763 research outputs found
Efficiently Integrating Boolean Reasoning and Mathematical Solving
Many real-world problems require the ability of reasoning efficiently on formulae which are boolean combinations of boolean and unquantified mathematical propositions. This task requires a fruitful combination of efficient boolean reasoning and mathematical solving capabilities. SAT tools and mathematical reasoners are respectively very effective on one of these activities each, but not on both. In this paper we present a formal framework, a generalized algorithm and architecture for integrating boolean reasoners and mathematical solvers so that they can efficiently solve boolean combinations of boolean and unquantified mathematical propositions. We describe many techniques to optimize this integration, and highlight the main requirements for SAT tools and mathematicalsolvers to maximize the benefits of their integration
Geological Criteria for Evaluating Seismicity Revisited: Forty Years of Paleoseismic Investigations and the Natural Record of Past Earthquakes
The identification of individual past earthquakes and their characterization in time and space, as well as in magnitude, can be approached in many different ways with a large variety of methods and techniques, using a wide spectrum of objects and
features. We revise the stratigraphic and geomorphic evidence currently used in the study of paleoseismicity, after more than three decades since the work by Allen (1975),
which was arguably the first critical overview in the field of earthquake geology. Natural objects or geomarkers suitable for paleoseismic analyses are essentially preserved
in the sediments, and in a broader sense, in the geologic record. Therefore, the study of these features requires the involvement of geoscientists, but very frequently it is a
multidisciplinary effort. The constructed environment and heritage, which typically are the focus of archaeoseismology and macroseismology, here are left aside. The geomarkers
suitable to paleoseismic assessment can be grouped based on their physical relation to the earthquake\u2019s causative fault. If directly associated with the fault surface
rupture, these objects are known as direct or on-fault features (primary effects in the Environmental Seismic Intensity [ESI] 2007 scale). Conversely, those indicators not in direct contact with the fault plane are known as indirect or off-fault evidence
(secondary effects in the ESI 2007 scale). This second class of evidence can be subdivided into three types or subclasses: type A, which encompasses seismically induced effects, including soft-sediment deformation (soil liquefaction, mud diapirism), mass
movements (including slumps), broken (disturbed) speleothems, fallen precarious rocks, shattered basement rocks, and marks of degassing (pockmarks, mud volcanoes); type B, which consists of remobilized and redeposited sediments (turbidites, homogenites, and tsunamites) and transported rock fragments (erratic blocks); and type C, entailing regional markers of uplift or subsidence (such as reef tracts, microatolls, terrace risers, river channels, and in some cases progressive unconformities).
The first subclass of objects (type A) is generated by seismic shaking. The second subclass (type B) relates either to water bodies set in motion by the earthquake (for the sediments and erratic blocks) or to earthquake shaking; in a general way, they all relate to wave propagation through different materials. The third subclass (type C) is mostly related to the tectonic deformation itself and can range from local (next to the causative fault) to regional scale.
The natural exposure of the paleoseismic objects\u2014which necessarily conditions the paleoseismic approach employed\u2014is largely controlled by the geodynamic setting.
For instance, oceanic subduction zones are mostly submarine, while collisional settings tend to occur in continental environments. Divergent and wrenching margins may occur anywhere, in any marine, transitional, or continental environment.
Despite the fact that most past subduction earthquakes have to be assessed through indirect evidence, paleoseismic analyses of this category of events have made dramatic progress recently, owing to the increasingly catastrophic impact that they have on human society
Experimenting a Conflict-Driven Clause Learning Algorithm
International audienceExperimentation of new algorithms is the usual companion section of papers dealing with SAT. However, the behavior of those algorithms is so unpredictable that even strong experiments (hundreds of benchmarks, dozen of solvers) can be still misleading. We present here a set of experiments of very small changes of a canonical Conflict Driven Clause Learning (CDCL) solver and show that even very close versions can lead to very different behaviors. In some cases, the best of them could perfectly have been used to convince the reader of the efficiency of a new method for SAT. This observation can be explained by the lack of real experimental studies of CDCL solvers
Geological Criteria for Evaluating seismicity revisited: Forty Years of Paleoseismic Investigations and the Natural Record of Past Earthquakes
The identifi cation of individual past earthquakes and their characterization in
time and space, as well as in magnitude, can be approached in many different ways
with a large variety of methods and techniques, using a wide spectrum of objects and
features. We revise the stratigraphic and geomorphic evidence currently used in the
study of paleoseismicity, after more than three decades since the work by Allen (1975),
which was arguably the fi rst critical overview in the fi eld of earthquake geology. Natural
objects or geomarkers suitable for paleoseismic analyses are essentially preserved
in the sediments, and in a broader sense, in the geologic record. Therefore, the study
of these features requires the involvement of geoscientists, but very frequently it is a
multidisciplinary effort. The constructed environment and heritage, which typically
are the focus of archaeoseismology and macroseismology, here are left aside. The geomarkers
suitable to paleoseismic assessment can be grouped based on their physical
relation to the earthquake\u2019s causative fault. If directly associated with the fault surface
rupture, these objects are known as direct or on-fault features (primary effects
in the Environmental Seismic Intensity [ESI] 2007 scale). Conversely, those indicators
not in direct contact with the fault plane are known as indirect or off-fault evidence
(secondary effects in the ESI 2007 scale). This second class of evidence can be subdivided
into three types or subclasses: type A, which encompasses seismically induced
effects, including soft-sediment deformation (soil liquefaction, mud diapirism), mass
movements (including slumps), broken (disturbed) speleothems, fallen precarious
rocks, shattered basement rocks, and marks of degassing (pockmarks, mud volcanoes);
type B, which consists of remobilized and redeposited sediments (turbidites, homogenites, and tsunamites) and transported rock fragments (erratic blocks); and
type C, entailing regional markers of uplift or subsidence (such as reef tracts, microatolls,
terrace risers, river channels, and in some cases progressive unconformities).
The fi rst subclass of objects (type A) is generated by seismic shaking. The second
subclass (type B) relates either to water bodies set in motion by the earthquake (for
the sediments and erratic blocks) or to earthquake shaking; in a general way, they all
relate to wave propagation through different materials. The third subclass (type C) is
mostly related to the tectonic deformation itself and can range from local (next to the
causative fault) to regional scale.
The natural exposure of the paleoseismic objects\u2014which necessarily conditions
the paleoseismic approach employed\u2014is largely controlled by the geodynamic setting.
For instance, oceanic subduction zones are mostly submarine, while collisional
settings tend to occur in continental environments. Divergent and wrenching margins
may occur anywhere, in any marine, transitional, or continental environment.
Despite the fact that most past subduction earthquakes have to be assessed through
indirect evidence, paleoseismic analyses of this category of events have made dramatic
progress recently, owing to the increasingly catastrophic impact that they have
on human society
Future trends in paleoseismology: Integrated study of the seismic landscape as a vital tool in seismic hazard analyses
This paper forms the Introduction to this Special Issue of Tectonophysics, devoted to selected scientific research
presented during events sponsored by the INQUA Subcommission on Paleoseismicity in the past few years. In this
note, we summarize the contents of the contributed papers and use the issues they raise to review the state-of-the-art in
paleoseismology from a Quaternary geology perspective. In our opinion, the evolution of paleoseismological studies in
the past decade clearly demonstrates that in order to properly understand the seismic potential of a region, and to
assess the associated hazards, broad-based/multidisciplinary studies are necessary to take full advantage from the
geological evidence of past earthquakes. A major challenge in future paleoseismic research is to build detailed
empirical relations between various categories of coseismic effects in the natural environment and earthquake magnitude/
intensity. These relations should be compiled in a way that is fully representative of the wide variety of natural
environments on Earth, in terms of climatic settings, Quaternary tectonic evolution, rheological parameters of the
seismogenic crust, and stress environment. For instance, available data indicate that between earthquake magnitude and
surface faulting parameters different scaling laws exist, and they are a function of the local geodynamic setting
(including style of faulting, typical focal depths, heat flow). In this regard, we discuss in some detail the concept of
seismic landscape, which provides the necessary background for developing paleoseismological research strategies. The
large amount of paleoseismological data collected in recent years shows that each earthquake source creates a signature
on the geology and the geomorphology of an area that is unequivocally related with the order of magnitude of its
earthquake potential. This signature is defined as the seismic landscape of the area (e.g., Serva, L., Vittori, E., Ferreli,
L., Michetti, A.M., 1997. Geology and seismic hazard. In: Grellet, B., Mohammadioun, B., Hays, W. (Eds.),
Proceedings of the Second France\u2013United States Workshop on Earthquake Hazard Assessment in Intraplate Regions:
Central and Eastern United States and Western Europe, October 16, 1995, Nice, France, 20\u201324, Ouest Editions, Nantes,
France; Michetti, A.M., Hancock, P.L., 1997. Paleoseismology: understanding past earthquakes using quaternary geology Journal of Geodynamics 24 (1\u20134), 3\u201310). We then illustrate how this relatively new framework is helpful in understanding
the seismic behavior of faults capable of producing surface faulting and provides a comprehensive approach for the use of
paleoseismicity data in earthquake hazard characterization
Paleoseismology, integrated study of the Quaternary geological record for earthquake deformation and faulting
Tectonophysics 408 (2005) v\u2013 vi, Special Issue
Paleoseismology:
Integrated study of the Quaternary geological record
for earthquake deformation and faulting, doi:10.1016/S0040-1951(05)00465-
Proceedings of the 2022 XCSP3 Competition
This document represents the proceedings of the 2022 XCSP3 Competition. The
results of this competition of constraint solvers were presented at FLOC
(Federated Logic Conference) 2022 Olympic Games, held in Haifa, Israel from
31th July 2022 to 7th August, 2022.Comment: arXiv admin note: text overlap with arXiv:1901.0183
Exploitation des symétries dans les formules booléennes quantifiées
De nombreuses tâches et problèmes combinatoires exhibent des symétries. La résolution de tels problèmes conduit à répéter inlassablement l'étude de situations ou de sousproblèmes équivalents. Depuis plusieurs années, l'exploitation des symétries a permis une réduction significative de l'espace de recherche et la résolution de problèmes ouverts jusqu'alors. Ce paradigme important a été étudié de manière extensive dans de nombreux domaines, comme les problèmes de satisfaction de contraintes (CSP) ou la satisfiabilité de formules booléennes (SAT). L'approche consistant à rajouter des contraintes (symmetry breaking predicates en anglais) est l'une des techniques les plus utilisées pour casser les symétries. Après avoir montré pourquoi il est difficile d'étendre cette approche aux formules booléennes quantifiées, nous montrons comment générer une nouvelle formule équivalente à la formule de départ, mais ne contenant pas de symétries. L'évaluation expérimentale menée sur un des meilleurs solveurs QBF actuels montre des résultats très convaincants sur une grande variété d'instances QBF structurées
Automated Benchmarking of Incremental SAT and QBF Solvers
Incremental SAT and QBF solving potentially yields improvements when
sequences of related formulas are solved. An incremental application is usually
tailored towards some specific solver and decomposes a problem into incremental
solver calls. This hinders the independent comparison of different solvers,
particularly when the application program is not available. As a remedy, we
present an approach to automated benchmarking of incremental SAT and QBF
solvers. Given a collection of formulas in (Q)DIMACS format generated
incrementally by an application program, our approach automatically translates
the formulas into instructions to import and solve a formula by an incremental
SAT/QBF solver. The result of the translation is a program which replays the
incremental solver calls and thus allows to evaluate incremental solvers
independently from the application program. We illustrate our approach by
different hardware verification problems for SAT and QBF solvers.Comment: camera-ready version (8 pages + 2 pages appendix), to appear in the
proceedings of the 20th International Conference on Logic for Programming,
Artificial Intelligence and Reasoning (LPAR), LNCS, Springer, 201
XCSP3-core: A Format for Representing Constraint Satisfaction/Optimization Problems
In this document, we introduce XCSP3-core, a subset of XCSP3 that allows us
to represent constraint satisfaction/optimization problems. The interest of
XCSP3-core is multiple: (i) focusing on the most popular frameworks (CSP and
COP) and constraints, (ii) facilitating the parsing process by means of
dedicated XCSP3-core parsers written in Java and C++ (using callback
functions), (iii) and defining a core format for comparisons (competitions) of
constraint solvers.Comment: arXiv admin note: substantial text overlap with arXiv:1611.0339
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