• Safety and Health at Work
• /
• v.13 no.2
• /
• pp.170-179
• /
• 2022

Background: The vulnerability of international migrant workers is on the rise, affecting the frequency of occupational accidents at workplaces worldwide. If migrant workers are managed in the same way as native workers, the consequences on safety assurance and risk management will be significant. This study aimed to develop the vulnerability factor model for migrant workers in seafood processing industries because of significant risk-laden labor of Thailand, which could be a solution to control the risk effectively. Methods: A total of 569 migrant workers were surveyed (432 Burmese and 137 Cambodian), beginning with 40 initial vulnerability factors identified in the questionnaire established from experts. The data were analyzed through descriptive analysis; exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to ascertain the model. Results: The result of content validity >0.67 and the Cronbach's alpha of 0.957 specified the high reliability of 40 factors. The EFA indicated a total variance of 65.49%. The final CFA validated the model and had an empirical fitting; chi-square = 85.34, Adjust Goodness-of-Fit Index = 0.96, and root mean square error of approximation = 0.016. The structure concluded with three dimensions and 18 factors. Dimension 1 of the structure, "multicultural safety operation," contained 12 factors; Dimension 2, "wellbeing," contained four factors; and Dimension 3, "communication technology," contained two factors. Conclusion: The vulnerability factor structure developed in this study included three dimensions and 18 factors that were significantly empirical. The knowledge enhanced safety management in the context of vulnerability factor structure for migrant workers at the workplace.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.2126-2127
• /
• 2011

This paper describes the analysis of deterioration characteristics for connection factor according to connection method of grounding system. The connection method of grounding system is specified in IEC standard. In order to analyze the deterioration characteristics for connection factor, deterioration test was carried out when the connection factor was buried in salt water and underground. The test connection factors were C-type sleeve, clamp, and exothermic welding. As a consequence, most of the connection factor was corroded, and the electrical resistance decreased after deterioration. The analytical results can be used to establish the safety of grounding system.

• Wind and Structures
• /
• v.24 no.3
• /
• pp.249-265
• /
• 2017

An efficient and accurate algorithm is proposed to estimate flutter safety factor of suspension bridges satisfying prescribed reliability levels. Uncertainties which arise from the basic wind speed at the bridge deck location, critical flutter velocity, the wind conversion factor from a scaled model to the prototype structure and the gust speed factor are incorporated. The proposed algorithm integrates the concepts of the inverse reliability method and the calculation method of the critical flutter velocity of suspension bridges. The unique feature of the proposed method is that it offers a tool for flutter safety assessment of suspension bridges, when the reliability level is specified as a target to be satisfied by the designer. Accuracy and efficiency of this method with reference to three example suspension bridges is studied and numerical results validate its superiority over conventional deterministic method. Finally, the effects of various parameters on the flutter safety factor of suspension bridges are also investigated.

• Geomechanics and Engineering
• /
• v.24 no.4
• /
• pp.399-406
• /
• 2021

It is a key issue in the tunnel design to evaluate the stability of the excavation face. Two efficient analytical models in the context of the limit equilibrium method (LEM) and the limit analysis method (LAM) are used to carry out the deterministic calculations of the safety factor. The safety factor obtained by these two models agrees well with that provided by the numerical modelling by FLAC 3D, but consuming less time. A simple probabilistic approach based on the Mote-Carlo Simulation technique which can quickly calculate the probability distribution of the safety factor was used to perform the probabilistic analysis on the tunnel face stability. Both the cumulative probabilistic distribution and the probability density function in terms of the safety factor were obtained. The obtained results show the effectiveness of this probabilistic approach in the tunnel design.

• Tunnel and Underground Space
• /
• v.29 no.5
• /
• pp.346-355
• /
• 2019

When evaluating pillar stability in very closely spaced tunnels, a local safety factor (strength/stress ratio) at the minimum width has been widely used. Tension bolts have been frequently applied as reinforcement for the cases where safety factors are less than 1.0 from FEM stress analysis. However, the local safety factor shows a constant value irrespective of the change in pillar width/tunnel diameter (PW/D) and the safety factor of the pillar is underestimated because the variation of deviation stress is relatively small even when the pre-stressing is applied to the tension bolt. In addition, the average safety factor proposed by Hoek and Brown(1980) was reviewed, but the pillar safety factor was relatively overestimated when the width of the pillar was increased. As an alternative, the SRM safety factor using shear strength reduction method shows the effect of changing the safety factor in the case of no reinforcement and tension bolt reinforcement as the pillar width/tunnel diameter(PW/D) changes. The failure shape is also similar to the previous limit theory result. In this study, the safety factor was evaluated without considering rock bolt and shotcrete to distinguish reinforcing effect of tension bolt.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.129-136
• /
• 2005

The deterministic analysis method has generally used to evaluate the slope stability and it evaluates the slope stability with decision value that is a representative value of design variables. However, one of disadvantages in the deterministic approach is there is not able to consider the uncertainty of soil strength properties, even though it is the biggest influential parameter of the slope stability. On the other hand, the limit state design(LSD) can take a consideration of uncertainties and computes both the reliability index and the probability of failure. LSD method is capable of overcoming the disadvantages of deterministic method and evaluating the slope stability more reliably. In this study, both the mean value and standard deviation of the internal land's representative soil strength properties applied to process the LSD method. The major purpose of this study is to gauge the general applicability of the limit state design in soil slope and to weigh the comparative validity of the proposed partial safety factor. In order to reach the aim of this study, the partial safety factor and resistance factor which totally satisfied the slope's overall safety factor were calculated by the load and resistance safety factor design (LRFD).

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.13 no.6 s.58
• /
• pp.183-191
• /
• 2009

In this study, the behavior and safety factor of a nailed-soil excavation wall during earthquake is presented. The horizontal displacement, axial force, shear force, and moment of facing of a nailed-soil excavation wall subjected to static and seismic load are analyzed using time history analysis. The safety factor based on the strength reduction technique proposed by Dawson and Roth is used to calculate the safety factor of a nailed-soil excavation wall during earthquake. The safety factor by the proposed method is verified by comparing with those by other methods.

• Proceedings of the Safety Management and Science Conference
• /
• 2009.11a
• /
• pp.657-665
• /
• 2009

The paper reviews gauge R&R studies by two-factor mixed models including random and fixed factors. The two-factor mixed models include restricted models and unrestricted models considering the interaction of two factors. This study also classifies the models according to the number of factors, and the combination of various factors such as random factor, fixed factor, block factor and repetition type.

• 한국방재학회:학술대회논문집
• /
• 2007.02a
• /
• pp.376-379
• /
• 2007

In recent years, the natural damage associated with flood disaster has been dramatically increased. However, there is no rational method which reflects urban characteristics to estimate the regional safety assessment for flood disaster. The purpose of this study is to develop the regional safety assesment model for urban flood. Flood risk and reduction assesment were estimated by using the linear sum of the Z score of the assessment factors and the weight value of each factor from the expert survey data. And then the regional safety assessment was estimated by subtracting reduction factor value from risk factor value. GIS tool was used to estimate the factor assesment and integrated regional safety. This study can be used to determine the priority of flood protection project, execute the flood insurance and establish the urban plans and the flood mitigate plan.

• Journal of the Korean Geosynthetics Society
• /
• v.15 no.2
• /
• pp.13-24
• /
• 2016

The safety factor of an infinite slope tends to be analyzed as lower when the effects of root cohesion are not considered into the equation. Thus, it is essential to consider regional characteristics such as root cohesion and crown density in order to obtain a reasonable safety factor value. In this study, The safety factor of the landslide model, both before and after considering crown density and root cohesion, was calculated and a comparative analysis was carried out. The safety factor is increased by the effect of roots cohesion of the analysis results, the amount of increase in safety factor along the inclination of the slope angle has been analyzed with various things, the effect of reinforcing the roots cohesion, slope of the lower angle it was found that the higher the safety factor increase.