• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.499-503
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• 2002

This work focuses on eliminating tiny particles from the coolant in a nuclear pipe line by using a permanent magnet on the exterior surface of the pipe. This method have some merits compared with the many applied methods and is expected to be applied to most of the pipe lines in the nuclear plant. For instance in this method, a ring is attached to the exterior surface of the pipe, so that it does not affect the inflows directly. Further, the cost needed in the initial build-up of the facility is low.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.25-31
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• 2001

The theoretical modeling to predict the modulus of elasticity by the shape memory effect of dispersed particles in a metal matrix composite was studied. The modeling approach is based on the Eshelbys equivalent inclusion method and Mori-Tanakas mean field theory. The calculation was performed on the TiNi particle dispersed Al metal matrix composites(PDMMC) with varying volume fractions and prestrains of the particle. It was found that the prestrain has no effect on the Yonugs modulus of PDMMC but the volume fraction does affects it. This approach has an advantage of definite control of Youngs modulus in PDMMCs.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.626-629
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• 2008

In this study, a geothermal power generation system using the Kalina cycle was investigated by the simulation method. The Kalina cycle system can be used for the utilization of a low-temperature heat sources such as geothermal and industrial waste heat that are not hot enough to produce steam. The sea/river water can be considered as a cooling media. A steady-state simulation model was developed to analyze and optimize its performance. The model contains a turbine, a pump, an expansion valve and heat exchangers. The turbine and pump were modelled by an isentropic efficiency, while a condenser, an evaporator and a regenerative heat exchanger were modeled by UA-LMTD method with a counter-flow assumption. The effect of the ammonia fraction at the separator inlet on the cycle performance is investigated in detail.

• The KSFM Journal of Fluid Machinery
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• v.6 no.4 s.21
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• pp.45-49
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• 2003

This work focuses on eliminating tiny particles from the coolant in a nuclear pipe line by using a permanent magnet on the exterior surface of the pipe. This method have some merits compared with the currently applied methods and is expected to be applied to most of the pipe lines in the nuclear plant. For instance in this method, a ring is attacked to the exterior surface of the pipe, so that it does not affect the inflows directly. Further, the cost needed in the initial build-up of the facility is low.

• Journal of the Korean Society of Combustion
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• v.4 no.1
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• pp.117-129
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• 1999

A method for the mixing augmentation of the transverse injection of fuel in a Scramjet combustor is suggested. Based on the fact that the main factor controlling the mixing characteristics in transverse injection is the effective back-pressure (the pressure around the injection hole) it is tried to make a flow expansion near the injection port in order to reduce effective back-pressure. A three dimensional Navier-Stokes code adopting the upwind method of Roe#s flux difference splitting scheme is used. The k-w SST turbulence model turbulence model is used to calculate the turbulent viscosity. It is shown that the reducing of the effective back-pressure make it possible to increase the penetration distance and to increase the mixing rate without excessive losses of stagnation pressure. Also, it is shown that the streamwise vorticity generated by baroclinic torque has great influences on the mixing process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.04a
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• pp.156-163
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• 1997

Recently, attempts have been made to be join ceramics to metals in order to make up for the brittleness of ceramics. The difference in the coefficients of linear expansion of the two materials joined at high temperature will cause residual stress, which has a strong influence on the strength of the bonded joints. In this paper, the residual stress distribution and stress intensity factors of the ceramic/metal bonded joints were analyzed by 2-dimensional elastic boundary element method. Fracture toughness tests of ceramic/metal bonded joints with an interface crack were carried out. So the advanced method of quantitative strength evaluation for ceramic/metal bonded joints is to be suggested. Fracture surface and crack propagation path were observed using scanning electron microscope.

• Journal of electromagnetic engineering and science
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• v.18 no.4
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• pp.248-253
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• 2018

An electromagnetic boundary-value problem of a tapered rectangular waveguide is rigorously solved based on eigenfunction expansion and the mode-matching method. Scattering parameters of the tapered rectangular waveguide are represented in a series form and calculated in terms of different rectangular waveguide combinations. Computation is performed to analyze reflection and transmission characteristics. Conductor loss by surface current density is also calculated and discussed.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.152-160
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• 2011

Contemporary architecture pursues new method of Interpretation of Non-linear space as digital media appears. As various materials and new methods can be used due to developments in science and expansion of thinking, contemporary architectural color developed extensive possibilities. It means not only the change of drawings, method of architectural product and materials but also the change of value system for architectural space. Thus the purpose of this paper is to suggest interpretation of space applied by color structure, and this point of view was based on the three elements of color perception which are light source, reflector, and observer. According to this categorization, architectural color of exterior color, layer color and interaction color are explained via examples of colors recently used on the contemporary architectures. In summary, contemporary architecture can be explained by Non-construction space interpretation for intrinsic complex meanings. Therefore, it can be explained as moving space, collage, by picturesque space, moving blur color and emptiness of color. This pursues various point of views for space interpretation, therefore it can be developed to the identity of strengthening architectures' design concept.

• Journal of Korea Multimedia Society
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• v.23 no.3
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• pp.476-482
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• 2020

In this paper, we propose a block-based modularity architecture design method for distributed machine learning. The proposed architecture is a block-type module structure with various machine learning algorithms. It allows free expansion between block-type modules and allows multiple machine learning algorithms to be organically interlocked according to the situation. The architecture enables open data communication using the metadata query protocol. Also, the architecture makes it easy to implement an application service combining various edge computing devices by designing a communication method suitable for surrounding applications. To confirm the interlocking between the proposed block-type modules, we implemented a hardware-based modularity application system.

• Journal of the Korean housing association
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• v.13 no.6
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• pp.121-131
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• 2002

The rebuilding method for old apartment housing blocks has merits of providing new buildings and larger private living spaces. However, it causes many serious urban problems, such as shortage of infrastructure capacity, traffic congestion, reduction of building life, and deterioration of open space quality. Nowadays, remodeling is accepted as a way of overcoming such negative effects of the rebuilding method. This study focuses on the various techniques of remodeling. The results of this research are as follows; First, old apartment blocks provide poor level of service in general, so they have problems of bad accessibility, deterioration of facilities, and degraded landscape. In many cases, there is a hindrance from walking freely and security problem due to illegal privatization of public spaces. Second, various remodeling techniques are required to meet residents' different needs. The residents of apartment housing value private space above public space, and show low level of willingness to pay cost for remodeling. Third, based on these findings, some remodeling techniques are suggested - integration of a space to another, expansion of spaces, connection of spaces, reuses of roofs and walls, relocation and renovation of paths between buildings, and so on.