• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.357-366
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• 2019

We first confirmed the involvement of MalQ (4-${\alpha}$-glucanotransferase) in Escherichia coli glycogen breakdown by both in vitro and in vivo assays. In vivo tests of the knock-out mutant, ${\Delta}malQ$, showed that glycogen slowly decreased after the stationary phase compared to the wild-type strain, indicating the involvement of MalQ in glycogen degradation. In vitro assays incubated glycogen-mimic substrate, branched cyclodextrin (maltotetraosyl-${\beta}$-CD: G4-${\beta}$-CD) and glycogen phosphorylase (GlgP)-limit dextrin with a set of variable combinations of E. coli enzymes, including GlgX (debranching enzyme), MalP (maltodextrin phosphorylase), GlgP and MalQ. In the absence of GlgP, the reaction of MalP, GlgX and MalQ on substrates produced glucose-1-P (glc-1-P) 3-fold faster than without MalQ. The results revealed that MalQ led to disproportionate G4 released from GlgP-limit dextrin to another acceptor, G4, which is phosphorylated by MalP. In contrast, in the absence of MalP, the reaction of GlgX, GlgP and MalQ resulted in a 1.6-fold increased production of glc-1-P than without MalQ. The result indicated that the G4-branch chains of GlgP-limit dextrin are released by GlgX hydrolysis, and then MalQ transfers the resultant G4 either to another branch chain or another G4 that can immediately be phosphorylated into glc-1-P by GlgP. Thus, we propose a model of two possible MalQ-involved pathways in glycogen degradation. The operon structure of MalP-defecting enterobacteria strongly supports the involvement of MalQ and GlgP as alternative pathways in glycogen degradation.

• 분석과학
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• 제17권4호
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• pp.302-307
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• 2004

환경시료중의 극미량의 악티늄계 동위원소들을 분석하기는 무척 어렵다. 이들 원소들은 개별 분리하는 작업이 필요하며, 알파분광법으로 분석한 어떤 핵종들은 검출감도도 높은 편이다. 이런 극미량의 악티늄계 동위원소들을 분석하기 위해 용매추출법이 결합된 TRU-Spec 이온교환수지와 음이온 교환수지를 사용하여 악티늄계 원소들을 분리한 후 알파분광법으로 검출하였다. 그리고 U과 Th의 검출한계를 낮추기 위해 중성자방사화분석법을 적용하였다. 중성자방사화분석법을 적용하기 위한 바탕물질로 고순도 V foil을 사용하여 검출감도를 10배 향상시킬 수 있었으며, 이 분석법을 표준시료인 NIST-4354, IAEA-368 퇴적물 시료에 적용한 결과 표준값과 10% 이내에서 잘 일치하였다.

• 한국식품영양학회지
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• 제10권3호
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• pp.370-374
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• 1997

시판 식혜에 Saccharomyces cerevisiae를 가해 29$^{\circ}C$에서 10일간 발효시켜서 식혜주를 제조하였다. TLC 및 HPLC 분석 결과 발효에 따라 수크로오스는 2일째부터 글루코오스와 프룩토오스로 가수분해되어 발효되었다. 수크로오스는 6일째에 완전히 없어지고, 8일째에는 글루코오스, 프룩토오스 모두 없어졌다. 에탄올은 6.6%를 나타냈다. 시판 식혜주의 아미노산 함량은 0.32$\mu$mol/ml, 단백질 함량은 226$\mu\textrm{g}$/ml을 나타냈다. pH는 3.21, 산도는 2.5ml를 나타냈다. 한계덱스트린은 1H-NMR로 분석 결과 시판 식혜와 구조상 차이가 없었다. $\alpha$-1,4- 결합에 대한 $\alpha$-1,6- 결합의 비율은 25:1을 나타냈다. 관능검사 결과, 맛은 와인과 비슷하였다.

• 한국게임학회 논문지
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• 제21권3호
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• pp.107-116
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• 2021

바둑에서의 형세 판단은 현재 대국 중인 흑백 대국자 간의 유불리를 판단하는 척도가 되며, 이를 통해 곧바로 적절한 전술과 전략을 구사하게 된다. 본 논문에서는 거리에 따라 반감하는 세력 함수를 활용하여 알파고 간의 50개 대국의 형세 판단을 하고자 했다. 실험 결과에 따르면 단지 세력 함수만을 사용하여 형세 판단을 하게 되면 정확한 판단을 함에 한계가 있음이 밝혀졌다. 이를 극복하기 위해 사석 처리를 위한 사활문제 해결이 필요하며, 이를 보강하게 되면 바둑에서의 정밀한 형세 판단을 할 수 있음을 보였다.

• 천문학회보
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• 제41권2호
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• pp.32.2-32.2
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• 2016

We present the catalog of the KVN Calibrator Survey (KVNCS). This first part of the KVNCS is a single dish radio survey conducted at 22 (K band) and 43 GHz (Q band) simultaneously using the Korean VLBI Network (KVN) from 2009 to 2011. A total 2045 sources selected from the VLBA Calibrator Survey (VCS) with an extrapolated flux limit of 100 mJy at K band. The KVNCS contains 1533 sources in the K band with a flux limit of 70 mJy and 553 sources in the Q band with a flux limit of 120 mJy; it covers the whole sky down to -32. ${\circ}$ 5 in declination. Five hundred thirteen sources were detected in the K and Q bands, simultaneously; ~76% of them are flat-spectrum sources ($-0.5{\leq}{\alpha}{\leq}0.5$). From the flux-flux relationship, we anticipated that the most of the radiation of many of the sources comes from the compact components. Therefore, the sources listed in the KVNCS are strong candidates for high frequency VLBI calibrators.

• 한국군사과학기술학회지
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• 제5권3호
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• pp.89-97
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• 2002

In this study, the effect of $\alpha$-phase morphology on the dynamic deformation behavior at ultra high strain rate was investigated by EBW(Explosive Bridge Wire) test. All of tests and analyses were conducted on three typical microstructures of Ti-6Al-4V alloy, i.e. equiaxed, widmanstatten and bimodal microstructures. The spall strength and HEL(Hugoniot Elastic Limit) of the specimens that have the thickness of 2mm and 4mm were highest with the bimodal microstructure. These results were similar with previous study which was performed by dynamic torsion test(Kolsky torsion test).

• Communications for Statistical Applications and Methods
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• 제3권1호
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• pp.243-255
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• 1996

The number of neutron signals from a neutral particle beam(NPB) at the detector, without any errors, obeys Poisson distribution, Under two assumptions that NPB scattering distribution and aiming errors have a circular Gaussian distribution respectively, an exact probability distribution of signals becomes a Poisson-power function distribution. In this paper, we show that the error rate in simple hypothesis testing for the limiting Poisson-power function distribution is not zero. That is, the limit of ${\alpha}+{\beta}$ is zero when Poisson parameter$\kappa\rightarro\infty$, but this limit is not zero (i.e., $\rho\ell$>0)for the Poisson-power function distribution. We also give optimal decision algorithms for a specified error rate.

• 한국안전학회지
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• 제18권3호
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• pp.46-53
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• 2003

For the tensile tests of the F.E.M., microvoids are created by the boundary separation process at the martensite boundary or neighborhood and at inclusions within the fracture. to grow to the ductile dimple fracture. For the case of the M.E.F., microvoids created at the discontinuities of the martensite phase which exists at the grain boundary of the primary ferrite are grown to coalescence with the cleavage cracks induced at the interior of the ferrite, which as a result show the discontinuous brittle fracture behavior. In spite of their similar tensile strengths, the fatigue limit and the notch sensitivity of the M. E.F. is superior to those of the F.E.M., The M.E.F. is much more insensitive to notch than F.E.M. from the stress concentration factor($\alpha$).

• 한국재료학회지
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• 제2권6호
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• pp.389-397
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• 1992

Li의 양과 Al의 양을 달리한 $\alpha$(HCP) 단상 및 $\alpha$(HCP)+${\beta}$ (BCC) 2상 조직인 Mg-Li-Al합금을 시료로 하여 이 합금의 가공성과 시효경화륵성을 조사한 결과 $\alpha$단상보다는 $\alpha$+${\beta}$ 2상 조이,$\alpha$+${\beta}$ 2상조직에서는 Al양이 많을수록 가궁성이 증가하였으며 Mg-8.08Li-4.26Al의 경우 가공한계값은 62%였다. 이와같이 가공성이 증가한 이유는 basal plane뿐만 아니라 pyramidal plane과 prism plane에서도 슬립이 일어났기 때문이다. $\alpha$단상의 경우 MgL$i_2$ Al(${\theta}$)의 석출이 일어나지 않았으나 $\alpha$+${\beta}$ 2상 조직의 곁우 ${\beta}$상 내에서 ${\theta}$의 석출에 의한 피크경도같이 나타났으며, 2상 조직의 경우 경도값은 Al양이 많을수록 증가하였는데 이것은 Al양의 증가에 따른 Al Partition에 의한$\alpha$ 상의 강화와 ${\beta}$상에서의 석출물 증가에 의한 것으로 생각된다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4215-4220
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• 2011

This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-${\alpha}$, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-${\alpha}$, which were bound to the immunologically captured TNF-${\alpha}$ on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 $ngmL^{-1}$ and showed good linearity up to TNF-${\alpha}$ concentrations as high as 2.0 ${\mu}gmL^{-1}$. The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.