• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.74-84
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• 2015

The core activities of a bicycle manufacturer are design, engineering analysis, and manufacturing. Therefore, it is important to develop a configuration design system for bicycles in order to automate the design process and facilitate the use of design data in engineering analysis and manufacturing. In this paper, we present a method to develop a bicycle configuration design system based on the part-shape information model. The proposed method enables the construction of a CAD library using modeling functions with equations and parameters that are common to most 3D mechanical CAD systems. Furthermore, the part-shape information model ensures the independence between the configuration design system and the library, making it possible to extend the CAD library flexibly without changing the system architecture.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.267-278
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• 2000

Vehicle dynamic models in handing and stability analysis are divided into three groups: bicycle model, roll axis model and full vehicle model. Bicycle model is a simple linear model, which hag two wheels with load transfer being ignored. Roll axis model treats left and right wheels independently. In this model, load transfer has a great effect on nonlinearity of tire model. Effects of suspension system can be analyzed by using full vehicle model, which is included suspension stroke motions. In this paper, these models are validated and compared through comparison with road test, and the effects of suspension kinematics and compliance characteristics on vehicle motion are analyzed. In handling and stability analysis, roll axis model can simulate the real vehicle motion more accurately than full vehicle model. Compliance steer has a significant effect, but the effect of suspension kinematics is negligible.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.265-270
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• 2013

Strength design for a lightweight bicycle frame made of carbon/epoxy composite laminates was studied using Tsai-Wu's failure criterion. For the design of bicycle frames, reducing the weight of the frame is of great importance. Furthermore, the frame should satisfy the required strength under specific loading cases. In accordance with the European EN 14764 standard for bicycle frames, three loading cases-pedaling, vertical, and level loadings-were investigated in this study. Because of the anisotropic characteristics of composite materials, it is important to decide the appropriate stacking sequence and the number of layers to be used in the composite bicycle frame. From finite element analysis results, the most suitable stacking sequence of the fiber orientation and the number of layers were determined. The stacking sequences of $[0]_{8n}$, $[90]_{8n}$, $[0/90]_{2ns}$, $[{\pm}45]_{2ns}$, $[0/{\pm}45/90]_{ns}$ (n = 1, 2, 3, 4) were used in the analysis. The results indicated that the $[0/{\pm}45/90]_{3s}$ lay-up model was suitable for a composite bicycle frame. Furthermore, the weakest point and layer were investigated.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.647-652
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• 2000

This paper proposes a collision warning/avoidance algorithm using a trajectory prediction method. This algorithm is based on 2-dimensional kinematics and the Kalman filter has been used to obtain the information of the object vehicle. This algorithm has been investigated via computer simulation and showed a good trajectory prediction performance. The proposed collision warning/avoidance algorithm would enhanced driver acceptance for a collision warning/avoidance system.

• Spatial Information Research
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• v.20 no.3
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• pp.83-93
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• 2012

Recent environmental concerns have made interest in environment-friendly transportation means such as walking, biking, and public transportation. However, since it is difficult to move long distance by walking or biking, their scope of application is rather limited. On the other hand, public transportation can solve traffic congestion, a recent social issue, though its usability may depend on its time schedule. Currently available information services on public transportation in the Web do not reflect well such traits of the public transportation; thus, in some cases, they may provide wrong information to end users. To solve such problems and provide information based on timetable of public transportations, this paper proposes a STP(Space Time Point) data model. Unlike existing space-time data models, this model recognizes the bottommost element of an object as a point and structures these points in hierarchical way to define an object. In particular, It can make it possible to implement a variety of dynamic spatial objects changing object information according to time. An objective of this study is to design a STP model for bus and subway based on timetables of public transportation in Daejeon area and builds a system to provide path navigation. With the designed navigation function, a path from the Daejeon National Cemetery to Hannam University was searched by time slot. The result showed that the system provided different paths by time, as the system guided different paths when bus operation was limited in midnight. As existing data model could not provide such results, it is confirmed that the system can provide path navigation based on real-time traffic information. It is expected that based on such functionality, it is possible to provide additional functionalities by applying diverse data models such as real-time transport information or traffic history information.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.736_737
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• 2009

본 논문은 전기자전거용으로 쓰이는 500W급 매입형 영구 자석 동기전동기의 자석 형태에 따른 특성 변화에 대해 연구하였다. 전기자전거의 경우 낮은 코깅토크 특성을 필요로 하며, 부하의 변화 시에도 고출력 고효율 특성을 지니는 정특성 운전이 요구된다. 이를 위해 높은 관성력을 얻을 수 있는 외전형 타입의 모터가 필요로 하며, 많은 부하가 요구되는 지점에서 고출력 토크를 위해서는 매입형 영구자석 동기전동기가 요구되고 있다. 본 논문에선 500W급 매입형 영구자석 동기전동기의 특성 향상을 위하여 자석 형태에 따른 모터 특성을 비교 분석하였으며, 실제 최적화 모델을 제작 및 성능실험을 통해 제안된 모델의 타당성을 검증하였다.

• KIEAE Journal
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• v.7 no.3
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• pp.3-10
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• 2007

사회적 경제적 환경적 영향에 대한 장기적인 고려 없이 진행된 개발도상국가의 도시화와 인구증가는 도시의 슬럼화 등 다양한 문제를 초래하고 있다. 본 연구는 베트남 하이퐁시를 대상으로 생태적 도시계획모델을 제시하는 것을 목표로 한다. 본 연구에서 적용한 생태적 계획과정은 크게 네 단계로 구분할 수 있다. 첫째, 기존에 연구된 생태적 도시계획 과정 및 절차를 검토, 정리하였다. 둘째, 한국을 포함한 성공적 사례를 검토함으로써 베트남에 적용 가능한 전략과 친환경적 개발 요소 등을 도출하였다. 베트남과 비슷한 경제발전 과정을 거친 한국의 일산, 분당 등 생태도시 사례로 부터 네 가지 전략을 도출하였다. 셋째, 대상지 분석 및 토지적합성평가를 실시하였으며 절대보전, 상대보전, 개발가능 지역 등을 도출하였다. 마지막으로 앞의 세 단계를 토대로 생태적 신도시건설을 위한 토지이용계획을 수립하였고, 블루네트워크(수체계), 그린네트워크(녹지체계), 화이트네트워크(바람길체계), 휴먼네트워크(자전거 및 보행도로체계), 문화네트워크(역사자원체계)의 다섯 가지 네트워크개념을 적용하였다. 각 네트워크별, 각 네트워크간의 연결 및 순환을 강조함으로써 현존하는 자연적 문화적 자원을 보전, 신도시의 가치로 창출되게 하고자 하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.733-735
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• 2017

Because of the increasing necessity on sharing economy, numerous number of commercial platform based on sharing has been on the rise: car sharing, bike sharing, house sharing, book sharing, etc. And most of all, share house which aimed at dwelling problem, showed the greatest growth than the other economic models. But during the growth period, unforeseen problems also revealed its traces; the vacancy and reliability problem on the mutual platform. However, there is no way to resolve this situation now. Due to this reason, we will offer some keys to unlock existing problems on current share house platform here.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.83-86
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• 2009

전통문화지구로서의 전주시의 공공시설물 디자인 적용 가능성을 검토하였다. 실험에서는 지역 공공자전거 개발을 위한 전주시 이미지 설문 분석결과 전체적으로 지역분위기에 침체되어 있는 상황이며 역동적이고 활동적인 문화 활동 및 미래지향적 그리고 역할 모델을 모색하고 있었다. 또한 전통을 컨셉으로 하는 주요 경쟁도시(안동, 경주, 춘천 등) 가운데 어떻게 차별점을 구축하고 변별력있는 마케팅 구축이 필요한 것으로 나타났다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.25-30
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• 2013

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.