Riviste Online SApienza - R.O.SA - 2 (Sapienza University of Rome)
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Pricing of a long-term care annuity with withdrawal guarantee using the exact individual trajectories method
No full textThe present work aims at evaluating Long-Term Care annuity contracts with Guaranteed Lifetime Withdrawal Benefits using the method of the Exact Individual Trajectories. This model, basically developed for the management of pension funds, is setup on an axiomatic basis and allows a complete description of the sample space. In addiction the financial component of the contract is modelled through the Heston model which considers stochastic both the stock price and the volatility
Capture-recapture models for official statistics in presence of out-of-scope units: an overview
Get PDFDuring the last years, National Statistics Institutes have been exploring the possibility to produce statistics based on administrative data only. In particular, the interest in populations’ size estimation is increasing. However, some issues naturally emerge since the aims of those who collect data and those who use them differ. On the one hand, it is very likely to have out-ofscope units in the datasets. On the other hand, some units that belong to the target population are not observed. In practice, this is the case of incomplete contingency tables that include some overcounts. The aim of this paper is to review the main and most recent literature dealing with the population size estimation problem, with an insight on the overcoverage issue
Landslide susceptibility mapping using logistic regression and frequency ratio approaches, case study from Souk Ahras region, N E Algeria
No full textLandslides are the most active process of soil erosion and landscape evolution; it is controlled by a set of non-linear factors. Therefore, a large amount of spatial data must be considered and analyzed in order to achieve some degree of prediction about it. Landslide susceptibility assessment (LSA) is carried out using various statistical modeling techniques among which figures the logistic regression (LR) and the Frequency Ratio (FR) models. This work allowed producing landslide susceptibility maps (LSMs) on a geographic information system (GIS) platform using LR and FR methods in the Northwest of Souk Ahras region, N E of Algeria. Landslide inventory map was established from visual interpretation of satellite images and field survey data. Slope instability phenomena in this region are related to a large variety of factors pertaining to the geological, geomorphological, hydrological and climate characteristics of the terrain. Consequently, a spatial database of seven causal factors were identified and used for predicting landslide prone areas. LSMs produced using LR and FR statistical models subdivided into five classes according to their degree of susceptibility to landslides: very low, low, moderate, high and very high. These rasters based LSMs was compared and verified with both training and testing inventory datasets. The AUC (area under the curve) was used for model evaluation. Results showed that the LR model provides a higher prediction accuracy of the LS mapping than the FR model with an AUC based on success rate equal 90.45 % and that based on prediction rate was 91.81 %. In addition, the results showed that about 30% to 37% of the study area was located in high and very high hazard classes. The resulting LSMs play an indispensable role in the region management and can be used in sustainable development planning
Rediscovery of a species considered to be extinct in the Pollino massif (Calabria, Italy): Erebia gorge (Hübner, [1804]) (Lepidoptera: Nymphalidae)
Get PDFAfter about 40 years, the presence of Erebia gorge (Hübner, [1804]) has been reconfirmed in the Pollino massif (Calabria, Italy). In July 2019, two specimens (1 ♂ and 1 ♀) were captured in the zone of Monte Pollino cliffs on the east face of the massif at a height of 1990 m. Given the isolation of the population at the southernmost limit of the species’ range, and the fact that this population is seriously threatened by global climate change, it would be of great value to conduct an exhaustive study of the distribution of the species throughout Pollino and of the genetic characteristics of this local population that could differ substantially from other Italian and European populations
New or little-known bees from Sicily (Hymenoptera: Apoidea)
Get PDFThe authors report newly recorded species of bees (Hymenoptera, Apoidea) on the Volcan Etna (Sicily). A total of ten species belonging to three families are recorded: Halictidae (8 species), Megachilidae (1 species), and Apidae (1 species). Pseudapis valga (Gerstaecker), Lasioglossum convexiusculum (Schenck) (Halictidae), Hoplitis laevifrons (Morawitz) (Megachilidae) and Tarsalia ancyliformis Popov (Apidae), are reported for the first time for Sicily and the presence of other bee species is confirmed for the Island. Furthermore, this is the first record of the genus Tarsalia Morawitz for the fauna of Sicily. For each species data are given in relation to the altitudinal level, the plants visited, and the ecological quality of the sites where the specimens were found
Description of the unknown males of three Chinese Meligethes (Coleoptera: Nitidulidae, Meligethinae)
Get PDFIn this paper we present the description of male genitalia and additional information on taxonomy of three recently described and poorly known Chinese endemic members of the genus Meligethes Stephens, 1830, Meligethes (Odonthogethes) brassicogethoides Audisio, Sabatelli and Jelínek, 2015, M. (O.) inexpectatus Liu, Huang, Cline, Sabatelli and Audisio, 2017, and M. (O.) tricuspidatus Liu, Huang, Cline and Audisio, 2018
New perspectives of public space. The MAXXI case study
No full textThe aim of this research it to propose a case study useful for reflecting on the nature and function of new forms of utilization public spaces. The case study analyses the MAXXI museum in Rome, which tuned to be a spontaneous form of public space, and expresses a clear need for an alternative, safe, cultural, innovative, contemporary public space
Influence of geological complexities on local seismic response in the municipality of Forio (Ischia Island, Italy)
Get PDFSeismic response studies carried out in the Municipality of Forio on Ischia (NA), southern Italy, following the 21st August 2017 earthquake allowed to detect local effects related to specific geological-structural settings that reflect the complexity of the volcanic context which characterises the entire island of Ischia and, more specifically, the western sector of Mt. Epomeo and the adjacent coastal plain of Forio. In particular, the following features have been observed: i) polarization and amplification effects in the proximity of tectonic elements that dissect the Zaro promontory, where volcanic deposits from massive to stratified widely outcrop; ii) stratigraphic resonances on significantly variable frequency values, changing within distances of a few hundred meters, which can be related to the juxtaposition of landslide debris (such as debris-/rock-avalanches and lahar) in correspondence with the town of Forio; iii) seismic amplification in the sector involved in the ongoing gravitational deformation of Mt. Nuovo even in the absence of polarization of the particle motion. The peculiarities of the geological contexts analysed in the Forio Municipality allow to apply different interpretative schemes that vary from stratigraphic resonance (one-dimensional model of resonant column) mostly controlled by thickness and wave velocity in soft soils onto a stiff bedrock, to the resonance of jointed rock masses which are not completely released from the adjacent bedrock so avoiding typical free vibrations with normal modes (three-dimensional oscillating mass model), or to the interaction in the ear surface with physical discontinuities responsible for modifying the physical properties of surface waves polarizing and amplifying them. The collected evidence of local seismic response in Forio exemplifies how not conventional interpretative keys for seismic zoning can be proposed to identify sectors whose response schemes do not necessarily fall within the standard of stratigraphic or topographical amplification adopted by current national guidelines for Seismic Microzonation (SM) studies. In particular, the evidence of local seismic response collected for the Forio Municipality were taken into account in the SM and relative products that were realised in the following years
Sines breakwater harbour: the OSOM+ monitoring program
Get PDFThe current program of Systematic Observation of Maritime Works (OSOM+), under development at the National Laboratory for Civil Engineering (LNEC), is essentially applied to rubble mound breakwaters. The OSOM’s main objective is to monitor the behaviour of maritime structures under inspection and recommend timely interventions for their maintenance and/or repair as to properly maintain its function during its lifetime. There are four main components of the OSOM+ program, namely: the periodic visual inspections made by a trained technician, where a set of photos and videos are taken at notable points along the structure and there is an identification of the main focuses of degradation of the structure; the periodic aerial inspections with an unmanned aerial vehicle (UAV) or drone, where individual aerial photographs are captured in a regularpattern and in the vertical direction, and from them orthomosaics, point clouds and/or profiles are obtained; the ANOSOM_WEB-based online platform, to store and/or query obtained information on the observation campaigns, as well as to diagnose present, evolution and risk conditions of the structure; and a mobile, portable, application for real-time input and visualization of the database information. This paper presents an application of the OSOM+ program to the study case: the west breakwater of the port of Sine