• Title/Summary/Keyword: sigma ($\sigma$) phase

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A Case Study of Six Sigma Project for Improving Customer Satisfaction of a Franchise store (6시그마를 활용한 프랜차이즈업의 고객만족도 향상에 관한 연구)

  • Kim, Dong-Kyu;Han, Won-Hyung;Kim, Jin-A;Sung, Yu-La;Lee, O-Mi;Cho, Yong-Wook
    • Journal of the Korea Safety Management & Science
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    • v.12 no.1
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    • pp.161-168
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    • 2010
  • This paper presents a six sigma project for improving customer satisfaction of a franchise store. The project follows a disciplined process of five macro phase : define, measure, analyze, improve, and control(DMAIC). Due to the limitation of existing methodologies, numerous difficulties arise during the six sigma application to transactional processes. This paper expected to be helpful to service industry in which is very difficult to measure and implement.

Fractional-N Frequency Synthesis: Overview and Practical Aspects with FIR-Embedded Design

  • Rhee, Woogeun;Xu, Ni;Zhou, Bo;Wang, Zhihua
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.2
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    • pp.170-183
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    • 2013
  • This paper gives an overview of fractional-N phase-locked loops (PLLs) with practical design perspectives focusing on a ${\Delta}{\Sigma}$ modulation technique and a finite-impulse response (FIR) filtering method. Spur generation and nonlinearity issues in the ${\Delta}{\Sigma}$ fractional-N PLLs are discussed with simulation and hardware results. High-order ${\Delta}{\Sigma}$ modulation with FIR-embedded filtering is considered for low noise frequency generation. Also, various architectures of finite-modulo fractional-N PLLs are reviewed for alternative low cost design, and the FIR filtering technique is shown to be useful for spur reduction in the finite-modulo fractional-N PLL design.

A Study on Design for Six Sigma Methodology for Aircraft Industry (항공 산업의 DFSS 적용방법에 관한 연구)

  • Sung, Su-Gyeong;Yoon, Hee-Kweon;Kwag, Sang-Hyug;Byun, Jai-Hyun
    • Journal of Korean Society for Quality Management
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    • v.40 no.3
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    • pp.316-326
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    • 2012
  • Purpose: In this paper, a Design for Six Sigma(DFSS) methodology based on DMADV(Define-Measure-Analyze-Design-Verify) roadmap is presented. Methods: DFSS tools are given for each DMADV phase which is suitable for the aircraft development process. A cost reduction case study of a navigation simulation is demonstrated. Results: DFSS roadmap are presented with implementation tools for each phase. Conclusion: We propose a DFSS methodology which can benefit the design and development personnel to implement DFSS not only in aircraft industry but also in other order-based industries in general.

A Semi-empirical Model for Polarimetric Radar Backscattering from Bare Soil Surfaces

  • Oh, Yi-Sok
    • Korean Journal of Remote Sensing
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    • v.17 no.2
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    • pp.141-153
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    • 2001
  • A semi-empirical polarimetric backscattering model for bare soil surfaces is presented. Based on measurements by using polarimetric scatterometers and the JPL AirSAR, as well as the theoretical models, the backscattering coefficints $\sigma$$^0_w$, $\sigma$$^0_{hh}$ and $\sigma$$^0_{vh}$, and the parameters of the copolarized phase-difference probability density function, namely the degree of correlation $\alpha$ and the copolarized-phase-difference $\zeta$, are modeled empirically in terms of the volumetric soil moisture content m$_v$ and the surface roughness parameters $k_s$ and $k_l$, where k=2$\pi$f/c, s is the rms height and l is the correlation length.

Relations between Resonance Structures in Photoionization Spectra in Three-Channel-Systems Studied by Multichannel Quantum Defect Theory

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.33 no.7
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    • pp.2168-2176
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    • 2012
  • Relations between fitted parameters for photoionization spectra both below and above the thresholds in the systems involving 3 channels are obtained using phase-shifted version of the multichannel quantum-defect theory. Analytical continuation of the photoionization cross sections in the form of ${\langle}{\sigma}_{below}{\rangle}_{v_{below}}={\sigma}_{above}$ examined using several representations.

A Two-Point Modulation Spread-Spectrum Clock Generator With FIR-Embedded Binary Phase Detection and 1-Bit High-Order ΔΣ Modulation

  • Xu, Ni;Shen, Yiyu;Lv, Sitao;Liu, Han;Rhee, Woogeun;Wang, Zhihua
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.4
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    • pp.425-435
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    • 2016
  • This paper describes a spread-spectrum clock generation method by utilizing a ${\Delta}{\Sigma}$ digital PLL (DPLL) which is solely based on binary phase detection and does not require a linear time-to-digital converter (TDC) or other linear digital-to-time converter (DTC) circuitry. A 1-bit high-order ${\Delta}{\Sigma}$ modulator and a hybrid finite-impulse response (FIR) filter are employed to mitigate the phase-folding problem caused by the nonlinearity of the bang-bang phase detector (BBPD). The ${\Delta}{\Sigma}$ DPLL employs a two-point modulation technique to further enhance linearity at the turning point of a triangular modulation profile. We also show that the two-point modulation is useful for the BBPLL to improve the spread-spectrum performance by suppressing the frequency deviation at the input of the BBPD, thus reducing the peak phase deviation. Based on the proposed architecture, a 3.2 GHz spread-spectrum clock generator (SSCG) is implemented in 65 nm CMOS. Experimental results show that the proposed SSCG achieves peak power reductions of 18.5 dB and 11 dB with 10 kHz and 100 kHz resolution bandwidths respectively, consuming 6.34 mW from a 1 V supply.

Partial Purification of Factors for Differential Transcription of the rrnD Promoters for Ribosomal RNA Synthesis in Streptomyces coelicolor

  • Hahn, Mi-Young;Roe, Jung-Hye
    • Journal of Microbiology
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    • v.45 no.6
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    • pp.534-540
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    • 2007
  • The Streptomyces coelicolor A3(2) genome contains six operons (rrnA to F) for ribosomal RNA synthesis. Transcription from rrnD occurs from four promoters (p1 to p4). We found that transcripts from the p1 and p3 promoters were most abundant in vivo in the early exponential phase. However, at later phases of exponential and stationary growth, transcripts from the p1 promoter decreased drastically, with the p3 and p4 transcripts constituting the major forms. Partially purified RNA polymerase supported transcription from the p3 and p4 promoters, whereas pure reconstituted RNA polymerase with core enzyme (E) and the major vegetative sigma factor ${\sigma}^{HrdB}$ ($E{\cdot}{\sigma}^{HrdB}$) did not. In order to assess any potential requirement for additional factor(s) that allow transcription from the p3 and p4 promoters, we fractionated a partially purified RNA polymerase preparation by denaturing gel filtration chromatography. We found that transcription from the p3 and p4 promoters required factor(s) of about 30-35 kDa in addition to RNAP holoenzyme ($E{\cdot}{\sigma}^{HrdB}$). Therefore, transcription from the p3 and p4 promoters, which contain a consensus -10 region but no -35 for ${\sigma}^{HrdB}$ recognition, are likely to be regulated by transcription factor(s) that modulate RNA polymerase holoenzyme activity in S. coelicolor.

Process Model for 6 Sigma(${\sigma}$) in Construction Management(CM) (건설사업관리(CM)에서의 6시그마(${\sigma}$) 적용 조건 분석을 통한 추진 모델 구축)

  • Kim, Chan-Gyo;Lee, Jea-Sauk;Chun, Jae-Youl
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2006.11a
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    • pp.478-482
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    • 2006
  • The domestic enterprises in order to secure the freshness location of market from the international competition which is keen are propelling a price and a quality high position strategy steadily. It is put in competitive situation with the overseas enterprises and even from construction industry it follows in construction market opening and there is not another idea to the research the management strategies, directions and focus competitive elements of the enterprise against, what it sees consequently and to rise to the priority where the competitive power reinforcement of the enterprise is important, it becomes. Competitive power of like this enterprise for a reinforcement the technique which induces a big interest 6 Sigma is technique from the many companies. 6 sigma preceding researches of manufacturing and service industry the fact that it is accomplished with the object which will carry most. The research which relates with construction industry is staying to an introduction of 6 sigma the investigation phase, the actual introduction introduces and "S" construction there is not only a possibility against the application result of having a limit because it is applying. It is like that but like referring to a minute description for the international competitive power security which it follows in the change which market environment is sudden 6 sigma the introduction will judge, indispensability development of the logical propriety against hereupon and it will reach and it verifies the question investigation for to lead, 6 sigma of the construction companies it confirms the application possibility and presents the propulsion model as 6 sigma the fact that overcoming the limit characteristic of that introduction application as objective of sample research means it will do.

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Characteristic Evaluation Based on the Heat Treatment Conditions of Super Duplex Stainless Steel with 0.2% N as an Additive - Part 1: Mechanical Properties and Microstructure (0.2% N을 첨가한 수퍼 2상 스테인리스강의 열처리 조건에 따른 특성 평가 - 제1보: 기계적 특성 및 미세조직)

  • Ahn, Seok-Hwan;Kang, Heung-Joo;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
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    • v.22 no.4
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    • pp.46-50
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    • 2008
  • Super duplex stainless steel has along life in severe environments because of its strength and corrosion resistance. If 0.2$\sim$0.3% Nitrogen in aninterstitial solid solution is added, the austenite structure is reinforced. This improves the solid solution hardening and the anticorrosionability. In this study, the mechanical properties and structures of the super duplex stainless steel with the 0.2% N additive were investigated to determine the effect of various volume fractions on the austenite phase. The various volume fractions and distributions of the austenite structure in the applied test specimens were obtained by changing the heat treatment temperature and cycle. The characteristics by amounts of the $\sigma$ phase obtained from the precipitation heat treatment were alsoinvestigated. From the results, when the austenite volume fraction increases, the tensile strength decreases and elongation increases. And the $\sigma$ phase was rapidly increased by increasing the heat treatment time. When the volume fraction of the $\sigma$ phase increased, tensile strength increased.

An In-Band Noise Filtering 32-tap FIR-Embedded ΔΣ Digital Fractional-N PLL

  • Lee, Jong Mi;Jee, Dong-Woo;Kim, Byungsub;Park, Hong-June;Sim, Jae-Yoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.3
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    • pp.342-348
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    • 2015
  • This paper presents a 1.9-GHz digital ${{\Delta}{\Sigma}}$ fractional-N PLL with a finite impulse response (FIR) filter embedded for noise suppression. The proposed digital implementation of FIR provides a simple method of increasing the number of taps without complicated calculation for gain matching. This work demonstrates 32 tap FIR filtering for the first time and successfully filtered the in-band phase noise generated from delta-sigma modulator (DSM). Design considerations are also addressed to find the optimum number of taps when the resolution of time-to-digital converter (TDC) is given. The PLL, fabricated in $0.11-{\mu}m$ CMOS, achieves a well-regulated in-band phase noise of less than -100 dBc/Hz for the entire range inside the bandwidth of 3 MHz. Compared with the conventional dual-modulus division, the proposed PLL shows an overall noise suppression of about 15dB both at in-band and out-of-band region.