133,798 research outputs found
A Metric for Linear Temporal Logic
We propose a measure and a metric on the sets of infinite traces generated by
a set of atomic propositions. To compute these quantities, we first map
properties to subsets of the real numbers and then take the Lebesgue measure of
the resulting sets. We analyze how this measure is computed for Linear Temporal
Logic (LTL) formulas. An implementation for computing the measure of bounded
LTL properties is provided and explained. This implementation leverages SAT
model counting and effects independence checks on subexpressions to compute the
measure and metric compositionally
Analytic Torsion of Z_2-graded Elliptic Complexes
We define analytic torsion of Z_2-graded elliptic complexes as an element in
the graded determinant line of the cohomology of the complex, generalizing most
of the variants of Ray-Singer analytic torsion in the literature. It applies to
a myriad of new examples, including flat superconnection complexes, twisted
analytic and twisted holomorphic torsions, etc. The definition uses
pseudo-differential operators and residue traces. We also study properties of
analytic torsion for Z_2-graded elliptic complexes, including the behavior
under variation of the metric. For compact odd dimensional manifolds, the
analytic torsion is independent of the metric, whereas for even dimensional
manifolds, a relative version of the analytic torsion is independent of the
metric. Finally, the relation to topological field theories is studied.Comment: 14 pages, typos corrected and other minor changes made in the revised
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An Efficient Algorithm for Monitoring Practical TPTL Specifications
We provide a dynamic programming algorithm for the monitoring of a fragment
of Timed Propositional Temporal Logic (TPTL) specifications. This fragment of
TPTL, which is more expressive than Metric Temporal Logic, is characterized by
independent time variables which enable the elicitation of complex real-time
requirements. For this fragment, we provide an efficient polynomial time
algorithm for off-line monitoring of finite traces. Finally, we provide
experimental results on a prototype implementation of our tool in order to
demonstrate the feasibility of using our tool in practical applications
On-Line Monitoring for Temporal Logic Robustness
In this paper, we provide a Dynamic Programming algorithm for on-line
monitoring of the state robustness of Metric Temporal Logic specifications with
past time operators. We compute the robustness of MTL with unbounded past and
bounded future temporal operators MTL over sampled traces of Cyber-Physical
Systems. We implemented our tool in Matlab as a Simulink block that can be used
in any Simulink model. We experimentally demonstrate that the overhead of the
MTL robustness monitoring is acceptable for certain classes of practical
specifications
Tensor-Based Link Prediction in Intermittently Connected Wireless Networks
Through several studies, it has been highlighted that mobility patterns in
mobile networks are driven by human behaviors. This effect has been
particularly observed in intermittently connected networks like DTN (Delay
Tolerant Networks). Given that common social intentions generate similar human
behavior, it is relevant to exploit this knowledge in the network protocols
design, e.g. to identify the closeness degree between two nodes. In this paper,
we propose a temporal link prediction technique for DTN which quantifies the
behavior similarity between each pair of nodes and makes use of it to predict
future links. Our prediction method keeps track of the spatio-temporal aspects
of nodes behaviors organized as a third-order tensor that aims to records the
evolution of the network topology. After collapsing the tensor information, we
compute the degree of similarity for each pair of nodes using the Katz measure.
This metric gives us an indication on the link occurrence between two nodes
relying on their closeness. We show the efficiency of this method by applying
it on three mobility traces: two real traces and one synthetic trace. Through
several simulations, we demonstrate the effectiveness of the technique
regarding another approach based on a similarity metric used in DTN. The
validity of this method is proven when the computation of score is made in a
distributed way (i.e. with local information). We attest that the tensor-based
technique is effective for temporal link prediction applied to the
intermittently connected networks. Furthermore, we think that this technique
can go beyond the realm of DTN and we believe this can be further applied on
every case of figure in which there is a need to derive the underlying social
structure of a network of mobile users.Comment: 13 pages, 9 figures, 8 tables, submitted to the International Journal
of Computer and Telecommunications Networking (COMNET
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