• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.10
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• pp.1420-1426
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• 2003

The stability of turbulent nonpremixed interacting flames is investigated in terms of nozzle configuration shapes and kind of fuels. Four nozzle arrangements - cross 5, matrix 8, matrix 9 and circle 8 nozzles - are used in the experiment. There are many parameters affecting flame stability in multi-nozzle flames such as nozzle separation distance, fuel flowrates and nozzle configuration etc. Key factors to enhance blowout limit are the nozzle configuration and the existence of center nozzle. Even nozzle exit velocity equal 204 m/s, flame is not extinguished when there is not a center nozzle and s/d=15.3∼27.6 in matrix-8 and circular-8 configurations. At these conditions, recirculation of burnt gas is related with stability augmentation. Fuel mole fraction measurements using laser induced fluorescence reveal lifted flame base is not located at the stoichiometric contour.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.250-258
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• 2018

Free Standing Hybrid Riser (FSHR) is comprised of vertical steel risers and Flexible Jumpers (FJ). They are jointly connected to a submerged Buoyancy Can (BC). There are several factors that have influence on the behavior of FSHR such as the span distance between an offshore platform and a foundation, BC up-lift force, BC submerged location and FJ length. An optimization method through a parametric study is presented. Firstly, descriptions for the overall arrangement and characteristics of FSHR are introduced. Secondly, a flowchart for optimization of FSHR is suggested. Following that, it is described how to select reasonable ranges for a parametric study and determine each of optimal configuration options. Lastly, numerical analysis based on this procedure is performed through a case study. In conclusion, the relation among those parameters is analyzed and non-dimensional parametric ranges on optimal arrangements are suggested. Additionally, strength analysis is performed with variation in the configuration.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.2
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• pp.57-64
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• 2008

The walls of art museums become the background of exhibits, and they form a unit space depending on the of each exhibit. In addition, the walls are configured and presented depending on the rhythm of space, or the structure of an axis. In this study, according to the axis composed for each unit space, the presentation methods of walls were classified as follows: The central type, the skewed type, the crossed type, the one-side corridor type, and the two-way corridor type. By analyzing visual configurations formed by the arrangement of each unit space, the value and the hierarchy of walls are discussed To analyze the classified types with the physical change of unit space, the factors of visual integration, connectivity, depth, and visual axis are compared, and various configurations of walls and space change are applied.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.7
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• pp.2356-2366
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• 1996

High-power electronic chips have been advanced to such an extent that the heat dissipation capability of a system design has become one of the primary limiting factors. Therefore, thermal design must be considered in the early stage of the electronic system development. In present paper, the results of an experimental study on the forced convection cooling are presented to evaluate cooling performance of an electronic cabinet which in generally used for telecommunication system. Temperatures and thermal resistances are applied to compare the heat transfer characteristics for various locations of a fan unit as well as various configuration of non-uniform powering modules. As a result, the optimal configuration of a fan unit and powering configuration is suggested for the effective thermal design of telecommunication system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.7
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• pp.1643-1653
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• 1994

To facilitate the manufacturing of dull using CNC grinding machine, the simulation of helical groove machining with given wheel profile and setting condition is necessary. Considering the wheel as a collection of thin disks, the flute configuration is predicted in a cross section perpendicular to the axis and the grinding wheel profile is also predicted to machine the desired helical groove with given setting conditions. Two programs for these processes are developed. Using programs interactively, the helical groove machining process can be predicted more accurately. By clarifying the geometrical relation between the shape of cutting edge and the flute configuration in the cross section which is perpendicular to drill axis, it becomes possible to predict the necessary cross sectional shape of wheel for desired drill cutting edge shape. Some factors for the software are considered concerning prediction of accuracy and computing time.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.8
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• pp.437-443
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• 2003

In this paper an expert system is developed to decide the resetting area of protective devices in power transmission systems. A configuration change in power transmission networks from a substation extension such as new line or bus addition need resetting of protective devices around the point of configuration changes. To find the resetting area in complex power system is very difficult, especially when the distance protective relays are considered to be reset. The proposed expert system, in this paper to find the resetting area has many rules based on the changes of fault currents and apparent factors from the power system alteration. It solves the problem to find relay resetting area using the network information in the database and the rule-base. The case study shows a result of the problem to find relay resetting area in KEPCO system when there is any configuration change.

• Korean Institute of Interior Design Journal
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• v.17 no.6
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• pp.137-142
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• 2008

Since mid 1990s, the domestic market in Korea has been changing drastically especially in the field of discount stores. The competition among this market is more severe and the consuming pattern is also changed. This study is to examine the correlation between the customer's circulation and the spatial configuration by using Space Syntax and VMD pattern through the MD plan of each floor in Discount store. Throughout this study, it tries to find out the Quantitative analysis among three factors - the customer's circulation, spatial configuration and VMD investigation. The pattern of customer's circulation appears differently according to the identity of customer and store layout, but with the result, customer's circulation system is in accordance with the floor layout in the store. In result of the study, the circulation of the customer was found to have a close relationship with spatial structure that is composed by the MD pattern in a discount store in the area of food section. Also, the circulation system in the rest area except food section is more affected by the VMD pattern rather than spatial structure.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.146-154
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• 2008

The study aims to find out the changing aspects of contemporary Korean libraries so called public in terms of their spatial characteristics. In so doing, it analysed 16 recently built libraries by using the spatial depth defined in the Space Syntax theory. As the result, it could be said that the libraries were planned and designed well reflecting the world wide trend as a public institution such as an open plan, easy access, new functional spaces, and so on. It could be also said, however, that there was no difference between the previous libraries and the recent ones when the actual usage is considered. It means that the architectural attempts have been made to plan an 'open, public library', especially in terms of the spatial configuration, whereas the way of management has not been changed at all for some reasons such as the lack of staffs, security and so on. Therefore, it can be seen that the depth, one of the most important factors in the recognition of the spatial configuration, is more deepened as a form of the liner structure in the spatial configuration.

• Journal of Korea Multimedia Society
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• v.16 no.4
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• pp.472-482
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• 2013

This paper proposes a wireless LAN topology configuration method for enhancing indoor location-awareness and improving network performance simultaneously. We first develop four objective functions that yield objective goals significant to the optimal design of a wireless LAN topology in terms of location-awareness accuracy and network performance factors. Then, we develop metaheuristic algorithms such as simulated annealing, tabu search, and genetic algorithm that examine the proposed objective functions and generate a near-optimal solution for a given objective function. Finally, four objective functions and metaheuristic algorithms developed in this paper are exploited to evaluate and measure the performance of the proposed wireless LAN topology configuration method.

• Korean Institute of Interior Design Journal
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• v.16 no.6
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• pp.197-204
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• 2007

In the spatial configuration of room-to-room art museums, openings and walls are important physical factors, and openings are a medium for connecting spaces. Also, by spatially composing walls and openings, spaces can be connected visually and physically, and movements and directions may vary depending on the location or size of walls and openings. In this study, 5 museums are investigated: Sainsbury Wing in London, Gemaldegalerie In Berlin, Alte Pinakotkek in Munich, Neue Pinakothek in Munich, and Staatsgalerie Stuttgart in Stuttgart. Using DepthMap program, the characteristics of visual-spatial composition of each museum are derived by comparing the Connectivity, Visual integration, and Isovist maximum radial. From an analysis of spatial distribution, a relationship with visibility is investigated. The results of this study showed that the combination of visual axial lines affect the spatial configuration of the room-to-room museums. Depending on the location of opening, the museums can be classified as follows: 1) Museums with the 1st visual axial line and the 2nd and 3rd auxiliary visual axial lines ; 2) museums with several equal visual axial lines; and 3) museums with only center axial line.