• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.3
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• pp.179-192
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• 2008

A multiphase compensation method with mismatch linearization technique, is presented and demonstrated in a $\Sigma-\Delta$ fractional-N frequency synthesizer. An on-chip delay-locked loop (DLL) and a proposed delay line structure are constructed to provide multiphase compensation on $\Sigma-\Delta$ quantizetion noise. In the delay line structure, dynamic element matching (DEM) techniques are employed for mismatch linearization. The proposed $\Sigma-\Delta$ fractional-N frequency synthesizer is fabricated in a $0.18-{\mu}m$ CMOS technology with 2.14-GHz output frequency and 4-Hz resolution. The die size is 0.92 mm$\times$1.15 mm, and it consumes 27.2 mW. In-band phase noise of -82 dBc/Hz at 10 kHz offset and out-of-band phase noise of -103 dBc/Hz at 1 MHz offset are measured with a loop bandwidth of 200 kHz. The settling time is shorter than $25{\mu}s$.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.20-25
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• 2000

lh deleterious Cr, Mo rich -$\sigma$phase is a hard embrittling precipitate, which forms between MU)-900 $^{\circ}C$, often associated with a reduction in both impact properties and corrosion reshame. On this study, After aging at MU) "C, fatigue crack propagation induced by a phase precipitation was evaluated and time-frequency analysis of acoustic emission was conducted It was possible to find fracture mechanism by a phase precipitation due to time-frequency anulysis of acoustic emission signals.nals.

• Korean Institute of Interior Design Journal
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• v.16 no.2 s.61
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• pp.322-330
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• 2007

Because 6sigma is doing innovative success In management whole, estimate that can exert direct effect in interior Design management. Therefore, this study did by purpose that 6sigma that is scientific method that do customers satisfaction by ultimate purpose acts as basic study that can heighten practical use Possibility and result of interior Design management and value by interior design standardization process. Need to use marketing data that is scientific design component at schematic design step for successful interior design that can improve result. Hereupon, this study is doing to big dimension that utilizes 6sigma and makes standard process of only Interior Design, and did to dimension that present study phase verifies if '6sigma' is practical use possibility by intoner design process. Did by method that verification method of 6sigma practical use possibility analyzes "Information transmission efficiency improvement of department store display space" 6sigma project example. When see that example project is analyzed on Improvement constituent that "Design improvement" out of Vital few Xs of statistical analysis item must heighten the customers satisfaction rate conclusively, target process might be established because design becomes center of gravity if did design improvement very first time. Finally, possibility that 6sigma can utilize in process of interior design is verified, and it is scientific methodology that can utilize to all business members that there are not any special category of business even if is in practical use. Such scientific 6sigma method need persistent study that make standard process analyzing a lot of problems that is expected to be beaconed and happens substantially in here after to management development of interior design.

• Journal of Korean Society for Quality Management
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• v.36 no.4
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• pp.37-46
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• 2008

There are big differences in six sigma projects between manufacturing processes and transactional/service processes. This paper analyzed the differences between the two areas by examining 18 six sigma case studies in Korean companies. To characterize six sigma case studies, step-by-step questions and check criteria were developed based on 12 step DMAIC methodology. On the basis of those characterized data, the differences between two areas were analyzed. Significant differences were found in the number of CTQs, validation of measurement systems, methods to determine improvement objectives, the methods to elicit improvement plans and types of control systems. The most significant difference was that statistical tools were widely used in manufacturing processes, but qualitative tools were used in transactional/service processes during improvement phase.

• IE interfaces
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• v.16 no.spc
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• pp.7-13
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• 2003

This paper is concerned with a six sigma green belt training program. Comparative studies of existing training programs for three major companies (Samsung Electronics Company, Hyundai Motor Company, and LG Chemical Ltd.) and two consulting firms (Korean Standards Association and Korea Management Association) are made. Based on the comparative studies, a new green belt training program is proposed. The main focus of this program is on manufacturing, specially on cost and waste reductions, yield improvement, and operations with opportunity to improve capacity without major capital expenditure. The green belts take up to 4 or 5 days of intensive, highly quantitative training, roughly corresponding to the five macro phases of the six sigma methodology: define, measure, analyze, improve, and control. The six sigma tool sets for each phase are also specified.

• Research in Plant Disease
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• v.30 no.2
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• pp.148-156
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• 2024

Ralstonia pseudosolanacearum, a plant pathogenic bacterium that can survive for a long time in soil and water, causes lethal wilt in the Solanaceae family. Sigma S is a part of the RNA polymerase complex, which regulates gene expression during bacterial stress response or stationary phase. In this study, we investigated the role of sigma S in R. pseudosolanacearum under stress conditions using a rpoS-defective mutant strain of R. pseudosolanacearum and its wild-type strain. The phenotypes of rpoS-defective mutant were complemented by introducing the original rpoS gene. There were no differences observed in bacterial growth rate and exopolysaccharide production between the wild-type strain and the rpoS mutant. However, the wild-type strain responded more sensitively to nutrient deficiency compared to the mutant strain. Under the nutrient deficiency, the rpoS mutant maintained a high bacterial viability for a longer period, while the viability of the wild-type strain declined rapidly. Furthermore, a significant difference in pH was observed between the culture supernatant of the wild-type strain and the mutant strain. The pH of the culture supernatant for the wild-type strain decreased rapidly during bacterial growth, leading to medium acidification. The rapid decline in the wild-type strain's viability may be associated with medium acidification and bacterial sensitivity to acidity during transition to the stationary phase. Interestingly, the rpoS mutant strain cannot utilize acetic acid, D-alanine, D-trehalose, and L-histidine. These results suggest that sigma S of R. pseudosolanacearum regulates the production or utilization of organic acids and controls cell death during stationary phase under nutrient deficiency.

• Korean Journal of Metals and Materials
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• v.49 no.3
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• pp.197-202
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• 2011

This study was carried out to investigate the precipitation behavior of ${\chi}$ phase and effect of ${\chi}-phase$ which precipitated at the initial stage of aging on mechanical properties of 25%Cr-7%Ni-4%Mo-0.2%N super duplex stainless steel. ${\chi}-phase$ was precipitated mainly at the interface of ferrite / austenite phases and inside of the ferrite phase at the initial stage of aging, and it was transformed into ${\sigma}-phase$ with an increase of aging time. The ferrite phase was decomposed into new $austenite({\gamma}_2)phase$ and ${\sigma}-phase$ by aging treatment. The hardness and tensile strength of the initial stage of aging when ${\chi}-phase$ was precipitated did not changed considerably, while elongation rapidly decreased. Accordingly, it is considered that ${\chi}-phase$ didn't affect the hardness and strength significantly, but it affected the elongation.

• Journal of Energy Engineering
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• v.19 no.1
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• pp.51-56
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• 2010

Due to increase in oil price unstableness and earth warming, energy saving has been one of the most important global issues. We report a 6 sigma project that was carried out to save electrical energy in a university campus. DMAIC, the five-phase process of 6 sigma, was applied for the energy saving campaign. This paper proposes a simple method to quantify the sigma level of the electrical energy saving status and various activities to change the consciousness of all the university members. Results were very satisfied. The 6 sigma project saved about 10% of the total electrical consumption. This is approximately 50 million won a year. The success of the 6 sigma project served as a momentum to promote "Green Scholarship" that has become the center of public interest. Also, we have valuable experiences in the 6 sigma training that shows the university campus can be successfully used as a good place for the actual 6 sigma training.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.9-15
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• 2005

The polariscope to measure the microscopic stress in CR lens consists of light source polarizer, model, polarizer, CCD, computer, chrome conversion orderly and the principal-stressed difference, (${\sigma}_1-{\sigma}_2$) and the fringe order n were measured by analyzing two components of light wave $E_1$ and $E_2$ following each polarizer's steps. The two-dimensional model could be determined from the fact that the optical axes of sample concide with the principal-stress directions. The bi-refringence acted to a light wave and the phase retardation were in proportion to the principal-stressed difference(${\sigma}_1-{\sigma}_2$) and the intensity of final light wave was proportioned to $sin2({\Delta}/2)$ and when ${\Delta}/2=n{\pi}$ (n=0, 1, 2, ${\ldots}$) the extinction occurs. Photoelastic's image by microscopic stress could analyzed using chrome conversion, and the image showed clearly.

• Journal of Korean Society for Quality Management
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• v.33 no.3
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• pp.135-148
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• 2005

This paper considers a six sigma project for reducing the project costs through project risk management. The project follows a disciplined process of five phases: define, measure, analyze, improve, and control. A risk management process map is used to identify process input and output variables. Seven key process input variables are selected by using C&E diagram and X-Y matrix and finally four vital few input variables are selected by the related statistical analysis. The optimum alternatives of the vital few input variables are obtained by the method of PUGH matrix. The process is running on control plan and we obtained substantial project cost reductions in early stage of the control phase.