• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.267-273
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• 2005

To develop effective and powerful probiotic, Saccharomyces cerevisiae strains producing cellulolytic enzymes were genetically brooded. For the production of exoglucanase, the plasmid pVT-TExo (8.8 kb) was constructed, in which Thermomonosporafusca exoglucanase gene (E3) was under the control of ADHl promoter, and introduced into S. cerevisiae SEY2102. When the transformant, S. cerevisiae SEY2102/pVT-TExo, was cultivated on YPD medium, the total expression level of avicelase reached about 190 unit/l. The secretion efficiency and plasmid stability were about $50\%\;and\;91\%$, respectively. Recombination exoglucanase enzyme bound to avicel better than Clostridium endoglucanase (CelA) and Trichoderma endoglucanase (C4) enzymes. The mixing ratio of E3 and CelA displaying the best synergistic hydrolysis for avicel was observed at 4:1. The mixture of endoglucanase (CelA) and exoglucanase (E3) resulted in 3.2-fold increase of avicelase activity and 2.5-fold enhanced production of sugar production from avicel, compared to the single enzyme treatment.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.49-57
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• 1994

The binding properties of oxomemazine to muscarinic receptors using the ability of oxomemazine to inhibit $[^3H]QNB$ binding in membrane fractions of rat cerebrum and guinea pig ventricle and ileum were investigated. $[^3H]QNB$ bound to a single class of muscarinic receptors with a dissociation constant of approximately 60 pM in three tissue preparations. Pirenzepine and oxomemazine inhibited $[^3H]QNB$ binding in cerebrum with a Hill coefficient lower than unity, and the inhibition data were best described by a two-site model. The relative densities of the high $(M_1)\;and\;low\;(M_2)$ affinity sites for pirenzepine were 60 and 40%, with corresponding Ki values of 16 and 431 nM, and those $(O_H\;and\;O_L)$ for oxomemazine 40 and 60%, with corresponding Ki values of 80 and 1350 nM. However, the inhibition data of both drugs vs $[^3H]QNB$ in ventricle and ileum appeared to obey the law of mass-action (Hill coefficient close to 1). The apparent Ki values of pirenzepine were 850 and 250 nM, and those of oxomemazine 1460 and 570 nM in ventricle and ileum, respectively. Thus, oxomemazine like pirenzepine has high affinity for cerebrum, moderate affinity for ileum and low affinity for ventricle. These results suggest that oxomemazine could recognize the muscarinic receptor subtypes with a high affinity for the $M_1$ sites.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.751-759
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• 2008

Carrier Ethernet backbone network integrates distributed layer-2 based metro networks. In this networks, Multiple Spanning Tree Protocol (MSTP) has been uscd as a main routing protocol that allows multiple spanning trees in a network. A better routing protocol called IEEE802.1aq - Shortest Path Bridging (SPB) is recently proposed, that generates the shortest spanning tree per a destination node. As SPB provides a routing path per a destination node, there is no way to adapt network traffic at normal condition. If we are free from the principle of "a spanning tree per a destination node", we can achieve adaptive routing. Based on this philosophy, we propose a new spanning tree based protocol - Edge Node Divided Spanning Tree (ENDIST). ENDIST divides an edge node into sub-nodes as many as connecting links from the node and each sub-node generates a single shortest path tree based on SPB. Depending on network or nodal status, ENDIST chooses a better routing path by flow-basis. This added traffic engineering ability contributes to enhanced throughput and reduced delay in backbone networks. The simulation informs us that ENDIST's throughput under heavy load performs about 3.4-5.8 and 1.5-2.0 times compared with STP's and SPB's one respectively. Also, we verified that ENDIST's throughput corresponds to the theoretical upper bound at half of cases we investigated. This means that the proposed ENDIST is a dramatically enhanced and the close-to-perfect spanning tree based routing schemes.

• Journal of the Korea Concrete Institute
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• v.19 no.3
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• pp.359-366
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• 2007

Recently, analysis researches on durability are focused on chloride attack and carbonation due to increased social and engineering significance. Generally, chloride penetration and carbonation occur simultaneously except for in submerged condition and chloride behavior in carbonated concrete is evaluated to be different from that in normal concrete. Furthermore, if unavoidable crack occurs in concrete, it influences not only single attack but also coupled deterioration more severely. This is a study on analysis technique with system dynamics for chloride penetration in concrete structures exposed to coupled chloride attack and carbonation through chloride diffusion, permeation, and carbonation reaction. For the purpose, a modeling for chloride behavior considering diffusion and permeation is performed through previous models for early-aged concrete such as MCHHM (multi component hydration heat model) and MPSFM (micro pore structure formation). Then model for combined deterioration is developed considering changed characteristics such as pore distribution, saturation and dissociation of bound chloride content under carbonation. The developed model is verified through comparison with previous experimental data. Additionally, simulation for combined deterioration in cracked concrete is carried out through utilizing previously developed models for chloride penetration and carbonation in cracked concrete. From the simulated results, CCTZ (chloride-carbonation transition zone) for evaluating combined deterioration is proposed. It is numerically verified that concrete with slag has better resistance to combined deterioration than concrete with OPC in sound and cracked concrete.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.62-71
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• 2013

The passive emitter location method using TDOA and FDOA measurements has higher accuracy comparing to the single TDOA or FDOA based method. Moreover, it is able to estimate the velocity vector of a moving platform. Recently, several non-iterative methods were suggested using the nuisance parameter but the common reference sensor is needed for each pair of sensors. They show also relatively low performance in the case of a long range between the sensor groups and the emitter. To solve this, we derive the estimation method of the position and velocity of a moving platform based on the Gauss-Newton method. In addition, to analyze the estimation performance of the position and velocity, respectively, we decompose the CRLB matrix into each subspace. Simulation results show the estimation performance of the derived method and the CEP planes according to the given geometry of the sensors.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.69-79
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• 2017

The purpose of this study is to reconsider the rating method for the floor impact sound insulation performance in current criterion. Although there are some arguments about proper standard heavy impact source with reproducibility of actual impact source in residence building, bang machine is adopted as the only standard heavy impact source in domestic criterion. To inspect the rating methods of evaluation criteria, this study conducted vibration test for both of standard heavy impact sources and actual impact sources. Using the test results, the floor impact sound insulation performance levels were assessed by each of several criteria. In addition, low frequency noise beyond current criteria was evaluated. Consequently, the floor impact sound levels have different performance levels according to adopted criteria, and measured floor impact sounds are bound to annoy the neighbors in the low frequency range. Current criteria does not consider the spectrum characteristics of floor impact sound according to impact sources and low frequency noise. This may cause the difference between the floor impact sound insulation performance level and human perception. Thus current criterion needs to be complemented to reflect the spectrum characteristics of floor impact sound levels according to impact sources and sound pressure levels in low frequency range.

• Journal of the Korean Regional Science Association
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• v.32 no.2
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• pp.3-13
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• 2016

This study is to analyze the feasibility of a project to digitalize the originals of cadastral maps of North Korea, a total of 299,688 sheets archived in South Korea's National Archives. The cost-benefit analysis is limited on the digitalization of the original cadastral maps of lands, woods and fields, information analysis on land attributes and platform construction, and the benefit analyses are divided into divided territory ones, namely intrinsic value, heritage value, direct and indirect utility value, military and strategic value and the foundation for inter-Korean unification, and post-unification ones such as the confirmation of ownerships, control of social conflicts, reconnection of family lines, arrangement of lot numbers, cadastral management and urban planning. Such benefits are estimated through the double-bound dichotomous choice of the contingent valuation method (CVM). The scenarios show that benefit in the divided territory is expected to reach 586.8billion won in the current value. The amount was calculated from the payable amount (7,925won) multiplied by the whole number of households. The post-unification benefit is estimated at 324.3billion to 594.1billion won as the payable amount (8,023won) is multiplied by the whole number of households.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1760-1768
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• 2020

Vibrio cholerae, cause of the life-threatening diarrheal disease cholera, can be divided into different serogroups based on the structure of its lipopolysaccharide (LPS), which consists of lipid-A, core-polysaccharide and O-antigen polysaccharide (O-PS). The O1 serogroup, the predominant cause of cholera, includes two major serotypes, Inaba and Ogawa. These serotypes are differentiated by the presence of a single 2-O-methyl group in the upstream terminal perosamine of the Ogawa O-PS, which is absent in the Inaba O-PS. To ensure the consistent quality and efficacy of the current cholera vaccines, accurate measurement and characterization of each of these two serotypes is highly important. In this study, we efficiently screened a phage-displayed human synthetic Fab library by bio-panning against Ogawa LPS and finally selected three unique mAbs (D9, E11, and F7) that specifically react with Ogawa LPS. The mAbs bound to Vibrio cholerae vaccine in a dose-dependent fashion. Sequence and structure analyses of antibody paratopes suggest that IgG D9 might have the same fine specificity as that of the murine mAbs, which were shown to bind to the upstream terminal perosamine of Ogawa O-PS, whereas IgGs F7 and E11 showed some different characteristics in the paratopes. To our knowledge, this study is the first to demonstrate the generation of Ogawa-specific mAbs using phage display technology. The mAbs will be useful for identification and quantification of Ogawa LPS in multivalent V. cholerae vaccines.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.121-130
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• 1993

The GaP crystals were grown by synthesis solute diffusion method and its properties were investigated. High quality single crystals were obtained by pull-down the crystal growing ampoule with velocity of 1.75mm/day. Etch pits density along vertical direction of ingot was increased from 3.8 ${\times}{10^4}$c$m^{-2}$ of the first freeze to 2.3 ${\times}{10^5}$c$m^2$ of the last freeze part. The carrier concentration and mobilities at room temperature were measured to 197.49cc$m^2$/V.sec and 6.75 ${\times}{10^{15}}$c$m^{-3]$, respectively. The temperature dependence of optical energy gap was empirically fitted to $E_g$(T)=[2.3383-(6.082${\times}{10^{-4}}$)$T^2$/(373. 096+TJeV. Photoluminescence spectra measured at low temperature were consist with sharp line-spectra near band-gap energy due to bound-exciton and phonon participation in band edge recombination process. Zn-diffusion depth in GaP was increased with square root of diffusion time and temperature dependence of diffusion coefficient was D(Tl = 3.2 ${\times}{10^3}$exp( - 3.486/$k_{\theta}$T)c$m^2$/sec. Electroluminescence spectra of p-n GaP homojunction diode are consisted with emission at 630nm due to recombination of donor in Zn-O complex center with shallow acceptors and near band edge emission at 550nm. Photon emission at current injection level of lower than 100m A was due to the band-filling mechanism.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.748-753
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• 1995

Solid solution of NaNb $O_3$70 mol% and SrTi $O_3$30 mol% was single phase. A broad dielectric peak was found at about l00K. Crystal structure was analysed at room temperature and 12K using Rietveld analysis. The unit cell was assigned to have a a doubled lattice parameter of simple perovskite sturcture at room temperatue, the structure was orthorombic with space group Pmmn. At 12K, the structure was also orthorombic with space group Pnma. This structure change with temperature was due to the distortion of oxygen octahedron. This distortion of oxygen octahedron was made by the decrease of (Ti, Nb)-O bounds length with no variation of (Ti, Nb)-O-(Ti, Nb) bound angle. Therefore the broad dielectirc peak about l00K was attributed to the structural change casued by oxygen octahedron distortion.