• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.53-62
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• 1998

International Maritime Organizatin(IMO) has been chosen some of agreements for regulating the international stability criteria of fishing vessels and recommended that each goverment adopts theirs into the domestic law. As a result, 77/93 Fishing Safety Agreement was ratified. Among the above agreement, contents of stability was not only applied to domestic law, but also strenghten considerably compared with existing stability criteria. And even if the calculation guide of stability with recommendations was regualted, Analysis of stability on domestic fishing vessels never have been used according to such a caculation method. Moreover, the caculation of stability criteria caused by strong wind, rolling effect and deck inflow was not considered in the existing basic design program. Therefore, the development of stability criteria program available for such a caculation has been of vital impotance. This research has developed a stability criteria program under 77/93 Fishing Safety Agreement. Also through development of stability criteria program, the stability performance of fishing vessel with 69ton stow-nesting was evaluated.

• Journal of the Korean Society of Safety
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• v.30 no.2
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• pp.1-8
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• 2015

Forklift truck is a very convenient transportation vehicle and widely used in industries. However, a lot of overturn accidents occur during operation because of poor understanding on the stability of forklift trucks. The stability of a forklift is defined by the minimum slope of the ramp where a forklift truck overturns. According to the KS BISO 22915-2 code, the stability is determined from the four kinds of stability tests. The equations for the stability of a forklift truck were proposed already in several published literatures and the equations can be used conveniently to estimate the stability and examine the effects of design parameters in forklift trucks. However, because the detail derivation procedure was omitted, it is very difficult to examine the accuracy of the proposed equations and to modify the equations for other types of forklift trucks. In this paper the stability equations were derived again with detail derivations for the four kinds of stability tests. And the effects of acceleration or centrifugal forces were also additionally included in the equations and minor corrections were also made.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.3 s.153
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• pp.285-295
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• 2007

In order to ensure safety of small vessels, the amended Ship Safety Act will come into force on 4th. Nov. 2007. This study is performed to suggest the stability criteria of fishing vessels and cargo ships of 12m in length and over but less than 24m in length which will be new object of amended Ship Safety Act. We have analyze the dimensions of domestic small vessels and the casualty reports of capsizing accidents. According to the analyzed result, 58 ships that are in the range of the dimension are modeled and the stability calculation has been carried out. The Stability for the 58 ships has been analyzed by comparing the result that applied the selected standard in the national standard to the stability calculation. Based on the regression analysis of the model ship's allowable transverse metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

• Safety and Health at Work
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• v.3 no.3
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• pp.192-198
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• 2012

Objectives: Slip and fall accidents in the workplace are one of the top causes of work related fatalities and injuries. Previous studies have indicated that fall risk was related to postural and dynamic stability. However, the usage of this theoretical relationship was limited by laboratory based measuring instruments. The current study proposed a new method for stability assessment by use of inertial measurement units (IMUs). Methods: Accelerations at different body parts were recorded by the IMUs. Postural and local dynamic stability was assessed from these measures and compared with that computed from the traditional method. Results: The results demonstrated: 1) significant differences between fall prone and healthy groups in IMU assessed dynamic stability; and 2) better power of discrimination with multi stability index assessed by IMUs. Conclusion: The findings can be utilized in the design of a portable screening or monitoring tool for fall risk assessment in various industrial settings.

• Safety and Health at Work
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• v.4 no.1
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• pp.46-51
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• 2013

Objectives: Load carrying tasks are recognized as one of the primary occupational factors leading to slip and fall injuries. Nevertheless, the mechanisms associated with load carrying and walking stability remain illusive. The objective of the current study was to apply local dynamic stability measure in walking while carrying a load, and to investigate the possible adaptive gait stability changes. Methods: Current study involved 25 young adults in a biomechanics research laboratory. One tri-axial accelerometer was used to measure three-dimensional low back acceleration during continuous treadmill walking. Local dynamic stability was quantified by the maximum Lyapunov exponent (maxLE) from a nonlinear dynamics approach. Results: Long term maxLE was found to be significant higher under load condition than no-load condition in all three reference axes, indicating the declined local dynamic stability associated with load carrying. Conclusion: Current study confirmed the sensitivity of local dynamic stability measure in load carrying situation. It was concluded that load carrying tasks were associated with declined local dynamic stability, which may result in increased risk of fall accident. This finding has implications in preventing fall accidents associated with occupational load carrying.

• Geomechanics and Engineering
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• v.34 no.3
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• pp.329-339
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• 2023

The objective of this study is to develop a Stability Evaluation System for retaining walls to assess their safety in real-time during excavation. A ground investigation is typically conducted before construction to gather information about the soil properties and predict wall stability. However, these properties may not accurately reflect the actual ground being excavated. To address this issue, the study employed a differential evolution algorithm to estimate the soil parameters of the actual ground. The estimated results were then used as input for an artificial neural network to evaluate the stability of the retaining walls. The study achieved an average accuracy of over 90% in predicting differential settlement, wall displacement, anchor force, and structural stability of the retaining walls. If implemented at actual excavation sites, this approach would enable real-time prediction of wall stability and facilitate effective safety management. Overall, the developed Stability Evaluation System offers a promising solution for ensuring the stability of retaining walls during construction. By incorporating real-time soil parameter analysis, it enhances the accuracy of stability predictions and contributes to proactive safety management in excavation projects.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.86-92
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• 2009

In the safety check of gravity dams at earthquake, there have been two types of analysis conducted simultaneously; one is stability analysis and the other stress analysis. But those are essentially the same calculation other than the former considers the dams rigid, while the latter considers the dams' dynamic characteristics which results in the amplification of response acceleration on the upper part of dam body. In this paper, the identity of those two methods is verified by example calculation in terms of stability check of gravity dam. It can be concluded that if stress analysis were performed, stability check of gravity dam could be accomplished with the results from stress analysis, removing unnecessary present dual calculation practice.

• Geomechanics and Engineering
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• v.33 no.2
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• pp.141-154
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• 2023

This study investigated the effect of water retention characteristics between aged and fresh Municipal Solid Waste (MSW) on the stability of the landfill. A series of transient numerical modeling for the slope of an MSW landfill was performed considering the variation of water retention characteristics due to leachate circulation. Four different scenarios were considered in this analysis depending on how to obtain hydraulic conductivity and the aging degree of materials. Unsaturated hydraulic properties of the MSW used for the modeling were evaluated through modified hanging column tests. Different water retention properties and various landfill conditions, such as subgrade stiffness, leachate injection frequency, and gas and leachate collection system, were considered to investigate the pore water distribution and slope stability. The stability analyses related to the factor of safety showed that unsaturated properties under those varied conditions significantly impacted the slope stability, where the factor of safety decreased, ranging between 9.4 and 22%. The aged materials resulted in a higher factor of safety than fresh materials; however, after 1000 days, the factor of safety decreased by around 10.6% due to pore pressure buildup. The analysis results indicated that using fresh materials yielded higher factor of safety values. The landfill subgrade was found to have a significant impact on the factor of safety, which resulted in an average of 34% lower factor of safety in soft subgrades. The results also revealed that a failed leachate collection system (e.g., clogging) could result in landfill failure (factor of safety < 1) after around 298 days, while the leachate recirculation frequency has no critical impact on stability. In addition, the accumulation of gas pressure within the waste body resulted in factor of safety reductions as high as 24%. It is essential to consider factors related to the unsaturated hydraulic properties in designing a landfill to prevent landfill instability.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.129-136
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• 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 Korean Society of Safety
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• v.31 no.3
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• pp.102-108
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• 2016

As a range of accidents happen frequently in our society due to safety insensitivity, researches on individual psychological characteristics related to safety behavior and on safety education are increasing. However, safety behavior research that targets university students as potential employees remains rare. Therefore, this research investigates individual characteristics and psychological factors that affect safety behaviors of university students. Research participants were 131 university students (80 males, 51 females) from the Gyeonggi-do and Chungnam areas. Psychological characteristics (self-regulation, cognitive failure, conscientiousness, and emotional stability) were included as variables that may predict university students' safety behaviors (habits, compliance, mistakes, and violations). The major findings of the study are as follows. Stepwise regression analysis showed conscientiousness was a major predictor explaining safety habits and safety compliance; Cognitive failure and emotional stability were main predictors explaining safety mistakes, and self-regulation was a major predictor explaining safety violations. These findings suggest that development of proper education programs focusing on individual characteristics would allow systematic improvement of safety behaviors of university students.