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Author Della Penna, Giuseppe; Intrigila, Benedetto; Melatti, Igor; Tronci, Enrico; Venturini Zilli, Marisa
Title Finite Horizon Analysis of Stochastic Systems with the Mur$\varphi$ Verifier Type Conference Article
Year (down) 2003 Publication Theoretical Computer Science, 8th Italian Conference, ICTCS 2003, Bertinoro, Italy, October 13-15, 2003, Proceedings Abbreviated Journal
Volume Issue Pages 58-71
Keywords
Abstract Many reactive systems are actually Stochastic Processes. Automatic analysis of such systems is usually very difficult thus typically one simplifies the analysis task by using simulation or by working on a simplified model (e.g. a Markov Chain). We present a Finite Horizon Probabilistic Model Checking approach which essentially can handle the same class of stochastic processes of a typical simulator. This yields easy modeling of the system to be analyzed together with formal verification capabilities. Our approach is based on a suitable disk based extension of the Mur$\varphi$ verifier. Moreover we present experimental results showing effectiveness of our approach.
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Corporate Author Thesis
Publisher Springer Place of Publication Editor Blundo, C.; Laneve, C.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2841 Series Issue Edition
ISSN 3-540-20216-1 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ DIMTZ03c Serial 90
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Tronci, Enrico; Venturini Zilli, Marisa
Title Exploiting Transition Locality in the Disk Based Mur$\varphi$ Verifier Type Conference Article
Year (down) 2002 Publication 4th International Conference on Formal Methods in Computer-Aided Design (FMCAD) Abbreviated Journal
Volume Issue Pages 202-219
Keywords
Abstract The main obstruction to automatic verification of Finite State Systems is the huge amount of memory required to complete the verification task (state explosion). This motivates research on distributed as well as disk based verification algorithms. In this paper we present a disk based Breadth First Explicit State Space Exploration algorithm as well as an implementation of it within the Mur$\varphi$ verifier. Our algorithm exploits transition locality (i.e. the statistical fact that most transitions lead to unvisited states or to recently visited states) to decrease disk read accesses thus reducing the time overhead due to disk usage. A disk based verification algorithm for Mur$\varphi$ has been already proposed in the literature. To measure the time speed up due to locality exploitation we compared our algorithm with such previously proposed algorithm. Our experimental results show that our disk based verification algorithm is typically more than 10 times faster than such previously proposed disk based verification algorithm. To measure the time overhead due to disk usage we compared our algorithm with RAM based verification using the (standard) Mur$\varphi$ verifier with enough memory to complete the verification task. Our experimental results show that even when using 1/10 of the RAM needed to complete verification, our disk based algorithm is only between 1.4 and 5.3 times (3 times on average) slower than (RAM) Mur$\varphi$ with enough RAM memory to complete the verification task at hand. Using our disk based Mur$\varphi$ we were able to complete verification of a protocol with about $10^9$ reachable states. This would require more than 5 gigabytes of RAM using RAM based Mur$\varphi$.
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Corporate Author Thesis
Publisher Springer Place of Publication Portland, OR, USA Editor Aagaard, M.; O'Leary, J.W.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2517 Series Issue Edition
ISSN 3-540-00116-6 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ fmcad02 Serial 41
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Author Gribaudo, Marco; Horváth, Andras; Bobbio, Andrea; Tronci, Enrico; Ciancamerla, Ester; Minichino, Michele
Title Model-Checking Based on Fluid Petri Nets for the Temperature Control System of the ICARO Co-generative Plant Type Conference Article
Year (down) 2002 Publication 21st International Conference on Computer Safety, Reliability and Security (SAFECOMP) Abbreviated Journal
Volume Issue Pages 273-283
Keywords
Abstract The modeling and analysis of hybrid systems is a recent and challenging research area which is actually dominated by two main lines: a functional analysis based on the description of the system in terms of discrete state (hybrid) automata (whose goal is to ascertain for conformity and reachability properties), and a stochastic analysis (whose aim is to provide performance and dependability measures). This paper investigates a unifying view between formal methods and stochastic methods by proposing an analysis methodology of hybrid systems based on Fluid Petri Nets (FPN). It is shown that the same FPN model can be fed to a functional analyser for model checking as well as to a stochastic analyser for performance evaluation. We illustrate our approach and show its usefulness by applying it to a “real world†hybrid system: the temperature control system of a co-generative plant.
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Corporate Author Thesis
Publisher Springer Place of Publication Catania, Italy Editor Anderson, S.; Bologna, S.; Felici, M.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2434 Series Issue Edition
ISSN 3-540-44157-3 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ safecomp02 Serial 42
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Author Della Penna, Giuseppe; Intrigila, Benedetto; Tronci, Enrico; Venturini Zilli, Marisa
Title Synchronized Regular Expressions Type Journal Article
Year (down) 2002 Publication Electr. Notes Theor. Comput. Sci. Abbreviated Journal
Volume 62 Issue Pages 195-210
Keywords
Abstract Text manipulation is one of the most common tasks for everyone using a computer. The increasing number of textual information in electronic format that every computer user collects everyday stresses the need of more powerful tools to interact with texts. Indeed, much work has been done to provide nonprogramming tools that can be useful for the most common text manipulation issues. Regular Expressions (RE), introduced by Kleene, are well–known in the formal language theory. RE received several extensions, depending on the application of interest. In almost all the implementations of RE search algorithms (e.g. the egrep [A] UNIX command, or the Perl [17] language pattern matching constructs) we find backreferences (as defind in [1]), i.e. expressions that make reference to the string matched by a previous subexpression. Generally speaking, it seems that all the kinds of synchronizations between subexpressions in a RE can be very useful when interacting with texts. Therefore, we introduce the Synchronized Regular Expressions (SRE) as a derivation of the Regular Expressions. We use SRE to present a formal study of the already known backreferences extension, and of a new extension proposed by us, which we call the synchronized exponents. Moreover, since we are talking about formalisms that should have a practical utility and can be used in the real world, we have the problem of how to present SRE to the final users. Therefore, in this paper we also propose a user–friendly syntax for SRE to be used in implementations of SRE–powered search algorithms.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types Approved yes
Call Number Sapienza @ mari @ entcs02 Serial 46
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Author Focardi, Riccardo; Gorrieri, Roberto; Lanotte, Ruggero; Maggiolo-Schettini, Andrea; Martinelli, Fabio; Tini, Simone; Tronci, Enrico
Title Formal Models of Timing Attacks on Web Privacy Type Journal Article
Year (down) 2002 Publication Electronic Notes in Theoretical Computer Science Abbreviated Journal
Volume 62 Issue Pages 229-243
Keywords
Abstract We model a timing attack on web privacy proposed by Felten and Schneider by using three different approaches: HL-Timed Automata, SMV model checker, and tSPA Process Algebra. Some comparative analysis on the three approaches is derived.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types Approved yes
Call Number Sapienza @ mari @ entcs02a Serial 47
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Author Barbanera, Franco; Dezani-Ciancaglini, Mariangiola; Salvo, Ivano; Sassone, Vladimiro
Title A Type Inference Algorithm for Secure Ambients Type Journal Article
Year (down) 2002 Publication Electronic Notes in Theoretical Computer Science Abbreviated Journal
Volume 62 Issue Pages 83-101
Keywords
Abstract We consider a type discipline for the Ambient Calculus that associates ambients with security levels and constrains them to be traversed by or opened in ambients of higher security clearance only. We present a bottom-up algorithm that, given an untyped process P, computes a minimal set of constraints on security levels such that all actions during runs of P are performed without violating the security level priorities. Such an algorithm appears to be a prerequisite to use type systems to ensure security properties in the web scenario.
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Corporate Author Thesis
Publisher Elsevier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types Approved yes
Call Number Sapienza @ mari @ Barbanera-Dezani-Salvo-Sassone:01 Serial 73
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Author Tronci, Enrico; Della Penna, Giuseppe; Intrigila, Benedetto; Venturini Zilli, Marisa
Title A Probabilistic Approach to Automatic Verification of Concurrent Systems Type Conference Article
Year (down) 2001 Publication 8th Asia-Pacific Software Engineering Conference (APSEC) Abbreviated Journal
Volume Issue Pages 317-324
Keywords
Abstract The main barrier to automatic verification of concurrent systems is the huge amount of memory required to complete the verification task (state explosion). In this paper we present a probabilistic algorithm for automatic verification via model checking. Our algorithm trades space with time. In particular, when memory is full because of state explosion our algorithm does not give up verification. Instead it just proceeds at a lower speed and its results will only hold with some arbitrarily small error probability. Our preliminary experimental results show that by using our probabilistic algorithm we can typically save more than 30% of RAM with an average time penalty of about 100% w.r.t. a deterministic state space exploration with enough memory to complete the verification task. This is better than giving up the verification task because of lack of memory.
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Corporate Author Thesis
Publisher IEEE Computer Society Place of Publication Macau, China Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7695-1408-1 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ apsec01 Serial 43
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Author Tronci, Enrico; Della Penna, Giuseppe; Intrigila, Benedetto; Venturini Zilli, Marisa
Title Exploiting Transition Locality in Automatic Verification Type Conference Article
Year (down) 2001 Publication 11th IFIP WG 10.5 Advanced Research Working Conference on Correct Hardware Design and Verification Methods (CHARME) Abbreviated Journal
Volume Issue Pages 259-274
Keywords
Abstract In this paper we present an algorithm to contrast state explosion when using Explicit State Space Exploration to verify protocols. We show experimentally that protocols exhibit transition locality. We present a verification algorithm that exploits transition locality as well as an implementation of it within the Mur$\varphi$ verifier. Our algorithm is compatible with all Breadth First (BF) optimization techniques present in the Mur$\varphi$ verifier and it is by no means a substitute for any of them. In fact, since our algorithm trades space with time, it is typically most useful when one runs out of memory and has already used all other state reduction techniques present in the Mur$\varphi$ verifier. Our experimental results show that using our approach we can typically save more than 40% of RAM with an average time penalty of about 50% when using (Mur$\varphi$) bit compression and 100% when using bit compression and hash compaction.
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Corporate Author Thesis
Publisher Springer Place of Publication Livingston, Scotland, UK Editor Margaria, T.; Melham, T.F.
Language Summary Language Original Title
Series Editor Series Title Lecture Notes in Computer Science Abbreviated Series Title
Series Volume 2144 Series Issue Edition
ISSN 3-540-42541-1 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ charme01 Serial 44
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Author Dipoppa, G.; D'Alessandro, G.; Semprini, R.; Tronci, E.
Title Integrating Automatic Verification of Safety Requirements in Railway Interlocking System Design Type Conference Article
Year (down) 2001 Publication High Assurance Systems Engineering, 2001. Sixth IEEE International Symposium on Abbreviated Journal
Volume Issue Pages 209-219
Keywords
Abstract A railway interlocking system (RIS) is an embedded system (namely a supervisory control system) that ensures the safe, operation of the devices in a railway station. RIS is a safety critical system. We explore the possibility of integrating automatic formal verification methods in a given industry RIS design flow. The main obstructions to be overcome in our work are: selecting a formal verification tool that is efficient enough to solve the verification problems at hand; and devising a cost effective integration strategy for such tool. We were able to devise a successful integration strategy meeting the above constraints without requiring major modification in the pre-existent design flow nor retraining of personnel. We run verification experiments for a RIS designed for the Singapore Subway. The experiments show that the RIS design flow obtained from our integration strategy is able to automatically verify real life RIS designs.
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Corporate Author Thesis
Publisher IEEE Computer Society Place of Publication Albuquerque, NM, USA Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0-7695-1275-5 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ hase01 Serial 45
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Author Bobbio, Andrea; Bologna, Sandro; Minichino, Michele; Ciancamerla, Ester; Incalcaterra, Piero; Kropp, Corrado; Tronci, Enrico
Title Advanced techniques for safety analysis applied to the gas turbine control system of Icaro co generative plant Type Conference Article
Year (down) 2001 Publication X Convegno Tecnologie e Sistemi Energetici Complessi Abbreviated Journal
Volume Issue Pages 339-350
Keywords
Abstract The paper describes two complementary and integrable approaches, a probabilistic one and a deterministic one, based on classic and advanced modelling techniques for safety analysis of complex computer based systems. The probabilistic approach is based on classical and innovative probabilistic analysis methods. The deterministic approach is based on formal verification methods. Such approaches are applied to the gas turbine control system of ICARO co generative plant, in operation at ENEA CR Casaccia. The main difference between the two approaches, behind the underlining different theories, is that the probabilistic one addresses the control system by itself, as the set of sensors, processing units and actuators, while the deterministic one also includes the behaviour of the equipment under control which interacts with the control system. The final aim of the research, documented in this paper, is to explore an innovative method which put the probabilistic and deterministic approaches in a strong relation to overcome the drawbacks of their isolated, selective and fragmented use which can lead to inconsistencies in the evaluation results.
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Corporate Author Thesis
Publisher Place of Publication Genova, Italy Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Sapienza @ mari @ tesec01 Serial 65
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