민의 지불의사 추정)

  • Kang, Ji Yoon;Kim, Keewook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.463-463
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    • 2022
  • 도시하천은 급속한 경제성장과 개발 등 여건변화에 따라 크게 변화되어왔다. 이에 하천은 본연의 모습과 가치를 잃고 인공적인 모습으로 변해 하천의 주요 기능인 자정작용, 생태계 건강성 유지 등의 기능을 잃고 도시 활동에 따른 오염물질에 노출되어가고 있는 실정이다. 이로 인한 부정적인 영향으로 도시민의 삶의 질과 만족도 또한 하락되고 있다. 본 연구에서는 부산의 대표하천인 수영강을 대상으로 도시하천 수질 개선을 위한 도시민의 지불의사를 추정하였다. 비시장가치를 추정하기 위해 조건부가치측정법(CVM, Contingent Valuation Method)을 적용하여 수질개선에 따른 지불의사(WTP, Willingness To Pay)를 파악하고 경제적 가치를 추정하였다. 가상시나리오는 EPA, water quality ladder의 개념을 이용하여 현재 수영강 수질이 오염된 물(4등급)이라고 가상시장을 설정하고 낚시가 가능한 수준(2등급)까지 개선을 시키고자 할 때의 지불의사를 물었다. 이때 지불수단은 기부금의 형태로 연 1회 향후 5년간 지불기간을 설정하였다. WTP 모형추정은 KDI에서 제시하고 있는 로지스틱분포 함수와 스파이크 모형을 사용하여 WTP를 추정하였다. 스파이크 모형의 추정결과 평균 지불의사액은 12,255원으로 부산광역시 전체 가구 수인 1,392,291가구(2019년)에 적용할 경우 향후 5년간 연 170억 원의 재원을 확보할 수 있는 것으로 나타났다. 지불의사 추정결과 수영강 인접 지역주민의 지불의사가 높게 추정되었고, 부산시민이 수영강을 자연과 생태보전 기능하천으로 인지하고 있음(56.5%)을 고려 할 때, 하천환경개선을 통한 지불의사의 상승은 도시하천 가치 향상이 될 수 있을 것으로 판단된다. 또한 도시민의 기대수준 충족과 더불어 도시하천 가치상승을 위한 부족한 재원까지도 조달 할 수 있는 방안의 기초를 마련 할 수 있을 것이라 판단된다.

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The Recreational Benefits of the Jangheung Multi-purpose Dam (장흥댐의 레크리에이션 편익 추정)

  • Park, So-Yeon;Lim, Seul-Ye;Ryu, Moon-Hyun;Yoo, Seung-Hoon
    • Journal of the Korean Regional Science Association
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    • v.31 no.3
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    • pp.79-97
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    • 2015
  • This paper attempts to quantify the economic value of the recreational benefits from the Jangheung dam. To this end, the contingent valuation (CV) survey was administrated to a sample of randomly selected 1,000 households from the national population. We used single-bounded model as a method of eliciting the willingness to pay (WTP) and applied a spike model to deal with zero WTP responses (72.5%) from the CV survey. The respondents were asked to state whether to pay a given amount through additional higher income tax once a year for next ten years. The results show that the annual recreational benefits of the Jangheung dam are estimated to be 1,348 won per household, which is statistically significant at the 1% level. Expanding the value to the national population gives us 24.9 billion won per year.

Assessment of Economic Value of Sangkwan Multi-Purpose Reservoir (I): Benefits of Environmentally-Enhancing Water (상관 다기능 저류지 조성의 경제적 편익 평가(I): 환경개선용수 공급편익을 중심으로)

  • Lee, Joo-Suk;Ryu, Moon-Hyun;Yoo, Seung-Hoon
    • 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.

Measuring the Economic Benefits of the Tap Water Quality Improvement in Ulsan (울산시 수돗물 수질개선의 편익 추정)

  • Kwak, So-Yoon;Yoo, Seung-Hoon
    • 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.

The external benefit of combustible waste-to-energy: A contingent valuation study (가연성 폐기물 에너지화의 외부편익 : 조건부 가치측정법의 적용)

  • Lim, Seul-Ye;Kim, Ho-Young;Yoo, Seung-Hoon
    • Journal of Energy Engineering
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    • v.22 no.3
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    • pp.270-282
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    • 2013
  • Combustible waste into energy policy is an effective method to respond to climate change and depletion of fossil fuels. Combustible waste into energy is the process of generating energy in the form of electricity and/or heat from the combustible waste such as vinyl, paper and plastic. This study tries to estimate the external benefit of enhancing the ratio of combustible waste into energy to primary energy from 1.89% to 5% using contingent valuation(CV) method. To this end, we report the results from a CV survey to elicit the willingness to pay (WTP) for combustible waste into energy. A CV survey of 500 households was conducted in the Seoul by using person-to-person interviews. Thus, the procedures of applying and the findings from the one-and-one-half bounded dichotomous choice spike model used to deal with the zero WTP responses are provided in the paper. The results show that the average WTP is estimated to be 2,724 won per household per month and statistically significant at the 5% level. Expanding the value to the Seoul gives us an aggregate value of 13.7 billion won per year.