• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.842-847
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• 2002

One of the challenging problems with bicycle simulators is to deal with the inherent unstable bicycle dynamics that is coupled with rider's motion. For the bicycle dynamics calculation and the real time simulation, it is necessary to identify the control inputs from the rider as well as the virtual environments. The six control forces of the Stewart platform-based motion system are used for estimation of the rider's action force, which is one of the important control inputs, but of which the direct measurement is impractical. For the effective estimation of the rider's action force, the dynamics model of the motion system is derived incorporated with both analytical and experimental methods and the sliding mode controller with perturbation estimation is developed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.42-47
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• 2018

This paper describes the dynamical behavior of the bicycle and its nonlinear effect when magnetic repulsive forces are applied to the bicycle cushion system. A finite-element method was used to obtain its reliabilities by comparing the experimental and numerical values and select the proper magnet sizes. The Equivalent spring stiffness values were evaluated in terms of both linear and nonlinear approximations, where the nonlinear effect was specifically investigated for the ride comfort. The corresponding equations of linear and nonlinear motion were derived for the numerical model with three degrees of freedom. Dynamic behaviors were observed when the bicycle ran over a curvilinear road in the form of a sinusoidal curve. The analysis in this paper for the observed nonlinearity of magnetic repulsive forces will be a useful guide to more accurately predict the cushion design for any vehicle system.

• 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.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.107-118
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• 2014

PURPOSES : The purpose of study is to come up with ideas to improve both the use of the public bicycle and the practicality of the public bicycle system as well. METHODS : The study carried out an analysis on factors which would influence user's satisfaction by using a structural equation and then, discussed what the current public bicycle system should do to make improvements of its own. In order to Satisfaction of the public bicycle system("Tashu") in Daejeon city survey was conducted users and was based on statistical analysis SPSS 20 program, structural equation modeling program AMOS 20 was used for analysis. In addition, the reliability and validity of each question was conducted verification, to verify the hypothesis using structural equation model. RESULTS : According to the results of the analysis with the structural equation used, the connectivity, the convenience, the economic efficiency and the reliability in order were observed to have an influence on the satisfaction of the users CONCLUSIONS : The connectivity turned out to be a factor that would have the greatest concern with the satisfaction of the users. This finding was, therefore, interpreted that people who would ride the public bicycles understand them as more of a transit system that would take them, the people themselves, to another transfer rather than as some immediate transit system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.3
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• pp.122-129
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• 2012

This study investigates structural and vibration analyses according to the thickness of bicycle frame tube. The model of bicycle frame has the dimension as length of 862mm, width of 100mm and hight of 402.5mm. There are 3 kinds of models with tubes of top, down and seat at bicycle frame as thicknesses of 10, 15 and 20mm. The maximum displacement and stress occur at the center part of seat stay and at the installation part of rear wheel respectively. Maximum displacements become 0.031936, 0.029159 and 0.027984mm in cases of thicknesses of 10, 15 and 20mm respectively. In case of thickness of 20mm among 3 cases, maximum displacement becomes lowest. But maximum stresses become 10.019, 8.5492 and 9.2511MPa in cases of thicknesses of 10, 15 and 20mm respectively. In case of thickness of 15mm among 3 cases, maximum stress becomes lowest. There is no resonance at practical driving conditions and natural frequency remains almost unchanged along the change of thickness. In case of the displacement due to vibration mode, the displacement difference at thickness between 15mm and 20mm becomes 1/2 times than that between 10mm and 15mm. Design at bicycle frame tube becomes most economical and durable effectively in case of thickness of 15mm among 3 cases.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.26-40
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• 2018

The aim of this research is to analyze factors affecting bicycle accidents using the PLS structural equation. Accident types in this study were categorized into total accidents, serious injuries including death, and light injuries which occurred at nationwide Si Gun Gu. It was found that urbanization was the main factor for bicycle accidents through the accident models developed in this study. Population, ratio of economically active population, density of intersections, ratio of urbanized area, commercial and industrial land-uses, number of drive license holders, number of education institutions, number of parks were the main factors causing bicycle accidents. Besides, length of bicycle roads, number of bicycles, and ratio of bicycle as mode choice also increased bicycle accidents.

• 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.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.17-30
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• 2009

Recently, Interest in the riding of bicycles increased, but existing researches on the effect of bicycle facilities and the supply analysis and evaluation bike analysis of the importance of the item is most fulfilling. Those do not reflect characteristics of the region and the current satisfaction on the riding of bicycles. Therefore, this research will classify Gu Dong of Busan into good region, possible region and difficult region on the riding of bicycles to reflect characteristics of bicycles with the non-power and characteristics of riders with the main purpose of the exercise. Maintenance of bicycles classified according to the region will be decided to the Line-to-Line maintenance as to connect the main point of regions and to the Point-to-Point as to link the main point within region. Then, step-by-step bicycles activation of Busan differentiated by region offers. Also, Survey on Gangseo-Gu, Sasang-Gu, Gijang-Gun with good bicycle conditions and Busan-Jin-Gu with the best maintenance effect will be about the bicycle. The structure model of consciousness-based on the use of bicycles will be made by using Survey results and considering the region characteristics. This structure model will show a correlation of the current satisfaction, the bicycle-related facilities maintenance policy needs, region characteristics and the next intends to riding the bicycle.

• 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 Korean Society for Quality Management
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• v.46 no.3
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• pp.523-538
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• 2018

Purpose: The purpose of this study was to propose useful suggestions by analyzing causal effect relationship between sharing bicycle service quality, customer satisfaction, CSV, and continuos use intention in China. Methods: The collected data through the survey were analyzed using structure equation model analysis. The measurement tools used for this study were divided into four dimensions such as service quality, customer satisfaction, creating shared value, and continuous use intention. Results: The results of this study are as follows; regarding the influence of sharing bicycle service quality dimension on customer satisfaction(reliability and response), it was found that customer satisfaction was not significant on economic value. but it was significant on social value. It was found that social value made statistically significant influence on use intention. Conclusion: Sharing bicycle industry needs to activity of response to customer, and paying attention to view of social value for the sharing economy in the future.