• Industry Promotion Research
• /
• v.2 no.2
• /
• pp.1-6
• /
• 2017

SCADA (Supervisory Control and Data Acquisition) System was first introduced to the Seoul Electricity Authority, which manages the transportation part among the three business fields that produce, transport and supply electric power in Korea. Has been using the data link with 1200 bps and 9600 bps in 5 protocols such as HARRIS 6000, BSC, HDLC, L & N and Toshiba by configuring 3 layers of EMS, SCADA and RTU computer equipments in 1: N radial form. This paper presents the OSI standard network packet flow, analyzing DataLink and Network Layer, and presents a KEPCO SCADA network model composed of X.25 high - speed communication network using 3 layers of network. We proposed a future SCADA communication structure that improved the current SCADA communication structure, defined the SCADA DB structure, introduced the concept of the remote SCADA gateway to the SCADA functional structure, applied the standard communication protocol, Multiplexing of surveillance and control in other local facilities and ensuring communication openness.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.30A no.2
• /
• pp.36-45
• /
• 1993

The n-channel MOSFETs with gate-$n^{-}$S/D overlapped structure have been fabricated by ITLDD(inverse-T gate lightly doped drain) technology. The gate length(L$_{mask}$) was 0.8$\mu$m. The degradation effects of hot carriers injected into the gate oxide were analyzed in terms of threshold voltage, transconductance and drain current variations. The degradation dependences on the gate voltage and drain voltage were characterized. The devices with higher n-concentration showed higher resistivity against the hot carrier injection. As the results of investigating the lifetime of the device, the lifetime showed longer than 10 years at V$_{d}$ = 5V for the overlapped devices with the implantation of an phosphorus dose of 5$\times$10$^{13}$ cm$^{-2}$ and an energy of 80 keV in the n$^{-}$resion.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.377-377
• /
• 2010

FINEMET type nanocrystalline materials synthesized by controlled crystallization of amorphous ribbons[1] exhibit excellent soft magnetic properties making them attractive for technological applications. Present work reports the electronic structure studies of Co-substituted FINEMET to get information on the effect of successive Co substitution on local environment around Fe and Co atom by using near edge x-ray absorption fine structure (NEXAFS) and x-ray magnetic circular dichroism (XMCD) measurements. NEXAFS spectroscopy and XMCD measurements have been carried out at Fe $L_{3,2}$ and Co $L_{3,2}$-edges to investigate the chemical states and electronic structure of FINEMET [$(Fe_{100-x}Co_x)_{78}Si_9Nb_3Cu_1Ba$](0$L_{3,2}$-edge reveal that Fe is in 2+ state and in tetrahedral symmetry with other elements. The magnetic properties exhibiting soft magnetic behavior[2] are discussed on the basis of the electronic structure studied through XMCD.

• Bulletin of the Korean Mathematical Society
• /
• v.42 no.1
• /
• pp.165-167
• /
• 2005

Let M = (R, +, $\cdot$, <, ... ) be an o-minimal expansion of the standard structure R = (R, +, $\cdot$, >) of the field of real numbers. We prove that if 2 $\le$ r < $\infty$, then every n-dimensional definable $C^r$ manifold is definably $C^r$ imbeddable into $R^{2n+l}$. Moreover we prove that if 1 < s < r < $\infty$, then every definable $C^s$ manifold admits a unique definable $C^r$ manifold structure up to definable $C^r$ diffeomorphism.

• BMB Reports
• /
• v.40 no.5
• /
• pp.740-748
• /
• 2007

To gain insight into the structure and function of repressor proteins of bacteriophages of gram-positive bacteria, repressor of temperate Staphylococcus aureus phage ${\phi}11$ was undertaken as a model system here and purified as an N-terminal histidine-tagged variant (His-CI) by affinity chromatography. A ~19 kDa protein copurified with intact His-CI (~ 30 kDa) at low level was resulted most possibly due to partial cleavage at its Ala-Gly site. At ~10 nM and higher concentrations, His-CI forms significant amount of dimers in solution. There are two repressor binding sites in ${\phi}11$ cI-cro intergenic region and binding to two sites occurs possibly by a cooperative manner. Two sites dissected by HincII digestion were designated operators $O_L$ and $O_R$, respectively. Equilibrium binding studies indicate that His-CI binds to $O_R$ with a little more strongly than $O_L$ and binding species is probably dimeric in nature. Interestingly His-CI binding affinity reduces drastically at elevated temperatures ($32-42^{\circ}C$). Both $O_L$ and $O_R$ harbor a nearly identical inverted repeat and studies show that ${\phi}11$ repressor binds to each repeat efficiently. Additional analyses indicate that ${\phi}11$ repressor, like $\lambda$ repressor, harbors an N-terminal domain and a C-terminal domain which are separated by a hinge region. Secondary structure of ${\phi}11$ CI even nearly resembles to that of $\lambda$ phage repressor though they differ at sequence level. The putative N-terminal HTH (helix-turn-helix) motif of ${\phi}11$ repressor belongs to the HTH -XRE-family of proteins and shows significant identity to the HTH motifs of some proteins of evolutionary distant organisms but not to HTH motifs of most S. aureus phage repressors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.542-545
• /
• 2002

High performance organic electroluminescnet(EL) devices which are composed of organic thin multilayer films are fabricated. The basic structure is ITO/Emitting layer/LiF/Al in which have a blended emitting layer. The emitting layer is consisted of a host material(N,N' diphenyl-N,N' (3-methyl phenyl)-l,l'-biphenyl-4,4'diamine)(TPD)) and a guest emitting material(poly(3-hexylthiophehe)(P3HT)). We think that the energy transfer in blending layer occurred from TPD to P3HT. Red emitting multilayer EL devices were fabricated using tris(8-hydroxyqunolinate) aluminum$(Alq_3)$ as electron transport material. The device structure of ITO/blending layer(TPD+P3HT)$/Alq_3$/LiF/Al was employed. In the Voltage-current-luminance characteristics of multilayer device, the device tum on at the 2V and the luminance of $10{\mu}W/cm^2$ obtain at l0V. Red emission peak at 640nm was observed with this device structure. We have presented evidence that the excitation energy migration between a polymeric host and guest has to be explained. And by using multilayer, the red light emitting EL device enhances not only Voltage-current-luminance characteristic but also stability of device.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.9
• /
• pp.1289-1292
• /
• 2006

Potassium(I) with 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate (L) assembles to K($H_2O$)L (L = 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate). It was characterized by single-crystal X-ray diffraction, element analysis, IR and $^1H$ NMR spectroscopy. It crystallizes in the monoclinic space group $P2_1$/n and reveals a seven-coordinate complex. Polyhedra potassium chains, C-H${\cdot}{\cdot}{\cdot}\pi$ and C-H${\cdot}{\cdot}{\cdot}$O and O-H${\cdot}{\cdot}{\cdot}$O hydrogen bonds lead K($H_2O$)L to a three-dimensional network structure. The biological activity of resistance to hypoxia was tested, and the results showed that the biological activity of resistance to hypoxia of K($H_2O$)L is as good as that of its precursor, irisolidone.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.6
• /
• pp.647-650
• /
• 2001

• Korean Journal of Oriental Medicine
• /
• v.12 no.1
• /
• pp.69-75
• /
• 2006

This research was aimed to search for natural antimicrobial agents that are sefe for humans and specific for oral pathogens. Acanthoic was isolated from the chloroform fraction of methanol extract of Acanthopanax koreanum $N_{AKAI}$ and its structure were elucidated by 13-NMR, 1H-NNR and ESIMS. Antibacterial activity of acanthoic acid was investigated by the minimum inhibitory (MIC) and minimun bactericidal (MBC) concentration. MIC/MBC of acanthoic acid against Streptococcus mutans $N_{AKAI}$ causing dental caries was determined to be $2/4\;{\mu}g/mL$, which was much lower than these of other natural antimicrobial agents such as $8/16\;{\mu}g/mL$ of sangurinarine and $250/500\;{\mu}/mL$ of green tea extract, $500/600\;{\mu}g/mL$ of thymol and borneol. Acanthoic and significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus $N_{AKAI}$ and Streptococcus sanguis $N_{AKAI}$, and Streptococcus gordonii $N_{AKAI}$ in the MIC range of $4{\sim}32\;{\mu}g/mL$. My finding suggests that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1690-1691
• /
• 2011

본 논문에서는 H1N1 인플루엔자 A 바이러스(influenza A H1N1 virus) 검출을 위한 산화아연 나노구조(zinc oxide nano structure) 기반의 전기화학적 면역센서를 제작하고 그 특성을 분석하였다. H1N1 인플루엔자 A 바이러스는 빠른 전파 속도 때문에 정확하고 빠른 검출이 필요하다. 먼저, 2 $mm^2$의 표면적을 갖는 패턴된 금 전극 위에 열수방식(hydrothermal method)으로 성장시킨 산화아연 나노구조가 선택적으로 형성되도록 리프트-오프(lift-off) 방법을 사용하였다. 0.01 M phosphate buffered saline(pH 7.4)에서 2 ${\mu}g$/mL 농도의 1차 항체를 정전기력에 의해 산화아연 나노구조에 고정화한 후, 10 pg/mL ~ 5ng/mL 농도의 H1N1 항원을 적용하여 포획 항체에 결합시키고 HRP(horseradish peroxidase) 효소가 결합된 검출 항체를 항원에 결합시키는 샌드위치 ELISA법을 이용하였다. HRP와 반응하는 TMB(3,3', 5,5'-tetramethylbenzidine)와 과산화수소가 포함된 acetate buffered 용액(pH 5)을 전해질로 사용하고 순환전압전류 측정법(cyclic voltammetry)으로 센서의 특성을 분석하였다. 측정된 순환전압전류그래프(cyclic voltammogram)에서 H1N1 항원 농도 10 pg/mL ~ 5 ng/mL의 응답 전류는 276.47 ${\pm}$ 21.72 nA (평균 ${\pm}$ 표준편차, n=4) ~ 478.89 ${\pm}$ 6.21 nA로 측정되었고, logarithmic하게 증가하는 응답 전류 특성을 보였다.