Modeling pedestrian evacuation movement in a swaying ship

With the advance in living standard, cruise travel has been rapidly expanding around the world in recent years. The transportation of passengers in water has also made a rapid development. It is expected that ships will be more and more widely used. Unfortunately, ship disasters occurred in these years caused serious losses. It raised the concern on effectiveness of passenger evacuation on ships. The present study thus focuses on pedestrian evacuation features on ships. On ships, passenger movements are affected by the periodical water motion and thus are quite different from the characteristic when walking on static horizontal floor. Taking into consideration of this special feature, an agent-based pedestrian model is formulized and the effect of ship swaying on pedestrian evacuation efficiency is investigated. Results indicated that the proposed model can be used to quantify the special evacuation process on ships.Comment: Traffic and Granular Flow'15, At Delft, the Netherland

G1-smooth branching surface construction from cross sections

This paper proposes a framework for constructing G1 surfaces that interpolate data points on parallel cross sections, consisting of simple disjoined and non-nested contours, the number of which may vary from plane to plane. Using appropriately estimated cross tangent vectors at the given points, we split the problem into a sequence of local Hermite problems, each of which can be one of the following three types: “one-to-one”, “one-to-many” or “many-to-many”. The solution of the “one-to-many” branching problem, where one contour on the i-plane is to be connected to M contours on the (i+1)-plane, is based on combining skinning with trimming and hole filling. More specifically, we first construct a C1surrounding curve of all M contours on the (i+1)-plane. Next, we build the so-called surrounding surface that skins the i-plane contour with the (i+1)-plane surrounding curve, and trim suitably along parts of the surrounding curve that connect contours. The resulting multi-sided hole is covered with quadrilateral Gordon–Coons patches that possess G1 continuity. For this purpose, we develop a hole-filling technique that employs shape-preserving guide curves and is able to preserve data symmetries. The “many-to-many” problem is handled by combining the “one-to-many” methodology with a zone-separation technique, that achieves splitting the “many-to-many” problem into two “one-to-many” problems. The methodology, implemented as a C++ Rhino v3.0 plug-in, is illustrated via two synthetic data sets and in the context of two realistic design examples. Finally, the paper concludes with discussing ongoing work towards improving the robustness and the applicability of the method regarding the surrounding curve construction step