• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.6
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• pp.259-264
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• 2006

This paper addresses the collusive bidding that functions as a potential obstacle to a fully competitive wholesale electricity market. Cooperative game is formulated and the equation of its Nash Equilibrium (NE) is derived on the basis of the supply function model. Gencos' willingness to selectively collude is expressed through a bargain theory. A Collusion Incentive Index(CII) for representing the willingness is defined through computing the Gencos' profits at NE. In order to keep the market non-cooperative, the market operator has to know the highest potentially collusive combination among the Gencos. Another index, which will be called the Collusion Monitoring Index(CMI), is suggested to detect the highest potential collusion and it is calculated using the marginal cost functions of the Gencos without any computation of NE. The effectiveness of CMI for detecting the highest potential collusion is verified through application on many test market cases.

• Computational Structural Engineering
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• v.10 no.1
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• pp.159-171
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• 1997

This study investigates the stress distribution in a transversely isotropic medium containing a spheroidal cavity where the medium is under uniaxial tension in z-direction in one case and pure shear in the plane of isotropy in another case. The technical approach used in this study combines exact analytical and numerical methods. The exact analytical method is based upon three potential functions taken in terms of the Legendre associated functions of the first and second kind. The numerical method is based upon the finite difference approach. Numerical results concerning the two loading conditions with five anisotropic materials are presented.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.1-11
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• 2006

This paper aims to develop a GIS(Geographic Information System) application model as a decision-making support system in order to evaluate the potential of forests according to their functions, or to classify forest functions. The forest functions analyzed in this study are as follows: production of timber, stable supply of water resources, forest hazards prevention, recreation in forests, conservation of living conditions and natural environment. Using a model possible to evaluate the potential of each forest function and to assort forest functions by making priority-based decisions according to the functions, as well as allowing for various possible analysis environments, its application has been reviewed. Factors for assessing the forest functions could be built by using the following three categories: four maps-topographical map, vegetation map, forest site map and basic forest land use map-whose quantitative drawings had already been made; other self-established maps, such as one indicating the location of sawmills, location map of expressway interchanges, and spatial data of national population distribution map; and attribute data of population and precipitation. The GIS application developed here contributes to the evaluation of forest functions in all the subject areas by map units and national forest management districts based upon the assessment system.

• Honam Mathematical Journal
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• v.27 no.2
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• pp.195-203
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• 2005

We show that the exact Bergman kernel function associated to a $C^{\infty}$ bounded domain in the plane relates the derivatives of the Ahlfors map in an explicit way. And we find several formulas relating the exact Bergman kernel to classical kernel functions in potential theory.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.157.6-157
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• 2001

We estimated various neuron functions to construct of engineering neurons, which are the combination of sigmoid, linear, sine, quadric, double/single bended, soft max/minimum functions. These combinations are estimated by the property on the potential surface between the learning points, calculation speed, and learning convergence; because the surface depends on the inference ability of a neuron system; and speed and convergence are depend on the efficiency on the points of engineering applications. After the evaluating discussions, we can select more appropriate combination than original sigmoid function´s, which is single bended function and linear one. The combination ...

• Journal of the Chungcheong Mathematical Society
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• v.11 no.1
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• pp.163-172
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• 1998

In this paper, we will study properties of the Green's potential for the Green's function of B which is defined in [8]. In particular, we will investigate boundary behavior of some functions related with Green's function within tangential approach regions that were used in [4].

• Honam Mathematical Journal
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• v.35 no.4
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• pp.667-677
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• 2013

A remarkably large number of integrals involving a product of certain combinations of Bessel functions of several kinds as well as Bessel functions, themselves, have been investigated by many authors. Motivated the works of both Garg and Mittal and Ali, very recently, Choi and Agarwal gave two interesting unified integrals involving the Bessel function of the first kind $J_{\nu}(z)$. In the present sequel to the aforementioned investigations and some of the earlier works listed in the reference, we present two generalized integral formulas involving a product of Bessel functions of the first kind, which are expressed in terms of the generalized Lauricella series due to Srivastava and Daoust. Some interesting special cases and (potential) usefulness of our main results are also considered and remarked, respectively.

• Journal of Ocean Engineering and Technology
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• v.25 no.5
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• pp.9-14
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• 2011

The divergence-free finite elements introduced in this paper are derived from Hermite functions, which interpolate stream functions. Velocity bases are derived from the curl of the Hermite functions. These velocity basis functions constitute a solenoidal function space, and the gradient of the Hermite functions constitute an irrotational function space. The incompressible Navier-Stokes equation is orthogonally decomposed into its solenoidal and irrotational parts, and the decoupled Navier-Stokes equations are then projected onto their corresponding spaces to form appropriate variational formulations. The degrees of the Hermite functions we introduce in this paper are bi-cubis, quartic, and quintic. To verify the accuracy and convergence of the present method, three well-known benchmark problems are chosen. These are lid-driven cavity flow, flow over a backward facing step, and buoyancy-driven flow within a square enclosure. The numerical results show good agreement with the previously published results in all cases.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.2
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• pp.56-63
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• 2005

Some methods have been presented to avoid collisions among satellites for satellite formation flying mission. The potential function method based on Lyapunov's theory is known as a powerful tool for collision avoidance in the robotic system because of its robustness and flexibility. During the last decade, a potential function has also been applied to UAV's and spacecraft operations, which consists of repulsive and attractive potential. In this study, the controller is designed using a potential function via sliding mode technique for the configuration of satellite formation flying. The strategy is based on enforcing the satellite to move along the gradient of a given potential function. The new scalar velocity function is introduced such that all satellites reach the goal points simultaneously. Simulation results show that the controller drives the satellite toward the desired point along the gradient of the potential function and is robust against external disturbances.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.351-354
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• 2006

This paper deals with the potential interferences between ground rod and counterpoise. The ground potential rise and coefficient of potential interference were measured by using the hemispherical water tank grounding simulator and calculated from CDEGS program as functions of the configuration and size of grounding electrodes and the distance between grounding electrodes. The ground potential un and potential interference coefficient strongly depend on the distance between grounding electrodes, the arrangement and size of grounding electrodes.