Automatic Verification of Parameterized Systems by Over-Approximation PDF Download

Author: Vladislavs Jahundovics
Publisher: Linköping University Electronic Press
ISBN: 9176859185
Category :
Languages : en
Pages : 155

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Book Description
This thesis presents a completely automatic verification framework to check safety properties of parameterized systems. A parameterized system is a family of finite state systems where every system consists of a finite number of processes running in parallel the same algorithm. All the systems in the family differ only in the number of the processes and, in general, the number of systems in a family may be unbounded. Examples of parameterized systems are communication protocols, mutual exclusion protocols, cache coherence protocols, distributed algorithms etc. Model-checking of finite state systems is a well-developed formal verification approach of proving properties of systems in an automatic way. However, it cannot be applied directly to parameterized systems because the unbounded number of systems in a family means an infinite state space. In this thesis we propose to abstract an original family of systems consisting of an unbounded number of processes into one consisting of a fixed number of processes. An abstracted system is considered to consist of k+1 components—k reference processes and their environment. The transition relation for the abstracted system is an over-approximation of the transition relation for the original system, therefore, a set of reachable states of the abstracted system is an over-approximation of the set of reachable states of the original one. A safety property is considered to be parameterized by a fixed number of processes whose relationship is in the center of attention in the property. Such processes serve as reference processes in the abstraction. We propose an encoding which allows to perform reachability analysis for an abstraction parameterized by the reference processes. We have successfully verified three classic parameterized systems with replicated processes by applying this method.

Author: Francesco Logozzo
Publisher: Springer
ISBN: 3540781633
Category : Computers
Languages : en
Pages : 333

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Book Description
This book contains the proceedings of VMCAI 2007. It features current research from the communities of verification, program certification, model checking, debugging techniques, abstract interpretation, abstract domains, and advancement of hybrid methods.

Author: Kenji Suzuki
Publisher: Springer Science & Business Media
ISBN: 3540688544
Category : Computers
Languages : en
Pages : 351

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Book Description
This volume contains the proceedings of FORTE 2008, 28th IFIP WG6.1 - ternational Conference on Formal Techniques for Networked and Distributed Systems. FORTE 2008 was held at the Campus Innovation Center in Tokyo, Japan during June 10–13, 2008. FORTE denotes a series of international wo- ing conferences on formal description techniques applied to computer networks and distributed systems. The conference series started in 1981 under the name PSTV. In 1988 a second series under the name FORTE was set up. Both - ries were united to FORTE/PSTV in 1996. In 2001 the conference changed the name to its current form. Recent conferences of this long series were held in Berlin (2003), Madrid(2004), Taipei(2005), Paris(2006), and Tallinn(2007). As in the previous year, FORTE 2008 was collocated with TESTCOM/ FATES 2008: the 20th IFIP International Conference on Testing of Com- nicating Systems (TESTCOM) and the 8th International Workshop on Formal Approaches to Testing of Software (FATES). The co-location of FORTE and TESTCOM/FATES fostered the collaboration between their communities. The commonspiritofboth conferenceswasunderpinnedby jointopening andclosing sessions, invited talks, as well as joint social events.

Author: David Lee
Publisher: Springer Science & Business Media
ISBN: 3642021379
Category : Computers
Languages : en
Pages : 260

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Book Description
This book constitutes the refereed proceedings of the 11th IFIP WG 6.1 International Conference on Formal Methods for Open Object-Based Distributed Systems, FMOODS 2009, and 29th IFIP WG 6.1 Formal Techniques for Networked and Distributed Systems, FORTE 2009, held in Lisboa, Portugal, in June 2009. The 12 revised full papers presented together with 6 short papers were carefully reviewed and selected from 42 submissions. The papers cover topics such as formal verification, algorithms and implementations, modeling and testing, process algebra and calculus as well as analysis of distributed systems.

Author: Paul Gastin
Publisher: Springer Science & Business Media
ISBN: 3642153747
Category : Computers
Languages : en
Pages : 613

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Book Description
This book constitutes the refereed proceedings of the 20th International Conference on Concurrency Theory, CONCUR 2010, held in Paris, France, August 31 - September 3, 2010. The 35 revised full papers were carefully reviewed and selected from 107 submissions. The topics include: - Basic models of concurrency such as abstract machines, domain theoretic models, game theoretic models, process algebras, and Petri nets. - Logics for concurrency such as modal logics, probabilistic and stochastic logics, temporal logics, and resource logics. - Models of specialized systems such as biology-inspired systems, circuits, hybrid systems, mobile and collaborative systems, multi-core processors, probabilistic systems, real-time systems, service-oriented computing, and synchronous systems. - Verification and analysis techniques for concurrent systems such as abstract interpretation, atomicity checking, model checking, race detection, pre-order and equivalence checking and run-time verification.

Author: John Törnblom
Publisher: Linköping University Electronic Press
ISBN: 917929748X
Category :
Languages : en
Pages : 22

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Book Description
In the presence of data and computational resources, machine learning can be used to synthesize software automatically. For example, machines are now capable of learning complicated pattern recognition tasks and sophisticated decision policies, two key capabilities in autonomous cyber-physical systems. Unfortunately, humans find software synthesized by machine learning algorithms difficult to interpret, which currently limits their use in safety-critical applications such as medical diagnosis and avionic systems. In particular, successful deployments of safety-critical systems mandate the execution of rigorous verification activities, which often rely on human insights, e.g., to identify scenarios in which the system shall be tested. A natural pathway towards a viable verification strategy for such systems is to leverage formal verification techniques, which, in the presence of a formal specification, can provide definitive guarantees with little human intervention. However, formal verification suffers from scalability issues with respect to system complexity. In this thesis, we investigate the limits of current formal verification techniques when applied to a class of machine learning models called tree ensembles, and identify model-specific characteristics that can be exploited to improve the performance of verification algorithms when applied specifically to tree ensembles. To this end, we develop two formal verification techniques specifically for tree ensembles, one fast and conservative technique, and one exact but more computationally demanding. We then combine these two techniques into an abstraction-refinement approach, that we implement in a tool called VoTE (Verifier of Tree Ensembles). Using a couple of case studies, we recognize that sets of inputs that lead to the same system behavior can be captured precisely as hyperrectangles, which enables tractable enumeration of input-output mappings when the input dimension is low. Tree ensembles with a high-dimensional input domain, however, seems generally difficult to verify. In some cases though, conservative approximations of input-output mappings can greatly improve performance. This is demonstrated in a digit recognition case study, where we assess the robustness of classifiers when confronted with additive noise.

Author: John S. Fitzgerald
Publisher: Springer
ISBN: 3540857621
Category : Computers
Languages : en
Pages : 466

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Book Description
Research on theoretical aspects of computing has a direct impact on the pr- tice of computer systems development. Over many decades, fundamental t- ories have emerged to describe functionality, temporal behavior and resource consumption. Theories of application domains are beginning to be exploited for modelling and analyzing intended computing systems before the expensive c- mitment is made to real programs and hardware. Recent years have seen major improvements in the cost-e?ectiveness of tools supporting the exploitation of theories through proof, model-checking and testing. Against this encouraging background, we are pleased to present papers that show something of the live- ness and diversity of research in theoretical aspects of computing today. ICTAC 2008, the 5th International Colloquium on Theoretical Aspects of Computing, was held on 1-3 September 2008 in Istanbul, Turkey, hosted by - banc? University. The ICTAC series was founded by the International Institute for SoftwareTechnologyof the United Nations University(UNU-IIST). It brings together practitioners and researchers from academia, industry and government to present results and to exchange ideas and experience addressing challenges in both theoretical aspects of computing and in the exploitation of theory through methodsandtoolsforsystemdevelopment. Theseriesalsopromotescooperation in research and education between participants and their institutions, from - veloping and industrial countries, in accordance with the mandate of the United Nations University. The previous ICTAC colloquia were held in Guiyang, China (2004, LNCS 3407), Hanoi, Vietnam (2005, LNCS 3722), Tunis, Tunisia (2006, LNCS 4281) and Macau SAR, China (2007, LNCS 4711).

Author: Alessandro Gianola
Publisher: Springer Nature
ISBN: 3031427467
Category : Computers
Languages : en
Pages : 335

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Book Description
This book is a revised version of the PhD dissertation written by the author at the Free University of Bozen-Bolzano in Italy. It presents a new approach to safety verification of a particular class of infinite-state systems, called Data-Aware Processes (DAPs). To do so, the developed technical machinery requires to devise novel results for uniform interpolation and its combination in the context of automated reasoning. These results are then applied to the analysis of concrete business processes enriched with real data. In 2022, the PhD dissertation won the “BPM Dissertation Award”, granted to outstanding PhD theses in the field of Business Process Management.

Author: Klervie Toczé
Publisher: Linköping University Electronic Press
ISBN: 9179299040
Category :
Languages : en
Pages : 148

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Book Description
The increasing diversity of connected devices leads to new application domains being envisioned. Some of these need ultra low latency or have privacy requirements that cannot be satisfied by the current cloud. By bringing resources closer to the end user, the recent edge computing paradigm aims to enable such applications. One critical aspect to ensure the successful deployment of the edge computing paradigm is efficient resource management. Indeed, obtaining the needed resources is crucial for the applications using the edge, but the resource picture of this paradigm is complex. First, as opposed to the nearly infinite resources provided by the cloud, the edge devices have finite resources. Moreover, different resource types are required depending on the applications and the devices supplying those resources are very heterogeneous. This thesis studies several challenges towards enabling efficient resource management for edge computing. The thesis begins by a review of the state-of-the-art research focusing on resource management in the edge computing context. A taxonomy is proposed for providing an overview of the current research and identify areas in need of further work. One of the identified challenges is studying the resource supply organization in the case where a mix of mobile and stationary devices is used to provide the edge resources. The ORCH framework is proposed as a means to orchestrate this edge device mix. The evaluation performed in a simulator shows that this combination of devices enables higher quality of service for latency-critical tasks. Another area is understanding the resource demand side. The thesis presents a study of the workload of a killer application for edge computing: mixed reality. The MR-Leo prototype is designed and used as a vehicle to understand the end-to-end latency, the throughput, and the characteristics of the workload for this type of application. A method for modeling the workload of an application is devised and applied to MR-Leo in order to obtain a synthetic workload exhibiting the same characteristics, which can be used in further studies.

Author: Anders Andersson
Publisher: Linköping University Electronic Press
ISBN: 9176855244
Category :
Languages : en
Pages : 39

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Book Description
Modern vehicles are complex systems. Different design stages for such a complex system include evaluation using models and submodels, hardware-in-the-loop systems and complete vehicles. Once a vehicle is delivered to the market evaluation continues by the public. One kind of tool that can be used during many stages of a vehicle lifecycle is driving simulators. The use of driving simulators with a human driver is commonly focused on driver behavior. In a high fidelity moving base driving simulator it is possible to provide realistic and repetitive driving situations using distinctive features such as: physical modelling of driven vehicle, a moving base, a physical cabin interface and an audio and visual representation of the driving environment. A desired but difficult goal to achieve using a moving base driving simulator is to have behavioral validity. In other words, A driver in a moving base driving simulator should have the same driving behavior as he or she would have during the same driving task in a real vehicle.". In this thesis the focus is on high fidelity moving base driving simulators. The main target is to improve the behavior validity or to maintain behavior validity while adding complexity to the simulator. One main assumption in this thesis is that systems closer to the final product provide better accuracy and are perceived better if properly integrated. Thus, the approach in this thesis is to try to ease incorporation of such systems using combinations of the methods hardware-in-the-loop and distributed simulation. Hardware-in-the-loop is a method where hardware is interfaced into a software controlled environment/simulation. Distributed simulation is a method where parts of a simulation at physically different locations are connected together. For some simulator laboratories distributed simulation is the only feasible option since some hardware cannot be moved in an easy way. Results presented in this thesis show that a complete vehicle or hardware-in-the-loop test laboratory can successfully be connected to a moving base driving simulator. Further, it is demonstrated that using a framework for distributed simulation eases communication and integration due to standardized interfaces. One identified potential problem is complexity in interface wrappers when integrating hardware-in-the-loop in a distributed simulation framework. From this aspect, it is important to consider the model design and the intersections between software and hardware models. Another important issue discussed is the increased delay in overhead time when using a framework for distributed simulation.