346 research outputs found
A new computational method based on the minimum lithostatic deviation (MLD) principle to analyse slope stability in the frame of the 2-D limit-equilibrium theory
No full textThe stability of a slope is studied by applying the principle of the minimum lithostatic deviation (MLD) to the limit-equilibrium method, that was introduced in a previous paper (Tinti and Manucci, 2006; hereafter quoted as TM2006). The principle states that the factor of safety <i>F</i> of a slope is the value that minimises the lithostatic deviation, that is defined as the ratio of the average inter-slice force to the average weight of the slice. In this paper we continue the work of TM2006 and propose a new computational method to solve the problem. The basic equations of equilibrium for a 2-D vertical cross section of the mass are deduced and then discretised, which results in cutting the cross section into vertical slices. The unknowns of the problem are functions (or vectors in the discrete system) associated with the internal forces acting on the slice, namely the horizontal force <i>E</i> and the vertical force <i>X</i>, with the internal torque <i>A</i> and with the pressure on the bottom surface of the slide <i>P</i>. All traditional limit-equilibrium methods make very constraining assumptions on the shape of <i>X</i> with the goal to find only one solution. In the light of the MLD, the strategy is wrong since it can be said that they find only one point in the searching space, which could provide a bad approximation to the MLD. The computational method we propose in the paper transforms the problem into a set of linear algebraic equations, that are in the form of a block matrix acting on a block vector, a form that is quite suitable to introduce constraints on the shape of <i>X</i>, but also alternatively on the shape of <i>E</i> or on the shape of <i>X</i>. We test the new formulation by applying it to the same cases treated in TM2006 where <i>X</i> was expanded in a three-term sine series. Further, we make different assumptions by taking a three-term cosine expansion corrected by the local weight for <i>X</i>, or for <i>E</i> or for <i>A</i>, and find the corresponding MLDs. In the illustrative applications given in this paper, we find that the safety factors associated with the MLD resulting from our computations may differ by some percent from the ones computed with the traditional limit-equilibrium methods
Self-induced deformation on the fault plane during an earthquake part I: Continuous normal displacements
No full textThe problem of the coseismic deformation induced by an earthquake on its own fault plane is investigated here. The analysis concentrates on the on-fault displacement field accompanying the occurrence of an earthquake in response to a prescribed uniform shear slip and it is carried out on the basis of the classical analytical model by OKADA (1992) for a rectangular fault buried in an elastic homogeneous half-space delimited by a planar free surface. The analysis is subdivided into two separate papers: the first dealing with normal and the second with tangential on-fault displacements. In this first paper, concerning the study of the normal displacement component, the contributions of the source and of the correction introduced by the free surface are investigated separately and their dependence on the fault characteristics is thoroughly discussed. Particular attention is also devoted to the effects of the normal displacement on the fault surface geometry. It will be shown that the main effect is that of deforming the fault itself, with deformation consisting chiefly in a rotation of the plane and in a bending of the fault edges. The rotation angle is negligibly small (on the order of 1-10 μrad) for a single earthquake, although repeated seismic events occuring on the same fault might result in rotations of several degrees over geological time scales
Self-induced deformation on the fault plane during an earthquake part II: Continuous tangential displacements
No full textThis paper regards the on-fault displacement field generated by an earthquake on its own fault plane, with special attention to the tangential displacement vector. It is the continuation and the completion of a previous paper (ARMIGLIATO et al., 2003) concerning the analysis of the normal on-fault displacement component. It is here recognised that in addition to the discontinuous shear displacement, which is the main contribution to the seismic dislocation on the fault, there is a tangential displacement contribution that is continuous across the fault. The continuous tangential displacement is exclusively produced by the presence of the free earth's surface. The tangential displacement vector has non-vanishing components in both directions, parallel as well as perpendicular to the imposed uniform shear slip, the first being predominant on the second. We perform a set of computations aimed at evaluating the dependence of the tangential displacement magnitude on the relevant fault parameters for basic cases of rectangular faults embedded in a homogeneous half-space
Estrategias de acción frente a la incertidumbre
No full textReseña del Libro: Marcelo Manucci La estrategia de los cuatro círculos. Diseñar el futuro en la incertidumbre del presente Buenos Aires: Norma, 2006 isbn: 958-04-9660-
Estrategias de acción frente a la incertidumbre
No full textReseña del Libro: Marcelo Manucci La estrategia de los cuatro círculos. Diseñar el futuro en la incertidumbre del presente Buenos Aires: Norma, 2006 isbn: 958-04-9660-
Replication Data for: Where the wind blows: Five Star Movement’s populism, direct democracy and ideological flexibility
No full textThis dataset includes the corpus of online articles on which the paper is based.
In detail, the files provided are:
1) the full blog data that was downloaded and structured
(BG_BLOG_till2015_11_wTOPICS.enum.xml)
2) the full blog data that was downloaded and structured; additionally,
all the texts are parsed and the parses are saved in the XML file.
(BG_BLOG_till2015_11_wTOPICS.enum_spacy_parsed.xml)
3) a list of labels (categories) and corpus_IDs which refer to the content
labelled as being an example of this category. On this data we train the
nearest centroid classifier.
(labels_7cat_articles_numbers_only.txt)
4) same as the list before but with less labelled data (96 articles; like
in the paper)
(labels_7cat_articles_numbers_only_reduced96.txt)
5) a python script which replicates the results for the evaluation of
the nearest centroid classifier, using 5-fold cross-validation and addi-
tionally a leave-one-out evaluation for accuracy as well.
(nearest_centroid_eval.py
Coastal mass failure induced by the 1999 Izmit earthquake, Turkey: slope stability analysed through an advanced method of limit equilibrium
No full textReplication Data for: Where the wind blows: Five Star Movement’s populism, direct democracy and ideological flexibility
No full textThis dataset includes the corpus of online articles on which the paper is based.
In detail, the files provided are:
1) the full blog data that was downloaded and structured
(BG_BLOG_till2015_11_wTOPICS.enum.xml)
2) the full blog data that was downloaded and structured; additionally,
all the texts are parsed and the parses are saved in the XML file.
(BG_BLOG_till2015_11_wTOPICS.enum_spacy_parsed.xml)
3) a list of labels (categories) and corpus_IDs which refer to the content
labelled as being an example of this category. On this data we train the
nearest centroid classifier.
(labels_7cat_articles_numbers_only.txt)
4) same as the list before but with less labelled data (96 articles; like
in the paper)
(labels_7cat_articles_numbers_only_reduced96.txt)
5) a python script which replicates the results for the evaluation of
the nearest centroid classifier, using 5-fold cross-validation and addi-
tionally a leave-one-out evaluation for accuracy as well.
(nearest_centroid_eval.py
Resizing Lisowicia bojani. Volumetric body mass estimate and 3D reconstruction of the giant Late Triassic dicynodont
No full textBody size is one of the most crucial biological properties, with a major influence on ecology, metabolism and several physiological aspects. Recently the exceptionally large dicynodont Lisowicia bojani from the Late Triassic of Poland has been described. Using a regression formula based on long bone circumferences, an impressive body mass of 9.33 tons was reconstructed in the original description for this new and largest member of dicynodonts. The taxon is characterized by particularly robust long bones with very massive and stout shafts, thus raising the theoretical possibility that the regression formulae may have led to a substantial overestimate of the body mass. Here we present a new body mass estimate for Lisowicia based on 3D digital volumetric models, aiming to provide a more reliable and conservative estimate. The new body mass ranges from 4.87 tons to 7.02 tons for the adult taxon, with an average body mass of 5.88 tons; thus, the original value of 9.33 tons overestimates the weight of about 60%. Our study confirms empirically that volumetric methods for body mass estimates should be preferred and implemented whenever possible. Synapsids still had to wait until the Eocene to reach the enormous body mass of 9 tons
- …
