• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.7-18
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• 2002

To activate public transportation service, Bucheon City built Bus Information System based on Beacon type, and operates it for no.22 line. This research analyzes an effect of BIS operations, and mainly it analyzes far reliability evaluation of bus arrival time information and passenger satisfaction about BIS. As results of reliability evaluation of arrival time information service, it is proven to be practically inappropriate to use as arrival time data because it is not only travel time between each bus stop but also previous travel time history data. In order to improve this matter, neural network model was evaluated as the most outstanding one as result of experiment in applying current arrival time Prediction model. This research cannot help limiting for evaluation of operation effect in Bucheon City because there is no Bus Information System based on GPS type in Korea. For the future ITS model city, in the case of building ITS model city based on GPS type, it is possible to compare two systems relatively. In addition to that, fur the consideration of reliability of bus arrival time information, it is required to develop Predictable model and research factors that affect to bus operation.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.83-91
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• 2012

In recent days, the study on hybridization of the heavy-duty is going on, actively. Especially, the improvement of fuel economy can be maximized in the intra-city bus because it drives the fixed route. For developing the hybrid electric intra-city bus, optimized control strategy which is possible to be applied with real vehicle is necessary. If the real-time control strategy is developed based on the HILS, it is possible to verify the real-time ability and fail-safety function which has the vehicle stay in safe state when the functional errors are occurred. In this study, the HILS system of series hybrid electric intra-city bus is developed to verify the real time control strategy and the fail-safety functions. The main objective of the paper is to build the HILS system for verifying the control strategy (rule-based control) which is implemented to reflect the Dynamic Programming results and fail-safety functions.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.543-553
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• 2015

This study analyzed that the impact of the bus use environment on users' stress in each step of bus use, from accessing to leaving to transfer, in the city of Daejeon. For this, we collected the stress data from 300 users using personal interviews at the bus stops and on-board bus. Also, we used factor analysis and structural equation model method for analysis of the impact of external and internal bus environments on stress of users. The results of this study showed that the highest stress impact factor was an onboard factor(${\beta}=.416$) including 'density and crowding', 'no seat to seat' and 'low ride comfort and safe'. The next stress impact factor was transfer factor including 'insufficient transfer information', 'lack of connectivity of bus and subway' and 'uncomfort transfer route'. From the above, we recommend that bus policies need to focus on not the supplier but users and also, this user based policy need to be more specified considering the characteristics of various users such as females, the elderly, irregular users, and so on.

• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.44-51
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• 2022

Background: Air pollution is increasing together with industrialization and urbanization. In order to reduce air pollution, public transportation is recommended rather than private cars, and the number of passengers using public transportation is increasing accordingly. This study observes the concentration of indoor pollutants in city buses over time. Through this means, we intend to suggest a plan to manage the indoor air quality in city buses. Objectives: The concentration of indoor pollution in public transportation was investigated from April 2021 to January 2022. Based on this, we evaluated the exposure to indoor pollutants. Methods: Six city bus lines in an industrial city were selected for the research, and indoor pollution was measured through IoT (Internet of Things)-based sensor-type measuring devices. The concentration of pollutants was measured every minute, and statistical data were constructed based on the measurement results. Results: In all the city buses studied, the average concentration of pollutants were below the guidelines. However, some measurement results showed cases of exceeding the guidelines. As a result of the analysis by time zone, there were more cases in which pollutants exceeded the standard value during rush hour compared to at other times. A risk assessment for PM₁₀ was performed by evaluating the excess mortality risk from exposure and the risk from inhalation exposure. Conclusions: All measured indoor pollutants in the city buses did not exceed the guidelines. Also, the risk assessment results were found to be within the level of safety. However, if a city bus is used for a long time, there is a possibility that there may be an impact on the human body due to inhalation exposure, so additional management is required.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.414-417
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• 2001

In this paper the fuel filling system for a city bus was investigated in order to improve the system. The suggested fuel filling system was designed to have functions of identifying a bus arrival tine, and measuring volume of fuel filled. The system consisted of four parts of bus identification, IBM PC, interface card, fuel filling control system and program for integrating all parts. It is believed that the information obtained by this system can be used for analysing driver's driving habits and performance of engine of a bus, and accordingly the prime cost can be reduced.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.89-102
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• 2001

Using a multiproduct translog cost function model, this paper examines the existence or absence of scale and scope economies in Seoul's urban bus industry. The Paper then conceptualizes that the bus firm produces three outputs (city, seat and local bus-kilometers) using low input factors(labor, capital, fuel and maintenance). Using 1996 annual observations for 81 Seoul's bus firms, the equation system consisting of a cost function and three input share equations is estimated with the nonlinear iterative Zellner method. The findings show that the cost function corresponding to a non-homothetic production technology with separability between local bus outputs and inputs adequately represents the structure of cost for Seoul's bus firms, and that the demand lot all input factors is quite inelastic with respect to their own price. On the other hand, nearly all firms experience mild overall economies or scale, but rather marked product-specific economies of scale with respect to all the three outputs. In addition, there appear to be substantial economies or scope associated with the joint production of city and seat bus services, while considerable diseconomies of scope associated with that of city and local bus services. These results indicate that the merger of smaller firms into larger firms with a fleet of approximately 200 buses would result in more cost-efficient bus services.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.1-9
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• 2009

Bus information system(BIS), as a part of the intelligent transportation system(ITS), is one of the most advanced public transportation systems which provide the real-time bus traffic information for the users waiting the buses at the bus stop. However, correct bus information data, such as the present bus location, the user waiting time, the bus arrival time, etc. are not provided for the bus users because the proper bus arrival time predictive models are not used yet in most of the cities operating the bus information system, including the metropolitan City of Ulsan. Thus, the purpose in this study is to investigate real-time bus traffic characteristic data for identifying the bus operation characteristics on the arterial under the study in the metropolitan City of Ulsan, analyze real-time bus traffic characteristic data on the ID locations of the arterial under the study, construct the optimal unit segment models for the unit segments which are the bus stop, node and travel section using the exponential smoothing, weighted smoothing and Kalman Filter methods, respectively, and finally suggest the optimal integrated model for predicting the real-time bus arrival time at the bus stop of the arterial under the study.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.15-24
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• 2011

This study discusses an equity analysis performed to supplement the existing bus service evaluation system. The equity of 179 feeder bus routes in the city of Seoul(Year 2009) is analyzed by employing the modified BCC model along with the desirable inputs such as a number of bus stops and a frequency of operations. In the analysis, each DMU (Decision Making Unit) is assumed to use the desirable inputs, and produces both the index of equity and the index of accessibility. We apply an input-oriented modified BCC model to analyze the equity of the DMUs. The computational result indicates that only 9% of the feeder bus routes are equitable among the total DMUs and the average equity estimate is 0.702. It is also suggested that on average approximately 60% increases of desirable inputs (i.e., a number of bus stops and a frequency of operations) are needed in order to improve equity of DMU in the city of Seoul. The result of the tobit regression analysis on the determinant factors affecting the equity of DMUs shows that all the independent variables (i.e., a number of bus stops and a frequency of operations) are statistically significant at 5% significance level, and the number of bus stops is found to be the most influential factor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2455-2464
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• 2013

This study is focused on the effect of reformation of public transportation system on the efficiency of bus route system as a result of change of government subsidy scheme. Two types of government subsidy scheme has been considered and before and after analysis by Data Envelopment Analysis technique has been carried out for bus routes in Ulsan Metropolitan City. The analysis output has shown that there is no clear evidence to clarify the relationship between the change of government subsidy scheme and the efficiency of bus route system. There are two types of backgrounds may be suggested for this situation such as more longer period necessary to identify the policy effect and limitation to increase the number of passenger in a provincial city. Tobit regression analysis has also been conducted to discover the most effective variables for maximum efficiency and three variables including route length, frequency per vehicle per day, and headway are found to be influential. It is also seen that strategy to minimising input factors and service upgrade plan such as shortened route length and headway, increasing frequency per vehicle are necessary to develop the efficiency of bus routes operated in Ulsan city.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.67-75
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• 2013

The main objective of the research is to analyse the efficiency of bus route operation system which is comprised of Individual Operation System and Joint Operation System. While the reformation of bus route operation system has been usually considered as a service upgrade strategy for inner-city bus operation, it is comparatively difficult to have background information for policy establishment due to shortage of analytical research output. This study adopts Data Envelopment Analysis technique to estimate efficiency of 101 bus routes in Ulsan Metropolitan City which operates two types of operation systems at the same time as of 2009. The analysis results tells that the reason of inefficiency lies on pure technical factor for J.O.G., and scale factor for I.O.G.. It is also confirmed that there is bus route which inefficiently operated in I.O.G and city government needs to prepare the specific plan to upgrade pure technique efficiency before reformation of bus route operation system for successful installation.