• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.49-58
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• 2009

Four alternative plans for the bus network in Daejeon metropolitan city, which have different hierarchical structure, were proposed : Alternative 1 represents a bus network without hierarchical structure, and Alternative 2, 3, and 4 represent bus networks with primary, intermediate, and advanced hierarchical structures, respectively. Efficiency of the alternative plans were evaluated based on the evaluation index including travel time cost, waiting time cost, and transition penalty cost. The travel time cost was decreased as the level of hierarchical structure gets higher until it reaches the extremely high level. As the level of hierarchical structure get higher, the waiting time cost significantly decreased while the transition penalty cost increased. Collectively, a bus network with hierarchical structure was shown to be more efficient than without it in the light of total travel cost. For the bus network with hierarchical structure, total travel cost shows a concave curve, which implies that there exists an optimal level of hierarchical structure in a bus network.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.523-534
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• 2016

The purpose of this study is to develope a method for measuring social benefit by mitigating in-vehicle congestion level in intercity buses. Contingent valuation method and Tobit model are adopted for social benefit evaluation method. One thousand passengers were interviewed with 992 obtained valid samples. Tobit models with age, income level, and bus boarding times as explanatory variables are selected to estimate the willingness to pay for the mitigation of intercity bus in-vehicle congestion. Statistically and logically, two models with age or income level as explanatory variables are turned out to be valid. The intercity bus service supply status and usage are examined and the bus users who have willingness-to-pay for the intercity bus in-vehicle congestion mitigation have been identified. In case of the 'no standing' rules implemented to the intercity bus, the annual economic benefit from the service is estimated to be 14.7 billion won.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.59-68
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• 2002

Using 1996 annual observations for 69 bus firms in Seoul, this paper measures firm-level efficiency with data envelopment analysis(DEA) and identifies firm characteristics indicative of differential efficiency in these firms with Tobit regression analysis. The paper then conceptualizes that these firms produce two kinds of output(city/seat bus kilometers or city/seat bus Passengers) using four inputs (labor vehicle, fuel and maintenance). The findings show that, on an average, these firms have only a little input saving potential of 0.9 percent, while not a little output increasing potential of 12.9 percent. On the other hand, it is discovered that these firms operate more efficiently with a lower ratio of maintenance employees to total employees. Furthermore, it appears that both the ratio of seat buses to total buses and average speeds positively affect efficiency in this industry.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.88-97
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• 2010

Recently the more convenient services are provided to people in the city in line with the change of city paradigm and the recent development of ubiquitous. For example, Information on bus arrivals an effective advertisement the combination of high technology and departures through smart-phones. However, in respect of the mobile advertisement, because of difficulties such as the means of transferring the mass storage data or the burden of communication charges. there need means to improve such difficulties. This study has been conducted aiming to overcome such difficulties. This study suggests the strategic differentiation plan through the analysis of the media characteristics such as real time service information when in traveling, U-Bus business model in the category of mobile advertisement, etc. and also the concrete system establishment plan from the operation center via network to the delivery of the advertisement through vehicle terminals. In respect that this study suggests the implications as a practical business model through the fusion of high technology and diverse media. It has great significance.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.9-14
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• 2011

Heavy duty diesel engine has relatively small portion of whole vehicles due to long drive distance and large engine displacement, but largely influences atmosphere environment. City buses changed to CNG (Compressed Natural Gas) bus with Korea-Japan Worldcup. Heavy duty truck and intercity bus, however, were impossible to use CNG because those kinds of vehicles had long drive distance and CNG station was installed mainly at the around of the bus garage of city. Insulation container storing the natural gas as a liquid makes heavy duty truck and intercity bus possible to use the natural gas. Drive using diesel is possible where is hard to recharge the gas. With LNG (Liquefied Natural Gas), the dependence on oil is largely decreased, PM (Particulate Matter) and NOx which is chronic disadvantage of diesel is remarkably reduced and finally $CO_2$, the representative green house gas, is reduced over 10%.

• Safety and Health at Work
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• v.2 no.2
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• pp.169-175
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• 2011

Objectives: The questionnaire of occupational stress index (OSI) has been popular in the workplace, and it has been tailored for bus drivers in Taiwan. Nevertheless, its outcomes for participants are based on self-evaluations, thus validation by their physiological stress biomarker is warranted and this is the main goal of this study. Methods: A cross-sectional study of sixty-three city bus drivers and fifty-four supporting staffs for comparison was conducted. Questionnaire surveys, 24-hour urine cortisol testing, and blood draws for dehydroepiandrosterone-sulfate (DHEA-S) testing were performed. The measured concentrations of these biological measures were logarithmically transformed before the statistical analysis where various scores of stressor factors, moderators, and stress effects of each OSI domain were analyzed by applying multiple linear regression models. Results: For drivers, the elevated 24-hour urine cortisol level was associated with a worker's relationship with their supervisor and any life change events in the most recent 3 months. The DHEA-S level was higher in drivers of younger age as well as drivers with more concerns relating to their salary and bonuses. Non-drivers showed no association between any stressor or satisfaction and urine cortisol and blood DHEA-S levels. Conclusion: Measurements of biomarkers may offer additional stress evaluations with OSI questionnaires for bus drivers. Increased DHEA-S and cortisol levels may result from stressors like income security. Prevention efforts towards occupational stress and life events and health promotional efforts for aged driver were important anti-stress remedies.

• 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 Korean Society of Transportation
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• v.33 no.2
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• pp.170-181
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• 2015

This study explores passengers' travel characteristics at six bus stops on the Seoul Ring Expressway using smart traffic card data. Based on the characteristics, political strategies to improve bus facilities on expressway are suggested. Firstly, among them two bus stops of Guri and Uiwang-Cheonggye have higher transfer rate of passengers, 37.56% and 36.9% of the total intercity (red) bus passengers on the expressway, respectively. Secondly, Uiwang-Cheonggye bus stop has the highest transfer rate, and Guri bus stop has also higher transfer rate and the highest on-and-off passengers. It implies that both bus stops need to be prioritized for improving bus stop facility, access roads, and connection facility between the bi-directional stops. Thirdly, Guri (down) bus stop has relatively longer waiting time for transfer, thus shorter bus headways running the bus stop should be considered. Lastly, most passengers using both stops come to and from Bundang-gu in Geongnam City. Overall, the results of this study would be helpful for transport planners to develop effective bus route policies and bus operation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.617-625
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• 2008

In low-density areas where travel pattern is widely dispersed and travel demand is relatively low, transit operators find it very difficult to provide a reasonable level of service at a reasonable cost. Timed-transfer system or network, if designed properly, can provide a reasonable level of service for passengers using transit systems serving low-density areas. The paper intends to apply a timed-transfer system for bus lines serving Yangsan City area and to assess the effects resulted from the application. The concept of a timed-transfer network/system is briefly described, and the present conditions of bus systems in Yangsan City area are discussed, focusing on the aspects of network type and the related problems. The bus timed-transfer network for the area is then developed by adjusting the existing routes and network with the consideration of travel time, route alignments, headways and transfer centers. One must note that developing a timed-transfer network presumes that network and schedule should be developed together. The effects of the developed time-transfer system on the passengers and operators are found substantially so as to justify its introduction to the City. The results of this study will be of considerable use for planners to design the transit systems in low density areas, where in general travel activities are widely dispersed and travel demands are low, so that provision of good quality of transit services are difficult.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.326-329
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• 2010

현재 시행 중인 승용차 RFID 요일제는 제한적인 설치장소와 RFID 설치시 많은 비용이 소비된다. 따라서 본 연구에서는 기존의 RFID 승용차 요일제 방식과 달리 효율성을 높이고 비용을 절감할수 있는 BMS(BUS Management System)를 활용한 버스 RFID system에 관한 방안을 제안한다. 제안하는 방안은 버스 RFID system은 대구시의 시내 버스 뒤편에 양쪽 상단에 RFID 안테나를 설치하여 대구시의 주요 도로를 운행 하며 승용차 요일제를 미준수 여부를 파악하는 것이다. 기존의 고정형 RFID는 설치 위치를 우회 할수 있지만 버스 RFID는 항상 이동하며 감지 하기때문에 차량의 우회에 따른 미확인 경우를 줄일 수 있다. 또한, BMS 활용으로 설치비용을 절감하여 비용대비 효율성을 제고할 수 있을 것으로 예상된다. 구체적인 방안 마련을 위하여 주요도로 버스노선도 파악, 중첩지점 그리고 기존의 승용차 요일제 시스템과 비교 분석을 하여 성능 평가들 실시하는 것에 주안점을 두고 연구를 수행하였다.