1,862 research outputs found
Unifying Requirements and Code: an Example
Requirements and code, in conventional software engineering wisdom, belong to
entirely different worlds. Is it possible to unify these two worlds? A unified
framework could help make software easier to change and reuse. To explore the
feasibility of such an approach, the case study reported here takes a classic
example from the requirements engineering literature and describes it using a
programming language framework to express both domain and machine properties.
The paper describes the solution, discusses its benefits and limitations, and
assesses its scalability.Comment: 13 pages; 7 figures; to appear in Ershov Informatics Conference, PSI,
Kazan, Russia (LNCS), 201
Optical study of the anisotropic erbium spin flip-flop dynamics
We investigate the erbium flip-flop dynamics as a limiting factor of the
electron spin lifetime and more generally as an indirect source of decoherence
in rare-earth doped insulators. Despite the random isotropic arrangement of
dopants in the host crystal, the dipolar interaction strongly depends on the
magnetic field orientation following the strong anisotropy of the -factor.
In Er:YSiO, we observe by transient optical spectroscopy a three
orders of magnitude variation of the erbium flip-flop rate (10ppm dopant
concentration). The measurements in two different samples, with 10ppm and 50ppm
concentrations, are well-supported by our analytic modeling of the dipolar
coupling between identical spins with an anisotropic -tensor. The model can
be applied to other rare-earth doped materials. We extrapolate the calculation
to Er:CaWO, Er:LiNbO and Nd:YSiO at
different concentrations
Operational Semantics of Process Monitors
CSPe is a specification language for runtime monitors that can directly
express concurrency in a bottom-up manner that composes the system from
simpler, interacting components. It includes constructs to explicitly flag
failures to the monitor, which unlike deadlocks and livelocks in conventional
process algebras, propagate globally and aborts the whole system's execution.
Although CSPe has a trace semantics along with an implementation demonstrating
acceptable performance, it lacks an operational semantics. An operational
semantics is not only more accessible than trace semantics but also
indispensable for ensuring the correctness of the implementation. Furthermore,
a process algebra like CSPe admits multiple denotational semantics appropriate
for different purposes, and an operational semantics is the basis for
justifying such semantics' integrity and relevance. In this paper, we develop
an SOS-style operational semantics for CSPe, which properly accounts for
explicit failures and will serve as a basis for further study of its
properties, its optimization, and its use in runtime verification
Impact of washing and sterilization on properties of fabrics used for medical applications
This paper reports a study on the characterization of cellulosic, polyester/cotton (PES/cotton) and Tencel fabrics as well as PES/PU/PES laminate used for medical applications, before and after frequent washing and sterilization. The impact of washing and sterilization is analysed by tensile properties, spectral changes and surface characterization. The results indicate that, during washing and sterilization, cellulosic fabrics show prominent changes of all studied properties when compared to PES/PU/PES laminate
Superhyperfine induced photon-echo collapse of erbium in YSiO
We investigate the decoherence of Er in YSiO at low magnetic
fields using the photon-echo technique. We reproduce accurately a variety of
the decay curves with a unique coherence time by considering the so-called
superhyperfine modulation induced by a large number of neighbouring spins.
There is no need to invoke any characteristic time of the spin fluctuations to
reproduce very different decay curves. The number of involved nuclei increases
when the magnetic is lowered. The experiment is compared with a model
associating 100 surrounding ions with their exact positions in the crystal
frame. We also derive an approximate spherical model (angular averaging) to
interpret the main feature the observed decay curves close to zero-field
Protocol for a scoping review on information needs and information-seeking behaviour of people with dementia and their non-professional caregivers
Background: Dementia is a debilitating disease that can lead to major changes in a patient’s behaviour and function. It is important to educate both dementia patients and their non-professional caregivers about the disease. Yet, currently available sources do not seem to be effective for patients and caregivers, who report a need for more information and guidance. A systematic identification of the patients’ and caregivers’ needs for information and information seeking behaviour is needed to create information resources that are relevant and beneficial to the target population. Objective: This is a protocol for a scoping review aimed at gathering knowledge on the information needs and information seeking behaviour of dementia patients and their non- professional caregivers. Our aim is also to provide recommendations for development of future dementia information resources. Methods: The study will commence in November 2018. Both quantitative and qualitative studies on the information needs of dementia patients or caregivers will be examined using Arksey and O’Malley’s methodological framework for scoping studies. A comprehensive literature search will be conducted in electronic databases and grey literature sources. We will also screen reference lists of included studies and related systematic reviews for additional eligible studies. Two authors will perform screening of citations for eligibility, and independently extract data from the included studies in parallel. Any discrepancies will be resolved through discussion. The findings will be presented through a narrative synthesis and reported in line with PRISMA reporting guidelines. Ethics and dissemination: In this review, all included data will originate from published literature. Ethics approval is therefore not a requirement. We will present our findings at relevant conferences and will submit them for publication in peer-reviewed journals. Strengths and limitations of this study • In this scoping review, we will perform a comprehensive search of electronic databases and grey literature sources to identify up-to-date evidence on information needs and information seeking behaviour of dementia patients and their informal caregivers. • We will seek to identify evidence on information needs and information seeking behaviour of both dementia patients and their caregivers. • As this is a scoping review, a formal quality and risk of bias assessment of the included literature will not be performed. • This review will only include studies published in English
Ab initio Molecular Dynamics in Adaptive Coordinates
We present a new formulation of ab initio molecular dynamics which exploits
the efficiency of plane waves in adaptive curvilinear coordinates, and thus
provides an accurate treatment of first-row elements. The method is used to
perform a molecular dynamics simulation of the CO_2 molecule, and allows to
reproduce detailed features of its vibrational spectrum such as the splitting
of the Raman sigma+_g mode caused by Fermi resonance. This new approach opens
the way to highly accurate ab initio simulations of organic compounds.Comment: 11 pages, 3 PostScript figure
Achieving provider engagement: providers' perceptions of implementing and delivering integrated care
The literature on integrated care is limited with respect to practical learning and experience. Although some attention has been paid to organizational processes and structures, not enough is paid to people, relationships, and the importance of these in bringing about integration. Little is known, for example, about provider engagement in the organizational change process, how to obtain and maintain it, and how it is demonstrated in the delivery of integrated care. Based on qualitative data from the evaluation of a large-scale integrated care initiative in London, United Kingdom, we explored the role of provider engagement in effective integration of services. Using thematic analysis, we identified an evolving engagement narrative with three distinct phases: enthusiasm, antipathy, and ambivalence, and argue that health care managers need to be aware of the impact of professional engagement to succeed in advancing the integrated care agenda
Optical properties of the vibrations in charged C molecules
The transition strengths for the four infrared-active vibrations of charged
C molecules are evaluated in self-consistent density functional theory
using the local density approximation. The oscillator strengths for the second
and fourth modes are strongly enhanced relative to the neutral C
molecule, in good agreement with the experimental observation of ``giant
resonances'' for those two modes. Previous theory, based on a ``charged
phonon'' model, predicted a quadratic dependence of the oscillator strength on
doping, but this is not borne out in our calculations.Comment: 10 pages, RevTeX3.
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