Fast Discrete Consensus Based on Gossip for Makespan Minimization in Networked Systems

In this paper we propose a novel algorithm to solve the discrete consensus problem, i.e., the problem of distributing evenly a set of tokens of arbitrary weight among the nodes of a networked system. Tokens are tasks to be executed by the nodes and the proposed distributed algorithm minimizes monotonically the makespan of the assigned tasks. The algorithm is based on gossip-like asynchronous local interactions between the nodes. The convergence time of the proposed algorithm is superior with respect to the state of the art of discrete and quantized consensus by at least a factor O(n) in both theoretical and empirical comparisons

It’s not about the money! EU funds, local opportunities, and the Brexit vote. LEQS Paper No. 149/2019 November 2019

Growing Euroscepticism across the European Union (EU) leaves open questions as to what citizens expect to gain from EU Membership and what influences their dissent for the EU integration project. This paper looks at EU Structural Funds, one of the largest and most visible expenditure items in the EU budget, to test the impact of EU money on electoral support for the EU. By leveraging the Referendum on Brexit hold in the United Kingdom, a spatial RDD analysis offers causal evidence that EU money does not influence citizens’ support for the EU. Conversely, the analysis shows that EU funds contribute to mitigate Euroscepticism only where they are coupled with tangible improvements in the local labour market conditions. In order to gain support from its citizens, the European Union needs to produce tangible impacts, generating opportunities at the local level where these are felt the most by voters

A Decentralized Lifetime Maximization Algorithm for Distributed Applications in Wireless Sensor Networks

We consider the scenario of a Wireless Sensor Networks (WSN) where the nodes are equipped with a programmable middleware that allows for quickly deploying different applications running on top of it so as to follow the changing ambient needs. We then address the problem of finding the optimal deployment of the target applications in terms of network lifetime. We approach the problem considering every possible decomposition of an application's sensing and computing operations into tasks to be assigned to each infrastructure component. The contribution of energy consumption due to the energy cost of each task is then considered into local cost functions in each node, allowing us to evaluate the viability of the deployment solution. The proposed algorithm is based on an iterative and asynchronous local optimization of the task allocations between neighboring nodes that increases the network lifetime. Simulation results show that our framework leads to considerable energy saving with respect to both sink-oriented and cluster-oriented deployment approaches, particularly for networks with high node densities and non-uniform energy consumption or initial battery charge

A new approach for diagnosability analysis of Petri nets using Verifier Nets

In this paper, we analyze the diagnosability properties of labeled Petri nets. We consider the standard notion of diagnosability of languages, requiring that every occurrence of an unobservable fault event be eventually detected, as well as the stronger notion of diagnosability in K steps, where the detection must occur within a fixed bound of K event occurrences after the fault. We give necessary and sufficient conditions for these two notions of diagnosability for both bounded and unbounded Petri nets and then present an algorithmic technique for testing the conditions based on linear programming. Our approach is novel and based on the analysis of the reachability/coverability graph of a special Petri net, called Verifier Net, that is built from the Petri net model of the given system. In the case of systems that are diagnosable in K steps, we give a procedure to compute the bound K. To the best of our knowledge, this is the first time that necessary and sufficient conditions for diagnosability and diagnosability in K steps of labeled unbounded Petri nets are presented

On the Enforcement of a Class of Nonlinear Constraints on Petri Nets

International audienceThis paper focuses on the enforcement of nonlinear constraints in Petri nets. First, a supervisory structure is proposed for a nonlinear constraint. The proposed structure consists of added places and transitions. It controls the transitions in the net to be controlled only but does not change its states since there is no arc between the added transitions and the places in the original net. Second, an integer linear programming model is proposed to transform a nonlinear constraint to a minimal number of conjunc-tive linear constraints that have the same control performance as the nonlinear one. By using a place invariant based method, the obtained linear constraints can be easily enforced by a set of control places. The control places consist to a supervisor that can enforce the given nonlinear constraint. On condition that the admissible markings space of a nonlinear constraint is non-convex, another integer linear programming model is developed to obtain a minimal number of constraints whose disjunctions are equivalent to the nonlinear constraint. Finally, a number of examples are provided to demonstrate the proposed approach

Ressenyes

Index de les obres ressenyades: Franco SEPE, Fabrizia Ramondino. Rimemorazione e viaggi

UK’s less developed regions stand to suffer most when top-down EU funding is gone

Post Brexit, the ensuing lack of EU agricultural subsidies will have a detrimental effect on the less developed regions of the UK, potentially more so than the end to EU regional development funds that have been benefiting already fairly well-functioning constituencies. In this piece Riccardo Crescenzi and Mara Giua explain the (un)intended consequences of Brexit in this regard

Control of Safe Ordinary Petri Nets Using Unfolding

International audienceIn this paper we deal with the problem of controlling a safe place/transition net so as to avoid a set of forbidden markings "F" . We say that a given set of markings has property REACH if it is closed under the reachability operator. We assume that all transitions of the net are controllable and that the set of forbidden markings "F" has the property REACH. The technique of unfolding is used to design a maximally permissive supervisor to solve this control problem. The supervisor takes the form of a set of control places to be added to the unfolding of the original net. The approach is also extended to the problem of preventing a larger set "F" of impending forbidden marking. This is a superset of the forbidden markings that also includes all those markings from which—unless the supervisor blocks the plant—a marking in "F" is inevitably reached in a finite number of steps. Finally, we consider the particular case in which the control objective is that of designing a maximally permissive supervisor for deadlock avoidance and we show that in this particular case our procedure can be efficiently implemented by means of linear algebraic techniques

The EU cohesion policy in context: does a bottom-up approach work in all regions?

This paper looks at the European Union as a laboratory to study how ‘spatially-targeted’ policies (i.e. the EU Cohesion and Rural Development Policies) interact with sectoral ‘spatially-blind’ policies (i.e. the Common Agricultural Policy - CAP), jointly shaping regional growth dynamics. The analysis of the drivers of regional growth shows that the EU Regional Policy has a positive influence on economic growth in all regions. However, its impact is stronger in the most socio-economically advanced areas and is maximised when its expenditure is complemented by Rural Development and CAP funds. The top-down funding of the CAP seems to be able to concentrate some benefits in the most deprived areas of the Union. This suggests that bottom-up policies are not always the best approach to territorial cohesion. Top-down policies may – in some cases – be effective in order to channel resources to the most socio-economically deprived areas. Territorial cohesion requires the flexible integration and coordination of both bottom-up and top-down approaches

The EU Cohesion policy in context: regional growth and the influence of agricultural and rural development policies. LEQS Discussion Paper No. 85/2014 December 2014

This paper looks at the Cohesion Policy of the European Union (EU) and investigates how the EU agricultural and rural development policies shape its influence on regional growth. The analysis of the drivers of regional growth shows that the EU Regional Policy has a positive and significant influence on economic growth in all regions. However, its impact is stronger in the most socio-economically advanced areas and is maximised when its expenditure is complemented by Rural Development and Common Agricultural Policy (CAP) funds. The top-down funding of the CAP seems to be able to concentrate some benefits in the most deprived areas. Conversely only the most dynamics rural areas are capable of leveraging on the bottom-up measures of the EU Rural Development Policy. This suggests that EU policy makers in all fields should constantly look for the best mix of bottom-up and top-down measures in order to tackle structural disadvantage