• Communications for Statistical Applications and Methods
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• v.11 no.1
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• pp.181-187
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• 2004

One of objectives in epidemiologic studies is to detect the amount of change caused by a specific risk factor. Risk ratio is one of the most useful measurements in epidemiology. When we perform the inference for this measurement with rare events, the standard approach based on the normal approximation may fail, in particular when there are no disease cases observed. In this paper, we discuss and evaluate several existing methods for constructing a confidence interval of risk ratio through simulation when the disease of interest is a rare event. The results in this paper provide guidance with how to construct interval estimates for risk difference and risk ratio when there are no disease cases observed.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.335-337
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• 1993

Offset voltage and drift characteristics of operational amplifier are critical factor to precision AID conversion System. In this study, a method is suggested to design the programmable A/D conversion system which has high resolution and low drift characteristics. First, hardware was designed to reduce the offset voltage of integrator and comparator, and analog switches are connected to reduce the drift characteristics of operational amplifier. And then, a calibration software technique was performed to obtain the stable data from A/D converter. The main advantage of our method is high precision A/D converter can be constructed with low cost and high confidence. Therefore proposed method is expected to be used in the industrial field where a high precision measurement is required.

• Journal of the Korean School Mathematics Society
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• v.5 no.1
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• pp.1-11
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• 2002

The purpose of this study is to find out if there are meaningful differences between small rural middle schools and nearby urban ones In the mathematical diagnostic evaluation. It also says how to improve students' scholastic abilities, making up a question of attitudes towards math to know the mathematical abilities lowering cause in small rural middle schools. Findings are, 1. Students must recognize that studying math is essential and be interested in it. 2. The mathematical confidence is needed. 3. A strong will of studying math hard is important. 4. Students must have a motivational triggering, while solving math problems and then checking answers for themselves. 5. Backward countries' humanistic and social environmental factors should be overcome. In conclusion, we expect the mathematical abilities improvement, making students remove the mathematical abilities lowering cause after having a learning experience suitable for the rural community instead of the negative attitudes towards math.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1056-1061
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• 2007

Railroad roadbed was consisted into structure types that earthwork, tunnel, bridge and joint sections. Joint section was affected a large factor confidence and safety of the train running by stiffness transition zone that track substructure stiffness change section as like between tunnel and earthwork from ballast track to concrete track. These problems are the results of increased dynamic wheel loads, which also lead to wear and tear on vehicle components and contribute to poor ride quality. The study presented in this paper was conducted on model test by using Wheel Moving Loading System.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.191-198
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• 2014

PURPOSES : Safety consciousness can be the first factor to hinder the acceptance of design alternative, which moderates the applied design criteria in order to adapt the road to the natural terrain condition. METHODS : The method which enables to check the safety of design alternative by using design consistency concept is suggested. The method is based on the linked or interactive analysis between terrain and road alignment. Real design example is considered as a guide how to apply the method and the analysis result is discussed with the future research. RESULTS : Suggested method can be used for designers as a tool to review their design outputs can be safe as much as the original design. So, designers have the more objective judgement on their designs and have the confidence on their designs. CONCLUSIONS : The method is expected to be used as a tool to see the safety consciousness in an objective view, so any possible conflicts between designers and design-related personnels caused by the terrain-oriented design can be solved.

• Fashion & Textile Research Journal
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• v.3 no.2
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• pp.148-155
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• 2001

The purpose of this study was to segment the clothing customers of new traditional market according to shopping orientation and to clarify the different clothing behaviors among segmented groups. This study may be useful for new traditional marketer to make proper marketing strategies. The subjects for the final analysis were 400 customers who visited Namdaemoon and Dongdaemoon new traditional markets. The statistics used for analysis were factor analysis, cluster analysis, Cronbach-${\alpha}$, one-way ANOVA, LSD multiple range test and chi-square by the SPSS program. The results of this study were as follows: 1. The customers of new traditional market were segmented to 5 groups (Diffidence Group, Confidence/Information Group, Active Group, Shop/Brand Loyalty Group and Planned Purchasing Group); 2. The five segmented groups were significantly different in clothing evaluation standards, shop evaluation standards, satisfaction and demographic variables such as sex, age, education and monthly spending money.

• The Research Journal of the Costume Culture
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• v.9 no.1
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• pp.86-99
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• 2001

The purpose of this study was to identify and profile store browsers in terms of their browsing motives, fashion behavioral characteristics, buying behavior and preferred store attributes. The data were collected through questionnaire from 302 female college students by convenient sampling method. Statistical analysis of factor analysis, x²-test, and t-test were performed in analyzing the data. The browsing motives of browsers were to obtains fashion information, sensory stimulation and diversion from routine life. They showed the high level of fashion involvement, shopping confidence, shopping innovativeness, shopping opinion leadership as well s fashion opinion leadership. Browsers tended to be impulse buyers and spent more money on clothing than non-browsers. The attributes that influence their store choice were the variety of products and brands, information availability ,and pleasant store atmosphere.

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.2
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• pp.31-45
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• 2002

The purpose of this study was designed to investigate if self-monitoring variable among various individual trait theories and demographic variable would be variables which can explain about the importance differences of consumer service level of retailing in the garment product. The survey was conducted from Feb, 6 to 16, 2002. For this survey, the 118 data were analysed with spss window 9.0 version and Cronbach's, Factor analysis, one-way ANOVA, Duncan test, Frequency, mean, percentage were applied. The results of this study were as follows; 1. Consumer service was classified in attitude/confidence/expert knowledge of salesperson, product display, product information, product assortment, shopping environment, lighting setup. 2. As a result of analyzing the importance differences per consumer service dimension depending on self-monitoring levels, it was not significant differences. 3. As a result of analyzing the importance differences per consumer service dimension depending on demographic variables, it was not significant differences.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2109-2111
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• 1998

This paper proposes a new lossless snubber circuit on power supply for welding machine's output rectification diode. To improve the common inverter control type power supplies' problems that energy loss and heating in the snubber circuit because the output capacity makes too big heat energy in the circuit when the output current of the inverter is rectified by the diode bridge circuit, which includes the snubber circuit. This paper suggested new snubber circuit have increased power factor and confidence of output by being regenerate thus lost energy to input node.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.102-108
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• 2005

Single PPM Quality Innovation Movement is originally developed quality program in Korea for supplier's quality level-up since 1995. The quality target is below the 10ppm(parts per million) in outgoing quality and delivered goods plus field claim. Recently 1,053 companies is received Single PPM Quality Certification from government. This quality program is to realized the anticipated results not only duality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 75 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade S-PPM, and suggest a way out of difficulties.