• 제목/요약/키워드: Sigma S

검색결과 1,134건 처리시간 0.038초

루테늄-쿠페론의 전기화학적 행동 및 응용 (Electrochemical behavior and Application of Ruthenium-Cupferron Complex)

  • 권영순;박소영
    • 분석과학
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    • 제17권6호
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    • pp.464-469
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    • 2004
  • 순환 전압전류법을 이용하여, 1 mM 인산염 완충용액에서 루테늄-쿠페론 착물의 전기화학적 행동을 살펴보았다. 루테늄 정량의 최적 조건은 1 mM 인산염 완충용액 (pH 6.0), 0.1 mM 쿠페론의 용액에서 주사속도는 100 mV/s 이었다. 이 조건에서 농도 변화에 따른 선형 주사 전압곡선의 환원 봉우리 전류변화를 이용하여 얻은 루테늄의 검출 한계 ($3{\sigma}$)는 $1.2{\times}10^{-7}M$ 이다.

Average Flow Model을 이용한 Kurtosis의 변화에 따른 Flow Factors에 관한 연구 (Effects of Kurtosis on the Flow Factors using Average Flow Model)

  • 강민호;구영필;조용주
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.280-288
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    • 2000
  • In this study, flow factors are evaluated in terms of kurtosis using random rough surface generated numerically. As h/$\sigma$become large øx, øy, øfp approach to 1 and øs, øfs to 0 asymptotically regardless of kurtosis. øx, øy, øfp increase with increasing kurtosis in the mixed lubrication regime. øs, øfs is associated with an additional flow transport due to the combined effect of sliding and roughness. As h/$\sigma$ decreases øs, øfs increase up to a certain point, and then decrease toward zero. This behavior can be attributed to the increasing number of contacts in the mixed lubrication regime. øx in the presence of elastic deformation on the surface is larger than øx in the absence of it because local film thickness( h$\_$T/) increases by elastic deformation.

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A Study on the Methodology for CTQ Selection in the course of 6-Sigma Activity about Service Company

  • Cho, Jai-Rip
    • 산업경영시스템학회지
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    • 제23권60호
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    • pp.83-89
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    • 2000
  • As customer's needs change rapidly in recent days, the evaluation scale about service quality is changing against the variation of the customer's needs. It is fact that the need of change which established evaluation ways about service quality rise more and more. 6-Sigma activity, called "most innovative management strategy in 20th Century", have many problems apply to service company. The important one between these problems is the problem about Critical To Quality(CTQ) Selection caused from the absence of more precise evaluation system. The objective of this study is the development of methodology for CTQ selection coincide to service company. It is the basic logic that the way to regard MOT mainly effects about total customer satisfaction index(CSI) as CTQ, after the development of the evaluation system based on MOT with customers. Also, the study focused on the case of department store progress to exhibit the reasonableness of this logic.

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On the Measure Extension and Nuclear Space

  • Kim, Myeong Hwan
    • 한국수학교육학회지시리즈A:수학교육
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    • 제22권3호
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    • pp.27-31
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    • 1984
  • In this paper we summarize the characteristic properties of the nuclear space, and then try to establish the relation between Hopf's extension theorem and nuclear space on $\sigma$-Hilbert space.

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Average Flow Model을 이용한 Kurtosis에 따른 Flow Factors에 관한 연구 (Effects of Kurtosis on the Flow Factors Using Average Flow Model)

  • 강민호;김태완;구영필;조용주
    • Tribology and Lubricants
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    • 제17권3호
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    • pp.236-243
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    • 2001
  • In this study, flow factors are evaluated in terms of kurtosis using random rough surface generated numerically. As h/$\sigma$become large ø$\sub$x/, ø$\sub$y/, ø$\sub$fp/, approach to 1 and ø$\sub$s/, ø$\sub$fs/ to 0 asymptotically regardless of kurtosis. ø$\sub$x/, ø$\sub$y/, ø$\sub$fp/ increase with increasing kurtosis in the mixed lubrication regime. ø$\sub$s/, ø$\sub$fs/ is associated with an additional flow transport due to the combined effect of sliding and roughness. As h/$\sigma$ decreases ø$\sub$s/, ø$\sub$fs/ increase up to a certain point, and then decrease toward zero. This behavior can be attributed to the increasing number of contacts in the mixed lubrication regime. ø$\sub$x/ in the presence of elastic deformation on the surface is larger than ø$\sub$x/ in the absence of it because local film thickness(h$\sub$T/) increases by elastic deformation.

삼광(三光) 금(金) 광상(鑛床)의 광화(鑛化) 온도(溫度) 및 근원(根源)에 관關(한) 연구(硏究) (Study on the Temperature and the Origin of Mineralization at the Samkwang Au Deposits)

  • 문건주
    • 자원환경지질
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    • 제19권1호
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    • pp.19-24
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    • 1986
  • The Samkwang mine is one of gold deposits distributed mainly in the southwestern province (Chungnam) of the Korean peninsula. Golds occur in quartz veins aged of $223{\pm}4MA$ according to K-Ar age dating from muscovite in a pegmatitic quartz vein. Quantz veins intrude Precambrian biotite-granite gneiss and mica schist of unknown age. Fluid inclusions in the quartz show a range of homogenization temperatures from 159 to $274^{\circ}C$. A calculated temperature from the isotopes of the galena-sphalerite pair is $375^{\circ}C$. Two phases-fluid inclusions homogenized either by liquid or vapor phase are frequently observed in specimens over $260^{\circ}C$, which may indicate the boiling of the fluids. Pressure of formation of the quartz veins inferred by the homogenization temperatures of liquid-$CO_2$ bearing fluid is 1kb. Based on these data, it is assumed that the temperature of the formation of the Samkwang mine may lie in between $350^{\circ}-230^{\circ}C$. ${\delta}^{34}S_{{\Sigma}s}$ values of sulphide minerals show narrow range of +2.1 to +4.6, and show a trend of enrichments of $^{34}S$ in the fluid from deep to the surface. ${\delta}^{34}S_{{\Sigma}s}$ in the fluid estimated is less than 3 permil, suggesting sulphur fluid originated from the magma.

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SMBH Mass Estimate Discrepancy and Its Origin of NGC 6861

  • 장민성
    • 천문학회보
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    • 제37권2호
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    • pp.69.2-69.2
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    • 2012
  • NGC 6861 is the brightest S0 galaxy in the Telescopium group. It has unusually high central stellar velocity dispersion (~400 km/s) and clear rotation (~250 km/s). Considering the well-known M-sigma relation, this large central dispersion implies that the central supermassive black hole (SMBH) has mass comparable to the most massive black holes in the Universe. However, the mass implied by the bulge luminosity-SMBH mass relation is an order of magnitude lower than that predicted by the M-sigma relation. In order to determine the origin of this inconsistency, we obtain integral field spectroscopy using the Wide Field Spectrograph (WiFeS) on the ANU 2.3m telescope. The data are used to map the velocity and velocity dispersion fields which show that our measurements are consistent with those from the other literature. The large field of view the WiFeS observations have allows us to map the kinematics of a much greater portion of NGC 6861 and reveals that the eastern part of the galaxy has higher velocity and dispersion than the rest of halo. We discuss the origin of the unusual fast rotation and the discrepancy of two SMBH mass estimations from three plausible perspectives: 1) the interaction between subgroups of NGC 6861 and its counterpart, NGC 6868; 2) the inhibited growth of the stellar bulge by the AGN activity which leads to an underestimate the SMBH mass when using the bulge luminosity-SMBH mass relation; and 3) gas rich minor mergers that could be crucial for increasing both rotation velocity and velocity dispersion during the evolution of NGC 6861.

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Dynamic Element Matching을 통한 Multi-bit Delta-Sigma Modulator에서의 DAC Error 감소 방안 비교 (Comparison of Dynamic Elements Matching Method in the Delta-Sigma Modulators)

  • 현덕환
    • 한국정보통신학회논문지
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    • 제10권1호
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    • pp.104-110
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    • 2006
  • 고정도, 저주파용 데이터 변환기로 사용되어온 델타-시그마 변환기는 그 출력 단에 1 bit 혹은 multi-bit 양자화기(ADC)를 사용할 수 있다. 이 중 multi-bit 양자화기를 사용하는 경우 궤환회로에도 multi-bit DAC을 사용하여야 하며 시스템의 데이터 변환 정확도는 DAC의 비선형성에 직접적인 영향을 받는다. 이 영향을 최소화하여 델타-시그마 변환기의 변환 정확도를 높이기 위해서는 DAC에 사용되는 단위 데이터 변환소자 간의 오차가 시스템에 미치는 영향을 최소화 하여야한다. 이 과정 즉 Dynamic Element Matching을 위하여 제안된 4가지 방안(DER, CLA, ILA, DWA)을 비교 설명하였다. 그리고 각 방안을 사용하였을 때 시스템 출력의 잡음 특성을 비교 하였다. 이중 DWA(Data Weighted Averaging) 방안이 가장 우수한 출력 특성을 보였다.