311 research outputs found
Wodzicki Residue for Operators on Manifolds with Cylindrical Ends
We define the Wodzicki Residue TR(A) for A in a space of operators with
double order (m_1,m_2). Such operators are globally defined initially on R^n
and then, more generally, on a class of non-compact manifolds, namely, the
manifolds with cylindrical ends. The definition is based on the analysis of the
associate zeta function. Using this approach, under suitable ellipticity
assumptions, we also compute a two terms leading part of the Weyl formula for a
positive selfadjoint operator belonging the mentioned class in the case
m_1=m_2.Comment: 24 pages, picture changed, added references, corrected typo
Sound Multi-Party Business Protocols for Service Networks
Service networks comprise large numbers of long-running, highly dynamic complex end-to-end service interactions reflecting asynchronous message flows that typically transcend several organizations and span several geographical locations. At the communication level, service network business protocols can be flexible ranging from conventional inter-organizational point-to-point service interactions to fully blown dynamic multi-party interactions of global reach within which each participant may contribute its activities and services. In this paper we introduce a formal framework enriched with temporal constraints to describe multiparty business protocols for service networks. We extend this framework with the notion of multi-party business protocol soundness and show how it is possible to execute a multi-party protocol consistently in a completely distributed manner while guaranteeing eventual termination
The determination of the electron-phonon interaction from tunneling data in the two-band superconductor MgB2
We calculate the tunneling density of states (DOS) of MgB2 for different
tunneling directions, by directly solving the real-axis, two-band Eliashberg
equations (EE). Then we show that the numeric inversion of the standard
single-band EE, if applied to the DOS of the two-band superconductor MgB2, may
lead to wrong estimates of the strength of certain phonon branches (e.g. the
E_2g) in the extracted electron-phonon spectral function alpha^(2)F(omega). The
fine structures produced by the two-band interaction turn out to be clearly
observable only for tunneling along the ab planes in high-quality single
crystals. The results are compared to recent experimental data.Comment: 2 pages, 2 figures, proceedings of M2S-HTSC-VII conference, Rio de
Janeiro (May 2003
Fast algorithms for handling diagonal constraints in timed automata
A popular method for solving reachability in timed automata proceeds by
enumerating reachable sets of valuations represented as zones. A na\"ive
enumeration of zones does not terminate. Various termination mechanisms have
been studied over the years. Coming up with efficient termination mechanisms
has been remarkably more challenging when the automaton has diagonal
constraints in guards.
In this paper, we propose a new termination mechanism for timed automata with
diagonal constraints based on a new simulation relation between zones.
Experiments with an implementation of this simulation show significant gains
over existing methods.Comment: Shorter version of this article to appear in CAV 201
TerrHum: an iPhone app for classifying forest humipedons.
The knowledge of a little number of specific terms is necessary to investigate and describe the forest topsoils: diagnostic components, diagnostic organic and organic-mineral horizons and the 17 series of humus horizons composing all the observed real forest not submerged topsoils. Diagnostic horizons are grouped in humus forms, which represent five humus systems. To become a good topsoil investigator is then only a question of field experience. No mean to do otherwise: you must go in the field with a blade and a good manual and put your hand in the soil. You have to make a hole and to observe on your knee a wall of the pit, from the top to the bottom, detecting all the characters that you find indicated in the manual. At the beginning you will be discouraged, things change from a site to another and never are exactly as in the manual. After few days of difficult survey, you will be able to know your soil even without doing a hole. Be patient and follow what it is indicated in the published first eight articles of Humusica (http://intra.tesaf.unipd.it/people/zanella/hmanual.html). On the poster, you find some examples of diagnostic properties of forest topsoils, and a dichotomy key of classification, you can copy paste and take with you in the field. An iPhone application (Terrhum) allows to bring in the field the necessary information for a fast classification of the topsoil
TerrHum: an iOS application for classifying terrestrial humipedons and some considerations about soil classification
International audienceThe name TerrHum is an abbreviation of the words “Terrestrial” (not hydromorphic, not submerged) and “Humipedon” (organic and organic-mineral humus horizons). With this application, it is possible to describe and classify terrestrial forest and grassland topsoils in a system published as a Special Issue entitled “Humusica 1– Terrestrial Natural Humipedons” in the journal Applied Soil Ecology. The iOS application TerrHum allows the storage of the main content of Humusica 1 on a cellular phone. Images, diagrams and simplified tables of classification may be recalled with a few touches on the screen. Humus forms, representing five humus systems, are classified based on the vertical arrangement of diagnostic horizons and their attributes. TerrHum allows accessing specific figures that are stored in a virtual cloud and can be downloaded the first time the user recalls them. Once all figures have been opened in the device, the application is ready to use, without any further internet connection. The application is in continuous evolution
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