• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.133-136
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• 2003

In these days, the reliability analysis and prediction are applied for many industrial products and many products require guaranteeing the quality and efficiency of their products. In this study reliability prediction for core units of machine tools has been performed in order to improve and analyze its reliability. ATC(Automatic Tool Changer) and interface Card of PC-NC that are core component of the machine tools were chosen as the target of the reliability prediction. A reliability analysis tool was used to obtain the reliability data(failure rate database) for reliability prediction. It is expected that the results of reliability prediction be applied to improve and evaluate its reliability. Failure rate, MTBF (Mean Time Between Failure) and reliability for core units of machine tools were evaluated and analyzed in this study.

• Journal of Applied Reliability
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• v.3 no.1
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• pp.41-58
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• 2003

Recently, the reliability evaluation and analysis are applied for many industrial products, and many products are required to guarantee in quality and in efficiency. The purpose of this paper is to present some of reliability prediction methodologies that are applicable to machine tools. Especially ATC (Automatic Tool Changer) and Interface Card of PC-NC, which are core components of the machine tools, were chosen as the target of the reliability evaluation and analysis. The results of this research has shown the failure rate, MTBF(Mean Time Between Failure), and reliability for those components. It is expected that proposed methodologies will be applicable to evaluation of reliability for other industrial products.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.375-394
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• 2008

This paper discusses two user-friendly reliability techniques that could be implemented easily using the ubiquitous EXCEL. The techniques are First-Order Reliability Method with non-Gaussian random variables expressed using Hermite polynomials and collocation-based stochastic response surface method. It is believed that ease of implementation would popularize use of reliability-based design in practice.

• Journal of Applied Reliability
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• v.1 no.1
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• pp.65-78
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• 2001

Recently, Six Sigma to increase market share , decrease costs, and grow profit margin has been adopted by some leading companies in the world. Six Sigma is expected as the optimal movement to raise the quality level remarkably and to make enterprise culture and organization based on customer and market orientation. In this paper, we study on the idea of Six Sigma, the Internal and external success case, the reliability tools using in the Six Sigma, and the difference between the existing quality movement and Six Sigma. Also, we discuss the role of reliability In Six Sigma..

• Korea Journal of Hospital Management
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• v.11 no.3
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• pp.42-55
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• 2006

The present study is designed to develop surveying tools to measure stressors of and social supports for Radiological Technologists which may play a role to alleviate their stresses caused from their job environments. For this purpose, an analysis of reliability by factors of personal stressors was conducted on 890 radiologists who are working at 44 general hospitals in 16 cities and provinces across the country. The results of the analysis may be summed up as follows: Six factors in 2 concerned fields turned out to be major tools for use as items of questionnaires to measure social supports for and organizational culture of Radiological Technologists. The factors determined to be applicable for survey with reliability coefficient of more than 0.7 measured by factors for internal coherence included social supports on the job(0.90), off-the-job social supports(0.81), job satisfaction(0.80), devotion for job by length of service(0.81) and emotional devotion for job(0.80), all deemed to be appropriate as survey items. In the verifying process of the results, it was found that normative devotion for job(0.61) showed lower reliability as its statistical coefficient was analyzed to be less than 0.7. It seemed, therefore, necessary to reconstruct items or re-select such ones only that can maintain internal coherence in order to analyze appropriateness of related measuring tools, or to develop new measuring tools. Although the outcomes of this study can be used to verify reliability and appropriateness of concerned concepts to assess stresses caused during the job performance of Radiological Technologists, it may be improper to adopt them to measure all types of social supports and stresses that occur generally under the job environment. It is desired, however, to compare and analyze the findings of the present study with others and to utilize them as basic data for further development of tools that can maintain internal coherence in terms of reliability and appropriateness in spite of changing social environments.

• Journal of Korean Society for Quality Management
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• v.50 no.3
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• pp.571-591
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• 2022

Purpose: The purpose of this study is to examine the factors affecting the intention to use online collaboration tools for non-face-to-face educational environment in the perspective of the learners. Methods: For empirical analysis, the survey of this study was administered with data that were limited to experienced learners using online collaboration tools such as Google Docs, Allo, Padlet, and Slido in online education environments such as Zoom, Webex, MS Teams, etc. and valid 400 data were analyzed by SPSS(ver 22.0) and R(ver 4.1.0) program package. Results: The results of empirical analysis showed that performance expectancy were found to have an effect on reliability of system quality, empathy of service quality, playfulness and informativity of content quality among the characteristics of online collaboration tools. On the other hand, it was found that the security of system quality, responsiveness of service quality, and extroversion of user personality characteristics did not affect. It was analyzed that playfulness had the greatest positive effect, followed by informativity, empathy, and reliability. Among the characteristics of online collaboration tools, it was found that the reliability and security of system quality and informativity of content quality had an effect on the effort expectancy. It was analyzed that informativity has the greatest influence, followed by security and reliability. Conclusion: This study is meaningful in that it examines the perspectives of users and learners, who can be said to be the end customers of online collaboration tools. Based on the results of this study, it is expected that not only platform operators that provide online collaborative tools, but also providers that use online collaboration tools will have a significant impact on the development of edutech and infrastructure in the educational environment.

• Journal of Korean Clinical Nursing Research
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• v.16 no.3
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• pp.5-23
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• 2010

Purpose: This study was conducted to determine the validity and reliability of performance measurement tools based on the nursing process for prevention and management of pressure ulcers, falls and pain. Methods: The performance measurement tools were reviewed by a panel of experts and refined on the basis of the panel's suggestions. The validity of the performance measurement tools was measured by surveying hospital nurses. The reliability of these tools was tested by having nursing experts use the tools in five nursing units to assess nursing performance in prevention and management of pressure ulcers, falls and pain. Results: The performance measurement tools in this study were found to be acceptable as tools to evaluate quality of nursing care in pressure ulcers, falls and pain. The reliability of the performance measurement tools was acceptable. Conclusion: These results indicate that the performance measurement tools developed in this study are valid and reliable instruments to monitor and improve quality of nursing care in prevention and management of pressure ulcers, falls and pain.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.3
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• pp.1-7
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• 2005

The prediction for tool life is one of the most important factors for increasing reliability, stability, and productivity of manufacturing system. This paper deals with a tool life prediction method in view of reliability assessment for cutting tools. In this study, flank wear was focused among multi-factors deciding the tool wear state. First, tool life was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning, including parameters of cutting speed, feed rate, and cutting depth. Second, each of cutting conditions of end-milling was equivalently converted to apply ball end-mill data to the extended Taylor equation. The web-based prediction program for tool life was developed as one of reliability assessment programs for machine tools.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.369-374
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• 2004

Web-based analysis programs for reliability assessment of machine tools were developed in this study. First, the reliability data analysis program was developed to search for failure rate using failure data and reliability test data of mechanical part. Second, failure mode analysis was developed through performance tests like circular movement test vibration test for machine tools. This analysis program shows correlation between failure mode and performance test result. Third, tool life was predicted by correlation between flank wear and cutting time, using the extended Taylor tool life equation in turning data and the equivalently converted equation in order to apply ball endmill data to Taylor tool life equation in milling data. All the information related to input and result data can be stored in theses programs.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.1
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• pp.15-23
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• 2005

For reliability assessment for machine tools, failure mode analyses by two viewpoints were studied in this paper. First, this study developed the reliability data analysis program, which searches f3r optimal failure distribution like failure rate or MTBF(Mean Time Between Failure) using failure data and reliability test data of mechanical parts in the web. Moreover, this data analysis program saves both failure data or reliability data and their failure rate or MTBF for database establishment. Second, this paper conducted failure mode analysis through such performance tests as circular movement test and vibration testing for machine tools when reliability data is not available. A developed web-based analysis program shows correlations between failure mode and performance test result and also accumulates all the data. These kinds of data analysis programs and stored data furnish valuable information for improving the reliability of mechanical system.