• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.11-16
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• 2009

Better understanding of in-situ mechanical behavior of pavement foundations is very important to predict long-term effects on the system performance of transport infrastructure. In order to do that, resilient stiffness characterization of geomaterals is needed to properly adopt such mechanistic analysis under both traffic and environmental loadings. In this paper, in situ monitoring data from KHC test road was used to analyze the non-linearity of stress conditions under traffic and moisture loadings. Then, the predicted non-linear response using finite element method with a selected constitutive model of foundation geomaterials are verified with the field data.

• Journal of Oriental Neuropsychiatry
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• v.32 no.1
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• pp.1-11
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• 2021

Objectives: To investigate the prevalence of acute stress disorder (ASD) and post-traumatic stress disorder (PTSD) in patients with traffic injuries. In addition, PTSD patients was classified using 'pattern identification for jing ji and zheng chong'. Methods: Questionnaires such as the primary care PTSD screen for DSM-5(PC-PTSD-5), Korean version of PTSD checklist-5 (PCL-5-K), and the instrument of pattern identification for jing ji and zheng chong were conducted on 195 patients within 3 days to 1 year after traffic accidents. Patients were recruited from six medical institutions. Collected data were used to determine the prevalence of acute stress disorder and post-traumatic stress disorder. Results: On PC-PTSD-5, the prevalence was 39.1% for ASD and 50% for PTSD. On PCL-5-K, the prevalence was 20.4% for ASD and 29.3% for PTSD. Satisfying both PC-PTSD-5 and PCL-5-K, the prevalence was 18.2% for ASD and 25.8% for PTSD. As a result of pattern identification for jing ji and zheng chong, 'weakness of heart and gall bladder type' accounted for the highest proportions in both ASD and PTSD groups. Conclusions: In this study, the prevalence was 39.1% for ASD and 50% for PTSD by PC-PTSD-5. Satisfying both PC-PTSD-5 and PCL-5-K, the prevalence was 18.2% for ASD and 25.8% for PTSD. Further large-scale prospective studies are needed to analyze the prevalence of ASD and PTSD, the rate of progression from ASD to PTSD, and the type of pattern identification.

• Structural Engineering and Mechanics
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• v.17 no.5
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• pp.655-670
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• 2004

This paper aims to evaluate the effect of typhoons on fatigue damage accumulation in steel decks of long-span suspension bridges. The strain-time histories at critical locations of deck sections of long-span bridges during different typhoons passing the bridge area are investigated by using on-line strain data acquired from the structural health monitoring system installed on the bridge. The fatigue damage models based on Miner's Law and Continuum Damage Mechanics (CDM) are applied to calculate the increment of fatigue damage due to the action of a typhoon. Accumulated fatigue damage during the typhoon is also calculated and compared between Miner's Law and the CDM method. It is found that for the Tsing Ma Bridge case, the stress spectrum generated by a typhoon is significantly different than that generated by normal traffic and its histogram shapes can be described approximately as a Rayleigh distribution. The influence of typhoon loading on accumulative fatigue damage is more significant than that due to normal traffic loading. The increment of fatigue damage generated by hourly stress spectrum for the maximum typhoon loading may be much greater than those for normal traffic loading. It is, therefore, concluded that it is necessary to evaluate typhoon induced fatigue damage for the purpose of accurately evaluating accumulative fatigue damage for long-span bridges located within typhoon prone regions.

• Safety and Health at Work
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• v.9 no.4
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• pp.454-461
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• 2018

Background: Working conditions and psychosocial work factors have acquired an important role explaining the well-being and performance of professional drivers, including those working in the field of public transport. This study aimed to examine the association between job strain and the operational performance of public transport drivers and to compare the expositions with psychosocial risk at work of three different types of transport workers: taxi drivers, city bus drivers, and interurban bus drivers. Method: A sample of 780 professional drivers was drawn from three transport companies in Bogota (Colombia). The participants answered the Job Content Questionnaire and a set of sociodemographic and driving performance questions, including age, professional driving experience, work schedules, and accidents and penalties suffered in the last 2 years. Results: Analyses showed significant associations between measures of socio-labor variables and key performance indicators such road traffic accidents and penalties. Furthermore, multiple linear regression analysis contributed to explain significantly suffered accidents from key variables of the Job Demand-Control model, essentially from job strain. In addition, throughout post-hoc analyses, significant differences were found in terms of perceived social support, job strain, and job insecurity. Conclusion: Work stress is an issue that compromises the safety of professional drivers. This research provides evidence supporting a significant effect of job strain on the professional driver's performance. Moreover, the statistically significant differences between taxi drivers, city bus drivers, and interurban bus drivers in their expositions to work-related stress suggest the need for tailored occupational safety interventions on each occupational group.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5334-5337
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• 2013

In this paper, the structure of traffic lights removed the wire for the completion of urban aesthetics is analyzed. The finite element model consists of shell elements from three-dimensional CAD model of actual traffic signal. Traffic light pole, horizontal stand shape, thickness, stiffeners, etc. are considered in this study. Analysis of stress and deformation is performed by applying wind load. When the wind load is applied, the result on traffic signal is analyzed. This study is to perform the basic tasks for improving the design.

• Structural Engineering and Mechanics
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• v.55 no.1
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• pp.111-135
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• 2015

Bridge behavior under passing traffic loads has been studied for the past 50 years. This paper presents how to model congestion on bridges and how the maximum dynamic stress of bridges change during the passing of moving vehicles. Most current research is based on mid-span dynamic effects due to traffic load and most bridge codes define a factor called the dynamic load allowance (DLA), which is applied to the maximum static moment under static loading. This paper presents an algorithm to solve the governing equation of the bridge as well as the equations of motions of two real European trucks with different speeds, simultaneously. It will be shown, considering congestion in eight case studies, the maximum dynamic stress and how far from the mid-span it occurs during the passing of one or two trucks with different speeds. The congestion effect on the maximum dynamic stress of bridges can make a significant difference in the magnitude. By finite difference method, it will be shown that where vehicle speeds are considerably higher, for example in the case of railway bridges which have more than one railway line or in the case of multiple lane highway bridges where congestion is probable, current designing codes may predict dynamic stresses lower than actual stresses; therefore, the consequences of a full length analysis must be used to design safe bridges.

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.295-304
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• 2019

Objectives: The purpose of this case report was to propose Yangshimtang-Gamibang on three patients diagnosed with acute stress disorder. Methods: Yangshimtang-Gamibang was treated on three patients diagnosed with acute stress disorder after experiencing a traffic accident. The effects of Yangshimtang-Gamibang were evaluated through BAI (Beck Anxiety Inventory), NRS (Numerical rating scale), NDI (Neck Disability Index), ODI (Oswestry Disability Index), respectively, and quality of sleep was assessed with total sleep time and number of times waking up during sleep. Results: After the treatment, there was significant decrease in the value of BAI score, a measurement of anxiety, as well as the value of NRS, NDI, ODI, a measure of pain. Also, the sleep quality of three patients improved. Conclusions: The results indicate that Yangshimtang-Gamibang may have an effect on people with acute stress disorder who recently experienced a traffic accident.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.254-264
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• 2019

This study is a descriptive correlation study investigating the effects of stress disorder symptoms, resilience, and social network on post-traumatic growth in traffic accident patients. The participants were 158 traffic accident cases enrolled from five 100-bed hospitals situated in city C. Data were collected from July 1 to August 31, 2018, and analyzed by t-test, ANOVA, Pearson's correlation coefficients, and multiple regression using SPSS / Win23. The explanatory power of post-traumatic growth was determined to be 36.9%, and the factors affecting post-traumatic growth were social network and post-traumatic stress disorder. In addition, social networks completely established the relationship between resilience and post-traumatic growth. Our results confirmed that a wider social network and increased symptoms of post-traumatic stress disorder of the traffic accident patient are associated with higher post-traumatic growth. Therefore, it is necessary to explore approaches that improve the social networks and resilience to help post-traumatic growth of traffic accident patients. Additional research is required through repetitive and long-term observation of the accident victims.

• Journal of People, Plants, and Environment
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• v.24 no.6
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• pp.639-649
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• 2021

Background and objective: Various images from visual display terminals (VDTs) as well as living lighting are important parts of our daily life; thus, properly controlling the lighting environment - that is, illuminance, color temperature and good images from VDTs - can have a substantial effect on improving the mental health and work efficiency in everyday life. We examined electroencephalography (EEG) and heart rate variability (HRV) responses to various lighting conditions in 25 university students as they viewed images of a green landscape or traffic congestion. Methods: EEG was performed in darkness and when the room was illuminated with 10 different light-emitting diode (LED) color temperatures, while the EEG and HRV responses to green landscape or traffic congestion image stimuli were measured in darkness and during room illumination with three different LED color temperatures. Results: We found a significant difference between darkness and high LED illumination (400 lx) at 7 (CZ, F4, FZ, O1, O2, OZ, and T6) of 30 channels, while the alpha wave activity increased during darkness. In the second experiment, the green landscape image stimuli in the 30 lx-2600 K lighting condition elicited theta wave activity on the EEG, whereas the traffic congestion image stimuli under high LED illumination elicited high beta and gamma wave activities. Moreover, the subjects exhibited better stress coping ability and heart rate stability in response to green landscape image stimuli under illuminated conditions, according to their HRV. Conclusion: These results suggest that lower color temperatures and illumination levels alleviate tension, and that viewing green landscape image stimuli at low illumination, or in darkness, is effective for reducing stress. Conversely, high illumination levels and color temperatures are likely to increase tension and stress in response to traffic congestion image stimuli.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.273-278
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• 2002

Modern society is an interaction between many different environments. It is important to the mutual relationships between people and especially between people and the environment. One of the mutual relationships between people and the environment is the traffic system, especially the traffic signals which give priority to pedestrian and traffic flow. Traffic signals for the pedestrian on the crosswalk contribute to a safe road environment for the pedestrian, while the traffic signals for the pedestrian running for the flickering of the green signal causes psychological stress. Therefore, this study investigated whether the walking velocity was influenced by the flickering of the green signal or not. Also, this study investigated whether the walking distance had an effect on the walking velocity of the elderly pedestrian or not. It was proved that the flickering of the green signal and the walking distance influenced the walking velocity and subjective sensitiveness according to the result of this study.