Archivio della ricerca - Fondazione Bruno Kessler
Causality and Temporal Dependencies in the Design of Fault Management Systems
Reasoning about causes and effects naturally arises in the engineering of safety-critical systems. A classical example is Fault Tree Analysis, a deductive technique used for system safety assessment, whereby an undesired state is reduced to the set of its immediate causes. The design of fault management systems also requires reasoning on causality relationships. In particular, a fail-operational system needs to ensure timely detection and identification of faults, i.e. recognize the occurrence of run-time faults through their observable effects on the system. Even more complex scenarios arise when multiple faults are involved and may interact in subtle ways.
In this work, we propose a formal approach to fault management for complex systems. We first introduce the notions of fault tree and minimal cut sets. We then present a formal framework for the specification and analysis of diagnosability, and for the design of fault detection and identification (FDI) components. Finally, we review recent advances in fault propagation analysis, based on the Timed Failure Propagation Graphs (TFPG) formalism
PINCH: Self-Organized Context Neighborhoods for Smart Environments
Today’s “smart” domains are driven by lightweight battery operated devices carried by people and embedded in environments. Many applications rely on con- tinuous neighbor discovery, i.e., the ability to detect other nearby devices. Application uses for neighbor discovery are widely varying, but they all rely on a protocol in which devices exchange periodic beacons containing device identi- fiers. Many applications also ultimately involve assessing and adapting to context information sensed about the physical world and the device’s situation in that world (e.g., its location or speed, the ambient temperature or sound, etc.). In this paper, we define Proactive Implicit Neighborhood Context Heuristics (PINCH), which leverages unused payload in periodic neighbor discovery beacons to opportunistically distribute context information in a local area. PINCH’s self- organizing algorithms use limited local views of the state of a one-hop network neighborhood to determine the most useful type of context information for a device to sense and share. In this paper, we develop the algorithms, integrate an implementation of PINCH with a smart city simulator, and benchmark the tradeoffs of self-organized local context sharing with 2.4GHz neighbor discovery beacons
Compliance in Business Processes with Incomplete Information and Time Constraints: a General Framework based on Abductive Reasoning
The capability to store data about Business Process (BP) executions in so-called Event Logs has brought to the identification of a range of key reasoning services (consistency, compliance, runtime monitoring, prediction) for the analysis of process executions and process models. Tools for the provision of these services typically focus on one form of reasoning alone. Moreover, they are often very rigid in dealing with forms of incomplete information about the process execution. While this enables the development of ad hoc solutions, it also poses an obstacle for the adoption of reasoning-based solutions in the BP community. In this paper, we introduce the notion of Structured Processes with Observability and Time (SPOT models), able to support incompleteness (of traces and logs), and temporal constraints on the activity duration and between activities. Then, we exploit the power of abduction to provide a flexible, yet computationally effective framework able to reinterpret key reasoning services in terms of incompleteness and observability in a uniform way
Neural Machine Translation into Language Varieties
Both research and commercial machine trans- lation have so far neglected the importance of properly handling the spelling, lexical and grammar divergences occurring among lan- guage varieties. Notable cases are standard national varieties such as Brazilian and Euro- pean Portuguese, and Canadian and European French, which popular online machine transla- tion services are not keeping distinct. We show that an evident side effect of modeling such va- rieties as unique classes is the generation of inconsistent translations. In this work, we in- vestigate the problem of training neural ma- chine translation from English to specific pairs of language varieties, assuming both labeled and unlabeled parallel texts, and low-resource conditions. We report experiments from En- glish to two pairs of dialects, European- Brazilian Portuguese and European-Canadian French, and two pairs of standardized vari- eties, Croatian-Serbian and Indonesian-Malay. We show significant BLEU score improve- ments over baseline systems when translation into similar languages is learned as a multilin- gual task with shared representations
Constraining Cycle Alternations in Model Checking for Interval Temporal Logic
Model checking is one of the most successful techniques in system verification. While a variety of methods and tools exist to check properties expressed in point-based temporal logics, like LTL and CTL, model checking for interval temporal logic has entered the research agenda only very recently. In previous work, we devised a non-elementary model checking procedure for Halpern and Shoham's modal logic of time intervals, interpreted over finite Kripke structures, and an EXPSPACE algorithm for two meaningful fragments of it. In this paper, we show that the latter algorithm can be suitably tailored in order to check a subset of the computations of a system, that satisfy a given bound on the number of cycle alternations, by making use of a polynomial (instead of exponential) working space. We also prove that such a revised algorithm turns out to be complete for Kripke structures whose strongly connected components are simple cycles
Tracking the sociomaterial traces of affect at the crossroads of affect and practice theories
The authors wish to express gratitude to Angelo Benozzo who supported the authors’ writing process with his friendship and encouragement. The authors would like to thank also the anonymous reviewers for their insightful comments. Naturally they are not responsible for the particular form that the arguments take here. This paper is a collaborative effort by the five authors, nevertheless if for academic reasons individual authorship has to be attributed, Silvia Gherardi wrote the sections “The encounter between the turn to practice and the turn to affect,” “The in-between-ness of bodies and trans-corporeality,” and the “Conclusion”; Annalisa Murgia wrote the sections “Second Episode: the transformative power of affect,” and the “Discussion”; Elisa Bellè wrote the section “First episode: resonance of boundaryless bodies”; Anna Carreri wrote the “Introduction,” and Francesco Miele wrote the section “Affect and empirical research: a methodological note.
Social innovation in dynamic environments: organising technology for temporary advantage
A new challenge for public-private partnerships lies in gaining temporary advantage through social innovation, in order to operate within
dynamic environments. This research explores social innovation enabled by technology, in order to build an empirical model that can be useful in addressing social needs of the citizens, while increasing temporary advantages for the companies. This research presents an entrepreneurial approach in which public-private partnerships can organise technology in order to develop and diffuse social innovation within dynamic environments. By employing this model, citizens can be empowered to participate in the joint construction of social innovation enabled by information and communication technology, in particular the phenomenon of shared data. The social entrepreneurship approach enables public-private partnerships to leverage shared data and obtain temporary advantages. This aids in developing innovative solutions to improve quality of life of citizens while it enables companies to succeed in dynamic environments
A SiPM-Based Detection Module for 2” LaBr3:Ce Readout for Nuclear Physics Applications
We present a SiPM-based gamma-ray detection
module, which allows to read large LaBr3:Ce cylindrical crystals
(diameter > 1”), typically adopted in nuclear physics
experiments, with spectroscopic performances similar to those
achievable with PMTs. High-Density SiPM technology for Near
UltraViolet and blue light detection (NUV-HD, Fondazione
Bruno Kessler, Italy) were used. These SiPMs show high Photo
Detection Efficiency (PDE = 45% at 380 nm) and low Dark
Count Rate (DCR < 100 kHz/mm2). The photodetector prototype
has a modular structure based on an array of 5 × 6 SiPMs, each
one having an active area of 6 × 6 mm2 and 30 μm microcells.
This array was used for 1” scintillator readout and it was
assembled in 2 × 2 planar format for the 2” scintillator readout.
The spectroscopic measurements presented in this work were
performed with 2” × 2” LaBr3:Ce irradiated with 57-Co, 133-Ba,
137-Cs and 60-Co calibration sources. An energy resolution of 3.19 ±
0.01% was achieved at 662 keV with 2” LaBr3:Ce. The same
crystal was tested with a Super Bialkali PMT (Hamamatsu
R6233-100) showing a similar energy resolution of 3.07 ± 0.03%
at 662 keV. Therefore, these results support the equivalence
between SiPM and PMT for high-resolution spectroscopy
INSERT: A Novel Clinical Scanner for Simultaneous SPECT/MRI Brain Studies
A clinical SPECT insert for a commercial MRI scanner has been developed within the INSERT project, allowing simultaneous SPECT/MRI studies of the human brain. Here we present preliminary experimental results. The reconstructed resolution was 6-11 mm and the sensitivity 280-440 s^-1/MBq. The INSERT is the first clinical SPECT prototype for simultaneous SPECT/MRI
XRF topography information: Simulations and data from a novel silicon drift detector system
This work presents the latest findings of an ongoing research project where the angular dependence of XRF detection could be exploited for the topographical study of the specimen. It presents the results of a simulation framework and of measurements performed with a new detector system deployed on the TwinMic beamline (Elettra Sincrotrone Trieste, Trieste, Italy)