• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.655-666
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• 2021

Purpose: This study is to develop a method for measuring dynamic speeding risks using vehicle trajectory big data and to demonstrate the feasibility of the devised speeding index. Method: The speed behaviors of vehicles were analysed in microscopic space and time using individual vehicle trajectories, and then the boundary condition of speeding (i.e., boundary speed) was determined from the standpoint of crash risk. A novel index for measuring the risk exposure of speeding was developed in microscopic space and time with the boundary speed. Result: A validation study was conducted with vehicle-GPS trajectory big data and ground-truth vehicle crash data. As a result of the analysis, it turned out that the index of speeding-risk exposure has a strong explanatory power (R²=0.7) for motorway traffic accidents. This directly indicates that speeding behaviors should be analysed at a microscopic spatiotemporal dimension. Conclusion: The spatial and temporal evolution of vehicle velocity is very variable. It is, hence, expected that the method presented in this study could be efficaciously employed to analyse the causal factors of traffic accidents and the crash risk exposure in microscopic space using mobility trajectory data.

• Korean Journal of Culture and Social Issue
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• v.14 no.2
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• pp.1-19
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• 2008

This research investigated the influences of excessively careful driving as well as chronic disease and medications on dangerousness of traffic accident in elderly drivers. Ninety-one drivers aged 65 years and older participated in the research. To evaluate the driving behavior, we used the self-rating on driving ability questionnaire asking driving speed, the amount of driving and driving situation adaptability' and surveyed the drive career, the number of violations and accidents experience(crash, crashed) for last three years. A review of the driving patterns of elderly drivers showed that the speed and amount of driving were decreased by increasing age. 'Driving- Situational Adaptability (DSA)' consisted of 2 factors such as 'Social Environment(SE)' and 'Physical Environment(PE)'. Elderly drivers reported that their confidence level was lower in PE than in SE. Moreover they had higher difficulty and stress in PE than in SE. DSA of elderly drivers had significant correlations with 'crash' and 'crashed'. This implies that excessively careful driving of elderly drivers directly associated with accidents. Elderly drivers who have nervous system disease or gastritis had more crash accidents. The majority of elderly drivers which take medicine by chronic disease don't think that medications give don't difficulty or inconvenience in driving and constantly drives during a term of taking medicine.

• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.19-28
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• 2006

To develop a crisis management for aviation safety, this study has defined crisis management includes risk management which is eliminates or lowers risks prior to accidents and emergency response after the accidents. This study takes a look at different kinds of crisis managements, risk managements and statistical methods of other nations and fields in order to develop a risk management model. Through surveys which have 102 risk factors that include air traffic control, maintenance and airport sectors, the weight of each risk factor was calculated and the probability was divided to develop a model for risk management. The risk management model of this study is conducted using four steps (risk management plan, risk factor identification, weight and probability analysis, decision making) and 4 standards of weight along with 5 standards of probability This study takes a look at Predictions through a quantitative method using a risk index for the risk management model An effective risk management model should have a wide and continuous collection of data and adopt various methods using this model. The crisis management could not be very effective only using a pre-active risk management. So it should also be conducted by using a pro-active response system to protect additional damage and to prevent accidents of the same nature. From the results, the most important points were the establishment of command and control accountabilities, and cooperation of related organizations.

• Korean Journal of Transplantation
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• v.32 no.4
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• pp.84-91
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• 2018

Background: This study examined the outcomes of ABO incompatible living donor liver transplantation (LDLT). The changes in the immunologic factors that might help predict the long term outcomes were also studied. Methods: Twenty-three patients, who underwent ABO incompatible LDLT from 2010 to 2015, were reviewed retrospectively. The protocol was the same as for ABO compatible LDLT except for the administration of rituximab and plasma exchange. The clinical outcomes and immunologic factors, such as isoagglutinin titer and cluster of differentiation 20+ (CD20+) lymphocyte levels were reviewed. Results: The center showed a 3-year survival of 64% with no case of antibody-mediated rejection. When transplantation-unrelated mortalities (for example, traffic accidents and myocardial infarction) were removed from statistical analysis, the 3-year survival was 77.8%. Although isoagglutinin titers continued to remain at low levels, the CD20+ lymphocyte levels recovered to the pre-Rituximab levels at postoperative one year. Conclusions: As donor shortages continue, ABO incompatible liver transplantation is a feasible method to expand the donor pool. On the other hand, caution is still needed until more long-term outcomes are reported. Because CD20+ lymphocytes are recovered with time, more immunologic studies will be needed in the future.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.100-107
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• 2008

Purpose: A traumatic lung cyst (TLC) is a rare complication and is usually detected with a pulmonary contusion. This study attempted to identify the prognostic factors and the clinical characteristics for pulmonary contusion with TLCs. Methods: We retrospectively reviewed the medical records and chest CT findings of 71 TLC patients who visited our hospital from January 2006 to December 2007. Patients were assessed for any clinical characteristics. We evaluated significant differences between the survival and the death groups for patients with a traumatic lung cyst. Results: The male-to-female ratio of patients with TLCs was 54:17, and the mean age of the patients was $37.70{\pm}19.78years$ with 36.6% of the patients being under 30 years fo age. The cause of blunt thoracic trauma was mainly pedestrian traffic accidents (26.8%) and falls (25.4%). Associated conditions included pulmonary contusion in 68 patients (95.7%), hemopneumothorax in 63 patients (88.7%), and rib fracture in 52 patitents (73.2%). There was no consistent relationship between the number of TLCs and the pulmonary contusion score. The overall mortality rate of TLC patients was 26.8%. Death correlated with a need for ventilatory assistance, mean arterial pressure, worst mean arterial pressure in 24 hours, initial pH and base excess, worst pH and base excess in 24 hours, refractory shock, initial GCS score, and pulmonary contusion score. Conclusion: The presence of the aforementioned predictors indicate serious injury, which is the main determinant of the outcome for thoracic injuries with TLCs.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.39-45
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• 2012

More than 80 percent of traffic accidents related with lane departure believed to be the result of crossing the lane due to either negligence or drowsiness of the driver. Lane-departure related accident in the highway usually involve high fatality. Even though LDWS is believed to prevent accident 25% and reduce fatalities by 15% respectively, its effectiveness in performance is yet to be confirmed in many aspects. In this study, the vehicle lateral locations relative to warning zone envelop (earliest and latest warning zone) defined in ISO standard, ECE and NHTSA regulations are compared with respect to various factors including delays, vehicle speed and vehicle heading angle with respect to the lane. Since LDWS is designed to be activated at the speed over 60 km/h, vehicle speed range for the study is set to be from 60 to 100 km/h. The vehicle heading angle (yaw angle) is set to be up to 5 degree away from the lane (abrupt lane change) considering standard for lane change test using double lane-change test specification. The TLC is calculated using factors like vehicle speed, yaw angle and reaction time. In addition, the effect of vehicle type has been considered to assess LDWS safety.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.231-240
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• 2010

As majority of the traffic accidents in intersections is caused by human factor, a close examination is required on its contributing factors through measuring the psychological and physiological response according to the driving characteristics of the drivers and the road conditions. In this study, for the safety evaluation of individual intersection considering human factors of the drivers, electroencephalography reaction was measured utilizing cutting-edge measuring equipment and survey on drivers' cognitive characteristics in ordinary times and while driving test was conducted. The relationship between the electroencephalography response when approaching the intersection and cognitive evaluation survey data in driving test was clarified, and individual intersection safety evaluation model was built considering cognitive evaluation factor and the reaction of a bio-response electroencephalography data. As a result, I could find out that cognitive evaluation was made through the reaction of a bio-response (Electroencephalography) process because electroencephalography reaction of a bio-response showed differently by the physical characteristics of the intersection and cognitive evaluation had a difference.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.73-84
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• 2005

Highway design criteria are considering roadway safety and smooth driving maneuver. However, a certain highway alignment within design criteria often leads drivers to undesirable situation due to the differences between the original intention of design criteria and the unintended result of drivers' cognition. The differences between them often result in traffic accidents. In order to reduce accident process, highway safety facilities are installed on those roadway sections. However, the relationship between highway environments and human factors has not been deeply studied in Korea. In this study. vertical roadway sections are constructed with 3-D graphical tools. This vertical roadway sections are simulated on a driving simulator in order to identify the differences of drivers' cognition on different roadway environments. Based upon the collected data from the driving simulator, canonical correlation analysis and canonical discriminant analysis of quantification theory II have been performed in order to figure out impacting factors on the degree of roadway safety. Also, based upon quantification theory I. the relationship between roadway safety facilities and the degree of safety has been analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.583-595
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• 2014

Currently, Korean transportation policies are aiming for increase of safety and environment-friendly and efficient operation, by avoiding construction and expansion of roads, and upgrading road alignments and facilities. This is revealed by that there have been 22 road expansion projects (30%) and 50 road improvement projects (70%) under the 3rd Five-Year Plan for National Highways ('11~'15), while there were 53 road expansion projects (71%) and 22 road improvement projects (29%) under the 2nd Five-Year Plan for National Highways. For more effective road improvement projects, there is a need of choosing projects after an objective and scientific safety assessment of each road, and assessing safety improvement depending on projects. This study is intended to develop a model for this road safety analysis and assessment. The major objective of this study is creating a road safety analysis and assessment model appropriate for Korean society, based on the HSM (Highway Safety Manual) of the U.S. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. The collected data was processed correlation analysis of each road element was implemented to see which factor had a big effect on traffic accidents. On the basis of these results, then, an accident model was established as a negative binomial regression model.Using the developed model, an Crash Modification Factor (CMF) which determines accident frequency changes depending on safety performance function (SPF) predicting the number of accident occurrence through traffic volume and road section expansion, road geometric structure and traffic properties, was extracted.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.348-356
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• 2015

In 2026, in ten years from now, Korea is expected to enter into a super aged society. By facing this social phenomenon, analyzing the elderlies and preparing measures are needed among society. In the transportation field, the traffic accidents which are related to the elderly pedestrians have drastically increased so that R&D projects and policy supplementations are introduced. However very few base studies on which focused on the behavior, capability, impact factors analysis of for elderly pedestrians are conducted. To determine the walking capability, this study divided the walking capability into 3 three categories - general, health and exercise. It carries out the comprehensive survey targeting 52 elderlies with the average age of 72.6 years and this survey is made up of total 12 factors in the 3 three categories. This survey also is conducted with various measuring devices and methods such as interview, National Fitness Award, SPBB, Cybex and the like for. From the 12 detailed factors, the general factors such as age, physical shape and so forth have little impact on the walking speed. However the factors that have the greatest impact on the walking speed are extensor muscle on lower limbs in the health factors and balance, coordination, and SPPB in the exercise factors. With these results, this study develops the independent walking model which can measure the walking capability of the elderly people. The developed model is expected to be utilized as the base study for elderly's walking patterns in the transportation field by examining the walking capability of the older people.