• Korean Journal of Mathematics
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• v.25 no.2
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• pp.211-214
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• 2017

In this paper we consider a triple of distinct points in the boundary of quaternionic hyperbolic space and detect where these points are by using the quaternionic triple product.

• Bulletin of the Korean Mathematical Society
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• v.58 no.3
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• pp.721-727
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• 2021

The convex hull of a generic triple of boundary points has non-zero finite volume in complex hyperbolic 2-space.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.81-89
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• 2010

The problem of defining the relationship between interior space and exterior envelope of a building has long been a challenging task in the field of architecture throughout its history. This research chronologically reviews some of the important turning points in various schools of thoughts concerning construction of exterior envelope, with focus on how they influenced and altered the formation of our interior environment. This research also stipulates on how technological advance in the late 20th century laid grounds for a new type of interior-exterior relations in architecture through creation of flexible and ambiguous boundary conditions. The focus of this qualitative research will be on contemporary works of Japanese architects Toyo Ito, SANAA, and related group of architects who address the issues of transparency, flexible interior layout, buffer zones, structural facade, and neutralized (homogeneous) space that produces spatial quality of non-linear, non-hierarchical, and de-materialized space as a direct alternative to modern principles of space making.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.8
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• pp.670-676
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• 2007

A comparative study on ground boundary conditions for the airfoil in ground effect has been carried out. The objective of the present study is to clarify effects of the ground boundary conditions so that it will be helpful to analyse results of wind tunnel tests using the fixed ground board or the image method. A low Mach number preconditioned Navier-Stokes solver using the overlap grid method has been applied. It has been turned out that results with the symmetric boundary condition are almost the same to those with the moving boundary condition. Results with the fixed ground boundary show discrepancy to those with the moving boundary condition when flow separation on the ground board takes place.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.2
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• pp.199-208
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• 2008

In this paper, to analyze the initial valued non-homogeneous elastic half space by the scaled boundary analysis, the infinite element approach was introduced. The free surface of the initial valued non-homogeneous elastic half space was modeled as a circumferential direction of boundary scaled boundary coordinate. The infinite element was used to represent the infinite length of the free surface. The initial value of material property(elastic modulus) was considered by the combination of the position of the scaling center and the power function of the radial direction. By use of the mapping type infinite element, the consistent elements formulation could be available. The performance and the feasibility of proposed approach are examined by two numerical examples.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.71.3-71.3
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• 2019

Previously we developed a method of coronal force-free field construction using vector potentials. In this method, the boundary normal component of the vector potential should be adjusted at every iteration step to implement the boundary normal current density, which is provided by observations. The method was a variational method in the sense that the excessive kinetic energy is removed from the system at every iteration step. The boundary condition imposing the normal current density, however, is not compatible with the variational procedure seeking for the minimum energy state, which is employed by most force-free field solvers currently being used. To resolve this problem, we have developed a totally new method of force-free field construction. Our new method uses a unique magnetic field description using two scalar functions. Our procedure is non-variational and can impose the boundary normal current density exactly. We have tested the new force-free solver for standard Low & Lou fields and Titov-Demoulin flux ropes. Our code excels others in both examples, especially in Titov-Demoulin flux ropes, for which most codes available now yield poor results. Application to a real active region will also be presented.

• International Journal of Aeronautical and Space Sciences
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• v.6 no.1
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• pp.1-7
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• 2005

The inlet boundary condition of computations about the supersonic turbine flow is commonly applied as far-field inlet boundary condition with specified velocity. However, the inflow condition of supersonic turbine is sometimes affected by the shocks or expansion waves propagated from leading edges of blade. These shocks and expansion waves alter the inlet boundary condition. In this case, the inlet boundary condition can not be specified Therefore, in this paper, numerical analyses for three different inlet conditions - fa-field inlet boundary condition, inlet boundary condition with a linear nozzle and inlet boundary condition with a converging-diverging nozzle - have been performed and compared with experimental results to solve the problem. It is found that the inlet condition with a linear nozzle or a converging-diverging nozzle can prevent changing of inlet boundary condition, and thus predict more accurately the supersonic flow within turbine cascade than a far-field inlet boundary condition does.

• Journal of the Korean Mathematical Society
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• v.43 no.6
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• pp.1143-1158
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• 2006

We consider the projectivization of Minkowski space with the analytic continuation of the hyperbolic metric and call this an extended hyperbolic space. We can measure the volume of a domain lying across the boundary of the hyperbolic space using an analytic continuation argument. In this paper we show this method can be further generalized to find the volume of a domain with smooth boundary with suitable regularity in dimension 2 and 3. We also discuss that this volume is invariant under the group of hyperbolic isometries and that this regularity condition is sharp.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.69.2-69.2
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• 2019

To construct a coronal force-free magnetic field, we must impose the boundary normal current density (or three components of magnetic field) as well as the boundary normal field at the photosphere as boundary conditions. The only method that is known to implement these boundary conditions exactly is the method devised by Grad and Rubin (1958). However, the Grad-Rubin method and all its variations (including the fluxon method) suffer from convergence problems. The magnetofrictional method and its variations are more robust than the Grad-Rubin method in that they at least produce a certain solution irrespective of whether the global solution is compatible with the imposed boundary conditions. More than often, the influence of the boundary conditions does not reach beyond one or two grid planes next to the boundary. We have found that the 2D solenoidal gauge condition for vector potentials allows us to implement the required boundary conditions easily and effectively. The 2D solenoidal condition is translated into one scalar function. Thus, we need two scalar functions to describe the magnetic field. This description is quite similar to the Chandrasekhar-Kendall representation, but there is a significant difference between them. In the latter, the toroidal field has both Laplacian and divergence terms while in ours, it has only a 2D Laplacian term. The toroidal current density is also expressed by a 2D Laplacian. Thus, the implementation of boundary normal field and current are straightforward and their effect can permeate through the whole computational domain. In this paper, we will give detailed math involved in this formulation and discuss possible lateral and top boundary conditions and their meanings.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.26-34
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• 2005

The systematic way of the boundary thought in Buddhism, when applied to the principles of building, determines certain forms to certain temples, and organizes their topological boundary concept structure - the continuous experience of the visitor from his/her entry bridge(connecting), through the main temple gate(neighbourhood), pavilion gate(including), stairs(continuance), to the arrival at the pavilion of the god of a mountain(spiral), which reconstitutes the Buddhist boundary symbolism and philosophy. The topological boundary spaces of temples are an architectural manifestation of Buddhism's Mahayana boundary concept aspects, whose object is to play a productive and active role in the enlightenment of people, serving the very basic end of the religion. The disciplined topological boundary spaces of the temple, as a reification of the boundary symbolisms of Buddhist topological cosmology, corresponds to Buddha-Ksetra, the highest state of existence in the universe. Visitors to the temple are invited to participate in the world of abundant Buddhist boundary concept symbols, and through this process, is enabled to elevate oneself to the transcendent topological boundary world and have a simulated experience of liberation.