530 research outputs found
An active-architecture approach to COTS integration
Commercial off-the-shelf (COTS) software products are increasingly used as standard components within integrated information systems. This creates challenges since both their developers and source code are not usually available, and the ongoing development of COTS cannot be predicted. The ArchWare Framework approach recognises COTS products as part of the ambient environment of an information system and therefore an important part of development is incorporating COTS as effective system components. This integration of COTS components, and the composition of components, is captured by an active architecture model which changes as the system evolves. Indeed the architecture modelling language used enables it to express the monitoring and evolution of a system. This active architecture model is structured using control system principles. By modelling both integration and evolution it can guide the system’s response to both predicted and emergent changes that arise from the use of COTS products.Publisher PDFPeer reviewe
Black Hole - Never Forms, or Never Evaporates
Many discussion about the black hole conundrums, such as singularity and
information loss, suggested that there must be some essential irreconcilable
conflict between quantum theory and classical gravity theory, which cannot be
solved with any semiclassical quantized model of gravity, the only feasible way
must be some complete unified quantum theory of gravity.
In \cite{Vachaspati2007a}, the arguments indicate the possibility of an
alternate outcome of gravitational collapse which avoids the information loss
problem. In this paper, also with semiclassical analysis, it shows that so long
as the mechanism of black hole evaporation satisfies a quite loose condition
that the evaporation lifespan is finite for external observers, regardless of
the detailed mechanism and process of evaporation, the conundrums above can be
naturally avoided. This condition can be satisfied with Hawking-Unruh
mechanism. Thus, the conflict between quantum theory and classical gravity
theory may be not as serious as it seemed to be, the effectiveness of
semiclassical methods might be underestimated.
An exact universal solution with spherical symmetry of Einstein field
equation has been derived in this paper. All possible solutions with spherical
symmetry of Einstein field equation are its special cases.
In addition, some problems of the Penrose diagram of an evaporating black
hole first introduced by Hawking in 1975 \cite{Hawking1975} are clarified.Comment: 17 pages, 7 figures. Compared to the published version in JCAP, some
minimal typeset error has been correcte
Life path analysis: scaling indicates priming effects of social and habitat factors on dispersal distances
1. Movements of many animals along a life-path can be separated into repetitive ones within home ranges and transitions between home ranges. We sought relationships of social and environmental factors with initiation and distance of transition movements in 114 buzzards Buteo buteo that were marked as nestlings with long-life radio tags.
2. Ex-natal dispersal movements of 51 buzzards in autumn were longer than for 30 later in their first year and than 35 extra-natal movements between home ranges after leaving nest areas. In the second and third springs, distances moved from winter focal points by birds that paired were the same or less than for unpaired birds. No post-nuptial movement exceeded 2 km.
3. Initiation of early ex-natal dispersal was enhanced by presence of many sibs, but also by lack of worm-rich loam soils. Distances travelled were greatest for birds from small broods and with relatively little short grass-feeding habitat near the nest. Later movements were generally enhanced by the absence of loam soils and short grassland, especially with abundance of other buzzards and probable poor feeding habitats (heathland, long grass).
4. Buzzards tended to persist in their first autumn where arable land was abundant, but subsequently showed a strong tendency to move from this habitat.
5. Factors that acted most strongly in ½-km buffers round nests, or round subsequent focal points, usually promoted movement compared with factors acting at a larger scale. Strong relationships between movement distances and environmental characteristics in ½-km buffers, especially during early ex-natal dispersal, suggested that buzzards became primed by these factors to travel far.
6. Movements were also farthest for buzzards that had already moved far from their natal nests, perhaps reflecting genetic predisposition, long-term priming or poor habitat beyond the study area
Parasitic helminth infections and the control of human allergic and autoimmune disorders
The profile of global health today presents a striking reciprocal distribution between parasitic diseases in many of the world’s lower-income countries, and ever-increasing levels of inflammatory disorders such as allergy, autoimmunity and inflammatory bowel diseases in the more affluent societies. Attention is particularly focused on helminth worm parasites, which are associated with protection from allergy and inflammation in both epidemiological and laboratory settings. One mechanistic explanation of this is that helminths drive the regulatory arm of the immune system, abrogating the ability of the host to expel the parasites, while also dampening reactivity to many “bystander” specificities. Interest has therefore heightened into whether helminth parasites, or their products, hold therapeutic potential for immunological disorders of the developed world. In this narrative review, progress across a range of trials is discussed, together with prospects for isolating individual molecular mediators from helminths that may offer defined new therapies for inflammatory conditions
Frame Theory for Signal Processing in Psychoacoustics
This review chapter aims to strengthen the link between frame theory and
signal processing tasks in psychoacoustics. On the one side, the basic concepts
of frame theory are presented and some proofs are provided to explain those
concepts in some detail. The goal is to reveal to hearing scientists how this
mathematical theory could be relevant for their research. In particular, we
focus on frame theory in a filter bank approach, which is probably the most
relevant view-point for audio signal processing. On the other side, basic
psychoacoustic concepts are presented to stimulate mathematicians to apply
their knowledge in this field
Towards new material biomarkers for fracture risk
Osteoporosis is a prevalent bone condition, characterised by low bone mass and increased fracture risk. Currently, the gold standard for identifying osteoporosis and increased fracture risk is through quantification of bone mineral density (BMD) using dual energy X-ray absorption (DEXA). However, the risk of osteoporotic fracture is determined collectively by bone mass, architecture and physicochemistry of the mineral composite building blocks. Thus DEXA scans alone inevitably fail to fully discriminate individuals who will suffer a fragility fracture. This study examines trabecular bone at both ultrastructure and microarchitectural levels to provide a detailed material view of bone, and therefore provides a more comprehensive explanation of osteoporotic fracture risk. Physicochemical characterisation obtained through X-ray diffraction and infrared analysis indicated significant differences in apatite crystal chemistry and nanostructure between fracture and non-fracture groups. Further, this study, through considering the potential correlations between the chemical biomarkers and microarchitectural properties of trabecular bone, has investigated the relationship between bone mechanical properties (e.g. fragility) and physicochemical material features
General psychopathology, internalising and externalising in children and functional outcomes in late adolescence
Background: Internalising and externalising problems commonly co-occur in childhood. Yet, few developmental
models describing the structure of child psychopathology appropriately account for this comorbidity. We evaluate a
model of childhood psychopathology that separates the unique and shared contribution of individual psychological
symptoms into specific internalising, externalising and general psychopathology factors and assess how these
general and specific factors predict long-term outcomes concerning criminal behaviour, academic achievement and
affective symptoms in three independent cohorts. Methods: Data were drawn from independent birth cohorts (Avon
Longitudinal Study of Parents and Children (ALSPAC), N = 11,612; Generation R, N = 7,946; Maternal Adversity,
Vulnerability and Neurodevelopment (MAVAN), N = 408). Child psychopathology was assessed between 4 and
8 years using a range of diagnostic and questionnaire-based measures, and multiple informants. First, structural
equation models were used to assess the fit of hypothesised models of shared and unique components of
psychopathology in all cohorts. Once the model was chosen, linear/logistic regressions were used to investigate
whether these factors were associated with important outcomes such as criminal behaviour, academic achievement
and well-being from late adolescence/early adulthood. Results: The model that included specific factors for
internalising/externalising and a general psychopathology factor capturing variance shared between symptoms
regardless of their classification fits well for all of the cohorts. As hypothesised, general psychopathology factor scores
were predictive of all outcomes of later functioning, while specific internalising factor scores predicted later
internalising outcomes. Specific externalising factor scores, capturing variance not shared by any other psychological
symptoms, were not predictive of later outcomes. Conclusions: Early symptoms of psychopathology carry
information that is syndrome-specific as well as indicative of general vulnerability and the informant reporting on
the child. The ‘general psychopathology factor’ might be more relevant for long-term outcomes than specific
symptoms. These findings emphasise the importance of considering the co-occurrence of common internalising and
externalising problems in childhood when considering long-term impact
Improved W boson mass measurement with the D0 detector
We have measured the W boson mass using the D0 detector and a data sample of
82 pb^-1 from the Tevatron collider. This measurement used W -> e nu decays,
where the electron is close to a boundary of a central electromagnetic
calorimeter module. Such 'edge' electrons have not been used in any previous D0
analysis, and represent a 14% increase in the W boson sample size. For these
electrons, new response and resolution parameters are determined, and revised
backgrounds and underlying event energy flow measurements are made. When the
current measurement is combined with previous D0 W boson mass measurements, we
obtain M_W = 80.483 +/- 0.084 GeV. The 8% improvement from the previous D0
measurement is primarily due to the improved determination of the response
parameters for non-edge electrons using the sample of Z bosons with non-edge
and edge electrons.Comment: submitted to Phys. Rev. D; 20 pages, 18 figures, 9 table
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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