• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.1035-1036
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• 2005

• Journal of the Korean Society of Systems Engineering
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• v.11 no.2
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• pp.125-135
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• 2015

Various methods have been used for safety and reliability as it becomes more difficult to ensure safety owing to the increasing complexity and scale of systems. This study aims at making it easier and more efficient to discuss risks and countermeasures for completeness, review, and knowledge transfer by improving methods to create fault tree analyses which focus on the GSN [1], which are among the methods used to describe assurance cases. More specifically, the purpose of this study is to incorporate strategy and context, GSN concepts, along with reason, which is a new concept, into FTA; the study focuses on three points. One point is support for the safety designer to draw a mutually exclusive and collectively exhaustive (MECE) FTA. The second is to make it easier to understand diagrams and meanings of FTA compared with the usual methods. The third is to make creating an FTA more efficient and to pass on existing know-how. Eventually, FTA can achieve completeness, review, and knowledge transfer. An introduction is provided in the first section. Next, the methodology covered in this paper is explained in the second section. The third section describes the proposed notation method based on two proposals made in this paper. In the fourth and fifth sections, results and discussion are provided, respectively. Finally, in the sixth section, conclusions are described.

• Journal of Korean Institute of Industrial Engineers
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• v.33 no.2
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• pp.191-200
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• 2007

We propose the QoS (Quality of Service) assurance model for AMR (Adaptive MultiRate) voice users considering the capacity and service quality jointly in downlink WCDMA system. For this purpose, we introduce a new system performance measure and the number-based AMR mode allocation scheme. The proposed number-based AMR mode allocation can be operated only with the information of total number of ongoing users. Therefore, it can be more simply implemented than the existing power-based allocation. The proposed system performance measure considers the stochastic variations of AMR modes of ongoing users and can be analytically obtained using CTMC (Continuous Time Markov Chain) modeling. In order to validate the proposed analytical model, a discrete event-based simulation model is also developed. The performance measure obtained from the analytical model is in agreement with the simulation results and is expected to be useful for parameter optimization.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.207-216
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• 2004

IPsec protocol has been developed to provide security services to Internet. Recently IPsec is implemented on the various operating systems Hence, it is very important to evaluate the stability of the Ipsec protocol as well as other protocols that provide security services. However, there has been little effort to develop the tools that require to evaluate the stability of IPsec protocols. Therefore, in this paper, we develope the security requirements and suggest a security evaluation system for the Internet packet protection protocols that provide security services at the If level that can be used to check if the security protocols Provide the claimed services correctly This system can be used as debugging tool for developing IPsec based security system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.551-554
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• 2012

KARI is now developing KSLV-II which can insert 1.5ton satellite into the orbit, and system design review is close at hand. As a part of mission assurance for space launch vehicle, reliability and safety management is being performed and to assure the safety, KARI has been doing actions on the basis of the safety assurance plan and system safety program plan. In this study, preliminary hazard analysis is reviewed and the result for the propulsion system will be illustrated. The result will be used as a reference for the safety and risk management.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.12 no.4
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• pp.345-361
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• 2014

The systematic quality assurance activities on documents of the safety assessment are required for the safety case of the low- and intermediate-level radioactive waste disposal facility. In this paper, quality assurance system focused on the input data including the site characterization, groundwater flow, system design and monitoring are prepared and discussed. Rule for the input data selection is suggested and applied for the safety assessment which is based on the in-situ/experiment observations, final facility design and waste pileup plan, engineered barrier, field monitoring, recent biosphere, and radionuclide inventory. The reduction of data uncertainty will be expected to contribute to the safety of disposal facility further.

• Journal of Pharmaceutical Investigation
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• v.37 no.6
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• pp.329-338
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• 2007

The quality assurance issue of drug products is more important than the general product because it is highly related to the human health and life. In this reason, the regulatory guide lines have continuously been intensified all around the world. In order to achieve effective quality assurance and real-time product release (RTPR) of drug products, process analytical technology (PAT), which can analyze and control a manufacturing process, has been proposed from the United States. With the PAT process, we can obtain significant process features of materials, quality characteristics and product capabilities from a raw material to the final product in the real-time procedure. PAT can also be utilized to process validation using information system that can analyze the risk of drug products through out an entire product life-cycle. In this paper, we first offered a new concept for the off-line process design methods to prepare the improved quality assurance restrictions and a real-time control method by establishing an information system. We also introduced an automatic inspection system by obtaining surrogate variables based on drug product formulations. Finally, we proposed an advanced PAT concept using validation and feedback principles through out the entire life-cycle of drug product manufacturing processes.

• Quality Improvement in Health Care
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• v.18 no.1
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• pp.71-78
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• 2012

Background : The objective of this study was to examine the effect of management system for the appropriate prophylactic use of antibiotics in surgical patients at a tertiary hospital from 2007 to 2010. Methods : We collected clinical data of three different surgical procedures(colectomy, heart surgery, hysterectomy) for three months of 2007 and 2010, respectively. The number of total cases was 245(137, 54, 54) in 2007, 240(133, 42, 65) in 2010. We measured the rate of use of inappropriate prophylactic antibiotics, administration within 1 hour prior to the incision and the antibiotics prescription days after surgery. To evaluate the effectiveness of the management system, the results of the two groups(Group1=2007, Group2=2010) were compared by t-test, chi-square test or Fisher's exact test. Result : The rate of Aminoglycoside uses decreased drastically from 11.4% to 0.8%(P<.001). The selection of 3rd/4th Cephalosporin dropped from 11.8% to 5.8%(P=.020). The combination of antibiotics decreased from 27.8% to 11.7%(P<.001). The antibiotic prescription rate on discharge declined from 11.8% to 2.5%(P<.001) and the number of antibiotics prescription days after surgery was shortened from 4.2 days to 2.3 days(P<.001). No significant difference in the rate of administration within 1 hour between two groups was found. Through 3-year management, 5 out of 6 measures were significantly improved(except the administration within 1 hour). The rate of surgical site infection decreased from 2.4% to 1.3%(P=.504). Conclusion : The findings demonstrate that the management system for the prophylactic use of antibiotics in surgical patients was effective in decreasing the rate of surgical site infection during 3 years.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.621-628
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• 2010

Quality assurance data is used to develop the strategy of the product since it is valuable for reliability assessment of the product. However, manufacturers don't take into account the life of the product but just produce WCR (Warranty Call Rate) which is monthly or quarterly claims per 1000 products in terms of table or graph. In this study we will consider how they analyse that kind of data and suggest an appropriate type of analysis which incorporates the life time of the product. Finally we emphasize that the appropriate type of analysis has to be merged into the.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.457-463
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• 2013

Purpose: For effective quality assurance activities, BOM-based quality assurance method is presented. This study introduces various BOM conversions such as Q-BOM, T-BOM, and S-BOM based on M-BOM structure. Methods: Product quality control via Q-BOM manages inspection/audit information, overall supply-chain of product, part requirements, and inventory status. T-BOM manages part traceability, and S-BOM enables statistical control over key process and parts at various hierarchy levels. Results: Quality plan template was developed based on the study results of BOM system including Q-BOM, T-BOM, and S-BOM. Conclusion: Through BOM(Q-BOM, T-BOM, and S-BOM) study and development of quality plan template, more systematic and comprehensive quality management plan is achieved.