• Title/Summary/Keyword: Bertrand curve

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Lane Detection Using Road Geometry Estimation

  • Lee, Choon-Young;Park, Min-Seok;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.226-231
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    • 1998
  • This paper describes how a priori road geometry and its estimation may be used to detect road boundaries and lane markings in road scene images. We assume flat road and road boundaries and lane markings are all Bertrand curves which have common principal normal vectors. An active contour is used for the detection of road boundary, and we reconstruct its geometric property and make use of it to detect lane markings. Our approach to detect road boundary is based on minimizing energy function including edge related term and geometric constraint term. Lane position is estimated by pixel intensity statistics along the parallel curve shifted properly from boundary of the road. We will show the validity of our algorithm by processing real road images.

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Numerical Analysis of Infiltration in Permeable Pavement System considering Unsaturated Characteristics (불포화 특성을 고려한 투수성 포장 시스템의 침투성 수치해석)

  • Kim, Seungbae;Ahn, Jaehun;Teodosio, Bertrand;Shin, Hyunjun
    • Journal of the Society of Disaster Information
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    • v.11 no.3
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    • pp.318-328
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    • 2015
  • Effective urban flood reduction and restoration of natural water cycle at present include the application of permeable pavements. The application of permeable pavement addresses urban water cycle and disaster related events which gained attention internationally. However, few researches have been conducted to investigate unsaturated behavior and evaluate the water characteristics curves of these type of pavement materials most especially in the unsaturated state. In this study, first the saturated permeability and the soil-water characteristics curve of a pervious concrete are evaluated based on laboratory tests, and, based on experimental results, the infiltration of permeable pavement system is numerically modelled. In the soil-water characteristics curve of a pervious concrete, the volumetric water content drops very steeply after the air entry value with increasing matric suction. From the finite element analyses, the performance of the permeable pavement when compared to impermeable pavement, confirmed that the whole system effectively delayed and reduced runoff.