6,691 research outputs found

    The discrimination problem for two ground states or two thermal states of the quantum Ising model

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    We address the one-dimensional quantum Ising model as an example of system exhibiting criticality and study in some details the discrimination problem for pairs of states corresponding to different values of the coupling constant. We evaluate the error probability for single-copy discrimination, the Chernoff bound for nn-copy discrimination in the asymptotic limit, and the Chernoff metric for the discrimination of infinitesimally close states. We point out scaling properties of the above quantities, and derive the external field optimizing state discrimination for short chains as well as in the thermodynamical limit, thus assessing criticality as a resource for quantum discrimination in many-body systems.Comment: revised version, title changed, 4 fig

    \u201c\u2018Nel suo No sempiterno a tutti i programmi della Joie.\u2019 Causa ideale e mito di Antigone nel Cardillo addolorato di Anna Maria Ortese\u201d.

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    L'intento di questo saggio \ue8 quello di fornire alcuni spunti interpretativi per il romanzo Il cardil-lo addolorato (1993) di Anna Maria Ortese, sulla scorta del modello psicanalitico lacaniano e di un confronto con il mito di Antigone. Il primo capitolo consiste in una breve introduzione alla complessit\ue0 esegetica dell'opera e al tema dell'enigma in senso fattuale e semantico. Successi-vamente si discute la posizione della protagonista Elmina quale oggetto del desiderio dei tre signori di Liegi e portavoce del discorso isterico. Infine, a partire da un confronto con possibili fonti testuali, si avanza l'ipotesi di una presenza sotterranea del mito di Antigone, per cui El-mina sarebbe una figura del desiderio utopico: la sua devozione per Hieronymus K\ue4ppchen assume le sembianze di un'intransigenza etica che evoca in tono minore ma non meno doloroso il dramma di Antigone

    Towards Efficient Full Pose Omnidirectionality with Overactuated MAVs

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    Omnidirectional MAVs are a growing field, with demonstrated advantages for aerial interaction and uninhibited observation. While systems with complete pose omnidirectionality and high hover efficiency have been developed independently, a robust system that combines the two has not been demonstrated to date. This paper presents VoliroX: a novel omnidirectional vehicle that can exert a wrench in any orientation while maintaining efficient flight configurations. The system design is presented, and a 6 DOF geometric control that is robust to singularities. Flight experiments further demonstrate and verify its capabilities.Comment: 10 pages, 6 figures, ISER 2018 conference submissio

    Pablo Neruda. Cartas a Laura. Cultura HispĂĄnica, Madrid, 1978

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    A computational view of the brain plasticity at rest

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    Even when the human brain is at rest, its activity continues to change spontaneously. We know very little about the neuroanatomical structures and the biological mechanisms involved. Such knowledge is important for understanding human perception and brain changes, both in healthy people and in disease. Therefore, the overall aim of my research was to expand our understanding of the biological and computational mechanisms underlying the plasticity of spontaneous human brain activity. I specifically focused my research on developing methods to analyze small-scale interactions between visual brain regions and large-scale interactions at the level of brain networks. A commonly used tool for brain research in humans is functional magnetic resonance imaging. This allows researchers to register brain activity in a non-invasive way and in a relatively short time, also in people who are in a resting state (rs-fMRI). Based on the measured activity, the functional relationships between different brain regions can be mapped without the need to present a stimulus. Another advantage is that rs-fMRI requires very little effort from the participant. Together, this makes rs-fMRI very useful to investigate the consequences of neuro-ophthalmic diseases on the brain, even at an advanced stage (eg in case of glaucoma in near-blindness). Therefore, in my dissertation, I focused on the use of rs-fMRI. In my dissertation, I demonstrate the fundamental and clinical relevance of measuring changes in spontaneous brain activity using rs-fMRI. The new methods that I have developed make it possible to investigate small-scale and large-scale functional connections in the brain. Moreover, they make it easier to apply rs-fMRI clinically in both the early and later stages of a disease. My methods can help future studies to increase our understanding of the functional connections of the healthy visual cortex and changes therein due to disease. They enable researchers to translate their knowledge about how the brain works into new, sophisticated diagnostic applications and therapeutic interventions