• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.7-14
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• 2005

Traffic congestion causes enormous social costs as well as loss of travel time and waste of energy. Though the Seoul metropolitan government implemented various forms of transportation policies such as urban road pricing and public transportation reform, traffic volume which across the Seoul metropolitan borders have greatly increased because of housing land development in suburban area. The purpose of this study is to estimate individual's willingness-to-pay(WTP) for extensive implementation of congestion pricing through policy-mix with bus rapid transit(BRT) system. So the field survey interviews carried out. The empirical analysis was done with priority given to the following two topics; derivation of individual WTP and prior evaluation of policy effect from the equity aspect. To estimate individual WTP, we adopted contingent valuation method (CVM). The former is to estimate individual WTP for respondent's maintaining his/her transit pattern when he/she is faced with congestion pricing by using compensating variation(CV) concept. And, the latter aims at evaluating policy effect from the equity aspect by calculating the Proportion of WTP to average income using WTP in income bracket for policy scenarios.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.820-831
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• 2015

In a deregulated electricity market, congestion of the transmission lines is a major problem the independent system operator (ISO) would face. Rescheduling of generators is one of the most practiced techniques to alleviate the congestion. However, not all generators in the system operate deterministically and independently, especially wind power generators (WTGs). Therefore, a novel optimal rescheduling model for congestion management that accounts for the uncertain and correlated power sources and loads is proposed. A probabilistic power flow (PPF) model based on 2m+1 point estimate method (PEM) is used to simulate the performance of uncertain and correlated input random variables. In addition, the impact of direct electricity purchase contracts on the congestion management has also been studied. This paper uses artificial bee colony (ABC) algorithm to solve the complex optimization problem. The proposed algorithm is tested on modified IEEE 30-bus system and IEEE 57-bus system to demonstrate the impacts of the uncertainties and correlations of the input random variables and the direct electricity purchase contracts on the congestion management. Both pool and nodal pricing model are also discussed.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.428-431
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• 2002

본 논문에서는 경쟁적 전력시장에서 송전제약에 관한 비용을 적절히 할당하는 방법을 제시하고자 한다. 혼잡비용을 할당하는 방법으로는 모든 사용자들에게 똑같이 배분하는 방법과 혼잡의 원인을 제공한 사용자에게 정도에 따라 가중하여 혼잡비용을 할당하는 nodal pricing과 zonal pricing이 있다. 계산의 신속성과 복잡성으로 인해서 zonal pricing이 유용한 방법으로 사용되고 있다. 기존의 분할 기술은 계통운영자가 설정한 한계범위의 모선들을 zone으로 형성하는 통계적인 방법을 사용했다. 이 방법은 운영자의 임의성이 반영되는 모호한 알고리즘이라는 단점을 가지고 있다. 그래서 본 논문에서는 한계비용민감도를 이용한 계통분할 방법을 제안하였다.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.590-592
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• 2003

The presence of congestion in transmission system can reduce the market size and split bulk system into smaller system. Consequently, this creates the problem concerining Local Market Power and can be main reason for the inclose of practical market price. In this paper, a range of indices have been derived to quantify the degree of local market power through statistical analysis in the uniform pricing market. Application of the indices has been illustrated using the electricity market in Korea. The indices proposed in this paper seem to be effectively applied in electricity market under uniform pricing scheme.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.139-148
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• 2006

In order to incorporate substitution effects between different transport modes in optimal road Pricing, relating economic theories and models have been reviewed. It includes unconstrained optimization problem of maximizing separable and non-separable social net benefit functions of different substitutable urban transport modes. In doing that, the problem and limitations such as path-independent conditions with the asymmetric Jacobian of the objective function have been reviewed. Consequently, a plausible way of deriving optimal road price under interdependent market conditions has been suggested so that the idea can help identifying desirable and acceptable urban transport policy alternatives in a more comprehensive way.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.97-104
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• 2015

PURPOSES : Expressways experience chronic and recurring congestion, especially during weekends and holidays, because of the increased demands for leisure-related travel. The alternatives to solve chronic and recurring congestion may be three-fold: (1) physical expansion of expressway capacities, (2) road pricing, and (3) temporal and spatial distribution of traffic demands. Among these, the third alternative may be the most cost-effective method for the Korea Expressway Corporation (KEC) that can be achieved by using the existing ITS infrastructure. METHODS : KEC initiated a pilot study in which the traffic on congested expressways was managed by providing traffic condition information (i.e., travel times) of neighboring national highways for taking detours via variable message signs (VMS). This study aimed to estimate the detour rate, and the two pilot studies on Seohaean and Yeongdong expressways yielded many benefits. RESULTS : It was revealed that the total length of congestion segments decreased by 7.8 km, and the average travel speed increased by 5.3 km/h. CONCLUSIONS : Based on these findings, it was concluded that the propagation of detour information via VMSs during congestion hours can help reduce congestion on expressways and increase the benefits of the entire network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.268-276
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• 2007

Transmission congestion is one of the key factors to local market power in competitive electricity markets. Financial transmission rights provide the financial protection to their holders by paying back the congestion rent. A variety researches have shown that the existing trading mechanisms on transmission right can exacerbate market power. This paper proposes an alternative methodology in mitigating the local market power using the Contingent Transmission Rights on the locational marginal pricing scheme. The proposed methodology was demonstrated with the Optimal Power Flow.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.8
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• pp.379-384
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• 2002

In the competitive electricity market, various pricing methods are developed and practiced in many countries. Among these pricing methods, marginal loss factor(MLF) can be applied to reflect the marginal cost of network losses. For the calculation of MLF, power flow method has been used to calculate system loss deviation. However, this power flow method shows some shortcomings such as necessity of regional reference node, and absence of an ability to consider network constraints like line congestion, voltage limit, and generation output limit. The former defect might affects adversely to the equity of market participants and the latter might generate an inappropriate price signals to customers and generators. To overcome these defects, the utilization of optimal power flow(OPF) is suggested to get the system loss deviation in this paper. 30-bus system is used for the case study to compare the MLF results by the power flow and the OPF method for 24-hour dispatching and pricing, Generator payment and customer charge are compared with these two methods also. The results show that MLF by OPF reflects the power system condition more faithfully than that of by the conventional power flow method

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.2
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• pp.9-17
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• 2006

Over the last couple of years, established Cumulus Pricing Scheme(CPS) has become an important research issue for efficiently charging differentiated internet services. This paper proposes the adjusted CPS technique that expressed information of over or under-use of resources in bandwidth. And, 1 propose CPS with respect to the six main pricing and charging conditions. Also, accumulation technique may indicate an information between specified charging and eventually requires to adapt the initial contract. So called red and green Cumulus Points(CP) are used to judge the behavior of customer. At this point, the actual resource consumption is described by function v(t) at time t.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.159-169
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• 2008

The aim of this paper is to research the changes of social welfare by internalizing external cost, especially the maintenance cost. Main target of this paper is the Cheonan$\sim$Nonsan Line, where private capital highway, national highway and local road are competing against each other. Considering the realistic difficulties in applying the First Best pricing, this paper applied the Second Best pricing, applying the maintenance cost, in lieu of the already mentioned. The demand functions of the toll roads were built through regression analysis. By reflecting the maintenance cost to the toll fee, It was able to confirm the variation of social welfare deriving from the traffic assign change but also the aspects of toll revenue at the same time. Result of applying the Second Best pricing shows merely a small change in social welfare. However, in the aspect of finance, it is analyzed that there will be about 13 billion won worth of financial effectiveness which will contribute to the reduction of the national financial support.