scholarly journals Is your Model Checker on Time? On the Complexity of Model Checking for Timed Modal Logics

1999 ◽  
Vol 6 (32) ◽  
Author(s):  
Luca Aceto ◽  
Francois Laroussinie

This paper studies the structural complexity of model checking<br />for (variations on) the specification formalisms used in the tools CMC<br />and Uppaal, and fragments of a timed alternation-free mu-calculus. For<br />each of the logics we study, we characterize the computational complexity<br />of model checking, as well as its specification and program complexity,<br />using timed automata as our system model.

2000 ◽  
Vol 7 (3) ◽  
Author(s):  
Fredrik Larsson ◽  
Paul Pettersson ◽  
Wang Yi

A major problem in model-checking timed systems is the<br />huge memory requirement. In this paper, we study the memory-block<br />traversal problems of using standard operating systems in exploring the<br />state-space of timed automata. We report a case study which demonstrates<br />that deallocating memory blocks (i.e. memory-block traversal)<br />using standard memory management routines is extremely time-consuming.<br />The phenomenon is demonstrated in a number of experiments by<br />installing the Uppaal tool on Windows95, SunOS 5 and Linux. It seems<br />that the problem should be solved by implementing a memory manager<br />for the model-checker, which is a troublesome task as it is involved in<br />the underlining hardware and operating system. We present an alternative<br />technique that allows the model-checker to control the memory-block<br />traversal strategies of the operating systems without implementing<br />an independent memory manager. The technique is implemented in the<br />Uppaal model-checker. Our experiments demonstrate that it results in<br />significant improvement on the performance of Uppaal. For example, it<br />reduces the memory deallocation time in checking a start-up synchronisation<br />protocol on Linux from 7 days to about 1 hour. We show that the<br />technique can also be applied in speeding up re-traversals of explored<br />state-space.


Author(s):  
Guillermo Rodriguez-Navas ◽  
Julian Proenza ◽  
Hans Hansson ◽  
Paul Pettersson

Model checking is a widely used technique for the formal verification of computer systems. However, the suitability of model checking strongly depends on the capacity of the system designer to specify a model that captures the real behaviour of the system under verification. For the case of real-time systems, this means being able to realistically specify not only the functional aspects, but also the temporal behaviour of the system. This chapter is dedicated to modeling clocks in distributed embedded systems using the timed automata formalism. The different types of computer clocks that may be used in a distributed embedded system and their effects on the temporal behaviour of the system are introduced, together with a systematic presentation of how the behaviour of each kind of clock can be modeled. The modeling is particularized for the UPPAAL model checker, although it can be easily adapted to other model checkers based on the theory of timed automata.


2001 ◽  
Vol 8 (5) ◽  
Author(s):  
Thomas S. Hune ◽  
Judi Romijn ◽  
Mariëlle Stoelinga ◽  
Frits W. Vaandrager

<p>We present an extension of the model checker Uppaal capable<br /> of synthesizing linear parameter constraints for the correctness of<br />parametric timed automata. The symbolic representation of the (parametric)<br /> state-space is shown to be correct. A second contribution of this<br />paper is the identification of a subclass of parametric timed automata<br />(L/U automata), for which the emptiness problem is decidable, contrary<br />to the full class where it is know to be undecidable. Also we present a<br />number of lemmas enabling the verification effort to be reduced for L/U<br />automata in some cases. We illustrate our approach by deriving linear<br />parameter constraints for a number of well-known case studies from the<br />literature (exhibiting a flaw in a published paper).</p>


Author(s):  
Étienne André

AbstractReal-time systems are notoriously hard to verify due to nondeterminism, concurrency and timing constraints. When timing constants are uncertain (in early the design phase, or due to slight variations of the timing bounds), timed model checking techniques may not be satisfactory. In contrast, parametric timed model checking synthesizes timing values ensuring correctness. takes as input an extension of parametric timed automata (PTAs), a powerful formalism to formally verify critical real-time systems. extends PTAs with multi-rate clocks, global rational-valued variables and a set of additional useful features. We describe here the new features and algorithms offered by  3, that moved along the years from a simple prototype dedicated to robustness analysis to a standalone parametric model checker for timed systems.


2007 ◽  
Vol 10 (2) ◽  
Author(s):  
Gregorio Dıaz ◽  
Emilia M. Cambronero ◽  
Juan J. Pardo ◽  
Valentın Valero ◽  
Fernando Cuartero

In previous work we have presented the generation of WS-CDL and WS-BPEL documents. In this paper we show the unification of both generations. The aim is to generate correct WS-BPEL skeleton documents from WS-CDL documents by using the Timed Automata as an intermediary model in order to check the correctness of the generated Web Services with Model Checking Techniques. The model checker used is UPPAAL, a well known tool in theoretical and industrial cases that performs the verification and validation of Timed Automata. Note that our interest is focused on Web services where the time constraints play a critical role.


Author(s):  
Rachmat Wahid Saleh Insani ◽  
Reza Pulungan

Information and Communication Technology systems is a most important part of society.  These systems are becoming more and more complex and are massively encroaching on daily life via the Internet and all kinds of embedded systems. Communication protocols are one of the ICT systems used by Internet users. OLSR protocol is a wireless network communication protocol with proactive, and based on link-state algorithm. EE-OLSR protocol is a variant of OLSR that is able to prolong the network lifetime without losses of performance.Protocol verification process generally be done by simulation and testing. However, these processes unable to verify there are no subtle error or design flaw in protocol. Model Checking is an algorithmic method runs in fully automatic to verify a system. UPPAAL is a model checker tool to model, verify, and simulate a system in Timed Automata.UPPAAL CORA is model checker tool to verify EE-OLSR protocol modelled in Linearly Priced Timed Automata, if the protocol satisfy the energy efficient property formulated by formal specification language in Weighted Computation Tree Logic syntax. Model Checking Technique to verify the protocols results in the protocol is satisfy the energy efficient property only when the packet transmission traffic happens.


Author(s):  
Natasha Alechina ◽  
Hans van Ditmarsch ◽  
Rustam Galimullin ◽  
Tuo Wang

AbstractCoalition announcement logic (CAL) is one of the family of the logics of quantified announcements. It allows us to reason about what a coalition of agents can achieve by making announcements in the setting where the anti-coalition may have an announcement of their own to preclude the former from reaching its epistemic goals. In this paper, we describe a PSPACE-complete model checking algorithm for CAL that produces winning strategies for coalitions. The algorithm is implemented in a proof-of-concept model checker.


Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 223
Author(s):  
Yen-Ling Tai ◽  
Shin-Jhe Huang ◽  
Chien-Chang Chen ◽  
Henry Horng-Shing Lu

Nowadays, deep learning methods with high structural complexity and flexibility inevitably lean on the computational capability of the hardware. A platform with high-performance GPUs and large amounts of memory could support neural networks having large numbers of layers and kernels. However, naively pursuing high-cost hardware would probably drag the technical development of deep learning methods. In the article, we thus establish a new preprocessing method to reduce the computational complexity of the neural networks. Inspired by the band theory of solids in physics, we map the image space into a noninteraction physical system isomorphically and then treat image voxels as particle-like clusters. Then, we reconstruct the Fermi–Dirac distribution to be a correction function for the normalization of the voxel intensity and as a filter of insignificant cluster components. The filtered clusters at the circumstance can delineate the morphological heterogeneity of the image voxels. We used the BraTS 2019 datasets and the dimensional fusion U-net for the algorithmic validation, and the proposed Fermi–Dirac correction function exhibited comparable performance to other employed preprocessing methods. By comparing to the conventional z-score normalization function and the Gamma correction function, the proposed algorithm can save at least 38% of computational time cost under a low-cost hardware architecture. Even though the correction function of global histogram equalization has the lowest computational time among the employed correction functions, the proposed Fermi–Dirac correction function exhibits better capabilities of image augmentation and segmentation.


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