1,720,960 research outputs found
D'Angelo Simone
No full textSi indaga la produzione artistica D'Angelo Simone, orafo e argentiere nel XIX secolo in SiciliaWe investigate the artistic production of D'Angelo Simone, goldsmith and silversmith in the nineteenth century in Sicil
Advanced Analysis of WMA Asphalt Mixtures to Assess the Technology Readiness Level in Motorway Pavement Applications
No full textIn risposta alle preoccupazioni globali sull'inquinamento ambientale e il risparmio energetico, il settore dei materiali stradali sta esplorando alternative sostenibili al tradizionale conglomerato bituminoso. Questa tesi di dottorato analizza le miscele bituminose tiepide per valutarne l'idoneità nelle applicazioni autostradali. Il conglomerato tiepido offre una soluzione ecologica, soprattutto se combinato con alte percentuali di fresato o polverino di gomma da pneumatici fuori uso (PFU). Questi metodi riducono il consumo di energia, l'uso di materie prime, gli impatti ambientali e migliorano le condizioni di lavoro. La Ricerca presso il Laboratorio Stradale e Trasporti dell'Università Politecnica delle Marche ha coinvolto indagini in laboratorio, impianto e sul campo. Gli studi hanno ottimizzato le miscele tiepide con 25% di fresato per strati di usura drenante, 30% per strati di usura e 45% per strati di base, confermandone l'idoneità per la rete autostradale italiana. I risultati hanno dimostrato che queste miscele soddisfano i requisiti volumetrici e meccanici previsti dalle specifiche italiane, provando la loro fattibilità per una produzione su larga scala. Ulteriori indagini hanno esplorato miscele tiepide contenenti PFU per ottenere miscele semi-porose mirate a ridurre il rumore degli pneumatici. I test hanno dimostrato che le miscele tiepide con PFU raggiungono lavorabilità e prestazioni meccaniche comparabili alle miscele convenzionali. Le valutazioni superficiali hanno confermato un'adeguata resistenza allo spogliamento e aderenza dopo levigatura. Inoltre, è stata sviluppata una metodologia in cinque fasi per identificare additivi chimici ottimali per diminuire le temperature operative delle miscele bituminose. Questo processo ha incluso valutazioni della compatibilità chimica, viscosità, adesione, lavorabilità e resistenza, garantendo la selezione di additivi che migliorano la sostenibilità senza compromettere le prestazioni. La Ricerca ha anche valutato le prestazioni a lungo termine di bitumi da pavimentazioni realizzate con conglomerato bituminoso caldo e tiepido. Le analisi fisico-chimiche e reologiche hanno indicato che i bitumi da conglomerato tiepido presentavano una minore ossidazione e degradazione dei polimeri rispetto a quelli del conglomerato tradizionale, mantenendo proprietà superiori anche dopo cinque anni di servizio. I risultati promettenti sostengono l'adozione di queste tecnologie innovative nella produzione di conglomerato. Il Technology Readiness Level (TRL) è dimostrato da test di successo in ambienti operativi reali, evidenziando la maturità e prontezza per una vasta implementazione. Promuovendo pratiche di costruzione sostenibile e migliorando la durabilità e le prestazioni delle infrastrutture autostradali, questi progressi affrontano le attuali sfide ambientali rispettando i rigorosi standard tecnici.In response to global concerns about environmental pollution and energy conservation, the road materials sector is seeking sustainable alternatives to traditional Hot Mix Asphalt (HMA). This PhD thesis focuses on an advanced analysis of Warm Mix Asphalt (WMA) mixtures to evaluate their suitability for motorway applications. WMA offers an eco-friendly solution, particularly when combined with high percentages of Reclaimed Asphalt (RA) or Crumb Rubber (CR) derived from end-of-life tires (ELTs). These methods help reduce energy consumption, decrease the use of raw materials, mitigate environmental impacts, and improve working conditions. Research conducted at the Road and Transport Laboratory of the Marche Polytechnic University involved extensive laboratory, in-plant, and in-field investigations. Initial studies optimized WMA mixtures with 25% RA for open-graded wearing courses, 30% RA for dense-graded wearing courses, and 45% RA for base courses, confirming their suitability for the Italian Motorway Network. Experimental results demonstrated that these mixtures met the volumetric and mechanical requirements of Italian Motorway Technical Specifications, proving their feasibility for large-scale production. Further investigations explored combining WMA with CR from ELTs to create semi-porous asphalt mixtures aimed at reducing pavement noise. Laboratory tests showed that CR-enhanced WMA mixtures achieved workability and mechanical performance comparable to conventional mixtures. Surface property assessments confirmed adequate raveling resistance and maintained friction after polishing. Additionally, a five-step methodology was developed to identify optimal chemical additives for lowering the operational temperatures of asphalt mixtures. This process included evaluations of chemical compatibility, viscosity, adhesion, workability, and resistance, ensuring the selection of additives that enhance sustainability without compromising performance. The Research also assessed the long-term performance of bitumens from pavements constructed using both WMA and HMA technologies. Physicochemical and rheological analyses indicated that WMA bitumens exhibited reduced oxidation and polymer degradation compared to HMA, maintaining superior properties even after five years of service. The promising findings strongly support the widespread adoption of these innovative technologies in asphalt production. Their high Technology Readiness Level (TRL) is evidenced by successful tests in real operational environments, demonstrating their maturity and readiness for broad implementation. By promoting sustainable road construction practices and enhancing Motorway infrastructure durability and performance, these advancements significantly address current environmental challenges while meeting stringent technical standards
Efficient Development of Model-Based Controllers in PX4 Firmware: A Template-Based Customization Approach
Full text linkThis paper introduces a refined iteration of the PX4 autopilot firmware tailored to support developers in integrating bespoke control algorithms alongside the existing control framework. The proposed methodology employs a template-driven approach and introduces two novel control modules, thereby enabling users to harness all firmware functionalities within their custom modalities, including the QGroundControl interface, while retaining all the standard modules and compatibility with the QGroundControl interface. With its transparent and adaptable structure, the software framework presented herein lays a robust groundwork for implementing tailored and specialized solutions across diverse aerospace domains. As a practical demonstration, we apply the developed firmware to the domain of inspection and maintenance, wherein it incorporates an admittance controller and a model-based control algorithm for a tiltable drone equipped with a sensorized tool. The efficacy and versatility of the proposed approach are validated through simulations and empirical trials conducted across multiple aerial platforms. The produced code is released to the community
Semi-autonomous unmanned aerial manipulator teleoperation for push-and-slide inspection using parallel force/vision control
Full text linkPerforming inspection and maintenance tasks with aerial robots in complex industrial facilities require high levels of maneuverability and dexterity. As full autonomy still struggles to provide robust solutions due to limited adaptability and high development costs, this study explores the paradigm shift towards shared control teleoperation for tilting unmanned aerial manipulators (UAMs). The research initially focuses on integrating onboard camera measurements and interaction force feedback within a parallel force/vision controller for push-and-slide inspection tasks. The control loop lends itself to the development of a semi-autonomous operation architecture that enables a human operator to easily accomplish the task by means of a simple input device. The paper presents a user study evaluating task completion performance with human-in-the-loop control versus fully autonomous execution. Statistical analysis of 20 user experiences provides insights into the levels of autonomy necessary for effective task completion. Among the analyzed control modalities, statistically significant differences arise when the sliding feature is autonomous, denoting it as the most difficult to manually accomplish. The investigation is conducted within a simulated environment to ensure the safety of sensitive instruments and accommodate users with varying levels of expertise. By proposing shared control architectures, this research addresses the challenges of autonomous UAM operations in hazardous industrial environments, highlighting the benefits of human oversight and control in enhancing task efficiency and safety
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
