• 아동학회지
• /
• 제29권3호
• /
• pp.303-318
• /
• 2008

Participants in this study of the validity and reliability of PIPPS (Penn Interactive Peer Play Scale; Fantuzzo et al., 1998) for Korean children were 248 5-to 6-year - old children and 11 teachers. Instruments included the Peer Rating Scale(PRS; Singleton et al., 1979), Social Competence and Behavior Evaluation (SCBE; LaFreniere & Dumas, 1995), and Preschool Behavior Questionnaire (PBQ; Behar & Stringfield, 1974). The structure of PIPPS resulted in 3 factors, 'play disruption', 'play interaction', and 'play disconnection' with 30 items similar to the original PIPPS factors. Validity was evidenced by inter-correlations among sub-factors and by correlations between PIPPS and criterion measures. PIPPS scores were validated by ratings from PRS, SCBE and PBQ sub-areas scores. Cronbach's a reliability of PIPPS factors ranged from .88 to .92.

• 한국신뢰성학회:학술대회논문집
• /
• 한국신뢰성학회 2000년도 추계학술대회
• /
• pp.405-409
• /
• 2000

The flow network is considered to be in a functioning state if it can transmit a maximum flow which is greater than or equal to a specified amount of flow. In this paper we consider the measures of importance of a link in the flow network. We define the structural importance and reliability importance of link when the required amount of flow is given. Also, we present the performance importance of link in a flow network. The performance importance can be used to determine which links should be improved first in order to make the greatest improvement in performance of the network. Numerical examples are presented for illustrative purpose.

• 산업경영시스템학회지
• /
• 제17권32호
• /
• pp.227-232
• /
• 1994

In the performance domain, physical performance is a measure that represents some degree of system, subsystem, component or device success in a continuous sense, as opposed to a classical binomial sense (success or failure). If applicable sensing and monitoring means exist, physical performance can be observed over time, along with explanatory variables or covariables. Performance-based reliability represents the probability that performance will remain satisfactory over a finite period of time or usage cycles in the future when a performance critical limit (which represents an appropriate definition of failure in terms of performance) is set at a fixed level, based on application requirements. In the case of inadequate knowledge of the failure mechanics, this physical based empirical modeling concept along with performance degradation knowledge can serve as an important analysis tool in reliability work in product and process improvement.

• International Journal of Reliability and Applications
• /
• 제3권3호
• /
• pp.133-145
• /
• 2002

The traditional methods of evaluating the performance of a network by enumerating all possible states may quickly become computationally prohibitive, since the number of states grows exponentially as the number of components increases. In such cases, enumerating only the most probable states would provide a good approximation. In this paper, we propose a method which efficiently generates upper and lower bounds for coherent performance measures utilizing the most probable states. Compared with Yang and Kubat's method, our procedure significantly reduces the complexity and memory requirement per iteration for computing the bounds and thereby, achieves the given degree of accuracy or the coverage within a shorter time.

• International Journal of Reliability and Applications
• /
• 제15권1호
• /
• pp.51-64
• /
• 2014

This paper develops a warranty cost model for complex systems with imperfect repair within a warranty period by addressing a practical case that the first inter-failure interval is longer than any other inter-failure intervals. The product is in its best condition before the first failure if repair is imperfect. After the imperfect repair, other inter-failure intervals which are explained by renewal processes, are stochastically smaller than the first inter-failure interval. Based on this idea, we suggest the failure-interval-failure-criterion model. In this model, we consider two random variables, X and Y where X represents failure intervals and Y represents failure criterion. We also obtain the distribution of the number of failures and conduct the warranty cost analysis. We investigate different types of warranty cost models, reliabilities and other measures for various systems including series-parallel configurations. Several numerical examples are discussed to demonstrate the applicability of the methodologies derived in the paper.

• Industrial Engineering and Management Systems
• /
• 제9권1호
• /
• pp.20-27
• /
• 2010

The purpose of this study was to compare the consistency of external ear measurements obtained by electronic digital caliper, photocopier scanning and digital photographic methods. Photogrammetric measurements were made after image editing software was used to optimize the brightness, contrast, size and image clarity. The CorelDRAW dimension tool was used to create a dimension line that measured the vertical and horizontal length between any two landmarks. Results of repeated measures analysis of variance revealed no significant differences in length and width of the pinna between the three methods. The reliability of the three measurement techniques showed a high degree of consistency. Further study and efforts could be extended to measurement hands, foots and facial dimensions by present techniques.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제3권1호
• /
• pp.1-12
• /
• 2003

A continuum structure function(CSF) is a non-decreasing mapping from the unit hypercube to the unit interval. A Barlow-Wu type CSF is a CSF whose behaviour is modeled by its underlying binary structure, which is based on the multistate structure functions suggested by Barlow and Wu(1978). As the measures of importance of a system component for a Barlow-Wu type CSF, the structural and reliability importance of a component at system level ${\alpha}$ (0< ${\alpha}$ <1) are defined and their properties are deduced. Computational results are discussed as well for illustrative purpose.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제17권2호
• /
• pp.150-158
• /
• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• 산업경영시스템학회지
• /
• 제18권36호
• /
• pp.371-377
• /
• 1995

Modern combat (or commertial) aircraft systems consist of a large number of sophisticated and complex avionics/electronics subsystems. The US Air Force of Productivity, Reliability, Availability and Maintainability (PRAM) reports that 25 to 45 percent of aircraft system failures in the electronics or electromechanical area 〔Kachmar, 1985〕. It is an important issue to achive the required reliability and maintainability for avionics/electronics subsystems in order to guarantee the mission success during the life cycle in a timely and cost effective manner. The issuance of USAF Mil-A-87244, "Avionics/Electronic Integrity Program requirements," 1987 demands a new approach called "Avionics/Electronics Integrity Program" (AVIP). The objective of this paper is to give a tutorial presentation on the basic aspects of Avionics/Electronics Integrity efforts in relation to total quality management of avionics/electronics whose performance measures are expressed in terms of reliability, durability, and matainability.

• Journal of applied mathematics & informatics
• /
• 제41권6호
• /
• pp.1275-1301
• /
• 2023

This paper introduced the Weibull Marshall-Olkin Power Lomax (WMOPL) distribution. The statistical aspects of the proposed model are presented, such as the quantiles function, moments, mean residual life and mean deviations, variance, skewness, kurtosis, and reliability measures like the residual life function, and stress-strength reliability. The parameters of the new model are estimated using six different methods, and simulation research is illustrated to compare the six estimation methods. In the end, two real data sets show that the Weibull Marshall-Olkin Power Lomax distribution is flexible and suitable for modeling data.