• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.759-767
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• 2009

Recently, there is a trend to introduce a reliability approach to the design of al large scale improvement of weak ground due to the uncertainty of the influence factors in the consolidation. Since the reliability analysis is not easily adopted to geotechnical engineers because of some difficulties in working up the theories, Duncan(2000) proposed a simplified method for using reliability method to goetechnical problems. In this study, the applicability of Duncan's simplified reliability approach is evaluated by comparing the traditional reliability results with Duncan's. In the sensitivity analysis, the two results were quite similar. However, the probability of failure showed an error range of 20~50% and further Duncan's approach could not make a distinction for the distribution of geotechnical random variables. The simplified reliability method seems to be used properly in preliminary design if it is used supplementary with the deterministic method.

• Journal of Ship and Ocean Technology
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• v.4 no.2
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• pp.38-57
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• 2000

This paper deals with reliability analysis of specially orthotropic plates subjected to transverse lateral pressure loads by using Monte Carlo simulation method. The plates are simply supported around their all edges and have a low short span to plate depth ratio with rectangular plate shapes. Various levels of reliability analyses of the plates are performed within the context of First-Ply-Failure(FPF) analysis such as ply-/laminate-level reliability analyse, failure tree analysis and sensitivity analysis of basic design variables to estimated plate reliabilities. In performing all these levels of reliability analyses, the followings are considered within the Monte Carlo simulation method: (1) input parameters to the strengths of the plates such as applied transverse lateral pressure loads, elastic moduli, geometric including plate thickness and ultimate strength values of the plates are treated as basic design variables following a normal probability distribution; (2) the mechanical responses of the plates are calculated by using simplified higher-order shear deformation theory which can predict the mechanical responses of thick laminated plates accurately; and (3) the limit state equations are derived from polynomial failure criteria for composite materials such as maximum stress, maximum strain, Tsai-Hill, Tsai-Wu and Hoffman.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.2
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• pp.74-82
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• 1998

To evaluate the reliability against fatigue failure of offshore structures, a fatigue reliability analysis model based on the probabilistic approach has been developed. In this model, the simplified method is adopted as a fatigue analysis method. The uncertainties included in the fatigue analysis are considered as random variables and their statistical properties are evaluated as quantitatively as possible using existing data. As an example, the developed fatigue reliability model is applied to the jacket. And then the relative significance of each uncertainty on the probability of fatigue failure is surveyed.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.244-255
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• 1998

The purpose of this study was to verify the reliability and validity of the Rosenbaum self-control schedule (SCS) for assessing resourcefulness in Korea and to explore the simplified scale. The study subjects consisted of 787 adults in a community. The data was collected during the period from Oct. to Dec., 1995 and analyzed as Cronbach α, item correlation with total, Pearson correlation and factor analysis with varimax rotation using SAS. Results were as follows : The mean SCS score for this sample was 17.2 and there were statistical differences for gender(men, 13.1 ; women, 20.0) on the SCS scores. The cronbachα of SCS with 36 items was .74 and when simplified with 30 items, it's coefficient alpha was .78. The translated content of the SCS was validated by two nursing faculty members and one professor of psychology. Factor analysis revealed the most parsimonious structure was obtained when six factors were extracted and subsequently rotated via the varimax criterion. There was 40.2% of total communality variance in the SCS with 36 items. The total communality variance was slightly increased to 43.4% with 30 items of the SCS. In order to reduce from 36 items to 30 items, the process excepted 6 items having low item correlation with total and low MSA(means of sampling adequacy) of factor analysis. According to factor analysis, there are six factors such as emotion control, impulse control, self-efficacy, coping with problems, pain control and satisfaction control, The SCS was found to have low, but statistically significant, correlations with social desirability and helplessness. From the above results, it can be concluded that the reliability of the SCS(inherent and simplified) was a acceptable level and its validity was reasonable when comparing it with other validity studies. To determine the usefulness the simplified scale, further study is necessary to simultaneously compare and analyze both scales for stability.

• Communications for Statistical Applications and Methods
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• v.3 no.3
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• pp.125-133
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• 1996

In this paper, we present a algebraic technique for computing system reliability for complex system. The method was originally developed as an aid to fault tree analysis but it applies to general problems of reliability assessment. A success expression which directly gives the reliability expression is formed and simplified by the procedure. Several algorithms and examples are illustrated.

• Structural Engineering and Mechanics
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• v.62 no.3
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• pp.365-372
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• 2017

Reliability analysis is a probabilistic approach to determine a safety level of a system. Reliability is defined as a probability of a system (or a structure, in structural engineering) to functionally perform under given conditions. In the 1960s, Basler defined the reliability index as a measure to elucidate the safety level of the system, which until today is a commonly used parameter. However, the reliability index has been formulated based on the pivotal assumption which assumed that the considered limit state function is normally distributed. Nevertheless, it is not guaranteed that the limit state function of systems follow as normal distributions; therefore, there is a need to define a new reliability index for no-normal distributions. The main contribution of this paper is to define a sophisticated reliability index for limit state functions which their distributions are non-normal. To do so, the new definition of reliability index is introduced for non-normal limit state functions according to the probability functions which are calculated based on the convolution theory. Eventually, as the state of the art, this paper introduces a simplified method to calculate the reliability index for non-normal distributions. The simplified method is developed to generate non-normal limit state in terms of normal distributions using series of Gaussian functions.

• Journal of Korean society of Dental Hygiene
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• v.21 no.2
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• pp.171-182
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• 2021

Objectives: Recently, subjective career success has been used as a criterion for evaluating career success. The purpose of this study was to develop and evaluate a simplified subjective career success inventory for dental hygienists. Methods: Subfactors of the subjective career success inventory consisted of career satisfaction, employability, and job satisfaction. The validity and reliability of the existing tools were evaluated through the basic items composition, content validity index (CVI), preliminary survey, and main survey process according to dental hygienists. The preliminary survey was composed of 35 questions by verifying the content validity twice from the existing 63 questions, and the main survey was conducted with a total of 12 questions. Samples were conveniently extracted from dental hygienists with a clinical career of ≥3 years and surveyed online from March 12, 2020 to June 30, 2020. Data of 320 people were collected, of which 284 were finally analyzed. The validity and reliability were analyzed using SPSS 18.0 and AMOS 18.0 (p<0.05). Results: The subjective career success was a shortened inventory composed of nine questions, and the overall reliability was Cronbach's α=0.841. Using exploratory factor analysis, three factors were extracted. As a result of the confirmatory factor analysis, each measurement variable significantly explained the latent factor, and the fit of the model was appropriate. The fit of the model was appropriate for the structural equation model. Among the sub-factors of subjective career success, career satisfaction and job satisfaction had a significant effect on intention to stay (p<0.05). Conclusions: The simplified subjective career success inventory developed for dental hygienists was found was found to be a useful tool in terms of reliability and validity.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.3
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• pp.51-56
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• 2012

The wing is a framework composed chiefly of skin, spars, ribs and can be simplified by matrix structure. In this paper, a displacement reliability of matrix structure is analysed by AFORM(Advanced First Order Reliability Method) and applicability is assessed.

• Wind and Structures
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• v.12 no.2
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• pp.121-132
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• 2009

A systematic reliability evaluation approach for torsional divergence analysis of long span suspension bridges is proposed, consisting of the first order reliability method and a simplified torsional divergence analysis method. The proposed method was implemented in the deterministic torsional divergence analysis program SIMTDB through a new strategy involving interfacing the proposed method with SIMTDB via a freely available MATLAB software tool (FERUM). A numerical example involving a detailed computational model of a long span suspension bridge with a main span of 888 m is presented to demonstrate the applicability and merits of the proposed method and the associated software strategy. Finally, the most influential random variables on the reliability of long span suspension bridges against torsional divergence failure are identified by a sensitivity analysis.

• Structural Engineering and Mechanics
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• v.28 no.1
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• pp.1-18
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• 2008

The conventional design of bridge piers against scour uses scour equations which involve number of uncertain flow, sediments and structural parameters. The inherent high uncertainties in these parameters suggest that the reliability of piers must be assessed to ensure desirable safety of bridges against scour. In the present study, a procedure for the reliability assessment of bridge piers, installed in main and flood channels, against scour has been presented. To study the influence of various random variables on piers' reliability sensitivity analysis has been carried out. To incorporate the reliability in the evaluation of safety factor, a simplified relationship between safety factor and reliability index has been proposed. Effects of clear water (flood channel) and live bed scour (main channel) are highlighted on pier reliability. In addition to these, an attempt has also been made to explain the failure of Black mount bridge of New Zealand based on its pier's reliability analysis. Some parametric studies have also been included to obtain the results of practical interest.