7,184 research outputs found
Properties of iterative Monte Carlo single histogram reweighting
We present iterative Monte Carlo algorithm for which the temperature variable
is attracted by a critical point. The algorithm combines techniques of single
histogram reweighting and linear filtering. The 2d Ising model of ferromagnet
is studied numerically as an illustration. In that case, the iterations
uncovered stationary regime with invariant probability distribution function of
temperature which is peaked nearly the pseudocritical temperature of specific
heat. The sequence of generated temperatures is analyzed in terms of stochastic
autoregressive model. The error of histogram reweighting can be better
understood within the suggested model. The presented model yields a simple
relation, connecting variance of pseudocritical temperature and parameter of
linear filtering.Comment: 3 figure
Localization of off-stress-induced damage in AlGaN/GaN high electron mobility transistors by means of low frequency 1/f noise measurements
Experiences of using a wearable camera to record activity, participation and health-related behaviours: Qualitative reflections of using the Sensecam
Objective: Upcoming technology is changing the way that we are able to collect data looking into activity, social participation and health behaviours. Wearable cameras are one form of technology that allows us to automatically record a collection of passive images, building a visual diary of the userâs day. Whilst acknowledging the usefulness of wearable cameras in research, it is also important to understand individualsâ experiences whilst using them. The aim of this study was to explore the acceptance, experience and usability of a wearable camera (Microsoft_ Sensecam) to record the day-to-day activity and social participation of older people. Methods: A total of 18 older adults, who had worn the wearable camera for seven days, took part in semi-structured interviews. Results: Four themes emerged from the findings: âIntrusivenessâ; âImportance of othersâ; âRemembering the wearable cameraâ; and âEase of useâ. Conclusions: Individualsâ expectations and experiences of using the wearable camera differed considerably. Participants believed that the wearable camera would be intrusive, difficult to use and would evoke public reaction; however, these worries were not borne out in experience. Individuals typically forgot about the presence of the wearable camera during use, remembering it only sporadically. One drawback to its use is that some participants were cautious of using the camera when around others, which impacted the amount of time the camera was worn, and, therefore, the nature of the data recorded. Design issues of the Sensecam were also a problem for the older adults in the study and affected their interaction with the technology
The use of a wearable camera to explore daily functioning of older adults living with persistent pain: Methodological reflections and recommendations
Background:
Persistent pain is prevalent within the ageing population and impacts daily functioning. Measuring daily functioning using conventional measures is problematic and novel technologies offer an alternative way of observing these behaviours.
Methods:
This study aimed to consider the use of a wearable camera as a method of exploring a range of day-to-day patterns of functioning of older adults living with persistent pain. This study followed a mixed methods design. A purposive sample of 13 older adults (65±) with persistent pain (pain >3 months) took part in this study. Two younger adults (<65) with persistent pain and two older adults with no pain also participated. Individuals used a wearable camera (Microsoft SenseCam) for seven days
Results:
The wearable camera recorded the frequency of body position, movement, and activities of daily living. The wearable camera also presented contextual data of location, social interactions, use of assistive devices, and behavioural adaptations and was used to inform other methods of data collection.
Conclusions:
The wearable camera allowed insight into patterns and experiences of daily functioning that would not have otherwise been captured. However, not all aspects of functioning were recorded using the wearable camera, including the relationship between functioning and persistent pain
Cadre conceptuel pour dĂ©finir la population statistique de lâĂ©conomie sociale au QuĂ©bec
Sous la direction de Marie J. BouchardLâobjectif du cadre conceptuel est de fournir des concepts et des dĂ©finitions pour guider la collecte
de donnĂ©es et la production de statistiques cohĂ©rentes et comparables sur lâĂ©conomie sociale
quĂ©bĂ©coise. Lâobjectif est aussi de contribuer au dĂ©veloppement de la recherche analytique sur
lâĂ©conomie sociale en identifiant des indicateurs pertinents pour la dĂ©crire quantitativement. Le
cadre conceptuel doit ĂȘtre Ă la fois assez gĂ©nĂ©ral pour tĂ©moigner de lâappartenance de lâĂ©conomie
sociale à un mouvement international, et assez particulier pour bien refléter son originalité
québécoise. Dans ce document, nous employons le terme économie sociale dans une définition large
et inclusive, couvrant les domaines de lâĂ©conomie sociale coopĂ©rative, mutualiste et sans but lucratif
ainsi que lâaction communautaire et lâaction communautaire autonome, tels que gĂ©nĂ©ralement
reconnus au Québec.
Le point de dĂ©part de la conceptualisation dâune dĂ©finition « statistique » de lâĂ©conomie sociale est la
DĂ©finition de lâĂ©conomie sociale adoptĂ©e au QuĂ©bec en 1996. Cette dĂ©finition, Ă lâinstar dâautres
dĂ©finitions employĂ©es ailleurs dans le monde, montre la primautĂ© de la finalitĂ© sociale sur lâactivitĂ©
économique. Ceci se manifeste notamment dans les traits empiriques qui sont caractéristiques des
structures et du fonctionnement de lâĂ©conomie sociale et qui la distinguent du reste de lâĂ©conomie.
Le cadre conceptuel qui en dĂ©coule Ă©tablit le type dâentitĂ©s, les statuts juridiques, les secteurs
dâactivitĂ©s exclus et un faisceau de critĂšres de qualification des organisations de lâĂ©conomie sociale.
Il Ă©tablit aussi une typologie des organisations. Le cadre conceptuel permet Ă©galement dâĂ©valuer les
composantes pĂ©riphĂ©riques du champ et de prĂ©voir sa propre Ă©volution (par ex. pour lâintĂ©gration
de nouvelles organisations qui seraient reconnues dâĂ©conomie sociale).
Les entitĂ©s de lâĂ©conomie sociale sont des entreprises (au sens de Statistique Canada) ayant les
statuts juridiques de coopĂ©ratives, mutuelles, ou dâorganismes sans but lucratif (OSBL). Le terme
« entreprise » nâĂ©tant pas utilisĂ© dans tous les milieux de lâĂ©conomie sociale, nous employons le
terme « organisations dâĂ©conomie sociale » de maniĂšre Ă toutes les englober.
Les secteurs du SystÚme de comptabilité nationale du Canada (SCNC) les plus susceptibles à contenir
des organisations dâĂ©conomie sociale sont le secteur des sociĂ©tĂ©s non financiĂšres, celui des sociĂ©tĂ©s
financiÚres et celui des institutions sans but lucratif au service des ménages. Il est peu probable de
trouver des organisations dâĂ©conomie sociale dans les autres secteurs Ă©conomiques du SCNC, Ă
savoir le secteur de lâadministration publique, celui des mĂ©nages, certaines parties du secteur des
institutions du secteur public au service des ménages et le secteur des entreprises non constituées
en sociĂ©tĂ©s. Certains secteurs dâactivitĂ© du SystĂšme de classification des industries de lâAmĂ©rique du Nord (SCIAN)
ne font pas partie de lâĂ©conomie sociale : les organismes religieux, les regroupements patronaux, les
regroupements professionnels, les syndicats et les partis politiques.
Des critĂšres permettent de qualifier les organisations qui font partie de lâĂ©conomie sociale (et leurs
filiales respectives) : la gouvernance démocratique; la distribution limitée ou interdite des
excĂ©dents ; lâautonomie et lâindĂ©pendance ; et la production organisĂ©e de biens ou de services. Un
seul de ces traits ne suffit pas pour caractĂ©riser lâĂ©conomie sociale, et ces traits ne sont pas
hiĂ©rarchisĂ©s entre eux. Câest plutĂŽt un ensemble de traits, ou un « faisceau de critĂšres », qui doit ĂȘtre
observĂ© pour qualifier lâĂ©conomie sociale. LâopĂ©rationnalisation de ces critĂšres se fait par tris
successifs, du plus simple au plus exigeant sur le plan méthodologique, de maniÚre à filtrer
progressivement la population statistique de lâĂ©conomie sociale. Au QuĂ©bec, les statuts juridiques de
la coopĂ©rative et de la mutuelle couvrent lâensemble des critĂšres du cadre conceptuel et permettent
dâemblĂ©e de classer ces organisations dans le champ. Les organisations ayant un statut juridique
dâorganisme sans but lucratif rencontrent le critĂšre de distribution limitĂ©e ou interdite des
excĂ©dents, mais doivent ĂȘtre examinĂ©es pour Ă©tablir (successivement, cette fois) quâils
correspondent aux critÚres de : a) production organisée de biens ou de services ; b) autonomie et
indépendance et c) gouvernance démocratique. Ainsi, puisque les organismes sans but lucratif
peuvent ĂȘtre mis sur pied pour de multiples fins, seuls ceux qui produisent de maniĂšre organisĂ©e
des biens ou des services font partie de lâĂ©conomie sociale. Ătant donnĂ© que les OSBL peuvent ĂȘtre
contrĂŽlĂ©s par des personnes ou des entitĂ©s qui nâen sont pas les membres, seuls ceux qui sont
exempts de contrĂŽle externe font partie de lâĂ©conomie sociale. Enfin, puisque OSBL nâont pas
dâobligation lĂ©gale en matiĂšre dâinspection, seuls ceux qui peuvent tĂ©moigner du fonctionnement de
leurs instances de gouvernance dĂ©mocratique font partie de lâĂ©conomie sociale.
Le cadre conceptuel sert aussi à développer une typologie qui vise à rendre compte de dynamiques
Ă©conomiques diffĂ©renciĂ©es des organisations dâĂ©conomie sociale. Se basant sur la capacitĂ©
dâhybridation des ressources qui caractĂ©rise lâĂ©conomie sociale, la typologie Ă©tablit six grands types
dâorganisations de lâĂ©conomie sociale suivant le mode dominant dâallocation des ressources
(échange marchand, redistribution ou réciprocité) et leur principale provenance (de source privée
ou publique). Cette typologie nâest certes pas suffisante pour classer les entitĂ©s de la population,
mais elle est complĂ©mentaire Ă dâautres classifications existantes1.
Lâadaptation du cadre conceptuel aux particularitĂ©s quĂ©bĂ©coises de lâĂ©conomie sociale permet de
tenir compte des entitĂ©s qui, aux vues du cadre conceptuel, paraissent ĂȘtre des « exceptions »
puisquâelles ne correspondent pas aux critĂšres du modĂšle logique, mais appartiennent nĂ©anmoins
au « mouvement » de lâĂ©conomie sociale du QuĂ©bec. Quelquesâuns de ces cas sont analysĂ©s en dĂ©tail
et sont intĂ©grĂ©s dans le ModĂšle logique opĂ©rationnel de lâĂ©conomie sociale au QuĂ©bec en 2011, qui
reprend les étapes du cadre général et tient compte des particularités québécoises.
Enfin, une analyse du cas des fondations permet de voir les caractéristiques de celles qui seraient le
plus susceptibles dâĂȘtre reconnues comme faisant partie de lâĂ©conomie sociale si la dĂ©finition
quĂ©bĂ©coise venait Ă les inclure. Ce type dâanalyse peut ĂȘtre repris pour dâautres organisations ou
secteurs dâactivitĂ©s, dans le contexte oĂč le cadre conceptuel viendrait Ă Ă©voluer.The objective of the conceptual framework is to supply concepts and definitions to guide the data
collection and the production of statistics which are coherent and comparable regarding QuĂ©becâs
social economy. The objective is also to contribute to the development of analytical research on
social economy by identifying relevant indicators to quantitatively describe it. The conceptual
framework must be quite general to establish the fact that the social economy is part of an
international movement and at the same time specific enough to properly reflect its Québec
originality. In this document, we will use the term âsocial economyâ in a large and inclusive
definition, which will cover the fields of cooperative, mutual and nonâprofit social economy, as well
as community action and autonomous community action as generally acknowledged in Québec.
The starting point of the conceptualization of the âstatisticalâ definition of social economy is the
Definition of Social Economy adopted in Québec in 1996. Like other definitions used elsewhere in the
world, this definition underlines the primacy of social purpose over economic activity. This is
especially shown in the empirical features which are typical of the structures and operation of the
social economy and which distinguish it from the rest of the economy. The resulting conceptual
framework establishes the type of entities, the legal status, sectors of activity which are excluded
and a cluster of qualification criteria of social economy organizations. It also establishes a typology
of organizations. The conceptual framework also allows assessing the peripheral components in this
field and forecasting its own progress (for example, for the integration of new organizations which
would be acknowledged as being part of the social economy).
Social economy entities are enterprises (within the meaning given by Statistics Canada) which have
legal status as cooperative, mutuals or nonâprofit organizations (NPOs). Because the term
âenterpriseâ is not used in all sectors of the social economy, we will use the term âsocial economy
organizationsâ so as to include all of them.
The sectors of the Canadian System of National Accounts (CSNA) which are the most likely to include
social economy organizations are those of nonâfinancial corporations, financial corporations and
nonâprofit institutions serving households. It is highly improbable that social economy
organizations will be found in other CSNA economic sectors, that is, the sectors of government,
households, some parts of the government institutions serving households sector and the
unincorporated business sector. Some sectors of activity of the North American Industry Classification System (NAICS) are not part of
the social economy. These are religious organizations, employersâ associations, professional
associations, trade unions and political parties.
Some criteria allow qualifying organizations which are part of the social economy (and their
respective subsidiaries): democratic governance; restricted or prohibited distribution of surplus;
autonomy and independence; and the organized production of goods or services. Only one criterion
is insufficient to characterize the social economy and there is no hierarchy of criteria. Instead, it is a
series of features or a âcluster of featuresâ which must be noted to qualify the social economy. The
operationalization of these criteria is done through successive triage from the simplest to the most
demanding from a methodological point of view, so as to progressively filter the statistical
population of the social economy. In Québec, the legal status of the cooperative and mutual cover all
of the criteria of the conceptual framework and allow classifying these organizations in this field.
Organizations that have legal status as nonâprofit organizations meet the criterion of limited or
prohibited distribution of surplus, but they must be examined to determine (successively this time)
if they correspond to the criteria of: a) organized production of goods or services; b) autonomy and
independence; and c) democratic governance. Accordingly, because nonâprofit organizations may be
established for many purposes, only those which produce goods or services in an organized manner
are part of the social economy. Considering that nonâprofit organizations may be controlled by
persons or entities which are not part of their membership, only those organizations which are not
externally controlled are part of the social economy. Finally, because nonâprofit organizations have
no legal requirement regarding inspection, only those which may attest to the operation of their
democratic processes of governance are part of the social economy.
The conceptual framework is also used to create a typology, the purpose of which is to account for
the differentiated economic dynamics of social economy organizations. Based on the capacity for
hybridization of the resources which characterizes the social economy, the typology establishes six
major types of organizations of the social economy according to the dominant mode of allocation of
resources (commercial exchange, redistribution or reciprocity) and their main source (private or
public). This typology is certainly insufficient to classify entities within the population but it is a
complement to other existing classifications2.
Adapting the conceptual framework to the specifics of QuĂ©becâs social economy allows taking into
consideration entities which seem to be âexceptionsâ as far as the conceptual framework is
concerned, because they do not correspond to the criteria of the logical model but nevertheless
belong to the social economy âmovementâ of QuĂ©bec. Some of these cases are analyzed in detail and
are integrated to the ModĂšle logique opĂ©rationnel de lâĂ©conomie sociale au QuĂ©bec en 2011 [Logical
Operational Model of the Social Economy in Québec in 2011], which repeats the steps of the general
framework and takes the specifics of Québec into consideration.
Finally, a case analysis of foundations shows the characteristics of those which would most likely be
acknowledged as being part of the social economy if the Québec definition would eventually include
them. If the conceptual framework should progress, this type of analysis may be repeated for other
organizations or sectors of activity.Le cadre conceptuel pour dĂ©finir la population statistique de lâĂ©conomie sociale au QuĂ©bec rĂ©sulte
dâune Ă©tude commandĂ©e par lâInstitut de la statistique du QuĂ©bec (ISQ), le ministĂšre de lâEmploi et
de la Solidarité sociale (MESS), le ministÚre de la Santé et des Services sociaux (MSSS) et le
SecrĂ©tariat Ă lâaction communautaire autonome et aux initiatives sociales (SACAIS). Le mandat a Ă©tĂ©
confiĂ© Ă la Chaire de recherche du Canada en Ă©conomie sociale de lâUQAM suite Ă un avis aux
chercheurs se clÎturant le 26 août 2010
A systematic review and meta-analysis of the reliability and validity of sensorimotor measurement instruments in people with chronic low back pain
Background: Deficits in the sensorimotor system and its peripheral and central processing of the affected body part might be a contributing factor to chronic low back pain (CLBP). Hence, sensorimotor assessment is important. Valid and reliable sensorimotor measurement instruments are needed. Objective: To investigate the reliability and validity of sensorimotor measurement instruments for people with chronic low back pain (CLBP). Design: Systematic review and meta-analysis. Methods: The review was undertaken using the COSMIN guidelines. Databases were searched for studies investigating the clinimetric properties of sensorimotor tests in people with CLBP. The methodological study quality was rated by two independent reviewers using the COSMIN 4-point rating checklist. Results: Ten studies were included covering six sensorimotor measurement instruments with findings for reliability/measurement error, known-groups validity and convergent validity. The methodological quality ranged from poor to good, with only one study rated as good. There was insufficient evidence of enough quality to assess reliability/measurement error or convergent validity. Two-point discrimination, laterality judgement and movement control tests had moderate evidence supporting their ability to distinguish between healthy people and those with CLBP. Conclusions: Two-point discrimination, laterality judgment and movement control tests demonstrate the greatest level of known-groups validity for people with CLBP. However, as the reliability of these measurement tools has yet to be established, this validity data should be interpreted cautiously. Further research is warranted to investigate the clinimetric properties of these sensorimotor techniques.</p
Spin noise and Bell inequalities in a realistic superconductor-quantum dot entangler
Charge and spin current correlations are analyzed in a source of
spin-entangled electrons built from a superconductor and two quantum dots in
parallel. In addition to the ideal (crossed Andreev) channel, parasitic
channels (direct Andreev and cotunneling) and spin flip processes are fully
described in a density matrix framework. The way they reduce both the
efficiency and the fidelity of the entangler is quantitatively described by
analyzing the zero-frequency noise correlations of charge current as well as
spin current in the two output branches. Spin current noise is characterized by
a spin Fano factor, equal to 0 (total current noise) and -1 (crossed
correlations) for an ideal entangler. The violation of the Bell inequalities,
as a test of non-locality (entanglement) of split pairs, is formulated in terms
of the correlations of electron charge and spin numbers counted in a specific
time window . The efficiency of the test is analyzed, comparing to
the various time scales in the entangler operation.Comment: 8 pages, 5 figures, references added, to appear in Phys. Rev.
NASA Space applications of high-temperature superconductors
The application of superconducting technology in space has been limited by the requirement of cooling to near liquid helium temperatures. The only means of obtaining these temperatures has been with cryogenic fluids which severely limit mission lifetime. The development of materials with superconducting transition temperatures above 77 K has made superconducting technology more attractive and feasible for employment in aerospace systems. Here, potential applications of high temperature superconducting technology in cryocoolers, remote sensing, communications, and power systems are discussed
A comparison between quantum chemistry and quantum Monte Carlo techniques for the adsorption of water on the (001) LiH surface
We present a comprehensive benchmark study of the adsorption energy of a
single water molecule on the (001) LiH surface using periodic coupled cluster
and quantum Monte Carlo theories. We benchmark and compare different
implementations of quantum chemical wave function based theories in order to
verify the reliability of the predicted adsorption energies and the employed
approximations. Furthermore we compare the predicted adsorption energies to
those obtained employing widely-used van der Waals density-functionals. Our
findings show that quantum chemical approaches are becoming a robust and
reliable tool for condensed phase electronic structure calculations, providing
an additional tool that can also help in potentially improving currently
available van der Waals density-functionals
Theory of the ac spin-valve effect
The spin-valve complex magnetoimpedance of symmetric ferromagnet/normal
metal/ferromagnet junctions is investigated within the drift-diffusion
(standard) model of spin injection. The ac magnetoresistance---the real part
difference of the impedances of the parallel and antiparallel magnetization
configurations---exhibits an overall damped oscillatory behavior, as an
interplay of the diffusion and spin relaxation times. In wide junctions the ac
magnetoresistance oscillates between positive and negative values, reflecting
resonant amplification and depletion of the spin accumulation, while the line
shape for thin tunnel junctions is predicted to be purely Lorentzian. The ac
spin-valve effect could be a technique to extract spin transport and spin
relaxation parameters in the absence of a magnetic field and for a fixed sample
size.Comment: 5 pages, 4 figure
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