• International Journal of Highway Engineering
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• v.12 no.4
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• pp.11-16
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• 2010

Various researches have been performed on the topic of pedestrian traffic flow. At the beginning, the modeling and simulation method for the vehicular traffic flow was simply applied to pedestrian traffic flow. Recently, CA based simulation models are frequently applied to pedestrian flow analysis. Initially, the square Lattice Model is a base model for applying to pedestrians of counterflow and then Hexagonal Lattice Model improves its network as a hexagonal cell for more realistic movement of the avoidance of pedestrian conflicts. However these lattice models express only one directional movement because they express only one directional movement. In this paper, MLPM (the Multi-Layer Pedestrian Model) is suggested to give various origins and destinations for more realistic pedestrian motion in some place.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.424-428
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• 2011

기후변화의 영향으로 대규모 호우와 예측이 어려운 국지성 호우가 전 세계적으로 빈번하게 발생하고 있으며, 우리나라 또한 최근 강수일수의 감소와 강수량 및 집중호우의 증가추세가 보고되고 있다. 집중호우에 따른 피해를 저감시키기 위한 비구조적 대책으로써 홍수범람 위험지역에 대해서는 침수면적이나 침수심도의 예측은 풍수해로 인한 인명 및 재산피해를 최소화하기 위한 중요한 정보로 활용될 수 있다. 비정방향격자기반 2차원 홍수범람 해석모형은 고정확도의 해석결과를 제공하지만 범람모의를 위한 입력 자료의 구축과 모의시간의 제약성으로 인해 범람예측의 신속성을 확보하기 어렵고, 다른 수리 수문 모형과의 결합이 상대적으로 어려우며, 다양한 래스터 DB들과의 호환이 어려워 홍수피해액을 산정 또는 예측하기 어렵다는 단점을 가지고 있다. 따라서 본 연구에서는 지반고를 고려하여 범람류의 전파거동을 해석하는 정방형격자기반의 2차원 홍수범람해석기법과 다차원 피해액 산정기법을 결합하여 2002년 태풍 '루사'로 인한 '동막', '장현' 저수지의 동시붕괴로 인한 피해지역의 침수편입률 및 침수피해액을 산정하고 실측 침수심도와 피해액 통계자료를 활용하여 모의결과의 정확도를 검증한다.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.169-177
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• 2009

In this paper, the rotated hexagonal lattice model (RHLM) was proposed, which is applied to pedestrian flow, and developed the simulation model for the pedestrian counterflow. RHLM is an upgrade version of the square lattice model(SLM) and hexagonal lattice model(HLM). The simulation was performed at the hexagonal lattice $20{\times}20$ and evaluated by different speed, density and flow conditions. Simulation results are compared with SLM and show that RHLM can replicate the characteristics of pedestrian traffic more effectively and reliably than any other existing models from several perspectives. First, RHLM can explain the shortest-path movement of pedestrians and more realistic avoidance motion. If they cannot move straight direction, they can move shorter distance from previous position to destination. Second, RHLM reflects the characteristics that the pedestrian can move with higher capacity and the speed of pedestrian flow is hard to zero.

• Journal of Korea Water Resources Association
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• v.36 no.5
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• pp.799-810
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• 2003

Hydrologic models generally require land surface analysis to different topographic parameters defined as direct or indirect input variables to the model. Specially GIS supply the these parameters from digital data set of land surface The sensitivity analysis to DEM(Digital Elevation Model) resolution and the threshold area are of GIS extracted digital data set applied GIUH(Geomorphological Instantaneous Unit Hydrograph)model is investigated. Also it is compared the responses of GIUH model as input data of stream networks from digital data set(blue line) of NGIS and those extracted from DEM of various grid sizes. The results shows that the GIUH model is significantly affected by the DEM resolution and threshold area. According to the results, DEM grid size is suitable from 25m to 50m. Also threshold area is in the range of 30%∼50% for exceedance probability.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.316-322
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• 2009

This paper presents a preliminary study to monitor the lateral behavior of pile foundation using multiplexed fiber Bragg grating(FBG) sensors. In the Preliminary study, an 1.7 meter long cantilever beam with the shape of square hollow box was fabricated and tested under the static loading. Four FBG sensors were multiplexed in a single optical fiber and installed into the top and bottom of the cantilever beam. The strains are directly measured from FBG sensors followed by curvature calculations based on the plane section assumption. Vertical deflections are then estimated using the regression analyses based on the geometric relationships. It has been found that excellent correlation with conventional sensing system was observed. The success of the test encourages the use of the FBG sensing system as a monitoring system for pile foundations. However, further consideration should be given in the case of the sensor malfunction for the practical purpose.