• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.65-68
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• 2008

In this study, in order to improve luminous efficacy of AC-PDP, the new facing discharge structure has been suggested. The suggested structure has tilted facing electrode. It shows lower discharge current, higher luminance and luminous efficacy compared with those of reference structure with coplanar electrode structure.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.104-107
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• 2009

In order to improve discharge characteristics in AC PDP, we suggest FDFA (Facing Discharge Front plate Address Electrode) structure. By adopting both long facing discharge electrodes and address electrodes in front plate, the FDFA structure make it possible to gain a high luminance, low power consumption, and a high luminous efficiency.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1674-1680
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• 2002

An experimental study was made of a large-scale vortical structure over a backward-facing step. The Reynolds number based on the step height was R $e_{H}$ =33,000. To recognize the large-scale vortex, three components of velocity were measured. The measurements were performed in the recirculation zone (x/H=4.0) and the reattachment zone(x/H=7.5). To measure the wall pressure fluctuations in a turbulent flow over a backward-facing step, a 32-channel microphone array was installed beneath the wall in the streamwise and spanwise directions. From the measured pressure field, the size of large-scale vortex was obtained. As a detailed study, a conditionally-averaging technique was employed to characterize the coherent structure of the large-scale vortex. To see the relationship between the flow field and the relevant spatial mode of the pressure field, the spatial box filtering (SBF) was examined. A cross-correlation between velocity and pressure fluctuations was performed to identify the structure and the length scale of the large-scale vortex.x.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.1
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• pp.54-63
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• 1997

The purpose of this study is to analyse deformation properties by carrying out of flexure experimentations after fabricating polymer concrete sandwich panels which are composed of the polymer concrete in facing and expanded polystyren in cores, and to provide the basic data necessary to design, fabricate and operate the structure using these polymer concrete sandwich panels The analysed result of this study is summarized as follows. 1. The result of experiment on flexural deflection indicated that the thicker the thickness of both cores and facing of the polymer concrete sandwich panels, the smaller the deflection but the larger the ultimate shear force. In addition, it was also shown that the thicker the thickness of these cores and facing, the smaller the increasing rate of the deflection with the increase of load. 2. The breaking shape of polymer concrete sandwich panels by experiment on flexure was different according to the thickness of facing. When the facing was 5mm in thickness, it was the flexure while it was the flexure and shear failure when the facing was 5mm in thickness. As a result, it seems that the thickness of the facing has a great effect on failure. 3. There were induced not only the related formula between load, deflection and deformation according to the thickness of cores and facing on the basis of the flexure experiment, but also formula between load, horizontal displacement, Then, it seems that it will be possible to estimate the above elements by using these related formulas.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.359-366
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• 2009

The present paper analyzes and discusses the effect of facing system and staged construction in GRS (geosynethetic reinforced soil) walls for railway structures throughout various case analyses. The result shows that postconstruction facing system by staged construction procedures is more advantageous for railway structure construction than preconstruction and simultaneous construction facing system with reinforced soil.

• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.361-368
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• 2002

The valley forests located at the east-facing slope and the west facing slope in Hambaeksan area were studied to investigate forest structure in relation to aspect and altitude of the slope. There was little difference in density. mean DBH and basal area of the tree layer between east-facing slope and west-facing slope. The importance percentages of Tilia amurensis and Betula costata in west-facing slope were higher than those in east-facing slope. However, the importance percentages of Quercus mongilica and Fraxinus rhynchophylla in the west facing slope were lower than those in east-facing slope. Species diversity of the west-facing slope was 1.415 and that of the east-facing slope was 1.328. Elevation trends were also found for forest structure. As elevation Increased basal area and mean height of the tree layer decreased in both of east-facing slope and west-facing slope. There was a tendency that number of species, species diversity and evenness decreased with increasing elevation. The importance percentage of Quercus mongolica increased with increasing elevation while those of Betula costata and Maackia amurensis decreased. The result of cluster analysis for the tree and subtree layer indicated that the studied forests were classified into the mixed forest community of broad-leaved tree species at west-facing slope and the low and middle elevation belts of east-facing slope and Quercus mongolica community at the high elevation belt of east-facing slope. Quercus mongolica was significantly and positively correlated with Symplocos chinensis for. pilosa, Acer tschonoskii var. rubripes and deutzia glabrata. Betula costata was significantly and negatively correlated with Quercus mongolica and Acer pseudo-sieboldianum.

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.139-146
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• 2006

An experimental study was performed to evaluate the effects of surface coating and an enhanced insulation structure on the downward facing boiling process and the critical heat flux on the outer surface of a hemispherical vessel. Steady-state boiling tests were conducted in the Subscale Boundary Layer Boiling (SBLB) facility using an enhanced vessel/insulation design for the cases with and without vessel coatings. Based on the boiling data, CHF correlations were obtained for both plain and coated vessels. It was found that the nucleate boiling rates and the local CHF limits for the case with micro-porous layer coating were consistently higher than those values for a plain vessel at the same angular location. The enhancement in the local CHF limits and nucleate boiling rates was mainly due to the micro-porous layer coating that increased the local liquid supply rate toward the vaporization sites on the vessel surface. For the case with thermal insulation, the local CHF limit tended to increase from the bottom center at first, then decrease toward the minimum gap location, and finally increase toward the equator. This non-monotonic behavior, which differed significantly from the case without thermal insulation, was evidently due to the local variation of the two-phase motions in the annular channel between the test vessel and the insulation structure.

• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.37-47
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• 2011

This paper describes the stability evaluation of reinforced earth wall with steel framed-facing based on field test. The reinforced earth wall with steel framed-facing is composed of wall facing, reinforcement and backfill soil. The wall facing is assembled by steel frames and the aggregates are filled in that. The reinforcement is steel strip type based on bearing resistance. Field test is conducted to evaluate for two separate sections and the measurement is conducted according to construction elapsed time of structure for earth pressure, horizontal displacement of wall facing and reinforcement strain. The evaluation results show that the measured earth pressure is less than theoretical earth pressure due to dispersion effect of earth pressure by the applied reinforcement. Also, the horizontal displacement of wall facing satisfied a empirical criteria and the measured strain of reinforcement had nearly no effect on stability of structure. Therefore, the reinforced earth wall with steel framed-facing has a structural stability and it can be commonly used in field.

• Korean Journal of Environment and Ecology
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• v.16 no.4
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• pp.449-456
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• 2003

The valley forests at Baraebong area, Jirisan National Park were studied to investigate forest structure of tree, subtree and shrub layers in relation to aspect and altitude of the slope. Density and basal area of the tree layer in the north-facing slope were greater than those in the south-facing slope. As elevation increased, basal area of the tree layer decreased in north-facing slope. The impotance percentage of Quercus mongolica increased with increasing elevation while those of Quercus serrata and Pinus densiflora decreased. Species diversity of the north-facing slope was 1.307 and that of the south-facing slope was 1.114. There was a tendency that number of species, species diversity and evenness decreased with increasing elevation. The result of cluster analysis for the tree and subtree layer indicated that the studied forests were classified into Quercus senrraa-broad-leaved tree species community at the low and middle elevation belts of the south-facing slope, Quercus mongolika-broad-leaved tree species community at the high elevation belt of the south-facing slope, the middle and high elevation belts of the north-facing slope and top area, and Pinus densiflora-Quercus mangolica community at the low elevation belt of the north-facing slope. There were significantly positive correlations in the importance percentages among Carpinus laxiflora, Quercus serrata, Styrax obassica and Linden obtuiloba, and among Castanea crenata, Rhodndendron schippen-bachii and Vibntnum erosum.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.124-130
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• 2004

The valley forests at Songgyesa-Motbong-Wolhatan Area in Deogyusan National Park were studied to investigate forest structure in relation to aspect and altitude of the slope. Density, mean DBH, mean height and basal area of the tree and subtree layers in the north-facing slope were greater than those in the south-facing slope. The impotance percentage of Fraxinus mandshurica and Carpinus cordata increased with increasing elevation while those of Quercus serrata and Quercus aliena decreased. Species diversity of the north-facing slope was 1.362 and that of the south-facing slope was 1.242. There was a tendency that number of species and species diversity decreased with increasing elevation. The result of cluster analysis for the tree and sub-tree layer indicated that the studied forests were classified into broad-leaved tree species community at the low and middle elevation belts of the south-facing slope and the north-facing slope, Fraxinus mandshurica-Quercus mongolica community at the high elevation belts of the south-facing slope and the north-facing slope and Quercus mongolica community at the top area. There were significantly positive correlations in the importance percentages among Quercus serrata, Betuzo davurica and Tilia amurensis. Carpinus laxiflora was significantly correlated with Cornus controversa, Tilia amurensis and Lindera obtusiloba. There was significantly negative correlation between Fraxinus mandshurica and Pinus densiflora.