• Journal of Korean Society for Quality Management
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• v.32 no.2
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• pp.201-211
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• 2004

Process adjustment is a complimentary tool to process monitoring in process control. Process adjustment directs on maintaining a process output close to a target value by manipulating another controllable variable, by which significant process improvement can be achieved. Therefore, this approach can be applied to the 'Improve' stage of Six Sigma strategy. Though the optimal control rule minimizes process variability in general, it may not properly function when special causes occur in underlying process, resulting in off-target bias and increased variability in the adjusted output process, possibly for long periods. In this paper, we consider a responsive feedback control system and the minimum mean square error control rule. The bias in the adjusted output process is investigated in a general framework, especially focussing on stationary underlying process and the special cause of level shift type. Illustrative examples are employed to illustrate the issues discussed.

• Korean Journal of Materials Research
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• v.27 no.4
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• pp.211-215
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• 2017

Reactive Ion Etching (RIE) and wet etching are employed in existing texturing processes to fabricate solar cells. Laser etching is used for particular purposes such as selective etching for grooves. However, such processes require a higher level of cost and longer processing time and those factors affect the unit cost of each process of fabricating solar cells. As a way to reduce the unit cost of this process of making solar cells, an atmospheric plasma source will be employed in this study for the texturing of crystalline silicon wafers. In this study, we produced the atmospheric plasma source and examined its basic properties. Then, using the prepared atmospheric plasma source, we performed the texturing process of crystalline silicon wafers. The results obtained from texturing processes employing the atmospheric plasma source and employing RIE were examined and compared with each other. The average reflectance of the specimens obtained from the atmospheric plasma texturing process was 7.88 %, while that of specimens obtained from the texturing process employing RIE was 8.04 %. Surface morphologies of textured wafers were examined and measured through Scanning Electron Microscopy (SEM) and similar shapes of reactive ion etched wafers were found. The Power Conversion Efficiencies (PCE) of the solar cells manufactured through each process were 16.97 % (atmospheric plasma texturing) and 16.29 % (RIE texturing).

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.05a
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• pp.43-43
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• 1997

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.10
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• pp.860-863
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• 2009

YBCO bulks with fine $Y_2BaCuO_5$(Y211) particles have been prepared by the top-seed modified powder melting process method, Solid-Liquid Melt Growth(SLMG), with $Y_2O_3$, $BaCuO_2$ and CuO mixing precursor. By using $Y_2O_3$ instead of $Y_2BaCuO_5$ as precursor, the processing became to be simpler and cheaper than the current powder melting process. The microstructures, trapped field and critical current density of the various conditioned YBCO bulks have been analyzed and the effect of Pt additive was studied. The different trapped magnetic field values of the several samples have been explained in the viewpoint of their microstructures. The fabrication of large-sized YBCO single domain has been conducted.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1516-1518
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• 1998

$YBa_2Cu_3O_x$(Yl23) Superconducting thick films on $Y_2BaCuO_5$(Y211) substrate were Prepared by surface diffusion process between $BaCuO_2$+CuO composite coating powder and a Y2ll substrate. X-ray diffraction shows that the Yl23 layer onto Y2ll substrate is the orthorhombic crystal structure. The specimen heated at $940^{\circ}C$ for 2h showed the maximum $J_c$ fo 500A/$cm^2$. Based on optimal condition, the superconducting fault current limiter(FCL) having a current limiting area 1mm wide and 66mm long was fabricated on Y211 substrate. A typical current limiting waveform was measured. When a voltage of 3V was applied, the fault current with a peak of 15A was limited to about 0.11A.

• Journal of the Korean Statistical Society
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• v.32 no.2
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• pp.203-211
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• 2003

A new result of weak convergence of the empirical process is established for a stationary ${\phi}-mixing$ sequence of random variables, which relaxes the existing conditions on mixing coefficients. The result is basically obtained from bounds for even moments of sums of ${\phi}-mixing$ r.v.'s useful for handling triangular arrays with entries decreasing in size.

• Journal of Korea Technology Innovation Society
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• v.5 no.2
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• pp.189-211
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• 2002

The research shows how the technological change of 'Information and Communication Technology' (ICT) is accompanied with the usage change. It aims to provide a better conceptualization with empirical findings about the fact that the technological development of ICT is a convergence process of ICT factors with the usage of ICT moving from a limited coverage toward a general-purpose. The research adapts a descriptive methodology on a historical matter and demonstrates how it can be conducted through analytical description of Input-Output tables (I/O) the over periods. The case is about the UK with sequential I/O during 1970s- 90s.

• Proceedings of the Korean Ceranic Society Conference
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• 1986.12a
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• pp.211-225
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• 1986

Silicon carbide coating has been studied using a graphite substrate, a mixture of tetramethylsilane and hydrogen or argon at deposition temperature (T) of 950 to $1200^{\circ}C$ total pressure of 20 to 50 torr and carrier gas flow rate of 0 to 901/h. Deposition kinetic study has shown that a transition, from a surface reaction limited process to a diffusion limited one, takes place near $1100^{\circ}C$. Deposition rate depends directly upon the experimental parameters. The influence of the main process parameters is also discussed to relate the physiochemical properties of the coating to the deposition conditions.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.211-216
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• 2004

■ The objective -Design of information system supporting electronics environments ■ The Results -Environmental analysis for e-Logistics ·Analysis for logistics business process -Modeling logistics business process using UMM -Developing electronic documents ■ Concluding remarks(omitted)

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.211-213
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• 1999

In the future, restrictions are likely to be imposed on the use of lead in the electronics industry. In dealing with such a move, we have been developing Pb-free Sn-Ag plating process to replace presently available Sn-Pb process. In this paper, the result of a basic comparison test between Sn-Pb plating and Sn-Ag plating is reported.