• The Transactions of the Korea Information Processing Society
• /
• v.3 no.5
• /
• pp.1070-1081
• /
• 1996

In this research, a model was developed for estimating the queue length of vehicles, based on occupancy time of each vehicle collected by loop detectors which were setup at the upstream of urban street. The estimation model suggestes a method which minimizes architectural effects of the street, such as existence of pedestrian crossing, for future applications to the field. The estimation model suggested in this research was established based on real traffic data collected at up-stream detectors in Kangnam Subway station, Seoul, and the formula of the model is based on Multi-Polynomial equations. Consequence of the experiments showed that the model can adequately and in real-time mode measure length of the queue which were constructed at the 80 to 90 meters away from the upstream detectors. The estimation accuracy of the model was verified in statistical analysis conducted by regressing analysis and test results in real traffic situation.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2010.09a
• /
• pp.42-49
• /
• 2010

현재 대규모 실내공간이 증가하고 있고, 이에 따른 화재 등의 사고가 발생함에 따라 화재대피시스템과 같은 실시간 실내 응용에 대한 관심이 증대되고 있다. 그러나 학문적 연구 또는 상업용 시스템에서 사용되는 화재모델이내 보행자 모델은 대부분 2D 기반의 CAD와 같은 파일구조를 기반으로 하고 있으며 가상데이터를 이용한 시뮬레이션에 초점을 두고 있다. 따라서 이들을 실내 센서 등을 이용한 실시간 시스템으로 구축하기 위해서는 몇 가지 문제점들이 해결되어야 한다. 우선, 실내공간의 의미 있는 관계정보를 포함하는 위상적인 3D 모델이 필요하다. 또한, 실내 센서들에 의해 감지된 보행자의 이동을 저장하고, 저장된 데이터를 이용하여 실시간 안내를 위해서는 실내데이터 구축에 공간 DBMS를 이용해야 한다. 본 연구에서는 실내보행자 모델에서 두 가지 개선점을 제시하고자 한다. 첫째는, 간단한 3D 실내 모델구축과 공간 DBMS와 연계된 보행자 시뮬레이터를 구현하는 과정을 제시한다. 둘째는, 보행자의 가시성(visibility)에 대한 영향이 반영된, 개선된 floor field 모델을 제안한다. 이와 같은 과정을 캠퍼스 건물에 적용하고 시뮬레이션을 수행하는 과정을 예시하였다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.52-57
• /
• 2012

Proper door effort is required for the safety of passenger and pedestrian while securing door operating convenience. 3D finite element analyses for a hybrid door checker were carried out to estimate door checker arm resistance force. And, from the estimated door checker arm resistance force and theoretically calculated self-closing force, door effort was predicted. The analysis results at checker arm peaks showed excellent correlation with the test results. Also, in order to reduce solving time, a modified model with simple spring element was investigated. Finally an equation to easily calculate checker arm resistance force from checker arm shape and spring constant was suggested and its usefulness in early design stage was discussed.

• Electronics and Telecommunications Trends
• /
• v.29 no.6
• /
• pp.113-125
• /
• 2014

최근 모바일 단말 기술의 발전과 무선망의 성능 향상에 따른 다양한 서비스가 제공되고 있는 추세이며, 위치정보인식시스템과 결합된 서비스에 많은 관심이 높아졌다. 본고에서는 GPS(Global Positioning System)의 신호가 미치지 못하는 건물의 실내환경에 적합한 경로 안내서비스 및 지하시설물 안내 등 초정밀 실내 측위 서비스를 제공하기 위한 융합 측위 방안을 제안한다. 융합 측위 방안은 실내외 연속 측위를 위해 실외에서는 GPS를 이용하고 실내환경에서는 WLAN 기반의 측위 전용 AP(Access Point)를 이용, 전파신호의 LoS(Line of Sight)를 확보하여 측위하고 전파음영지역에서는 스마트폰의 가속도, 자이로센서 등 여러 가지 관성센서를 활용하여 PDR(Pedestrian Dead Reckoning) 알고리즘 등을 적용하여 측위한다. 또한 측위 정확도 향상 및 오차를 줄이기 위한 방법으로 LSE(Least Squire Estimation) 및 EKF(Extended Kalman Filter), KNN(K-Neighbor Node)/MSSM(Maximum Signal Strength Model) Algorithm 등 다양한 융합 측위 알고리즘을 적용하여 실내환경에 적합한 최적의 초정밀 실내 측위 서비스를 제공한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2010.06a
• /
• pp.147-148
• /
• 2010

최근 타 교통수단으로 인해 발생하는 교통사고나 환경오염 등의 문제들을 보완하는 녹색 교통수단의 하나로써 보행교통에 대한 관심과 연구가 활발하게 증가되고 있다. 하지만 차량교통에 관한 연구에 비해 보행 교통에 관한 연구는 미미하며, 특히 우리나라 여건에 맞는 보행 환경의 서비스 수준과 보행 안전도 등에 대한 객관적 평가 모형의 개발이 필요한 실정이다. 이에 본 연구에서는 도시 내 보행 환경 요소를 정량적으로 계산하고 측정할 수 있는 평가 지표인 그린 스코어(Green Score)를 개발하고자 하였다. 본 논문에서 제시한 그린 스코어 측정 모형은 실제 물리적인 보행공간을 기반으로 가상의 시스템에 적용되어 보행 이동 패턴의 가시화, 보행 환경의 쾌적성과 편의성 평가 예측에 활용될 수 있을 것이다.

• Smart Structures and Systems
• /
• v.18 no.1
• /
• pp.17-29
• /
• 2016

In this paper, the possibility of using human induced loading (HIL) to detect a decrease of tension in the cable-stays of an existing footbridge is investigated. First, a reliable finite elements model of an existing footbridge is developed by calibration with experimental data. Next, estimates of the tension in the cables are derived and their dependency on the modal features of the deck is investigated. The modelling of the HIL is briefly discussed and used to perform the nonlinear, large strain, dynamic finite elements analyses. The results of these analyses are assessed with focus on characterizing the time histories of the tension in the cables under pedestrian crossing and their effects on the deck response for different initial conditions. Finally, the control perspective is introduced in view of further research.

• International Journal of High-Rise Buildings
• /
• v.5 no.2
• /
• pp.105-115
• /
• 2016

In the process of exploring sustainable development, major cities in China are expanding metro systems as a strategy to reduce the negative environmental and social consequences of fast-paced motorization. A metro station is not only a transportation node, but also a place where diverse activities can be performed. Therefore, the realization of the spatial potential for human interaction is the essence of the strategy for integrated development in metro station areas. For this paper, 10 well-developed metro stations in Central Shanghai were selected to investigate the correlation between accessibility and spatial performance in station areas. The spatial performance in station areas is significantly affected by metro configuration. However, both vehicle and pedestrian accessibility show weak influence on spatial performance. A synergistic model was then developed to provide quantitative support for transit-oriented development in metro station areas.

• Journal of Korean Association for Spatial Structures
• /
• v.4 no.4 s.14
• /
• pp.65-76
• /
• 2004

Walking loads are usually considered as nodal loads in the finite element vibration analysis of structures subjected to walking loads. Since most of the walking loads act on elements not nodes, the walking loads applied on the elements should be converted to the equivalent nodal walking loads. This paper begins with measuring walking loads by using a force plate equipped with load cells and investigates the characteristics of the walking loads with various walking rates. It is found that the walking loads are more affected by walking rates than other parameters such as pedestrian weight, type of footwear, surface condition of floor etc. The measured walking loads are used as input loads for a finite element model of walking induced vibration. Finally, this paper proposes the equivalent nodal walking loads that are converted from the walking loads acting on elements based on finite element shape functions. And the proposed equivalent walking loads are proved to be applicable for efficient analysis of floor vibration induced by walking loads.

• Journal of Korean Association for Spatial Structures
• /
• v.17 no.2
• /
• pp.71-77
• /
• 2017

In this study, the boundary non-linear analysis of the sky bridge subjected to walking load and running load is performed. The sky bridge is installed in the mid-story between two buildings and the walking load and running load induced by pedestrians are measured by load cell. LRB is modeled as a non-linear hysteresis model to accurately represent the behavior of LRB. For the serviceability evaluation of sky bridge, the acceleration responses of sky bridge are analyzed based on ISO 2631-2 and the velocity response are analyzed based on standards Bachmann &Amann. In serviceability evaluation of this sky bridge, the pedestrian can not perceive the vibration except for resonance running loads consequently. Therefore, it is concluded that this sky bridge haven't problem in the serviceability.

• Journal of Korean Institute of Industrial Engineers
• /
• v.22 no.4
• /
• pp.551-565
• /
• 1996

We present the required handover capacity of personal communication service exchange(PCX). We use the flow-based mobility model. The dimension of PCX area and the number of radio port controller(RPC) in a PCX are determined according to the traffic carrying capacity of switching system and RPC. For the rectangular or square-shaped PCX/RPC area and the personal communication service environment with pedestrian traffic, we perform numerical computations to investigate the sensitivity to cell size, portable station(PS) terminating traffic, its density, and its average speed. The results how that the size of PCX/RPC area decreases as the PS terminating traffic and the PS density increase, and the PCX handover capacity required is more than 73,000 in the number of transactions per hour.