• 대한산업공학회지
• /
• 제13권2호
• /
• pp.65-77
• /
• 1987

Congestion occurs whenever users interfere with each other, while competing for scarce resources. In a congested market, such as a telecommunication service market, users of telecommunication services incur costs in using the service in addition to the price. The user's own time costs involved in learning to use the service, waiting for the service, and making use of the service are typically greater than the price of telecommunication services. A market equilibrium analysis is performed in which a method for user demand aggregation is developed. The effects of price changes on user demands and market demands for congested services are examined. It is found that total market demands may increase as the price for less-congested services increase under certain demand conditions. This suggests that a nonuniform pricing scheme for a congested service may improve the utilization of the congested system. The sign of price cross-elasticity for congested services is show to vary with demand conditions. A possible complementary property of congested services is found and the implication of such a property is discussed. It is argued that such a complementary property may lead to a cross subsidy in a market with congestion. Finally, comparisons between uniform pricing and nonuniform pricing policies are made. A specific numerical example is given to show that a nonuniform pricing policy may be Pareto superior to a uniform pricing policy.

• Journal of Communications and Networks
• /
• 제16권6호
• /
• pp.627-638
• /
• 2014

In this paper, we study the joint price and power allocation in spectrum sharing macro-femtocell networks. The proposed game theoretic framework is based on bi-level Stackelberg game where macro base station (MBS) works as a leader and underlaid femto base stations (FBSs) work as followers. MBS has fixed data rate and imposes interference price on FBSs for maintaining its data rate and earns revenue while FBSs jointly adjust their power for maximizing their data rates and utility functions. Since the interference from FBSs to macro user equipment is kept under a given threshold and FBSs compete against each other for power allocation, there is a need to determine a power allocation strategy which converges to Stackelberg equilibrium. We consider two cases for MBS power allocation, i.e., fixed and dynamic power. MBS can adjust its power in case of dynamic power allocation according to its minimum data rate requirement and number of FBSs willing to share the spectrum. For both cases we consider uniform and non-uniform pricing where MBS charges same price to all FBSs for uniform pricing and different price to each FBS for non-uniform pricing according to its induced interference. We obtain unique closed form solution for each case if the co-interference at FBSs is assumed fixed. And an iterative algorithm which converges rapidly is also proposed to take into account the effect of co-tier interference on interference price and power allocation strategy. The results are explained with numerical simulation examples which validate the effectiveness of our proposed solutions.

• 대한수학회보
• /
• 제48권2호
• /
• pp.413-426
• /
• 2011

Two types of new methods with variable time steps are proposed in order to valuate binary options efficiently. Type I changes adaptively the size of the time step at each time based on the magnitude of the local error, while Type II combines two uniform meshes. The new methods are hybrid finite difference methods, namely starting the computation with a fully implicit finite difference method for a few time steps for accuracy then performing a ${\theta}$-method during the rest of computation for efficiency. Numerical experiments for standard European vanilla, binary and American options show that both Type I and II variable time step methods are much more efficient than the fully implicit method or hybrid methods with uniform time steps.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권1호
• /
• pp.43-50
• /
• 2005

The presence of transmission congestion may reduce the market size and split the bulk power system into smaller systems. Consequently, this can be a key factor to the increase in market price. This paper analyzes the effect of exercising local market power on the market price, and derives a range of indices which quantify the degree and incentive of local market power through statistical analysis in an electricity market with uniform pricing scheme. The applicability and effectiveness of the derived indices on competitive electricity markets are demonstrated on the Korea electricity market.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제17권4호
• /
• pp.295-306
• /
• 2013

In this paper, we consider the adaptive multigrid method for solving the Black-Scholes equation to improve the efficiency of the option pricing. Adaptive meshing is generally regarded as an indispensable tool because of reduction of the computational costs. The Black-Scholes equation is discretized using a Crank-Nicolson scheme on block-structured adaptively refined rectangular meshes. And the resulting discrete equations are solved by a fast solver such as a multigrid method. Numerical simulations are performed to confirm the efficiency of the adaptive multigrid technique. In particular, through the comparison of computational results on adaptively refined mesh and uniform mesh, we show that adaptively refined mesh solver is superior to a standard method.

• 대한교통학회지
• /
• 제32권6호
• /
• pp.675-685
• /
• 2014

본 연구는 고속도로의 혼잡 완화를 위해 차선통행료 방식에 근거한 고속도로 구간별 차등요금 부과전략을 개발하는데 그 목적이 있다. 이를 위해 상위단계의 교통혼잡 최소화를 위한 각 구간의 주행요금을 산정하는 문제와 하위단계의 가변수요 통행배정문제로 구성된 바이레벨 형태의 모형을 제시하였다. 상위단계 문제의 최적 해를 찾기 위해 민감도 분석 기반의 알고리즘을 이용하였으며, 제안된 모형의 검증을 위해 수정된 Sioux-Falls 네트워크에 적용하였다. 적용 결과 차등요금 부과전략 적용 시 균일한 요금을 징수한 경우보다 교통혼잡이 개선된 것으로 나타났으며 이는 고속도로 구간의 혼잡 완화로 인한 것임을 확인할 수 있었다. 본 연구는 고속도로 특정 구간의 과도한 혼잡으로 인해 발생하는 비효용을 절감하기 위한 수요관리 방안으로 적용될 수 있다.

• 정보과학회 논문지
• /
• 제44권8호
• /
• pp.854-859
• /
• 2017

기지국(Base Station)에서 인기있는 콘텐츠(비디오)를 캐싱하는 것은 전송 대기 시간을 줄일 수 있는 효율적인 방법이다. 본 논문에서는 콘텐츠 제공자(CP)가 캐싱 절차에 참여하도록 동기를 부여하기 위해 무선 네트워크에서의 사전 인센티브 캐시 메커니즘을 제안한다. 하나 이상의 Infrastructure Provider(InP)와 많은 CP로 구성되어 있는 시스템에서, InP는 InP의 기지국에서 캐시하는 파일 수를 결정하기 위해 CP가 경쟁하는 동안 수익을 극대화할 수 있도록 CP에 청구되는 가격을 정의하는 것을 목표로 한다. 또한 InP와 CP는 Stackelberg 게임이론 내에서 각각 선도자와 추종자로 정의된다. Backward Induction을 기반으로, 각 CP가 각 기지국에서 임대한 캐시 공간의 양을 정확하게 측정한 후, 최적화 문제를 해결함으로써 InP가 각 CP를 임대하는 가격을 계산한다. 이것은 비 균일 가격 체계를 고려한 점에서 기존 연구와 차이가 있다. 수치 결과는 제안 된 방법을 통해 InP의 이익이 균일 가격 책정보다 높다는 것을 보여준다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.737-739
• /
• 2004

The domestic power system established with Cost-Based-Pricing(CBP) from April 2001. The system is a uniform pricing system. System Operator(50) establishes a Price Setting Schedule by the prediction of consumption and the presented bid price(generation cost) of the generation utility. But the Price Setting Schedule doesn't take account of the constraint of the system. This cause a transmission congestion, constrained-on generation and constrained-off generation. This Paper search the way of the increasing efficiency of domestic power system through the redemption of congestion charge.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제28권4호
• /
• pp.329-341
• /
• 2021

In this study, we consider an efficient and accurate finite difference method for the four underlying asset equity-linked securities (ELS). The numerical method is based on the operator splitting method with non-uniform grids for the underlying assets. Even though the numerical scheme is implicit, we solve the system of discrete equations in explicit manner using the Thomas algorithm for the tri-diagonal matrix resulting from the system of discrete equations. Therefore, we can use a relatively large time step and the computation of the ELS option pricing is fast. We perform characteristic computational test. The numerical test confirm the usefulness of the proposed method for pricing the four underlying asset equity-linked securities.

• 대한가정학회지
• /
• 제47권6호
• /
• pp.39-49
• /
• 2009

The purpose of this study were to compare school uniforms made in major and minor companies. Especially, purchasing motives, fitting satisfaction, and mending behaviors of school uniform were compared by middle and high school students. The most evident difference was exhibited in purchasing motive. Brand preference was the most important criterion in purchasing motive from a major company, while good pricing was the most important criterion in purchasing motive from a minor company. Apart from purchasing motive, purchasing behaviors such as fitting satisfaction, mending and mended part of school uniforms were not significantly different in relation to sex, grade, and type of company. These results indicate that major companies should consider lowering their prices and also adopt a high quality strategy for school uniform production. Minor companies need to identify areas of differentiation between themselves and larger companies, and produce niche market products that are for appealing to teenagers with a tendency to orient towards brands instead of quality. Furthermore, mature teenagers as consumers of school uniforms are receptive towards competition for reasonable price.