216,264 research outputs found
Runtime Enforcement for Component-Based Systems
Runtime enforcement is an increasingly popular and effective dynamic
validation technique aiming to ensure the correct runtime behavior (w.r.t. a
formal specification) of systems using a so-called enforcement monitor. In this
paper we introduce runtime enforcement of specifications on component-based
systems (CBS) modeled in the BIP (Behavior, Interaction and Priority)
framework. BIP is a powerful and expressive component-based framework for
formal construction of heterogeneous systems. However, because of BIP
expressiveness, it remains difficult to enforce at design-time complex
behavioral properties.
First we propose a theoretical runtime enforcement framework for CBS where we
delineate a hierarchy of sets of enforceable properties (i.e., properties that
can be enforced) according to the number of observational steps a system is
allowed to deviate from the property (i.e., the notion of k-step
enforceability). To ensure the observational equivalence between the correct
executions of the initial system and the monitored system, we show that i) only
stutter-invariant properties should be enforced on CBS with our monitors, ii)
safety properties are 1-step enforceable. Given an abstract enforcement monitor
(as a finite-state machine) for some 1-step enforceable specification, we
formally instrument (at relevant locations) a given BIP system to integrate the
monitor. At runtime, the monitor observes and automatically avoids any error in
the behavior of the system w.r.t. the specification. Our approach is fully
implemented in an available tool that we used to i) avoid deadlock occurrences
on a dining philosophers benchmark, and ii) ensure the correct placement of
robots on a map.Comment: arXiv admin note: text overlap with arXiv:1109.5505 by other author
Five-Brane Effective Action In M-Theory
On the world-volume of an -theory five-brane propagates a two-form with
self-dual field strength. As this field is non-Lagrangian, there is no obvious
framework for determining its partition function. An analogous problem exists
in Type IIB superstring theory for the self-dual five-form. The resolution of
these problems and definition of the partition function is explained. A more
complete analysis of perturbative anomaly cancellation for -theory
five-branes is also presented, uncovering some surprising details.Comment: 41 pp, harvma
Gibbs-non-Gibbs properties for n-vector lattice and mean-field models
We review some recent developments in the study of Gibbs and non-Gibbs
properties of transformed n-vector lattice and mean-field models under various
transformations. Also, some new results for the loss and recovery of the Gibbs
property of planar rotor models during stochastic time evolution are presented.Comment: 31 pages, 6 figure
Remark about Non-BPS D-Brane in Type IIA Theory
In this paper we would like to show simple mechanisms how from the action for
non-BPS D-brane we can obtain action describing BPS D(p-1)-brane in Type IIA
theory.Comment: 13 pages, completely rewritten pape
Geometry of N=1 Super Yang-Mills Theory in Curved Superspace
We give a new description of N=1 super Yang-Mills theory in curved
superspace. It is based on the induced geometry approach to a curved superspace
in which it is viewed as a surface embedded into C(4|2). The complex structure
on C(4|2) supplied with a standard volume element induces a special
Cauchy-Riemann (SCR)-structure on the embedded surface. We give an explicit
construction of SYM theory in terms of intrinsic geometry of the superspace
defined by this SCR-structure and a CR-bundle over the superspace. We write a
manifestly SCR-covariant Lagrangian for SYM coupled with matter. We also show
that in a special gauge our formulation coincides with the standard one which
uses Lorentz connections. Some useful auxiliary results about the integration
over surfaces in superspace are obtained.Comment: 16 pages, Late
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