6,868 research outputs found

    Export-Oriented Policies, Women’s Work Burden and Human Development in Mauritius

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    This paper, looking at the case study of Mauritius, attempts to understand the factors affecting the relationship between EOP, women’s work burden along different social backgrounds. The analysis is based on between-method triangulation consisting of a quantitative survey in the industrial sector and a qualitative survey in the industrial and services sectors. The main result shows that women and the social reproductive process were not affected in the same way depending on the socioprofessional background of the woman

    Polynomial-Time Space-Optimal Silent Self-Stabilizing Minimum-Degree Spanning Tree Construction

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    Motivated by applications to sensor networks, as well as to many other areas, this paper studies the construction of minimum-degree spanning trees. We consider the classical node-register state model, with a weakly fair scheduler, and we present a space-optimal \emph{silent} self-stabilizing construction of minimum-degree spanning trees in this model. Computing a spanning tree with minimum degree is NP-hard. Therefore, we actually focus on constructing a spanning tree whose degree is within one from the optimal. Our algorithm uses registers on O(logn)O(\log n) bits, converges in a polynomial number of rounds, and performs polynomial-time computation at each node. Specifically, the algorithm constructs and stabilizes on a special class of spanning trees, with degree at most OPT+1OPT+1. Indeed, we prove that, unless NP == coNP, there are no proof-labeling schemes involving polynomial-time computation at each node for the whole family of spanning trees with degree at most OPT+1OPT+1. Up to our knowledge, this is the first example of the design of a compact silent self-stabilizing algorithm constructing, and stabilizing on a subset of optimal solutions to a natural problem for which there are no time-efficient proof-labeling schemes. On our way to design our algorithm, we establish a set of independent results that may have interest on their own. In particular, we describe a new space-optimal silent self-stabilizing spanning tree construction, stabilizing on \emph{any} spanning tree, in O(n)O(n) rounds, and using just \emph{one} additional bit compared to the size of the labels used to certify trees. We also design a silent loop-free self-stabilizing algorithm for transforming a tree into another tree. Last but not least, we provide a silent self-stabilizing algorithm for computing and certifying the labels of a NCA-labeling scheme

    Compact Deterministic Self-Stabilizing Leader Election: The Exponential Advantage of Being Talkative

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    This paper focuses on compact deterministic self-stabilizing solutions for the leader election problem. When the protocol is required to be \emph{silent} (i.e., when communication content remains fixed from some point in time during any execution), there exists a lower bound of Omega(\log n) bits of memory per node participating to the leader election (where n denotes the number of nodes in the system). This lower bound holds even in rings. We present a new deterministic (non-silent) self-stabilizing protocol for n-node rings that uses only O(\log\log n) memory bits per node, and stabilizes in O(n\log^2 n) rounds. Our protocol has several attractive features that make it suitable for practical purposes. First, the communication model fits with the model used by existing compilers for real networks. Second, the size of the ring (or any upper bound on this size) needs not to be known by any node. Third, the node identifiers can be of various sizes. Finally, no synchrony assumption, besides a weakly fair scheduler, is assumed. Therefore, our result shows that, perhaps surprisingly, trading silence for exponential improvement in term of memory space does not come at a high cost regarding stabilization time or minimal assumptions

    Silent MST approximation for tiny memory

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    In network distributed computing, minimum spanning tree (MST) is one of the key problems, and silent self-stabilization one of the most demanding fault-tolerance properties. For this problem and this model, a polynomial-time algorithm with O(log2 ⁣n)O(\log^2\!n) memory is known for the state model. This is memory optimal for weights in the classic [1,poly(n)][1,\text{poly}(n)] range (where nn is the size of the network). In this paper, we go below this O(log2 ⁣n)O(\log^2\!n) memory, using approximation and parametrized complexity. More specifically, our contributions are two-fold. We introduce a second parameter~ss, which is the space needed to encode a weight, and we design a silent polynomial-time self-stabilizing algorithm, with space O(logns)O(\log n \cdot s). In turn, this allows us to get an approximation algorithm for the problem, with a trade-off between the approximation ratio of the solution and the space used. For polynomial weights, this trade-off goes smoothly from memory O(logn)O(\log n) for an nn-approximation, to memory O(log2 ⁣n)O(\log^2\!n) for exact solutions, with for example memory O(lognloglogn)O(\log n\log\log n) for a 2-approximation

    Bound state in the vector channel of the extended Nambu--Jona-Lasinio model at fixed f_\pi

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    We show that, as a consequence of fixing f_\pi = 93 MeV: (1) a bound state pole in the J^P = 1^- scattering amplitude of the ENJL model exists for arbitrarily weak (positive) vector coupling G_2 so long as the constituent quark mass is sufficiently large; (2) there is a bound state for any quark mass when G_2 \geq 0.6/(8 f_\pi^2); (3) this bound state becomes massless at G_2 = 1/(8 f_\pi^2) and a tachyon for G_2 exceeding it. We show by way of an example that the model has no trouble fitting the \rho meson mass simultaneously with other observables.Comment: 9 pages, 2 (eps) figures, to appear in PL
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