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

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.802-805
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• 2014

본 연구에서는 스마트 디바이스를 이용하여 보행자의 상태를 감지하여 필요한 사용자의 정보에 대해 얻는 방법을 제안하고, 이를 분석하는 모델을 연구하여 예방 방안을 제공하는 서비스를 제안하였다. 분석 모델을 Sensing, Thinking, Action의 세 단계로 나누어 분류한 세부적인 수행 순서를 정하였다. Sensing 단계에서 센서, 디바이스, 어플리케이션 등을 통해 사용자에 대한 있는 그대로의 정보를 받아들여 디바이스가 인식하게 하고, 이를 분석해 사용자의 상태 및 상황에 대해 Thinking하고, 그에 맞는 Action을 취한다. 본 논문에서는 분석 모델의 정해진 수행 순서에서의 기능들을 설명하고, 그에 맞는 예상 구현 시나리오를 제시하였다.

• Korean Institute of Interior Design Journal
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• v.25 no.4
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• pp.147-155
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• 2016

In order to ensure a certain level of the quality of design, standardized evaluation indicators are being used as an objective criterion. Even though the evaluation indicators are quantifiable, limitations such as inefficiency and inconsistency caused by manual task in the evaluation process still have been found. BIM (Building Information Modeling) technology that is commonly adopted in architectural design process provides an environment which enables us to figure out a building model to be interpreted quantitatively with the basis of the building information model. It supports quantitative, consistent, accurate and quick evaluations so as to improve quality of design even in the initial design phase. This paper aims to establish BIM-enabled quantitative indicators and an evaluation framework to analyze building circulation even in early phase of design. The indicators are composed of 4 types (relative distance, accessibility, simplicity, pedestrian friendliness) and 7 sub-types. The evaluation framework is the process to derive Parameterized Path Value (PPV) as weighting on each indicator. For demonstrating the scalability of the suggested evaluation indicators and the framework, the authors implemented an evaluation tool and a case study has been carried out by using an actual building remodel project.

• Steel and Composite Structures
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• v.23 no.2
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• pp.205-215
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• 2017

The use of advanced fibre composite materials in bridge engineering offers alternative solutions to structural problems compared to traditional construction materials. Advanced composite or fibre reinforced polymer (FRP) materials have high strength to weight ratios, which can be especially beneficial where dead load or material handling considerations govern a design. However, the reduced weight and stiffness of FRP footbridges results in generally poorer dynamic performance, and vibration serviceability is likely to govern their design to avoid the footbridge being "too lively". This study investigates the dynamic behaviour of the 51.3 m span Wilcott FRP suspension footbridge. The assessment is performed through a combination of field testing and finite element analysis, and the measured performance of the bridge is being used to calibrate the model through an updating procedure. The resulting updated model allowed detailed interpretation of the results. It showed that non-structural members such as the parapets can influence the dynamic behaviour of slender, lightweight footbridges, and consequently their contribution must be included during the dynamic assessment of a structure. The test data showed that the FRP footbridge is prone to pedestrian induced vibrations, although the measured response levels were lower than limits specified in relevant standards.

• Journal of Korean Association for Spatial Structures
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• v.15 no.2
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• pp.79-86
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• 2015

This study investigated the embedded depth of guardrail posts through 3-D soil material model and carried out evaluation of the dynamic performance of guard rail. In order to calculate for embedded depth of sloping ground, displacement of guardrail posts is analyzed according to the embedded depth of experiment variables. Through the static test of guardrail posts, the maximum deflection was found to decrease the interval. By performing the dynamic test using the Bogie Car, that is confirmed the elastic modulus of the soil occuring the maximum deflection. Guardrail posts is considered to need for further reinforcement in the larger slope than the plains. This study researched about maximum displacement and deviation velocity through dynamic performance of guardrail system and conducted analysis about protection performance evaluation of passenger.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.3
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• pp.265-269
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• 2016

In this research, the performances of active hood lift system(AHLS) are investigated according to the structural improvement through the experimental test. After introducing the working principle of the AHLS activated by a gunpowder actuator, the structural problems that cause the inefficiencies in the actuation are analyzed to reduce the deployment time of system. Sequentially, the improved structural model is proposed base on the analysis. The deployment time of AHLS are evaluated by the experimental test, and it has been identified that the improved model can provide a faster deploying time of AHLS.

• International Journal of Highway Engineering
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• v.17 no.3
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• pp.107-115
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• 2015

PURPOSES : The purposes of this study are to compare the day and night characteristics and to develop the models of traffic accidents. in Rural Signalized Intersections METHODS : To develop day and night traffic accident models using the Negative Binomial Model, which was constructed for 156 signalized intersections of rural areas, through field investigations and casualty data from the National Police Agency. RESULTS : Among a total of 17 variances, the daytime traffic accident estimate models identified a total of 9 influence factors of traffic accidents. In the case of nighttime traffic accident models, 11 influence factors of traffic accidents were identified. CONCLUSIONS : By comparing the two models, it was determined that the number of main roads was an independent factor for daytime accidents. For nighttime accidents, several factors were independently involved, including the number of entrances to sub-roads, whether left turn lanes existed in major roads, the distances of pedestrian crossings to main roads and sub-roads, lighting facilities, and others. It was apparent that if the same situation arises, the probability of an accident occurring at night is higher than during the day because the speed of travel through intersections in rural areas is somewhat higher at night than during the day.

• Wind and Structures
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• v.4 no.4
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• pp.299-314
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• 2001

A study of wind effects was carried out at the Boundary Layer Wind Tunnel Laboratory (BLWTL) for the projected 558-m high free-standing telecommunication and observation tower for Jakarta, Indonesia. The objectives were to assist the designers with various aspects of wind action, including the overall structural loads and responses of the Tower shaft and the antenna superstructure, the local wind pressures on components of the exterior envelope, and winds in pedestrian areas. The designers of the Tower are the East China Architectural Design Institute (ECADI) and PT Menara Jakarta, Indonesia. Unfortunately, the project is halted due to the financial uncertainties in Indonesia. At the time of the stoppage, pile driving had been completed and slip forming of the concrete shaft of the Tower had begun. When completed, the Tower will exceed the height of the CN-Tower in Toronto, Canada by some 5 m.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.7-13
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• 2021

This paper presents an vulnerable road user (VRU) classification and tracking algorithm using vision and LiDAR sensor fusion method for urban autonomous driving. The classification and tracking for vulnerable road users such as pedestrian, bicycle, and motorcycle are essential for autonomous driving in complex urban environments. In this paper, a real-time object image detection algorithm called Yolo and object tracking algorithm from LiDAR point cloud are fused in the high level. The proposed algorithm consists of four parts. First, the object bounding boxes on the pixel coordinate, which is obtained from YOLO, are transformed into the local coordinate of subject vehicle using the homography matrix. Second, a LiDAR point cloud is clustered based on Euclidean distance and the clusters are associated using GNN. In addition, the states of clusters including position, heading angle, velocity and acceleration information are estimated using geometric model free approach (GMFA) in real-time. Finally, the each LiDAR track is matched with a vision track using angle information of transformed vision track and assigned a classification id. The proposed fusion algorithm is evaluated via real vehicle test in the urban environment.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.75-84
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• 2010

South Korea is seeking for a solution to the problems of traffic congestion and environment: the increase of bicycle use. However many people feel that using a bicycle is inconvenient. Therefore, we developed bicycle level of service model from the user's perspective so that the existing bicycle roads can be evaluated and improved. The purpose of this paper is to develop a bicycle level of service (LOS) model by considering user's satisfaction and multiple factors that affect bicycle LOS. Bicycle LOS criteria is estimated by applying an ordered probit model, which is suitable for research relating to choice. In addition, we determine the bicycle LOS using three-level(A-C) LOS structure from the user position considering the satisfaction level that people can distinguish clearly. The results show that the bicycle LOS is largely determined by the bicycle road width. Other factors are involved as well, including bicycle road type, the number of access and egress point on the bicycle road corridor, pedestrian volume, and frequency of meetings.