• Title/Summary/Keyword: Reliability analyses

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Instrument Development for Patient Respect (환자 존중 측정도구 개발)

  • Yoo, Myoung-Ran;Hyeon, Jin-Suk;Choi, Yun-Jung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.13 no.2
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    • pp.162-168
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    • 2007
  • Purpose: Patients hope to receive 'respected nursing' which guarantees the right of privacy and treatment as a human being in hospitals. However, no specific tool has been developed to measure patients' perceived respect from nurses while staying in hospitals. This study was conducted to develop a tool to measure the respect that they experience in hospital. Method: A basic questionnaire was made based on research literature, pilot studies, and collected data via patients' interviews. The questionnaire was verified by 5 members of an expert group, a chief nurse in the clinical area and 10 patients. We distributed the questionnaires to 266 randomly selected inpatients and carried out analyses of factors and content to evaluate the validity and reliability of the questionnaire. Result: According to the results of factor analyses, three factors such as 'cordial treatment', 'consideration', and 'recognition' were extracted, which took up to 61 percent from all variants. Final questionnaires has 30 questions on a 4-point scale. Conclusion: The questionnaire which was designed through the study showed a high reliability and validity. We anticipate that this questionnaire will contribute to fostering nursing care with respect for patients.

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More reliable responses for time integration analyses

  • Soroushian, A.;Farjoodi, J.
    • Structural Engineering and Mechanics
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    • v.16 no.2
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    • pp.219-240
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    • 2003
  • One of the most versatile approaches for analyzing the dynamic behavior of structural systems is direct time integration of semi-discrete equations of motion. However responses computed by time integration are generally inexact and hence the corresponding errors would rather be studied in advance. In spite of the various error estimation formulations that exist in the literature, it is accepted practice to repeat the analyses with smaller time steps, followed by a comparison between the results. In this paper, after a review of this simple method and disregarding the round-off errors, a more efficient, reliable and yet simple method for estimating errors and enhancing the accuracy is proposed. The main objectives of this research are more realistic error estimation based on the concept of convergence, approximately controlling the reliability by comparing the actual rate of convergence with the integration method's order of accuracy, and enhancement of reliability by applying Richardson's extrapolation. Starting from the errors at specific time instants, the study is then generalized to cases in which the errors should be estimated and decreased at specific events e.g. peak responses. Numerical study illustrates the efficacy of the proposed method.

The Construction of an Early Childhood Teacher Efficacy Scale (유아 교사 효능감 척도 개발 연구)

  • Kim, Sun-Young;Seo, So-Jung
    • Korean Journal of Child Studies
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    • v.31 no.4
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    • pp.91-110
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    • 2010
  • The purpose of this study was to develop a valid and reliable early childhood teacher efficacy scale. As part of this process, the final version of the early childhood teacher efficacy scale was examined in order to reflect the characteristics of the subjects who participated in this study, namely, 598 in-service teachers employed at kindergartens and child care centers. Our data was analyzed according to both the reliability and validity of the scale. the main results of this study were as follows. The overall internal consistency was relatively high (Cronbach's ${\alpha}$ = .91~.93). In addition, the content reliability was examined by a panel of experts in the field. The results of the factor analyses identified 6 sub-constructs with 59 items, thus clearly establishing the construct validity. Moreover, the concurrent validity of this scale was established. The results of correlational and t-test analyses found that the constructs of this scale reflected the characteristics of early childhood teachers.

Probabilistic study on buildings with MTMD system in different seismic performance levels

  • Etedali, Sadegh
    • Structural Engineering and Mechanics
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    • v.81 no.4
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    • pp.429-441
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    • 2022
  • A probabilistic assessment of the seismic-excited buildings with a multiple-tuned-mass-damper (MTMD) system is carried out in the presence of uncertainties of the structural model, MTMD system, and the stochastic model of the seismic excitations. A free search optimization procedure of the individual mass, stiffness and, damping parameters of the MTMD system based on the snap-drift cuckoo search (SDCS) optimization algorithm is proposed for the optimal design of the MTMD system. Considering a 10-story structure in three cases equipped with single tuned mass damper (STMS), 5-TMD and 10-TMD, sensitivity analyses are carried out using Sobol' indices based on the Monte Carlo simulation (MCS) method. Considering different seismic performance levels, the reliability analyses are done using MCS and kriging-based MCS methods. The results show the maximum structural responses are more affected by changes in the PGA and the stiffness coefficients of the structural floors and TMDs. The results indicate the kriging-based MCS method can estimate the accurate amount of failure probability by spending less time than the MCS. The results also show the MTMD gives a significant reduction in the structural failure probability. The effect of the MTMD on the reduction of the failure probability is remarkable in the performance levels of life safety and collapse prevention. The maximum drift of floors may be reduced for the nominal structural system by increasing the TMDs, however, the complexity of the MTMD model and increasing its corresponding uncertainty sources can be caused a slight increase in the failure probability of the structure.

Development and Validation of a Recognition Scale for Childcare Teachers' Rights (보육교사 권리 인식 척도 개발 및 타당화)

  • Jaekyeong Suk;Jungmin Kim
    • Korean Journal of Childcare and Education
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    • v.19 no.6
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    • pp.1-19
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    • 2023
  • Objective: The aim of the present study was to develop and validate a recognition scale for childcare teachers' rights. Methods: Statistical methods for data analysis involved the use of SPSS 20.0 and AMOS 20.0. To confirm the reliability and validity of the developed scale, various analyses, including item quality assessment, item discrimination, exploratory factor analysis, confirmatory factor analysis, and Pearson correlation analysis, were conducted. The maximum likelihood estimation method was employed for model fitting. Goodness of fit was assessed using SRMR, RMSEA and its 90% confidence interval, CFI, and TLI. Through these analyses, the scale's reliability and validity exceeded the standard. Consequently, 5 factors and 30 questions were ultimately selected as the recognition scale for childcare teachers' rights. Results: First, a recognition scale for childcare teachers' rights was developed to reflect changes in childcare settings. Second, an objective measurement was incorporated into the recognition scale of childcare teachers' rights. Third, the analysis using the proposed scale revealed a correlation between the recognition of childcare teachers' rights and life satisfaction. Conclusion/Implications: The study developed a scale capable of objectively measuring the recognition of childcare teachers' rights.

A new methodology of the development of seismic fragility curves

  • Lee, Young-Joo;Moon, Do-Soo
    • Smart Structures and Systems
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    • v.14 no.5
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    • pp.847-867
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    • 2014
  • There are continuous efforts to mitigate structural losses from earthquakes and manage risk through seismic risk assessment; seismic fragility curves are widely accepted as an essential tool of such efforts. Seismic fragility curves can be classified into four groups based on how they are derived: empirical, judgmental, analytical, and hybrid. Analytical fragility curves are the most widely used and can be further categorized into two subgroups, depending on whether an analytical function or simulation method is used. Although both methods have shown decent performances for many seismic fragility problems, they often oversimplify the given problems in reliability or structural analyses owing to their built-in assumptions. In this paper, a new method is proposed for the development of seismic fragility curves. Integration with sophisticated software packages for reliability analysis (FERUM) and structural analysis (ZEUS-NL) allows the new method to obtain more accurate seismic fragility curves for less computational cost. Because the proposed method performs reliability analysis using the first-order reliability method, it provides component probabilities as well as useful byproducts and allows further fragility analysis at the system level. The new method was applied to a numerical example of a 2D frame structure, and the results were compared with those by Monte Carlo simulation. The method was found to generate seismic fragility curves more accurately and efficiently. Also, the effect of system reliability analysis on the development of seismic fragility curves was investigated using the given numerical example and its necessity was discussed.

Bayesian Reliability Analysis Using Kriging Dimension Reduction Method(KDRM) (크리깅 기반 차원감소법을 이용한 베이지안 신뢰도 해석)

  • An, Da-Un;Choi, Joo-Ho;Won, Jun-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.3
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    • pp.275-280
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    • 2008
  • A technique for reliability-based design optimization(RBDO) is developed based on the Bayesian approach, which can deal with the epistemic uncertainty arising due to the limited number of data. Until recently, the conventional REDO was implemented mostly by assuming the uncertainty as aleatory which means the statistical properties are completely known. In practice, however, this is not the case due to the insufficient data for estimating the statistical information, which makes the existing RBDO methods less useful. In this study, a Bayesian reliability is introduced to take account of the epistemic uncertainty, which is defined as the lower confidence bound of the probability distribution of the original reliability. In this case, the Bayesian reliability requires double loop of the conventional reliability analyses, which can be computationally expensive. Kriging based dimension reduction method(KDRM), which is a new efficient tool for the reliability analysis, is employed to this end. The proposed method is illustrated using a couple of numerical examples.

Evaluation of Reliability Index of Governing Load Combination for Design of Cable Supported Bridge Members (케이블교량의 부재 설계를 지배하는 하중조합에 대한 신뢰도지수 평가)

  • Paik, Inyeol;Yoon, Taeyong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.643-651
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    • 2014
  • In this paper the reliability analyses of the cable-supported bridge design code which is recently issued in Korea are performed and the results are presented. Governing load combinations for the member design and the statistical properties of the main members are introduced and the analysis is performed using an example cable-stayed bridge for which the design is performed following the load and resistance factors defined in the design code. The reliability analysis shows the target reliability index can be achieved by applying load and resistance factors and the application of the resistance modification factor can enhance the reliability level if the importance of the bridge needs to be increased. The sensitivity analysis reveals that decreasing uncertainty of the cable strength is critical for obtaining the target reliability index. The study results show that the design using the load and resistance factors of the code can achieve the target reliability indexes for the design of cable supported bridge.

Probability of Failure on Sliding of Monolithic Vertical Caisson of Composite Breakwaters (혼성제 직립 케이슨의 활동에 대한 파괴확률)

  • 이철응
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.2
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    • pp.95-107
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    • 2002
  • A reliability analysis on sliding of monolithic vertical caisson of composite breakwaters is extensively carried out in order to make the basis for the applicability of reliability-based design method. The required width of caisson of composite breakwaters is determined by the deterministic design method including the effect of impulsive breaking waves as a function of water depth, also studied interactively with the results of reliability analyses. It is found that the safety factor applied in current design may be a little over-weighted magnitude for the sliding of caisson. The reliability index/failure probability is also seen to slowly decrease as the water depth increases for a given wave condition and a safety factor. In addition, optimal safety factor can roughly be evaluated by using the concept of target reliability index for several incident waves. The variations of optimal safety factor may be resulted from the different wave conditions. Finally, it may be concluded from the sensitivity studies that the reliability index may be more depended on the incident wave angles and the wave periodsrather than on the bottom slopes and the thickness of rubble mound.

Development of the Meaning in Life Scale for Older Adults (노인의 삶의 의미 측정 도구 개발)

  • Lee, Si Eun;Hong, Gwi-Ryung Son
    • Journal of Korean Academy of Nursing
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    • v.47 no.1
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    • pp.86-97
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    • 2017
  • Purpose: The purpose of this study was to develop and test the psychometric properties of the newly developed instrument, Meaning in Life, for elderly Korean people. Methods: Ten older adults participated in the qualitative research used to develop the initial items. Participants for the psychometric testing were 371 community-dwelling older adults. Validity and reliability analyses included content, construct, and criterion-related validities, internal consistency, and test-retest reliability. Results: The Meaning in Life Scale consisted of 12 items with three distinct factors; value of life, source of life, and will to live, which explained 86.7% of the total variance. A three-factor structure was validated by confirmatory factor analysis. Criterion-related validity was supported by comparison with the Purpose in Life Test (r=.74). Reliabilities were secured with test-retest reliability of Intra-class Correlation Coefficient (ICC) .85 and the Cronbach's alpha coefficient .90. Conclusion: The results of this study indicate that this instrument is useful to measure meaning in life in Korean elders.