1,364 research outputs found

    A hierarchy of compatibility and comeasurability levels in quantum logics with unique conditional probabilities

    Full text link
    In the quantum mechanical Hilbert space formalism, the probabilistic interpretation is a later ad-hoc add-on, more or less enforced by the experimental evidence, but not motivated by the mathematical model itself. A model involving a clear probabilistic interpretation from the very beginning is provided by the quantum logics with unique conditional probabilities. It includes the projection lattices in von Neumann algebras and here probability conditionalization becomes identical with the state transition of the Lueders - von Neumann measurement process. This motivates the definition of a hierarchy of five compatibility and comeasurability levels in the abstract setting of the quantum logics with unique conditional probabilities. Their meanings are: the absence of quantum interference or influence, the existence of a joint distribution, simultaneous measurability, and the independence of the final state after two successive measurements from the sequential order of these two measurements. A further level means that two elements of the quantum logic (events) belong to the same Boolean subalgebra. In the general case, the five compatibility and comeasurability levels appear to differ, but they all coincide in the common Hilbert space formalism of quantum mechanics, in von Neumann algebras, and in some other cases.Comment: 12 page

    Automatisering i norske kommuner : status og veien videre

    Get PDF
    Masteroppgave informasjonssystemer IS501 - Universitetet i Agder 2018Bakgrunnen for studien er å kartlegge hvor utbredt automatisering er i norske kommuner, og finne faktorer som påvirker automatiseringen. Denne eksplorative studien kombinerer ulike metoder som litteraturgjennomganger, intervjuer og spørreundersøkelse, for å belyse en problemstilling i et felt med lite tidligere forskning: «Hvor utbredt er automatisering i norske kommuner, og hvilke faktorer påvirker automatiseringen?» Etter en grundig litteraturgjennomgang, gjennomførte vi totalt 8 semistrukturerte intervjuer med 12 respondenter. Respondentene fortalte om prosjekter og fremtidige planer for automatisering, samt oppfatninger om hva som kan være påvirkningsfaktorer. Innspill og faktorer er videre tatt med til spørreundersøkelsen. Spørreundersøkelsen gir innsikt i norske kommuners status for automatisering, og hvilke faktorer som påvirker automatiseringen. Spørreundersøkelsen viser deltakelse fra kommuner i alle norske fylker, som resulterte med 105 deltakere (25%). Videre gjennomførte 71 kommuner hele undersøkelsen. Studien viser at automatisering er ettertraktet i norske kommuner. Det jobbes med i dag, og er høyt prioritert fremover. Kommuner er i gang med digitaliseringsprosessen, som har stor innvirkning på automatiseringen. Store kommuner stiller ofte sterkere med ressurser enn de mindre, som også viser at de ligger lengre fremme i utviklingen. Store kommuner benytter også oftere robotiserte løsninger, RPA. Vi konkluderer med at mange kommuner er i gang med automatisering, men at det er forskjeller i omfanget. Studien identifiserer 17 faktorer som påvirker automatiseringen, innenfor fire områder: teknologiske, prosessrelaterte og organisatoriske faktorer, samt offentlige føringer. Norske kommuner viser til mye bruk av gamle IT-systemer. Videre gir det utfordringer for integreringen av nyere systemer, fellesløsninger og nasjonale komponenter. Ved å stille sterkt i prosessorientering, er det enklere for kommuner å identifisere automatiseringsmuligheter. Prosesser bør kartlegges bedre og prosesseiere etableres. Videre viser studien at en digital transformasjon er krevende for kommuner. Ny digital teknologi endrer prosesser, og fører til nye måter å levere tjenester på. Samarbeid og deling av erfaring mellom kommuner og stat fremmer en effektiv utvikling i automatiseringen, og legger opp til standardisering med fellesløsninger. Kompetanseutvikling er et behov når arbeidsprosesser automatiseres, slik at ansatte er trygge på endringene og ønsker automatiserte løsninger. Regjeringen stiller med krav og anbefalinger for kommuners automatisering, og kommuner anbefales derfor å jobbe målrettet med politisk forankring som styrer arbeidet mot automatiseringen. Det er flere veier til automatisering. Faktorene gir nyttig informasjon om mulige veivalg til automatisering som kommuner kan tilpasse egne strategier og forutsetninger. De teknologiske og organisatoriske faktorene hjelper kommunene mot bedre standardisert infrastruktur og overgang til automatisering. Offentlige føringer tilrettelegger for styring av automatiseringsmulighetene, noe som også gjøres enklere for kommuner ved å bli mer prosessorientert. Vår studie bidrar til videre forskning på utbredelse og innføring av automatisering i norske kommuner, og dens identifiserte påvirkningsfaktorer. Staten er sentral for fellesløsninger og krav for digitalisering og automatisering i norske kommuner. Våre funn viser behov for videre forskning som utdyper hvordan implementering kan gjøres mer effektiv og hva som bør prioriteres. Det bør også forskes på hvordan kommuner kan bli mer prosessorientert for å finne automatiseringsmuligheter, leverandørenes rolle og hvilken innvirkning GDPR har for automatisering videre

    Negative c-axis magnetoresistance in graphite

    Full text link
    We have studied the c-axis interlayer magnetoresistance (ILMR), R_c(B) in graphite. The measurements have been performed on strongly anisotropic highly oriented pyrolytic graphite (HOPG) samples in magnetic field up to B = 9 T applied both parallel and perpendicular to the sample c-axis in the temperature interval 2 K < T < 300 K. We have observed negative magnetoresistance, dR_c/dB < 0, for B || c-axis above a certain field B_m(T) that reaches its minimum value B_m = 5.4 T at T = 150 K. The results can be consistently understood assuming that ILMR is related to a tunneling between zero-energy Landau levels of quasi-two-dimensional Dirac fermions, in a close analogy with the behavior reported for alpha-(BEDT-TTF)2I3 [N. Tajima et al., Phys. Rev. Lett. 102, 176403 (2009)], another multilayer Dirac electron system.Comment: 14 pages, including 4 figure

    Hospital managers' need for information in decision-making--An interview study in nine European countries.

    Get PDF
    Assessments of new health technologies in Europe are often made at the hospital level. However, the guidelines for health technology assessment (HTA), e.g. the EUnetHTA Core Model, are produced by national HTA organizations and focus on decision-making at the national level. This paper describes the results of an interview study with European hospital managers about their need for information when deciding about investments in new treatments. The study is part of the AdHopHTA project. Face-to-face, structured interviews were conducted with 53 hospital managers from nine European countries. The hospital managers identified the clinical, economic, safety and organizational aspects of new treatments as being the most relevant for decision-making. With regard to economic aspects, the hospital managers typically had a narrower focus on budget impact and reimbursement. In addition to the information included in traditional HTAs, hospital managers sometimes needed information on the political and strategic aspects of new treatments, in particular the relationship between the treatment and the strategic goals of the hospital. If further studies are able to verify our results, guidelines for hospital-based HTA should be altered to reflect the information needs of hospital managers when deciding about investments in new treatments

    Fish Spawning Aggregations: Where Well-Placed Management Actions Can Yield Big Benefits for Fisheries and Conservation

    Get PDF
    Marine ecosystem management has traditionally been divided between fisheries management and biodiversity conservation approaches, and the merging of these disparate agendas has proven difficult. Here, we offer a pathway that can unite fishers, scientists, resource managers and conservationists towards a single vision for some areas of the ocean where small investments in management can offer disproportionately large benefits to fisheries and biodiversity conservation. Specifically, we provide a series of evidenced-based arguments that support an urgent need to recognize fish spawning aggregations (FSAs) as a focal point for fisheries management and conservation on a global scale, with a particular emphasis placed on the protection of multispecies FSA sites. We illustrate that these sites serve as productivity hotspots - small areas of the ocean that are dictated by the interactions between physical forces and geomorphology, attract multiple species to reproduce in large numbers and support food web dynamics, ecosystem health and robust fisheries. FSAs are comparable in vulnerability, importance and magnificence to breeding aggregations of seabirds, sea turtles and whales yet they receive insufficient attention and are declining worldwide. Numerous case-studies confirm that protected aggregations do recover to benefit fisheries through increases in fish biomass, catch rates and larval recruitment at fished sites. The small size and spatio-temporal predictability of FSAs allow monitoring, assessment and enforcement to be scaled down while benefits of protection scale up to entire populations. Fishers intuitively understand the linkages between protecting FSAs and healthy fisheries and thus tend to support their protection

    Regulation of murine airway surface liquid volume by CFTR and Ca2+-activated Cl- conductances

    Get PDF
    Two Cl- conductances have been described in the apical membrane of both human and murine proximal airway epithelia that are thought to play predominant roles in airway hydration: (1) CFTR, which is cAMP regulated and (2) the Ca2+-activated Cl- conductance (CaCC) whose molecular identity is uncertain. In addition to second messenger regulation, cross talk between these two channels may also exist and, whereas CFTR is absent or defective in cystic fibrosis (CF) airways, CaCC is preserved, and may even be up-regulated. Increased CaCC activity in CF airways is controversial. Hence, we have investigated the effects of CFTR on CaCC activity and have also assessed the relative contributions of these two conductances to airway surface liquid (ASL) height (volume) in murine tracheal epithelia. We find that CaCC is up-regulated in intact murine CF tracheal epithelia, which leads to an increase in UTP-mediated Cl-/volume secretion. This up-regulation is dependent on cell polarity and is lost in nonpolarized epithelia. We find no role for an increased electrical driving force in CaCC up-regulation but do find an increased Ca2+ signal in response to mucosal nucleotides that may contribute to the increased Cl-/volume secretion seen in intact epithelia. CFTR plays a critical role in maintaining ASL height under basal conditions and accordingly, ASL height is reduced in CF epithelia. In contrast, CaCC does not appear to significantly affect basal ASL height, but does appear to be important in regulating ASL height in response to released agonists (e.g., mucosal nucleotides). We conclude that both CaCC and the Ca2+ signal are increased in CF airway epithelia, and that they contribute to acute but not basal regulation of ASL height

    First-principles extrapolation method for accurate CO adsorption energies on metal surfaces

    Full text link
    We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by DFT and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO 2π\pi* orbital found recently {[Kresse {\em et al.}, Physical Review B {\bf 68}, 073401 (2003)]}. Converged DFT calculations underestimate the CO singlet-triplet excitation energy ΔEST\Delta E_{\rm S-T}, whereas coupled-cluster and CI calculations reproduce the experimental ΔEST\Delta E_{\rm S-T}. The dependence of EchemE_{\rm chem} on ΔEST\Delta E_{\rm S-T} is used to extrapolate EchemE_{\rm chem} for the top, bridge and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd and Cu to the values that correspond to the coupled-cluster and CI ΔEST\Delta E_{\rm S-T} value. The correction reproduces experimental adsorption site preference for all cases and obtains EchemE_{\rm chem} in excellent agreement with experimental results.Comment: Table sent as table1.eps. 3 figure

    Atom-optics hologram in the time domain

    Full text link
    The temporal evolution of an atomic wave packet interacting with object and reference electromagnetic waves is investigated beyond the weak perturbation of the initial state. It is shown that the diffraction of an ultracold atomic beam by the inhomogeneous laser field can be interpreted as if the beam passes through a three-dimensional hologram, whose thickness is proportional to the interaction time. It is found that the diffraction efficiency of such a hologram may reach 100% and is determined by the duration of laser pulses. On this basis a method for reconstruction of the object image with matter waves is offered.Comment: RevTeX, 13 pages, 8 figures; minor grammatical change
    corecore