• Spatial Information Research
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• v.11 no.3
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• pp.251-260
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• 2003

Distribution pattern of seawater intrusion was analyzed from the spatial distribution map of chloride using the geostatistics and CIS analyses. The chloride distribution map made by kriging(ordinary kriging and co-kriging) after exploratory spatial data analysis. Kriging provides an advanced methodology which facilitates quantification of spatial features and enables spatial interpolation. TDS, Na$^{＋}$, Br$^{[-10]}$ were selected as second parameters of co-kriging which is higher value of correlation coefficients between chloride and others groundwater properties. Chloride concentration is highest in yeminchon and coastal area. And result in co-kriging was accurate than ordinary kriging.

• Analytical Science and Technology
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• v.7 no.2
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• pp.187-191
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• 1994

A reactive intermediate 1,2-dihydropyridine derivative 2 has been prepared and isolated from the reaction of pyridine with $^tBuLi$ and trimethylchlorosilane in nonpolar condition at low temperature 2 has characterized by $^1H-NMR$ fine structure analysis with SPINX3. The mechanistic information of formation of 2 was obtained from synthesized 2,5-disubstituted pyridine derivatives 3 and 4.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.13-19
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• 2008

In this paper, we propose a new CL-OSTBC (Closed Loop Orthogonal Space-Time Block Code) scheme for four transmit antennas and compare the scheme with existing closed loop schemes on the performance of BER (Bit Error Rate). In the proposed scheme, a transmitter receives channel feedback information and combines modulated symbols by the symbol combiner, and transmits the symbols encoded by the space-time block encoder. As a result, the proposed scheme achieves full-rate and maximal channel gains by more efficient utilization of the channel feedback information. Moreover, the scheme can reduce computation complexity by using a linear detector. Simulation results on the BER performance show that the proposed CL-OSTBC scheme outperforms existing CL-OSTBC schemes.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.679-683
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• 2005

In this study, we investigate the characteristic of the poly-Si grain and morphology influenced by XeCl excimer laser system. The stable laser beam source is basic requested; the irradiation beam through optical lens module is more important which limit the grain size smaller than $0.5{\mu}m$. The homogenization lens designs control the poly-Si grain size; so we hardly get enlarge grain size by one laser irradiation scan.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.857-859
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• 2007

Durability of LCD glass, OA-10 and OA-21, to $SiCl_4$ and $SF_6$ gases was investigated. Reaction products are generated on the glass surface. The reaction products are reduced by changing the etching conditions. the durability of OA-10 and OA-21 to the dry etching gases is comparable.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.77-79
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• 2004

Optimization of the biphenile chloromethylation process with paraphormaldegide has been done in the presence of ZnCl$_2$ with HCI gas by the Box-Wilson method of mathematical planning of experiment. The 4, 4'-( dichloromethyl)-biphenile yield dependence on the biphenile - paraphormaldegide ratio, temperature and reaction duration has been studied. A mathematical model of the process has been developed and optimal conditions for the biphenile chloromethylation procedure has been determined

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.80-84
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• 2005

Many important properties in colloidal systems are usually determined by surface charge ($\zeta$-potential) of the contacted solid surface. In this study, $\zeta$-potential of glass $\mu$-channel was evaluated from the electro-osmotic velocity distribution. The electro-osmotic velocity inside a glass $\mu$-channel was measured using a micro-PIV velocity field measurement technique. This evaluation method is more simple and easy to approach, compared with the traditional streaming potential technique. The $\zeta$-potential in the glass $\mu$-channel was measured for two different mole NaCl solutions. The effect of an anion surfactant, sodium dodecyl sulphate (SDS), on the electro-osmotic velocity and $\zeta$-potential in the glass surface was also studied. In the range of $0\∼6$mM, the surfactant SDS was added to NaCl solution in four different mole concentrations. As a result, the addition of SDS increases $\zeta$-potential in the surface of the glass $\mu$-channel. The measured $\zeta$-potential was found to vary from-260 to-70mV. When negatively charged particles were used, the flow direction was opposite compared with that of neutral particles. The $\zeta$-potential has a positive sign for the negative particles.

• Journal of the Korea Society of Computer and Information
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• v.11 no.2 s.40
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• pp.201-211
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• 2006

The standardization of third Generation Partnership Project(3GPP) has been performed in of order to support interactive multimedia services under mobile environments. In this 3GPP, transmit diversity solutions are applied to increase the available diversity effectively using 2 or more antennas. In this paper, we analyzer the performances on STTD(Space Time Transmit Diversity) technique and its modified techniques such as STTD-OTD, CL-STTD, and 4TX-STTD out of open loop transmit diversities that the standardization of 3GPP has released. We also propose the open loop transmitter and receiver diversities to add the receiver diversity. We analyze and discuss the performance of the proposed techniques and using the Matlab simulation under the flat fading channel environment.

• Journal of The Korean Association of Information Education
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• v.16 no.3
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• pp.319-326
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• 2012

In this paper, we studied a design-based learning for Computational Thinking in Computational Literacy. The design-based learning for computational thinking in computational literacy education started from a MIT media laboratory in 2011. We revised the design-based learning and applied it to educational field. We considered educational strategies and derived the implications, after teaching fourth grade gifted students. Moreover we conducted and analyzed a questionnaire survey, observations and interviews. As the result, the design-based learning in computational literacy is effective for creative computational thinking that students create their ideas and make a meaningful artifacts from it. We expect that this study provides the basic data to apply a design-based learning for computational thinking to Computer education.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.582-588
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• 1999

정보화 사회의 발전과 함께 멀티미디어에 대한 관심이 집중되고 있으며, 점유 공간이 작고 가벼우며 대면적이 가능한 정보 표시 디스플레이에 대한 기술은 고부가가치 산업으로 인식되어 지고 있다. 이러한 정보 표시 디스플레이들 중, 전기 발광 소자 (Electroluminescence Display : ELD), 액정 표시 디스플레이 (Liquid Crystal Display LCD), 플라즈마 디스플레이 (Plasma Display Panel) 등의 대한 연구가 세계적으로 매우 활발하게 진행되고 있다. 본 연구에서는 란탄 계열의 금속 착 화합물인 Tb(ACAC)$_3$(Phen)과 Tb(ACAC)$_3$(Phen-Cl)를 이용해 다비이스를 제작한후 광학적 및 전기적 특성을 조사하였다. 또한 luminous efficiency와 cyclic voltametric 방법을 이용해 에너지 밴드로 두 발광 물질인 Tb(ACAC)$_3$(Phen)과 Tb(ACAC)$_3$(Phen-Cl)을 비교.분석하였다. 본 연구의 디바이스 구조를 보면 anode/hole transporting layer (HTL)/emitting material layer (EML)/electron transporting layer (ETL)/cathode와 같고 ETL를 aluminum-tris- (8-hydroxyquinoline) (Alq$_3$)와 bis(10-hydroxybenzo(h)quinolinato)beryllium (Bebq$_2$)를 사용하였으며 HTL 로 N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD)를 사용하였다.