Modelling Driver Interdependent Behaviour in Agent-Based Traffic Simulations for Disaster Management

Accurate modelling of driver behaviour in evacuations is vitally important in creating realistic training environments for disaster management. However, few current models have satisfactorily incorporated the variety of factors that affect driver behaviour. In particular, the interdependence of driver behaviours is often seen in real-world evacuations, but is not represented in current state-of-the art traffic simulators. To address this shortcoming, we present an agent-based behaviour model based on the social forces model of crowds. Our model uses utility-based path trees to represent the forces which affect a driver's decisions. We demonstrate, by using a metric of route similarity, that our model is able to reproduce the real-life evacuation behaviour whereby drivers follow the routes taken by others. The model is compared to the two most commonly used route choice algorithms, that of quickest route and real-time re-routing, on three road networks: an artificial "ladder" network, and those of Lousiana, USA and Southampton, UK. When our route choice forces model is used our measure of route similarity increases by 21%-93%. Furthermore, a qualitative comparison demonstrates that the model can reproduce patterns of behaviour observed in the 2005 evacuation of the New Orleans area during Hurricane Katrina

Agent-based Traffic Operator Training Environments for Evacuation Scenarios

Realistic simulation environments play a vital role in the effective training of traffic controllers to respond to large-scale events such as natural disasters or terrorist threats. BAE SYSTEMS is developing a training environment that comprises of: a physical traffic control centre environment, a 3D visualisation and a traffic behaviour model. In this paper, we describe how an agent-based approach has been essential in the development of the traffic operator training environment, especially for constructing the required behavioural models. The simulator has been applied to an evacuation scenario, for which an agent-based model has been developed which models a variety of relevant driver evacuation behaviours. These unusual behaviours have been observed occurring in real-life evacuations but to date have not been incorporated in traffic simulators. In addition, our agent-based approach includes flexibility within the simulator to respond to the variety of decisions traffic controllers can make, as well as achieving a strong degree of control for the scenario manager

The effect of dietary protein source on the metabolism and performance of ewes in late pregnancy and early lactation

Three experiments were carried out to investigate the effects of dietary protein source on the metabolism and performance of straw fed, twin-bearing ewes in late pregnancy and early lactation. In the first experiment, 72 ewes were fed concentrate diets which contained either fishmeal or formaldehyde treated soya-bean meal. The concentrate was either fed alone, or at a reduced rate with feedblocks ad libitum in a two by two factorial design. Ewes fed fishmeal lost more condition after parturition and had lambs which grew quicker than ewes fed treated soya-bean meal (P<0.05). Ewes offered feedblocks produced colostrum with a higher immunoglobulin G (IgG) concentration at birth, had lambs with a higher litter weight than those fed concentrate alone (P<0.05). In the second experiment, 60 ewes were fed concentrates containing either untreated or formaldehyde treated rapeseed meal or field beans in a two by two factorial design with an additional control diet containing fishmeal. Ewes fed fishmeal had a higherpre partum condition score gain and had lambs which grew slower with a lower litter weight at 28 days than ewes fed all other diets. Ewes fed rapeseed meal had a higher total colostrum yield at birth than ewes fed field beans (P<0.05). Ewes fed formaldehyde treated protein sources had a reduced yield of total milk, protein, solids not fat and lactose at 21 days post partum than ewes fed untreated protein sources (P<0.05). In the third experiment, 44 ewes were fed concentrate diets containing either fishmeal, untreated soya-bean meal, formaldehyde treated soya-bean meal or formaldehyde treated soya-bean meal with added rumen protected methionine. Ewes fed formaldehyde treated soya-bean meal with added methionine produced colostrum between 12 and 16 hours post partum with a higher fat concentration and a higher yield of fat and crude protein than ewes fed fishmeal (P<0.05). Ewes fed formaldehyde treated soya-bean meal with added methionine had lambs which grew quicker and were heavier at 28 days of age than those fed fishmeal (P<0.05)

Sterling devaluation: its implications for Rhodesia

A RJE article on the effects of the devaluation of the pound sterling on the then Rhodesian economy and currency.It is interesting to recall the different circumstances surrounding the successive devaluations of the pound sterling. In 1931 the severe unemployment brought on by the great depression was reason enough for the 30 per cent British devaluation. It was hoped that the unemployment centred in the export industries but which had spread throughout the economy, would be eliminated by boosting exports through devaluation. In the event, this hope was not entirely realised and it took the preparation for a world war to completely solve the problem in the U.K. South Africa, initially attempting to maintain the value of her currency in the face of the British action, was forced to follow suit fifteen months later. The serious outflow of speculative funds on capital account, the pressure on agricultural exports and the harmful effects on the gold mining industry made this inevitable

The Utilisation of biomass as a fuel for chemical looping combustion

Development of a commercially viable carbon capture and sequestration (CCS) technology for fossil fuel power generation is vital if the anticipated effects of global warning are to be avoided. Chemical-looping combustion (CLC) is an indirect combustion process that utilises a regenerable solid oxygen sorbent (oxygen carrier, OC), typically a metal oxide, to transfer oxygen from the combustion air to the fuel such that direct contact between air and fuel is avoided. CLC is a variant on an oxy-fuel carbon capture system that offers the potential for a much lower energy penalty as CO2 separation is achieved intrinsically such that additional energy-intensive gas separation steps are avoided. Our research focuses on the development and optimisation of OCs for CLC systems using biomass and biomass derived fuels. The development of a CLC process utilising biomass is of particular interest as it has the potential to result in negative CO2 emissions i.e. a net removal of CO2 from the atmosphere. Thermochemical conversion of biomass typically results in the formation of significant quantities of refractory tar compounds which are difficult to combust and can lead to reduced fuel conversion efficiencies. Decomposition of the tars on the surface of the OC can result in severe coking and temporary deactivation. Coking of the OC also limits the overall CO2 capture efficiency of the process as regeneration of the OC in air produces CO2 which cannot be captured. This thesis documents the progress made towards the development of a robust laboratory based system for testing the effects of biomass tars on the long term performance of a chemical-looping combustion process. The work completed in this thesis can be divided into two main areas: the first involved developing optimised fabrication strategies for the production of inexpensive iron-based oxygen carrier particles of high reactivity and robust physical characteristics that could be used in CLC systems utilising biomass as the fuel. The second research focus involved the development of a reactor and analysis protocol for studying the interactions between biomass pyrolysis tars and the cheap, synthetic iron-based oxygen carrier materials. A range of pure iron oxide and iron oxide supported with 40 wt.% Al2O3 oxygen carrier materials were prepared via simple scalable fabrication techniques based on wet granulation for use in CLC systems utilising biomass or gasified biomass as a fuel. The oxygen carrier particles were subjected to rigorous testing using a range of analytical methods to assess their physical and chemical properties and suitability for use in large-scale systems. The effect of fabrication method and alumina precursor material used for producing the supported iron oxide materials were found to have a considerable effect on the physical characteristics and reactivity of the oxygen carrier material. The reduction kinetics (the rate limiting step in the CLC of gaseous fuels) of the different OC materials prepared in this work were assessed using a thermogravimetric analyser (TGA). A simple particle model based on the concept of effectiveness factor was applied to determine the intrinsic kinetic information. Preparation of the Al2O3 supported iron oxide oxygen carrier material using a Al(OH)3 alumina precursor gave the most porous oxygen carrier material with the highest surface area. This oxygen carrier was also the most reactive particularly at temperatures above 973 K and demonstrated very good thermal stability at temperatures up to 1173 K. The activation energy of the oxygen carrier was found to increase from 73 kJ mol-1 for the temperature range 823-1073 K to 123 kJ mol-1 at temperatures of 1073-1173 K. The increase in the activation energy was attributed to further conversion of Fe3O4 to FeAl2O4 which was more pronounced at the higher temperature range. Here we propose that the formation of FeAl2O4 was beneficial, acting to enhance the thermal stability, reactivity and oxygen transfer capacity of the iron oxide based oxygen carrier material. A new 500W laboratory-scale, two-stage fixed-bed reactor for simulating CLC with ex situ solid fuel gasification has been designed and constructed. Preliminary studies of the interactions between OC materials consisting of pure iron oxide and 60 wt.% Fe2O3 iron oxide supported on Al2O3 and a gas stream produced from the pyrolysis of biomass to emulate a fuel gas containing large quantities of tars were carried out. The presence of both OC materials at 973 K was found to significantly reduce the amount of biomass tars by up to 71 wt.% in the case of the 60 wt.% Fe2O3/40 wt.% Al2O3 OC material compared with analogous experiments in which the biomass tars were exposed to an inert bed of sand. Exposing the pyrolysis vapours to the oxygen carriers in their oxidised form favoured the production of CO2. The production of CO was favoured when the oxygen carriers were in their reduced forms. Both oxygen carrier materials were affected by carbon deposition. Carbon deposition was removed in the subsequent oxidation phase with no obvious deleterious effects on the reactivity of the oxygen carrier materials after exposure to the pyrolysis gases and vapours.Open Acces

The Basic Course: A Means of Protecting the Speech Communication Discipline

During the summer of 1995, Spectra included articles and news items regarding speech communication programs designated for elimination. Some leaders in the discipline warned that this trend would likely continue. This article argues that departments of communication, operating under federal and state requirements for communication competency, may be well advised to work toward establishing the basic course as the sole fulfillment of their institutions\u27 core requirement in communication and to plan a marketing strategy for their discipline. In addition, this paper suggests that the basic course, taught as public speaking, may be more easily defended in meeting the course requirement, as opposed to the hybrid course and other courses within that discipline

Lower Permian facies of the Palo Duro Basin, Texas : depositional systems, shelf-margin evolution, paleogeography, and petroleum potential

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