• Journal of the Korean Regional Science Association
• /
• v.38 no.4
• /
• pp.75-91
• /
• 2022

With the recent increase in interest in climate change issues, the use of bicycles is complementing public transportation and attracting attention as one of the eco-friendly means of transportation. Daejeon Metropolitan City has been operating Tashu, a public bicycle, since 2008. This study empirically analyzed the spatial characteristics that affect the use of public bicycles by grasping the current status and characteristics of public bicycles and applying spatial econometrics analysis, an analysis model that considers the spatial dependence of spatial data. In addition, a comparative analysis was performed by deriving the results of analyzing six models in terms of rental, return, peak time, non-peak time, weekday, and weekend based on the spatial error model identified as the optimal spatial econometrics model. The analysis model results showed that significant spatial characteristics differed according to the type of public bicycle use. In general, the use of public bicycles was high in areas with a high proportion of young people, a high number of public transportation users, good access to universities and rivers, and relatively low land use mix, and high proportion of apartments. These results indicated that public bicycles are used for commuting purposes on weekdays and leisure purposes on weekends, and if the convenience of using bicycles is improved, the use of public bicycles can be further increased.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.4
• /
• pp.332-340
• /
• 2013

This paper reports a programming toolkit for implementing localization and navigation of a mobile robot both in real world and simulation. Many of the previous function libraries are difficult to use because of their complexity or lack of usability. The proposed toolkit consist of functions for dead reckoning, motion model, measurement model, and operations on directions or heading angles. The dead reckoning and motion model deals with differential drive robot and bicycle type robot driven by front wheel or rear wheel. The functions can be used for navigation in both real environment and simulation. To prove the feasibility of the toolkit, simulation results are shown along with the results in real environment. It is expected the proposed toolkit is used for test of algorithms for mobile robot navigation such as localization, map building, and obstacle avoidance.

• Journal of Environmental Policy
• /
• v.12 no.4
• /
• pp.45-69
• /
• 2013

This study estimates baseline greenhouse gas emissions from transport sector when a new town is developed. It has adopted a general greenhouse gas estimation model developed by Schipper, celine, Roger(2000) for the estimation, and showed how various transport related statistics can be utilized in detail. Particularly, it has produced unit greenhouse gas emission factor per vehicle types, vehicle-km, and trip-km. To evaluate effects of greenhouse gas reduction policies, it has calculated how much emissions will be reduced from bicycle promotion. It has turned out that about 369 thousand tons of carbon dioxide will be emitted from transport sector once the 1st Geomdan New Town is developed in Incheon metropolitan city. If the policy of bicycle promotion can attract people to use bicycle as much as 5% of total trips, then it can reduce about 1,869 tons of carbon dioxide.

• Journal of the Korea Convergence Society
• /
• v.9 no.11
• /
• pp.271-276
• /
• 2018

When the driver riding in a bicycle goes on board, the load of driver is shown differently according to the position loaded on the frame of bicycle. The load is applied most at the joint of bike frame and the load at the mid-part of frame is applied least than the other parts. So, the weight of frame is decreased as the part not applied with a lot of load is manufactured into the thin thickness. As the part applied with high load is manufactured into the thick thickness, it can be endured through this load. The configurations of general frame, double butted and triple butted were modelled by using CATIA program. The durabilities of each model due to the load of passenger were investigated by carrying the structural and fatigue analyses. As this study result investigated with the analysis program of ANSYS, the deformation of general frame happened most and that of triple butted became least. These simulation analysis data are intended to be used to design the actual bicycle frame in the most efficient way at design and manufacture.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.1
• /
• pp.139-147
• /
• 2001

In this study a path control scheme of simulation models of various vehicles to evaluate their handling characteristic is developed. Based on the forward target method, path deviation error is estimated and the required steering effort to reduce the error is computed by Ziegler-Nichols PID control rule. Velocity control model is also included in the proposed path control scheme to achieve the desired velocity. The path control scheme is implemented on a full vehicle model to perform ISO test procedures, such as steady state cornering, lane change, and sinusoidal input, etc. Through the simulations of ISO test procedures and comparison with actual tests, effectiveness and validity of the path control model is demonstrated.

• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.565-570
• /
• 2001

Vehicle dynamics control (VDC) system requires more information on driving conditions compared with ABS and/or TCS. In order to develop the VDC system, tire slip angles, vehicle side-slip angle, and vehicle lateral velocity as well as road friction coefficient are needed. Since there are not any cheap and reliable sensors, recent researches on parameter estimation have given rise to a number of parameter estimation techniques. This paper presents new vehicle model to estimate vehicle's yaw rate. This model is improved from the conventional 2 degrees of freedom vehicle model, so-called bicycle model, taking nonlinear effects into account. These nonlinear effects are: (i) tyre nonlinearity; (ii) lateral load transfer during cornering; (iii) variable gear ratio with respect to vehicle velocity. Estimation results are validated with the experimental results.

• Journal of Korean Society of Transportation
• /
• v.28 no.3
• /
• pp.145-155
• /
• 2010

As the green transportation mode, revitalization of bike usage attracts remarkable public attention. For the acquirement of effective outcome, however, the concrete and close analysis about bike utilization characteristics should be arranged first. One result by MLTM(2009) is support this opinion; the bike mode share has been decreased whereas 9,170km of the bicycle path was improved(1995~2007). This study analyzed the bike mode share classified by trip types by using the 303,308 data of Household Travel Survey of Seoul Metropolitan Area, 2006. The highest mode share rate was induced by the institute attendee and Officetel resident as 3.75% and 3.13%, respectively. Also this study established the bike mode share estimation model of Seoul by logistic regression, and analyzed related factors and level of effectiveness related bike demand by calculation of odds ratio in terms of logistic regression coefficients. In conclusion, short trips, institutes district, parks, and Officetel residential area oriented policy should be effective on the revitalization of bike usage.

• Journal of Korean Society of Transportation
• /
• v.33 no.2
• /
• pp.125-135
• /
• 2015

In this study our main focus is to verify the relationship between social value of transportation system and its perceived features. To achieve this objective, we investigated the value of public bike system (PBS) through willingness to pay (WTP) analysis using contingent valuation method (CVM) and the survey was conducted for 1726 respondents who live in Suwon, Korea. Moreover the determinants related to features related to bicycle use were also gathered. The estimated binary logistic regression and censored regression reveal that the value of PBS is influenced by perceived features towards bicycle use incorporating non-congestion, transportation mode like auto and bus, and high mobility system as well as other variables such as income, bicycle ownership etc. Furthermore the results show that the perceiving of positive features to bicycle use leads to higher social value of PBS. Based on the findings, we discuss the importance of pre-review for transport policy implementation, and also explore the possibilities for application to PBS.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.20 no.1
• /
• pp.10-21
• /
• 2021

This study analyzed how external variables, such as the supply policy of shared bicycles and the spread of infectious diseases, affect the demand for shared bicycle use in the COVID-19 era. In addition, this paper presents a methodology for more accurate predictions. The Seasonal Auto-Regulatory Integrated Moving Average with Exogenous stressors methodology was applied to capture the effects of exogenous variables on existing time series models. The exogenous variables that affected the future demand for shared bicycles, such as COVID-19 and the supply of public bicycles, were statistically significant. As a result, from the supply volume and COVID-19 outbreak according to the scenario, it was estimated that approximately 46,000 shared bicycles would be supplied by 2022, and the COVID-19 cases would continue to be at the current level. In addition, approximately 32 million and 45 million units per year will be needed in 2021 and 2024, respectively.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.3
• /
• pp.123-129
• /
• 2002

This paper proposes a vehicle trajectory prediction method far application to vehicle-to-vehicle distance control. This method is based on 2-dimensional kinematics and a Kalman filter has been used to estimate acceleration of the object vehicle. The simulation results using the proposed control method show that the relative distance characteristics can be improved via the trajectory prediction method compared to the customary intelligent cruise control algorithm.