Ambient seismic noise and microseismicity monitoring of a prone-to-fall quartzite tower (Ormea, NW Italy)

Remote sensing techniques are leading methodologies for landslide characterization and monitoring. However, they may be limited in highly vegetated areas and do not allow for continuously tracking the evolution to failure in an early warning perspective. Alternative or complementary methods should be designed for potentially unstable sites in these environments. The results of a six-month passive seismic monitoring experiment on a prone-to-fall quartzite tower are here pre-sented. Ambient seismic noise and microseismicity analyses were carried out on the continuously recorded seismic traces to characterize site stability and monitor its possible irreversible and reversible modifications driven by meteorological factors, in comparison with displacement measured on site. No irreversible modifications in the measured seismic parameters (i.e., natural resonance fre-quencies of the tower, seismic velocity changes, rupture-related microseismic signals) were detected in the monitored period, and no permanent displacement was observed at the tower top. Results highlighted, however, a strong temperature control on these parameters and unusual preferential vibration directions with respect to the literature case studies on nearly 2D rock columns, likely due the tower geometric constraints, as confirmed by 3D numerical modeling. A clear correlation with the tower displacement rate was found in the results, supporting the suitability of passive seismic monitoring systems for site characterization and early waning purposes

A procedure for splitting data-aware processes and its application to coordination

We present a procedure for splitting processes in a process algebra with multiactions and data (the untimed subset of the specification language mCRL2). This splitting procedure cuts a process into two processes along a set of actions A: Roughly, one of these processes contains no actions from A, while the other process contains only actions from A. We state and prove a theorem asserting that the parallel composition of these two processes is provably equal from a set of axioms (sound and complete with respect to strong bisimilarity) to the original process under some appropriate notion of synchronization. We apply our splitting procedure to the process algebraic semantics of the coordination language Reo: Using this procedure and its related theorem, we formally establish the soundness of splitting Reo connectors along the boundaries of their (a)synchronous regions in implementations of Reo

Multiscale seismic characterization and monitoring of a potentially unstable rock mass: the Madonna del Sasso (NW Italy) rockfall

Active (e.g. surface refraction and cross-hole tomography) and passive (monitoring of microseismic events) seismic methods can provide a proper characterization of the inner structure of the rock mass and are key to the comprehension of the mechanisms enhancing the instability of rock masses.We propose a multiscale approach for the characterization of the potentially unstable granitic cliff of Madonna del Sasso (NW Italian Alps) integrating prospecting surveys, laboratory tests, long-term microseismic monitoring and numerical modeling. The complex 3-D fracture setting, the geometry of the unstable sector was achieved through field observations, photogrammetric geomechanical analysis and interpretation of on-site seismic surveys, which revealed to be fundamental for constraining the fracture geometry and opening at depth within the rock mass. Physical and mechanical properties of the investigated medium were obtained through laboratory tests on granite samples. Continuous monitoring of ambient vibration at the site (October 2013 - present) did not highlight irreversible changes in the rock mass properties precursory to an acceleration to failure. However, a strong thermal control was found to govern the stability of the cliff, with reversible seasonal opening and closing of fractures resulting from thermal contraction and expansion. Moreover, the vibration modes of the unstable sector were found to be strongly controlled by the complex 3-D geometry of the main fracture planes affecting the site. Detection and location of microseismic events within the prone-to-fall rock mass highlighted the concentration of low energy releases close to the major fracture planes. Microseismic monitoring at the laboratory scale of deformation and rupture processes is expected to further highlight the relationships between energy release, seismic signatures and seismic sources. Finally, finite element modeling on the 3-D geometry allowed an experimental validation and interpretation

Distributed programming using role-parametric session types in go

This paper presents a framework for the static specification and safe programming of message passing protocols where the number and kinds of participants are dynamically instantiated. We develop the first theory of distributed multiparty session types (MPST) to support parameterised protocols with indexed rolesÐour framework statically infers the different kinds of participants induced by a protocol definition as role variants, and produces decoupled endpoint projections of the protocol onto each variant. This enables safe MPST-based programming of the parameterised endpoints in distributed settings: each endpoint can be implemented separately by different programmers, using different techniques (or languages). We prove the decidability of role variant inference and well-formedness checking, and the correctness of projection. We implement our theory as a toolchain for programming such role-parametric MPST protocols in Go. Our approach is to generate API families of lightweight, protocol- and variant-specific type wrappers for I/O. The APIs ensure a well-typed Go endpoint program (by native Go type checking) will perform only compliant I/O actions w.r.t. the source protocol. We leverage the abstractions of MPST to support the specification and implementation of Go applications involving multiple channels, possibly over mixed transports (e.g., Go channels, TCP), and channel passing via a unified programming interface. We evaluate the applicability and run-time performance of our generated APIs using microbenchmarks and real-world applications

Seismic noise parameters as indicators of reversible modifications in slope stability: a review

Continuous ambient seismic monitoring of potentially unstable sites is increasingly attracting the attention of researchers for precursor recognition and early warning purposes. Twelve cases of long-term continuous noise monitoring have been reported in the literature between 2012 and 2020. Only in a few cases rupture was achieved and irreversible drops in resonance frequency values or shear wave velocity extracted from noise recordings were documented. On the other hand, all monitored sites showed clear reversible fluctuations of the seismic parameters on a daily and seasonal scale due to changes in external weather conditions (air temperature and precipitation). A quantitative comparison of these reversible modifications is used to gain insight into the mechanisms driving the site seismic response. Six possible mechanisms were identified, including three temperature-driven mechanisms (temperature control on fracture opening/closing, superficial stress conditions and bulk rigidity), one precipitation-driven mechanism (water infiltration effect) and two mechanisms sensitive to both temperature and precipitation (ice formation and clay behavior). The reversible variations in seismic parameters under the meteorological constraints are synthesized and compared to the irreversible changes observed prior to failure in different geological conditions

Интерпретация святости в романе Габриэля Гарсиа Маркеса "Сто лет одиночества"

В статье даётся описание мифологемы "святость"в семантическом пространстве романа Маркеса, раскрываются особенности авторской интерпретации данной культурной универсалии.В статті подається опис міфологеми "святость" в семантичному просторі романа Маркеса, розглядаються особливості авторської інтерпретації данної культурної універсалії.The article deals with the author's representation of the Christian concept of holiness as it is impersonated in the personage of Remedios the Beauty