• 대한치주과학회:학술대회논문집
• /
• 2006.11a
• /
• pp.148-148
• /
• 2006

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.532-532
• /
• 2007

UV 경화형 ink를 inkjet printing을 통해 PCB에 patterning 하는 방법에 관한 연구이다. UV 경화형 ink는 일반적으로 ink의 투명도, 색깔, 두께에 따라 완전경화가 밀어나지 않을 수도 있는데 본 연구에서 사용한 UV ink는 particle이 첨가되어 있고 후막 인쇄를 목적으로 하기 때문에 완전경화가 어려웠다. 일반적으로 이러한 UV 경화형 ink의 문제점들을 해결하기 위하여 열경화성 첨가제를 일부 첨가하여 UV에 의한 표면경화와 얼에 의한 속 경화를 진행하는 hybrid system이 사용되고 있지만 본 연구는 PCB를 target으로 하기 때문에 열에 약한 PCB 내의 많은 소자들 때문에 열처리가 쉽지 않은 문제가 있다. 이러한 여러 제약적인 환경에서 UV ink의 완전경화를 위해 경화 process를 최적화 하였으며 10~20um의 후막 인쇄에도 ink가 완전 경화하여 연필경도 9H를 확보하는데 성공하였다.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.915-920
• /
• 2006

Recently available heat pump system by using air heat-source is not efficient. Because the mean temperature of korean winter season is low, economy of air heat-source heat pump descend, and COP is below 3.0. This paper was practiced the simulation on evaluation criteria for heat pump heating and cooling systems to resident building. As a result, heating and cooling composition heat pump system apply to the building needed to be provided heat source for 24 hours.

• BMB Reports
• /
• v.56 no.2
• /
• pp.56-64
• /
• 2023

Nitrogen (N) is an essential macronutrient required for plant growth and crop production. However, N in soil is usually insufficient for plant growth. Thus, chemical N fertilizer has been extensively used to increase crop production. Due to negative effects of N rich fertilizer on the environment, improving N usage has been a major issue in the field of plant science to achieve sustainable production of crops. For that reason, many efforts have been made to elucidate how plants regulate N uptake and utilization according to their surrounding habitat over the last 30 years. Here, we provide recent advances focusing on regulation of N uptake, allocation of N by N transporting system, and signaling pathway controlling N responses in plants.

• The Journal of the Korea Contents Association
• /
• v.17 no.1
• /
• pp.25-38
• /
• 2017

This study investigates non-native speakers(NNS) of English use of backchannels with beginner-intermediate learners' use of 'uh', 'um(uhm)', 'and' and 'hm' suggesting a view as a possible pedagogical implication. The initial aim of this study was to learn this phenomenon and observe their conversation patterns to compare with previous studies. Based on the previous findings, the analyzed data using conventional Conversation Analysis (CA) methods indicate the possible presence of L1 topic markers, '-un' and '-nun' in the form of L2 backchannel tokens when uttered by beginning and intermediate level speakers of English and the presences of L2 backchannel tokens appear only in front of noun phrases. Additionally, these same words with these tokens and when translated back to Korean also require topic markers of '-un' and '-nun.' Finally, This study discusses possible pedagogical implications with the initial analysis of backchannel tokens for Korean EFL learners. In addition, the ultimate goal of this study is to refine this analysis with follow up experiments to validate this investigation into a working hypothesis generating discussions of this backchannel phenomenon from being viewed as a hindrance to as an positive influence that needs to be understood.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.154-154
• /
• 2006

Samsung Electro Mechanics ink jet has developed ultra high resolution alignment system. The alignment system has been developed for repeatable printing of conductive ink. The resolution of alignment system is 0.5um and the velocity of printing working plate is 1.5m/s. So far repeated printing results included sintering process have over 30um of drop mislocation data. In order to improve line thickness and conductivity of metal line, we need to develop the higher mechanical accurate align system. On the demand, this developed align system has under $1{\sim}2{\mu}m$ mispositioning performance and can measure of mechanical accuracy of inkjet printer, as well as the straightness of jetted drop from inkjet head. There is no kinds limit of substrate and ink to use SEM alignment system. By using this alignment system, we progress two experiment of reiterate printing drop and making conductive line on the glass and photo paper. Optical microscope and 3D profiler has been used for measurement of printed ink.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.21 no.4
• /
• pp.206-216
• /
• 1988

In order to set up a predictive model for effective spat collection of pen shell, Atrina (Servatrina) pectinata, the survival rate and time required at each developmental stage of drifting larvae were surveyed during the period from June 8 to October 16 in 1986 at the Yongku inlet Chilchon Is., Chinhae Bay, the southern part of Korea. And also the experiments of spat collection were carried out In Yongku inlet during the period from July 6 to November 23 in 1987 and In Yoja Bay during the period from July 9 in 1987 to February 15 in 1588. The advent of D-shape larvae ca. $135\times144um $ long had three peaks in that area: August 1, 12 and 25. Umbo shape larvae ca. $300\times317um$ and full grown larvae ca. $455\times450um$ long also sowed three peaks: August 9, August 22 and September 4 for the former, and August 23, September 3 and September 16 for the latter. Nine to ten days was required for D-shape larvae to develop to umbo shape larvae. The instantaneous survival rate was 0.94 with a total survival rate if $54\%$ at this intermorphological stage. The required time of umbo to full grown larvae varied from twelve to fourteen days with a instantaneous survival rate of 0.88 and total survival rate of $19\%$. Twenty-two to twenty-three days was required for each group of the D-shape larvae to reach a fullgrown stage, and their total survival rate was $10\%$ during this developmental period. The number of the spat attached to the spat collector is 0.16 inds. per $m^2$ vertical spat collector in Yongku inlet and 0.48 inds. per $m^2$ horizontal spat collector in Yoja Bay. The average shell length of spat attached was $0.51({\pm}0.15)\;mm$ on September $27,\;38.52({\pm}6.98)\;mm$ on November 21 in 1987 and $49.00({\pm}10.77)mm$ on February 15 in 1988.

• Sijohaknonchong
• /
• v.30
• /
• pp.91-107
• /
• 2009

This study is to examine how Sijo is being accommodated to modern Gagok by comparing them. In details, the work is about comparison between three verses in Sijo and twofold grouping in modern Gogok, JoongYuUm in traditional Gagok, YuBak in Sijo, the interlude, ADanSungJang, and changing verses in modern Gagok. First point is about three verses in Sijo and a rhythm of twofold grouping in modern Gagok. In particular, modern Gagok is treated as a group of twofold leaving three verses of Sijo. The way is chosen that whether it sets on an interlude into a song or the third part of three verses in Sijo is extended to avoid its logic of music and poem. Second, the discussion moves points on between an interlude in traditional Gagok and in Sijo. In the process of grouping twofold in modern Gagok, the parts which are interludes of both in traditional Gagok and in Sijo, combined with the interlude of the modern Gagok. It shows that the modern Gagok is affected on both the traditional Gagok and the Sijo. In addition, it explains elements of ADanSungJang - - tones and sounds in the modern Gagok. Originally, the traditional Gagok and sijo are composed of tones and sounds. At this point, tones are short, whereas sounds should be longer. This kind of way in the song has appeared on the modern Gagok of Hong, Nan-Pa. Lastly, the factors is about changing verses of modern Gagok. The one of differences between the modern Sijo and traditional Sijo is verses. For example, when it comes to sijo by Lee, Eun-Sang, he used to create his sijo with three verses. Hence, he did not change verses on his works. Whereas, the modern song "The Spring Lady" by Hong, Nan-Pa has shown the phenomenon that is separating three verses into six verses. It is noticeable that this phenomenon in "The Spring Lady" has the same bases with the modern Sijo.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.7
• /
• pp.547-553
• /
• 2011

We investigated the dielectric and mechanical properties of ceramic polymer composite xBNT - (1-x)LCP (x= 0, 10, 20, 30, 40 vol.%). The disk shaped BNT ($BaNd_2Ti_4O_{12}$) - LCP (liquid crystal polymer) composite samples were prepared by compression molding method. With increasing the BNT content in composites from 10 to 40 vol.%, the dielectric constant increased but the dielectric loss as well as bending strength of composites reduced. These composites were well described with modified Lichtenecker's model having k = 0.392 and 0.303 for the first and second ball milled BNT filled composites, which means that the BNT filler in composites are well dispersed. The dielectric constant of the composite comprised of the second milled BNT ($D_{50}$ = 1.39 um) was higher that of the composite of the first milled BNT ($D_{50}$= 2.45 um), which seems to be related with the different particle size and dispersion of BNT fillers in LCP matrix. The bending strength of the composite containing the second milled BNT was superior to that of the composite of the first milled BNT.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.4
• /
• pp.819-825
• /
• 2016

In this paper, a phase locked loop structure with parallel dual loop which have a different bandwidth has been proposed. The bandwidths depending on transfer functions are obtained through dual loops. Two different bandwidths of each loop are used to suppress noise on the operating frequency range. The proposed phase locked loop has two different voltage controlled oscillator gains to control two different wide and narrow loop filters. Furthermore, it has the locking status indicator to achieve an accurate locking condition. The phase margin of $58.2^{\circ}$ for wide loop and $49.4^{\circ}$ for narrow loop is designed for stable operation and the phase margin of $45^{\circ}$ is maintained during both loops work together. It has been designed with a 1.8V 0.18um complementary metal oxide semiconductor (CMOS) process. The simulation results show that the proposed phase locked loop works stably and generates a target frequency.