Results 11  20
of
22
Metric Denotational Semantics for PEPA
 Proceedings of the Fourth Annual Workshop on Process Algebra and Performance Modelling
, 1996
"... Stochastic process algebras, which combine the features of a process calculus with stochastic analysis, were introduced to enable compositional performance analysis of systems. At the level of syntax, compositionality presents itself in terms of operators, which can be used to build more complex sys ..."
Abstract

Cited by 5 (1 self)
 Add to MetaCart
Stochastic process algebras, which combine the features of a process calculus with stochastic analysis, were introduced to enable compositional performance analysis of systems. At the level of syntax, compositionality presents itself in terms of operators, which can be used to build more complex systems from simple components. Denotational semantics is a method for assigning to syntactic objects elements of a suitably chosen semantic domain. This is compositional in style, as operators are represented by certain functions on the domain, and often allows to gain additional insight by considering the properties of those functions. We consider Performance Evaluation Process Algebra (PEPA), a stochastic process algebra introduced by Hillston [9]. Based on the methodology introduced by de Bakker & Zucker, we give denotational semantics to PEPA by means of a complete metric space of suitably enriched trees. We investigate continuity properties of the PEPA operators and show that our semantic...
Measuring the Confinement of Concurrent Probabilistic Systems
 In Proc. of WITS’03 – 2003 IFIP WG 1.7, ACM SIGPLAN and GI FoMSESS Workshop on Issues in the Theory of Security
, 2003
"... 1 Dipartimento di Informatica, Universit'a di Pisa, Italy 2 ..."
Abstract

Cited by 3 (3 self)
 Add to MetaCart
1 Dipartimento di Informatica, Universit'a di Pisa, Italy 2
C.A.: Instruction sequence notations with probabilistic instructions
, 2009
"... Abstract. This paper concerns probabilistic instruction sequences. We use the term probabilistic instruction sequence for an instruction sequence that contains probabilistic instructions, i.e. instructions that are themselves probabilistic by nature, rather than an instruction sequence of which the ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
Abstract. This paper concerns probabilistic instruction sequences. We use the term probabilistic instruction sequence for an instruction sequence that contains probabilistic instructions, i.e. instructions that are themselves probabilistic by nature, rather than an instruction sequence of which the instructions are intended to be processed in a probabilistic way. We propose several kinds of probabilistic instructions, provide an informal operational meaning for each of them, and discuss related work. On purpose, we refrain from providing an ad hoc formal meaning for the proposed kinds of instructions.
GSOS for probabilistic transition systems (Extended Abstract)
, 2002
"... We introduce probabilistic GSOS, an operator specification format for (reactive) probabilistic transition systems which arises as an adaptation of the known GSOS format for labelled (nondeterministic) transition systems. Like the standard one, the format is well behaved in the sense that on all mode ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
We introduce probabilistic GSOS, an operator specification format for (reactive) probabilistic transition systems which arises as an adaptation of the known GSOS format for labelled (nondeterministic) transition systems. Like the standard one, the format is well behaved in the sense that on all models bisimilarity is a congruence and the uptocontext proof principle is valid. Moreover, every specification has a final model which can be shown to offer unique solutions for guarded recursive equations. The format covers operator specifications from the literature, so that the wellbehavedness results given for those arise as instances of our general one.
Building Metric Structures with the MeasFunctor
"... We introduce the functor Meas in the category of complete ultra metric spaces and nonexpansive mapping. The main result of this paper is that Meas is a wellde ned and locally nonexpansive endofunctor. Therefore the functor ts naturally in the metric approach to programming language semantics. ..."
Abstract
 Add to MetaCart
We introduce the functor Meas in the category of complete ultra metric spaces and nonexpansive mapping. The main result of this paper is that Meas is a wellde ned and locally nonexpansive endofunctor. Therefore the functor ts naturally in the metric approach to programming language semantics. The use of Meas in the construction of probabilistic powerdomains, either directly or through the use of domain equations, is illustrated with two examples.
Including General Equilibrium Theory into FDTs: A First Approach
"... In this paper we present a process algebra to specify systems that depend, for their execution, on a set of resources that they own. Besides, in order to improve their performance, processes will be able to exchange resources between them. In order to define this new language we will borrow some ..."
Abstract
 Add to MetaCart
In this paper we present a process algebra to specify systems that depend, for their execution, on a set of resources that they own. Besides, in order to improve their performance, processes will be able to exchange resources between them. In order to define this new language we will borrow some concepts from microeconomic theory. Our language will be defined in two steps. We will assume that we have a base language to specify the behavior of processes. Then we give
A Class of Stochastic Petri Nets with Step Semantics and Related Equivalence Notions
, 2000
"... This paper presents a class of Stochastic Petri Nets with concurrent transition rings. It is assumed that transitions occur in steps and that for every step each enabled transition decides probabilistically whether it wants to participate in the step or not. Among the transitions which want to parti ..."
Abstract
 Add to MetaCart
This paper presents a class of Stochastic Petri Nets with concurrent transition rings. It is assumed that transitions occur in steps and that for every step each enabled transition decides probabilistically whether it wants to participate in the step or not. Among the transitions which want to participate in a step, a maximal number is chosen to perform the ring step. The observable behavior of a net is described by labels associated with transitions. For this class of nets the dynamic behavior is dened and equivalence relations are introduced. The equivalence relations extend the wellknown trace and bisimulation equivalences for systems with step semantics to Stochastic Petri Nets with concurrent transition ring. It is shown that the equivalence notions form a lattice of interrelations. Keywords: Stochastic Petri Nets, Step Semantics, Equivalence Relations, Bisimulation. 1 Introduction Stochastic Petri Nets (SPNs) are an established model type for the quantitative analysis of D...
On Automated Verication of Probabilistic Programs
, 2007
"... We introduce a simple procedural probabilistic programming language which is suitable for coding a wide variety of randomised algorithms and protocols. This language is interpreted over nite datatypes and has a decidable equivalence problem. We have implemented an automated equivalence checker, whic ..."
Abstract
 Add to MetaCart
We introduce a simple procedural probabilistic programming language which is suitable for coding a wide variety of randomised algorithms and protocols. This language is interpreted over nite datatypes and has a decidable equivalence problem. We have implemented an automated equivalence checker, which we call apex, for this language, based on game semantics. We illustrate our approach with three nontrivial case studies: (i) Herman's selfstabilisation algorithm; (ii) an analysis of the average shape of binary search trees obtained by certain sequences of random insertions and deletions; and (iii) the problem of anonymity in the Dining Cryptographers protocol. In particular, we record an exponential speedup in the latter over stateoftheart competing approaches. 1
Metric Semantics and Full Abstractness for Action Refinement and Probabilistic Choice
, 2001
"... This paper provides a casestudy in the eld of metric semantics for probabilistic programming. Both an operational and a denotational semantics are presented for an abstract process language L pr , which features action refinement and probabilistic choice. The two models are constructed in the setti ..."
Abstract
 Add to MetaCart
This paper provides a casestudy in the eld of metric semantics for probabilistic programming. Both an operational and a denotational semantics are presented for an abstract process language L pr , which features action refinement and probabilistic choice. The two models are constructed in the setting of complete ultrametric spaces, here based on probability measures of compact support over sequences of actions. It is shown that the standard toolkit for metric semantics works well in the probabilistic context of L pr , e.g. in establishing the correctness of the denotational semantics with respect to the operational one. In addition, it is shown how the method of proving full abstraction  as proposed recently by the authors for a nondeterministic language with action refinement  can be adapted to deal with the probabilistic language L pr as well.
PCSP: A Denotational Model of Probabilistic Processes
, 1996
"... We present a model of probabilistic processes based on an asynchronous algebra, starting from the classical CSP; replacing internal nondeterminism by generative probabilistic choices, and external nondeterminism by reactive probabilistic choices. Our purpose when defining the model has been to main ..."
Abstract
 Add to MetaCart
We present a model of probabilistic processes based on an asynchronous algebra, starting from the classical CSP; replacing internal nondeterminism by generative probabilistic choices, and external nondeterminism by reactive probabilistic choices. Our purpose when defining the model has been to maintain, as far as possible, the meaning of all the operators in classical CSP, generalizing their meaning in a probabilistic way. Thus we try to keep valid (once probabilistically generalized), as far as possible, the laws of CSP. It is the combination of both internal and external choice that makes strongly difficult the definition of a probabilistic version of CSP. We can find in the current literature quite a number of papers on probabilistic processes, but only in a few of them internal and external choices are combined, trying to preserve their original meaning. The denotational