• Progress in Medical Physics
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• v.29 no.1
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• pp.42-46
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• 2018

The purpose of this study was to perform a survey of the radiation shielding design goals (P) and workload (W) based on the radiation safety reports concerned with structural shielding design for the IMRT treatment technique in Tomotherapy vaults. The values of the P and W factors as well as of a verified concrete thickness of the ceiling, bottom, sidewalls (sidewall-1 and sidewall-2), and door have been obtained from radiation safety reports for a total of 16 out of 20 vaults. The recommended and most widely used report for P values was the NCRP No. 151 report, which stated that the P factor in controlled and uncontrolled areas was 0.1 and 0.02 mSv/week, respectively. The range of the W factor was 600~14,720 Gy/week. The absorbed dose delivered per patient was 2~3 Gy. The maximum number of patients treated per day was 10~70. The quality assurance (QA) dose was 100~1,000 Gy/week. Fifteen values of the IMRT factor (F) were mostly used but a maximum of 20 values was also used. The concrete thickness for primary structures including the ceiling, bottom, sidewalls, and door was sufficient for radiation shielding. The P and W factors affect the calculation of the structural shielding design, and several parameters, such as the absorbed dose, patients, QA dose, days and F factor can be varied according to the type of shielding structure. To ensure the safety of the radiation shielding, it is necessary to use the NCRP No. 151 report for the standard recommendation values.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.67-74
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• 2021

This paper evaluated the structural safety of an aging PSC I-girder bridge with rebar corrosion in the deck. The geometry and rebar of the bridge were designed based on an actual PSC I-girder bridge, and the numerical analysis was performed considering the crack of concrete and yielding of steel rebar. According to the evaluation criteria of Korea Infrastructure Safety and Technology Corporation, this study defined two criteria of rebar exposure and corrosion rates to construct a total of 32 corrosion scenarios. Rebar exposure was defined as the exposure of tensile rebars in the bridge deck due to the removal of cover concrete. The results of the analysis showed that the safety and rating factors of the bridge decreased with increasing rebar exposure and corrosion rates. For the rebar corrosion rate more than 50%, the safety grade of the bridge should be carefully evaluated for all the rebar exposure rate. When the rebar corrosion rate exceeds 57%, the bridge was evaluated as E grade regardless of rebar exposure rate. A correlation analysis for a 2% of rebar exposure rate found that the bridge was evaluated as A grade up to 55.8% corrosion rate, C grade up to 56.9%, D grade up to 58.5%, and E grade for corrosion rate greater than 58.5%. This study indicates the necessity of a quantitative evaluation of rebar corrosion for evaluating the structural safety of aging bridges.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.4
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• pp.37-44
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• 2019

The purpose of this study is to rationally determine the priority of seismic reinforcement of main(key) members of bridges. Cable Supported bridge was selected as the evaluation target and the reliability based on the probability distribution was used to evaluate the seismic fragility of the key members as a quantitative indicator. The safety factor, which is a random variable, is considered an artificial (fixed load and live load) load and a natural (earthquake, wind, temperature, etc.) load. The seismic load is applied as a possible earthquake during the lifetime of the bridge. From analyzing the fragility of each key member based on the seismic reliability, it can be concluded that the shoe (23.8%) was the most fragile, where the other members are ranked as place concrete (20.5%), pier (18.9%), foundation (17.3%) and cable (5.0%) respectively.

• Journal of Korean Academy of Nursing
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• v.44 no.2
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• pp.119-128
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• 2014

Purpose: This study is an examination of the paths in which the primary factors of anxiety, impulsiveness, knowledge of life safety practice, attitudes towards life safety practice, interpersonal support, and self-efficacy from Pender's Health Promotion Model influence the practice of life safety behavior in school-age children. Methods: The sample consisted of 489 5th and 6th grade students recruited from five elementary schools in Seoul City and four provinces, South Korea. Data were analyzed using descriptive statistics, correlations, factor analysis, and structural equation modeling. Results: Attitudes towards life safety practice, interpersonal support, self-efficacy and impulsiveness directly influenced practice of life safety behavior. Anxiety did not have a direct influence on practice of life safety behavior, but indirectly affected it. In this modified model, 52.0% of the practice of life safety behavior was explained by the primary factors. Conclusion: To facilitate the practice life safety behaviors in late childhood, a positive attitude towards life safety needs to be developed along with decreasing impulsiveness and enhancing self-efficacy.

• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.162-170
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• 2005

The effective development of event product for a successful event is first started with figuring out the participation motive of event. Second, what level of expectation before participating event for participant will have. Third, what level of satisfaction and safety satisfaction based on figured out motive and expectation will participant have. Fourth, what level of revisit based on satisfaction will have. The study is needed for these low items. Therefore, this investigation started as an exploratory study for a successful event to analysis the relationship among expectation satisfaction, safety satisfaction and revisit. The results indicated that participated motive is positively influenced on expectation. The expectation is positively influenced on safety satisfaction. The satisfaction is positively influenced on revisit. Finally, the safety satisfaction is positively influenced on revisit. The unique characteristics of this study is considered a safety satisfaction as m event safety and as an important factor when terror becomes often these days.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.2
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• pp.103-108
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• 2014

Growing concerns about environmental pollution have led to an increase in the demand for compressed natural gas (CNG) vehicles in recent years. CNG vehicles are equipped with a cylinder valve installed in a high-pressure vessel to control the CNG flow. The cylinder valve must meet high quality safety standards because the pressure vessel stores high-pressure CNG. Therefore, safety evaluation of the cylinder valve is necessary to ensure the safety of CNG vehicles. In this study, fluid-structure interaction analysis for the structural integrity of the cylinder valve were conducted using a commercial finite element analysis code(ANSYS WORKBENCH V14). The CFD analysis was performed using a steady-state technique according to the inlet and outlet pressures in order to predict the pressure distribution. Structural analysis was performed by a static structure technique at the maximum working pressure to evaluate the structural integrity of the cylinder valve. From the results, the safety factor of the valve component is between 1.57 and 21.5.

• Safety and Health at Work
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• v.6 no.3
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• pp.200-205
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• 2015

Background: Construction activity has made considerable breakthroughs in the past two decades on the back of increases in development activities, government policies, and public demand. At the same time, occupational health and safety issues have become a major concern to construction organizations. The unsatisfactory safety performance of the construction industry has always been highlighted since the safety management system is neglected area and not implemented systematically in Indian construction organizations. Due to a lack of enforcement of the applicable legislation, most of the construction organizations are forced to opt for the implementation of Occupational Health Safety Assessment Series (OHSAS) 18001 to improve safety performance. Methods: In order to better understand factors influencing the implementation of OHSAS 18001, an interpretive structural modeling approach has been applied and the factors have been classified using matrice d'impacts croises-multiplication $appliqu{\acute{e}}$ a un classement (MICMAC) analysis. The study proposes the underlying theoretical framework to identify factors and to help management of Indian construction organizations to understand the interaction among factors influencing in implementation of OHSAS 18001. Results: Safety culture, continual improvement, morale of employees, and safety training have been identified as dependent variables. Safety performance, sustainable construction, and conducive working environment have been identified as linkage variables. Management commitment and safety policy have been identified as the driver variables. Conclusion: Management commitment has the maximum driving power and the most influential factor is safety policy, which states clearly the commitment of top management towards occupational safety and health.

• Korean Institute of Interior Design Journal
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• v.25 no.1
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• pp.201-212
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• 2016

This study is a literature study aimed to derive the evaluation factors for the survey of housing satisfaction of the physically handicapped. To attain the objective, the present study compared the influential factors of housing satisfaction for normal people and those for the physically handicapped found in the precedent researches, and analyzed them to draw out the evaluation factors for housing satisfaction of the physically handicapped. And then it drew out sub-factors and elements for the housing satisfaction of the physically handicapped. The evaluation factors for housing satisfaction of the physically handicapped are divided mainly into physical, social-psychological and economic factors. First, physical factor consists of 'functionality (usability)', 'safety', 'convenience', 'comfort', 'aesthetics', 'accessibility (mobility)', 'identifiability (recognition)'. Of them, 'functionality (usability)' factor consists of 3 sub-factors and 8 elements. 'Safety' was subdivided into securing safety and public order/crime prevention. and structural safety, and 7 elements were drawn out from 'safety'. 'Convenience' is sub-categorized into convenient usage and simple operation, and 9 elements were derived. 'Comfort' was classified into 2 sub-factors and 9 elements. 'Aesthetics' was classified into 2 sub-factors and elements. 'Accessibility (mobility)' was divided into 2 sub-factors and elements. 'Identifiability (recognition)' was classified into 2 sub-factors and 5 elements. Second, social-psychological factor includes 'sociality' and 'independence' factor. One sub-factor and one element were drawn from each of both factors. Third, 'economic factor' consists of 'economy'. One sub-factor and elements were drawn out from the factor. It is expected that the 10 evaluation factors, their sub-factors and elements that have been derived from this study can be used as the basic data and/or reference in designing residential space for the physically handicapped and making policy for it after verifying them in following studies. The present study finds itself significance in that the findings here can ultimately improve the housing welfare and life quality of the physically handicapped.

• Journal of Ocean Engineering and Technology
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• v.35 no.5
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• pp.327-335
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• 2021

Microcracks can rapidly grow and develop in high-strength steels used in offshore structures. It is important to render these microcracks harmless to ensure the safety and reliability of offshore structures. Here, the dependence of the aspect ratio (As) of the maximum depth of harmless crack (a_hlm) was evaluated under three different conditions considering the threshold stress intensity factor (Δk_th) and residual stress of offshore structural steel F690. The threshold stress intensity factor and fatigue limit of fatigue crack propagation, dependent on crack dimensions, were evaluated using Ando's equation, which considers the plastic behavior of fatigue and the stress ratio. a_hlm by peening was analyzed using the relationship between Δk_th obtained by Ando's equation and Δk_th obtained by the sum of applied stress and residual stress. The plate specimen had a width 2W = 12 mm and thickness t = 20 mm, and four value of As were considered: 1.0, 0.6, 0.3, and 0.1. The a_hlm was larger as the compressive residual stress distribution increased. Additionally, an increase in the values of As and Δk_th(l) led to a larger a_hlm. With a safety factor (N) of 2.0, the long-term safety and reliability of structures constructed using F690 can be secured with needle peening. It is necessary to apply a more sensitive non-destructive inspection technique as a non-destructive inspection method for crack detection could not be used to observe fatigue cracks that reduced the fatigue limit of smooth specimens by 50% in the three types of residual stresses considered. The usefulness of non-destructive inspection and non-damaging techniques was reviewed based on the relationship between a_hlm, a_NDI (minimum crack depth detectable in non-destructive inspection), a_{cr N} (crack depth that reduces the fatigue limit to 1/N), and As.

• Structural Engineering and Mechanics
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• v.70 no.1
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• pp.33-41
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• 2019

The influence of two parameters on fatigue damage predictions of a variably loaded cantilever beam has been examined. The first parameter is the geometry of the cantilever beam and the weld connecting it to a rear panel. Variables of the geometry examined here include the cantilever length, the weld width on the critical cross-section and the angle of the critical cross-section. The second parameter is the safety factor, as set out by the Eurocode 3 standard. An analytical approach has been used to calculate the stresses at the critical cross-section and standard rainflow counting has been used for the extraction of the load cycles from the load history. The results here suggest that a change in the width and angle of the critical cross-section has a non-linear impact on the fatigue damage. The results also show that the angle of the critical cross-section has the biggest influence on the fatigue damage and can cause the weld to withstand fatigue better. The second parameter, the safety factor, is shown to have a significant effect on the fatigue damage calculation, whereby a slight increase in the endurance safety factor can cause the calculated fatigue damage to increase considerably.