Quantum information protocols in complex entangled networks

Quantum entangled networks represent essential tools for Quantum Communication, i.e. the exchange of Quantum Information between parties. This work consists in the theoretical study of continuous variables (CV) entangled networks - which can be deterministically generated via multimode squeezed light - with complex topology. In particular we investigate CV complex quantum networks properties for quantum communication protocols. We focused on the role played by the topology in the implementation and the optimization of given characteristics of our entangled resource that are useful for a specific quantum communication task, i.e. the creation of an entanglement link between two arbitrary nodes of the resource we are provided with. We implemented an analytical procedure for the generation of entangled complex networks, their optimization and their manipulation via global linear optics operations. We also developed a numerical procedure, based on an evolutionary algorithm, for manipulating entanglement connections via local linear optics operations. Finally, we analyzed the re-shaping of our entangled resource via homodyne measurements

Young Children’s cliques : a study on processes of peer acceptance and cliques aggregation

A considerable amount of research has examined the link between children’s peer acceptance, which refers to the degree of likability within the peer group, social functioning and emotional wellbeing, at a same age and in a long term perspective, pointing out to the contribution of peer acceptance for mental wellbeing. Our study proposes a sociometric methodology that, differently from many studies focused on individual classifications of social status, moves to the analysis of affiliative social networks within the class group. This study describes how individual factors such as socio-emotional competence, temperament, and linguistic skills are related to positive reciprocated nominations (=RNs) and examines the cliques generated by reciprocal nominations according to similarities (socio-emotional competence, temperament and linguistic skills) among cliques’ members. Eighty-four preschool children (M age = 62.5 months) were recruited. The Sociometric Interview to assess RNs and the Peabody Picture Vocabulary Test - Revised (PPVT-R; Dunn & Dunn, 1981) to assess receptive language were administered; the Social Competence and Behaviour Evaluation Short Form questionnaire (SCBE-30; LaFreniere & Dumas, 1996) and the Quit Temperament Scale (Axia, 2002) were filled in by the teachers. Results showed that children with higher RNs presented higher scores in social orientation, positive emotionality, motor activity, linguistic skills and social competence (trend), and exhibited lower anxietywithdrawal. The analysis of cliques revealed that children preferred playmates with similar features: social competence, anger-aggression (trend), social orientation, positive emotionality, inhibition to novelty, attention, motor activity (trend) and linguistic skills. These findings provide insights about processes of peer affiliation, highlighting the role of socio-emotional functioning and linguistic skills.peer-reviewe

Continuous variables graph states shaped as complex networks: optimization and manipulation

Complex networks structures have been extensively used for describing complex natural and technological systems, like the Internet or social networks. More recently complex network theory has been applied to quantum systems, where complex network topologies may emerge in multiparty quantum states and quantum algorithms have been studied in complex graph structures. In this work we study multimode Continuous Variables entangled states, named cluster states, where the entanglement structure is arranged in typical real-world complex networks shapes. Cluster states are a resource for measurement-based quantum information protocols, where the quality of a cluster is assessed in term of the minimal amount of noise it introduces in the computation. We study optimal graph states that can be obtained with experimentally realistic quantum resources, when optimized via analytical procedure. We show that denser and regular graphs allow for better optimization. In the spirit of quantum routing we also show the reshaping of entanglement connections in small networks via linear optics operations based on numerical optimization.Comment: 10 pages, 7 figure

Integrating reliability and resilience to support microgrid design

Quantifying the potential benefits of microgrids in the design phase can support the transition of passive distribution networks into microgrids. At current, reliability and resilience are the main drivers for this transition. Therefore, this paper presents a mathematical optimization model to support the retrofitting of distribution networks into microgrids integrating techno-economic, resilience and reliability objectives. Storage and distributed generation are optionally installed to complement renewable generation, enabling the microgrid to supply priority demands during stochastic islanding events with uncertain duration. For a comprehensive quantification and optimization of microgrid resilience and reliability, islanding due to external events is combined with a detailed model of internal faults. Minimizing the interruption costs yields optimal capacities and placements of distributed energy resources and new lines for reconfiguration. The proposed method produces microgrid designs with up to 95% reliability and resilience gain and moderate cost increase in two benchmark distribution networks using data from the US Department of Energy. The developed methodology is scalable to large networks owing to the tailored Column-and-Constraint-Generation approach

Optimizing protections against cascades in network systems: A modified binary differential evolution algorithm

International audienceThis paper addresses the optimization of protection strategies in critical infrastructures within a complex network systems perspective. The focus is on cascading failures triggered by the intentional removal of a single network component. Three different protection strategies are proposed that minimize the consequences of cascading failures on the entire system, on predetermined areas or on both scales of protective intervention in a multi-objective optimization framework. We optimize the three protection strategies by devising a modified binary differential evolution scheme that overcomes the combinatorial complexity of this optimization problem. We exemplify our methodology with reference to the topology of an electricity infrastructure, i.e. the 380 kV Italian power transmission network. We only focus on the structure of this network as a test case for the suggested protection strategies, with no further reference on its physical and electrical properties

Misura della risoluzione temporale del sistema a Tempo di Volo (TOF) di ALICE a (sNN)=5.02\sqrt(s_NN)=5.02 TeV

Il QGP è un particolare stato della materia che si produce in collisioni di ioni pesanti ad alte energie e la sua osservazione avviene indirettamente tramite lo studio delle particelle prodotte in seguito alla sua adronizzazione. L'analisi degli stati finali prodotti nelle collisioni si basa su un complesso processo di ricostruzione di tracce, vertici primari e secondari e di identificazione delle particelle; pertanto è necessario stimare accuratamente ed eventualmente minimizzare le incertezze di misura al fine di condurre un'analisi corretta del fenomeno. In questa tesi si presenta uno studio rivolto alla determinazione diretta della risoluzione $\sigma_{TOF}$ del sistema a Tempo di Volo (TOF) dell'esperimento ALICE presso il Large Hadron Collider del CERN. L'analisi, basata su dati da collisioni Pb-Pb a $\sqrt{s_{NN}}=5.02 TeV$, ha messo in evidenza un significativo miglioramento della risoluzione $\sigma_{TOF}$, ora valutata migliore di 70 ps

Eye-Movements in a Text Reading Task: A Comparison of Preterm Children, Children with Dyslexia and Typical Readers

Preterm birth is associated with weaknesses in reading skills that are usually less severe than those of children with dyslexia. To understand the characteristics of reading processes in preterm children, we adopted a cross-population and multi-modal approach comparing eye movements in reading tasks among three groups: children with preterm birth, children with a diagnosis of dyslexia, and children with typical development. The study involved 78 participants (10.5 years). Eye movements (number and duration of fixations, amplitude and number of saccades, number of regressions) were recorded during the silent reading of two texts; cognitive and reading standardized tasks were also administered. Children with dyslexia had more fixations and more frequent and smaller saccades compared to the preterm group and children with typical development. They also showed more regressions compared to the control group. Preterm children showed shorter fixations compared to the other groups. Cognitive and reading standardized tasks confirmed severe delays in reading in children with dyslexia and some weaknesses in text reading speed and comprehension in preterm children. These results are discussed with reference to candidate mechanisms that underlie reading processes in preterm children and considering possible implications for research

Linguistic features in children born very preterm at preschool age

6noAIM This cross-sectional study focused on the effect of very preterm (VPT) birth on language development by analysing phonological, lexical, grammatical, and pragmatic skills and assessing the role of cognitive and memory skills. METHOD Sixty children (29 males, 31 females) born VPT (<32wks) aged 5 years were compared with 60 children with typical development. The linguistic assessment was performed by administering a battery of Italian tests for the evaluation of language; cognitive and memory skills were assessed by Raven’s coloured progressive matrices and digit span subtest (Wechsler Intelligence Scale for Children [WISC-III]). RESULTS Children born VPT showed delays in lexical (comprehension: z-score difference 1.18; 95% confidence interval [CI] 1.60 to 0.77; naming: 0.88; 95% CI 1.19 to 0.58) and pragmatic skills (comprehension: 0.76; 95% CI 1.02 to 0.49; narrative production: 0.47; 95% CI 0.72 to 0.23). Delays in phonology and grammar were less diffuse, involving productive skills (1.09; 95% CI 1.64 to 0.54; 0.48; 95% CI 0.85 to 0.12, respectively), and were dependent by cognitive and memory skills. Lexical delays were more specific. INTERPRETATION The linguistic profile of children born preterm is characterized by some abilities more impaired than others. This highlights the need of a linguistic assessment at the end of preschool age in order to plan a focused intervention aimed at improving lexical and pragmatic skillsopenopenGuarini, Annalisa; Marini, Andrea; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, AlessandraGuarini, Annalisa; Marini, Andrea; Savini, Silvia; Alessandroni, Rosina; Faldella, Giacomo; Sansavini, Alessandr

Analysis of the safety efficiency of a road network: a real case study

In this paper, recently introduced topological measures of interconnection and efficiency of network systems are applied to the safety analysis of the road transport system of the Province of Piacenza in Italy. The vulnerability of the network is evaluated with respect to the loss of a road link, e.g. due to a car accident, road work or other jamming occurrences. Eventually, the improvement in the global and local safety indicators following the implementation of a road development plan is evaluated