Search results for "rete"

Monotonicity-based inversion of the fractional Schr\"odinger equation II. General potentials and stability

2019

In this work, we use monotonicity-based methods for the fractional Schr\"odinger equation with general potentials $q\in L^\infty(\Omega)$ in a Lipschitz bounded open set $\Omega\subset \mathbb R^n$ in any dimension $n\in \mathbb N$. We demonstrate that if-and-only-if monotonicity relations between potentials and the Dirichlet-to-Neumann map hold up to a finite dimensional subspace. Based on these if-and-only-if monotonicity relations, we derive a constructive global uniqueness results for the fractional Calder\'on problem and its linearized version. We also derive a reconstruction method for unknown obstacles in a given domain that only requires the background solution of the fractional Sch…

Coincidence problems for generalized contractions

2014

In this paper, we establish some new existence, uniqueness and Ulam-Hyers stability theorems for coincidence problems for two single-valued mappings. The main results of this paper extend the results presented in O. Mle?ni?e: Existence and Ulam-Hyers stability results for coincidence problems, J. Non-linear Sci. Appl., 6(2013), 108-116. In the last section two examples of application of these results are also given.

A Hardware and Secure Pseudorandom Generator for Constrained Devices

2018

Hardware security for an Internet of Things or cyber physical system drives the need for ubiquitous cryptography to different sensing infrastructures in these fields. In particular, generating strong cryptographic keys on such resource-constrained device depends on a lightweight and cryptographically secure random number generator. In this research work, we have introduced a new hardware chaos-based pseudorandom number generator, which is mainly based on the deletion of an Hamilton cycle within the $N$ -cube (or on the vectorial negation), plus one single permutation. We have rigorously proven the chaotic behavior and cryptographically secure property of the whole proposal: the mid-term eff…

Gas-liquid chromatographic analyses

1983

Abstract The gas chromatography of mixtures of n -alkyl acetates (CH 3 COOR, R = C 1 —C 8 ) and methyl esters of aliphatic n -carboxylic acids (R′COOCH 3 , R′ = C 1 —C 8 ) and certain of their monochlorinated derivatives has been studied on Carbowax 20M and SE-30 glass capillary columns under the same operating conditions. The separation of the isomeric monochlorinated esters was complete on Carbowax 20M, whereas on SE-30 the peaks of 6- and 7-chlorooctyl acetates and methyl (ω − 1)- and (ω − 2)-chlorooctanoates and -nonanoates partly overlapped. The complete separation of the mixtures could not be achieved, however, on Carbowax 20M, in spite of the use of various operating conditions. The …

A Sokoban-type game and arc deletion within irregular digraphs of all sizes

2007

Continuous images of arcs: Extensions of Cornette's Theorem

2015

In [J.L. Cornette “Image of a Hausdorff arc” is cyclically extensible and reducible Trans. Am. Math. Soc., 199 (1974), pp. 253–267], Cornette proved that a locally connected Hausdorff continuum X is the continuous image of an arc if and only if each of its cyclic elements is the continuous image of an arc. Cyclic elements form a closed null cover of X by retracts of X. We generalize Cornette's result to closed null covers of X with a dendritic structure. We give examples to show that some of our conditions are necessary and we pose some open questions.

The Windy clustered prize-collecting arc-routing problem

2011

This paper introduces the windy clustered prize-collecting arc-routing problem. It is an arc-routing problem where each demand edge is associated with a profit that is collected once if the edge is serviced, independent of the number of times the edge is traversed. It is further required that if a demand edge is serviced, then all the demand edges of its component are also serviced. A mathematical programming formulation is given and some polyhedral results including several facet-defining and valid inequalities are presented. The separation problem for the different families of inequalities is studied. Numerical results from computational experiments are analyzed. © 2011 INFORMS.

Visioni Metropolitane. Uno studio comparato tra l'Area Metropolitana di Palermo e la Comunidad de Madrid

2008

Il tema delle reti ecologiche e della connettività ecologica è diventato centrale per le politiche territoriali, segnando il passaggio da una politica protezionistica di aree chiuse ad una tutela ambientale diffusa attraverso percorsi di integrazione tra sviluppo territoriale sostenibile e conservazione della natura. Per indagare tale argomento, si deve inevitabilmente affrontare, e provare a superare, il nodo del ruolo del sistema delle reti ecologiche all’interno delle discipline che si occupano di pianificazione territoriale. A tal fine risulta necessario cercare di capire come mettere in relazione la Rete Ecologica, sistema che fornisce un elemento in più di conoscenza – ecologica – del…

Increasing chains and discrete reflection of cardinality

2013

Combining ideas from two of our previous papers, we refine Arhangel'skii Theorem by proving a cardinal inequality of which this is a special case: any increasing union of strongly discretely Lindelof spaces with countable free sequences and countable pseudocharacter has cardinality at most continuum. We then give a partial positive answer to a problem of Alan Dow on reflection of cardinality by closures of discrete sets.

Optimal Guard Placement Problem Under L-Visibility

2006

Two points a and b in the presence of polygonal obstacles are L-visible if the length of the shortest path avoiding obstacles is no more than L. For a given convex polygon Q, Gewali et al [4]. addressed the guard placement problem on the exterior boundary that will cover the maximum area exterior to the polygon under L-visibility. They proposed a linear time algorithm for some given value of L. When the length L is greater than half of the perimeter, they declared that problem as open. Here we address that open problem and present an algorithm whose time complexity is linear in number of vertices of the polygon.