• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.799-801
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• 2005

임베디드 시스템은 소프트웨어와 특수한 기능을 추가한 하드웨어의 긴밀한 결합으로 이루어진다. 이러한 임베디드 시스템 설계는 빠른 시간 안에 안전하면서 다양한 하드웨어와 소프트웨어를 동시에 설계하여 테스트하는 것이 중요하다. 이를 위해서 개발 초기에는 다양한 하드웨어를 설계탈 수 있는 FPGA가 사용된다. 이러한 FPGA를 소프트웨어와 연결시켜주는 하드웨어 콘트롤러와 디바이스 드라이버 설계는 임베디드 시스템 개발에 있어서 중요한 부분을 차지한다. 본 논문은 FPGA를 포함하는 임베디드 시스템의 구조를 모델링하여 하드웨어의 기능에 따라 각 하드웨어를 제어하는 콘트롤러를 자동으로 생성하는 방법을 제안하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.283-284
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• 2016

본 논문에서는 다중 생체계측 장비를 CMCIS(Central Monitoring and Cardiology Information System) 기반의 통합 시스템에 연동하기 위한 내장형 MDEC 모듈을 소개하고 바이탈 사인 장비와 결합하여 무선 네트워킹을 통하여 원격지에 생체정보를 전송하는 시스템을 제안한다. 내장형 MDEC 모듈로 전송된 데이터는 실시간 뷰에 표시됨으로서 환자정보를 원격지에서 감시 및 관리할 수 있는 유효성을 가지게 된다. 본 연구의 결과는 CMCIS 기반의 통합 시스템을 구축하는 기반기술로 향후 효율적 의료서비스에 기여할 것으로 사료된다.

• Journal of the Korean Chemical Society
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• v.45 no.6
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• pp.546-548
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• 2001

Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bond. A combination of silica sulfuric acid and wet SiO$_2$ was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives by using microwave irradiation under solvent free conditions.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.165-171
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• 2017

Diels-Alder 반응은 고리형 탄소화합물을 만드는 유기 합성 과정에서 매우 중요한 반응이다. 이 반응은 중간생성물 없이 오직 1 step으로 진행되는데, diene이나 dienophile에 결합한 치환기의 electron donating 및 electron withdrawing 성질에 따라 반응성이 달라진다고 알려져 있다. 이 때 반응물인 diene과 dienophile의 분자 오비탈 및 전이 상태의 에너지 변화를 계산화학을 통해 분석한다면 Diels-Alder 반응을 보다 심도 있게 이해할 수 있다. 이에 따라 본 연구에서는 DFT 계산을 통하여 치환기에 따른 활성화 에너지의 크기와 diene의 nucleophilicity 및 dienophile의 electrophilicity를 비교하였다. 이를 통해 electron withdrawing group의 경우 분자의 electrophilicity를 증가시키고, electron donating group의 경우 nucleophilicity를 증가시킨다는 것을 확인할 수 있었다. 그 결과, Diels-Alder 반응이 일어날 때 dienophile의 경우 치환된 electron withdrawing group에 의해 electrophilicity가 증가함에 따라 활성화 에너지가 낮아져 반응이 잘 일어나고, 반대로 diene의 경우 electron donating group이 치환되어 있을 때 nucleophilicity의 증가에 따라 반응이 잘 일어난다는 것을 알 수 있었다.

• Information Systems Review
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• v.13 no.3
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• pp.99-121
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• 2011

With the advancement of mobile information technology, the era of smart work emerges as a means for enabling us to overcome temporal and spatial constraints. Thanks to smart mobile devices with seamless access, organizations can assign tasks to employees and provide services to the appropriate customers in mobile environments. In addition, smart work facilitates the improvement of coordination and collaboration among individuals and groups performing organizational tasks. The dramatic performance improvement is manifest by utilization of smart work in organizations. Therefore, the interest in the introduction of smart work is growing. With the lens of time-geography, this study investigates what makes smart work successful. This research, especially, concentrates on the processes for overcoming the temporal and spatial constraints in the field. A case study of the Seoul Metropolitan Rapid Transit Talk and Flash (SMRT T&F) is developed and analyzed through the framework of time-geography and the implementation processes and success factors of SMRT T&F are investigated.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.354-363
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• 2011

Quantum-chemistry study was explored to investigate the electronic structures, absorption and phosphorescence mechanism, as well as electroluminescence (EL) properties of three red-emitting Ir(III) complexes, $(fpmqx)_2Ir$(L) {fpmqx=2-(4-fluorophenyl)-3-methyl-quinoxaline; L=triazolylpyridine (trz) (1); L=picolinate (pic) (2) and L=acetylacetonate (acac) (3)}. The calculated results show that the HOMO distribution for 1 is mainly localized on trz moiety due to its stronger ${\pi}$-electron acceptor ability, and HOMO for 2 and 3 is the combination of Ir d- and phenyl ring ${\pi}$-orbital. The higher phosphorescence yields and differences among 1-3 are investigated in this paper. In addition, the reasons of higher EL efficiency of 2 than 1 and 3 have been rationalized.

• Journal of Food Hygiene and Safety
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• v.13 no.1
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• pp.34-40
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• 1998

Chitin is known as biodegradable natural polymer. But, in spite of various application of chitin from waste marine sources, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. Therefore, we studied that another viscosity chitosan were prepared from chitin which were deacetylated under various concentration of NaOH solution, reaction time and temperature by the application of Mirna's method. The major parameters for these manufacturing methods were found to be concentration of alkali solution, reaction time and temperature etc. Besides, we studied that various chitosan derivatives were prepared from chitin by crosslinkage with epichlorohydrin and 1,3-dichloropropanol. The effects of these parameters on another viscosity(molecular weight) chitosan and crosslinked chitosan dervatives were investigated by various analysis apparatus. SEM analysis showed that both chitin and chitosan had a particle shaped morphology and another molecular weight chitosan according to the particle size was much smaller than that of chitin.

• Membrane Journal
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• v.24 no.4
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• pp.332-339
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• 2014

In this study, an anion-exchange ionomer solution was developed by employing poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) as the base material for the improvement of the capacitive deionization (CDI) performances. It was found that prepared quaternized PPO (QPPO) exhibited excellent ion conductivity superior to that of a commercial anion-exchange membrane (AMX, Astom Corp., Japan) and also the electrochemical properties were shown to be comparable with each other. The CDI tests were conducted by employing the porous carbon electrode coated with the ionomer solution and the result showed the high salt removal efficiency of about 94.9%. By comparing the desalination efficiencies in conventional CDI, membrane CDI (MCDI) with a commercial anion-exchange membrane, and coated CDI (CCDI) employing the porous carbon electrode coated with QPPO, it was confirmed that CCDI shows the high salt removal performance improved by 52.1% and 18.3% compared with those of conventional CDI and MCDI, respectively.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.444-453
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• 2007

Our genome exists in the form of chromatin, and its structural organization should be precisely regulated with an appropriate dynamic nature for life. The basic unit of chromatin is a nucleosome, which consists of a histone octamer. These nucleosomal histones are subject to various covalent modifications, one of which is methylation on certain lysine residues. Recent studies in histone biology identified many histone Iysine methyltransferases (HKMTs) responsible for respective lysine residues and uncovered various kinds of involved chromatin associating proteins and many related epigenetic phenotypes. With the aid of highly precise experimental tools, multi-disciplinary approaches have widened our understanding of how lysine methylation functions in diverse epigenetic processes though detailed mechanisms remain elusive. Still being considered as a relatively more stable mark than other modifications, the recent discovery of lysine demethylases will confer more flexibility on epigenetic memory transmitted through histone lysine methylation. In this review, advances that have been recently observed in epigenetic phenotypes related with histone lysine methylation and the enzymes for depositing and removing the methyl mark are provided.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.242-248
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• 2016

The overall reaction rate of fuel cell is governed by oxygen reduction reaction (ORR) in the cathode due to its slowest reaction compared to the oxidation of hydrogen in the anode. The ORR efficiency can be readily evaluated by examining the adsorption strength of atomic oxygen on the surface of catalysts (i.e., known as a descriptor) and the adsorption energy can be controlled by transforming the surface geometry of catalysts. In the current study, the effect of the surface geometry of catalysts (i.e., strain effect) on the adsorption strength of atomic oxygen on platinum catalysts was analyzed by using density functional theory (DFT). The optimized lattice constant of Pt ($3.977{\AA}$) was increased and decreased by 1% to apply tensile and compressive strain to the Pt surface. Then the oxygen adsorption strengths on the modified Pt surfaces were compared and the electron charge density of the O-adsorbed Pt surfaces was analyzed. As the interatomic distance increased, the oxygen adsorption strength became stronger and the d-band center of the Pt surface atoms was shifted toward the Fermi level, implying that anti-bonding orbitals were shifted to the conduction band from the valence band (i.e., the anti-bonding between O and Pt was less likely formed). Consequently, enhanced ORR efficiency may be expected if the surface Pt-Pt distance can be reduced by approximately 2~4% compared to the pure Pt owing to the moderately controlled oxygen binding strength for improved ORR.