The Leeds Advanced Driving Simulator: Three Years In Operation

The Leeds Advanced Driving Simulator (LADS) at the University of Leeds is a medium cost fixed-base simulator and its development has been funded by the Science and Engineering Research Council (now EPSRC). It has been fully operational since mid-1993 for rural-road scenes (Carsten and Gallimore, 1993) but currently simulation of urban environments and vehicle interactions are possible too. This paper focuses on the recent development of LADS. Also detailed other recent research projects carried out in the simulator to date

The Leeds Advanced Driving Simulator: Three Years In Operation

The Leeds Advanced Driving Simulator (LADS) at the University of Leeds is a medium cost fixed-base simulator and its development has been funded by the Science and Engineering Research Council (now EPSRC). It has been fully operational since mid-1993 for rural-road scenes (Carsten and Gallimore, 1993) but currently simulation of urban environments and vehicle interactions are possible too. This paper focuses on the recent development of LADS. Also detailed other recent research projects carried out in the simulator to date

A Survey of Driving Research Simulators Around the World.

The literature review is part of the EPSRC funded project "Driver performance in the EPSRC driving simulator: a validation study". The aim of the project is to validate this simulator, located at the Department of Psychology, University of Leeds, and thereby to indicate the strengths and weaknesses of the existing configuration. It will provide guidance on how the simulator can be modified and overcome any deficiencies that are detected and also provide "benchmarks" against which other simulators can be compared. The literature review will describe the technical characteristics of the most well-known driving simulators around the world, their special features and their application areas until today. The simulators will be described and compared according to their cost (low, medium and high) and also contact addresses and photographs of the simulators will be provided by the end of the paper. In the process of gathering this information, it became apparent that there are mainly two types of papers published - either in journals or in proceedings from conferences: those describing only the technical characteristics of a specific simulator and those referring only to the applications of a specific simulator. For the first type of papers, the level of detail, format and content varies significantly where for the second one it has been proven extremely difficult to find any information about the technical characteristics of the simulator where the study had been carried out. A number of details provided in this paper are part of personal communication, or personal visits to those particular driving simulator centres or from the World Wide Web. It should also be noted here that most of the researchers contacted here offered very detail technical characteristics and application areas of their driving simulators and the author is grateful to them

Driving Simulator Validation Studies: A Literature Review.

This literature review is part of the "Driver performance in the EPSRC driving simulator: a validation study" project funded by EPSRC. It focuses mainly on driving simulator validation studies with regard to driver behaviour. Various approaches, methodologies and criteria have been proposed until today regarding the behavioral and physical validation of a driving simulator. At the same time, a number of behavioural validation studies have been conducted, with or without taking into account the proposed validation approaches. The author considered necessary this literature review because according to her knowledge there was no other published review which examined thoroughly the link between theory (proposed validation approaches and methodologies) and practice (validation studies cc driving simulators). Most of the recent behaviour validation studies have been focused on the absolute and relative validity of the simulator without taking into consideration the issue of the face validity. The format of this paper will be as follows. A small introduction to driving simulators and their usefulness will be presented first followed by the necessity of validating them. The existing validation approaches, methodologies and criteria will be analysed and earlier and recent behaviour validation studies will be reviewed and compared in detail. These studies will be classified according to the driver behaviour levels and driving performance (as they will be defined) and then will be assessed according to the validation criteria. Emphasis will be given to the interpretation of the findings from these comparisons, and in particular to their applicability in real road traffic situations

Real-time simulation of three-dimensional shoulder girdle and arm dynamics

Electrical stimulation is a promising technology for the restoration of arm function in paralyzed individuals. Control of the paralyzed arm under electrical stimulation, however, is a challenging problem that requires advanced controllers and command interfaces for the user. A real-time model describing the complex dynamics of the arm would allow user-in-the-loop type experiments where the command interface and controller could be assessed. Real-time models of the arm previously described have not included the ability to model the independently controlled scapula and clavicle, limiting their utility for clinical applications of this nature. The goal of this study therefore was to evaluate the performance and mechanical behavior of a real-time, dynamic model of the arm and shoulder girdle. The model comprises seven segments linked by eleven degrees of freedom and actuated by 138 muscle elements. Polynomials were generated to describe the muscle lines of action to reduce computation time, and an implicit, first-order Rosenbrock formulation of the equations of motion was used to increase simulation step-size. The model simulated flexion of the arm faster than real time, simulation time being 92% of actual movement time on standard desktop hardware. Modeled maximum isometric torque values agreed well with values from the literature, showing that the model simulates the moment-generating behavior of a real human arm. The speed of the model enables experiments where the user controls the virtual arm and receives visual feedback in real time. The ability to optimize potential solutions in simulation greatly reduces the burden on the user during development

Stable Radio Frequency Dissemination With Phase Conjugation

Fiber-optic frequency transfer is a promising option for stable and long-distance radio frequency (RF) transmission. This paper consists on a proposed operation principle and simulation of a stable frequency dissemination scheme using photonic microwave phase conjugation2020/202

The stellar populations of the central region of M31

We continue the analysis of the dataset of our spectroscopic observation campaign of M31, by deriving simple stellar population properties (age metallicity and alpha-elements overabundance) from the measurement of Lick/IDS absorption line indices. We describe their two-dimensional maps taking into account the dust distribution in M31. 80\% of the values of our age measurements are larger than 10 Gyr. The central 100 arcsec of M31 are dominated by the stars of the classical bulge of M31. They are old (11-13 Gyr), metal-rich (as high as [Z/H]~0.35 dex) at the center with a negative gradient outwards and enhanced in alpha-elements ([alpha/Fe]~ 0.28+- 0.01 dex). The bar stands out in the metallicity map, where an almost solar value of [Z/H] (~0.02+-0.01 dex) with no gradient is observed along the bar position angle (55.7 deg) out to 600 arcsec from the center. In contrast, no signature of the bar is seen in the age and [alpha/Fe] maps, that are approximately axisymmetric, delivering a mean age and overabundance for the bar and the boxy-peanut bulge of 10-13 Gyr and 0.25-0.27 dex, respectively. The boxy/peanut-bulge has almost solar metallicity (-0.04+- 0.01 dex). The mass-to-light ratio of the three components is approximately constant at M/LV ~ 4.4-4.7 Msol/Lsol. The disk component at larger distances is made of a mixture of stars, as young as 3-4 Gyr, with solar metallicity and smaller M/LV (~3+-0.1 Msol/Lsol). We propose a two-phase formation scenario for the inner region of M31, where most of the stars of the classical bulge come into place together with a proto-disk, where a bar develops and quickly transforms it into a boxy-peanut bulge. Star formation continues in the bulge region, producing stars younger than 10 Gyr, in particular along the bar, enhancing its metallicity. The disk component appears to build up on longer time-scales.Comment: Language-edited version, Accepted for publication in A&

Life and death of a hero - Lessons learned from modeling the dwarf spheroidal Hercules: an incorrect orbit?

Hercules is a dwarf spheroidal satellite of the Milky Way, found at a distance of about 138 kpc, and showing evidence of tidal disruption. It is very elongated and exhibits a velocity gradient of 16 +/- 3 km/s/kpc. Using this data a possible orbit of Hercules has previously been deduced in the literature. In this study we make use of a novel approach to find a best fit model that follows the published orbit. Instead of using trial and error, we use a systematic approach in order to find a model that fits multiple observables simultaneously. As such, we investigate a much wider parameter range of initial conditions and ensure we have found the best match possible. Using a dark matter free progenitor that undergoes tidal disruption, our best-fit model can simultaneously match the observed luminosity, central surface brightness, effective radius, velocity dispersion, and velocity gradient of Hercules. However, we find it is impossible to reproduce the observed elongation and the position angle of Hercules at the same time in our models. This failure persists even when we vary the duration of the simulation significantly, and consider a more cuspy density distribution for the progenitor. We discuss how this suggests that the published orbit of Hercules is very likely to be incorrect.Comment: accepted by MNRAS; 19 pages, 19 figures, 2 table

Population dynamics of Staphylococcus aureus and Salmonella Typhimurium in a laboratory medium and rocket extract

In the present study, the growth of Staphylococcus aureus and Salmonella Typhimurium on different growth media was studied. For this purpose, a growth medium (Luria – Bertani broth, LB) and extract from rocket, were inoculated with Staphylococcus aureus strain COL (MRSA) and Salmonella Typhimurium (CDC 6516-60). After the inoculation, the samples were incubated at 20°C

Single-cell growth kinetic behavior of pathogenic bacteria in the presence of microbial supernatants containing autoinducer-2 signal compounds

The findings of this study constitute preliminary data on the role of QS compounds on the single-cell growth behavior of important pathogens, knowledge that maybe useful in understanding the mechanisms underlying their behavior as well as in developing strategies for their control in situ