• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1319-1326
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• 2012

This study focuses on the influence of tractive forces on the self-stability of a bicycle. The eigen-value analysis of the self-stability of a passive rider control linear bicycle model can be used to analyze the self-stability. A linear bicycle model with front and rear driving forces is developed. The influence of tractive forces on the self-stability is identified by using the developed model. A nonlinear multi-body bicycle model is used to confirm the results of the linear analysis.

• International Journal of Highway Engineering
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• v.9 no.2 s.32
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• pp.1-11
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• 2007

The rapid growths of economy and automobiles since the 1970's have caused serious traffic jams and environmental disruption in urban areas. To relieve these problems caused by urbanization, there should be considered alternative means of transportation modes. Many developed countries have accepted bicycles as a so called "Green Mode" for environmentally oriented strategies to increase the qualities of urban lives. Korea have also attempted various means to raise bicycle usages. In this research, significant factors affecting bicycle crashes at signalized intersections in urban areas were studied. The model results showed that Poisson regression is the best fit methodology for data modeling and revealed that traffic volume, a number of driveways, configuration of the ground, presence of bicycle path, school, and bus stop, residential area, size of intersection are significant factors affecting the bicycle crashes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.603-604
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• 2011

자전거 운전은 본질적인 불안정한 시스템으로 자전거의 안전한 운전을 위해서는 지속적인 운전자의 상호작용으로 인하여 자전거의 안전성을 확보할 수 있다. 그것은 자전거의 운전이 운전자의 운동과 매우 밀접한 연관이 있다는 것을 알 수 있으며, 현재 자전거의 특성뿐 아니라 운전자의 운전에 대한 연구가 진행되고 있지만 정확한 자전거의 주행 안정성에 대하여 연구는 계속적으로 진행되고 있다. 본 논문에서는 자전거 운전자의 몸무게와 신장과 같은 사람의 인체 정보를 이용하여 적절한 안장 높이와 자전거 바퀴 사이의 거리 및 핸들의 높이를 조절할 수 있는 맞춤형 자전거 관리 시스템을 제시하고자 한다. 또한, 운전자 맞춤형 자전거의 설계는 실제 자전거 운전데이터와 영상데이터를 이용하여 적합한 자전거 모델을 제시하고 추출된 데이터를 통하여 분석된 결과를 제시하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.609-610
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• 2011

최근 친환경 생활이 강조되는 오늘날, 자전거(bicycle) 이용자 수가 급격히 늘어나고 있다. 때문에 2륜 자전거의 무인화 및 다양한 기구학적 재해석과 구조학적 재해석을 시도하고 있으며 공학적으로 활발한 연구가 진행되고 있다. 본 논문은 복잡한 2륜 자전거의 복잡한 동역학 방정식을 분석한 결과 인버터 팬들럼 모델과 유사한 점을 수학적 전개를 통하여 알 수 있었다. 이렇게 근사화된 방정식 모델을 바탕으로 비선형 제어 알고리즘을 통하여 비선형 제어기를 설계하여 2륜 자전거의 주행 안정성에 대한 진행속도와 조향각(steering angle) 제어에 대한 상관관계에 대한 연구를 시뮬레이션을 통하여 결과를 분석하고자 한다. 이러한 분석을 통한 2륜 자전거의 자세제어를 통하여 기타 로봇의 자세제어 및 다양한 시스템에 적용 가능성을 제시하고자 한다.

• Journal of Service Research and Studies
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• v.9 no.4
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• pp.19-40
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• 2019

Mobility as a Service is a service conception to achieve the intelligent transportation system. Its aims to improve the travel experience. In one platform, it connects various transportation modes to offer service and users only need to pay in one time for the whole travel. But the single MaaS platform easily faces the problems such as low user traffic, low retention rate and the access to markets of the this service is still unfound. From the perspective of bicycle-sharing, this research makes the MaaS concept into bicycle-sharing to build a better service model. The bicycle-sharing combine with the MaaS concept is innovative in business model, travel model and service architecture. In addition, this research also tests users' expectations for service model. The research shows that MaaS-based bicycle-sharing could offer flexible and convenient travel experience in the aspects of combined transportation, travel, transfer and payment, and it also makes it possible to make travel services according to need, and sustainable transport.

• Journal of Service Research and Studies
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• v.8 no.4
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• pp.53-75
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• 2018

Bicycle-sharing as a product service system in the sharing economy, its characteristic is that users can go to nearby places by the public bike at any time however they don't need to have their own bicycle. However, the service quality of bicycle-sharing and satisfaction of users continuously decrease with the rapid growth number of bicycle-sharing users in China. Based on the double diamond model and from the perspective of service design, this research studies the service experience of bicycle-sharing of Chinese users, focuses on the potential pain points of Chinese users when using the public bike, and designs the optimum proposal to promote users' satisfaction. According to the research result, the research builds a new concept which can satisfy users' demand for communication, enjoyment and option during the cycling. The experience of new service system of bicycle-sharing makes humanized and subconscious interaction possible.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.45-52
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• 2016

One commercial package for magnetic analysis was used to apply repulsive forces of permanent magnetics to bicycle cushion system. Reliabilities of finite element analysis were acquired by comparing with those of experimental measurements. Equivalent spring stiffnesses corresponding to various sizes of magnetics were implemented into the bicycle dynamic model with three degree of freedom. Input force caused at front and rear wheels due to road unevenness was considered in the dynamic model. Dynamic behaviors were observed in terms of vertical displacements of the rider and the front reach as well as pitching displacement of the mass center when the bicycle ran over half-triangular bump. The methodology suggested in this paper by the finite element analysis and numerical model will be an useful tool for more accurate prediction of cushion design for any vehicle system if magnetic forces are utilized.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.119-125
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• 2012

This paper proposes a model for a chainless power assistor system(PAS) that can provide the required power based upon operational status by designing a chainless electric bicycle that can be substituted for a general chain type bicycle and which is also an environmentally friendly means of transportation. This paper designed a fuzzy control algorithm that can intelligently examine operational status through the stopping force sensor of a chainless intelligently auxiliary power system it and also have the power of an auxiliary power system to be controlled by the vehicle's operational status. This paper designed an intelligent electric bicycle that provides auxiliary power to a general bicycle system relying only upon the stepping force of a human and systems to provide auxiliary power to the intelligent chainless bicycle model designing presented.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.103-112
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• 2021

In recent years, public bicycle systems are widely spread over the world according to the development of ICT technology. Since the public bicycle systems in large cities need to secure both publicity and convenience for citizens, analysis of various their issues from introduction to operation is required. In addition, it is also necessary to prepare for various scenarios for coexistence with the PM business, which is recently in the spotlight as a last mile means and normally managed privately. This paper introduces modeling and simulation for efficient operations of public bicycle systems. In particular, the proposed method was developed in a form that can be easily used in other cities by modeling the general structure and behavior of the public bicycle system, and it was developed to facilitate modification and expansion of the future model with a component-based model configuration. This paper provides a case study of the propose method, which is the public bicycle simulation in Sejong City. The simulation results were derived by applying the data from the public bicycle system of Sejong City, and they were verified with the associated real data of Sejong City. Using the verified model, it is expected that it can be used as a tool to design and analyze various services on the public bicycle systems, which were especially suitable for Sejong City.

• Journal of Internet Computing and Services
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• v.24 no.5
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• pp.107-120
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• 2023

The public bicycle of Seoul, Ttareungyi, was launched at October 2015 to reduce traffic and carbon emissions in downtown Seoul and now, 2023 Oct, the cumulative number of user is upto 4 million and the number of bike is about 43,000 with about 2700 stations. However, super growth of Ttareungyi has caused the several problems, especially demand/supply mismatch, and thus the Seoul citizen has been complained about out of stock. In this point, this study conducted a real time demand forecasting model to prevent stock out bike at stations. To develop the model, the research team gathered the rental·return transaction data of 20,000 bikes in whole 1600 stations for 2019 year and then analyzed bike usage, user behavior, bike stations, and so on. The forecasting model using machine learning is developed to predict the amount of rental/return on each bike station every hour through daily learning with the recent 90 days data with the weather information. The model is validated with MAE and RMSE of bike stations, and tested as a prototype service on the Seoul Bike Management System(Mobile App) for the relocation team of Seoul City.