• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.277-287
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• 1996

Based on the developments of the reliability-based steel structural analysis and design as well as the extending knowledgy on the probabilitic characteristics of loading and resistance the probability based design criteria have been successful Iy developed for many students. The existing design codes, which are genarally based on the structural theory and certain engineering experience, do not realistically consider the uncertainties of loads and resistance and the basic reliability concepts. It is recognized to develope the design criteria by ETCM(Expected Total cost Minimization). In this study, therefore, the proper probability based design criteria (Optimum load and resistance factor design formats ) has been developed based on the safety levels observed from calibration Iii th existing standards, which applies to the ultimate limit states of steel structural members.

• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.40-47
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• 2006

Claim history data of rather long period were collected to assess reliability and warranty cost analyses. The data were appropriately organized to be used for further statistical analyses. For each critical component, nonparametric statistical method was applied to obtain reliability plot. Hazard plots of the components in a subsystem or system level were also obtained. Competing risk model was assumed to obtain the performance of the subsystem or system level.

• Korean Management Science Review
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• v.18 no.2
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• pp.11-24
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• 2001

To cope with the rapid emergence of competition, communication service providers are assigning marketers for the purpose of relationship marketing. However, the efficiency of relationship marketing has yet to be examined. This paper investigates the service quality determinants In relationship marketing through the telecommunication service marketers. By considering the specificity of the marketer´s role, the quality dimensions in SERVQUAL research have been modified. A survey has been conducted for the hypothesized seven quality dimensions. The results of the factor analysis show that the service quality determinants of relationship marketing are in fact four dimensions : empathy, reliability, image and tangibles. Here, the empathy dimension entails cost factor, and the reliability dimension includes responsiveness and assurance. The results also support the proposition, reported in SIRVPIRF research, that the quality of service should be measured only by the perceived achievement of the customer. This study provides useful insights into developing the strategy for effective relationship marketing.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2222-2224
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• 2002

Induction motors are critical components of many industrial machines and are frequently integrated in commercial equipment. The heavy economical losses and the deterioration of system reliability might be caused by the failure of induction motors in industrial field. Based on the reliability and cost competitiveness of driving system (motors), the faults detection and diagnosis of system is considered very important factors. In order to perform the faults detection and diagnosis of motors, the vibration monitoring method and motor current signature analysis (MCSA) method are emphasized. In this paper, MCSA method are used for induction motor fault diagnosis. This method analyzes the motors supply current. since this diagnoses faults of the motor. The diagnostic algorithm is based on the artificial neural network, and the diagnosis system is programmed by using LabVIEW and MATLAB.

• Journal of the Korea Safety Management & Science
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• v.9 no.6
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• pp.69-79
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• 2007

Corporations are faced with the key strategic task of adopting a comprehensive management system of a new paradigm in order to enhance their products' quality, safety, and reliability, as well as to minimize the cost of quality. The purpose of this paper is to present a methodology that can be used by corporations to ensure a product's reliability, safety, and maintainability, with minimal costs, by measuring dependability levels and conducting DEA analysis. The methodology will be a way for corporations to adopt an optimal dependability management system based on a quality management system of ISO 9001:2000 standards.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.191-197
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• 2009

As a case study on determining the replacement interval for the CMB contactor, we analyzed a field failure data during 59 months and through the simulation reliability is analyzed. As a result of analyzing the reliability we estimated parameters and analyzed distribution characteristics. Ultimately using the estimated results and applying the Age Replacement Policy considered the cost information, CMB contactor's replacement interval is determined. Through the comparison, analysis between the replacement interval and manufacturing company's, the necessity of replacement interval that is reflected in our operation circumstances is examined.

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.207-221
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• 2006

Corporations are faced with the key strategic task of adopting a comprehensive management system of a new paradigm in order to enhance their products' quality, safety, and reliability, as well as to minimize the cost of quality. The purpose of this paper is to present a methodology that can be used by corporations to ensure a product's reliability, safety, and maintainability, with minimal costs, by measuring dependability levels and conducting DEA analysis. The methodology will be a way for corporations to adopt an optimal dependability management system based on a quality management system of ISO 9001:2000 standards.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.4
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• pp.154-160
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• 2003

The switched reluctance motor(SRM) has a considerable potential for industrial applications because of its high reliability as a result of the absence of rotor windings. In some applications with SRM, a parallel switching strategy is often used for cost saving, increasing of current capacity and system reliability. This paper proposes a new parallel switching strategy of SRM using parallel winding. While conventional parallel switching devices are connected in a phase winding, power devices are connected in the parallel windings wound in each pole of stator in the proposed method. Paralleling strategy for current sharing in the proposed method can be easily determined without considerations of any nonlinear characteristics of power devices such as conduction resistance, threshold voltage and gain factor. The proposed paralleling strategy is verified by the mathematical analysis and experimental results.

• International Journal of Reliability and Applications
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• v.18 no.2
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• pp.45-63
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• 2017

In this paper, we have formulated optimum Accelerated Life Test (ALT) plan for a parallel system with two independent components using masked data with ramp-stress loading scheme and Type-I censoring. Consider a system of two independent and non-identical components connected in parallel. Such a system fails whenever all of its components has failed. The exact component that causes the system to fail is often unknown due to cost and time constraint. For each parallel system at test, we observe its system's failure time and a set of component that includes the component actually causing the system to fail. The stress-life relationship is modelled using inverse power law, and cumulative exposure model is assumed to model the effect of changing stress. The optimal plan consists in finding out the optimum stress rate using D-optimality criterion. The method developed has been explained using a numerical example and sensitivity analysis carried out.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.4
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• pp.154-154
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• 2003

The switched reluctance motor(SRM) has a considerable potential for industrial applications because of its high reliability as a result of the absence of rotor windings. In some applications with SRM, a parallel switching strategy is often used for cost saving, increasing of current capacity and system reliability. This paper proposes a new parallel switching strategy of SRM using parallel winding. While conventional parallel switching devices are connected in a phase winding, power devices are connected in the parallel windings wound in each pole of stator in the proposed method. Paralleling strategy for current sharing in the proposed method can be easily determined without considerations of any nonlinear characteristics of power devices such as conduction resistance, threshold voltage and gain factor. The proposed paralleling strategy is verified by the mathematical analysis and experimental results.