arXiv subjects

Antonio Sassano

Publications and source records attributed to Antonio Sassano.

6 recordsLinked to original sources

arXiv2023

Power Reduction in FM Networks by Mixed-Integer Programming. A Case Study

The climate change emergency calls for a reduction in energy consumption in all human activities and production processes. The radio broadcasting industry is no exception. However, reducing energy requirements by uniformly cutting the radiated power at every transmitter can potentially impair the quality of service. A careful evaluation and optimization study are in order. In this paper, by analyzing the Italian frequency modulation analog broadcasting service, we show that it is indeed possible to significantly reduce the energy consumption of the broadcasters without sacrificing the quality of the service, rather, even getting improvements.

math.OC↗

arXiv2019

An ${\cal O}(n^2 \log(n))$ algorithm for the weighted stable set problem in claw-free graphs

A graph $G(V, E)$ is \emph{claw-free} if no vertex has three pairwise non-adjacent neighbours. The Maximum Weight Stable Set (MWSS) Problem in a claw-free graph is a natural generalization of the Matching Problem and has been shown to be polynomially solvable by Minty and Sbihi in 1980. In a remarkable paper, Faenza, Oriolo and Stauffer have shown that, in a two-step procedure, a claw-free graph can be first turned into a quasi-line graph by removing strips containing all the irregular nodes and then decomposed into \emph{\{claw, net\}-free} strips and strips with stability number at most three. Through this decomposition, the MWSS Problem can be solved in ${\cal O}(|V|(|V| \log |V| + |E|))$ time. In this paper, we describe a direct decomposition of a claw-free graph into \emph{\{claw, net\}-free} strips and strips with stability number at most three which can be performed in ${\cal O}(|V|^2)$ time. In two companion papers we showed that the MWSS Problem can be solved in ${\cal O}(|E| \log |V|)$ time in claw-free graphs with $α(G) \le 3$ and in ${\cal O}(|V| \sqrt{|E|})$ time in \{claw, net\}-free graphs with $α(G) \ge 4$. These results prove that the MWSS Problem in a claw-free graph can be solved in ${\cal O}(|V|^2 \log |V|)$ time, the same complexity of the best and long standing algorithm for the MWSS Problem in \emph{line graphs}.

cs.DM↗

arXiv2017

GUB Covers and Power-Indexed formulations for Wireless Network Design

We propose a pure 0-1 formulation for the wireless network design problem, i.e. the problem of configuring a set of transmitters to provide service coverage to a set of receivers. In contrast with classical mixed integer formulations, where power emissions are represented by continuous variables, we consider only a finite set of powers values. This has two major advantages: it better fits the usual practice and eliminates the sources of numerical problems which heavily affect continuous models. A crucial ingredient of our approach is an effective basic formulation for the single knapsack problem representing the coverage condition of a receiver. This formulation is based on the GUB cover inequalities introduced by Wolsey (1990) and its core is an extension of the exact formulation of the GUB knapsack polytope with two GUB constraints. This special case corresponds to the very common practical situation where only one major interferer is present. We assess the effectiveness of our formulation by comprehensive computational results over realistic instances of two typical technologies, namely WiMAX and DVB-T.

math.OC↗

arXiv2017

Negative Cycle Separation in Wireless Network Design

The Wireless Network Design Problem (WND) consists in choosing values of radio-electrical parameters of transmitters of a wireless network, to maximize network coverage. We present a pure 0-1 Linear Programming formulation for the WND that may contain an exponential number of constraints. Violated inequalities of this formulation are hard to separate both theoretically and in practice. However, a relevant subset of such inequalities can be separated more efficiently in practice and can be used to strengthen classical MILP formulations for the WND. Preliminary computational experience confirms the effectiveness of our new technique both in terms of quality of solutions found and provided bounds.

math.OC↗

arXiv2015

An ${\cal O}(n\sqrt{m})$ algorithm for the weighted stable set problem in {claw, net}-free graphs with $α(G) \ge 4$

In this paper we show that a connected {claw, net}-free graph $G(V, E)$ with $α(G) \ge 4$ is the union of a strongly bisimplicial clique $Q$ and at most two clique-strips. A clique is strongly bisimplicial if its neighborhood is partitioned into two cliques which are mutually non-adjacent and a clique-strip is a sequence of cliques $\{H_0, \dots, H_p\}$ with the property that $H_i$ is adjacent only to $H_{i-1}$ and $H_{i+1}$. By exploiting such a structure we show how to solve the Maximum Weight Stable Set Problem in such a graph in time ${\cal O}(|V|\sqrt{|E|})$.

cs.DM↗

arXiv2015

An ${\cal O}(m\log n)$ algorithm for the weighted stable set problem in claw-free graphs with $α({G}) \le 3$

In this paper we show how to solve the \emph{Maximum Weight Stable Set Problem} in a claw-free graph $G(V, E)$ with $α(G) \le 3$ in time ${\cal O}(|E|\log|V|)$. More precisely, in time ${\cal O}(|E|)$ we check whether $α(G) \le 3$ or produce a stable set with cardinality at least $4$; moreover, if $α(G) \le 3$ we produce in time ${\cal O}(|E|\log|V|)$ a maximum stable set of $G$. This improves the bound of ${\cal O}(|E||V|)$ due to Faenza et al.

cs.DM↗