1,691 research outputs found

    Rician MIMO Channel- and Jamming-Aware Decision Fusion

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    In this manuscript we study channel-aware decision fusion (DF) in a wireless sensor network (WSN) where: (i) the sensors transmit their decisions simultaneously for spectral efficiency purposes and the DF center (DFC) is equipped with multiple antennas; (ii) each sensor-DFC channel is described via a Rician model. As opposed to the existing literature, in order to account for stringent energy constraints in the WSN, only statistical channel information is assumed for the non-line-of sight (scattered) fading terms. For such a scenario, sub-optimal fusion rules are developed in order to deal with the exponential complexity of the likelihood ratio test (LRT) and impractical (complete) system knowledge. Furthermore, the considered model is extended to the case of (partially unknown) jamming-originated interference. Then the obtained fusion rules are modified with the use of composite hypothesis testing framework and generalized LRT. Coincidence and statistical equivalence among them are also investigated under some relevant simplified scenarios. Numerical results compare the proposed rules and highlight their jammingsuppression capability.Comment: Accepted in IEEE Transactions on Signal Processing 201

    Emotion Regulation and Parental Bonding in Families of Adolescents With Internalizing and Externalizing Symptoms

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    Parental bonding and emotional regulation, while important to explain difficulties that may arise in child development, have mainly been studied at an individual level. The present study aims to examine alexithymia and parental bonding in families of adolescents with psychiatric disorders through different generations. The sample included a total of 102 adolescent patients with psychiatric disorders and their parents. In order to take a family level approach, a Latent Class Analysis was used to identify the latent relationships among alexithymia (Toronto Alexithymia Scale), perceived parental bonding (Parental Bonding Instrument) and the presence of adolescent internalizing or externalizing psychiatric symptoms (Youth Self-Report). Families of internalizing and externalizing adolescents present different and specific patterns of emotional regulation and parenting. High levels of adolescent alexithymia, along with a neglectful parenting style perceived by the adolescent and the father as well, characterized the families of patients with internalizing symptoms. On the other hand, in the families with externalizing adolescents, it was mainly the mother to remember an affectionless control parental style. These results suggest the existence of an intergenerational transmission of specific parental bonding, which may influence the emotional regulation and therefore the manifestation of psychiatric symptoms

    Model Order Selection Rules For Covariance Structure Classification

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    The adaptive classification of the interference covariance matrix structure for radar signal processing applications is addressed in this paper. This represents a key issue because many detection architectures are synthesized assuming a specific covariance structure which may not necessarily coincide with the actual one due to the joint action of the system and environment uncertainties. The considered classification problem is cast in terms of a multiple hypotheses test with some nested alternatives and the theory of Model Order Selection (MOS) is exploited to devise suitable decision rules. Several MOS techniques, such as the Akaike, Takeuchi, and Bayesian information criteria are adopted and the corresponding merits and drawbacks are discussed. At the analysis stage, illustrating examples for the probability of correct model selection are presented showing the effectiveness of the proposed rules

    Spin geometry of the rational noncommutative torus

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    We discuss the structure of topologically non-trivial almost-commutative manifold for spectral triples realized on the algebra of smooth functions on the noncommutative torus with rational parameter. This is done by showing isomorphisms with a spectral triple on the algebra of sections of certain bundle of algebras, and with a spectral triple on a certain invariant subalgebra of the product algebra. The isomorphisms intertwine also the grading and real structure. This holds for all four inequivalent spin structures, which are explicitly constructed in terms of double coverings of the noncommutative torus (with arbitrary real parameter). These results are extended also to a class of curved (non flat)spectral triples, obtained as a perturbation of the standard one by eight central elements

    Headache disorders as risk factors for sleep disturbances in school aged children.

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    Several epidemiological studies have shown the presence of comorbidity between various types of sleep disorders and different headache subtypes. Migraine without aura is a sensitive risk factor for disorders of initiating and maintaining sleep (odds ratio (OR) 8.2500), and chronic tension-type headache for sleep breathing disorders (OR 15.231), but headache disorder is a cumulative risk factor for disorders of excessive somnolence (OR 15.061). This result has not been reported in the clinical literature. © Springer-Verlag Italia 2005

    The black hole X-ray binary MAXI J1348−-630 in quiescence

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    The properties of the disk/jet coupling in quiescent black hole low mass X-ray binaries (BH LMXBs) are still largely unknown. In this paper we present the first quasi-simultaneous radio and X-ray detection in quiescence of the BH LMXB MAXI J1348−-630, which is known to display a hybrid disk/jet connection that depends on the accretion rate. We performed deep X-ray and radio observations using the Chandra X-ray Observatory and the Australia Telescope Compact Array. MAXI J1348−-630 is detected for the first time in quiescence at an X-ray luminosity LX=(7.5±2.9)×1030(D/2.2 kpc)2L_{\rm X} = (7.5 \pm 2.9) \times 10^{30} (D/2.2 \ {\rm kpc})^2 erg s−1^{-1}: one of the lowest X-ray luminosities observed for a quiescent BH LMXB, possibly implying a short orbital period for the system. MAXI J1348−-630 is also detected in radio at LR=(4.3±0.9)×1026(D/2.2 kpc)2L_{\rm R} = (4.3 \pm 0.9) \times 10^{26} (D/2.2 \ {\rm kpc})^2 erg s−1^{-1}. These detections allow us to constrain the location of MAXI J1348−-630 on the radio/X-ray diagram in quiescence, finding that the source belongs to the standard (radio-loud) track in this phase. This provides a strong confirmation that hybrid-correlation sources follow the standard track at low luminosities and down to quiescence, thus improving our knowledge of the disk/jet connection in BH LMXBs.Comment: 5 pages, 3 figures. Accepted for publication in MNRAS Letter

    A Method for Simple and Precise Measurements of Kinetics of Reactions between SiC and Molten Al

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    Reinforced aluminum is generally fabricated by liquid metal infiltration. The reinforcement degradation produced by molten matrix is the major problem to be considered. The relationship between conversion and thermal exposure time is an important information. In the present paper a method for measuring the conversion by weight determinations is proposed

    Wettability of Copper Coated Carbon Fibers

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    The wetting kinetics of a solid surface by a molten metal decrease with increase of its roughness. The topography of the growing copper coating, produced on carbon fiber surface by electroplating from a sulphat bath, has been studied by scanning electron microscopy. The smoothes surface is produced after 200÷300 milliampere-hour of plating

    Growth and remodeling in highly stressed solid tumors

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    Growing biological media develop residual stresses to make compatible elastic and inelastic growth-induced deformations, which in turn remodel the tissue properties modifying the actual elastic moduli and transforming an initially isotropic and homogeneous material into a spatially inhomogeneous and anisotropic one. This process is crucial in solid tumor growth mechanobiology, the residual stresses directly influencing tumor aggressiveness, nutrients walkway, necrosis and angiogenesis. With this in mind, we here analyze the problem of a hyperelastic sphere undergoing finite heterogeneous growth, in cases of different boundary conditions and spherical symmetry. By following an analytical approach, we obtain the explicit expression of the tangent elasticity tensor at any point of the material body as a function of the prescribed growth, by involving a small-on-large procedure and exploiting exact solutions for layered media. The results allowed to gain several new insights into how growth-guided mechanical stresses and remodeling processes can influence the solid tumor development. In particular, we highlight that— under hypotheses consistent with mechanical and physiological conditions—auxetic (negative Poisson ratio) transformations of the elastic response of selected growing mass districts could occur and contribute to explain some not yet completely understood phenomena associated to solid tumors. The general approach proposed in the present work could be also helpfully employed to conceive composite materials where ad hoc pre-stress distributions can be designed to obtain auxetic or other selected mechanical properties
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