• Title/Summary/Keyword: The structure of a bicycle

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Utilization of Finite Element Analysis in Design and Performance Evaluation of CFRP Bicycle Frames (유한요소해석을 이용한 CFRP 자전거 프레임의 설계 및 성능 평가)

  • Lee, Yong-Sung;Shin, Ki-Hoon;Cheong, Seong-Kyun;Choi, Ung-Jae;Kim, Young-Keun;Park, Kyung-Rea;Kim, Hong Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.1
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    • pp.121-127
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    • 2013
  • With the continuing demand for lightweight bicycles, carbon fiber composite materials have been widely used in manufacturing bicycle frames and components. Unlike general isotropic materials, the structural characteristics of composite materials are strongly influenced by the staking directions and sequences of composite laminates. Thus, to verify the design process of bicycles manufactured using composites, structural analysis is considered essential. In this study, a carbon-fiber-reinforced plastic (CFRP) bicycle frame was designed and its structural behavior was investigated using finite element analysis (FEA). By measuring the failure indices of the fiber and matrix under various stacking sequences and loading conditions, the effect of the stacking condition of composite laminates on the strength of the bicycle structure was examined. In addition, the structural safety of the bicycle frame can be enhanced by reinforcing weak regions prone to failure using additional composite laminates.

Stabilization of Attitude for Autonomous Bicycle System Using Sliding Mode Control

  • Park, In-Gyu;Ham, Woon-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.173.3-173
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    • 2001
  • In this paper, attitude control of autonomous system using bike based on variable structure control is discussed. Variable structure control is more than a promising technique in the field of nonlinear control. It permits the realization of very robust and simple regulators, with appealing sliding mode characteristics especially if the considered dynamics requires a very short sampling time. We derive dynamic equation of it and demonstrate that the designed controller stabilizes attitude simultaneously regardless of wheel position by computer simulation.

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A Study on the Estimation of the Ownerships of Bicycles by Spatial and Social Factors in Urban Area (도시의 공간적, 사회적 요인에 따른 자전차 보유도 추정에 관한 연구)

  • 김기혁
    • Journal of Korean Society of Transportation
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    • v.12 no.1
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    • pp.85-95
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    • 1994
  • While bicycles are an exhaust-free and low energy consuming mode of transport, the use of them is getting decreased. The aim of this research is to find out current levels of bicycle ownership and to estimate the ownerships of the bicycles by spatial structure and social factors in the metropolitan area. The parameters which affect on the characteristics of the bicycle ownership are classified into aggregate and disaggregate categories. The ownerships of the bicycles are estimated by the multiple regression analysis using urban characteristics data and the binary logit analysis using household characteristics data. The results of this study to population, car ownership, and number of male in the household, and negatively by the population density.

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Parametric design for mechanical structure using knowledge-based system (역학적 구조에 대한 Knowledge-based 시스템을 이용한 파라메트릭 설계)

  • 이창호;김병인;정무영
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.1018-1023
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    • 1993
  • In mechanical structure design area, many FEM (Finite Element Method) packages are used. But the design using FEM packages depends on an iterative trial and error manner and general CAD systems cannot cope with the change of parameters. This paper presents a methodology for building a designing system of a mechanical structure. This system can generate the drawing for a designed structure automatically. It consists of three steps: generation of a structure by selection of the parameters, stress analysis, and generation of a drawing using CAD system. FEM module and parametric CAD module are developed for this system. Inference engine module generates the parameters with a rule base and a model base, and also evaluates the current structure. The parametric design module generates geometric shapes automatically with given dimension. Parametric design is implemented with the artificial intelligent technique. In older to the demonstrate the effectiveness of the developed system, a frame set of bicycle was designed. The system was implemented on an SUN workstation using C language under OpenWindows environment.

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An Evaluation on Bending Behaviors of Conical Composite Tubes for Bicycle Frames (자전거 프레임용 원추형 복합재 튜브의 굽힘 거동 분석)

  • Hwang, Sang-Kyun;Lee, Jung-Woo;Hwang, Hui-Yun
    • Composites Research
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    • v.29 no.6
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    • pp.358-362
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    • 2016
  • Mechanical properties of static and dynamic behavior became important since the use of conical composite tubes in large structures such as aerospace, planes, and submarines as well as leisure goods such as bicycle frames, fishing rods, and golf shafts. In the past, the mechanical property prediction model for static behavior was studied using vibration, bending, and buckling. But there is a need to study how fiber orientation error affects mechanical properties of conical composite structure because the model assumes constant fiber orientation angle. The purpose of this study is to derive an equation that can predict the static behavior of conical composite tube for bicycle frames by considering fiber orientation error with respect to various design parameters.

The Evaluation of the Proposal for Condominium Housing Remodeling in National Housing Scale($85m^2$) (국민주택 규모의 공동주택 리모델링 계획안의 평가)

  • Choi, Jung-Min
    • Korean Institute of Interior Design Journal
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    • v.16 no.3 s.62
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    • pp.119-129
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    • 2007
  • This study illustrates a prototype proposal and its evaluation for the development of floor plans in the condominium housing remodeling. For this I evaluated the survey of the residents of the 'K' town in Joonge-dong, Nowon-gu, Seoul, against the proposal which was developed based on the resident's pre-survey. The result includes that the residents' preference for community actions such as the removal of fences which are reviewed as negative, whereas the introduction of a fitness center and community facilities in the library are reviewed as positive. The residents preferred the open space by the piloti structure, although which is the wall column structure, where they anticipated a rest area, sports facilities, and bicycle drop-off spots. The sidewall proposal in the main building and the full use of the roof floor were underestimated in terms of design concept. The research also illustrated the residents' desired space planning options, those tending to use of space 'B type', personalization 'C type' and spatial size 'A type'. Residents responded positively to the introduction of the 'Alpha' space in which two households share one space that could be used for multiple purposes such as a rest area, an environment-friendly garden, and hobby room, etc, and also there is another possibility it plays an important role to the sociality in community.

A Study on Change of Wild Bird Habitat Characteristics According to Riparian Forest Construction in Yangjae Stream, Seoul (서울 양재천 하천 숲 조성에 의한 야생조류 서식특성 변화 연구)

  • Yun, Suk-Hwan;Han, Bong-Ho;Choi, Jin-Woo;Yun, Ho-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.5
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    • pp.97-110
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    • 2018
  • The purpose of this study is to provide basic data and evidence for the habitat improvement of wild birds in urban stream by analyzing changes in habitat characteristics of wild birds by riparian forest construction in Yangjae stream in Seoul. In Gangnam-gu, the multi layered riparian forest consisting of landscape trees and shrubs was formed on the slope. In Seocho-gu, the vertical vegetation structure of woody and herbaceous wetland plants was good. In Gangnam-gu, the vegetation area of the slope increased and the vertical stratification structure affected the species diversity of the forest birds. The number of species and individuals of plovers, sandpipers and wagtails decreased due to the impact of bicycle roads and trails. The poor forests on the levee slope in Seocho-gu affected the habitat selection and migration of the forest birds. The willows and amur silver-grasses formed in the riverside have been developed into the riparian forest, thus stabilizing the habitat of water birds by blocking disturbances from the influence of the trails.

A Study on Safety Standards of a Railway Crossing (철도 건널목 안전기준에 관한 연구)

  • Jeong, Yeon-Jeong;Lee, Seong-Mo;Park, Chang-Ho
    • Journal of Korean Society of Transportation
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    • v.27 no.1
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    • pp.83-95
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    • 2009
  • The railway crossing is very dangerous because the track intersects with the road there. Thus, The laws were designed for safety of the railway crossing and they are classified as to the acts for the road and the railroad. For safety of the railway crossing, there are 'Road/Railroad Crossing Improvement Promotion Act', 'Enforcement Decree of Road/Railroad Crossing Improvement Promotion Act', 'Rules on Construction of Railroad', 'Rules on Safety Standards of Railroad Installations', and 'Enforcement Ordinance of Cable way/Railway Track Act' in the acts for the railroad and there are 'Road Traffic Act', 'Enforcement Ordinance of The Road Traffic Act', 'Ruled on Structure and Facility Standards of The Road', 'Rules on Structure And Facility Standards Of The Rural Road' and 'Rules on Structure and Facility Standards of The Installations for Bicycle' in the acts for the road. Both the acts for the road and the railroad have standards for the structure of the railway crossing. However, they have different standards. Besides, they don't have standards for new facilities which were recently installed for safety of the railway crossing. Therefore, we suggest new standards for safety of the railway crossing.

Vision-Based Fast Detection System for Tunnel Incidents (컴퓨터 시각을 이용한 고속 터널 유고감지 시스템)

  • Lee, Hee-Sin;Jeong, Sung-Hwan;Lee, Joon-Whoan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.1
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    • pp.9-18
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    • 2010
  • Our country has so large mountain area that the tunnel construction is inevitable and the need of incident detection that provides safe management of tunnels is increasing. In this paper, we suggest a tunnel incident detection system using computer vision techniques, which can detect the incidents in a tunnel and provides the information to the tunnel administrative office in order to help safe tunnel operation. The suggested system enhances the processing speed by using simple processing algorithm such as image subtraction, and ensures the accuracy of the system by focused on the incident detection itself rather than its classification. The system is also cost effective because the video data from 4 cameras can be simultaneously analyzed in a single PC-based system. Our system can be easily extended because the PC-based analyzer can be increased according to the number of cameras in a tunnel. Also our web-based structure is useful to connect the other remotely located tunnel incident systems to obtain interoperability between tunnels. Through the experiments the system has successfully detected the incidents in real time including dropped luggage, stoped car, traffic congestion, man walker or bicycle, smoke or fire, reverse driving, etc.