1,035 research outputs found

    Testing Identifiable Kernel P Systems Using an X-machine Approach

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    This paper presents a testing approach for kernel P systems (kP systems), based on the X-machine testing framework and the concept of cover automaton. The testing methodology ensures that the implementation conforms the speci cations, under certain conditions, such as the identi ably concept in the context of kernel P systems

    Magneto-optical imaging of magnetic deflagration in Mn12-Acetate

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    For the first time, the morphology and dynamics of spin avalanches in Mn12-Acetate crystals using magneto-optical imaging has been explored. We observe an inhomogeneous relaxation of the magnetization, the spins reversing first at one edge of the crystal and a few milliseconds later at the other end. Our data fit well with the theory of magnetic deflagration, demonstrating that very slow deflagration rates can be obtained, which makes new types of experiments possible.Comment: 5 two-column pages, 3 figures, EPL styl

    Opportunities and challenges for implementing cost accounting systems in the Kenyan health system.

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    Low- and middle-income countries need to sustain efficiency and equity in health financing on their way to universal health care coverage. However, systems meant to generate quality economic information are often deficient in such settings. We assessed the feasibility of streamlining cost accounting systems within the Kenyan health sector to illustrate the pragmatic challenges and opportunities. We reviewed policy documents, and conducted field observations and semi-structured interviews with key informants in the health sector. We used an adapted Human, Organization and Technology fit (HOT-fit) framework to analyze the components and standards of a cost accounting system. Among the opportunities for a viable cost accounting system, we identified a supportive broad policy environment, political will, presence of a national data reporting architecture, good implementation experience with electronic medical records systems, and the availability of patient clinical and resource use data. However, several practical issues need to be considered in the design of the system, including the lack of a framework to guide the costing process, the lack of long-term investment, the lack of appropriate incentives for ground-level staff, and a risk of overburdening the current health management information system. To facilitate the implementation of cost accounting into the health sector, the design of any proposed system needs to remain simple and attuned to the local context

    On essential self-adjointness for magnetic Schroedinger and Pauli operators on the unit disc in R^2

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    We study the question of magnetic confinement of quantum particles on the unit disk \ID in \IR^2, i.e. we wish to achieve confinement solely by means of the growth of the magnetic field B(x)B(\vec x) near the boundary of the disk. In the spinless case we show that B(x)321(1r)2131(1r)2ln11rB(\vec x)\ge \frac{\sqrt 3}{2}\cdot\frac{1}{(1-r)^2}-\frac{1}{\sqrt 3}\frac{1}{(1-r)^2\ln \frac{1}{1-r}}, for x|\vec x| close to 1, insures the confinement provided we assume that the non-radially symmetric part of the magnetic field is not very singular near the boundary. Both constants 32\frac{\sqrt 3}{2} and 13-\frac{1}{\sqrt 3} are optimal. This answers, in this context, an open question from Y. Colin de Verdi\`ere and F. Truc. We also derive growth conditions for radially symmetric magnetic fields which lead to confinement of spin 1/2 particles.Comment: 18 pages; the main theorem has been expanded and generalize

    Modelling and validating an engineering application in kernel P systems

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    © 2018, Springer International Publishing AG. This paper illustrates how kernel P systems (kP systems) can be used for modelling and validating an engineering application, in this case a cruise control system of an electric bike. The validity of the system is demonstrated via formal verification, carried out using the kPWorkbench tool. Furthermore, we show how the kernel P system model can be tested using automata and X-machine based techniques

    Correlation-temperature phase diagram of prototypical infinite layer rare earth nickelates

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    The discovery of superconductivity in hole-doped infinite layer nickelates, RNiO2 (R = Nd, Pr, La) has garnered sustained interest in the field. A definitive picture of low-energy many-body states has not yet emerged. We provide new insights into the low-energy physics, based on our embedded dynamical mean-field theory calculations, and propose a correlation (U)-temperature (T) phase diagram. The key features are a low-T Fermi liquid (FL) phase, a high-T Curie-Weiss regime, and an antiferromagnetic phase in a narrow U-T region. We associate the onset of the FL phase with partial screening of Ni-d moments; however, full screening occurs at lower temperatures. This may be related to insufficiency of conduction electrons to effectively screen the Ni-d moments, suggestive of Nozieres Exhaustion Principle. Our results suggest that RNiO2 are in the paramagnetic state, close to an antiferromagnetic dome, making magnetic fluctuations feasible. This may be consequential for superconductivity.Comment: 19 pages, 18 figure

    Imaging of hemoglobin oxygen saturation variations in single vessels in vivo using photoacoustic microscopy

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    Photoacoustic microscopy was used to noninvasively image variations in hemoglobin oxygen saturation (SO_2) in the subcutaneous microvasculature of rats in vivo. In phantom tests, the calculated concentration fractions of red ink in double-ink mixtures matched the actual values with a 1% error. In ex vivo studies, the calculated SO_2 in bovine blood agreed with the standard spectrophotometric measurements within a 4% systematic difference. In in vivo studies, arteries and veins were separated based on the measured SO_2 values and variations in SO_2 between different physiological states (hyperoxia, normoxia, and hypoxia) were imaged in single blood vessels
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