• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.28-33
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• 2023

In this study, computational fluid dynamics was used to analyze the flow bias generated as air supplied by a fan passes through ducts, piping, and a coal separation screen. The flow bias of the air flow is mostly caused by the spatial characteristics of the fan volute and duct, and the internal baffle and the coal separation screen at the outlet cause strong pressure losses that dampen the flow bias. ANSYS CFX was used for computational fluid dynamics, and since the baffle and the coal separation screen are shaped like perforated plates with many small holes uniformly distributed, actual modeling for analysis was not possible. Therefore, the Porous Loss Model was applied. The evaluation of the flow bias was analyzed based on the velocity distribution of the Porous Loss Model at the outlet surface of the coal separation screen obtained from the computational fluid dynamics results.

• Journal of Families and Better Life
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• v.26 no.5
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• pp.195-209
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• 2008

The purpose of this study was to provide basic information about design guidelines of activity areas in elderly nursing facilities. For the study, the activity areas of 44 facilities in Korea were investigated to categorize their spatial compositions and forms, and then a case study about 19 facilities was conducted to analyse their hierarchical characteristics. The results of the study were as follows: First, the major type of spatial composition among 44 research facilities was concentration, but compartment type was the main among unit-care facilities. By the year, all the types of spatial composition were evenly distributed during recent five years, while concentration type was about 40% before 2003. Second, the major form of activity areas was hall or corridor extension for large group. But there was more alcove or separation form among small group spaces. Third, in the case analysis about hierarchical characteristics, hall and corridor extension form met the requirements of accessibility and openness of public and semi-public areas. On the other hand, separation form had a problem in satisfying both requirements. The semi-private areas, which were around the elderly bedrooms and the elderly were able to watch activities in, were not sufficient in many facilities. Fourth, the division of public and semi-public area was mainly by furniture, and the individuality of semi-private area was defined by dead-end place and corner seats of the window or the corridor. The diversity of semi-private area was likely to be appeared in connection or distribution type. On the basis of the results, the basic design guidelines for activity areas in elderly nursing facilities could be suggested as follows: On the whole, connection or distribution type in spatial composition is more efficient for hierarchical flow than concentration or compartment type is, especially in Korean facilities having many elderly residents per floor. In detail, the design of public and semi-public area should be focused on their openness and accessibility. The recommended forms of activity areas were hall or corridor extension in public area, and living room, corridor extension, or large corridor in semi-public area to effectively function as large or small group spaces. In semi-private areas, the spatial diversity and individuality should be considered.

• Journal of the Korean housing association
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• v.20 no.5
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• pp.61-72
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• 2009

The purpose of this study was to examine how the interface between "place of work" and "place of living" in the housing sphere has changed, and to understand its social background. During the korean modernization period, changes in economic structure toward industry has an influence on many aspects of modem life in addition to occupations. The traditional mixing of heterogeneous activities in the home-such as between reproduction and household affairs, first changed into a coexistence of two spaces with different functions within the boundaries of home, and finally into a spatial separation between functions in an urban dimension. As a result of this process, the primary role of the modem home is as a place for relaxation without work. One important kind of home, in which a retail shop is integrated with it, was researched as a transitional form. Its spatial layout showed a various combined usage of both spaces. In conclusion, changes in relevant macro-social aspects are very concretely reflected m the function and spatial organization of the home.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.359-364
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• 2005

Spatial autocorrelation was applied to microgeographic variations of Sasa borealis populations in Korea. Separate counts of each type of join (combination of genotypes at a single locus) for each allele, and for each distance class of separation, were tested for significant deviation from random expectations by calculating the Standard Normal Deviation. Moran's I was significantly different from the expected value in 25 of 150 cases $(16.7\%)$. Seven of these values $(4.7\%)$ were negative, indicating genetic dissimilarity among pairs of individuals in the ten distance classes. Populations of S. borealis are small in Korea, and are distributed with occasional cutting of seed-bearing stems used for sieves. Thus, artificial disturbance may contribute to the fact that the S. borealis population of Jirisan is unusual in lacking spatial genetic structure.

• Journal of the Korean Home Economics Association
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• v.46 no.8
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• pp.135-147
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• 2008

This study was to identify the spatial and functional characteristics of kitchen and utility space plan in apartment housing. For this purpose, spatial arrangement and function of kitchen and utility space were analyzed according to the size of apartment unit. The results of this study were as follows; 1) The level of spatial separation among living room, dining room, and bedroom is higher in large-sized apartment. And diverse plans were applied for the kitchen of large-sized apartment. 2) To find out functional characteristics of kitchen space, furniture arrangement was analyzed. The I-type kitchen furniture is dominant for small-sized and medium-small apartment, and L-type furniture for medium-large and large sized apartment. 3) For most of the unit plans utility space is located on the balcony outside the kitchen. 4) Sub-kitchen and laundry are major function of utility space, but in case of balcony extention, the function of utility space is minimized. Recent plans for apartment housing shows various spatial arrangement and functions for kitchen and utility space.

• Earthquakes and Structures
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• v.15 no.2
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• pp.193-202
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• 2018

This paper studied the probability of pounding occurred between decks and abutments of a long span high-pier continuous rigid fame bridge subjected to ground motions with local soil effect. A pounding probability analysis methodology has been proposed using peak acceleration at bedrock as intensity measure (IM) for multi-support seismic analysis. The bridge nonlinear finite element (FE) models was built with four different separation distances. Effect of actual site condition and non-uniform spatial soil profiles on seismic wave propagating from bedrock to ground surface is modelled. Pounding probability of the high-pier bridge under multi-support seismic excitations (MSSE) is analyzed based on the nonlinear incremental dynamic analysis (n-IDA). Pounding probability results under uniform excitations (UE) without actual local site effect are compared with that under MSSE with site effect. The study indicates that the required design separation length between deck and abutment under uniform excitations is larger than that under MSSE as the peak acceleration at bedrock increases. As the increase of both separation distance between deck and abutment and the peak acceleration, the probability of pounding occurred at a single abutment or at two abutments simultaneously under MSSE is less than that under UE. It is of great significance considering actual local site effect for determining the separation distance between deck and abutment through the probability pounding analysis of the high-pier bridge under MSSE.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.426-432
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• 2004

Large-Eddy Simulation (LES) is applied for the simulation of compressible flat plate boundary with Reynolds number up to 5 X 10$^{5}$ . Numerical examples include shock/boundary layer interaction and boundary layer transition, aiming future application to the analysis of transonic fan/compressor cascades. The present LES code uses hybrid com-pact/WENO scheme for the spatial discretization and compact diagonalized implicit scheme for the time integration. The present code successfully predicted the bypass transition of subsonic boundary layer. As for supersonic turbulent boundary layer, mean and fluctuation velocity of the attached boundary, as well as the evolution of the friction coefficient and the displacement thickness both upstream and downstream of the separation region are all in good agreement with experiment. The separation point also agreed with the experiment. In the simulation of the shock/laminar boundary layer interaction, the dependence of the transition upon the shock strength is reproduced qualitatively, but the extent of the separation region is overpredicted. These numerical examples show that LES can predict the behavior of boundary layer including transition and shock interaction, which are hardly managed by the conventional Reynolds-averaged Navier-Stokes approach, although there needs to be more effort before achieving quantitative agreement.

• Journal of Photoscience
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• v.6 no.3
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• pp.91-96
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• 1999

Zeolites and microporouos materials continue to attract attention as novel hosts for photochemical reactions. Zeolities are attractive because of their ability to selectivity exchange and incorporate species within the void spaces and interconnecting channels, providing a spatial arrangement of molecules. Our research has primarily focused on intrazeolitic electron transfer from excited Ru(bpy)32+ in supercages of zeolite Y to a series of bipyridinium ions. In the Ru(bpy)32+ viologen-zeolite Y samples, the slowing of the back electron transfer from the bipyridinium radical cation to Ru(bpy)32+ allows for charge propagation via self exchange between diquat molecules. This provides an opportunity for permanent charge separation. When the migrating charge on the diquat radical within the zeolite reaches the surface, it can be transferred to a neutral viologen (PVS) in solution, resulting in permanent charge separation. The advantage of long-lived charge separation can be exploited for useful chemistry if suitable catablysts can be assembled on the zeolities. We have studied Ru(bpy)2 as water oxdiation catalysts. We have demonstrated that synthesis of RuO2 fibers on a zeolite via thermal decomposition of Ru3(CO)12 leads to the most active water decomposition catalyst reported to date. Because of the extensive interest of photochemical water reduction to H2, much is known about catalytic systems usin gone electron catalyst, and even more importantly, that no reaction of viologen occurred with H2 over this catalyst. The present challenge is to incorporate all these elements of the system into an architecture and we are examining zeolite membranes for this purpose.

• Journal of Mechanical Science and Technology
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• v.16 no.3
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• pp.363-375
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• 2002

The effect of the electromagnetic force (or Lorentz force) on the flow behavior around a circular cylinder is investigated by computation. Two-dimensional unsteady flow computation for Re=10$^2$is carried out using a numerical method of finite difference approximation in a curvilinear body-fitted coordinate system by solving the momentum equations including the Lorentz force as a body force. The effect of spatial variations of the Lorentz forcing region and forcing direction along the cylinder circumference is investigated. The numerical results show that the Lorentz force can effectively suppress the flow separation and oscillation of the lift force of circular cylinder cross-flow, leading to reduction of drag.

• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.409-412
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• 2001

Poly(p-tert-butyltrimethoxymonopropyloxycalix[4]arene-methylsiloxane) (TBCX-MS) has been prepared and used as a stationary phase in isothermal capillary gas chromatographic separation of some positional isomers. Retention factors (k) and separatio n factors $(\alpha)$ for the isomers were measured and compared with those on poly(p-tert-butyl-dimethoxydipropyloxycalix[4]arene-tetramethyldisiloxane) (TBCX-TMDS), poly(dimethoxydipropyloxycalix[4]arenetetramethyl-disiloxane) (CX-TMDS). Most of the isomers investigated are well resolved on TBCX-MS. Retention of all the compounds decreases on the three phases in the order, TBCX-TMDS ${\geq}$ TBCX-MS > CX-TMDS. Similar retention values on TBCX-TMDS and TBCX-MS seem to indicate that retention property of the two phases is not significantly affected by the spatial position of the calixarene moiety.