2,864 research outputs found

    Specifying Multimedia Binding Objects in Z

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    The current standardisation activity of Open Distributed Processing (ODP) has attempted to incorporate multimedia flows of information into its architecture through the idea of stream interfaces. At present the reference model of ODP (ODP-RM) abstracts from the precise nature of the flows of information. As a consequence of this, the ODPRM only deals with syntactic aspects of stream interfaces and does not require them to satisfy any behavioural considerations. It is shown in this paper how the formal notation Z can be used to reason about these flows of information in a manner that enables behavioural as well as temporal aspects to be considered. The example given to highlight the approach is the ODP concept of a binding object

    Standardisation of magnetic nanoparticles in liquid suspension

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    Suspensions of magnetic nanoparticles offer diverse opportunities for technology innovation, spanning a large number of industry sectors from imaging and actuation based applications in biomedicine and biotechnology, through large-scale environmental remediation uses such as water purification, to engineering-based applications such as position-controlled lubricants and soaps. Continuous advances in their manufacture have produced an ever-growing range of products, each with their own unique properties. At the same time, the characterisation of magnetic nanoparticles is often complex, and expert knowledge is needed to correctly interpret the measurement data. In many cases, the stringent requirements of the end-user technologies dictate that magnetic nanoparticle products should be clearly defined, well characterised, consistent and safe; or to put it another way—standardised. The aims of this document are to outline the concepts and terminology necessary for discussion of magnetic nanoparticles, to examine the current state-of-the-art in characterisation methods necessary for the most prominent applications of magnetic nanoparticle suspensions, to suggest a possible structure for the future development of standardisation within the field, and to identify areas and topics which deserve to be the focus of future work items. We discuss potential roadmaps for the future standardisation of this developing industry, and the likely challenges to be encountered along the way

    Transport Coefficients of Gluon Plasma

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    Transport coefficients of gluon plasma are calculated for a SU(3) pure gauge model by lattice QCD simulations on 163×816^3 \times 8 and 243×824^3 \times 8 lattices. Simulations are carried out at a slightly above the deconfinement transition temperature TcT_c, where a new state of matter is currently being pursued in RHIC experiments. Our results show that the ratio of the shear viscosity to the entropy is less than one and the bulk viscosity is consistent with zero in the region, 1.4T/Tc1.81.4 \leq T/T_c \leq 1.8 .Comment: 10 pages, Late

    Equivalence of Several Chern-Simons Matter Models

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    Not only does Chern-Simons (CS) coupling characterize statistics, but also spin and scaling dimension of matter fields. We demonstrate spin transmutation in relativistic CS matter theory, and moreover show equivalence of several models. We study CS vector model in some details, which provide consistent check to the assertion of the equivalence.Comment: latex, 7page, IFT-478-UNC/NUP-A-93-15 A version within the length limit for Phys. Rev. Letts (in press

    Note on Gauge Theory on Fuzzy Supersphere

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    We construct a supermatrix model whose classical background gives two-dimensional noncommutative supersphere. Quantum fluctuations around it give the supersymmetric gauge theories on the fuzzy supersphere constructed by Klimcik. This model has a parameter β\beta which can tune masses of the particles in the model and interpolate various supersymmetric gauge theories on sphere.Comment: 13 pages, LaTe

    Smooth Paths on Three Dimensional Lattice

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    A particular class of random walks with a spin factor on a three dimensional cubic lattice is studied. This three dimensional random walk model is a simple generalization of random walk for the two dimensional Ising model. All critical diffusion constants and associated critical exponents are calculated. Continuum field theories such as Klein-Gordon, Dirac and massive Chern-Simons theories are constructed near several critical points.Comment: 7 pages,NUP-A-94-

    Scaling Behaviors of Branched Polymers

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    We study the thermodynamic behavior of branched polymers. We first study random walks in order to clarify the thermodynamic relation between the canonical ensemble and the grand canonical ensemble. We then show that correlation functions for branched polymers are given by those for ϕ3\phi^3 theory with a single mass insertion, not those for the ϕ3\phi^3 theory themselves. In particular, the two-point function behaves as 1/p41/p^4, not as 1/p21/p^2, in the scaling region. This behavior is consistent with the fact that the Hausdorff dimension of the branched polymer is four.Comment: 17 pages, 3 figure

    Ginsparg-Wilson Relation, Topological Invariants and Finite Noncommutative Geometry

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    We show that the Ginsparg-Wilson (GW) relation can play an important role to define chiral structures in {\it finite} noncommutative geometries. Employing GW relation, we can prove the index theorem and construct topological invariants even if the system has only finite degrees of freedom. As an example, we consider a gauge theory on a fuzzy two-sphere and give an explicit construction of a noncommutative analog of the GW relation, chirality operator and the index theorem. The topological invariant is shown to coincide with the 1st Chern class in the commutative limit.Comment: Revtex4 file, 5 pages, references added, typo corrected, the final version to appear in Phys.Rev.

    Noise control by sonic crystal barriers made of recycled materials

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    A systematic study of noise barriers based on sonic crystals made of cylinders that use recycled materials like absorbing component is here reported. The barriers consist of only three rows of perforated metal shells filled with rubber crumb. Measurements of reflectance and transmittance by these barriers are reported. Their attenuation properties result from a combination of sound absorption by the rubber crumb and reflection by the periodic distribution of scatterers. It is concluded that porous cylinders can be used as building blocks whose physical parameters can be optimized in order to design efficient barriers adapted to different noisy environments

    Gauge Theory on Noncommutative Supersphere from Supermatrix Model

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    We construct a supermatrix model which has a classical solution representing the noncommutative (fuzzy) two-supersphere. Expanding supermatrices around the classical background, we obtain a gauge theory on a noncommutative superspace on sphere. This theory has osp(12)osp(1|2) supersymmetry and u(2L+12L)u(2L+1|2L) gauge symmetry. We also discuss a commutative limit of the model keeping radius of the supersphere fixed.Comment: 16 pages, Latex, typos corrected, references adde
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