• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.8
• /
• pp.582-594
• /
• 2016

Most studies on hybrid buses are on large-sized buses and not mid-sized low-floor buses. This study uses MATLAB simulation to evaluate the fuel efficiency of such buses powered by diesel. Based on the results, a hybrid electric vehicle system is recommended for the best combination of power and gear ratio. A parallel hybrid system was selected for the hybridization, which transmits front and rear wheel power independently. The necessary power to satisfy the target performance was calculated, and the applicable capacity area was designed. Dynamic programing was used to create and optimize a component sizing algorithm, which was used to scale the capacity of each component of the power source to satisfy the design criteria. The fuel efficiency rate, optimum power source capacity, and gear ratio can be improved by converting a conventional bus into a parallel hybrid bus.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.1
• /
• pp.88-93
• /
• 2004

In general, a fundamental structural design consideration for an automobile is the overall dynamic behavior in bending and torsion. Dynamic behavior of the automobile are mainly influenced by the structural stiffness of B.I.W.(body-in-white) and the physical property of trim components. In this paper, the modeling techniques for various trim components of middle-sized bus are presented, and the dynamic effects of the trim components on the vibration characteristics of the bus are investigated. The $1^{st}$ torsional frequency is decreased by attaching windshield and backlite to the B.I.W., but the $1^{st}$ vertical bending frequency and the $1^{st}$ lateral bending frequency are increased. The natural frequencies of the bus are decreased by attaching doors and windows. And also, the natural frequencies of the bus are large decreased by attaching seats, instrument panel etc. The study shows that the dynamic characteristics of the bus can be effectively predicted in the initial design stage.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1451-1452
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1453-1454
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1449-1450
• /
• 2010

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.1
• /
• pp.17-30
• /
• 2018

Currently, the global climate change response paradigm has been changed to a universal response system in which all nations, not the developed countries, participate. Korea has also set a target of 25.9 million tons of transportation greenhouse gas reduction targets by 2030. Korean society is expected to enter the super aging society in 2026. In this study, to reduce the greenhouse gas emissions in public transport and to improve the convenience of transportation vulnerable, we estimate the willingness to pay(WTP) and social benefits assuming that the existing feeder buses are replaced with medium-sized low floor electric buses. To this end, survey was conducted on bus users in the metropolitan area and WTP was estimated by using contingent valuation method(CVM), which is one of the non-market value evaluation methods. As a result of estimation of WTP, the average WTP is 51.4 (won / time person), estimated the economic benefits were 50 million won on weekdays and 40 million won on weekends in Gyeonggi Province in 2014.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1455-1456
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.1457-1458
• /
• 2010

• Aerospace Industry
• /
• v.38
• /
• pp.12-19
• /
• 1996

한국중형항공기사업조합(KCDC)이 현판을 내 건지 2년째로 접어들었다. 그러나 정책과제로 입안되어 수년간의 타당성 검토를 거친 사업조합의 가시적 성과는 아직까지 확인되지 않고 있다. 그동안 막대한 기반시설의 투자와 소요된 시간을 생각하면 업계로서는 여간 조급한 일이 아니다. 이즈음에서 우리 업계와 정부 당국은 잠깐 물러서서 조급함을 달래는 여유를 가질 것을 제안하고 싶다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.6
• /
• pp.1309-1320
• /
• 2015

This study made an attempt to analyse the relationship between operation environment and fleet size per route which represents the level of service for inner-city bus service. Regression analysis method has been adopted as main analysis tool and 98 routes of bus operation status in Ulsan city as of 2013 has also been selected for analysis target. Correlation analysis was performed to identify the relationship between dependent and independent variables. There are three types of model for whole sample, type operation, and bus route operation system. These are the results of the current study. 1. The model developed for whole sample of 98 routes is as follows. Y(Fleet Size)=$-4.532+0.00002877*X_1$(Revenue). This model shows that it is necessary to have more than 140 passengers per day to increase fleet size of each bus route in Ulsan. 2. Models developed by type of operation (which are standard, express, and middle sized) are shown below. Stand Bus : Y(Fleet Size)=$-10.954+0.00004283*X_1$(Revenue). It is identified that more than 153 passengers need to use standard bus to increase fleet size per each standard bus, Middle Sized Bus : Y(Fleet Size)=-0.859+0.00001438*X1(Revenue). For middle sized bus, at least 52 daily passengers are needed to increase number of bus in each route. 3. Models developed for each route operation systems are as belows. Joint Operation Group : Y(Fleet Size)=$-4.786+0.00003028*X_1$(Revenue). Individual Operation Group : Y(Fleet Size)=$-2.339+0.00002030*X_1$(Revenue). These model provide similar result which 140 people is the minimum number of passenger to raise the number of vehicles in each route. This result shows that the route operation systems does not affect the raise number of cars significantly.