13 October 2017 (Time: 15:15-17:00 Location: Bestuurs-Lieregg)

Title: Introduction to GMT Colloquium (pdf)
Speaker: Dr. Zerrin Yumak
Bounce Maps: An Improved Restitution Model for Real-time Rigid-Body Impact
Authors: Jui-Hsien Wang, Rajsekhar Setaluri, Doug L. James, and Dinesh K. Pai
Speakers: Jeroen Huisen and Navid Saremi
 Summary: We present a novel method to enrich standard rigid-body impact models with a spatially varying coefficient of restitution map, or Bounce Map. Even state-of-the art methods in computer graphics assume that for a single rigid body, post- and pre-impact dynamics are related with a single global, constant, namely the coefficient of restitution. We first demonstrate that this assumption is highly inaccurate, even for simple objects. We then present a technique to efficiently and automatically generate a function which maps locations on the object’s surface along with impact normals, to a scalar coefficient of restitution value. Furthermore, we propose a method for two-body restitution analysis, and, based on numerical experiments, estimate a practical model for combining one-body Bounce Map values to approximate the two-body coefficient of restitution. We show that our method not only improves accuracy, but also enables visually richer rigid-body simulations.

A Review of Building Evacuation Models
Authors: Erica D. Kuligowski, Richard D. Peacock and Bryan L. Hoskins
Speaker: Yiran Zhao

 Summary: Evacuation calculations are increasingly becoming a part of performance-based analyses to assess the level of life safety provided in buildings. In some cases, engineers are using back-of-the-envelope (hand) calculations to assess life safety, and in others, computational evacuation models are being used. This paper presents a review of 26 current computer evacuation models, and is an updated version of a previous review published in 2005. Models are categorized by their availability, overarching method of simulating occupants, purpose, type of grid/structure, perspective of the occupants, perspective of the building, internal algorithms for simulating occupant behavior and movement, the incorporate of fire effects, the use of computer-aided design drawings, visualization methods, and validation techniques. Models are also categorized based upon whether they simulate special features of an evacuation, including counterflow, exit blockages, fire conditions that affect behavior, incapacitation of the occupants due to toxic smoke products, group behavior, disabled or slower-moving occupant effects, pre-evacuation delays, elevator usage, and occupant route choice.