T. Mancini, F. Mari, A. Massini, I. Melatti, and E. Tronci. "On Checking Equivalence of Simulation Scripts." Journal of Logical and Algebraic Methods in Programming (2021): 100640. ISSN: 2352-2208. DOI: 10.1016/j.jlamp.2021.100640.
Abstract: To support Model Based Design of Cyber-Physical Systems (CPSs) many simulation based approaches to System Level Formal Verification (SLFV) have been devised. Basically, these are Bounded Model Checking approaches (since simulation horizon is of course bounded) relying on simulators to compute the system dynamics and thereby verify the given system properties. The main obstacle to simulation based SLFV is the large number of simulation scenarios to be considered and thus the huge amount of simulation time needed to complete the verification task. To save on computation time, simulation based SLFV approaches exploit the capability of simulators to save and restore simulation states. Essentially, such a time saving is obtained by optimising the simulation script defining the simulation activity needed to carry out the verification task. Although such approaches aim to (bounded) formal verification, as a matter of fact, the proof of correctness of the methods to optimise simulation scripts basically relies on an intuitive semantics for simulation scripting languages. This hampers the possibility of formally showing that the optimisations introduced to speed up the simulation activity do not actually omit checking of relevant behaviours for the system under verification. The aim of this paper is to fill the above gap by presenting an operational semantics for simulation scripting languages and by proving soundness and completeness properties for it. This, in turn, enables formal proofs of equivalence between unoptimised and optimised simulation scripts.
Keywords: Formal verification, Simulation based formal verification, Formal Verification of cyber-physical systems, System-level formal verification
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Rosario Pugliese, and Enrico Tronci. "Automatic Verification of a Hydroelectric Power Plant." In Third International Symposium of Formal Methods Europe (FME), Co-Sponsored by IFIP WG 14.3, edited by M. - C. Gaudel and J. Woodcock, 425–444. Lecture Notes in Computer Science 1051. Oxford, UK: Springer, 1996. ISSN: 3-540-60973-3. DOI: 10.1007/3-540-60973-3_100.
Abstract: We analyze the specification of a hydroelectric power plant by ENEL (the Italian Electric Company). Our goal is to show that for the specification of the plant (its control system in particular) some given properties hold. We were provided with an informal specification of the plant. From such informal specification we wrote a formal specification using the CCS/Meije process algebra formalism. We defined properties using μ-calculus. Automatic verification was carried out using model checking. This was done by translating our process algebra definitions (the model) and μ-calculus formulas into BDDs. In this paper we present the informal specification of the plant, its formal specification, some of the properties we verified and experimental results.
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Ruggero Lanotte, Andrea Maggiolo-Schettini, Simone Tini, Angelo Troina, and Enrico Tronci. "Automatic Analysis of the NRL Pump." Electr. Notes Theor. Comput. Sci. 99 (2004): 245–266. DOI: 10.1016/j.entcs.2004.02.011.
Abstract: We define a probabilistic model for the NRL Pump and using FHP-mur$\varphi$ show experimentally that there exists a probabilistic covert channel whose capacity depends on various NRL Pump parameters (e.g. buffer size, number of samples in the moving average, etc).
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Riccardo Focardi, Roberto Gorrieri, Ruggero Lanotte, Andrea Maggiolo-Schettini, Fabio Martinelli, Simone Tini, and Enrico Tronci. "Formal Models of Timing Attacks on Web Privacy." Electronic Notes in Theoretical Computer Science 62 (2002): 229–243. Notes: TOSCA 2001, Theory of Concurrency, Higher Order Languages and Types. DOI: 10.1016/S1571-0661(04)00329-9.
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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Enrico Tronci. "Formally Modeling a Metal Processing Plant and its Closed Loop Specifications." In 4th IEEE International Symposium on High-Assurance Systems Engineering (HASE), 151. Washington, D.C, USA: IEEE Computer Society, 1999. ISSN: 0-7695-0418-3. DOI: 10.1109/HASE.1999.809490.
Abstract: We present a case study on automatic synthesis of control software from formal specifications for an industrial automation control system. Our aim is to compare the effectiveness (i.e. design effort and controller quality) of automatic controller synthesis from closed loop formal specifications with that of manual controller design followed by automatic verification. The system to be controlled (plant) models a metal processing facility near Karlsruhe. We succeeded in automatically generating C code implementing a (correct by construction) embedded controller for such a plant from closed loop formal specifications. Our experimental results show that for industrial automation control systems automatic synthesis is a viable and profitable (especially as far as design effort is concerned) alternative to manual design followed by automatic verification.
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Enrico Tronci. "Automatic Synthesis of Control Software for an Industrial Automation Control System." In Proc.of: 14th IEEE International Conference on: Automated Software Engineering (ASE), 247–250. Cocoa Beach, Florida, USA, 1999. DOI: 10.1109/ASE.1999.802292.
Abstract: We present a case study on automatic synthesis of control software from formal specifications for an industrial automation control system. Our aim is to compare the effectiveness (i.e. design effort and controller quality) of automatic controller synthesis from closed loop formal specifications with that of manual controller design, followed by automatic verification. Our experimental results show that for industrial automation control systems, automatic synthesis is a viable and profitable (especially as far as design effort is concerned) alternative to manual design, followed by automatic verification.
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Giuseppe Della Penna, Daniele Magazzeni, Alberto Tofani, Benedetto Intrigila, Igor Melatti, and Enrico Tronci. "Automated Generation of Optimal Controllers through Model Checking Techniques." In Icinco-Icso, edited by J. Andrade-Cetto, J. - L. Ferrier, J. M. C. D. Pereira and J. Filipe, 26–33. INSTICC Press, 2006. ISSN: 972-8865-59-7. DOI: 10.1007/978-3-540-79142-3.
Abstract: We present a methodology for the synthesis of controllers, which exploits (explicit) model checking techniques. That is, we can cope with the systematic exploration of a very large state space. This methodology can be applied to systems where other approaches fail. In particular, we can consider systems with an highly non-linear dynamics and lacking a uniform mathematical description (model). We can also consider situations where the required control action cannot be specified as a local action, and rather a kind of planning is required. Our methodology individuates first a raw optimal controller, then extends it to obtain a more robust one. A case study is presented which considers the well known truck-trailer obstacle avoidance parking problem, in a parking lot with obstacles on it. The complex non-linear dynamics of the truck-trailer system, within the presence of obstacles, makes the parking problem extremely hard. We show how, by our methodology, we can obtain optimal controllers with different degrees of robustness.
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Federico Cavaliere, Federico Mari, Igor Melatti, Giovanni Minei, Ivano Salvo, Enrico Tronci, Giovanni Verzino, and Yuri Yushtein. "Model Checking Satellite Operational Procedures." In DAta Systems In Aerospace (DASIA), Org. EuroSpace, Canadian Space Agency, CNES, ESA, EUMETSAT. San Anton, Malta, EuroSpace., 2011.
Abstract: We present a model checking approach for the automatic verification of satellite operational procedures (OPs). Building a model for a complex system as a satellite is a hard task. We overcome this obstruction by using a suitable simulator (SIMSAT) for the satellite. Our approach aims at improving OP quality assurance by automatic exhaustive exploration of all possible simulation scenarios. Moreover, our solution decreases OP verification costs by using a model checker (CMurphi) to automatically drive the simulator. We model OPs as user-executed programs observing the simulator telemetries and sending telecommands to the simulator. In order to assess feasibility of our approach we present experimental results on a simple meaningful scenario. Our results show that we can save up to 90% of verification time.
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Federico Mari, Igor Melatti, Ivano Salvo, Enrico Tronci, Lorenzo Alvisi, Allen Clement, and Harry Li. "Model Checking Nash Equilibria in MAD Distributed Systems." In FMCAD '08: Proceedings of the 2008 International Conference on Formal Methods in Computer-Aided Design, edited by A. Cimatti and R. Jones, 1–8. Piscataway, NJ, USA: IEEE Press, 2008. ISSN: 978-1-4244-2735-2. DOI: 10.1109/FMCAD.2008.ECP.16.
Abstract: We present a symbolic model checking algorithm for verification of Nash equilibria in finite state mechanisms modeling Multiple Administrative Domains (MAD) distributed systems. Given a finite state mechanism, a proposed protocol for each agent and an indifference threshold for rewards, our model checker returns PASS if the proposed protocol is a Nash equilibrium (up to the given indifference threshold) for the given mechanism, FAIL otherwise. We implemented our model checking algorithm inside the NuSMV model checker and present experimental results showing its effectiveness for moderate size mechanisms. For example, we can handle mechanisms which corresponding normal form games would have more than $10^20$ entries. To the best of our knowledge, no model checking algorithm for verification of mechanism Nash equilibria has been previously published.
Keywords: Model Checking, MAD Distributed System, Nash Equilibrium
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Giuseppe Della Penna, Benedetto Intrigila, Igor Melatti, Enrico Tronci, and Marisa Venturini Zilli. "Integrating RAM and Disk Based Verification within the Mur$\varphi$ Verifier." In Correct Hardware Design and Verification Methods, 12th IFIP WG 10.5 Advanced Research Working Conference, CHARME 2003, L'Aquila, Italy, October 21-24, 2003, Proceedings, edited by D. Geist and E. Tronci, 277–282. Lecture Notes in Computer Science 2860. Springer, 2003. ISSN: 3-540-20363-X. DOI: 10.1007/978-3-540-39724-3_25.
Abstract: We present a verification algorithm that can automatically switch from RAM based verification to disk based verification without discarding the work done during the RAM based verification phase. This avoids having to choose beforehand the proper verification algorithm. Our experimental results show that typically our integrated algorithm is as fast as (sometime faster than) the fastest of the two base (i.e. RAM based and disk based) verification algorithms.
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