• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.93-101
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• 2015

The demand from customers on better products and systems seems to be ever increasing. To meet the demand, the systems are becoming more and more complicated in terms of both scale and functionality, thereby requiring enormous effort in the development. One bright spot of this trend is that such effort has been the driving forces of the remarkable advancement in modern systems development. On the other hand, safety issues appear to be critical in many large-scale systems such as transportation and weapon systems including high-speed trains, airplanes, ships, missiles/rockets launchers, and so on. Such systems turn out to be prone to a variety of faults and thus the resultant failure can cause disastrous accidents. For the reason, they can be referred to as safety-critical systems. The systems failure can be attributed to either random or systemic factors (or sometimes both). The objective of this paper is on how to reduce potential systemic failure in safety critical systems. To do so, a proper system design is pursued to minimize the risk of systemic failure. A focus is placed on the fact that complex systems have a lot of complicated interfaces among the system elements. To effectively handle the sources of hazards at the complicated interfaces and resultant failure, a method is developed by utilizing a design structure matrix. As a case study, the developed method is applied in the design of train control systems.

• Journal of Korean Society for Quality Management
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• v.33 no.4
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• pp.75-87
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• 2005

Generally speaking, weapon system is defined as a combination of primary system and support system which are evaluated by capability and operational availability respectively. Recently comparison of total life cycle cost shows that logistic support system is proved to be more important than primary system. However, until now systematic approach to support system development has not been applied in the area of developing support system. We need to construct a universal metric for effectiveness of logistic support system and to cut out whatever activities or support elements which do not contribute to the metric. This paper describes a new approach based on system engineering approach to logistic support system and also classifies five factors of failure, stock-out frequency, administrative delay time, active repair time and logistic delay time that have influence on operational availability of logistic support system.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.742-747
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• 2008

This paper is described the systematic activities of RCM to improve the availability for AREX railway system. The purpose of these activities are to maintain and enhance the reliability, availability, maintainability and safety, and to implement the effective maintenance for electrical and mechanical system including rolling stock, signalling, telecommunication, power supply, overhead catenary and platform screen door with impact to train operation.. The main activities consist of systematic failure and repair recording by integral information system, analysis and corresponding countermeasure. As applying these activities in opeartion and maintenance works, the availability of AREX railway system is going on improvement gradually, and maintenacne works are improved with these results.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.75-87
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• 2015

Background: Lumbar discogenic pain without pain mediated by a disc herniation, facet joints, or the sacroiliac joints, is common and often results in chronic, persistent pain and disability. After conservative treatment failure, injection therapy, such as an epidural injection, is frequently the next step considered in managing discogenic pain. The objective of this systematic review is to determine the efficacy of lumbar epidural injections in managing discogenic pain without radiculopathy, and compare this approach to lumbar fusion or disc arthroplasty surgery. Methods: A systematic review of randomized trials published from 1966 through October 2014 of all types of epidural injections and lumbar fusion or disc arthroplasty in managing lumbar discogenic pain was performed with methodological quality assessment and grading of evidence. The level of evidence was based on the grading of evidence criteria which, was conducted using 5 levels of evidence ranging from levels I to V. Results: Based on a qualitative assessment of the evidence for both approaches, there is Level II evidence for epidural injections, either caudal or lumbar interlaminar. Conclusions: The available evidence suggests fluoroscopically directed epidural injections provide long-term improvement in back and lower extremity pain for patients with lumbar discogenic pain. There is also limited evidence showing the potential effectiveness of surgical interventions compared to nonsurgical treatments.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.24-31
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• 1997

Recently, in Korea, demand for establishment of systematic risk assessment techniques for construction projects has increased, especially after the large construction failures occurred during construction such as New Haengju Bridge construction projects, subway construction projects, gas explosion accidents etc. Most of existing risk analysis modeling techniques such as Event Tree Analysis and Fault Tree Analysis may not be available for realistic risk assessment of construction projects because it is very complex and difficult to estimate occurrence frequency and failure probability precisely due to a lack of data related to the various risks inherent in construction projects like natural disasters, financial and economic risks, political risks, environmental risks as well as design and construction-related risks. Therefor the main objective of this paper is to suggest systematic probabilistic risk assessment model and demonstrate an approach for probabilistic risk assessment using advanced Event Tree Analysis introducing Fuzzy set theory concepts. It may be stated that the Fuzzy Event Tree AnaIysis may be very usefu1 for the systematic and rational risk assessment for real constructions problems because the approach is able to effectively deal with all the related construction risks in terms of the linguistic variables that incorporate systematically expert's experiences and subjective judgement.

• Clinics in Shoulder and Elbow
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• v.26 no.3
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• pp.312-322
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• 2023

Background: Silicone radial head prostheses (SRHP) are considered obsolete due to reports of frequent failure and destructive silicone-induced synovitis. Considering the good outcomes of modern non-radial silicone joint implants, the extent of scientific evidence for this negative view is unclear. The aim of this research was to systematically analyze the clinical evidence on complications and outcomes of SRHP and how SRHP compare to both non-SRHP and silicone prostheses of other joints. Methods: A systematic literature review was conducted through the Cochrane, PubMed, and Embase databases. Results: Eight cohort studies were included, consisting of 142 patients and follow-up periods ranging from 23 months to 8 years. Average patient satisfaction was 86%, range of 71%-100%, and 58 complications were seen, but no cases of synovitis. These outcomes were in line with non-SRHP. Four case series with 11 cases of synovitis were found, all due to implant fractures years to decades after implantation. Six systematic reviews of currently used non-radial silicone joint implants showed excellent outcomes with low complication rates. Conclusions: Since SRHP have satisfactory clinical results and an acceptable complication rate when selecting a patient group in suitable condition for surgical indications, it is considered that SRHP can still be chosen as a potential surgical treatment method in current clinical practice.

• Journal of Korean Biological Nursing Science
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• v.12 no.2
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• pp.114-126
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• 2010

Purpose: To examine the levels of the disease-related knowledge and educational demands of pre-dialysis, chronic renal failure patients at different GFRs and stages. Methods: This study used a cross-sectional survey and aimed at 116 pre-dialysis, chronic renal failure patients, who were registered and received regular treatment from December 1 to December 31, 2009 at the nephrology departments of tertiary medical centers in Seoul. Stages were classified into Stage 3, 4 and 5 depending on GFR ranges. To measure the levels of knowledge and educational demands, the tool, which were first invented by Young Ae Lim (1996) and then modified by Hyo Sun Lim (2005) to adjust the knowledge and educational demands measuring tool for hemodialysis patients to pre-dialysis patients with chronic renal failure, was used. Collected data was analyzed with the SPSS WIN 12.0 program (average, standard deviation, Pearson's correlation coefficient, t-test and ANOVA). Results: There was a significant difference in the disease-related knowledge levels of the subjects at each stage (F=24.41, p=.000). The Scheffe post hoc test confirmed that patients at higher stages had higher levels of knowledge of their disease. Also, although the results showed that patients at higher stages had higher educational demands, there was no significant difference among the groups (F=1.259, p=.288). Conclusion: As patients have different levels of knowledge of the disease and educational demands depending on their stages, it is important to develop and use a systematic education program that reflects the demands and levels of patients at each stage in order to help pre-dialysis patients with chronic renal failure with self-management and improve their quality of life.

• Korean Management Science Review
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• v.11 no.2
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• pp.1-27
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• 1994

A reliability data processing MPRDP (Multi-Purpose Reliability Data Processor) has been developed in FORTRAN language since Jan. 1992 at KAERI (Korean Atomic Energy Research Institute). The purpose of the research is to construct a reliability database(plant-specific as well as generic) by processing various kinds of reliability data in most objective and systematic fashion. To account for generic estimates in various compendia as well as generic plants' operating experience, we developed a 'three-stage' Bayesian procedure[1] by logically combining the 'two-stage' procedure[2] and the idea for processing generic estimates[3]. The first stage manipulates generic plant data to determine a set of estimates for generic parameters,e.g. the mean and the error factor, which accordingly defines a generic failure rate distribution. Then the second stage combines these estimates with the other ones proposed by various generic compendia (we call these generic book type data). This stage adopts another Bayesian procedure to determine the final generic failure rate distribution which is to be used as a priori distribution in the third stage. Then the third stage updates the generic distribution by plant-specific data resulting in a posterior failure rate distribution. Both running failure and demand failure data can be handled in this code. In accordance with the growing needs for a consistent and well-structured reliability database, we constructed a generic reliability database by the MPRDP code[4]. About 30 generic data sources were reviewed and available data were collected and screened from them. We processed reliability data for about 100 safety related components frequently modeled in PSA. The underlying distribution for the failure rate was assumed to be lognormal or gamma, according to the PSA convention. The dependencies among the generic sources were not considered at this time. This problem will be approached in further study.

• The Research Journal of the Costume Culture
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• v.18 no.3
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• pp.526-540
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• 2010

Due to fierce competition, many domestic fashion businesses are suffering difficulty in securing and maintaining customers. Accordingly, fashion companies are devoting all their energy to secure customers by using high quality and diverse strategies for distribution and promotion, and to secure loyalty by satisfying customers with the offer of excellent service. Thus, it is very important to provide systematic service recovery strategy available for handling service failure effectively. Therefore, the purpose of this study is comprehensively analyzing influences of expectation dis-confirmation and perceived justice for service recovery upon consumers' satisfaction and loyalty. The findings are as follows. First, as for the service failure that customers experienced, the more consumers who expect it to be recovered led to the higher formation of expectation-compensation dis-confirmation. Second, it was indicated that the higher seriousness in service failure that customers experienced led to the lower satisfaction and loyalty to service recovery. Third, as a result of examining influence of expectation-compensation dis-confirmation for service-failure recovery upon consumer satisfaction and loyalty, the customers who showed more positive dis-confirmation to expectation-compensation were indicated to form the more satisfaction and loyalty. Fourth, as a result of examining the influence of the perceived justice in the process of service-failure recovery upon customer satisfaction, all in 3 dimensions of justice had effect on customer satisfaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.385-397
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• 2021

This study examined service failure and recovery of domestic ethnic food restaurants based on a model of the repercussions of service failure dealing with seriousness and control and the cause-and-effect relationships among the variables relevant to the quality of relationships -trust, satisfaction, and loyalty. This study provides valuable information for Korean restaurant managers regarding food service failure and response plans by collecting data from actual Japanese tourists visiting ethnic food restaurants. The results suggested that it is important to develop a strategy to present the distributional fairness to customers who recognize the seriousness of service failure to control the situation promptly. These results can be used to establish more systematic business plans, improving customer management and firm performance. The advantage of this research is that it is time for substantial research data on the booming domestic restaurant industry and service quality to overcome the current recession and grow and solidify the current restaurant market.