9,790 research outputs found
Implementing Session Centered Calculi
Recently, specific attention has been devoted to the development of service oriented process calculi. Besides the foundational aspects, it is also interesting to have prototype implementations for them in order to assess usability and to minimize the gap between theory and practice. Typically, these implementations are done in Java taking advantage of its mechanisms supporting network applications. However, most of the recurrent features of service oriented applications are re-implemented from scratch. In this paper we show how to implement a service oriented calculus, CaSPiS (Calculus of Services with Pipelines and Sessions) using the Java framework IMC, where recurrent mechanisms for network applications are already provided. By using the session oriented and pattern matching communication mechanisms provided by IMC, it is relatively simple to implement in Java all CaSPiS abstractions and thus to easily write the implementation in Java of a CaSPiS process
Large-N reduction for N=2 quiver Chern-Simons theories on S^3 and localization in matrix models
We study reduced matrix models obtained by the dimensional reduction of N=2
quiver Chern-Simons theories on S^3 to zero dimension and show that if a
reduced model is expanded around a particular multiple fuzzy sphere background,
it becomes equivalent to the original theory on S^3 in the large-N limit. This
is regarded as a novel large-N reduction on a curved space S^3. We perform the
localization method to the reduced model and compute the free energy and the
vacuum expectation value of a BPS Wilson loop operator. In the large-N limit,
we find an exact agreement between these results and those in the original
theory on S^3.Comment: 46 pages, 11 figures; minor modification
Bending and springback prediction method based on multi-scale finite element analyses for high bendability and low springback sheet generation
In this study, a sheet bendability and springback property evaluation technology through bending test simulations is newly developed using our multi-scale finite element analysis code, which is based on the crystallographic homogenization method
Transitive X-ray spectrum and PeV gamma-ray cutoff in the M87 jet: Electron "Pevatron"
We propose a modified version of the X-ray spectral index and an intrinsic
cutoff frequency of inverse Compton radiation from the brightest knot of the
M87 jet, in conjunction with an application of the new conceptions of injection
and diffusive shock acceleration (DSA) of electrons in magnetized filamentary
plasma to the specified source. The drop of the X-ray flux density in a
transitive frequency region is associated with the interplay of ordinary
synchrotron cooling and weaker magnetic fields concomitant with the smaller
scale filaments that allow the electron injection, while the radio-optical
synchrotron continuum is dominantly established by the major electrons that are
quasi-secularly bound to larger filaments. With reference to, particularly, the
updated external Compton model, we demonstrate that in the Klein-Nishina regime
fading inverse Comptonization, the injected electrons can be stochastically
energized up to a Lorentz factor as high as in the temporal
competition with diffuse synchrotron cooling; this value is larger than that
attainable for a simple DSA scenario based on the resonant scattering diffusion
of the gyrating electrons bound to a supposed magnetic field homogeneously
pervading the entire knot. The upper limits of the photon frequency boosted via
conceivable inverse Compton processes are predicted to be of the common order
of Hz. The variability of the broadband spectrum is also
discussed in comparison to the features of a blazar light curve. The present
scenario of a peta-eV (PeV; eV) electron accelerator, the "Pevatron,"
might provide some guidance for exploring untrod hard X-ray and gamma-ray bands
in forthcoming observations.Comment: 34 pages, 6 figures, matches version published in Ap
Right-veering diffeomorphisms of compact surfaces with boundary II
We continue our study of the monoid of right-veering diffeomorphisms on a
compact oriented surface with nonempty boundary, introduced in [HKM2]. We
conduct a detailed study of the case when the surface is a punctured torus; in
particular, we exhibit the difference between the monoid of right-veering
diffeomorphisms and the monoid of products of positive Dehn twists, with the
help of the Rademacher function. We then generalize to the braid group B_n on n
strands by relating the signature and the Maslov index. Finally, we discuss the
symplectic fillability in the pseudo-Anosov case by comparing with the work of
Roberts [Ro1,Ro2].Comment: 25 pages, 5 figure
Electronic transport properties of quasicrystals: a Review
We present a review of some results concerning electronic transport
properties of quasicrystals. After a short introduction to the basic concepts
of quasiperiodicity, we consider the experimental transport properties of
electrical conductivity with particular focus on the effect of temperature,
magnetic field and defects. Then, we present some heuristic approaches that
tend to give a coherent view of different, and to some extent complementary,
transport mechanisms in quasicrystals. Numerical results are also presented and
in particular the evaluation of the linear response Kubo-Greenwood formula of
conductivity in quasiperiodic systems in presence of disorder.Comment: Latex, 28 pages, Journ. of Math. Phys., Vol38 April 199
Noble gases in diamonds: Occurrences of solarlike helium and neon
We have measured noble gases in 17 diamond samples, mostly inclusion free, from diverse, known locations. The ^3He/^4He ratios are characterized by a large spread (10^4), ranging from values below atmospheric to close to the solar ratio. Highest ratios were seen for an Australian colorless diamond composite and an Arkansas diamond. These samples also have imprecise but intriguing neon isotopic ratios, which are close to the solar value. An origin for the solarlike He and Ne in the diamond samples is unlikely to be accounted for by the presence of nucleogenic or spallogenic components. For single diamond stones a positive correlation is found between ^3He/^4He and ^(13)C/^(12)C, possibly indicating that heavy carbon is accompanied by primordial helium. However, the He result for the Australian colorless diamond composite with low δ^(13)C value requires another explanation, possibly sedimentary carbon contaminated with cosmic dust. The wide variation in ^4He/^(40)_*Ar ratios observed from diamond samples suggests a complex history for the source regions and the diamond crystallization processes. Results for two Australian diamond composites (colorless and colored), which came from the same kimberlite pipe, are especially notable: the colorless stones contain no radiogenic components but solarlike He and Ne isotopic ratios, whereas the colored stones are enriched in radiogenic and fissiogenic components. Seemingly the Australian diamonds crystallized in a heterogeneous environment in the mantle source region. A pair of Arkansas diamonds, believed to be from a single pipe, exhibits similar anomalies
Half-ordered state in the anisotropic Haldane-gap antiferromagnet NDMAP
Neutron diffraction experiments performed on the Haldane gap material NDMAP
in high magnetic fields applied at an angle to the principal anisotropy axes
reveal two consecutive field-induced phase transitions. The low-field phase is
the gapped Haldane state, while at high fields the system exhibits
3-dimensional long-range Neel order. In a peculiar phase found at intermediate
fields only half of all the spin chains participate in the long-range ordering,
while the other half remains disordered and gapped.Comment: 4 pages, 2 figures, submitted to Phys. Rev.
Multi-physics Extension of OpenFMO Framework
OpenFMO framework, an open-source software (OSS) platform for Fragment
Molecular Orbital (FMO) method, is extended to multi-physics simulations (MPS).
After reviewing the several FMO implementations on distributed computer
environments, the subsequent development planning corresponding to MPS is
presented. It is discussed which should be selected as a scientific software,
lightweight and reconfigurable form or large and self-contained form.Comment: 4 pages with 11 figure files, to appear in the Proceedings of ICCMSE
200
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