• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.7
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• pp.548-554
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• 2003

This study alms to investigate the dynamic properties of express buses in the very low frequencies which cause motion sickness Incidence. Since passengers often use express buses for long distance traveling. it is a critical point whether the ride give rise to motion sickness or not. In the study accelerations at the three Points on the floor of the six test vehicles were measured during the driving at constant speeds. By applying the frequency weighting corves suggested in ISO 26.31-1, the Physical quantity of accelerations were changed into the perceptual amount used to judge quantitatively the incidence of motion sickness. Motion sickness dose values were calculated from the frequency weighted time history of acceleration signals, and compared between the vehicles, driving conditions. and the seat positions in the bus. During the 50 minutes' driving on the public road and high ways. the vomiting incidence ratios were seen to range from 0.4 to 0.8 ％. which is equivalent to 2.4 to 4.8 ％ for 5 hours' driving. Unlike the very smooth road conditions considered in this work, motion sickness dose values encountered in real situations are expected to increase.

• Journal of Korean Society for Atmospheric Environment
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• v.26 no.4
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• pp.403-411
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• 2010

Recently, emission tests for heavy-duty vehicles have been conducted by heavy-duty engine dynamometer. But, it contains weaknesses that present inconveniences to install and uninstall engines and limitations to reflect on practical characteristics for vehicle driving. On the other hand, chassis dynamometer test is able to differentiate characteristics of real driving patterns due to the reason that vehicles can be examined by utilizing chassis dynamometer. This study aimed at comparing the characteristic of emitting regulatory substances of urban buses on Heavy-duty chassis dynamometer. The characteristic was analyzed based on vehicle speed by using both domestic and overseas developed heavy-duty vehicle test modes. As a result, this work attempted to investigate possibilities to take advantage of Heavy-duty vehicle test modes as a method to manage emissions from heavy-duty vehicles.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.391-401
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• 2011

The Implementation Semi-Public Management System of Intra-City Bus brings improvements of the position stability, work environment and welfare of the bus drivers. As these benefits prevent drivers' job changes, average age of the drivers increases. Some side effects such as fatality increase after the implementation of the new system are becoming social problems. To minimize such problems, it is necessary to prepare the measurements reflected drivers' age increase and driving characteristics of old drivers to decrease traffic accidents of intra-city buses. The existing measurements are mostly simple policy. To get over such limitations, this study grasped driving characteristics by surveys and driving aptitude test targeting old drivers and non-old drivers who brings about traffic accidents actually. As a result, the characteristics of the old drivers were understood precisely. The measures of decrease of the traffic accidents are suggested by the analysis of the behavior characteristics of the old drivers through the structural equation model.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.73-83
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• 2010

The main objective of this paper is to analyze the factors of a semi-public management system of intra-city bus that influence the decrease of traffic accidents which are caused by intra-city buses and the attitude change of intra-city bus drivers over their driving. The results show that the traffic accidents decreased generally as a result of definition of the progresses and characteristics of traffic accidents of intra-city buses before-and-after the system is implemented and with the passing of time after the system began operations. Second, the factors which influence the decrease of traffic offenses before-and-after semi-public management system of intra-city bus are the decrease of violations, safe driving, and job security. Also, the causes which mostly influence the decrease of traffic accidents are defined. Finally, the changing degrees of driving attitudes before-and-after the system is implemented and the causes of the changes are determined. The effects on the decrease of traffic accidents before-and-after the system is implemented as well as the problems and the solutions over time are the main products of this study.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.25-38
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• 2010

In this study, the real on-road driving data were analyzed to draw the various characteristics related to idling of vehicles. The results revealed that the average idling time of a city bus corresponds to 30.9% of the total daily driving time. Among this, for about 21.6% of the total daily driving time, it is available that an engine can be halted while the vehicle stops. It is a daytime when the portion of time, for which idling stop is available, is peak. Due to idling stop, an increase of turnaround was not found throughout this analysis. When a city bus stops at a traffic right, idling periods were long enough to execute the idling stop, during which an engine halts. Whereas, during the idling time for bus stops, the idling periods were not so long enough to execute idling stop. Deceleration periods among the total turnarounds of a city bus occupies about 24.7%, during which, for about 30%, a deceleration maintains for more than four seconds. Thus, using the energy during deceleration period, which then can be recovered from braking energy, it was also found that a hybrid system can be effectively implemented to a city bus.

• Korean Journal of Community Nutrition
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• v.7 no.2
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• pp.232-244
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• 2002

This study investigated the correlation between health-related habits and the biochemical characteristics of the blood of Korean bus drivers. A total of 178 bus drivers working in the Masan area participated in this study. The general characteristics and health-related habits of the subjects were surveyed using a serf-administered questionnaire. The biochemical date were collected from regular health check-ups done through their workshop health insurance company in lune, 1999. The results were as follows : The average age of the subjects was 38 years, and 44.2% had a driving career of between 10 and 19 years. About 90% of the subjects ate irregularly, and 36% ate. health floods. Their rates of drinking, smoking and exercise were 74.6%, 83.6% and 70.8%, respectively. Their frequency of drinking was significantly increased as the length of their driving career increased (p < 0.001). Their levels of total serum cholesterol, in relation to the length of their driving career was significantly higher in the over 20 year group than in the below 10 year group (p < 0.05). Their systolic blood pressures, according to age, were significantly higher in the 51 to 60 age group than in the other groups (p < 0.05). Their total um cholesterol levels signiscantly increased with increasing age (p < 0.001). Their diastolic blood pressures (p < 0.001) and blood glucose levels (p < 0.05) were significantly higher among the subjects who drinking alcohol almost everyday, than among other subjects. Their systolic blood pressures who significantly increased with increasing frequency of their drinking (p < 0.001). The systolic blood pressure and diastolic blood pressure were positively related to age, the amount of drinking, the frequency of drinking and the obesity index, and negatively related to exercise and the duration of exercise. The hemoglobin was positively related to age, preference for a meat diet and the obesity index. The blood glucose was positively related to the amount of drinking, and the total serum cholesterol was positively related to age, length of driving career, period of smoking and the obesity index. The results of this study indicated that bus drivers need regular exercise, moderation of their drinking and smoking, and control of their body weights so as to prevent chronic diseases.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.213-222
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• 2012

After enforcing 2007 semi-public management system of intra-city bus, Busan city has tried to promote the bus utilization through bus service improvements. As an effort for this, we attempted to clarify the main factors affecting to bus service satisfaction targeting intra-city bus users. In this study, 20 subcategories of intra-city bus service were assorted into 6 factors: Basic Service, Safe Driving, Route Information, Comfort, Cleanliness and Facilities, then the preference for each detailed bus service were analyzed. And the effects for bus service satisfaction were shown under the various conditions according to the general characteristics of intra-city bus users (gender, age), behavioral traffic characteristics (frequency of use, boarding time) and transportation environments (temperature, rainfall). These results would be important basic data for decision-making in bus policy for climate change and establishment of operating plan for bus utilization.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.33-42
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• 2011

The types of the accidents caused by intra-city buses and the changing tendencies of driving attitudes are analyzed before-and-after semi-public management system of intra-city bus system is implemented. On the basis of analysis, the measures on the decrease of traffic accidents are considered and the results are as follows. First, it showed that the traffic accidents decreased generally as a result of definition of the progresses of traffic accidents of intra-city buses before-and-after the system is implemented and with the passing of time after the system was operated. Second, the factors which influence the decrease of traffic offenses before-and-after semi-public management system of intra-city bus are the decease of violation, safe driving duty and the job security. Also the cause which mostly influence to the decrease of traffic accidents is defined. Finally, the measures of decrease of traffic accidents are arranged and proposed as a result of PROXSCAL method.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.17-34
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• 2022

This paper develops a model for dynamic station assignment to optimize the Demand Responsive Transit (DRT) operation. In the process of optimization, we use the bus travel time as a variable for DRT management. In addition, walking time, waiting time, and delay due to detour to take other passengers (detour time) are added as optimization variables and entered for each DRT passenger. Based on a network around Anaheim, California, reserved origins and destinations of passengers are assigned to each demand responsive bus, using K-means clustering. We create a model for selecting the dynamic station and bus route and use Non-dominated Sorting Genetic Algorithm-III to analyze seven scenarios composed combination of the variables. The result of the study concluded that if the DRT operation is optimized for the DRT management, then the bus travel time and waiting time should be considered in the optimization. Moreover, it was concluded that the bus travel time, walking time, and detour time are required for the passenger.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.16-28
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• 2017

In this study, we analyzed the result of new inspection, accidents, penalties, and operation records of the elderly driver's driving aptitude test in the city bus using the Transport Workers Management System and the Digital Tachograph Analysis System(eTAS). As a result of the analysis, the results of the driver aptitude test were similar when compared with the traffic company which has many bus drivers and the well - And it was confirmed that the average number of serious injuries and slight injuries in case of accidents was small. Comparing the number of dangerous driving behaviors per 100 km of driving, the elderly driver of the excellent company showed that the number of dangerous driving behaviors is considerably smaller than other elderly and non - elderly drivers, and that the result of correcting the wrong driving habits.