1,721,002 research outputs found
Tecniche di Intelligenza Artificiale Applicate alla Regolazione della Velocità di una Galleria del Vento
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CHAPTER 5 - Biomass combustion and chemical looping for carbon capture and storage
No full textAccording to a general definition biomass may be considered as animal and plant resources and the wastes deriving from their treatment, which could be used, directly or after a pretreatment as a source of energy. It is therefore a resource directly or indirectly resulting from the photosynthesis process, represented by the following equation (Klass, 1998):
Living plant + CO2 + H2O + Sunlight Chlorophyll−→ (CHmOn) + O2 − 480 kJ/mol For every mole of CO2 absorbed 1 mole of oxygen is released. Zhu et al. (2008) have shown that the maximum conversion efficiency of solar energy to biomass is 4.6% for C3 photosynthesis at 30◦C and today’s 380 ppm atmospheric concentration of CO2, while C4 plants have an efficiency of about 6%. Losses are distributed thus: loss by reflectance of photo-synthetically active light (4.9% for example); loss in rapid relaxation of higher excited states of chlorophyll (6.6% for example); loss between the reaction center and carbohydrate synthesis (24.6% for C3 plants and 28.7% for C4 plants, for example); loss due to photorespiration (around 6.1% for C3 plants and 0% for C4 plants); loss due to respiration (1.9% for C3 plants and 2.5% for C4 plants). Figure 5.1 shows the minimum energy losses calculated for 1000 kJ of incident solar radiation
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Model-based global and local motion estimation for videoconference sequences
No full textIn this work, we present an algorithm for face 3-D motion estimation in videoconference sequences. The algorithm is able to estimate both the position of the face as an object in 3-D space (global motion) and the movements of portions of the face, like the mouth or the eyebrows (local motion). The algorithm uses a modified version of the standard 3-D face model CANDIDE. We present various techniques to increase robustness of the global motion estimation which is based on feature tracking and an extended Kalman filter. Global motion estimation is used as a starting point for local motion detection in the mouth and eyebrow areas. To this purpose, synthetic images of these areas (templates),are generated with texture mapping techniques, and then compared to the corresponding regions in the current frame. A set of parameters, called action unit vectors (AUVs) influences the shape of the synthetic mouth and eyebrows. The optimal AUV values are determined via a gradient-based minimization procedure of the error energy between the templates and the actual face areas. The proposed scheme is robust and was tested with success on sequences of many hundreds of frames
Micro-cogenerazione da biomassa con tecnologia di pirolisi
Full text linkIl lavoro sintetizza le attività di ricerca e sviluppo in corso presso l’Università di Perugia sull’impiego del processo di pirolisi per la conversione energetica di biomasse. Viene descritta la tecnologia IPRP (Integrated Pyrolysis Regenerated Plant), originalmente proposta dagli autori che prevede un pirolizzatore a tamburo rotante associato ad una microturbina a gas. Successivamente si descrive l’attività di modellazione numerica dell’impianto per ottimizzare i parametri di funzionamento in funzione della taglia, e viene illustrato il tamburo rotante da laboratorio progettato e realizzato interamente presso il Dipartimento di Ingegneria Industriale dell’Università di Perugia. Si descrive infine la progettazione e realizzazione di un impianto pilota IPRP da 80 kWel, completo di microturbina, cofinanziato dalla Regione Umbria, costruito ed attualmente in fase di collaudo presso la sede di Terni. Dai risultati della ricerca è stata costituita nel 2005 la società di spin-off accademico denominata BIO-NET-Biomasse e Nuove Tecnologie Srl per la commercializzazione della tecnologia IPRP
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