• Title/Summary/Keyword: Sigma S

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The Regulation of Alpha-Amylase Synthesis in Bacillus subtilis

  • Won, Mi-Sun
    • Journal of Microbiology and Biotechnology
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    • v.1 no.4
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    • pp.256-260
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    • 1991
  • In B. subtilis, $\alpha$-amylase synthesis is regulated by amyR located directly on the upstream of amyE. Three different amyR alleles have been reported, amyR1, amyR2 and amyR3. Strains bearing the gra-10 mutation which confers derepression for catabolite repression has GlongrightarrowA transition mutation at +5 of amyR1. S1 nuclease mapping demonstrated that transcription initiated at 8 bases downstream from the -10 region of putative E$\sigma^{A}$ promoter P1 in amyR1 and gra-10. In amyR2, the major transcription initiatd at the same place and the minor, 10 bases downstream from -10 of P2. The transcript from P2 contributed approximately 15-20% of total amyE mRNA. S1 nuclease protection experiment indicated that amyE mRNA levels corresponded to the rate of synthesis assumed by specific activities of $\alpha$-amylase in culture supernatants, suggesting that $\alpha$-amylase synthesis is regulated at the level of transcription.n.

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A NOTE ON INVARIANT PSEUDOHOLOMORPHIC CURVES

  • Cho, Yong-Seung;Joe, Do-Sang
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.2
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    • pp.347-355
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    • 2001
  • Let ($X, \omega$) be a closed symplectic 4-manifold. Let a finite cyclic group G act semifreely, holomorphically on X as isometries with fixed point set $\Sigma$(may be empty) which is a 2-dimension submanifold. Then there is a smooth structure on the quotient X'=X/G such that the projection $\pi$:X$\rightarrow$X' is a Lipschitz map. Let L$\rightarrow$X be the Spin$^c$ -structure on X pulled back from a Spin$^c$-structure L'$\rightarrow$X' and b_2^$+(X')>1. If the Seiberg-Witten invariant SW(L')$\neq$0 of L' is non-zero and $L=E\bigotimesK^-1\bigotimesE$ then there is a G-invariant pseudo-holomorphic curve u:$C\rightarrowX$,/TEX> such that the image u(C) represents the fundamental class of the Poincare dual $c_1$(E). This is an equivariant version of the Taubes' Theorem.

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AC Conductivity and Dielectric Constant of Ni-MgO Composites (Ni-MgO 복합재료의 전기전도도와 유전상수)

  • ;Eric R. Kreidler
    • Journal of the Korean Ceramic Society
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    • v.28 no.4
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    • pp.329-337
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    • 1991
  • The Ni-MgO composites were prepared by coprecipitation of NiO-MgO solid solutions and their selective reduction in a hydrogen atmosphere. We report on the measurements of both ac conductivity $\sigma$ ($\omega$, f) and dielectric constant $textsc{k}$'($\omega$, f) for the Ni-MgO composites in the frequency range from 10 Hz to 10 MHz at room temperature. The frequency exponents of conductivity and dielectric constant, x and y, are found to be x=0.98$\pm$0.05 and y=0.05$\pm$0.01. These results are in good agreement with a general scaling relation $\chi$-y=1, although these values are different from the theoretical predications. The dielectric constant exponent ($textsc{k}$' f-fc -s) is found to be s=0.62$\pm$0.07 with estimated percolation threshold fc=0.20$\pm$0.02.

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3 Months Repeated Dose Toxicity Studies of the Bamboo Salt(Jukyum) in Rats (죽염에 대한 3개월 반복투여 독성시험연구)

  • 김준규;서경원;이봉훈;박미경;박창원;신동환;홍충만;한범석;김윤정
    • Toxicological Research
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    • v.18 no.2
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    • pp.149-157
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    • 2002
  • Though the bamboo salt, called as "JUKYUM" has been widely used in Korea as panacea, it's toxicity was not screened completely. To investigate the toxicity of bamboo salt, we compared with the toxicity of crude salt and reagent-grade NaCl by performing repeated dose (3 month's) oral toxicity test in SD rats. Crude salt, natural sun-dried salt (crude salt) production, was purchased from the western seashore of Korean peninsular and reagent-grade NaCl was purchased from Sigma company. Results of repeated dose oral toxicity tests for 3 months (bamboo salt; 750, 1500, 3000 mg/kg/day, crude salt : 3000 mg/kg/day, reagent-grade NaCl; 3000 mg/kg/day) suggested that the bamboo salt treated group show no significant toxicological findings with body weights and organ weighs changes, and hematological, serum bio-chemical and histopathological findings compared with other groups.er groups.

A case study on innovation in urban railway depot (도시철도 차량기지 혁신사례 분석)

  • Chung, Su-Young;Park, Soo-Choong;Lee, Seong-Gwon;Lee, Seung-Hwan
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.104-109
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    • 2010
  • Management innovation as a strategic alternative to create competitive advantages in the global market, is being actively progressed by conglomerates such as Samsung, LG and Toyoda as they cut a brilliant figure in the 21 century by using various innovation methods. However, the domestic railway sectors, in particular urban railway depots have neglected management innovation as they undertake Operation and Management in non-competitive settings of a corporate enterprise. This paper analyzes the critical success factors that have switched the most obsolete depots to a benchmark model for domestic railway depots based on the remodeling businesses undertaken in Gunja rolling stock maintenance office, Korea's first urban railway depot, along with 5S 6sigma program.

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The Effects of Taglisodog-eum Extract on Antioxidant and Antiinflammatory ability in mouse cell (Mouse cell에서 탁리소독음(托裏消毒飮)의 항산화작용과 항염증 효과)

  • Lee, Sang-Moon;Hong, Seung-ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.3
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    • pp.43-50
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    • 2007
  • Background and Objectives : The aim of this study was to investigate the anti-oxidant and anti-inflammatory effects of the Taglisodog-eum(TSE) extract on the RAW264.7 cell Methods : The RAW264.7 cell was cultured using Dulbecco's modified Eagle's medium(DMEM, USA), including the 10% fetal-bovine serum(FBS; Sigma, USA) in a $37^{\circ}C$, 5% CO2 incubator. Results : The anti-oxidant ability of TSE were dose-dependantly increased. The LPS-induced IKK, iNOS and COX-2 mRNA expression were dose-dependantly decreased in the RAW264.7 cells treated with TSE. $NF-kB$ activation was suppressed. Conclusion : The findings in this study show that TSE has anti-oxidant and anti-inflammatory effects, such as the inhibition of $NF-kB$ activity.

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Development of Thermoplastic-Thermoset Multi Component Injection Mold for a Waterproof Connector (방수커넥터용 열가소성-열경화성 이종소재 사출금형 개발)

  • Jung, T. S.;Choi, K. S.
    • Transactions of Materials Processing
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    • v.24 no.6
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    • pp.418-425
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    • 2015
  • Based on eco-friendly advantages and the enhanced development in the chemical and physical characteristics, liquid silicone rubber (LSR) is widely used in producing precision parts in the automotive, medical, electronics, aeronautical and many other industries. In the current work, a thermoplastic-thermoset multi component injection molding (MCM) was developed for a waterproof automotive connector housing using PBT and LSR resins. Measurements of the rheological characteristics of PBT and LSR were made to improve the reliability of the numerical analysis for the multi component injection process. With the measured viscosity, pvT and curing data, numerical analysis of the multi cycle injection molding was conducted using simulation software (Sigma V5.0).

The Effect of Additive on the Electric conductivity of Insulating Oil (절연유의 전기전도에 미치는 첨가제의 영향(II))

  • Chung, K.H.;Kim, Y.B.;Kim, Y.I.;Park, S.H.;Park, J.Y.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1630-1632
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    • 1996
  • The static charges are generated by streaming electrification phenomena when insulating oil flowing by force for the purpose of cooling at the internal of Ultra-high power transformer. In this thesis, their elimination method was studied. In this paper the effect of Additive on the electric conductivity of Insulating oil is studied. The variation of electric conductivity disappear when Additive is molten in insulating oil, the variation of Additive is not enough to decrease streaming electrification of insulating oil(${\sigma}>10^{-12}$[S/cm]).

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A Study on a Design of Efficient Electronic Commerce System

  • Ko Il-Seok;Shin Seung-Soo;Choi Seung-Kwon;Cho Yong-Hwan
    • Proceedings of the Korea Contents Association Conference
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    • 2004.05a
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    • pp.234-240
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    • 2004
  • Now that the e-commerce users are explosively increasing, there is always followed by a sharp increase in load from the e-commerce system and the heavy traffic on the network, where leads to the delayed service for the client's request. The natural consequences contain decreasing customer satisfaction and weakening the business's competitive position in markets. Therefore, we'll need to study the e-commerce system in due consideration of the operational efficiency and response speed. This study includes a design of e-commerce system, with a hierarchical structure based on the local server, which has the capability of caching necessary to distribute the system load, makes a proposal concerning a split web-cache algorithm devoted to the local web server to finally give an analysis of the performance through the appropriate trial.

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The Effect of Additive on the Electric conductivity of Insulating Oil (절연유의 전기전도에 미치는 첨가제의 영향)

  • 정광현;김영봉;김용운;임헌찬;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.05a
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    • pp.158-161
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    • 1996
  • The static charges are generated by streaming electrification phenomena in insulating oil flowing by force for the purpose of cooling at the internal of Ultra-high power transformer. In this thesis, their elimination method was studied. In this paper the effect of Additive on the electric conductivity of Insulating oil is studied. The variation of electric conductivity disappear when Additive is molten in insulating oil BTA(Benzotriazole) appear more variation of electric conductivity than that of SP-S10(Sorbitan mono-stearate). But the variation is not enough to decrease streaming electrification of insulating oil($\sigma$>10$\^$-12/[S/cm]).

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