Optimal fault-tolerant placement of relay nodes in a mission critical wireless network

The operations of many critical infrastructures (e.g., airports) heavily depend on proper functioning of the radio communication network supporting operations. As a result, such a communication network is indeed a mission-critical communication network that needs adequate protection from external electromagnetic interferences. This is usually done through radiogoniometers. Basically, by using at least three suitably deployed radiogoniometers and a gateway gathering information from them, sources of electromagnetic emissions that are not supposed to be present in the monitored area can be localised. Typically, relay nodes are used to connect radiogoniometers to the gateway. As a result, some degree of fault-tolerance for the network of relay nodes is essential in order to offer a reliable monitoring. On the other hand, deployment of relay nodes is typically quite expensive. As a result, we have two conflicting requirements: minimise costs while guaranteeing a given fault-tolerance. In this paper address the problem of computing a deployment for relay nodes that minimises the relay node network cost while at the same time guaranteeing proper working of the network even when some of the relay nodes (up to a given maximum number) become faulty (fault-tolerance). We show that the above problem can be formulated as a Mixed Integer Linear Programming (MILP) as well as a Pseudo-Boolean Satisfiability (PB-SAT) optimisation problem and present experimental results com- paring the two approaches on realistic scenarios

Enriching APSI with Validation Capabilities: the KEEN environment and its use in Robotics

This paper presents the KnowledgE ENgineering (KEEN) design support system in which Validation and Verification (V&V) methods are used to strengthen onground development of software for plan-based autonomy. In particular, the paper describes a collection of verification methods, based on Timed Game Automata (TGA), deployed for the design and development of timeline-based Planning and Scheduling (P&S) applications within the APSI-TRF framework. The KEENs V&V functionalities are illustrated describing software development to synthesize plans for a planetary rover

VALIDATION OF MESOSCALE METEOROLOGICAL SIMULATION OVER PO VALLEY FOR AIR QUALITY APPLICATIONS

Very high ground level concentrations of PM in winter and of ozone in summer often occur in Northern Italy, due to the high anthropogenic emissions and frequent stagnant meteorological conditions that characterize the area. These problems are not only related to urban, but also to suburban areas through the entire Po Valley. In such a situation it is important to use deterministic Chemical Transport Models, that allows to evaluate the effect of different air quality control policies on secondary pollution concentrations. Chemical Transport Models generally are part of more complex deterministic modelling systems, encompassing also emission models, meteorological models, and initial and boundary condition processors. Meteorological models are an important module of deterministic modelling systems and, due to their complexity, require high computational costs to perform simulations. In fact they solve a full set of non-hydrostatic equations that describe atmospheric dynamics and thermodynamics, and conservation equations, usually considering two-way interacting nested domains. Within the HPC-EUROPA (Pan-European Research Infrastructure on High Performance Computing) cooperation project, that allows to use clusters of CPUs all around Europe, the meteorological fields over Northern Italy were simulated using RAMS4.4 in parallel mode, creating a database for future air quality assessments. In the present work a CPUs cluster of the Italian computing centre CINECA have been used. The meteorological simulations have been performed considering three nested grids. The first grid covers an area that encompasses the entire Europe, the second grid is focused on Mediterranean sea, while the third one is limited to the Po Valley area. The spatial resolution of the three grids is respectively 128 km, 32 km and 8 km. The number of cells for the three grids is respectively 40x40, 86x86 and 102x102, with 33 vertical levels covering the domain from surface to roughly 20 km height. The entire 2004 year has been simulated through 72 simulations of 126 hours each, considering a spin-up time of 6 hours and 16 CPUs each simulation. In this paper the model configuration and the validation of the simulated meteorological fields are presented

An extensible architecture for robust multimodal human-robot communication

Abstract-Human safety and effective human-robot communication are main concerns in HRI applications. In order to achieve such goals, a system should be very robust, allowing little chance for misunderstanding the user's commands. Moreover, the system should permit natural interaction reducing the time and the effort needed to achieve tasks. The main purpose of this work is to develop a general framework for flexible and multimodal human-robot communication. The proposed architecture should be easy to modify and expand, adding or modifying input channels and changing the multimodal fusion strategies. In this paper, we introduce our general approach and provide a case study with two modalities (gesture and speech)

A Feasibility Study of an Integral PWR for Space Applications

Fission space power systems are well suited to provide safe, reliable, economic and robust energy sources, in the order of 100 KWe. A preliminary feasibility study of a nuclear fission reactor is here presented with the following requirements: i) high reliability, ii) R&D program of moderate cost, iii) to be deployed within a reasonable period of time (e.g. 2015), iv) to be operated and controlled for a long time (10 years) without human intervention, v) possibly to be also used as a byproduct for some particular terrestrial application (or at least to share common technologies), vi) to start with stationary application. The driving idea is to extend as much as possible the PWR technology, by recurring to an integral type reactor. Two options are evaluated for the electricity production: a Rankine steam cycle and a Rankine organic fluid cycle. The neutronics calculation is based on WIMS code benchmarked with MCNP code. The reactivity control is envisaged by changing the core geometry. The resulting system appears viable and of reasonable size, well fit to the present space vector capabilities. Finally, a set of R&D needs has been identified: cold well, small steam turbines, fluid leakage control, pumps, shielding, steam generator in low-gravity conditions, self pressurizer, control system. A R&D program of reasonable extent may yield the needed answers, and some demanding researches are of interest for the new generation Light Water Reactors

A Framework for Integrated Assessment Modelling

“Air quality plans” according to Air Quality Directive 2008/50/EC Art. 23 are the strategic element to be developed, with the aim to reliably meet ambient air quality standards in a cost-effective way. This chapter provides a general framework to develop and assess such plans along the lines of the European Commission’s basic ideas to implement effective emission reduction measures at local, region, and national level. This methodological point of view also allows to analyse the existing integrated approaches