저탄소 녹색성장 기본법에서 명시한 ‘대중교통과 자전거 이용 활성화’를 위하여, 국내 여러 지자체에서 공공자전거 사업을 시행하였 으며, 자전거 이용자 수가 많이 증가하였다. 현재 국내에서 규정하는 자전거의 통행방식은 간접좌회전(hook turn) 방식으로, 증가된 자 전거교통량이 횡단보도를 통해 좌회전 통행 시 상충 가능성이 증가할 수 있다. 또한 자율주행차량의 혼재교통상황을 고려하여, 자전거 가 차량과 함께 통행할 시 안전성을 보장받을 수 있는지 혼재교통류에 적합한 통행방식을 연구할 필요가 있다. 따라서 본 연구에서는 혼재교통환경에서 자전거 이용자가 안전하고 운영성 높은 방식으로 통행할 수 있도록 4가지 자전거 좌회전 통행방식을 적용하고, 자 율주행차량 점유율에 따른 적합한 통행방식을 제시하고자 한다. Hook-turn 방식을 기본 시나리오로 하여, 자전거 우선 신호를 도입한 bike box, 일반 bike box, 자전거 전용 신호를 도입한 narrow lane 시나리오를 비교하였다. bike box의 크기가 분석 결과에 큰 영향을 미 치는 요인이 될 수 있으므로, 5m 폭의 크기로 고정하였다. 시뮬레이션 환경에서 첨두시와 비 첨두시 교통량을 적용하여 분석하였으며, 안전성 평가지표로 CPI(Crash Potential Index)과 운영성 평가지표로 지체시간(Delay time)을 활용하여 결과를 비교하였다. hook turn시나 리오는 사고 발생 위험도가 작으며, 자전거 전용 신호가 적용된 narrow lane과 일반 bike box에서 사고 발생 위험도가 높게 나타났다. 또한 자전거 전용 신호를 적용한 bike box를 도입한 시나리오에서 운영성 측면에서 지체가 작게 나타났으며, 자율주행차량 점유율이 증가할 시 차간거리를 고려함에 따라 교통류 안전성도 향상되는 것으로 나타났다. 향후 자율주행차량 혼재 교통류를 고려하여 자전거 좌회전 통행방식을 자전거 우선 신호를 적용한 bike box 방식으로 규정한다면, 접근로별 50대 미만/시의 자전거 교통량이 관측되는 신 호교차로에서 안전성과 운영성이 향상되는 효과를 확인할 수 있다.

In this paper, design of a recumbent bicycle for loading cargo is introduced as an application example of practical engineering. This device consists of a main frame due to the main load, an occupant seat considering the human body structural condition, a steering device(handle), a power transmission device (gear/chain, pedal, and crank), and a braking device (disk brake). In order to design and manufacture of the device, various subjects learned during the school year are reviewed and practiced. In particular, by designing the shape considering the load acting on the recumbent and the structural conditions of the human body, it is possible to understand the detailed mechanical mechanism as well as the understanding for the basic design. Through this case study, students can develop and enhance their creativity and practical skills for related industries by designing and manufacturing a real recumbent bike and, if necessary, industrializing these skills.

환경과 교통이슈로 자전거가 대안적 교통수단으로 주목받는 가운데, 많은 나라에서 자전거 이용을 촉진하기 위해 공유경제 플랫폼인 공공자전거 사업을 운영 중이다. 서울시 역시 공공자전거인 “따릉이”를 5년째 운영 중이며, 이제 따릉이는 서울의 단거리 교통수단 중 하나로 자리매김하였다. 이 연구는 따릉이가 몇 가지 문제점을 가지고 있으며 개선이 필요하다고 주장한다. 이 연구는 자전거 흐름의 시공간적 패턴을 파악하고 그 원인을 설명하고자 한다. 이를 위해 따릉이의 요일, 시간대별 이용 패턴을 분석하고, 서울시의 주요 자전거 네트워크 클러스터를 찾는다. 네트워크 클러스터를 찾기 위해서 Getis와 Ord의 Gi통계를 공간 네트워크로 확장 적용하였다. 이후 통계적 유의성을 검증하기 위해 부트스트랩 치환법(Bootstrap permutation)을 사용하였다. 연구결과 서울시 에서 시계열에 영향받지 않는 명확한 자전거 네트워크 클러스터를 확인하였다. 하지만 국지적 분석 결과는 시간대별 통행 방향에 명백한 차이를 보여준다. 이 연구는 따릉이의 효과적, 효율적 운영을 위해서 따릉이 이용 패턴의 시간, 공간적 차이를 측정하고 반영해야 한다고 제안한다.

Cassettes are a key component for power transmission and smooth shifting, and their construction consists of sprockets and spiders. The sprocket receives the force generated by pressing the pedal through the chain and rotates the rear wheel. It is a circular part. As the shifting system for efficient driving of bicycles has been developed, chains and sprockets require more complicated shapes than the conventional ones, and researches are being conducted to increase the production efficiency of sprockets. Cr-Mo steel is mainly used as the material for sprockets, but the trend of converting high-performance cassette material to titanium, which is a material with high specific strength, is gradually increasing. In this study, we also studied the molding technology of titanium material for the 5th and 6th stage shape design, the finite element analysis and the mass production using the press mold.

PURPOSES: Seoul introduced public bicycles to reduce environmental pollution and create a healthy society. Because the use of bicycles is highly weather dependent, and bicycles are rented by the people, member characteristics and seasonal influences should be considered. This study analyzed bicycle traffic characteristics considering seasonal and member characteristics and highlighted some implications. METHODS: The Yeouido and Sangam districts, which have multiple business districts, were taken as the areas of interest. In order to reflect seasonal and membership characteristics, the traffic volume, time of use, and characteristics of each zone were categorized by season (spring, summer, autumn, winter) and membership type (season, daily, group). In addition, we analyzed the pattern of traffic volume and usage time according to the traffic purpose after separating rental locations into residential, business, subway, and park, reflecting the land characteristics. RESULTS: The results revealed that seasonal characteristics were high for bicycle traffic, time of use, and occupancy rate for park locations in spring and autumn. In terms of membership characteristics, group and daily users appeared as major visitors for park locations, and the trends of commuter pass users showed that bicycle use meets the purpose of introducing public bicycles. CONCLUSIONS: Traffic characteristics differed according to seasonal and membership characteristics. It is necessary to involve and extend the users of the commuter pass. Situations in which commuter pass users cannot function as a group or in which daily users monopolize bicycles (especially near parks, near subway stations, etc.) must be avoided.

PURPOSES : The objective of this study is to develop a methodology to estimate the minimum required separation distance (MRSD) between a vehicle and a bicycle when overtaking.METHODS: Three steps have been conducted to develop a methodology to estimate MSRD. First, a literature review has been conducted on the measurement of MSRD, and how it may be applied in Korea. Second, two assumptions have been made to develop a methodology to estimate the MSRD. The first assumption is that the maximum separation distance between a vehicle and a bicycle can be observed when they are at the same location longitudinally. In addition, it is assumed that the separation distance is invalid when the contra-flow exists. Finally, three cameras were installed at a height of 10 m to record the vehicle-bicycle interaction. Moreover, the vehicle trajectories as well as the separation distance were coded and analyzed. Through the hypothesis test and the interval estimation, the sample mean was tested and the confidence interval was estimated.RESULTS : 141 records of separation distance data were collected, and the hypothesis test demonstrated that the MSRD in Korea is significantly higher than other countries. In addition, the confidence interval of the population mean of MSRD is from 1.51 m to 1.65 m with 95% level of confidence.CONCLUSIONS: It is expected that the proposed methodology to estimate MSRD would be beneficial in studying road safety of vehicles and bicycles. Also, the proposed MSRD is expected to be designated in the act of road and transportation.

The stiffness of a bicycle frame is a major factor of a bicycle performance related to safety, stability, and weight. In this study, the torsional and bottom bracket stiffness of a bicycle frame were experimentally investigated. The torsional and bottom bracket stiffness for 63 bicycle frames were evaluated and analyzed by measuring the displacement of frames. The torsional stiffness is related with turning performance and the bottom bracket stiffness is related with power transmission. The experimental results show that the average stiffness varies up to 20 % according to the frame materials and types. The torsional stiffness has a strong corelation with the bottom bracket stiffness even though they have different effects on a bicycle frame. It seems that the experimental results can be applied to the quality criteria of racing bicycles and also design standard of a bicycle frame.

자전거의 안장 지주에 영구자석의 척력을 이용하여 완충장치를 설치하고자 자기 해석용 상용프로그램을 이용하였다. 유한요소법으로 구한 해석치를 실험치와 비교하여 유한요소 해석치의 신뢰성을 확보하였다. 그 후에 3 자유도계의 자전거 동역학 모델을 완성하고 자석의 크기에 상응하는 등가 스프링 강성값을 모델에 이식하였다. 자전거의 동역학 모델에서 전륜과 후륜은 주행면의 비평탄도에 의한 입력을 부담하도록 하였다. 전륜과 후륜이 독립적으로, 또는 동시에 반삼각 범프(halftriangular bump)와 정현파 굴곡로(sinusoidal road)를 통과할 때의 동적 거동을 살펴보았다. 운전자와 프레임의 수직거동, 주행방향의 피칭 거동을 관찰하였으며 자전거의 완충 시스템을 보다 구체화할 수 있는 기반을 마련하였다.

The bicycle road network in South Korea has increased from 4908 to 18281km between 2006 and 2013. Pervious concrete, as a typical bicycle pavement, allows rainwater to seep through the surface instead of running off. However, due to the low binder content and low water-cement ratio of pervious concrete, it is susceptible to durability problems such ravelling due to abrasion and freeze-thaw failure. This research aims to develop a pervious concrete mix which will obtain sufficient permeability, strength and durability. In this research, four types of mixtures were investigated with varying fine aggregate and admixture content. The physico-mechanical properties of the pervious concrete were investigated including strength, void ratio, permeability, abrasion and freezing-thawing durability of the concrete mixtures. Furthermore, time delay for placement was investigated. Results imply that the fine aggregate content increased the compressive strength of the pervious concrete while its permeability performance is reduced but within the allowable limit. The mixture with fine aggregate has higher freezing-thawing durability and abrasion resistance. The preliminary results of the effects of time delay to the performance of concrete show a deterioration in the compaction capability of the pervious concrete.

본 연구는 자전거도로 시스템이 활성화되어 있는 창원시를 대상으로 자전거 도로의 물리적 환경에 대한 공간 데이터를 구축하여 자전거도로 환경을 분석하고자 하였다. 물리적 환경을 평가하기 위한 지표는 문헌분석을 통하여 도출하였으며 각 평가 지표의 중요도 평가 및 가중치 설정을 위하여 전문가조사를 실시하였다. 최종적으로 도출된 8개의 물리적 환경 평가지표를 활용하여 현장 조사를 실시하였으며 수집된 자료는 ArcGIS Program을 이용하여 등급화 하였다. 평가지표별로 높은 점수를 획득한 구간의 면적비율은 녹시율(40%이상, 9.3%), 연결성(1.8이상, 9.8%), 자전거도로 유형(자전거 전용도로, 25.4%), 포장유형(아스팔트, 72.5%), 불법주차(무, 93.9%), 노면표시(유, 46.8%), 제한속도(30km 이하, 48.5%), 교통량(500/hr 이하, 44.3%)으로 나타났다. 8개의 평가지표를 중첩한 결과 1등급의 구간은 31-35점으로 대상지의 전체 도로 면적에서 12.4%로 나타났으며 득점요인은 도로의 유형과 녹시율로 나타났다. 또한 평균 녹시율이 35% 이상으로 나타나 자전거 이용에 있어 안전성과 쾌적성이 높은 것으로 분석되었다. 15점 미만을 획득한 5등급 구간의 경우 전체 도로면적의 24.5%를 차지하며 주요 요인은 불법 주정차, 노면표시 미비, 낮은 녹시율로 나타났다.

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.

PURPOSES: Recently, there are increasing bicycle accidents along with increasing bicycles users. Bicycle accidents occurred frequently by perpendicular collision form at intersection inner. In order to improve safety of bicycle, drivers need to be aware of bicycles on the road and intersection geometric designs need to be designed to reduce risk associated with collisions between bicycles and car. This study aims to review the location of bicycle crossing in the viewpoint of bicycle safety. METHODS: Four types of bicycle crossing by curve radius and driver's check around the behavior are set to simulate the risk of collisions between bicycles and car turning right. Simulation using fortran programming are conducted on total 60 cases. RESULTS : Bicycle crossing located behind of crosswalk is lower the risk of collisions with car in all cases. In addition to the larger curve radius of pavement edge at intersection and the more pay attention to the rear by the turn head to the right is too low the risk of collisions with car. CONCLUSIONS : It is show that the location of bicycle crossing is safer behind than in front of crosswalk in the viewpoint of bicycle safety.

This article deals with the transient analysis in bicycle shifting using a discrete chain model. Among the various components of a bicycle, we focused in the power-transmissions on the contact points between the chain element and sprocket. And by imposing kinematic motions on the front and rear derailleurs, we analyzed the shifting mechanism for increasing the rotational speed of rear wheel. In order to build the dynamic analysis model, we first tore down the real bicycle and measured each component's design parameters. Then we made 3-dimensional CAD models for each component related to the power transmission of a bicycle. Using the converted 3-dimensional dynamic model for the simulation program, we performed non-shifting and shifting dynamic analysis. As a result, we investigated the dynamic behaviors of a discrete chain model focused on the interaction between the chain and sprocket wheel.

PURPOSES: This study aims to suggest a proper left-turn treatment method for the bicycle traffic flow at four-legged intersections. METHODS: Four types of crossing methods are proposed and analyzed : (1) indirect left turn, (2) direct left turn, (3) direct left turn on a Bike Box, and (4) direct left turn on bike left turn lane. The VISSIM simulation tests were conducted based on forty-eight operation scenarios prepared by varying vehicle and bicycle traffic volumes. RESULTS : The results from the four-legged signalized intersections suggest that (1) the indirect left turn is appropriate when vehicle demand is high, (2) the direct left turn is efficient on most traffic situation but the safety is a concern, (3) the direct left turn on a Bike Box is appropriate when bicycle demand is high while vehicle demand is not, and (4) the direct left turn on a bike left turn lane is appropriate when both vehicle and bicycle demand are low. CONCLUSIONS : The direct left turn of bicycle provides more efficiency than the indirect left turn at the four-legged intersections but to apply the methods and to study more, advanced evaluation methods, related law, and insurance programs are needed.

This study analyzes about Bicycle saddle in operation through the analysis of Fatigue life and structural safety, equivalent Stress, maximum deformation. Maximum equivalent stress is analysis applied with force. The structural result of this study can be effectively utilized with the design of Bicycle saddle by investigating prevention and durability against its damage.

PURPOSES: This study proposes a novel method based on microscopic simulation models to evaluate bicycle passing ways in mixed traffic flow conditions at signalized intersections. METHODS: Both operational efficiency and safety are taken into consideration in the evaluation. A widely used performance measure, delay, is used for evaluating the operational efficiency. Regarding the safety evaluation, surrogate safety measures (SSM) to represent traffic conflicts and the level of crash severity, DeltaS and Max.DeltaV, are applied in the proposed method. RESULTS: Extensive simulations and statistical tests show that an integrated bike-box way is identified as the best in terms of operational efficiency and safety. CONCLUSIONS: The proposed method and outcomes of this study will be valuable for bicycle traffic operations and facility design.

This paper is the product development of environment and safety. In growing society, the bicycle is need to have a common goals for consumers convenience and theft prevention. The bicycle is movable means. But as times passed, that bicycle is strongly recommended to replace other vehicles because that is not produced to air pollution and energy(gas, diesel etc) insufficiency. As workers using a bicycle are increased, road for only bicycle is made by additionary. The bicycles happens to several moving accidents such as car accidents because of signal mismatch between bicycle users. However, using the development products of this paper, many accident problems for bicycle can be solved. As increasing of bicycles numbers, the high cost bicycles are too increased. So, the more theft of bicycle is also happened. The developed products(turn signal system and theft prevention system) through this study kept your bicycles from more convenience and more safe.

PURPOSES : Effective speed management is necessary for preventing traffic crashes on the road. Speed hump is known as an effective tool for managing speed. Unlike existing studies which are mainly focused on humps for vehicles, this study proposed a novel method to determine design parameters for bicycle speed humps based on a multi-criteria decision making process. METHODS : Three objectives including the effectiveness of speed reduction, bicycle safety, and user's comfortability were incorporated into the proposed evaluation framework for determining design parameters. A multi-criteria value function was also derived and utilized as a part of the proposed method. RESULTS : Extensive simulations and statistical tests show that an integrated bike-box way is identified as the best in terms of operational efficiency and safety. CONCLUSIONS : It is expected that the outcomes of this study can be a valuable precursor for developing design guidelines for bicycle road and facility.