• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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• pp.47-56
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• 2005

In technology of ink-jet coating, Image quality from correlation between paper and ink depends on the properties of printer and ink as well as those of paper material. Generally, According to the quality of ink that consists of colorants from 5 to 20 percent, It seems that absorption behavior of each ink is different. In this study, we studied to estimate the effects of dye and pigment ink on the absorption and printing properties using 2-type papers on the market and 3-type silica-based coated papers whose pore structure is different. Using the theory of contact angle to evaluate the absorption property, it was possible to measure the baseline length between paper and ink, volume of droplet as well as contact angle. Also, It was possible to calculate wetting energy(mN/m) and spreading coefficient(mN/m) using the surface tension of each ink. These measurements were available to estimate ink-jet qualities.

• Journal of Communications and Networks
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• v.7 no.1
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• pp.21-28
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• 2005

In this paper, we analyze the performance of code division multiple access (CDMA) systems with orthogonal frequency division multiplexing (OFDM) that employ random spreading sequences in an additive white Gaussian noise (AWGN) channel. We obtain the probability density function (pdf) of the multiple access interference and extend the results to OFDM-CDMA systems to determine the pdf of multiple access and inter-carrier interference in terms of the number of users, the spreading length, the number of sub-carriers, and the frequency offset. We consider the synchronous downlink of cellular multi-carrier CDMA and derive a Gaussian approximation of the multiple access and inter-carrier interference. Overall the effect of frequency offset is shown to vary with the system loading. The analysis in this paper is critical for further development into fading channels and frequency selective multipath channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7A
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• pp.674-681
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• 2006

In this paper, a new receiver with low complexity for a DS-UWB system which can eliminate efficiently the multiple access interference and the detrimental effects caused by multi-paths is proposed. The performance of conventional DS-UWB receivers depends greatly on the types and lengths of spreading codes. Generally, as the length of spreading codes increases, the receiver performance improves. But, the receiver performance does not improve satisfactorily in a multi-paths fading environment. Through computer simulations, it can be shown that the proposed DS-UWB receiver eliminate the multi-paths effects efficiently in a multi-user, multi-paths fading environment, and the user capacity can be increased dramatically using the proposed receiver.

• Journal of the Korean Wood Science and Technology
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• v.40 no.5
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• pp.311-318
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• 2012

This study investigated the flame retardant performance of developed four types of flame retardant chemicals (FRC), FRC-A, B, C and D. Four kinds of soft wood species, Sugi (Cryptomeria), Spruce (Picea abies), Hinoki (Chamaecyparis obtusa) and Korean pine (Pinus koraiensis), were used. The wood specimens were treated by spreading the FRC on the surface with different quantities, 30, 50, 70, 90, 110 g/$m^2$, respectively. The charred area, charred length, after flame time and after glow time were tested. And their suitabilities as incombustible materials were evaluated. The specimen treated by FRC-D showed better incombustible properties than others, even though with lower quantity. Therefore it is supposed that the FRC-D could be able to be applied on the cultural heritage, such as Korean wooden house for preventing fire.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.613-616
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• 2012

The new Cymbidium variety 'Pink Glory' (Palace Court 'Jacky' ${\times}$ Lucky Rainbow 'Saint Rapine') was developed at the National Institute of Horticultural & Herbal Science, Rural Development Administration in 2006. A cross was made in 1995 between C. Palace Court 'Jacky' with a medium sized bright pink colored flowers, and C. Lucky Rainbow 'Saint Rapine' with pink colored flowers. In 1999, one line was selected based on the flower color, leaf shape, flower stalk, and vigorous growth. Evaluation and selection trials were conducted from 2000 to 2004. 'Pink Glory' has a light pink sepal (RHS, RPN66D), red lip (R52B) and a leaf length of 87.5 cm. The average number of flowers on each peduncle was 20.5 and the flower diameter was 8.6 cm. The general impression of petals and sepals showed some incurved and some spreading. 'Pink Glory' has a vigorous growth character and a rounded flower shape. It has an adequate peduncle height (66.5 cm) compared to leaf length (87.5 cm) and starts to bloom in late January under optimal cultural conditions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.69-73
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• 2000

We systematically analyze the influence of fracture junction, solute transfer characteristics on transport patterns in discrete, two-dimensional fracture network models. Regular lattices and random fracture networks with power-law length distributions are considered in conjunction with particle tracking methods. Solute transfer probabilities at fracture junctions are determined from analytical considerations and from simple complete mixing and streamline routing models. For regular fracture networks, mixing conditions at fracture junctions are always dominated by either complete mixing or streamline routing end member cases. Moreover bulk transport properties such as the spreading and the dilution of solute are highly sensitive to the mixing rule. However in power-law length networks there is no significant difference in bulk transport properties, as calculated by assuming either of the two extreme mixing rules. This apparent discrepancy between the effects of mixing properties at fracture junctions in regular and random fracture networks is explained by the statistics of the coordination number and of the flow conditions at fracture intersections. We suggest that the influence of mixing rules on bulk solute transport could be important in systematic orthogonal fracture networks but insignificant in random networks.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.415-419
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• 2014

A Cymbidium variety 'Snow Bell' (C. kanran ${\times}$ C. Jack Frost) was developed at the National Institute of Horticultural & Herbal Science, Rural Development Administration in 2011. A cross between C. kanran with small-sized greenish colored flowers and C. Jack Frost with bright pink colored flowers, was conducted in 1999. Based on flower color, leaf shape, flower stalk, and vigor one line was selected. Evaluation and selection trials were conducted from 2006 to 2010. 'Snow Bell' has a light pink sepal (RHS, R56D), red lip (R56A) and a leaf length of 47.5 cm. The average number of flowers on each peduncle is 13.8 and the flower diameter is 6.2 cm. The characteristics of petals and sepals show some incurve and some spreading. 'Snow Bell' has a vigorous growth and a round flower. It has an adequate peduncle height of 50.7 cm compared with leaf length of 47.5 cm, and start blooming in December. In electronic nose analysis, the degree of fragrance between 'Snow Bell' and the C. kanran was similar and both of them showed strong scents, although they had different fragrance patterns.

• Water for future
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• v.27 no.3
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• pp.123-134
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• 1994

The reattachment of buoyant effluent to shore in a crossflow is investigated experimentally. The effluent is produced by discharging warm water through projecting side channel into a confined cross-flow of the same depth. In the projecting effluent, the size of recirculating region, which is formed by defleted thermal plume on the lee of the effluent, tends to increase, but the maximum temperature decreases in the direction of the crossflow and it has more even transverse spreading compared to non-projecting type. The heat flux across the crossflow is found to be independant of the projected length of the side channel under relatively low buoyancy flux on the contrary to high buoyancy flux. The reattachment of the effluent can be specified by both velocity ratio and densimetric Froude number, whereas only the velocity ratio is governing factor to the reattachment of the effluent in the case of non-projecting type.

• Journal of ILASS-Korea
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• v.27 no.1
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• pp.1-10
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• 2022

In this study, an experimental investigation on the effects of the pressure ratio on the wall-impingement spray characteristics of nitrogen gas using a compressed natural gas (CNG) injector was conducted. The transient development of the impingement spray was recorded by a high speed camera with Z-type Schlieren visualization method. The spray behavior under various pressure ratio conditions were analyzed. The experimental results showed that the pressure ratio has positive effect on the development of spray wall-impingement. The effects of the above factor were evaluated in a constant volume chamber at atmospheric conditions. The data from test showed that, with the increase of the pressure ratio, the spray tip penetration (STP) quickly increases before the impingement and gradually increases after the impingement. Additionally, the spray velocity first increases and then sharply decreases on regardless of the injection pressure level. As the spray spreading angle increases, spray area and volume increases rapidly with the increase in STP at the beginning of injection, and finally entered a stable range, has a great correlation with the increase of pressure ratios.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.128-136
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• 2009

To obtain pure lines for breeding $F_1$ varieties of spreading surfinia and wave petunia, Petunia ${\times}$ hybrida, 20 lines of surfinia petunia and 28 lines of wave petunia that were considered uniform in growth and flowering characteristics were selected by self-pollination of the fifth($S_5$) or the seventh generation($S_7$). The 20 selected lines of surfinia petunia had the branch number ranged from 6.0 to 11.0 cm, and the internode length ranged from 2.0 to 4.2 cm. Among them, ten lines, including '$Pe99-017^7$' were above 60 cm of plant width, above 300 leaves in a plant. Fourteen lines including '$Pe99-017^7$' were more than 150 in the number of flower. In the petal color, thirteen lines, including '$Pe99-017^7$', were red-purple; three, including '$Pe99-007^7$', were purple; '$Pe04-086^7$' and '$Pe04-159^7$' were violet; and line '$Pe072-1^7$' was white. Eight lines including '$Pe02-205-2^5$' ranged from 4.0 to 5.0 cm of flowers diameter, and seven lines including '$Pe04-086^5$' ranged from 3.0 to 4.0 cm of leaf length, which is relatively low. Germination rate of the lines was more than 50%. In the wave petunia, the branch number of the 28 selected lines ranged from 8.0 to 13.0 cm, and the internode length ranged from 1.0 to 3.2 cm, which is relatively higher than surfinia petunias. Among them, ten lines, including '$Pe99-020^7$' were above 60 cm of plant width, above 200 leaves in a plant. Twelve lines including '$Pe04-034-2^5$' were more than 150 in the number of flower. In the petal color, eighteen lines, including '$Pe99-020^7$', were red-purple; three, including '$Pe04-113-4^5$', were red; three, including '$Pe04-263^5$', were white; '$Pe04-201^5$' and '$Pe04-263^5$' were violet blue; and line '$Pe04-072-5^5$' was purple. Nine lines including '$Pe04-201^5$' ranged from 4.0 to 5.0 cm of flowers diameter, and eleven lines including '$Pe04-263^5$' ranged from 3.0 to 4.0 cm of leaf length, which is relatively low. All the lines with various growth and flowering characteristics would be very promising to use as breeding materials for $F_1$ hybrids of spreading petunia, Petunia ${\times}$ hybrida.