• Proceedings of the Safety Management and Science Conference
• /
• 2010.11a
• /
• pp.27-33
• /
• 2010

The paper proposes the guidelines of application and interpretation for quality and reliability methodologies using deductive or inductive reasoning. The research also reviews Bayesian quality and reliability tools by deductive prior function and inductive posterior function.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.12
• /
• pp.705-712
• /
• 2003

In this paper, we propose new unified methodologies of reliability and its cost evaluation in power distribution systems. The unified method means that the proposed reliability approaches consider both conventional evaluation factor, i.e. sustained interruptions and additional ones, i.e. momentary interruptions and voltage sags. Because the three voltage quality phenomena generally originate from the outages on distribution systems, the basic and additional reliability indices are summarized considering the fault clearing mechanism. The proposed unified method is divided into the reliability evaluation for calculating the reliability indices and reliability cost evaluation for assessing the damage of customer. The analytic and probabilistic methodologies are presented for each unified reliability and its cost evaluation. The time sequential Monte Carlo technique is used for the probabilistic method. The proposed DVL(Demand Varying Load) model is added to the reliability cost evaluation substituting the average load model. The proposed methods are tested using the modified RBTS(Roy Billinton Test System) form and historical reliability data of KEPCO(Korea Electric Power Corporation) system. The daily load profile of the each customer type in domestic are gathered for the DVL model. Through the case studies, it is verified that the proposed methods can be effectively applied to the distribution systems for more detail reliability assessment than conventional approaches.

• Journal of the Korean Society for Precision Engineering
• /
• v.23 no.6 s.183
• /
• pp.111-118
• /
• 2006

Recently, the reliability evaluation and analysis are applied far many industrial products which are required to guarantee in quality and efficiency. The purpose of this paper is to present some of reliability evaluation methodologies that are applicable to machine tools. Especially ATC (Automatic Tool Changer), which is a core component of line center, was chosen as the target of the reliability evaluation and analysis. The scope of research is reliability prediction, reliability test and evaluates their results. The results of reliability evaluation have shown the failure rates, MTBF (Mean Time Between Failure), reliability for those components of ATC and real tests reliability through the constructed reliability test-bed. It is expected that proposed methodologies would increase reliability for a high-speed line center.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1914-1917
• /
• 2005

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 evaluation methodologies that are applicable to machine tools. Especially ATC(Automatic Too Changer), which is core component of line center, was chosen as the target of the reliability evaluation and analysis. The scope of research is reliability prediction, reliability test and evaluates their results. The results of this research has shown the failure rate, MTBF(Mean Time Between Failure), reliability for those components and real tests reliability through constructed reliability test-bed. It is expected that proposed methodologies will increase reliability for high speed line center.

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

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.28 no.1
• /
• pp.49-54
• /
• 2005

Recently, the reliability are applied for many industrial products, and many products are required to guarantee in quality and in performance. The purpose of this paper is to present some of reliability prediction methodologies using failure rate database for machinery parts that are applicable to machine tools. VDI Turret, which is core component of the NC Lathe, was chosen as the target of the reliability prediction. The results of reliability prediction has shown the failure rate, MTBF(Mean Time Between Failure), and reliability of the VDI Turret. It is expected that proposed methodologies will be applicable to prediction of reliability for other components of machine tools.

• Journal of Korean Society for Quality Management
• /
• v.34 no.1
• /
• pp.54-72
• /
• 2006

In recent years, the widespread application of quality management and measurement reliability has put increasing emphasis on procedures for periodic instrument calibration. By optimizing calibration intervals, unnecessary calibrations can be minimized, thereby reducing costs. Moreover, optimizing intervals will improve compliance with regulatory directives while ensuring maximal compliance with reliability targets. In this paper, we present Calibration Interval Analysis Program developed using several establishment methodologies of calibration interval for measurement quality and reliability improvement. Also, we perform calibration interval analysis for some measurement instruments and analyse its results.

• Proceedings of the Safety Management and Science Conference
• /
• 2010.04a
• /
• pp.253-258
• /
• 2010

The paper reviews the methodologies of confirmatory data analysis(CDA) and exploratory data analysis(EDA) in statistical quality control(SQC), design of experiment(DOE) and reliability engineering(RE). The study discusses the properties of flexibility, openness, resistance and reexpression for EDA.

• Journal of Information Technology Applications and Management
• /
• v.16 no.2
• /
• pp.23-43
• /
• 2009

For reliability and confidentiality of information security systems, the security engineering methodologies are accepted in many organizations. To improve the effectiveness of security engineering, this paper suggests a security methodology ISEM, which considers both product assurance and production processes, takes advantages in terms of quality and cost. To verify the effectiveness of ISEM, this paper introduces the concepts of quality loss, and compares the development costs and quality losses between ISEM and CC through the development of VPN system.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.3
• /
• pp.81-87
• /
• 2008

The reliability prediction and evaluation for general electronic components are required to guarantee in quality and in efficiency. Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. In this study reliability prediction of electronic components, that is the interface card, which is used in the CNC(Computerized Numerical Controller) of machine tools, was carried out using PRISM reliability prediction specification. Reliability performances such as MTBF(Mean Time Between Failure), failure rate and reliability were obtained, and the variation of failure rate for electronic components according to temperature change was predicted. The results obtained from this study are useful information to consider a counter plan for weak components before they are used.