281 research outputs found
A Comprehensive Python Library for Deep Learning-Based Event Detection in Multivariate Time Series Data and Information Retrieval in NLP
Event detection in time series data is crucial in various domains, including
finance, healthcare, cybersecurity, and science. Accurately identifying events
in time series data is vital for making informed decisions, detecting
anomalies, and predicting future trends. Despite extensive research exploring
diverse methods for event detection in time series, with deep learning
approaches being among the most advanced, there is still room for improvement
and innovation in this field. In this paper, we present a new deep learning
supervised method for detecting events in multivariate time series data. Our
method combines four distinct novelties compared to existing deep-learning
supervised methods. Firstly, it is based on regression instead of binary
classification. Secondly, it does not require labeled datasets where each point
is labeled; instead, it only requires reference events defined as time points
or intervals of time. Thirdly, it is designed to be robust by using a stacked
ensemble learning meta-model that combines deep learning models, ranging from
classic feed-forward neural networks (FFNs) to state-of-the-art architectures
like transformers. This ensemble approach can mitigate individual model
weaknesses and biases, resulting in more robust predictions. Finally, to
facilitate practical implementation, we have developed a Python package to
accompany our proposed method. The package, called eventdetector-ts, can be
installed through the Python Package Index (PyPI). In this paper, we present
our method and provide a comprehensive guide on the usage of the package. We
showcase its versatility and effectiveness through different real-world use
cases from natural language processing (NLP) to financial security domains.Comment: 2023 International Conference on Machine Learning and Applications
(ICMLA
Counterterrorism in Belgium: Key challenges and policy options. Egmont Paper 89, October 2016
From the Introduction. Some days can never be forgotten. Tuesday, 22 March, started just like any other day
of any other week, as another grey morning followed another cold night in Belgium.
But at exactly 7:58, that morning turned into a living nightmare. Two individuals
detonated powerful bombs in the departure hallway of Brussels Airport. One hour
later, at 9:11 a.m., a third explosion in the Brussels subway confirmed that Belgium
was under attack. Thirty-two people died, and more than 300 were injured on that
tragic day. For most Belgian citizens and residents, this was more than a tragedy; it
was a traumatic event. Many could relate with the victims or with the location of the
attacks. Most people still recall exactly where they were, and what they were doing
at the moment they heard the news
Modeling the growth of stylolites in sedimentary rocks
[1] Stylolites are ubiquitous pressure solution seams found in sedimentary rocks. Their morphology is shown to follow two self-affine regimes. Analyzing the scaling properties of their height over their average direction shows that (1) at small scale, they are self-affine surfaces with a Hurst exponent around 1, and (2) at large scale, they follow another self-affine scaling with Hurst exponent around 0.5. In the present paper, we show theoretically the influence of the main principal stress and the local geometry of the stylolitic interface on the dissolution reaction rate. We compute how it is affected by the deviation between the principal stress axis and the local interface between the rock and the soft material in the stylolite. The free energy entering in the dissolution reaction kinetics is expressed from the surface energy term and via integration from the stress perturbations due to these local misalignments. The resulting model shows the interface evolution at different stress conditions. In the stylolitic case, i.e., when the main principal stress is normal to the interface, two different stabilizing terms dominate at small and large scales which are linked respectively to the surface energy and to the elastic interactions. Integrating the presence of small-scale heterogeneities related to the rock properties of the grains in the model leads to the formulation of a Langevin equation predicting the dynamic evolution of the surface. This equation leads to saturated surfaces obeying the two observed scaling laws. Analytical and numerical analysis of this surface evolution model shows that the crossover length separating both scaling regimes depends directly on the applied far-field stress magnitude. This method gives the basis for the development of a paleostress magnitude marker. We apply the computation of this marker, i.e., the morphological analysis, on a stylolite found in the Dogger limestone layer located in the neighborhood of the ANDRA Underground Research Laboratory at Bure (eastern France). The results are consistent with the two scaling regimes expected, and the practical determination of the major principal paleostress, from the estimation of a crossover length, is illustrated on this example
Unique and Overlapping Symptoms in Schizophrenia Spectrum and Dissociative Disorders in Relation to Models of Psychopathology:A Systematic Review
Schizophrenia spectrum disorders (SSDs) and dissociative disorders (DDs) are described in the fifth edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) and tenth edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) as 2 categorically distinct diagnostic categories. However, several studies indicate high levels of co-occurrence between these diagnostic groups, which might be explained by overlapping symptoms. The aim of this systematic review is to provide a comprehensive overview of the research concerning overlap and differences in symptoms between schizophrenia spectrum and DDs. For this purpose the PubMed, PsycINFO, and Web of Science databases were searched for relevant literature. The literature contained a large body of evidence showing the presence of symptoms of dissociation in SSDs. Although there are quantitative differences between diagnoses, overlapping symptoms are not limited to certain domains of dissociation, nor to nonpathological forms of dissociation. In addition, dissociation seems to be related to a history of trauma in SSDs, as is also seen in DDs. There is also evidence showing that positive and negative symptoms typically associated with schizophrenia may be present in DD. Implications of these results are discussed with regard to different models of psychopathology and clinical practice
Parasitic Nematodes Exert Antimicrobial Activity and Benefit From Microbiota-Driven Support for Host Immune Regulation
Intestinal parasitic nematodes live in intimate contact with the host microbiota. Changes in the microbiome composition during nematode infection affect immune control of the parasites and shifts in the abundance of bacterial groups have been linked to the immunoregulatory potential of nematodes. Here we asked if the small intestinal parasite Heligmosomoides polygyrus produces factors with antimicrobial activity, senses its microbial environment and if the anti-nematode immune and regulatory responses are altered in mice devoid of gut microbes. We found that H. polygyrus excretory/secretory products exhibited antimicrobial activity against gram+/− bacteria. Parasites from germ-free mice displayed alterations in gene expression, comprising factors with putative antimicrobial functions such as chitinase and lysozyme. Infected germ-free mice developed increased small intestinal Th2 responses coinciding with a reduction in local Foxp3+RORγt+ regulatory T cells and decreased parasite fecundity. Our data suggest that nematodes sense their microbial surrounding and have evolved factors that limit the outgrowth of certain microbes. Moreover, the parasites benefit from microbiota-driven immune regulatory circuits, as an increased ratio of intestinal Th2 effector to regulatory T cells coincides with reduced parasite fitness in germ-free mice.Peer Reviewe
: A new Late Upper Palaeolithic site in southwestern France: Le Petit Cloup Barrat (Cabrerets, Lot)
International audienceDer Fundort Le Petit Cloup Barrat öffnet sich zum Rande einer kleinen Doline hin, in 800 m Entfernung vom Eingang der berühmten Bilderhöhle von Pech Merle. Bei den seit 2003 laufenden Ausgrabungen wurden zahlreiche lithische und organische Siedlungsreste zu Tage gefördert, die dem mittleren und frühen Magdalénien, dem Badegoulien und dem Solutréen zugeordnet werden können. Die ältesten Schichten der Stratigraphie sind noch zu ergraben.The site of Le Petit Cloup Barrat opens on the edge of a small doline, 800 meters from the entrance of the famous decorated cave, Pech Merle. Though partially excavated at the beginning of the 20th century, this site has never been published. A test pit was opened in 2003, followed by excavations since 2004. The stratigraphic sequence, the base of which is still unknown, has yielded abundant lithic and organic remains attributed to the Middle and Lower Magdalenian, Badegoulian and Solutrean. In the upper ensemble attributed to the Magdalenian, numerous flint blade tools (end scrapers, burins, borers and retouched blades) coexist with backed bladelets. The Badegoulian is identified based on flake tools, including raclettes and transverse burins. An original industry, characterized by the production of twisted bladelets backed on the right side made from carinate cores, can be attributed to a Lower Magdalenian distinct from the Badegoulian. Finally, the Solutrean, still little excavated, is characterised by fragmented shouldered points and one fragment of a willow leaf point. The organic industry includes eyed needles, retouchers on medium-sized ungulate diaphyses and antler projectile points. The body ornaments consist of grooved and/or pierced shells, especially Dentalium, and herbivore incisors (reindeer, ibex). A few fossils, some with distant origins, were also recovered. Archaeozoological analysis shows a strong presence of reindeer, while horse is also present in various levels. The osseous material preserved in the cave will allow precise analyses of the seasons of occupation, hunting strategies, and alimentary and technical priorities
In-plane magnetic domains and N\'eel-like domain walls in thin flakes of the room temperature CrTe van der Waals ferromagnet
The recent discovery of magnetic van der Waals materials has triggered a
wealth of investigations in materials science, and now offers genuinely new
prospects for both fundamental and applied research. Although the catalogue of
van der Waals ferromagnets is rapidly expanding, most of them have a Curie
temperature below 300 K, a notable disadvantage for potential applications.
Combining element-selective x-ray magnetic imaging and magnetic force
microscopy, we resolve at room temperature the magnetic domains and domains
walls in micron-sized flakes of the CrTe van der Waals ferromagnet.
Flux-closure magnetic patterns suggesting in-plane six-fold symmetry are
observed. Upon annealing the material above its Curie point (315 K), the
magnetic domains disappear. By cooling back down the sample, a different
magnetic domain distribution is obtained, indicating material stability and
lack of magnetic memory upon thermal cycling. The domain walls presumably have
N\'eel texture, are preferentially oriented along directions separated by 120
degrees, and have a width of several tens of nanometers. Besides microscopic
mapping of magnetic domains and domain walls, the coercivity of the material is
found to be of a few mT only, showing that the CrTe compound is
magnetically soft. The coercivity is found to increase as the volume of the
material decreases
Enhancement of Antiferromagnetic Correlations Induced by Nonmagnetic Impurities: Origin and Predictions for NMR Experiments
Spin models that have been proposed to describe dimerized chains, ladders,
two dimensional antiferromagnets, and other compounds are here studied when
some spins are replaced by spinless vacancies, such as it occurs by
doping. A small percentage of vacancies rapidly destroys the spin gap, and
their presence induces enhanced antiferromagnetic correlations near those
vacancies. The study is performed with computational techniques which includes
Lanczos, world-line Monte Carlo, and the Density Matrix Renormalization Group
methods. Since the phenomenon of enhanced antiferromagnetism is found to occur
in several models and cluster geometries, a common simple explanation for its
presence may exist. It is argued that the resonating-valence-bond character of
the spin correlations at short distances of a large variety of models is
responsible for the presence of robust staggered spin correlations near
vacancies and lattice edges. The phenomenon takes place regardless of the long
distance properties of the ground state, and it is caused by a ``pruning'' of
the available spin singlets in the vicinity of the vacancies. The effect
produces a broadening of the low temperature NMR signal for the compounds
analyzed here. This broadening should be experimentally observable in the
structurally dimerized chain systems
, , , and
, in ladder materials such as , in the
spin-Peierls systems and , and in several others since it
is a universal effect common to a wide variety of models and compounds.Comment: 18 pages revtex with 26 figures include
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