Towards formal models and languages for verifiable Multi-Robot Systems

Incorrect operations of a Multi-Robot System (MRS) may not only lead to unsatisfactory results, but can also cause economic losses and threats to safety. These threats may not always be apparent, since they may arise as unforeseen consequences of the interactions between elements of the system. This call for tools and techniques that can help in providing guarantees about MRSs behaviour. We think that, whenever possible, these guarantees should be backed up by formal proofs to complement traditional approaches based on testing and simulation. We believe that tailored linguistic support to specify MRSs is a major step towards this goal. In particular, reducing the gap between typical features of an MRS and the level of abstraction of the linguistic primitives would simplify both the specification of these systems and the verification of their properties. In this work, we review different agent-oriented languages and their features; we then consider a selection of case studies of interest and implement them useing the surveyed languages. We also evaluate and compare effectiveness of the proposed solution, considering, in particular, easiness of expressing non-trivial behaviour.Comment: Changed formattin

Blind user detection in doubly-dispersive DS/CDMA channels

In this work, we consider the problem of detecting the presence of a new user in a direct-sequence/code-division-multiple-access (DS/CDMA) system with a doubly-dispersive fading channel, and we propose a novel blind detection strategy which only requires knowledge of the spreading code of the user to be detected, but no prior information as to the time-varying channel impulse response and the structure of the multiaccess interference. The proposed detector has a bounded constant false alarm rate (CFAR) under the design assumptions, while providing satisfactory detection performance even in the presence of strong cochannel interference and high user mobility.Comment: Accepted for publication on IEEE Transactions on Signal Processin

A Dual Hybrid Virtual Element Method for Plane Elasticity Problems

A dual hybrid Virtual Element scheme for plane linear elastic problems is presented and analysed. In particular, stability and convergence results have been established. The method, which is first order convergent, has been numerically tested on two benchmarks with closed form solution, and on a typical microelectromechanical system. The numerical outcomes have proved that the dual hybrid scheme represents a valid alternative to the more classical low-order displacement-based Virtual Element Method

Third molar maturity index by measurements of open apices in a Libyan sample of living subjects

In most countries, forensic age estimation in living subjects has become increasingly important in the last few years. In addition, as the age of legal majority ranges from 14 to 18 in many countries, and in Libya it is 18 years, radiographic assessment of the degree of third molar development is essential for forensic age estimation of adolescents and young adults. The aim of this paper is to assess the accuracy of the cut-off value of 0.08, by measurements of third molar index (I3M), in determining if a subject is adult or not in Libyan population. Digital panoramic radiographs of 307 healthy subjects (163 girls, 144 boys), aged between 14 and 22, were analysed. The I3M, the age and the sex of the subjects were used as predictive variable for age estimation. Using a cut-off of 0.08, the sensitivity of the test for boys was 90.9% and the specificity 100%. The proportion of correctly classified individuals was 95.1% (95% CI: 91.5–98.7%). The sensitivity for girls was 90.6% and the specificity 100%. The proportion of correctly classified individuals was 94.5% (95% CI: 90.9–98.1%). Estimated post-test probability in boys and girls was 100%. Further analyses, performed using a cut-off of 0.09, do not affect the specificity (100%) while they improve the sensitivity for both boys and girls

The Cartographic Reasoning in the Arctic. Modern Territorial Representations of the State in the Arctic Strategies of Norway, Russia and Finland.

In the late 2000s, the renewed interest of the Arctic States over the Arctic has been seen with international concern as a revival of hard-core geopolitics towards an area that became an example of cooperation among states and minorities. This apprehension is based on a simplistic conception of territory as the natural material manifestation of the State over the Earth, typical of classical geopolitics and the realist school of International Relations (IR). The scope of this thesis is thus twofold. Firstly, it aims at problematizing the often academically neglected concept of territory. It is only adopting Wendt’s social constructivist approach and the notion of the state “as-a-person”, which rationalizes its personhood and agency on the international scene, that I assume it is possible to understand the contemporary situation of the Arctic, where the Arctic States are intentionally acting as the legitimate actors, within the socio-cultural framework of the current International Legal System. Moreover, with the analysis of the sources of international law and how they manage and resolve territorial disputes, it will be argued Carl Schmitt’s previous conceptions of territorial sovereignty and geographical Order, described in the Nomos of the Earth, which is also at the roots of IR realism. My point is that, following Stuart Elden’s insight, territory is indeed a political technological tool, whose technological aspects are represented by cartography which influences subtly the way we relates to the World and eventually even the patterns of the modern nation-state through what Franco Farinelli calls the cartographic reasoning. Such logic is best expressed by the three characteristics of continuity, homogeneity and isotropy, that ‘stemming from the map’ are the attribute themselves of the modern state. The categorization of these three features through the methodological means of Norman Fairclough’s Critical Discourse Analysis will provide an initial analytical framework for the Arctic Strategy documents of Norway, Russia and Finland. Considering them as the performative territorial representation of the state, it will be possible to prove whether the Arctic States are actually turning back to hard national interest-based policies, or some post-modern spatial aspect is predominating. The findings are promising on the analytical side, showing the appropriate flexibility for texts and maps, and illustrate that the Arctic States are ‘still on the Map’, managing to adapt global phenomena in the terms of cartographic reasoning, reaffirming thus their leading role in the determination of political space. Keywords: Arctic, Arctic Strategies, territory, territoriality, social constructivism, State-as-a-person, international law, effectivity, Carl Schmitt, Nomos of the Earth, UNCLOS, cartography, cartographic reasoning, political geography

Strong unique continuation and local asymptotics at the boundary for fractional elliptic equations

We study local asymptotics of solutions to fractional elliptic equations at boundary points, under some outer homogeneous Dirichlet boundary condition. Our analysis is based on a blow-up procedure which involves some Almgren type monotonicity formulae and provides a classification of all possible homogeneity degrees of limiting entire profiles. As a consequence, we establish a strong unique continuation principle from boundary points.Comment: 40 pages, 2 figure

Accuracy and precision of an intraoral scanner in complex prosthetic rehabilitations: an in vitro study

The main purpose of this study is to measure the accuracy and the precision of the intraoral optical scanner CS3500® (Carestream Dental LLC, Atlanta, USA) in complex clinical situations as full arch rehabilitations on impl ants. 50 scans of the acrylic resin model were performed by using CS3500® (Carestream Dental LLC, Atlanta, USA) scanner. Each scan was compared with the virtual model derived from scanning with the laboratory scanner Dscan3® (Enhanced Geometry Soluti on, Bologna, Italy) to measure a possible misalignment. The alignment error was found to be 79,6 ( ± 12,87)  m. The measurement was taken at the level of 2 distal scan - abutments. The scanner's precision ranges from 24 to 52  m , depending on the dist ance between scan - abutment. CS3500® (Carestream Dental LLC, Atlanta, USA) intraoral scanner has detected a valid device in the execution of complex rehabilitations on implants. His accuracy and precision values fall within the range established in li terature to define acceptable the prosthetic fitting on full arch implant rehabilitation