1,721,008 research outputs found
Design and analysis of activation strategies for adaptive notch filters to suppress GNSS jamming
No full textAdaptive notch filters (ANFs) have been widely investigated in literature for their low complexity and good performance, and used in many signal processing applications. More recently, they have been proven to be an effective solution against jamming interferences, considered more than ever a real threat to Global Navigation Satellite System signals. This article focuses on a specific family of ANF, where the adaptation algorithm is implemented as a frequency-lock-loop (FLL), namely FLL-equivalent ANFs. It presents the theoretical derivation of two detection approaches, namely power ratio-based and gradient-based, in charge of activating/deactivating such kind of filters. Both the theoretical and statistical analysis in case of swept-frequency jamming signals are provided. The performance evaluation for several interference-to-noise ratio conditions shows a tradeoff between the two solutions, with a slight advantage of the power ratio-based strategy. The results achieved in simulation clearly demonstrate that the proposed activation strategies can be combined with ANFs and that they can be effectively adopted for the mitigation of jamming signals
Optimized Cosine Modulated Q2PSK
No full textIn this paper, we present a novel cosine modulated Q2PSK modulation scheme that provides useful spectral separation between baseband pulse
Integration of a HAP Within a Terrestrial UMTS Network: Interference Analysis and Cell Dimensioning
No full textComplessità della performance e autoriflessione. Jacques Derrida attore di se stesso
No full textRiflessioni sui rapporti tra teatro e filosofia, in particolare sul concetto di performance applicata al caso di un filosofo che recita la parte di se stesso in un documentario filmato. Automatismo (l’attore che impara a fingere; tale è la sua ‘verità’ scenica) e la costruzione del discorso filosofico
Integrated services from high-altitude platforms: a flexible communication system
No full textIn this article the provision of integrated services from high-altitude platforms (HAPs) is discussed, and a flexible communication system for HAP-based communications is identified and analyzed, with particular attention to the delivery of broadband services from HAPs to highspeed trains. The high coding gain required by the proposed scenario is achieved through adaptive concatenated coding schemes, while smart antennas operating with adaptive beamforming algorithms are employed at the ground stations. The simulated system performance based on a multi-antenna model of the stratospheric channel is reported, and the use of HAPs in synergy with terrestrial and satellite systems is discusse
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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