883 research outputs found
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Does the threat of disqualification deter drivers from speeding?
Road Safety Research Report, number 96, is available from the National Archives: Department for Transport, and can be accessed from the link below.It has long been recognised that driving speeds that are excessive and inappropriate
to the conditions are a major contributory factor in road accidents, and a major issue
for road safety. Restraining driving speeds has proved to be a difficult task, given the
improvements over the years in both vehicle performance and road design.
Within the traditional âthree Esâ countermeasures of engineering, education and
enforcement, recent years have seen the introduction of a wide range of engineering
measures designed to bring about speed reduction, but these tend to be restricted to
specific parts of the road network. New technologies such as Intelligent Speed
Adaptation (ISA) offer considerable promise, but mainly in the medium or longer term. Similarly, educative efforts to induce attitude and behaviour change in this context are bearing fruit, yet this is a long-term rather than short-term project. For the foreseeable future, enforcement will remain the principal means of influencing speed, by setting speed limits and imposing sanctions on drivers who are caught exceeding them.
The number of licence endorsements has increased enormously in recent years.
However, over the same period the number of disqualifications resulting from âtotting-upâ points has decreased. This would seem to indicate that many drivers who accumulate up to 11 penalty points are either acting as if deterred by the threat of disqualification, or are avoiding disqualification in some other way. The extent to which penalty points act as a deterrent for the benefit of road safety in general is therefore an important issue, and this report describes work that has been carried out to study this issue by TRL and Brunel University, under contract to the Department for Transport
Exploring the needs of military children in public schools: What school psychologists need to know
Although research has been published documenting the increased risk for negative social, emotional, behavioral, and academic outcomes of military-connected students, no research prior to this study has given voice to these students and explored their experiences and needs. Five military-connected high school students participated in a focus group exploring what their lived experiences are in the context of living in a military-connected home and what they wish their schools knew to better support them. A thematic analysis was used to analyze the qualitative data and six themes emerged from the discussion: the emotional burden these students carry, distance they feel from their parent serving, pressure to succeed, the desire for visibility within their schools, going home to more than homework, and the instability and unknow of military life. These themes can provide a framework for schools to develop a multi-tiered system of support to ensure military-connected students are seen, heard, and supported at every transition. School psychologists can utilize these themes to advocate for military-connected students and support their needs with their unique knowledge of both the psychological and academic demands placed on student
BPS Quivers of Five-Dimensional SCFTs, Topological Strings and q-Painlevé Equations
We study the discrete flows generated by the symmetry group of the BPS quivers for CalabiâYau geometries describing five-dimensional superconformal quantum field theories on a circle. These flows naturally describe the BPS particle spectrum of such theories and at the same time generate bilinear equations of q-difference type which, in the rank one case, are q-PainlevĂ© equations. The solutions of these equations are shown to be given by grand canonical topological string partition functions which we identify with Ï-functions of the cluster algebra associated to the quiver. We exemplify our construction in the case corresponding to five-dimensional SU(2) pure super YangâMills and Nf= 2 on a circle
Harvesting, coupling and control of single exciton coherences in photonic waveguide antennas
We perform coherent non-linear spectroscopy of individual excitons strongly
confined in single InAs quantum dots (QDs). The retrieval of their
intrinsically weak four-wave mixing (FWM) response is enabled by a
one-dimensional dielectric waveguide antenna. Compared to a similar QD embedded
in bulk media, the FWM detection sensitivity is enhanced by up to four orders
of magnitude, over a broad operation bandwidth. Three-beam FWM is employed to
investigate coherence and population dynamics within individual QD transitions.
We retrieve their homogenous dephasing in a presence of spectral wandering.
Two-dimensional FWM reveals off-resonant F\"orster coupling between a pair of
distinct QDs embedded in the antenna. We also detect a higher order QD
non-linearity (six-wave mixing) and use it to coherently control the FWM
transient. Waveguide antennas enable to conceive multi-color coherent
manipulation schemes of individual emitters.Comment: 7 pages, 8 Figure
Can DSM-5 Differentiate between Non-Pathological Possession and Dissociative Identity Disorder? A Case Study from an Afro-Brazilian Religion
Antireflective photonic structure for coherent nonlinear spectroscopy of single magnetic quantum dots
This work presents epitaxial growth and optical spectroscopy of CdTe quantum
dots (QDs) in (Cd,Zn,Mg)Te barriers placed on the top of (Cd,Zn,Mg)Te
distributed Bragg reflector. The formed photonic mode in our half-cavity
structure permits to enhance the local excitation intensity and extraction
efficiency of the QD photoluminescence, while suppressing the reflectance
within the spectral range covering the QD transitions. This allows to perform
coherent, nonlinear, resonant spectroscopy of individual QDs. The coherence
dynamics of a charged exciton is measured via four-wave mixing, with the
estimated dephasing time ps. The same structure contains
QDs doped with single Mn ions, as detected in photoluminescence spectra.
Our work therefore paves the way toward investigating and controlling an
exciton coherence coupled, via ,- exchange interaction, with an
individual spin of a magnetic dopant.Comment: 6 pages, 5 figure
CHARM facility remotely controlled platform at CERN: A new fault-tolerant redundant architecture
Many power electronics applications require high tolerance to faults such as short circuit or open circuit of the control signals. One such application is the CERN High energy AcceleRator Mixed-field (CHARM) facility, where maintenance may be precluded for long periods of time due to radiation and, therefore, high reliability is necessary.
A redundant interconnection architecture for the control signals is proposed, where each signal is individually processed by different CPUs and transmitted through separate interconnection lines. During normal operation, the CPUs are synchronized and produce the same signals. The purpose of the proposed hardware and firmware strategy is to allow the actuator to continue operating even in case of fault; regardless of the fault type (open circuit, short circuit to ground or to positive supply), a fault on one of the parallel lines would not inhibit the correct operation of the remaining line.
This solution can be used to control the movements of a target system using a remote joystick in a safe environment. The architecture features reliable transmission of PWM signals driving a half-bridge power converter.
Moreover, it is possible to extend it to any type of converter such as three-phase bridges, three-level NPC, or buck-boost converters.
Simulations and experimental results show a good agreement, proving the effectiveness of the proposed fault tolerant circuitry
A Logical Form Parser for Correction and Consistency Checking of LF resources
In this paper we present ongoing work for the correction of Extended
WordNet (XWN), the most extended freely downloadable resource of Logical
Forms (LFs) â by the Human Language Technology Research Institute
(HLTRI) of University of Texas at Dallas (UTD). In a previous paper we reported
on type and number of errors detected in the 140,000 entries of the resource,
which amounted to some 30%. This didnât include problems related to
inconsistencies from disconnected variables which were not computable at the
time. We now created an LF parser that parses each entry after appropriate
transformations. The parser has been created to count the number of disconnected
variables, be they object variables or predicate event variables: the result
is 56% of LFs containing some disconnected variable. We devised two procedures
for correction: one lexical and the other structural which eventually allowed
a dramatic reduction: the final count is now 24%. Additional work has
been carried out to improve the general consistency by manual intervention on
"inconsistent" outputs signaled by the parser and has reduce the number of errors
to a reasonable percentage for such a resource, that is less that 15%
Impact of phonons on dephasing of individual excitons in deterministic quantum dot microlenses
Optimized light-matter coupling in semiconductor nanostructures is a key to
understand their optical properties and can be enabled by advanced fabrication
techniques. Using in-situ electron beam lithography combined with a
low-temperature cathodoluminescence imaging, we deterministically fabricate
microlenses above selected InAs quantum dots (QDs) achieving their efficient
coupling to the external light field. This enables to perform four-wave mixing
micro-spectroscopy of single QD excitons, revealing the exciton population and
coherence dynamics. We infer the temperature dependence of the dephasing in
order to address the impact of phonons on the decoherence of confined excitons.
The loss of the coherence over the first picoseconds is associated with the
emission of a phonon wave packet, also governing the phonon background in
photoluminescence (PL) spectra. Using theory based on the independent boson
model, we consistently explain the initial coherence decay, the zero-phonon
line fraction, and the lineshape of the phonon-assisted PL using realistic
quantum dot geometries
A computational approach to implicit entities and events in text and discourse
In this paper we will focus on the notion of âimplicitâ
or lexically unexpressed linguistic elements that are
nonetheless necessary for a complete semantic interpretation
of a text. We refer to âentitiesâ and âeventsâ because
the recovery of the implicit material may affect all the modules
of a system for semantic processing, from the grammatically
guided components to the inferential and reasoning
ones. Reference to the system GETARUNS offers one possible
implementation of the algorithms and procedures needed
to cope with the problem and enables us to deal with all the
spectrum of phenomena. The paper will address at first the
following three types of âimplicitâ entities and events:
â the grammatical ones, as suggested by a linguistic theories
like LFG or similar generative theories;
â the semantic ones suggested in the FrameNet project, i.e.
CNI, DNI, INI;
â the pragmatic ones: here we will present a theory and an
implementation for the recovery of implicit entities and
events of (non-) standard implicatures.
In particular we will show how the use of commonsense
knowledge may fruitfully contribute to find relevant implied
meanings. Last Implicit Entity only touched on, though for
lack of space, is the Subject of Point of View, which is computed
by Semantic Informational Structure and contributes
the intended entity from whose point of view a given subjective
statement is expressed
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