• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.219-231
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• 2003

This paper aims to study the problem of combined harvesting of a system involving one predator and two prey species fishery in which the predator feeds more intensively on the more abundant species. Mathematical formulation of the optimal harvest policy is given and its solution is derived in the equiblibrium case by using Pontryagin's Maximum principle. Dynamic optimization of the harvest policy is also discussed by taking E(t), the combined harvest effort, as a dynamic variable. Biological and bioeconomic interpretations of the results associated with the optimal equilibirum solution are explained. The significance of the constraints required for the existence of an optimal singular control are also given.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.105-107
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• 2002

This paper provides calculation and decomposition of Bus Incremental Cost on Power System Operation. In this method we show deriving Shadow Price from state variables in Optimal condition. And the decomposition can give a detailed description of each Bus Incremental Cost. The proposed method is applied to IEEE-30 and results shows the effectiveness of the method.

• Environmental and Resource Economics Review
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• v.4 no.1
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• pp.91-102
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• 1994

우리나라에서 다른 광물자원보다 매장량이 비교적 풍부하고 에너지원으로서 총에너지소비량에서 중요한 몫을 차지해 온 석탄의 희소성을 측정하기 위하여 시장가격을 사용할 경우 그 결과는 실질고갈상태를 왜곡시킬 수 있다. 왜냐하면 정부가 석탄가격을 관리하며 생산원가보다 낮은 부분에 대해서는 보조금이나 장려금을 지급해 왔기 때문이다. 그러므로 본 연구는 쌍대성이론(duality theory)을 토대로 한 할버슨-스미스(Halvorsen-Smith, 1984) 모형을 이용하여 매장되어 있는 광물자원의 암묵가격(shadow price)을 실증적으로 추정함으로써 우리나라 석탄자원의 희소성을 측정하였다. 최종생산물의 가격으로 측정된 희소성지표에 의하면 우리나라의 석탄자원은 매우 완만하게 고갈되어 가고 있는 반면에 광석의 암묵가격으로 본 회소성지표에 의하면 그보다 더 빠른 속도로 고갈되어 가고 있음을 알 수 있었다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.9
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• pp.528-534
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• 2003

In this paper we propose the new method for calculating the Bus Incremental Cost using bus voltage magnitude and angle. And perform the decomposition of Bus Incremental Cost on power system operation. In this method, we calculate the Shadow Price that is derived from using power flow calculation results. The proposed Method is applied to IEEE-30 and the result shows the effectiveness of the method.

• Environmental and Resource Economics Review
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• v.6 no.1
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• pp.45-57
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• 1996

공기업(公企業)이 정부의 수익성사업이나 국가기간사업을 독점적으로 수행함에 있어 야기되는 X-비효율성 및 기술혁신의 결여, 사기업(私企業)의 경우와 달리 이윤극대화라는 단일 목적만을 추구할 수 없는 공기업(公企業)의 경영여건, 노사분규로 인한 요소사용비율의 변화, 그리고 각종 정부규제등 여러 제약된 여건하에서 생산요소의 비효율적 배분으로 인하여 생산비용의 최소화가 이루어지고 있다고는 볼 수 없다. 본 연구에서는 공기업(公企業)을 대상으로 실증적으로 시장가격의 함수인 암묵가격(暗默價格)(shadow price)을 설명변수로 사용하는 일반비용함수(一般費用函數)(generalized cost function)를 추정한 후, 효율성검정을 실시하여 생산비용의 최소화여부를 알아본다. 한국 전기업의 '88년 '93년의 2년간 10개 시 도별 자료를 사용하여 효율성검정을 실시한 결과, 생산비용의 최소화는 이루어지고 있지 않음을 알 수 있었다. 생산의 비효율성으로 인하여 비용은 평균 27.4% 증가되었으며 자본과 노동은 각각 적정수준보다 평균 10.6%, 2.1% 만큼 적게 사용된 반면, 연료는 255% 만큼 필요 이상으로 사용되었다.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.115-138
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• 2009

The purpose of this paper is to clarify the main components of economic growth and the effects of environmental factorson productivity by comparing traditional productivity growth and environmentally-adjusted productivity growth in 28 Chinese regions based on growth accounting analysis. To do this, we measured the shadow prices of SOx for the 28 Chinese regions. This study found that the annualized growth rate of output in the 28 Chinese regions was almost 10.07% for 1999-2005, though the growth rate was higher in the eastern region than in the middle and western regions. The average traditional productivity was 3.58%, again with the eastern region showing the highest level. The average environmentally-adjusted productivity of the three regions was about 3.56%, which is similar to the level of traditional productivity. This implies that activities regarding pollution reductions in the 28 Chinese regions have not been practiced, even though environmental regulations have been strengthened. Therefore, the regional and central governments should strengthen environmental regulations and strictly enforce them.

• Journal of Korea Port Economic Association
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• v.22 no.4
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• pp.59-79
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• 2006

In this paper, we analyse the comparative competitiveness of the 10 major logistic hub cities in China. First, using the input distance function, we calculated the technical efficiencies and the opportunity costs of the transport infra structure investments. Then, based on not only these supply side factors but also demand side, the overall comparative competitiveness by cities are analyzed. Our main findings are as follows: early developed, larger cities such as Shanghai, Guangzhou, Shenzhen are technically efficient but their opportunity costs of the additional transport investments are higher than the other cities. We also found that overall competitiveness of these larger and leading logistic hub cities are dominant over the small and newly developed logistic cities.

• Environmental and Resource Economics Review
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• v.28 no.1
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• pp.61-93
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• 2019

This study is to apply Hedonic Price Method in analyzing residents' preferences for three types of urban green space (UGS, rivers, urban parks, and forests) near the apartment complexes in Seoul. Based on hedonic price function estimation results, residents in Seoul preferred for the urban amenity that was provided by the view and accessibility (in terms of both within 10 minutes and distance) of rivers and urban parks near the apartment complexes, but not forests. The annual benefits calculated using the shadow prices are about 550~600 thousand won for the urban park views and about 800 thousand won for the accessibility, which is 2-3 times higher than river views and accessibility. On the other hand, forest views and accessibility did not have significant effects on apartment prices, except the view of Bukhan mountain for the residents of Gangbuk area. Based on the empirical results, Seoul residents' preferences for urban parks would have important implications for the urban park sunset program that will be initiated from July 2020.

• Environmental and Resource Economics Review
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• v.22 no.3
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• pp.459-479
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• 2013

To assess the feasibility of 'low carbon, sustainable growth' policy pursued of the Chinese government, this paper first measures technical efficiency, $CO_2$ shadow prices, and indirect Morishima elasticity of substitution between capital and energy for 24 of manufacturing sectors in Beijing and Chongqing, in which China launched pilot carbon emissions trading scheme, by estimating the input distance function. Based on these results, then the potential for $CO_2$ reduction, cost savings from emissions trading, and the effectiveness of capital investment in reducing $CO_2$ are compared across industries and provinces. In 2010, manufacturing industries in Beijing and Chongqing could potentially reduce the largest $CO_2$ emissions, amounting 5.2 and 17 million tons, respectively, by achieving 100% technical efficiency. While, on average, Chongqing has a comparative advantage in the cost savings from carbon trading over Beijing, Beijing is more likely to reduce $CO_2$ by expanding capital investment.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.272-275
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• 2009

Carbon finance is the investment in Greenhouse Gas (GHG) emission reduction projects in developing countries and countries with economies in transition within the framework of the Kyoto Protocol's Clean Development Mechanism (CDM) or Joint Implementation (JI) and with creation of financial instruments, i.e., carbon credits, which are tradable in carbon market. The additional revenue generated from carbon credits will increase the bankability of projects by reducing the risks of commercial lending or grant finance. Meantime, it has also demonstrated numerous opportunities for collaborating across sectors, and has served as a catalyst in bringing climate issues to bear in projects relating to rural electrification, renewable energy, energy efficiency, urban infrastructure, waste management, pollution abatement, forestry, and water resource management. Establishing additionality is essential for successful CDM project development. One of the key steps is the investment analysis. As guided by UNFCCC, financial indicators such as IRR, NPV, DSCR etc are most commonly used in both Option II & Option III. However, economic indicator such as Economic Internal Rate of Return(EIRR) are often overlooked in Option III even it might be more suitable for the project. This could be due to the difficulties in economic analysis. Although Asian Development Bank(ADB) has given guidelines in evaluating EIRR, there are still large amount of works have to be carried out in estimating the economic, financial, social and environmental benefits in the host country. This paper will present a case study of a CDM development of a 18 MW hydro power plant with carbon finance option in central Vietnam. The estimation of respective factors in EIRR, such as Willingness to Pay(WTP), shadow price etc, will be addressed with the adjustment to Vietnam local provincial factors. The significance of carbon finance to Vietnam renewable energy development will also be addressed.