• Title/Summary/Keyword: bike

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Development of Smart Speed Bump Using Non-newtonian Fluid (비뉴턴 유체를 이용한 스마트 과속방지턱 소재 개발)

  • Jung, Injun;Kim, Eunjung;Yu, Woong-Ryeol;Na, Wonjin
    • Composites Research
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    • v.35 no.4
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    • pp.277-282
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    • 2022
  • In this study, a smart material applicable to speed bumps was developed using low-cost starch and waterbased suspensions, and their properties were investigated. Viscosity and shear stress according to the shear rate was measured by a rheometer to observe shear thickening behavior according to starch concentration. The shear thickening phenomenon and applicability to speed bumps were identified macroscopically via drop weight test and bike driving test, measuring the vibration after impact with a driving speed of 5-25 km/h. As a result of the viscosity measurement, shear thickening occurred after the shear thinning region at the beginning, and the critical strain causing the shear thickening phenomenon decreased as the concentration of starch increased. Also, the viscosity and shear stress increased significantly with the increase of the starch concentration. As a result of the drop weight test and the bike driving test, the suspension was changed to a solid-like state in a short time, and the impact energy was absorbed in the fluid. The shear thickening phenomenon easily occurred as the concentration of the fluid and the applied impact (velocity) increased. Therefore, it can be proposed the development of a smart speed bump material that operates in the range of 5-25 km/h with a Non-Newtonian fluid based on water and starch.

people who live with two wheels: MTB's life who changed their jobs through their leisure (두 바퀴 인생을 사는 사람들: 여가활동을 통해 관련 직업으로 이직한 MTB 참여자의 삶)

  • Ham, Hyung-Seok;Won, Young-Shin;Im, Sung-Chul
    • 한국체육학회지인문사회과학편
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    • v.55 no.2
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    • pp.95-110
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    • 2016
  • The purpose of this research is to analyze and understand MTB(mountain bike) participants' life in subcultural perspective. This research was completed by 8 people live in Seoul, Gyeonggi and Incheon who regularly participated their activity and changed their job to MTB. Observe them by participation, in-depth interview, field notes and researcher's daily records were methods to collect these data. To accomplish this purpose of study, I chose ethnographic Research. As a result, feeling doubt of their previous life, be caught in unique fun of MTB that made them to think MTB leisure seriously as a job, experience of its professionalism they learnt, and changed their job voluntarily were majority opinions. After they changed their job, they seems to have weisure life, more enthusiastic, got positive attitudes than before. Final conclusion of this report is 'close relationship between MTB facility and day life ' and 'tourism's attraction brought them to change their job. This changes gave them satisfaction to their personal life. In socially, it made a large contribution for development of leisure industry by creating new jobs like MTB tour guide and MTB assemblyman.

The Urban Parks and Rivers Contribute to the Citizen Satisfaction and Utilization in Uijeongbu City

  • Kim, Yoo-Ill
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.5_2
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    • pp.151-162
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    • 2010
  • This research aimed at measuring Park and Green Satisfaction (PGS) using subjective indicators of 'surface, line and spot' green evaluated by citizens. Also frequency of visits to park and green measured using objective indicators (number of visits) to find the relationship with PGS. A conceptual model of PGS was developed to relate evaluation to satisfaction and finally to utilization of open spaces. A sample of 500 questionnaire survey was employed for Uijeongbu City in Korea. A Structual Equation Modeling (AMOS) techniques was used to test the hypothesized relationship among factors (construct). As a result, first, PGS was explained by three latent factors of 'urban park' (${\gamma}=0.54$), 'linear facilities' (${\gamma}=0.25$), and 'surface green' (${\gamma}=0.15$) respectively. These three exogenous construct was found very useful classification system for open spaces of cities. Second, PGS (${\gamma}=0.34$) was found as a mediating variable to utilization of open spaces and also PGS was closely related to citizens Environmental Quality Satisfaction (EQS), such concept as, 'livability' and 'aesthetic quality'. The more satisfied with park and green the more people use the space. The PGS was an important QOL indicator together with the subjective indicator of 'livability'. Third, jogging and walking trails and bike ways along the river corridor was the most important green facilities contribute to the PGS and EQS. The near the distance (within 500m) the more number of visit to river corridor (green way). The river corridor promote accessibility to nature and other parks.

A Study on the Park Using Pattern Focusing on user Behavior in River-eco-park (하천생태공원 이용자의 이용행태에 따른 시설이용패턴에 관한 연구)

  • Back, Jun Wook;Park, Jong Min;Kim, Jong Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.5
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    • pp.2157-2168
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    • 2013
  • This study is about facilities using pattern for 'River-eco-park' that is Hwa-myeong Eco-park, Sam-rak Eco-park, Maek-do Eco-park. Through doing surveys, most patterns could be divided 5 patterns; 'Eco observation facility pattern', 'Promenade pattern', 'Bike path pattern', 'Sports facility pattern', 'Fitness center pattern'. Then we find channel of movement of user patterns by follow-up surveys. On the basis of this surveys, we are going to suggest some directions for River-eco-park design.

Applying System Dynamics Model to Estimate the Effects of Healthy City Policies on Reducing Social Cost (시스템다이내믹스 기법을 이용한 건강도시화 정책의 사회적비용 절감효과 분석)

  • Kim, Eun Jung;Kim, Young-Pyo
    • Korean System Dynamics Review
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    • v.13 no.3
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    • pp.23-46
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    • 2012
  • The purpose of this paper is to estimate effects of healthy city policies on reducing social costs. The analyses were dune at the cities, counties, and communities levels in 2009, and covered Seoul Metropolitan Area(SMA). For estimation of reducing social costs, it developed a system dynamics(SD) model that analyzed causal relationships between physical inactivity rates, the number of deaths, medical expenses, and total social costs. Simulation period of SD was from 2009 to 2030. Three alternatives were proposed with combinations of length of bike lanes, number of bus routes, crime rates, self-reported good health status rates, and obesity rates. The total estimated cost of physical inactivities from 2009 to 2030 was 31.9 trillion won from the future forecast without policies. As a result of simulations with three alternatives, there were economic benefit approximately from 119.7 billion won to 1.16 trillion won. This study contributed to better understanding the economic benefits of healthy cities that were associated with design of built environment and physical activity. It also emphasized the importance of healthy cities planning as one of national welfare polices.

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High Power Li Battery Pack and Battery Management System for Electric Bike (전기자전거용 고출력 리튬 배터리 팩 및 관리시스템)

  • Nam, Jong-Ha
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1217_1218
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    • 2009
  • 현재 국내를 비롯하여 세계적으로 녹색성장, 친환경 등의 열풍이 고유가와 화석연료의 고갈위기와 맞물려 활발히 진행되고 있다. 이미 미국, 영국, 프랑스, 이태리, 일본 등의 선진국에서는 자연 친화적, 경제적 실리 추구 및 편리성을 추구하면서 청정 에너지를 사용하는 "미래형 이동수단"에 큰 관심을 갖고 우리보다 한발 앞서 나가고 있다. 2005년 2월 16일 발효된 기후변화의 주 요인인 온실가스 배출 감축을 위한 교토의 정서 또한 이러한 친환경이란 말과 무관하지 않다. 교토의정서의 발효 이후 세계 각국은 의무화된 규제조항을 만족하기 위해 막대한 자본을 투입하고 있다. 우리나라의 경우 온실가스 배출량이 세계 9위에 달하고 있으며, 전체 온실가스 배출량의 82.5% 정도가 화석에너지의 사용에 의해 발생되고 있다. 이중 이산화탄소의 경우 전체 배출량의 27%를 자동차에서 배출되며, 이로 인해 세계 각국에서는 자동차에서의 배출가스를 규제하는 조항을 법제화하고 있다. 이러한 규제는 앞서 미국의 경우 캘리포니아 주정부에서 1998년부터 전기자동차 사용을 의무화하는 ZEV 규제를 입법화하면서 본격화되었고, 무공해 및 저공해 자동차의 개발이 활발하게 진행되었다. 또한 고유가 시대로 접어들면서 대체에너지에 대한 필요성이 한층 고조되고 있는 실정이다. 이중 전기자전거는 배터리를 통해 무공해, 무소음이라는 장점을 가지고 있으며, 유지관리비가 거의 들지 않고 교통체증을 완화시켜주며, 주차에 신경쓰지 않아도 되어 교통수단에 혁신을 가져다 줄 것이라 생각된다. 또한 전기자전거의 경우 배터리를 동력원으로 사용하며 전동스쿠터 등에서의 문제점인 일충전 주행거리에 제약을 받지 않아 최근 중국 등에서 보급이 급격히 확산되고 있는 추세에 있다. 하지만 대부분 납축전지, 니켈-카드뮴 등의 배터리가 사용되고 있어 중량, 수명, 중금속에 의한 환경오염 등의 다양한 문제점을 내포하고 있다.

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A Study on Establishment of the Directions for Environmentally-friendly Restoration of Underground Stream by Citizen Participation - In the Case of the Yangjae Underground Stream Restoration Project - (주민참여를 통한 도시복개하천의 환경친화적 복원방향설정에 관한 연구 - 과천 양재천 복개하천 복원사업을 사례로 -)

  • Song, Byeong Hwa;Yang, Byoung-E
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.2
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    • pp.33-44
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    • 2006
  • The purpose of this study is to establish future directions of environmentally-friendly restoration of Yangjae underground stream and reflect various opinions of inhabitant in the plan and design process. The opinions from the citizens include the economic and environmental suitability of the restoration projects and preference for the future directions of restoration. The citizens are favorable to removing the existing parking lot and want to have jogging course, walking path and bike road in the stream. Different opinions and resulted in preferred facilities and diminishing existing park along the stream depending on the restoration influencing zone. As a result, citizens agree in restoration but they have different opinions about the feasibility of new facilities, streams restoration and central park reduction locally. It is desirable to reflect the opinions of citizens in the process of plan and design of restoration project.

Design Development of Street Furniture for Improvement of Urban Environment - Focusing on "Y" District, a part of the Seoul Design Street Project -

  • Kim, Kook-Sun
    • Journal of the Korea Furniture Society
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    • v.20 no.6
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    • pp.581-589
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    • 2009
  • Under 'The Design Street' Project, one of the urban environment improvement projects of Seoul, the facilities on the street have been greatly varied in terms of design. In addition, the municipal authority has pushed each district to develop its own identity based on the integrated design of the city. This study was aimed to propose a design which could solve the current problem in street furniture in terms of environmental improvement through an analysis on current street conditions in "Y" District as a part of Seoul Design Street Project. It has attempted to propose 11 street furnitures based on the basic strategy of 'Soft City' which has been promoted by Seoul City in accordance with the Seoul Public Facility Guidelines as 1. Airy Design, 2. Integrated Design, 3. Collaborative Design and 4. Sustainable Design. Among them, for the total design in Seoul six facilities - kiosk, manhole, traffic signal controller, public phone, road sign and waste receptacle were proposed by Seoul City have been accepted. For local differentiation, on the contrary, five items - planter bench, bollard, lifter, bike rack and fence have been newly designed and proposed. Furthermore, it is essential to carry out systematic supervision and continuous management on the detail design and construction of current regional design development projects.

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Osborne-Cotterill Lesion a Forgotten Injury: Review Article and Case Report

  • Vargas, Daniel Gaitan;Woodcock, Santiago;Porto, Guido Fierro;Gonzalez, Juan Carlos
    • Clinics in Shoulder and Elbow
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    • v.23 no.1
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    • pp.27-30
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    • 2020
  • Osborne-Cotterill lesion is an osteochondral fracture located in the posterolateral margin of the humeral capitellum, which may be associated with a defect of the radial head after an elbow dislocation. This lesion causes instability by affecting the lateral ulnar collateral ligament over its capitellar insertion, which is associated with a residual capsular laxity, thereby leading to poor coverage of the radial head, and hence resulting in frequent dislocations. We present a 54-year-old patient, a physician who underwent trauma of the left elbow after falling from a bike and suffered a posterior dislocation fracture of the elbow. The patient subsequently presented episodes of instability, and additional work-up studies diagnosed the occurrence of Osborne-Cotterill lesion. An open reduction and internal fixation of the bony lesion was performed, with reinsertion of the lateral ligamentous complex. Three months after surgery, the patient was asymptomatic, having a flexion of 130° and extension of 0°, and resumed his daily activities without any limitation. Currently, the patient remains asymptomatic 2 years after the procedure. Elbow instability includes a large spectrum of pathological conditions that affect the biomechanics of the joint. The Osborne-Cotterill lesion is one among these conditions. It is a pathology that is often forgotten and easily overlooked. Undoubtedly, this lesion requires surgical intervention.

New Approach to Two-wheeler Detection using Correlation Coefficient based on Histogram of Oriented Gradients

  • Lee, Yeunghak;Shim, Jaechang
    • Journal of Multimedia Information System
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    • v.3 no.4
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    • pp.119-128
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    • 2016
  • This study aims to suggest a new algorithm for detecting two-wheelers on road that have various shapes according to the viewing angle for vision based intelligent vehicles. This article describes a new approach to two-wheelers detection algorithm riding on people based on modified Histogram of Oriented Gradients (HOG) using correlation coefficient (CC). The CC between two local area variables, in which one is the person riding a bike and other is its background, can represent correlation relation. First, we extract edge vectors using HOG which includes gradient information and differential magnitude as cell based. And then, the value, which is calculated by the CC between the area of each cell and one of two-wheelers, can be extracted as the weighting factor in process for normalizing the modified HOG cell. This paper applied the Adaboost algorithm to make a strong classification from weak classification. In this experiment, we can get the result that the detection rate of the proposed method is higher than that of the traditional method.