6,495 research outputs found
Meta SOS - A Maude Based SOS Meta-Theory Framework
Meta SOS is a software framework designed to integrate the results from the
meta-theory of structural operational semantics (SOS). These results include
deriving semantic properties of language constructs just by syntactically
analyzing their rule-based definition, as well as automatically deriving sound
and ground-complete axiomatizations for languages, when considering a notion of
behavioural equivalence. This paper describes the Meta SOS framework by
blending aspects from the meta-theory of SOS, details on their implementation
in Maude, and running examples.Comment: In Proceedings EXPRESS/SOS 2013, arXiv:1307.690
First steps towards the certification of an ARM simulator using Compcert
The simulation of Systems-on-Chip (SoC) is nowadays a hot topic because,
beyond providing many debugging facilities, it allows the development of
dedicated software before the hardware is available. Low-consumption CPUs such
as ARM play a central role in SoC. However, the effectiveness of simulation
depends on the faithfulness of the simulator. To this effect, we propose here
to prove significant parts of such a simulator, SimSoC. Basically, on one hand,
we develop a Coq formal model of the ARM architecture while on the other hand,
we consider a version of the simulator including components written in
Compcert-C. Then we prove that the simulation of ARM operations, according to
Compcert-C formal semantics, conforms to the expected formal model of ARM. Size
issues are partly dealt with using automatic generation of significant parts of
the Coq model and of SimSoC from the official textual definition of ARM.
However, this is still a long-term project. We report here the current stage of
our efforts and discuss in particular the use of Compcert-C in this framework.Comment: First International Conference on Certified Programs and Proofs 7086
(2011
Evolutionary improvement of programs
Most applications of genetic programming (GP) involve the creation of an entirely new function, program or expression to solve a specific problem. In this paper, we propose a new approach that applies GP to improve existing software by optimizing its non-functional properties such as execution time, memory usage, or power consumption. In general, satisfying non-functional requirements is a difficult task and often achieved in part by optimizing compilers. However, modern compilers are in general not always able to produce semantically equivalent alternatives that optimize non-functional properties, even if such alternatives are known to exist: this is usually due to the limited local nature of such optimizations. In this paper, we discuss how best to combine and extend the existing evolutionary methods of GP, multiobjective optimization, and coevolution in order to improve existing software. Given as input the implementation of a function, we attempt to evolve a semantically equivalent version, in this case optimized to reduce execution time subject to a given probability distribution of inputs. We demonstrate that our framework is able to produce non-obvious optimizations that compilers are not yet able to generate on eight example functions. We employ a coevolved population of test cases to encourage the preservation of the function's semantics. We exploit the original program both through seeding of the population in order to focus the search, and as an oracle for testing purposes. As well as discussing the issues that arise when attempting to improve software, we employ rigorous experimental method to provide interesting and practical insights to suggest how to address these issues
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
Formal executable descriptions of biological systems
The similarities between systems of living entities and systems of concurrent processes may support biological experiments in silico. Process calculi offer a formal framework to describe biological systems, as well as to analyse their behaviour, both from a qualitative and a quantitative point of view. A couple of little examples help us in showing how this can be done. We mainly focus our attention on the qualitative and quantitative aspects of the considered biological systems, and briefly illustrate which kinds of analysis are possible. We use a known stochastic calculus for the first example. We then present some statistics collected by repeatedly running the specification, that turn out to agree with those obtained by experiments in vivo. Our second example motivates a richer calculus. Its stochastic extension requires a non trivial machinery to faithfully reflect the real dynamic behaviour of biological systems
Dependability Analysis of Control Systems using SystemC and Statistical Model Checking
Stochastic Petri nets are commonly used for modeling distributed systems in
order to study their performance and dependability. This paper proposes a
realization of stochastic Petri nets in SystemC for modeling large embedded
control systems. Then statistical model checking is used to analyze the
dependability of the constructed model. Our verification framework allows users
to express a wide range of useful properties to be verified which is
illustrated through a case study
Extending the DEVS Formalism with Initialization Information
DEVS is a popular formalism to model system behaviour using a discrete-event
abstraction. The main advantages of DEVS are its rigourous and precise
specification, as well as its support for modular, hierarchical construction of
models. DEVS frequently serves as a simulation "assembly language" to which
models in other formalisms are translated, either giving meaning to new
(domain-specific) languages, or reproducing semantics of existing languages.
Despite this rigourous definition of its syntax and semantics, initialization
of DEVS models is left unspecified in both the Classic and Parallel DEVS
formalism definition. In this paper, we extend the DEVS formalism by including
an initial total state. Extensions to syntax as well as denotational (closure
under coupling) and operational semantics (abstract simulator) are presented.
The extension is applicable to both main variants of the DEVS formalism. Our
extension is such that it adds to, but does not alter the original
specification. All changes are illustrated by means of a traffic light example
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