Measurement of D0^0 v2_2 in Pb-Pb collisions at sNN=2.76\sqrt{s_{NN}}=2.76 TeV with ALICE at the LHC

The study particle azimuthal anisotropy in heavy-ion collisions provides insight on the collective hydrodynamic expansion of the system and on its equation of state. The measurement of the elliptic flow, $v_2$, of D mesons compared to that of light hadrons is expected to be sensitive to the degree of thermalization of charm quarks within the quark-gluon plasma. The first measurement of D$^0$ meson $v_2$ with the ALICE detector at the LHC will be presented. The preliminary results obtained with the first Pb-Pb run at LHC show a hint of non-zero $v_2$ in $2<p_{\rm t} <5$ GeV/$c$.Comment: 6 pages, SQM 2011 Conference Proceeding

Just design

Inclusive design prescribes addressing the needs of the widest possible audience in order to consider human differences. Taking differences seriously, however, may imply severely restricting “the widest possible audience”. In confronting this paradox, we investigate to what extent Rawls’ theory of justice as fairness applies to design. By converting the paradox into the question of how design can be fair, we show that the demand for equitability shifts from the design output to the design process. We conclude that the two main questions about justice find application in design: the question about the standards of justice and the question about its metrics. We endorse a Rawlsian approach to the former, while some revision may be due regarding the latter

Resilience of Traffic Networks with Partially Controlled Routing

This paper investigates the use of Infrastructure-To-Vehicle (I2V) communication to generate routing suggestions for drivers in transportation systems, with the goal of optimizing a measure of overall network congestion. We define link-wise levels of trust to tolerate the non-cooperative behavior of part of the driver population, and we propose a real-time optimization mechanism that adapts to the instantaneous network conditions and to sudden changes in the levels of trust. Our framework allows us to quantify the improvement in travel time in relation to the degree at which drivers follow the routing suggestions. We then study the resilience of the system, measured as the smallest change in routing choices that results in roads reaching their maximum capacity. Interestingly, our findings suggest that fluctuations in the extent to which drivers follow the provided routing suggestions can cause failures of certain links. These results imply that the benefits of using Infrastructure-To-Vehicle communication come at the cost of new fragilities, that should be appropriately addressed in order to guarantee the reliable operation of the infrastructure.Comment: Accepted for presentation at the IEEE 2019 American Control Conferenc

Secure Trajectory Planning Against Undetectable Spoofing Attacks

This paper studies, for the first time, the trajectory planning problem in adversarial environments, where the objective is to design the trajectory of a robot to reach a desired final state despite the unknown and arbitrary action of an attacker. In particular, we consider a robot moving in a two-dimensional space and equipped with two sensors, namely, a Global Navigation Satellite System (GNSS) sensor and a Radio Signal Strength Indicator (RSSI) sensor. The attacker can arbitrarily spoof the readings of the GNSS sensor and the robot control input so as to maximally deviate his trajectory from the nominal precomputed path. We derive explicit and constructive conditions for the existence of undetectable attacks, through which the attacker deviates the robot trajectory in a stealthy way. Conversely, we characterize the existence of secure trajectories, which guarantee that the robot either moves along the nominal trajectory or that the attack remains detectable. We show that secure trajectories can only exist between a subset of states, and provide a numerical mechanism to compute them. We illustrate our findings through several numerical studies, and discuss that our methods are applicable to different models of robot dynamics, including unicycles. More generally, our results show how control design affects security in systems with nonlinear dynamics.Comment: Accepted for publication in Automatic

The Observability Radius of Networks

This paper studies the observability radius of network systems, which measures the robustness of a network to perturbations of the edges. We consider linear networks, where the dynamics are described by a weighted adjacency matrix, and dedicated sensors are positioned at a subset of nodes. We allow for perturbations of certain edge weights, with the objective of preventing observability of some modes of the network dynamics. To comply with the network setting, our work considers perturbations with a desired sparsity structure, thus extending the classic literature on the observability radius of linear systems. The paper proposes two sets of results. First, we propose an optimization framework to determine a perturbation with smallest Frobenius norm that renders a desired mode unobservable from the existing sensor nodes. Second, we study the expected observability radius of networks with given structure and random edge weights. We provide fundamental robustness bounds dependent on the connectivity properties of the network and we analytically characterize optimal perturbations of line and star networks, showing that line networks are inherently more robust than star networks.Comment: 8 pages, 3 figure

Charm production study in p-p and Pb-Pb collisions at the LHC with ALICE

The ALICE experiment at the LHC will study proton-proton and heavy-ion collisions with the aim of investigating the properties of the high-density state of strongly interacting matter, expected to be produced in central Pb-Pb collisions. Open charm mesons are expected to be a powerful probe to investigate this deconfined state of the medium and they will be studied extensively in ALICE. Open charm measurements in p-p collisions is fundamental as a baseline for the interpretation of Pb-Pb results and in order to calculate the charm cross section in a new energy window

Café orgânico: do cultivo à xícara

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Comunicação e Expressão. Jornalismo.Grande reportagem que mostra a filosofia de vida e as motivações dos produtopres de café orgânico, explicando o que é este produto, por que está sendo produzido, seu diferencial, dificuldades, vantagens, desvantagens. Para tal é contada a história de produtores da região de Machado e Poço Fundo na região de Minas Gerais que cultivam café orgânico e/ou voltaram à produção do convencional e, também, a de uma pioneira na região de Franca (SP