• 펄프종이기술
• /
• 제37권2호
• /
• pp.47-56
• /
• 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
• /
• 제7권1호
• /
• pp.21-28
• /
• 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.

• 한국통신학회논문지
• /
• 제31권7A호
• /
• pp.674-681
• /
• 2006

본 논문에서는 시스템의 복잡도를 크게 증가시키지 않으면서 다중사용자 간섭과 다중 경로의 영향을 효과적으로 감소시킬 수 있는 DS-UWB 시스템 수신기를 제안하였다. 기존의 비동기식 DS-UWB 시스템 수신기는 확산코드의 종류와 길이에 따라 성능의 편차가 심하다. 일반적으로 확산코드의 길이가 증가하면 수신기의 성능도 따라서 향상되지만, 다중 경로의 영향을 받는 환경에서는 만족할만한 성능 향상을 도모할 수 없다. 제안된 수신기는 다중 사용자 다중 경로 페이딩 환경에서도 다중 경로의 영향을 효과적으로 제거할 수 있음을 여러 가지 컴퓨터 모의실험을 통해서 확인할 수 있었다. 또한 같은 조건에서 기존의 수신기에 비해 사용자수를 크게 증가시킬 수 있음을 확인할 수 있었다.

• Journal of the Korean Wood Science and Technology
• /
• 제40권5호
• /
• pp.311-318
• /
• 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.

• 원예과학기술지
• /
• 제30권5호
• /
• pp.613-616
• /
• 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.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2000년도 추계학술대회
• /
• pp.69-73
• /
• 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.

• 원예과학기술지
• /
• 제32권3호
• /
• pp.415-419
• /
• 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.

• 물과 미래
• /
• 제27권3호
• /
• pp.123-134
• /
• 1994

돌출방류수로에 의하여 동일한 수심의 개수로에 방류되는 부력방류에 의한 연안귀환이 수리실험에 의하여 해석되었다. 부력방류는 온수를 방류하여 발생된다. 돌출방류로 인하여 부력류 하류에 형성되는 재순환영역의 크기는 비돌출방류에서 보다 증가하는 경향을 갖으나 황온도분포는 균일하고 횡단면 최대온도는 감소를 나타낸다. 높은 부력흐름율과는 반대로 낮은 부력흐름율 조건에서 단면평균온도 또는 열흐름율은 돌출길이의 영향이 무시할 정도이다. 비돌출의 경우에는 연안귀환에 유속비가 지배적인 매개변수이었으나 돌출방류의 경우에는 유속비와 후르드수가 다같이 지배적인 인자로 나타났다.

• 한국분무공학회지
• /
• 제27권1호
• /
• pp.1-10
• /
• 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.

• 화훼연구
• /
• 제17권2호
• /
• pp.128-136
• /
• 2009

덩굴 페튜니아의 $F_1$품종 육성을 위한 순계를 선발하기 위하여 품종 및 계통을 수집하여 2004년부터 자가 수분을 매년 1회 또는 2회 실시하여 2008년에는 자식(selfing) 5세대($S_5$) 또는 7세대($S_7$)를 진전시켰으며, 유지하여온 계통 중에서 생육 및 개화 특성이 균일한 surfinia petunia 20개 계통과 wave petunia 28개 계통을 최종적으로 선발하였고 이들의 특성은 다음과 같다. Surfinia petunia는 엽수가 300개 이상이고 초폭이 60 cm 이상으로 생육이 왕성한 계통으로 '$Pe99-017^7$' 등 10개 계통을, 식물체당 개화수가 150개 이상으로 많은 계통으로 '$Pe99-008-1^7$' 등 14개를 선발하였다. 선발된 계통을 화색별로 구분하면 적자색 그룹은 '$Pe99-017^7$' 등 13계통이고, 자주색 그룹은 '$Pe99-007^7$' 등 3계통이고, 남색 그룹은 '$Pe04-086^5$'와 '$Pe04-159^5$' 계통이고, 흰색 그룹은 '$Pe04-072-1^5$'이다. 이들 선발 계통들의 엽장이 3.0~4.0 cm로 작은 계통들은 '$Pe04-086^5$' 등 7개이고, 화경이 4.0~5.0 cm로 작은 계통들은 '$Pe02-205-2^5$' 등 8개이다. 측지수는 6.0개에서 11.0개 정도였으며 절간장은 2.0~4.2 cm로 분포되었다. Wave petunia는 엽수가 200개 이상이고 초폭이 60 cm 이상으로 생육이 왕성한 계통들로는 '$Pe99-020^7$'등 10개 계통이고, 식물체당 개화수가 150개 이상으로 많은 계통들은 '$Pe04-034-2^5$' 등 12개이다. 선발된 계통의 화색에 있어서 적색 그룹은 '$Pe04-113-4^5$'등 3개 계통이고, 적자색 그룹은 '$Pe99-020^7$' 등 18개 계통이고, 자주색 그룹은 '$Pe04-270-2^5$'이고, 청보라색 그룹은 '$Pe04-201^5$'과 '$Pe04-263^5$'계통이며, 보라색 그룹은 '$Pe04-072-5^5$'계통이고, 백색 그룹은 '$Pe04-180-2^5$' 등 3개 계통이다. 엽장이 3.0~4.0 cm로 작은 계통은 '$Pe04-263^5$' 등 11개 이고, 화경이 4.0~5.0 cm로 작은 계통은 '$Pe04-201^5$' 등 9개 이다. 측지수는 8.0개에서 13.0개 정도이고 절간장은 1.0~3.0 cm로 분포되었다. 본 연구로 육성된 덩굴 페튜니아 계통들은 일대잡종 품종육성을 위한 우수한 자원이 될 것으로 본다.