• 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.

• 전기의세계
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• v.22 no.1
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• pp.35-41
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• 1973

An automatic point traffic control method is recommended for more idealistic traffic flow over coarse road netowrks. The automatic control apparatus recommended, consists of a transceiver, amplifier, digital-to-analog converter, signal light controller for emergency and steady state, and digital counter as monitor. The transmitter sends a signal to the target vy means of Microwave-FM-CW and a diode detector picks up the echo signal. Thus the operation of the entire system will be carried out through an open loop state. Some factors necessary for an ideal detector system are rapid response, longevity and stability. An analytical method of the Doppler effect substitutes the conventional frequency deviation into the amplitude of detector output. The changing rate of amplitude is proportional to the voltage of the detector output. Some induced formula from Maxwell's radiation field theory ensures this new method, and, new method, and proves the fact with an experimental data presentation. Stability depends upon Klystron as an oscillator and a diode as a detector. the transceiver installation affects on the response and sensitivity of the system. In accordance with the detector output, several targets are easily classified by amplitudes on the scope. The traffic flow, i.e., target movement which is analyzed by the amplitude method, is shown through the scope and indicates it on the digital counter. The best efficiency for the amplitude analysis can be attained through use of an antenna having the highest sensitivity.

• Journal of Korean Society of Steel Construction
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• v.22 no.3
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• pp.209-218
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• 2010

The fatigue phenomenon, which is induced by stress accumulation due to the repeated loading of vehicles in the long term, is one of the main factors of the span of life of a steel bridge. In this paper, the effects of traffic properties on the fatigue life of ordinary short- and medium-span steel plate girder bridges that are exposed to relatively large dynamic effects are investigated. From the analysis, it was known that the fatigue life of the bridge becomes shorter with increasing traffic volume and number of large vehicles, and is affected by the weights of the vehicles. Based on the analysis results, a new parameter that can represent the traffic property that affects the fatigue life of the subject bridge is suggested, and the validity of the parameter is confirmed.

• Smart Structures and Systems
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• v.20 no.2
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• pp.231-246
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• 2017

A recent work by the authors has demonstrated the feasibility of scour evaluation for Kao-Ping-Hsi Cable-Stayed Bridge simply based on ambient vibration measurements. To further attain the goal of scour monitoring, a key challenge comes from the interference of several environmental factors that may also significantly alter the pier frequencies without the change of scour depth. Consequently, this study attempts to investigate the variation in certain modal frequencies of this bridge induced by several environmental factors. Four sets of pier vibration measurements were taken either during the season of plum rains, under regular summer days without rain, or in a period of typhoon. These signals are analyzed with the stochastic subspace identification and empirical mode decomposition techniques. The variations of the identified modal frequencies are then compared with those of the corresponding traffic load, air temperature, and water level. Comparison of the analyzed results elucidates that both the traffic load and the environmental temperature are negatively correlated with the bridge frequencies. However, the traffic load is clearly a more dominant factor to alternate the identified bridge deck frequency than the environmental temperature. The pier modes are also influenced by the passing traffic on the bridge deck, even though with a weaker correlation. In addition, the variation of air temperature follows a similar tendency as that of the passing traffic, but its effect on changing the bridge frequencies is obviously not as significant. As for the effect from the alternation of water level, it is observed that the frequency baselines of the pier modes may positively correlate with the water level during the seasons of plum rains and typhoon.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.295-302
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• 2018

Since the history of the South Korea roundabouts is short, there is a possibility that drivers' awareness for the roundabouts (rules of the road, definition, location, etc.) is low, which may affect the compliance with traffic rules. Based on this assumption, the objective of this study is to analyze the relationship between the awareness and the compliance of traffic rules for roundabouts using a structural equation modeling (SEM). To carry out this objective, an online survey was conducted for 526 drivers, who reside in Goyang, Korea, and an SEM was estimated based on the survey data. As a result, it is concluded that awareness of roundabout has a positive impact on the compliance of traffic rules. Additionally, the compliance is found to show a positive relationship with driving experience. Based on the analysis results, an affective approach through soft measures such as awareness campaigns and educations is recommended to effectively address and mitigate the negative issues induced by roundabouts.

• Wind and Structures
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• v.32 no.5
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• pp.453-469
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• 2021

Snow accumulation on the road frequently induces a big traffic problem in the cold snowy region. Accurate prediction on snow distribution is fundamental for solving drifting snow disasters on roads. The present study adopts the transient method to simulate the wind-induced snow distribution on embankment based on the mixture multiphase model and dynamic mesh technique. The simulation and field measurement are compared to confirm the applicability of the simulation. Furthermore, the process of snow accumulation is revealed. The effects of friction velocity and snow concentration on snow accumulation are analyzed to clarify its mechanism. The results show that the simulation agrees well with the field measurement in trends. Moreover, the snow accumulation on the embankment can be approximately divided into three stages with time, the snow firstly deposited on the windward side, then, accumulation occurs on the leeward side which induced by the wake vortex, finally, the snow distribution reaches an equilibrium state with the slope of approximately 7°. The friction velocity and duration have a significant influence on the snow accumulation, and the vortex scale directly affected the snow deposition range on the embankment leeward side.

• Geomechanics and Engineering
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• v.24 no.2
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• pp.143-156
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• 2021

Rail transit lines usually pass through many complicated topographies in mountain areas. The influence of inclined bedrock on the train-induced soil vibration response was investigated. Model tests were conducted to comparatively analyze the vibration attenuation under inclined bedrock and horizontal bedrock conditions. A three-dimension numerical model was built to make parameter analysis. The results show that under the horizontal bedrock condition, the peak velocity in different directions was almost the same, while it obviously changed under the inclined bedrock condition. Further, the peak velocity under inclined bedrock condition had a larger value. The peak velocity first increased and then decreased with depth, and the trend of the curve of vibration attenuation with depth presented as a quadratic parabola. The terrain conditions had a significant influence on the vibration responses, and the inclined soil surface mainly affected the shallow soil. The influence of the dip angle of bedrock on the peak velocity and vibration attenuation was related to the directions of the ground surface. As the soil thickness increased, the peak velocity decreased, and as it reached 173% of the embedded pile length, the influence of the inclined bedrock could be neglected.

• Journal of Oriental Neuropsychiatry
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• v.34 no.2
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• pp.115-124
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• 2023

Objectives: To report the efficacy of using EFT and Korean medicine treatment for ASD induced by a traffic accident. Methods: We treated ASD symptoms with Korean medicine (acupuncture, cupping, interferential current therapy, herbal acupuncture therapy). To evaluate results of this treatment, Korean version of PTSD Checklist-5 (PCL-5-K), Beck Depression Inventory (BDI), Insomnia Severity Index (ISI), and Numeric rating scale (NRS) at first visit, 5 weeks, and 12 weeks were used. Results: Korean version of PTSD Checklist-5 (PCL-5-K), Beck Depression Inventory (BDI), Insomnia Severity Index (ISI), and Numeric rating scale (NRS) showed improvements after treatments. Conclusions: This study suggests that Korean medicine and EFT treatment might be effective for ASD.

• Journal of Oriental Neuropsychiatry
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• v.34 no.4
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• pp.445-452
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• 2023

Objectives: The purpose of this study is to report the efficacy of using Korean medicine treatment for depression induced by Plica syndrome operation and worsen by a traffic accident. Methods: We treated a patient's depression with Korean medicine treatments (Uwhangchungsimwon, acupuncture, pharmacoacupuncture, cupping, moxibustion, interferential current therapy). To evaluate the results of this treatment, we measured Beck Depression Inventory (BDI), EuroQol-Five Dimensions (EQ-5D), Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: Improvements of BDI, EQ-5D, NRS, ODI and WOMAC were observed after the treatments. Conclusions: This study suggests that Korean medicine treatment for depression may be effective.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4D
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• pp.469-476
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• 2008

Recently, TOD gains popularity as a traffic solution measure of high density urban regeneration projects. The purpose of this study is to investigate traffic impacts of high density TOD projects, and to identify the issues to be resolved. For a case study, it chooses Gangnamgucheong station in Gangnam area served by two subway lines, and designates 400m radius from the station as a site for high-density development. The MOEs chosen for this study is traffic volume, time, distance, speed, and mode share. The SECOM model is adopted for traffic simulation. The analysis results show that high-density TOD is an effective tool for traffic improvement even with only one station area being implemented. It is found that the traffic volume increases near the station in nature where high-density development occurs, but it declines overall in the rest of Gangam area. The total travel time and distance of passenger vehicles decline, meaning that the traffic condition becomes better than before. With regulation on parking supply, the improvement becomes more vivid. In terms of the changes of traffic speed, both alternatives show 4.1% increase in speed, but the difference between alternatives is not quite noticeable because of the induced vehicle demand driven to the streets with improved traffic condition. The mode share changes occur for the benefit of subway ridership, because the study station is equipped with two subway line services. When mixed with parking supply restriction, the impact becomes clearer.