256 research outputs found
Il greco a Ferrara
No full textIl greco a Ferrara
Nell'ambito del DOTTORATO DI RICERCA IN MODELLI, LINGUAGGI, TRADIZIONI DELLA CULTURA OCCIDENTALE si terranno le seguenti conferenze e seminari, organizzate da Angela Maria Andrisano, docente di Filologia classica presso la Facoltà di Lettere e Filosofia:
O. Montanari (Università di Bologna), La tipologia del mostro, da Omero al dramma satiresco". Introduce Angela M.Andrisano (9 febbraio, ore 17 Biblioteca Ariostea)
M.G.Ciani (Univ. di Padova, ), G.Avezzù (Univ. di Verona),R. Tosi (Università di Bologna) presentano il volume di A. Rodighiero, La morte di Eracle. Introduce Angela M.Andrisano (1 marzo, ore 17 Biblioteca Ariostea)
X. Riu (Università di Barcellona)- V. Tammaro (Università di Bologna) , L'attacco personale nella commedia classica e nella tradizione giambica. Introduce A.M.Andrisano (Università di Ferrara) (10 marzo ore 15 Biblioteca Ariostea)
P.Pinotti, L'esemplificazione omerica nei Remedia Amoris. Introduce Angela M.Andrisano (16 marzo, ore 15 Biblioteca Ariostea)
Analytical outage evaluation of TDMA local radio systems with coding and diversity
No full textA completely analytical approach is presented in order to evaluate outage probability of TDMA (time-division multiple access) local radio systems using coding and diversity to combat frequency selective fading. First, starting from a multiray model for multipath propagation, performance sensitivity is tested by suitably simplifying the channel model. An analytical expression is obtained of the probability that BER may exceed a fixed value in the presence of a simplified channel model. A suitable upper bound formulation is given to express the same probability in the presence of coding and diversity techniques. Finally, some application examples are proposed both with reference to slow frequency hopping and space diversity system
Performance evaluation method and comparison of local radio systems on selective fading channels
No full textNatural Frequencies of Triple-Walled Carbon Nanotubes
No full textIn this paper, the linear vibrations of Triple-Walled Carbon Nanotubes (TWNTs) are analysed. A multiple elastic shell model is considered. The shell dynamics is studied in the framework of the Sanders-Koiter shell theory. The van der Waals (vdW) interaction between two layers of the TWNT is modelled by a radius-dependent function. The circular cylindrical shell deformation is described in terms of longitudinal, circumferential and radial displacements. Simply supported, clamped and free boundary conditions are considered. The three displacement fields are expanded by means of a double mixed series based on Chebyshev orthogonal polynomials for the longitudinal variable and harmonic functions for the circumferential variable. The Rayleigh-Ritz method is applied to obtain approximate natural frequencies and mode shapes. The present model is validated in linear field by means of data derived from the literature. This study is focused on determining the effect of the geometry and boundary conditions on the natural frequencies of TWNTs
Un modello a più gradi di libertà per l'analisi dinamica di trasmissioni con croce di Malta
No full textNonlinear Power Amplifier Effects on the Performance of CPFSK Systems
No full textCPFSK signals with rectangular modulation pulse shaping are tested here in a transmission system including a nonlinear high-power amplifier (HPA), working at saturation. The effects of filtering followed by amplifying on power spectrum spreading of the transmitted signal and on error probability are determined. The results obtained show that, unlike other modulation systems (PSK, offset PSK, MSK), in the CPFSK case the power spectrum at HPA output can be efficiently controlled by means of filtering at the intermediate frequency (IF), if the duty-cycle τ/T of modulation pulses and the maximum angular frequency deviation ωd are suitably chosen. Moreover, by considering the transmission of a single radio frequency (RF) channel, they show that the nonlinear behavior of the transmitter has very little influence on error probability for all the ωd values of practical interest, other conditions being fixed
New Hip Joint Simulator Model For Biomaterials Tribological Analysis
No full textABSTRACT: Using the traditional tribological wear tests it is not possible to completely verify the real final performance of a combination of biomaterials and hip joint prosthesis geometry.
Thus, for such a complex bearing combination, a more physiologically representative implants wear test is required; this can only be provided using complex mechanical simulators capable to reproduce, as close as possible, the real in vivo physiological loading and motion replacement working conditions.
In this paper a new model of hip joint simulator will be presented, developed in order to test different kinds of hip joint prosthetic implant materials under the in vivo working conditions. Unlike other existing multi-axis hip joint simulators, whose performance were initially accurately studied and classified in terms of transmitted force and reproduced motion accuracy and versatility of use, this hip joint simulator has been studied to stand out the state of the art for its superior accuracy in completely reproducing the physiological condition of time dependent loading and three-dimensional mutually articulating bearing surfaces, and also simulating the physiological environment
Performance Improvement through Diversity Reception for Bluetooth on the Presence of Interference
No full textIn this work, we propose an analytical framework to derive the performance of Bluetooth (BT) in the presence of an IEEE802.11g interferer. In particular, aiming at improving the performance of BT in the presence of interference still maintaining low the complexity, we propose a selection diversity scheme at the receiver side of the BT system and we exploit the spatial diversity to improve the coexistence between different systems sharing resources. We firstly analytically derive the BT performance in terms of mean block error probability and mean packet error probability averaged over Rayleigh fading, then we extend the analysis to the evaluation of the packet error outage, an important figure of merit when real time scenarios are considered. We show that a not negligible improvement for the coexistence issue of the involved systems can be achieved
Up-link analytical outage evaluation for slow frequency hopping mobile radio systems
No full textIn a shadowing-free environment, the improvement introduced by slow frequency hopping (SFH) on a TDMA-based mobile radio system can be taken into account by properly re-defining the minimum carrier-to-interference protection ratio. This protection ratio, with SFH, is dependent on the transmission system, channel model, traffic and frequency reuse parameters. The approach is used in order to analytically investigate the up-link capacity of a SFH mobile radio system, by taking into account a complete scenario, i.e. shadowing, fast fading, power control, antenna diversity, discontinuous transmission and forward error correction (FEC) with non-ideal interleaving and sectorization
Millimeter waves for short-range multimedia communication systems
No full textA framework for the performance characterization of short-range communications systems is developed with the intention of investigating the feasibility of new multimedia wireless services at millimeter waves (MMWs). Both narrow- and wide-band systems are considered for mobile and/or fixed users. This paper aims at defining and evaluating proper metrics to characterize the service quality for the user and jointly takes the propagation characteristics, the transmission techniques, and the multiple access protocols into account. The definition of service-oriented metrics is emphasized. Three different real scenarios operating at MMW are investigated with a unified perspective: intelligent transport systems, wide-band local-area networks, and local multipoint distribution systems for interactive video services. The role played by the MMW band in the development of these services is discussed. In each scenario, accurate propagation analysis is carried out and suitable countermeasure techniques are pointed out in order to join suitable service-quality levels. The methodology considered is based on both analytical and semianalytical tools for performance evaluatio
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