Modelling evacuation using escalators: a London Underground dataset

This paper presents a brief analysis of an escalator human factors dataset collected in a London Underground (subway) station in England. The data analysis highlights and quantifies a variety of escalator human factors. Using the buildingEXODUS evacuation software, a series of evacuation scenarios of a hypothetical underground station are then presented. The simulation results demonstrate that escalator strategies and associated human factors can have a considerably influence upon an evacuation compared to using stairs alone

Rotation identification in geometric algebra : theory and application to the navigation of underwater robots in the field

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Field Robotics 32 (2015): 632–654, doi:10.1002/rob.21572.We report the derivation and experimental evaluation of a stable adaptive identifier to estimate rigid body rotations using rotors in Geometric Algebra (GA). This work is motivated by the need for in situ estimation of the alignment between sensors commonly used in underwater vehicle navigation. Here we derive an adaptive identifier using a geometric interpretation of the error to drive first-order rotor kinematics. We prove that it is Lyapunov stable, and we show that it is asymptotically stable in the presence of persistent excitation. We use the identifier to estimate the alignment between the Doppler velocity log sonar and the fiber optic gyrocompass used by underwater vehicles for dead reckoning (DR). We evaluate this method in the laboratory with a remotely operated vehicle (ROV), and then with an autonomous underwater vehicle (AUV) operating in the field at 1,200 m depth. Our results show that this technique reduces dead reckoning navigation errors on these platforms and provides comparable performance to previously reported SO(3) constrained Linear Algebra (LA) approaches. The rotor identifier has a number of advantages over these previously reported methods, including a more straightforward derivation, simpler gain tuning, increased computational efficiency, and reduced data manipulation.This work was supported in part by the National Defense Science and Engineering Graduate Program (MJS), the Edwin A. Link Foundation (MJS), the WHOI Academic Programs Office (MJS), The Jessie B. Cox Endowed Fund in Support of Scientific Staff (JCK), and The Penzance Endowed Fund in Support of Assistant Scientists (JCK)

Relationship between red blood cell lifespan and endogenous carbon monoxide in the common bottlenose dolphin and beluga

Certain deep-diving marine mammals (i.e., northern elephant seal (Mirounga angustirosis), Weddell seal (Leptonychotes weddellii)) have blood carbon monoxide (CO) levels that are comparable to those of chronic cigarette smokers. Most CO produced in humans is a by-product of heme degradation, which is released when red blood cells (RBC) are destroyed. Elevated CO can occur in humans when RBC lifespan decreases. The contribution of RBC turnover to CO concentrations in marine mammals is unknown. Here, we report the first RBC lifespans in two healthy, marine mammal species with different diving capacities and heme stores, the shallow diving bottlenose dolphin (Tursiops truncatus) and deep-diving beluga (Delphinapterus leucas) and relate the lifespans to the levels of CO in blood and breath. The belugas, with high blood heme stores, had the longest mean RBC lifespan compared to humans and bottlenose dolphins. Both cetacean species were found to have three times higher blood CO content compared to humans. The estimated CO production rate from heme degradation indicates some marine mammals may have additional mechanisms for CO production, or delay CO removal from the body, potentially from long duration breath-holds

Atomic Resonance and Scattering

Contains reports on nine research projects.U.S. Energy Research and Development Administration (Contract EG-77-S-02-4370)U. S. Air Force - Office of Scientific Research (Contract F44620-72-C-0057)Joint Services Electronics Program (Contract DAAB07-76-C-1400)National Science Foundation (Grant PHY75-15421-AO1)National Science Foundation (Grant PHY77-09155)National Science Foundation (Grant CHE76-81750)U. S. Air Force - Office of Scientific Research (Grant AFOSR-76-2972A

Atomic Resonance and Scattering

Contains reports on eight research projects.National Science Foundation (Grant PHY77-09155)Joint Services Electronics Program (Contract DAAG29-78-C-0020)U. S. Department of Energy (Grant EG-77-S-02-4370)National Science Foundation (Grant DMR 77-10084)National Aeronautics and Space Administration (Grant NSG-1551)U. S. Air Force - Office of Scientific Research (Grant AFOSR-76-2972)National Science Foundation (Grant CHE76-81750

Atomic Resonance and Scattering

Contains reports on eight research projects.National Science Foundation (Grant PHY83-06273)National Bureau of Standards (Grant NB83-NAHA-4058)National Science Foundation (Grant PHY84-11483)Joint Services Electronics Program (Contract DAAG29-83-K-0003)U.S. Navy - Office of Naval Research (Contract NO0014-79-C-0183)U.S. Navy - Office of Naval Research (Contract N00014-83-K-0695)National Science Foundation (Grant PHY83-07172-A01