2,770 research outputs found
Smart driving aids and their effects on driving performance and driver distraction
In-vehicle information systems have been shown to increase driver workload and cause distraction; both of which are causal factors for accidents. This simulator study evaluates the impact that two designs for a smart driving aid, and scenario complexity have on workload, distraction and driving performance. Results showed that real-time delivery of smart driving information did not increase driver workload or adversely effect driver distraction, while having the effect of decreasing mean driving speed in both the simple and complex driving scenarios. Subjective workload was shown to increase with task difficulty, as well as revealing important differences between the two interface designs
Smart driving assistance systems : designing and evaluating ecological and conventional displays
In-vehicle information systems have been shown to increase driver workload and cause distraction;
both are causal factors for accidents. This simulator study evaluates the impact that two designs for
a smart driving aid and scenario complexity has on workload, distraction and driving performance.
Results showed that real-time delivery of smart driving information did not increase driver workload
or adversely affect driver distraction, while having the effect of decreasing mean driving speed
in both the simple and complex driving scenarios. Important differences were also highlighted
between conventional and ecologically designed smart driving interfaces with respect to subjective
workload and peripheral detection
Quantum Corrections in Quintessence Models
We investigate the impact of quantum fluctuations on a light rolling
quintessence field from three different sources, namely, from a coupling to the
standard model and dark matter, from its self-couplings and from its coupling
to gravity. We derive bounds for time-varying masses from the change of vacuum
energy, finding \Delta m_e/m_e << 10^{-11} for the electron and \Delta m_p/m_p
<< 10^{-15} for the proton since redshift z~2, whereas the neutrino masses
could change of order one. Mass-varying dark matter is also constrained. Next,
the self-interactions are investigated. For inverse power law potentials, the
effective potential does not become infinitely large at small field values, but
saturates at a finite maximal value. We discuss implications for cosmology.
Finally, we show that one-loop corrections induce non-minimal gravitational
couplings involving arbitrarily high powers of the curvature scalar R,
indicating that quintessence entails modified gravity effects.Comment: 10 pages + appendix, added reference
A homogenization theorem for Langevin systems with an application to Hamiltonian dynamics
This paper studies homogenization of stochastic differential systems. The
standard example of this phenomenon is the small mass limit of Hamiltonian
systems. We consider this case first from the heuristic point of view,
stressing the role of detailed balance and presenting the heuristics based on a
multiscale expansion. This is used to propose a physical interpretation of
recent results by the authors, as well as to motivate a new theorem proven
here. Its main content is a sufficient condition, expressed in terms of
solvability of an associated partial differential equation ("the cell
problem"), under which the homogenization limit of an SDE is calculated
explicitly. The general theorem is applied to a class of systems, satisfying a
generalized detailed balance condition with a position-dependent temperature.Comment: 32 page
Quantum Dynamics for de Sitter Radiation
We revisit the Hamiltonian formalism for a massive scalar field and study the
particle production in a de Sitter space. In the invariant-operator picture the
time-dependent annihilation and creation operators are constructed in terms of
a complex solution to the classical equation of motion for the field and the
Gaussian wave function for each Fourier mode is found which is an exact
solution to the Schr\"odinger equation. The in-out formalism is reformulated by
the annihilation and creation operators and the Gaussian wave functions. The de
Sitter radiation from the in-out formalism differs from the Gibbons-Hawking
radiation in the planar coordinates, and we discuss the discrepancy of the
particle production by the two methodComment: LaTex 12 pages, no figure; CosPA2011, Peking Univ., Oct. 28-31, 2011;
references added; to be published in International Journal of Modern Physics:
Conference Serie
Exactly Solvable BCS-BEC crossover Hamiltonians
We demonstrate a novel approach that allows the determination of very general
classes of exactly solvable Hamiltonians via Bethe ansatz methods. This
approach combines aspects of both the co-ordinate Bethe ansatz and algebraic
Bethe ansatz. The eigenfunctions are formulated as factorisable operators
acting on a suitable reference state. Yet, we require no prior knowledge of
transfer matrices or conserved operators. By taking a variational form for the
Hamiltonian and eigenstates we obtain general exact solvability conditions. The
procedure is conducted in the framework of Hamiltonians describing the
crossover between the low-temperature phenomena of superconductivity, in the
Bardeen-Cooper-Schrieffer (BCS) theory, and Bose-Einstein condensation (BEC).Comment: 6 Pages, To appear in Proceedings of The XXIXth International
Colloquium on Group-Theoretical Methods in Physics at Chern Institute of
Mathematic
Ecological interface design for eco-driving
Eco-driving issues are of high priority at the moment. Research suggests that a change in driving style can reduce fuel consumption and emissions by around 15% in many cases. In response to this need, the UK Foot-LITE project developed an in-car feedback system to encourage safer and greener driving behaviours. In order
to balance positive behaviour change against the potential negative effects of distraction, an Ecological Interface Design approach was adopted. The current paper presents an overview of the humancentred
design process adopted in the Foot-LITE project, as well as a review of other similar systems on the market
Designing an Adaptive Interface: Using Eye Tracking to Classify How Information Usage Changes Over Time in Partially Automated Vehicles
While partially automated vehicles can provide a range of benefits, they also bring about new Human Machine Interface (HMI) challenges around ensuring the driver remains alert and is able to take control of the vehicle when required. While humans are poor monitors of automated processes, specifically during ‘steady state’ operation, presenting the appropriate information to the driver can help. But to date, interfaces of partially automated vehicles have shown evidence of causing cognitive overload. Adaptive HMIs that automatically change the information presented (for example, based on workload, time or physiologically), have been previously proposed as a solution, but little is known about how information should adapt during steady-state driving. This study aimed to classify information usage based on driver experience to inform the design of a future adaptive HMI in partially automated vehicles. The unique feature of this study over existing literature is that each participant attended for five consecutive days; enabling a first look at how information usage changes with increasing familiarity and providing a methodological contribution to future HMI user trial study design. Seventeen participants experienced a steady-state automated driving simulation for twenty-six minutes per day in a driving simulator, replicating a regularly driven route, such as a work commute. Nine information icons, representative of future partially automated vehicle HMIs, were displayed on a tablet and eye tracking was used to record the information that the participants fixated on. The results found that information usage did change with increased exposure, with significant differences in what information participants looked at between the first and last trial days. With increasing experience, participants tended to view information as confirming technical competence rather than the future state of the vehicle. On this basis, interface design recommendations are made, particularly around the design of adaptive interfaces for future partially automated vehicles
Safe driving in a green world : a review of driver performance benchmarks and technologies to support ‘smart’ driving
Road transport is a significant source of both safety and environmental concerns. With climate change and fuel prices increasingly prominent on social and political agendas, many drivers are turning their thoughts to fuel efficient or ‘green’ (i.e., environmentally friendly) driving practices. Many vehicle manufacturers are satisfying this demand by offering green driving feedback or advice tools. However, there is a legitimate concern regarding the effects of such devices on road safety – both from the point of view of change in driving styles, as well as potential distraction caused by the in-vehicle feedback. In this paper, we appraise the benchmarks for safe and green driving, concluding that whilst they largely overlap, there are some specific circumstances in which the goals are in conflict. We go on to review current and emerging in-vehicle information systems which purport to affect safe and/or green driving, and discuss some fundamental ergonomics principles for the design of such devices. The results of the review are being used in the Foot-LITE project, aimed at developing a system to encourage ‘smart’ – that is safe and green – driving
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