• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.368-375
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• 2014

The Ground Based Augmentation System (GBAS) is influenced by environmental factors, making analysis in the installation region important. This study has proposed the sigma inflation of the B-value considering the satellite elevation angle and analyzed the Vertical Protection Level (VPL) of the H1 hypothesis. After collecting data that meet the environmental conditions of the installation region, sigma expansion coefficients by the unit of satellite elevation angle ($5^{\circ}$) have been estimated. The obtained results were functionalized through curve-fitting, and sigma inflation customized for the environmental conditions of the test region was proposed. Then, the characteristics were classified and analyzed depending on humidity and solar activities. According to the sigma inflation with respect to elevation angle analysis, changes in the size of sigma inflation factors by the difference of humidity were minor. However, the VPL under the satellite elevation angle-based sigma inflation met integrity. Also, considering the sigma inflation factor with respect to elevation angle, compared to existing methods, high-integrity and improved availability is confirmed by removing unnecessary margins in high elevation angle satellite.

• Survey Research
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• v.8 no.1
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• pp.1-30
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• 2007

Several corporations are adopting the 6 Sigma program. Not all corporations are yielding intended results. The inconsistent results may due to the absence of an adequate strategy formulation of 6 Sigma implementation. The 6 Sigma is a qualify control program but its implications are not confined only to qualify improvement. The 6 Sigma program is a change program to bring about changes in organizations. The thesis focuses on developing an installation strategy or model of 6 Sigma program. The utility of the model developed in this research is supported by the empirical evidence. The validity of the model is tested and verified based on the questionnaire survey conducted at 281 business firms. Few research has adopted the empirical survey. The previous researches are mostly centered around identifying success factors. Unlike the present methodology adopted in this research, the past research methodologies are mainly case studies. The distinctive feature of this research does not confine only to the methodology. This research attempted to identify an installation model that would help enterprises get maximum output from the 6 Sigma program. The suggested model is named as Sequential Model(SM). The SM consists of three stages: the preparation stage, the acceptance stage, and the maturity stage. The model is based on the assumption that organizations should follow three stages sequentially to yield the desired output effectively, The preparation stage is further defined including the organizational change factor, the driving system factor, and the promotion factor. The result variable, the organizational performance, is also further defined including the market competitiveness, the employees competitiveness, and the financial performance. The Structural Equation Model was used to test the validity of the Sequential Model(SM). Several alternatives models were developed and compared. The test results consistently show that the suggested model is a valid one and proves its superiority over alternative models. Through this empirical research, we have shown that the strategies of enterprises in line with the proposed model gained better results over others. The research results would be useful information for enterprises that consider formulation of installation strategy of 6 Sigma program.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.06a
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• pp.243-250
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• 2000

In the partial lubrication regime, the roughness effects are most important due to the presence of interacting asperities. An average Reynolds equation using flow factors is very useful to determine effects of surface roughness on partial lubrication. In this paper, the pressure flow factors for Gaussian and non-Gaussian surfaces are evaluated in terms of kurtosis. The effect of kurtosis on pressure flow factor is investigated using random rough surface generated numerically. The pressure flow factor increases with increasing kurtosis in partial lubrication regime(h/$\sigma$<3). As h/$\sigma$increases, the pressure flow factor approach to 1 asymptotically regardless of kurtosis.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.333.2-333
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• 1998

No Abstract, See Full Text

• Journal of Korean Society for Quality Management
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• v.36 no.3
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• pp.45-54
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• 2008

For successful accomplishment of six sigma innovation, one of the most important factor is performance evaluation and proper compensation. Six sigma project teams are well motivated to perform the projects only when their activities are properly evaluated and reasonable compensations are secured. In this paper, a systematic evaluation system of financial effect of six sigma projects is presented for order-based aerospace industry.

• IE interfaces
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• v.20 no.3
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• pp.315-326
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• 2007

The service industry is becoming greater importance in the current economy. The service quality has become an important competitive factor in service industry. Until now, 6 sigma method has well accomplished in manufacturing industry. 6 sigma method has been applied to the service industry to improve service quality, but it has not been reported that 6 sigma method is a successful method for service industry to improve service quality. In this paper, we suggest a MAVIC model to improve service quality. It is a model which is combined with advantages of a SERVQUAL model and 6 sigma method. We has proved its effect with applying a MAVIC model to real service techniques.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.179-187
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• 2012

This paper presents a six sigma application case study for an automobile PCSV manufacturing process using rolled throughput yield improvement activity. Hidden factor and first yield concept is introduced and DMAIC procedure is implemented to maximize the first pass yield. The result of the six sigma project amounts to the reduction of failure cost of 0.1 billion won per year in the PCSV manufacturing process. This paper can benefit six sigma practitioners in some ways.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.65-76
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• 1992

The superoxide dismutase (SOD)-mimetic activities of copper complexes of a series of salicylic acid (SA) analogs were tested and compared to the activity of bovine erythrocyte SOD using ferricytochrome c reduction assay. Stability constants of copper complexes were measured potentiometrically using SCOGS2 program. In the presence of 10 g/l albumin, all the copper complexes lost their SOD mimetic activities. Multiple regression analysis was employed for the statistical comparisons between the SOD mimetic activity and their physicochemical properties. Correlation exists for the SOD mimetic activity and steric parameter $(E_s)$ and/or electronic parameter $({\Sigma}{\sigma})$ in xanthine/xanthine oxidase (XOD) system, demonstrating that E, plays a key role in SOD activity whereas ${\Sigma}{\sigma}$ influences it to a lesser extent. The protective effect of copper complexes against membrane damage was measured by counting D-glucose released frm $EG_s$. D-glucose and XOD were entrapped within $EG_s$ and acetaldehyde was used as a substrate for XOD. In this membrane model system using $EG_s$, hydrophobic parameter $({\Sigma}{\pi})$ is of most importance, producing parabolic equation while $E_s$, and ${\Sigma}{\sigma}$ appear to playa minor role in protection against D-glucose release. In summary, to design an efficient SOD mimetic, stability, steric factor, lipophilicity and redox potential should be considered.

• Journal of Ocean Engineering and Technology
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• v.7 no.2
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• pp.19-29
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• 1993

The static tensile tests of GFRP, ID300, CFRID300 and CFRPEEK were made on the plain and notched specimens at room temperature. The results were discussed based on linear notch mechanics which was proposed by H.Nistani. The fracture of notched GFRP, ID300, CFRID300 and CFRPEEK specimens is controlled by the elastic maximum stress, $({\sigma}_max)$, and the notch root racius,$\rho$, alone, independently of the other geometrical conditions. The relation between fracture nominal stress,$({\sigma}_max)$, and stress concentration factor, $K_t$ and a part where $({\sigma}_c)$ is nearly constant independent of $K_t$. A similar phenomenon can be seen in the fatigue tests of notched specimes under rotating bending or push-pull. The almost constant $({\sigma}_c)$ values correspond to the nearly constant apparent stress intensity factor, $K_{1pc}$ values, obtained by assuming ,$\rho$=0. This can be attributed to the existence of the stable crack. Linear notch mechanics is very useful for analyzing the static tensile fracture behavior of notched GFRP, ID300, CFRPEEK specimens.

• Tribology and Lubricants
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• v.16 no.6
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• pp.448-454
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• 2000

The roughness effects are very important due to the presence of interacting asperities in partial lubrication regime. An average Reynolds equation using flow factors is very useful to determine the effects of surface roughness on mixed lubrication. In this paper, the pressure flow factors for surfaces having Gaussian and non-Gaussian distribution of roughness height are evaluated in terms of various kurtosis. The effect of kurtosis on pressure flow factors is investigated using random rough surface generated numerically. The pressure flow factor increases with increasing kurtosis in mixed lubrication regime (h/$\sigma$<3). As h/$\sigma$ increases, the pressure flow factors approach to 1 asymptotically regardless of kurtosis.