Results 1 
9 of
9
From MTL to Deterministic Timed Automata
"... Abstract. In this paper we propose a novel technique for constructing timed automata from properties expressed in the logic MTL, under boundedvariability assumptions. We handle full MTL and in particular do not impose bounds on the future temporal connectives. Our construction is based on separatio ..."
Abstract

Cited by 6 (0 self)
 Add to MetaCart
Abstract. In this paper we propose a novel technique for constructing timed automata from properties expressed in the logic MTL, under boundedvariability assumptions. We handle full MTL and in particular do not impose bounds on the future temporal connectives. Our construction is based on separation of the continuous time monitoring of the input sequence and discrete predictions regarding the future. The separation of the continuous from the discrete allows us to further determinize our automata. This leads, for the first time, to a construction from full MTL to deterministic timed automata. 1
On the expressiveness of MTL variants over dense time
 In Proceedings of the 5th International Conference on Formal Modelling and Analysis of Timed Systems (FORMATS’07), Lecture Notes in Computer Science
, 2007
"... The basic modal operator bounded until of Metric Temporal Logic (MTL) comes in several variants. In particular it can be strict (when it does not constrain the current instant) or not, and matching (when it requires its two arguments to eventually hold together) or not. This paper compares the relat ..."
Abstract

Cited by 6 (3 self)
 Add to MetaCart
(Show Context)
The basic modal operator bounded until of Metric Temporal Logic (MTL) comes in several variants. In particular it can be strict (when it does not constrain the current instant) or not, and matching (when it requires its two arguments to eventually hold together) or not. This paper compares the relative expressiveness of the resulting MTL variants over dense time. We prove that the expressiveness is not affected by the variations when considering nonZeno interpretations and arbitrary nesting of temporal operators. On the contrary, the expressiveness changes for flat
Realizability of RealTime Logics
"... We study the realizability problem for specifications of reactive systems expressed in realtime linear temporal logics. The logics we consider are subsets of MITL (Metric Interval Temporal Logic), a logic for which the satisfiability and validity problems are decidable, a necessary condition for t ..."
Abstract

Cited by 4 (3 self)
 Add to MetaCart
(Show Context)
We study the realizability problem for specifications of reactive systems expressed in realtime linear temporal logics. The logics we consider are subsets of MITL (Metric Interval Temporal Logic), a logic for which the satisfiability and validity problems are decidable, a necessary condition for the realizability problem to be decidable. On the positive side, we show that the realizability of LTL extended with past realtime formulas is decidable in 2EXPTIME, with a matching lower bound. On the negative side, we show that a simple extension of this decidable fragment with future realtime formulas leads to undecidability. In particular, our results imply that the realizability problem is undecidable for ECL (Event Clock Logic), and therefore also for MITL.
RewriteBased Statistical Model Checking of WMTL
"... Abstract. We present a new technique for verifying Weighted Metric Temporal Logic (WMTL) properties of Weighted Timed Automata. Our approach relies on Statistical Model Checking combined with a new monitoring algorithm based on rewriting rules. Contrary to existing monitoring approaches for WMTL o ..."
Abstract

Cited by 3 (3 self)
 Add to MetaCart
(Show Context)
Abstract. We present a new technique for verifying Weighted Metric Temporal Logic (WMTL) properties of Weighted Timed Automata. Our approach relies on Statistical Model Checking combined with a new monitoring algorithm based on rewriting rules. Contrary to existing monitoring approaches for WMTL ours is exact. The technique has been implemented in the statistical model checking engine of Uppaal and experiments indicate that the technique performs faster than existing approaches and leads to more accurate results. 1
Towards realtime, onboard, hardwaresupported sensor and software health management for unmanned aerial systems
 in Proceedings of the 2013 Annual Conference of the Prognostics and Health Management Society (PHM2013
, 2013
"... Unmanned aerial systems (UASs) can only be deployed if they can effectively complete their missions and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. In this paper, we design a realt ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
(Show Context)
Unmanned aerial systems (UASs) can only be deployed if they can effectively complete their missions and respond to failures and uncertain environmental conditions while maintaining safety with respect to other aircraft as well as humans and property on the ground. In this paper, we design a realtime, onboard system health management (SHM) capability to continuously monitor sensors, software, and hardware components for detection and diagnosis of failures and violations of safety or performance rules during the flight of a UAS. Our approach to SHM is threepronged, providing: (1) realtime monitoring of sensor and/or software signals; (2) signal analysis, preprocessing, and advanced onthefly temporal and Bayesian probabilistic fault diagnosis; (3) an unobtrusive, lightweight, readonly, lowpower real
Timed Pattern Matching
"... Abstract. Given a timed regular expression and a densetime Boolean signal we compute the set of all matches of the expression in the signal, that is, the set of all segments of the signal that satisfy the regular expression. The set of matches is viewed as a set of points in a twodimensional space ..."
Abstract

Cited by 1 (1 self)
 Add to MetaCart
(Show Context)
Abstract. Given a timed regular expression and a densetime Boolean signal we compute the set of all matches of the expression in the signal, that is, the set of all segments of the signal that satisfy the regular expression. The set of matches is viewed as a set of points in a twodimensional space with each point indicating the beginning and end of a matching segment on the real time axis. Our procedure, which works by induction on the structure of the expression, is based on the following result that we prove in this paper: the set of all matches of a timed regular expression by a signal of finite variability and duration can be written as a finite union of zones. 1
Online Monitoring of Metric Temporal Logic
"... Abstract. Current approaches to monitoring realtime properties suffer either from unbounded space requirements or lack of expressiveness. In this paper, we adapt a separation technique enabling us to rewrite arbitrary MTL formulas into LTL formulas over a set of atoms comprising bounded MTL formu ..."
Abstract
 Add to MetaCart
(Show Context)
Abstract. Current approaches to monitoring realtime properties suffer either from unbounded space requirements or lack of expressiveness. In this paper, we adapt a separation technique enabling us to rewrite arbitrary MTL formulas into LTL formulas over a set of atoms comprising bounded MTL formulas. As a result, we obtain the first tracelength independent online monitoring procedure for full MTL. 1
Bounded Variability of Metric Temporal Logic
, 2013
"... Previous work has shown that reasoning with realtime temporal logics is often simpler when restricted to models with bounded variability—where no more than v events may occur every V time units, for given v, V. When reasoning about formulas with intrinsic bounded variability, one can employ the sim ..."
Abstract
 Add to MetaCart
(Show Context)
Previous work has shown that reasoning with realtime temporal logics is often simpler when restricted to models with bounded variability—where no more than v events may occur every V time units, for given v, V. When reasoning about formulas with intrinsic bounded variability, one can employ the simpler techniques that rely on bounded variability, without any loss of generality. What is then the complexity of algorithmically deciding which formulas have intrinsic bounded variability? In this paper, we study the problem with reference to Metric Temporal Logic (MTL). We prove that deciding bounded variability of MTL formulas is undecidable over densetime models, but with a undecidability degree lower than generic densetime MTL satisfiability. Over discretetime models, instead, deciding MTL bounded variability has the same exponentialspace complexity as satisfiability. To complement these negative results, we also discuss fragments of MTL that are more amenable to reasoning about bounded variability, again both for discrete and for densetime models. 1 The Benefits of Bounding Variability In yet another instance of the principle that “there ain’t no such thing as a free lunch”, expressiveness of formal languages comes with a significant cost to pay in terms of complexity—and possibly undecidability—of algorithmic analysis. The tradeoff between expressiveness and complexity is particularly critical for the realtime temporal logics, which dwell on the border of intractability. A chief research challenge is, therefore, identifying expressive temporal logic fragments without letting the “dark side ” of undecidability [6] prevail and abate practical usability.