• Structural Engineering and Mechanics
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• v.89 no.4
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• pp.399-409
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• 2024

Assessment of existing concrete bridges is a challenge for owners. It has greater economic impact when compared to designing new bridges. When using conventional linear analyses, judgment of the engineer is required to understand the behavior of redundant structures after the first element in the structural system reaches its ultimate capacity. The alternative is to use a predictive tool such as advanced nonlinear finite element analyses (ANFEA) to assess the overall structural behavior. This paper proposes a new reliability framework for the assessment of existing bridge structures using ANFEA. A general framework defined in previous works, accounting for material uncertainties and concrete model performance, is adapted to the context of the assessment of existing bridges. A "shifted" reliability problem is defined under the assumption of quasi-deterministic dead load effects. The overall exercise is viewed as a progressive pushover analysis up to structural failure, where the actual safety index is compared at each event to a target reliability index.

• Journal of the Korea Society of Computer and Information
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• v.28 no.3
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• pp.149-157
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• 2023

The purpose of this study is to suggest that performers in the performing arts actively utilize the loading dock and stage door when evacuating from the stage space of a performance hall in a crisis situation. Therefore, first, we analyzed the system related to the performance hall's safety. The stage evacuation type was classified into A, B, C, and D forms by applying the building law audience evacuation standards. Second, statistical data were organized based on measurement data, and the characteristics of each form were summarized. Third, the network reliability measurement method was borrowed to evaluate the evacuation safety of the evacuation route in the stage space. We confirmed quantitatively that the direction of the loading dock direction and stage door direction on the stage is advantageous for evacuation. In this study, it was possible to distinguish the advantage of evacuation according to the type of evacuation, (A(0.1274)>B(0.1228).>.C(0.0487)) with A being the most advantageous. These results can be expected to improve the evacuation safety of the stage, and furthermore, they are expected to be used as basic data for stage evacuation.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.55-64
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• 2016

In this paper bearing capacity and safety margin of shallow foundation on weathered soil ground against shear failure by using current design method of allowable stress design (ASD), load resistance factor design (LRFD) based on reliability analysis and partial safety factor design (PSFD) in Eurocode were estimated and compared to each other. Results of the plate loading test used in construction and design were collected and analysis of probability statistics on soil parameters affecting the bearing capacity of shallow foundation was performed to quantify the uncertainty of them and to investigate the resistance bias factor and covalence of ultimate bearing capacity. For the typical sections of shallow foundation in domestic field as examples, reliability index was obtained by reliability analysis (FORM) and the sensitivity analysis on soil parameters of probability variables was performed to investigate the effect of probability variable on shear failure. From stability analysis for these sections by ASD, LRFD with the target reiability index corresponding to the safety factor used in ASD and PSDF, safety margins were estimated respectively and compared.

• Korea Trade Review
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• v.45 no.1
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• pp.259-277
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• 2020

The purpose of this study is to analyze the relationship between logistics safety climate, logistics safety behavior, and logistics safety performance and the mediating effects of safety knowledge and safety motivation, and to suggest its strategic implications for the improvement of the logistics safety performance. Based on previous researches related to logistics safety, safety climate, safety knowledge, safety motivation, safety behavior and safety performance, research models and hypotheses were set up and questionnaires were conducted. For the hypothesis test, reliability analysis and validity analysis, confirmatory factor analysis, structural equation model analysis, and bootstrapping were applied. As a result of the empirical analysis, the logistics safety climate had a significant positive effect on logistics safety knowledge, logistics safety motivation, and logistics safety behavior, whereas logistics safety knowledge and logistics safety motivation had a meaningful positive effect on logistics safety behavior. Further, logistics safety behavior was found to have a significant positive effect on logistics safety performance. Safety behavior had a significant mediating effect, but safety knowledge and safety motivation did not. However, logistics safety climate, logistics safety knowledge, and logistics safety motivation did not have a significant effect on logistics safety performance.

• Journal of Applied Reliability
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• v.17 no.1
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• pp.38-49
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• 2017

Purpose: The purpose of this study is to introduce the assessment model for industrial accidents prevention policy. Methods: 10 years of industrial accidents data are explored through EDA approach. Case control study is tried in order to assess the effectiveness of the measures taken by Korea Safety and Health Agency, Civilian, and 'Ministry of Employment and Labor'. Propensity score matching is used to match the characteristics of the two groups compared, and then case control study is again conducted. Next, logistic and Poisson regressions are used to assess the risk factors. Results: According to case control study involvement of 'Korea Safety and Health Agency' and 'Ministry of Employment and Labor' were not effective, but Civilian was. Propensity score matching leads to the same conclusion. Poisson regression reveals the impact of the risk factors on the industrial accidents. Industrial accidents occur more often as the number of employees grows. Mining, farming, fishing, 'transportation storage and telecommunication' and forestry have a higher level of industrial accidents but service industry has a lower level. It is odd that more involvement of Korea Safety and Health Agency, Civilian, and Ministry of Employment and Labor means more industrial accidents. Conclusion: 'Korea Safety and Health Agency', Civilian, and 'Ministry of Employment and Labor' seem to visit those industries with more industrial accidents.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.2
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• pp.168-175
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• 2020

Failure of essential avionic equipments have a significant impact on the operations and safety of P-3 maritime patrol aircraft. Therefore, avionic equipments of P-3 are required to have higher reliability. Based on the field failure data, this paper studies the reliability growth of essential avionic equipments in P-3 using Duane model. Additionally, a simulation model is built and implemented for identifying the operational availability according to the field failure data of avionic equipments.

• Computers and Concrete
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• v.17 no.1
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• pp.87-106
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• 2016

This paper deals with the reliability analysis of design formulations derived for predicting the punching shear capacity of FRP-reinforced two-way slabs. Firstly, a new design code formulation was derived by means of gene expression programming. This formulation differs from the existing ones as the slab length (L) was introduced in the equation. Next, the proposed formulation was tested for its generalization capability by a parametric study. Then, the stochastic analyses of derived and existing formulations were performed by Monte Carlo simulation. Finally, the reliability analyses of these equations were carried out based on the results of stochastic analysis and the ultimate state function of ASCE-7 and ACI-318 (2011). The results indicate that the prediction performance of new formulation is significantly higher as compared to available design equations and its reliability index is within acceptable limits.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.1-7
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• 2007

This paper addresses a the maintenance system based on the concept of RAMS (Reliability, Availability, Maintenance, Safety) for the effective maintenance of the urban transit. A systematic approach for developing a cost-effective maintenance strategy based on the component reliability of the system in question is performed according to the following steps : definition of function, functional failures of the systems, construction of RBD (Reliability Block Diagram), and the calculation of reliability indices. The developed preventive maintenance system generates maintenance plan and repair request based on the analysed RAMS data of components and maintenance experience.

• The Korean Journal of Food And Nutrition
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• v.24 no.2
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• pp.166-172
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• 2011

This study was conducted to assess food safety knowledge of college students according to mass-media reports. To accomplish this, a survey was conducted to investigate the reliability, of primary mass-media sources on Bovine Spongiform Encephalopathy(BSE) as well as the preferences of college students. The most common sources of media consumed by male and female students were terrestrial television(TV)(60%), the internet(21%), and newspapers(11%) and terrestrial TV(60%), newspapers (18%), and the internet(17%), respectively. The preferences for media of major and non-major students were terrestrial TV(64%), newspapers(17%), and the internet(14%) and terrestrial TV(51%), the internet(22%), and newspapers(19%), respectively. The reliability of media as viewed by male students were as follows: terrestrial TV(53%) and the internet(40%), whereas for female students, these values were terrestrial TV(55%) and the internet(37%). The reliability of media as viewed by major and non-major students was as follows: terrestrial TV(67%) and the internet(28%), and terrestrial TV(44%) and the internet(44%), respectively. In the case of male students, the primary sources for information regarding BSE were terrestrial TV(54%) and the internet(38%), whereas for female students, the primary sources were terrestrial TV(57%) and internet (37%). In the case of major students, the primary sources for information regarding BSE were terrestrial TV(52%) and the Internet(40%), and for non-major students, the internet(47%) and terrestrial TV(39%). Both male and female students were found to have less knowledge regarding prions, SRM(Specified Risk Materials), MM(methionine-methionine) type genes, and cow above 30 months associated with BSE compared to the other factors associated with this disease. The BSE-related knowledge held by major and non-major students was revealed unknown more than the majority of responses. Based on these results, greater effort should be made to provide meaningful information to improve the food-safety knowledge of college students according to mass-media.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.235-242
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• 2005

This study introduces the Reliability-Based Design Optimization (RBDO) to enhance the kinematic and compliance (K & C) characteristics of automotive suspension system. In previous studies, the deterministic optimization has been performed to enhance the K & C characteristics. Unfortunately, uncertainties in the real world have not been considered in the deterministic optimization. In the design of suspension system, design variables with the uncertainties, such as the bushing stiffness, have a great influence on the variation of the suspension performances. There is a need to quantify these uncertainties and to apply the RBDO to obtain the design, satisfying the target reliability level. In this research, design variables including uncertainties are dealt as random variables and reliability of the suspension performances, which are related the K & C characteristics, are quantified and the RBDO is performed. The RBD-optimum is compared with the deterministic optimum to verify the enhancement in reliability. Thus, the reliability of the suspension performances is estimated and the RBD-optimum, satisfying the target reliability level, is determined.