22,790 research outputs found
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
Robust Online Monitoring of Signal Temporal Logic
Signal Temporal Logic (STL) is a formalism used to rigorously specify
requirements of cyberphysical systems (CPS), i.e., systems mixing digital or
discrete components in interaction with a continuous environment or analog com-
ponents. STL is naturally equipped with a quantitative semantics which can be
used for various purposes: from assessing the robustness of a specification to
guiding searches over the input and parameter space with the goal of falsifying
the given property over system behaviors. Algorithms have been proposed and
implemented for offline computation of such quantitative semantics, but only
few methods exist for an online setting, where one would want to monitor the
satisfaction of a formula during simulation. In this paper, we formalize a
semantics for robust online monitoring of partial traces, i.e., traces for
which there might not be enough data to decide the Boolean satisfaction (and to
compute its quantitative counterpart). We propose an efficient algorithm to
compute it and demonstrate its usage on two large scale real-world case studies
coming from the automotive domain and from CPS education in a Massively Open
Online Course (MOOC) setting. We show that savings in computationally expensive
simulations far outweigh any overheads incurred by an online approach
Efficient Monitoring of Parametric Context Free Patterns
Recent developments in runtime verification and monitoring show that parametric regular and temporal logic specifications can be efficiently monitored against large programs. However, these logics reduce to ordinary finite automata, limiting their expressivity. For example, neither can specify structured properties that refer to the call stack of the program. While context-free grammars (CFGs) are expressive and well-understood, existing techniques of monitoring CFGs generate massive runtime overhead in real-life applications. This paper shows for the first time that monitoring parametric CFGs is practical (on the order of 10% or lower for average cases, several times faster than the state-of-the-art). We present a monitor synthesis algorithm for CFGs based on an LR(1) parsing algorithm, modified with stack cloning to account for good prefix matching. In addition, a logic-independent mechanism is introduced to support partial matching, allowing patterns to be checked against fragments of execution traces
A Lightweight, Non-intrusive Approach for Orchestrating Autonomously-managed Network Elements
Software-Defined Networking enables the centralized orchestration of data
traffic within a network. However, proposed solutions require a high degree of
architectural penetration. The present study targets the orchestration of
network elements that do not wish to yield much of their internal operations to
an external controller. Backpressure routing principles are used for deriving
flow routing rules that optimally stabilize a network, while maximizing its
throughput. The elements can then accept in full, partially or reject the
proposed routing rule-set. The proposed scheme requires minimal, relatively
infrequent interaction with a controller, limiting its imposed workload,
promoting scalability. The proposed scheme exhibits attracting network
performance gains, as demonstrated by extensive simulations and proven via
mathematical analysis.Comment: 6 pages 7, figures, IEEE ISCC'1
Avoiding core's DUE & SDC via acoustic wave detectors and tailored error containment and recovery
The trend of downsizing transistors and operating voltage scaling has made the processor chip more sensitive against radiation phenomena making soft errors an important challenge. New reliability techniques for handling soft errors in the logic and memories that allow meeting the desired failures-in-time (FIT) target are key to keep harnessing the benefits of Moore's law. The failure to scale the soft error rate caused by particle strikes, may soon limit the total number of cores that one may have running at the same time. This paper proposes a light-weight and scalable architecture to eliminate silent data corruption errors (SDC) and detected unrecoverable errors (DUE) of a core. The architecture uses acoustic wave detectors for error detection. We propose to recover by confining the errors in the cache hierarchy, allowing us to deal with the relatively long detection latencies. Our results show that the proposed mechanism protects the whole core (logic, latches and memory arrays) incurring performance overhead as low as 0.60%. © 2014 IEEE.Peer ReviewedPostprint (author's final draft
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