Search results for "102"
showing 10 items of 2892 documents
Effect of the thermal storage dimensions on the performances of solar photovoltaic-thermal systems
2020
Abstract PV/T panels are innovative systems increasingly used in the building sector. As a matter of fact, in that context they allow a set of common problems to be addressed and often solved: lack of physical space and economic issues, always existing when PV and thermal panels are to be installed separately. Obviously, the main objective of PV/T panels is to enhance the electrical efficiency by cooling the PV cells, but the side positive effect is also the production of thermal energy, which can be suitably exploited with a proper configuration of the whole system and an appropriate design of its components. Their energy production and overall efficiency depend on several factors and ther…
A genetic approach to the maximum common subgraph problem
2019
Finding the maximum common subgraph of a pair of given graphs is a well-known task in theoretical computer science and with considerable practical applications, for example, in the fields of bioinformatics, medicine, chemistry, electronic design and computer vision. This problem is particularly complex and therefore fast heuristics are required to calculate approximate solutions. This article deals with a simple yet effective genetic algorithm that finds quickly a solution, subject to possible geometric constraints.
Obsidian from the Neolithic Layers of “Grotta di San Michele Arcangelo di Saracena” (Cosenza), Italy. A Preliminary Report
2021
Abstract The paper presents the results obtained by techno-typological analysis of a lithic assemblage from the Neolithic layers of Grotta San Michele Arcangelo di Saracena (Cosenza) together with the results of micro-wear analysis obtained from a preliminary selection of obsidian artifacts with different provenances distinguished by pXRF analysis. The site provides one of the best preserved Neolithic sequences in the area, from the earliest Impressed Wares (or Impresse Arcaiche) (early sixth millennium BC) to the Spatarella pottery style (end fifth – early fourth millennium BC). Along the Neolithic sequence, it is possible to observe some major changes within lithic resources management. I…
The beginning of the Neolithic in Southern Italy and Sicily
2018
Abstract The process of Neolithization of Southern Italy and Sicily covers about 500 years (6200–5700 cal BC) and involves two cultural horizons: Archaic Impressed Ware or “Impresse Arcaiche” and Advanced Impressed Ware or “Impresse Evolute”. In Southern Italy the Neolithic peopling from the East is characterized by a “package” of plenty domesticated plants and livestock; in Sicily the adoption of the new economical system is apparently more slow and with no evidences of ruptures between the Mesolithic groups and first farmers. In this paper we present the chronological and cultural framework of the sixth millennium BC within the area of investigation, with an up-to-date bibliography about …
Within the symbolic world of the prehistoric hunters: A GIS-based and 3D model analysis of sites with complexes of linear incisions in western Sicily
2021
Abstract The prehistoric peopling of Sicily has left scattered traces of symbolic activities through well-known rock art expressions in caves and rock shelters located all around the island (among the most significant, the sites of Addaura, Racchio and Genovese). A peculiar phenomenon is the incision of linear signs, often grouped on the same rocky walls, hidden in fissures or placed at the entrance of the underground chambers of caves. In this report, we investigate a sample of these graphic expressions from a spatial and technical point of view. A GIS-based approach presents the territorial pattern providing insight, on a macroscale, into the intentional positioning of the sign complexes.…
Probabilistic squares and hexagons of opposition under coherence
2017
Various semantics for studying the square of opposition and the hexagon of opposition have been proposed recently. We interpret sentences by imprecise (set-valued) probability assessments on a finite sequence of conditional events. We introduce the acceptability of a sentence within coherence-based probability theory. We analyze the relations of the square and of the hexagon in terms of acceptability. Then, we show how to construct probabilistic versions of the square and of the hexagon of opposition by forming suitable tripartitions of the set of all coherent assessments on a finite sequence of conditional events. Finally, as an application, we present new versions of the square and of the…
Evolutionary processes in the emergence and recent spread of the syphilis agent, Treponema pallidum
2022
Abstract The incidence of syphilis has risen worldwide in the last decade in spite of being an easily treated infection. The causative agent of this sexually transmitted disease is the bacterium Treponema pallidum subspecies pallidum (TPA), very closely related to subsp. pertenue (TPE) and endemicum (TEN), responsible for the human treponematoses yaws and bejel, respectively. Although much focus has been placed on the question of the spatial and temporary origins of TPA, the processes driving the evolution and epidemiological spread of TPA since its divergence from TPE and TEN are not well understood. Here, we investigate the effects of recombination and selection as forces of genetic diver…
On Shimura subvarieties of the Prym locus
2018
We show that families of Pryms of abelian Galois covers of $\mathbb{P}^1$ in $A_{g-1}$ (resp. $A_g$) do not give rise to high dimensional Shimura subvareties.
The Oort conjecture on Shimura curves in the Torelli locus of hyperelliptic curves
2017
Abstract Oort has conjectured that there do not exist Shimura varieties of dimension >0 contained generically in the Torelli locus of genus-g curves when g is sufficiently large. In this paper we prove the analogue of this conjecture for Shimura curves with respect to the hyperelliptic Torelli locus of genus g > 7 .
Shock formation in the dispersionless Kadomtsev-Petviashvili equation
2016
The dispersionless Kadomtsev-Petviashvili (dKP) equation $(u_t+uu_x)_x=u_{yy}$ is one of the simplest nonlinear wave equations describing two-dimensional shocks. To solve the dKP equation we use a coordinate transformation inspired by the method of characteristics for the one-dimensional Hopf equation $u_t+uu_x=0$. We show numerically that the solutions to the transformed equation do not develop shocks. This permits us to extend the dKP solution as the graph of a multivalued function beyond the critical time when the gradients blow up. This overturned solution is multivalued in a lip shape region in the $(x,y)$ plane, where the solution of the dKP equation exists in a weak sense only, and a…