• International Journal of Reliability and Applications
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• v.3 no.4
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• pp.173-184
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• 2002

This paper introduces the joint structural importance of two components in a coherent system. Some relationships between joint structural importance and marginal structural importance are presented. It is shown that the sign of Joint structural importance can be determined, in advance, without computation in some special structures. The joint structural importance of two components in some series-parallel and parallel-series systems are established. Some practical examples are presented to elucidate some of the derived results.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.2
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• pp.229-237
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• 1995

The purpose of this study is to define requisite content of physiology for nursing education. This study classifies the subjects of physiology into 15 areas. The areas are cell and cell membrane, body fluid, nervous system, special sense, muscular system, blood, cardiovascular system, respiratory system, urinary system, digestive system, energy metabolism, body temperature, immune system, endocrine system, and reproductive system. Each subject area is further classified into subarea, resulting in a total of 194 subarea. The importance of each subarea is measured with a 3-point scale using a questionnaire. The subjects of this study were full-time professors teaching nursing in Korean universities. The analysis of the data collected from 68 respondents is as follows. 1. The areas of physiology necessary for nursing education in the order of importance are : body fluid, blood, endocrine, immune system, body temperature, urinary system, respiratory system, digestive system, reproductive system, energy metabolism, nervous system, cardiovascular system, cell and cell membrane, muscular system, and special sense. 2. Depending on the specific areas of nursing(such as pediatric nursing, maternity nursing), the importance of each physiology area may differ. For instance, the most important area for maternity nursing is reproductive physiology, whereas one for the psychiatric nursing is neuro-physiology. 3. The importance of each physiology area does not determine the importance of its subarea. For example, while the importance of cell and cell membrane was relatively very low across the respondents from different areas of nursing science, the importance of such subarea as osmosis, diffusion, and filteration reported by most respondents were high.

• International Journal of Reliability and Applications
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• v.12 no.2
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• pp.103-116
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• 2011

A series-parallel system with independent but non-identical components is considered. The expressions have been derived for the joint reliability importance (JRI) of m (${\geq}2$) components, chosen from a series-parallel system. JRIs of components of two different series-parallel systems are studied analytically and graphically.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.04a
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• pp.34-42
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• 1991

This study is directed for the development of an efficient system-level Importance Sampling Technique for system reliability analysis of bridge structures Many methods have been proposed for structural reliability assessment purposes, such as the First-order Second-Moment Method, the Advanced Second-Moment Method, Computer Simulation, etc. The Importance Sampling Technique can be employed to obtain accurate estimates of the required probability with reasonable computation effort. Based on the observation and the results of application, it nay be concluded that Importance Sampling Method is a very effective tool for the system reliability analysis.

• Journal of the Korea Safety Management & Science
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• v.2 no.4
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• pp.91-102
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• 2000

Nowadays, every kind of system is changed so complex and enormous, it is necessary to assure system reliability, product liability and safety. Fault tree analysis(FTA) is a reliability/safety design analysis technique which starts from consideration of system failure effect, referred to as “top event”, and proceeds by determining how these can be caused by single or combined lower level failures or events. So in fault tree analysis, it is important to find the combination of events which affect system failure. Minimal cut sets(MCS) and minimal path sets(MPS) are used in this process. FTA-I computer program is developed which calculates MCS and MPS in terms of Gw-Basic computer language considering Fussell's algorithm. FTA-II computer program which analyzes importance and function cost of VE consists. of five programs as follows : (l) Structural importance of basic event, (2) Structural probability importance of basic event, (3) Structural criticality importance of basic event, (4) Cost-Failure importance of basic event, (5) VE function cost analysis for importance of basic event. In this study, a method of initiation such as failure, function and cost in FTA is suggested, and especially the priority rank which is calculated by computer-aided decision analysis program developed in this study can be used in decision making determining the most important basic event under various conditions. Also the priority rank can be available for the case which selects system component in FMEA analysis.

• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.225-233
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• 2012

The research discusses interrelationship of structural and reliability importance measures which used in the probabilistic safety assessment. The most frequently used component importance measures, such as Birnbaum's Importance (BI), Risk Reduction (RR), Risk Reduction Worth (RRW), RA (Risk Achievement), Risk Achievement Worth (RAW), Fussel Vesely (FV) and Critically Importance (CI) can be derived from two structure importance measures that are developed based on the size and the number of Minimal Path Set (MPS) and Minimal Cut Set (MCS). In order to show an effectiveness of importance measures which is developed in this paper, the three representative functional structures, such as series-parallel, k out of n and bridge are used to compare with Birnbaum's Importance measure. In addition, the study presents the implementation examples of Total Productive Maintenance (TPM) metrics and alternating renewal process models with exponential distribution to calculate the availability and unavailability of component facility for improving system performances. System state structure functions in terms of component states can be converted into the system availability (unavailability) functions by substituting the component reliabilities (unavailabilities) for the component states. The applicable examples are presented in order to help the understanding of practitioners.

• Communications for Statistical Applications and Methods
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• v.14 no.3
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• pp.577-582
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• 2007

A continuum structure function (CSF) is a non-decreasing mapping from the unit hypercube to the unit interval. A B-type CSF, defined in the text, is a CSF whose behaviour is modeled by its underlying binary structures. As the measure of importance of a system component for a B-type CSF, the structural and reliability importance of a component at a system level ${\alpha}$(0 < ${\alpha}$ < 1) are defined and their properties are deduced.

• The Journal of Information Systems
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• v.31 no.1
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• pp.239-269
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• 2022

Purpose This paper attempts to identify items for improving the usage of PLM(Product Lifecycle Management) systems and suggests ways to prioritize improvement items on the basis of importance. It also tries to find out differences in the importance of improvement items due to the company size, the industry, the job, or the PLM solution. Design/methodology/approach Through a survey from participants to a PLM System Conference, data were collected from a sample of 181 users who had the previous experience in using a PLM system. In order to figure out the differences in the importance among user groups, the F-test with the Scheffe test as a post-hoc analysis was used in case of equal variances and the Welch test with the Dunnett T3 test was used in case of unequal variances. Findings This study sorted out 25 improvement ideas according to their importance assessed by the PLM system users. The top five ideas are improving data consistency, error minimization, fast system response time, enhancing user recognition, and business process improvement. The support group puts higher importance than the general user group in data consistency, fast system response time, enhancing user recognition, business process improvement, dedicated team for data consistency, continuous support from management, hardware performance upgrade, output linkage to other systems, and shortening problem solving duration. The largest company group attaches significantly higher weights than the smallest company group to data consistency, error minimization, fast system response time, business process improvement, dedicated team for data consistency, security with proper access management, output linkage to other systems, and better user interface.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.41-50
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• 2017

The purpose of this paper is to improve the service tree analysis introduced recently by Geum et al. [15]. Service tree analysis structures the service based on the customer participation perspective and provides a qualitative analysis method categorizing the service elements on the basis of its impact to top service. This paper attempts to apply the concept of reliability importance to the service tree analysis as a perspective of quantitative analysis, which is considered little in Geum et al. [15]. Reliability importance is a measure of the structural impact of the components that make up the system on the system lifetime in reliability engineering field and often used in fault tree analysis. We transform the reliability importance into service importance in accordance with service tree analysis, so that the influence of service elements on the service can be judged and compared. The service importance is defined as the amount of change of the service according to the change of the service element, therefore, it can be utilized as an index for determining a service element for service improvement. In addition, as an index for paired service elements, the relationship between the two service components can be measured by joint service importance. This paper introduces conceptual changes in the process of applying reliability importance to service analysis, and shows how to use the service importance for identifying the priority of service element for the final service and improving customer satisfaction through an example. By using the service importance and joint service importance in service tree analysis, it is possible to make efficient decision making in the process of determining the service elements for analyzing and improving the service.

• Korean Journal of Community Nutrition
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• v.9 no.2
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• pp.233-240
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• 2004

This study was design to grope the suggestions leading synergic effects by bridging the gap between headquarters and branch office, and so to identify the infra-system of contract foodservice management company (CFMC) necessary for operating any kind of branch office including school, hospital and business and industry (B＆I). Among 8 categories consisted of infra-system in CFMC, 'C8. Evaluation ＆ analysis for branch office's operation' was the most important category in the headquarter's viewpoint, while 'C3. Sanitation management system' was the most important category in branch office's viewpoint. In support and application, 'C3. Sanitation management system' was the highest category in both headquarters and branch offices including school, hospital and B＆I. As a result of analysis on gap between main and branch office in importance, support and application in 8 categories, the efforts of communication and community of perception for infrastructure were needed, because 'C4. Education ＆ training for human resource management (HRM) system' and 'C8. Evaluation ＆ analysis for branch office's operation' in importance, 'C2. Menu management system', 'C4. Education ＆ training for HRM system', 'C6. Facility ＆ utility support system' and 'C8. Evaluation ＆ analysis for branch office's operation' in support had a gap. Correlation analysis to grasp the relation between importance of infra-system and headquarters' support or branch office's application showed that headquarters's importance and support were correlated positively in 'C3. Sanitation management system', 'C6. Facility ＆ utility support system', 'C7. Customer satisfaction management system' and 'C8. Evaluation ＆ analysis for branch office's operation' and branch office's importance and application were correlated positively in 'C1. Procurement ＆ food processing system', 'C5. Management Information system', 'C7. Customer satisfaction management system' and 'C8. Evaluation ＆ analysis for branch office's operation'. Lastly, 'C6. Facility ＆ utility support system' in the branch office of school and hospital and 'C2. Menu management system' in the branch office of B＆I were high in importance, low in support and application, therefore Intensive support for these categories was needed. In conclusion, continuous check and improvement for categories, which were identified as an urgent problems to be solved in this study, among infra-structure qualifying for CFMC, would enable contract foodservice industry that has grown quantitatively till now to grow qualitatively.