• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.66.2-66.2
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• 2013

In this study, we present a pore-selection technique to estimate the size of pore. The estimation of the size of pore is important to examine the temporal evolution of size itself and corresponding intensity. The size of pore is typically estimated by applying the intensity threshold technique to the fixed box which contains the entire pore. The typical method has disadvantages in the following circumstances; there are small features near the pore or the image has low spatial resolution. In the former, it is difficult to define a box containing the pore only, excluding the small features near the pore. In the latter, the background and threshold intensity are insignificant due to the insufficient number of pixel in the box. To avoid these difficulties, we use a pore-selection technique which is simply based on the measurement of distances from the pore center. In addition, we will discuss the advantage of the technique for the imaging spectrograph data like the NST FISS.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.109-112
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• 1987

This experiment was to study the effects of soil compaction and artificial pore space on the shoot density of tall fescue (Festuca arundinacea Schreb.). Tall fescue subjected to compaction treatments with control, 10, 20 and 40 kg power roller, used for two times bi-weekly during six months. Artificial pore space treatments were control, 13.5, 37.5 and 84.5% at 0-lOcm depth, respectively. 1. Soil compaction increased soil hardness and soil bulk density.2. Compaction level of lOkg (soil hardness 2.5kg/$cm^3$) showed the highest shoot density than that of other treatments. 3. Artificial pore space was positive significant correlated (p<0.01) with shoot density. 4. When over the 37.5% of total pore space could be mainternance for high shoot density after the soil compacted.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.575-580
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• 2010

In this work, the electrophoretic motion of dsDNA molecule represented by a polymer through an artificial nano-pore in a membrane is simulated using the numerical method combining the lattice Boltzmann and Langevin molecular dynamic method. The polymer motion is represented by Langevin molecular dynamics technique while the fluid flow is taken into account by fluctuating lattice-Boltzmann method. The hydrodynamic interactions between the polymer and solvent in a confined space with a membrane having a hole are considered explicitly through the frictional and the random forces. The electric field intensity over the space is obtained from a finite difference method. Initially, the polymer is placed at one side of the space, and an electric field is applied to drive the polymer to the other side of the space through the nano-pore. In future, we plan to study the effect of the polymer size and the electric field on the electrophoretic velocity.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.71.2-71.2
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• 2014

For better understanding of the physics of pores, we have investigated horizontal and vertical motions of plasma in a pore obtained on 2013 August 24 by using high time and spatial resolution data from the Fast Imaging Solar Spectrograph (FISS) of the 1.6 meter New Solar Telescope (NST). We infer the LOS velocity by applying the bisector method to the wings of Ca II 8542 ${\AA}$ profile, and inspect oscillations of the intensity and the LOS velocity in the pore. In this presentation, we discuss the physical implications of our results in view of a connection between LOS and horizontal plasma flows in a concentrated magnetic flux.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.88.2-88.2
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• 2013

Exploration of the wave-mode identification and its propagating property in the solar pore is desirable to study the energy transfer in the solar atmosphere. The Fast Imaging Solar Spectrograph (FISS) installed at the New Solar Telescope (NST) is a unique system that can do imaging of H-alpha and Ca II 8542 band simultaneously, which is quite suitable for studying of dynamics of chromosphere. In this study, we inspect a relationship between the cross-sectional area and intensity of the pore at continuum (-0.4 nm) near the Ca II line. We find coherent oscillations of the area and intensity. They shows out-of-phase (~ 180 degree difference) in photosphere, which implies that the oscillation is fast sausage mode. We also investigate a relationship between LOS velocities above the pore obtained from the Ca II and the Ha line cores, and find no significant difference of the phase (~10 degree) between the formation heights of the lines in chromosphere.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.4
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• pp.361-369
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• 2008

Control of ground water is one of the most important factors for long-term operation of tunnel because most of tunnel is located in the ground. In case of leakage tunnel, there is no pore water pressure on the lining when the drainage system is properly working. After long-term operation, however, the pore water pressure can be developed on the lining due to the deterioration of the drainage system. The increased pore water pressure on the lining is termed here as 'residual pore water pressure'. Residual pore water pressure can be measured by piezometer, but it is generally not allowed because of damages of drainage system. Therefore, an indirect and nondestructive method is required for evaluating the residual pore water pressure. Moreover, understanding of pore water pressure is needed during healthy operation of the lining. In this study, a new method for evaluation of pore water pressure on the lining during operation is proposed using theoretical and numerical analysis. It is shown that the method is particularly useful for stability investigation of pore water pressure on the lining during operation using theoretical analysis with normalized pore water pressure curve.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.316-325
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• 2009

Adequate conditions of water content and aeration of container media are major environmental factors in the production of pot plant. This experiment was carried out to find optimum physical property of media for the production of small potted Ardisia in capillary mat irrigation system. The plant materials used in this experiment were Ardisia pusilla and Ardisia japonica. Seven substrates were formulated by blending perlite or fresh rice hulls at 20%, 40%, 60% (v/v) with sphagnum peat. Total pore space (TPS) increased by blending sphagnum peat with fresh rice hulls, but decreased by blending sphagnum peat with perlite. As fresh rice hull (FRH) and perlite content increased, air filled pore space (AFP) of substrate increased but container capacity (CC) decreased. Substrate blended with fresh rice hull was higher AFP than blended with perlite and the rate of increase was higher for FRH-containing substrate. As AFP increased, the $CO_2$ concentration in the pot decreased and the $CO_2$ concentration of substrate blended with FRH was higher than blended with perlite. The fresh and dry weight of Ardisia pusilla and A. japonica was the highest in the substrate contained 60% FRH, but the ratio of shoot dry weight to root dry weight was the lowest. The optimum total pore space, air-filled pore space, water holding capacity of substrate for the growth of Ardisia pusilla and A. japonica in the capillary mat irrigation system were 82.8%, 25.6%, and 57.2% respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.1
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• pp.41-50
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• 2004

The numerical investigation for the effects of blasting-induced vibration on adjacent dam and pore water pressure fluctuation was conducted through solid-water coupled analysis under dynamic loading. The stability of dam was examined by peak particle velocity of core. Pore water pressure distributions were calculated by steady state flow analysis using coupled analysis on ground water and blasting-induced vibration. The influence of pore water pressure and the effective stress distribution in the ground were also investigated. Furthermore, effective stress alteration was examined by applying Finn & Byrne Model to monitor the generation and dissipation of pore water pressure.

• Journal of Powder Materials
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• v.18 no.6
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• pp.488-495
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• 2011

This study was performed to fabricate the porous titanium foam by space holder method using NaCl powder, and to evaluate the effect of NaCl volume fractions (33.3~66.6 vol.%) on the porosities, compressive strength, Young's modulus and permeability. For controlling pore size, CP titanium and NaCl particles were sieved to different size range of 70~150 ${\mu}m$ and 300~425 ${\mu}m$ respectively. NaCl of green Ti compact was removed in water followed by sintered at $1200^{\circ}C$ for 2 hours. Total porosities of titanium foam were in the range of 38-70%. Pore shape was a regular hexahedron similar that of NaCl shape. Porous Ti body showed that Young's modulus and compressive strength were in the range of 0.6-6 GPa and 8-127 MPa respectively. It showed that pore size and mechanical properties of Ti foams was controllable by NaCl size and volume fractions.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.1-6
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• 1999

The porosities of PET fibers were investigated using a nitrogen porosimeter according to oxygen plasma treatment and dyeing with a disperse dye, and they were discussed in terms of the change of internal micro-structure of the PET fiber. The total pore volume, surface area and average pore size of the plasma treated PET fibers increased expectably compared with the untreated sample. The PET fibers treated with oxygen plasma and then dyed with a disperse dye were increased significantly in the surface area and the total pore volume comparing with those of plasma treated only, but decreased in the average pore size. The increase of the surface area, after dyeing, of the plasma treated PET fibers was due to addition of the surface area of the dye itself to that of the PET fiber. The increase of the total pore volume of the plasma treated PET fibers by dyeing, which is the opposite result to the general idea that the pore volume of fibers would be reduced by occupation of dye molecules in the pores, could be explained by the free-volume model. This is that the amorphous region in the fiber expanded by occupation of dye molecules, and the marginal space surrounding dyes was generated as many smaller pores, and the decrease of the average pore size of the dyed sample also could be explained The decrease of the average pore size was caused by the splitting of a larger pore into smaller pores.