Event ordering through temporal expression resolution

In this paper a multilingual method for event ordering based on temporal expression resolution is presented. This method has been implemented through the TERSEO system which consists of three main units: temporal expression recognizing, resolution of the coreference introduced by these expressions, and event ordering. By means of this system, chronological information related to events can be extracted from documental databases. This information is automatically added to the documental database in order to allow its use by question answering systems in those cases referring to temporality. The system has been evaluated obtaining results of 91 % precision and 71 % recall. For this, a blind evaluation process has been developed guaranteing a reliable annotation process that was measured through the kappa factor.

Parametric & nonparametric approaches to event studies: an application to a hotel’s market value

The main objective of this paper is twofold: on the one hand, to analyse the impact that the announcement of the opening of a new hotel has on the performance of its chain by carrying out an event study, and on the other hand, to compare the results of two different approaches to this method: a parametric specification based on the autoregressive conditional heteroskedasticity models to estimate the market model, and a nonparametric approach, which implies employing Theil’s nonparametric regression technique, which in turn, leads to the so-called complete nonparametric approach to event studies. The results that the empirical application arrives at are noteworthy as, on average, the reaction to such news releases is highly positive, both approaches reaching the same level of significance. However, a word of caution must be said when one is not only interested in detecting whether the market reacts, but also in obtaining an exhaustive calculation of the abnormal returns to further examine its determining factors.

Event-based visual servoing

Traditional visual servoing systems have been widely studied in the last years. These systems control the position of the camera attached to the robot end-effector guiding it from any position to the desired one. These controllers can be improved by using the event-based control paradigm. The system proposed in this paper is based on the idea of activating the visual controller only when something significant has occurred in the system (e.g. when any visual feature can be loosen because it is going outside the frame). Different event triggers have been defined in the image space in order to activate or deactivate the visual controller. The tests implemented to validate the proposal have proved that this new scheme avoids visual features to go out of the image whereas the system complexity is reduced considerably. Events can be used in the future to change different parameters of the visual servoing systems.

Event-based visual servoing with features’ prediction

Event-based visual servoing is a recently presented approach that performs the positioning of a robot using visual information only when it is required. From the basis of the classical image-based visual servoing control law, the scheme proposed in this paper can reduce the processing time at each loop iteration in some specific conditions. The proposed control method enters in action when an event deactivates the classical image-based controller (i.e. when there is no image available to perform the tracking of the visual features). A virtual camera is then moved through a straight line path towards the desired position. The virtual path used to guide the robot improves the behavior of the previous event-based visual servoing proposal.

Evolution of the last koninckinids (Athyridida, Koninckinidae), a precursor signal of the early Toarcian mass extinction event in the Western Tethys

Koninckinids are a suitable group to shed light on the biotic crisis suffered by brachiopod fauna in the Early Jurassic. Koninckinid fauna recorded in the late Pliensbachian–early Toarcian from the easternmost Subbetic basin is analyzed and identified as a precursor signal for one of the most conspicuous mass extinction events of the Phylum Brachiopoda, a multi-phased interval with episodes of changing environmental conditions, whose onset can be detected from the Elisa–Mirabile subzones up to the early Toarcian extinction boundary in the lowermost Serpentinum Zone (T-OAE). The koninckinid fauna had a previously well-established migration pattern from the intra-Tethyan to the NW-European basins but a first phase with a progressive warming episode in the Pliensbachian–Toarcian transition triggered a koninckinid fauna exodus from the eastern/central Tethys toward the westernmost Mediterranean margins. A second stage shows an adaptive response to more adverse conditions in the westernmost Tethyan margins and finally, an escape and extinction phase is detected in the Atlantic areas from the mid-Polymorphum Zone onwards up to their global extinction in the lowermost Serpentinum Zone. This migration pattern is independent of the paleogeographic bioprovinciality and is unrelated to a facies-controlled pattern. The anoxic/suboxic environmental conditions should only be considered as a minor factor of partial control since well-oxygenated habitats are noted in the intra-Tethyan basins and this factor is noticeable only in the second westward migratory stage (with dwarf taxa and oligotypical assemblages). The analysis of cold-seep proxies in the Subbetic deposits suggests a radiation that is independent of methane releases in the Subbetic basin.

Seismically-induced landslides by a low-magnitude earthquake: The Mw 4.7 Ossa De Montiel event (central Spain)

The Ossa de Montiel (2015/02/23, Mw 4.7) earthquake struck the central part of Spain and was felt far from the epicenter (> 300 km). Even though ground shaking was slight (Imax = V, EMS-98 scale), the earthquake triggered many small rock falls, most at distances of 20–30 km from the epicenter, greater than previously recorded in S Spain (16 km) for earthquakes of similar magnitudes. The comparative analysis of available data for this event with records from other quakes of the Betic cordillera (S and SE Spain) seems to indicate a slower pattern of ground-motion attenuation in central Spain. This could explain why slope instabilities occurred at larger distances. Instability was more frequent, and occurred at larger distances, in road cuts than in natural slopes, implying that such slope types are highly susceptible to seismically induced landslides.

The Early Miocene “Bisciaro volcaniclastic event” (northern Apennines, Italy): a key study for the geodynamic evolution of the central-western Mediterranean

The Early Miocene Bisciaro Fm., a marly limestone succession cropping out widely in the Umbria–Romagna–Marche Apennines, is characterized by a high amount of volcaniclastic content, characterizing this unit as a peculiar event of the Adria Plate margin. Because of this volcaniclastic event, also recognizable in different sectors of the central-western Mediterranean chains, this formation is proposed as a “marker” for the geodynamic evolution of the area. In the Bisciaro Fm., the volcaniclastic supply starts with the “Raffaello” bed (Earliest Aquitanian) that marks the base of the formation and ends in the lower portion of the Schlier Fm. (Late Burdigalian–Langhian p.p.). Forty-one studied successions allowed the recognition of three main petrofacies: (1) Pyroclastic Deposits (volcanic materials more than 90 %) including the sub-petrofacies 1A, Vitroclastic/crystallo-vitroclastic tuffs; 1B, Bentonitic deposits; and 1C, Ocraceous and blackish layers; (2) Resedimented Syn-Eruptive Volcanogenic Deposits (volcanic material 30–90 %) including the sub-petrofacies 2A, High-density volcanogenic turbidites; 2B, Low-density volcanogenic turbidites; 2C, Crystal-rich volcanogenic deposits; and 2D, Glauconitic-rich volcaniclastites; (3) Mixing of Volcaniclastic Sediments with Marine Deposits (volcanic material 5–30 %, mixed with marine sediments: marls, calcareous marls, and marly limestones). Coeval volcaniclastic deposits recognizable in different tectonic units of the Apennines, Maghrebian, and Betic Chains show petrofacies and chemical–geochemical features related to a similar calc-alkaline magmatism. The characterization of this event led to the hypothesis of a co-genetic relationship between volcanic activity centres (primary volcanic systems) and depositional basins (depositional processes) in the Early Miocene palaeogeographic and palaeotectonic evolution of the central-western Mediterranean region. The results support the proposal of a geodynamic model of this area that considers previously proposed interpretations.