Study of Driving Factors in Preliminary Design of Autonomous Systems

A new approach to system design is proposed and evaluated through a series of analytical results and numerical simulationsope

Requirements for cabin crew medical examinations and assessments

The aim of the current study is to review current regulations relatively to medical requirements necessary to achieve suitability to fly of the cabin crew. There are three classes of flight crew medical standards and licensing. A first class medical certificate is required for all pilots who perform professional flights or skydiving instructors. A second class medical certificate is required only for persons who do not perform professional flights, skydiving activities or any other professional activity related to aircraft piloting (cabin crew, holders of Light Aircraft Pilot’s Licence - LAPL, remote pilot operators). Finally, a third class medical certificate is required for workers engaged in air traffic control

Impact of Illumination Correlated Color Temperature, Background Lightness, and Painting Color Content on Color Appearance and Appreciation of Paintings

© 2019, © 2019 Illuminating Engineering Society. Lighting design for art exhibitions has a significant impact on the enjoyment and understanding of the displayed artworks. In particular, the selection of the light sources and the design of the museum space affect the visitors' visual perceptions of the artworks and their color appearance. This project investigated some of the potential factors—the correlated color temperature (CCT) of the illumination, the overall color content of the painting and the lightness of its background—affecting a painting's color appearance and appreciation in a museum setting. The study involved a survey conducted in the laboratory with both naïve observers and lighting experts. The CCT of the lighting was found to be the main factor affecting the painting's appearance and the observers' overall preference for the lighting arrangements, whereas the overall hue content of the painting and the background lightness had a minor influence. Furthermore, it has been found that the perceived brightness increases along with the CCT. ispartof: LEUKOS vol:16 issue:1 pages:25-44 status: publishe

Microgenomic Analysis in Skeletal Muscle: Expression Signatures of Individual Fast and Slow Myofibers

BACKGROUND: Skeletal muscle is a complex, versatile tissue composed of a variety of functionally diverse fiber types. Although the biochemical, structural and functional properties of myofibers have been the subject of intense investigation for the last decades, understanding molecular processes regulating fiber type diversity is still complicated by the heterogeneity of cell types present in the whole muscle organ. METHODOLOGY/PRINCIPAL FINDINGS: We have produced a first catalogue of genes expressed in mouse slow-oxidative (type 1) and fast-glycolytic (type 2B) fibers through transcriptome analysis at the single fiber level (microgenomics). Individual fibers were obtained from murine soleus and EDL muscles and initially classified by myosin heavy chain isoform content. Gene expression profiling on high density DNA oligonucleotide microarrays showed that both qualitative and quantitative improvements were achieved, compared to results with standard muscle homogenate. First, myofiber profiles were virtually free from non-muscle transcriptional activity. Second, thousands of muscle-specific genes were identified, leading to a better definition of gene signatures in the two fiber types as well as the detection of metabolic and signaling pathways that are differentially activated in specific fiber types. Several regulatory proteins showed preferential expression in slow myofibers. Discriminant analysis revealed novel genes that could be useful for fiber type functional classification. CONCLUSIONS/SIGNIFICANCE: As gene expression analyses at the single fiber level significantly increased the resolution power, this innovative approach would allow a better understanding of the adaptive transcriptomic transitions occurring in myofibers under physiological and pathological condition

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

Design and Testing of Clustered Components For Modular Spacecraft Architectures

In recent years, the space industry has demonstrated a renewed interest in multi agent systems, from the deployment of large and mega constellations to the plans to test Federated and in orbit assembly concepts. Furthermore, as the CubeSat platform has become a de-facto standard able to support ambitious missions, the cost for multi agent systems has decreased significantly. The aim of this work is to study the benefits and drawbacks of large multi agent systems which might result from in-space assembly of numerous small autonomous spacecraft. The thesis is divided into two parts; in the first we focus on how to efficiently and reliably control large clusters of actuators spread across a modular assembly. We examine both classical centralized and decentralized methods to solve the allocation of tasks within the clusters and finally propose a novel method, for which we provide proof of convergence and optimality. To characterize it, we simulate a large cluster of reaction wheels using data obtained from a hardware prototype. Compared to traditional methods, we observe reduced power consumption and more robust convergence when applied to large numbers of actuators. Finally, we generalize the model to encompass multiple inputs-multiple outputs systems. While multiple outputs can easily be accounted for, considering multiple inputs has revealed to be very challenging and only weak results are presented. The second part is devoted to exploiting cluster properties during the preliminary design, leveraging both technological features and analytical conditions to improve design optimization methods. Building on the capabilities developed in the first part, namely the existence of an effective method to coordinate large number of actuators reliably, we present an analytical framework to pursue system design and optimization. A long and dry section of the thesis is devoted to the mathematical characterization of the framework and to provide proofs for its main properties. The abstract assumptions needed for the proposed algorithm are examined, and their validity assessed in the case of a CubeSat design procedure. Finally, a minimal computational implementation is described and applied to GOMX4-B mission.Il settore spaziale sta dimostrando un rinnovato interesse verso concetti basati sull’impiego di sistemi multi-agenti; dallo sviluppo di costellazioni con centinaia di satelliti (mega constellations) a test per architetture federate e dimostratori di assemblaggio in orbita. Inoltre, le piattaforme Cubesat sono ormai uno standard in grado di compiere missioni ambiziose, abbassando quindi il costo di sistemi multi agente. Questo lavoro si propone di studiare i benefici e gli svantaggi di sistemi composti da un grande numero di agenti, quali possono essere degli assemblati in orbita costituiti da innumerevoli satelliti autonomi. Questo documento é diviso in due parti; nella prima ci si concentra su come controllare in maniera affidabile agglomerati composti da un grande numero di attuatori distributi su satelliti diversi. Vengono considerati sia algoritmi centralizzati che decentralizzati per risolvere il problema di allocazione dei compiti; viene infine proposto un nuovo metodo, per il quale vengono fornite dimostrazioni di convergenza. Per caratterizzarne il comportamento, si simula un cluster di ruote di reazione, modellate usando dati ottenuti con un prototipo da laboratorio. In confronto a metodi classici, l’algoritmo proposto mostra un consumo di potenza inferiore e una convergenza piú robusta soprattutto per grandi numeri di attuatori. Infine, si generalizza il modello di attuatore per comprendere anche casi con molteplici input e output. Mentre il caso di molteplici output viene trattato facilmente e differisce di poco dal caso con output singolo, trattare input multipli si é rivelato piuttosto complesso; vengono presentati solo risultati deboli. La seconda parte é dedicata a sfruttare le proprietá dei cluster durante il design preliminare, facendo leva sia su caratteristiche tecnologiche che su proprietá formali per migliorare le procedure di ottimizzazione del desing. Mettendo a frutto i risultati ottenuti nella prima parte, ovvero la capacitá di coordinare in maniera efficace e affidabile un grande numero di attuatori, viene presentato un metodo analitico per l’ottimizzazione di sistema. Una lunga porzione della tesi viene dedicata a dimostrare le proprietá salienti del metodo. Le ipotesi necessarie per applicare il modello vengono esaminate per giudicarne la pretinenza nel caso di design di un cubesat. Infine, una implementazione computazionale viene descritta e applicata alla missione GOMX4-B

Design and Testing of Clustered Components For Modular Spacecraft Architectures

In recent years, the space industry has demonstrated a renewed interest in multi agent systems, from the deployment of large and mega constellations to the plans to test Federated and in orbit assembly concepts. Furthermore, as the CubeSat platform has become a de-facto standard able to support ambitious missions, the cost for multi agent systems has decreased significantly. The aim of this work is to study the benefits and drawbacks of large multi agent systems which might result from in-space assembly of numerous small autonomous spacecraft. The thesis is divided into two parts; in the first we focus on how to efficiently and reliably control large clusters of actuators spread across a modular assembly. We examine both classical centralized and decentralized methods to solve the allocation of tasks within the clusters and finally propose a novel method, for which we provide proof of convergence and optimality. To characterize it, we simulate a large cluster of reaction wheels using data obtained from a hardware prototype. Compared to traditional methods, we observe reduced power consumption and more robust convergence when applied to large numbers of actuators. Finally, we generalize the model to encompass multiple inputs-multiple outputs systems. While multiple outputs can easily be accounted for, considering multiple inputs has revealed to be very challenging and only weak results are presented. The second part is devoted to exploiting cluster properties during the preliminary design, leveraging both technological features and analytical conditions to improve design optimization methods. Building on the capabilities developed in the first part, namely the existence of an effective method to coordinate large number of actuators reliably, we present an analytical framework to pursue system design and optimization. A long and dry section of the thesis is devoted to the mathematical characterization of the framework and to provide proofs for its main properties. The abstract assumptions needed for the proposed algorithm are examined, and their validity assessed in the case of a CubeSat design procedure. Finally, a minimal computational implementation is described and applied to GOMX4-B mission

The Kronecker - Weber Theorem

openIl Teorema di Kronecker – Weber afferma che ogni estensione abeliana del campo dei numeri razionali è contenuta in un’estensione ciclotomica. Ne vedremo una dimostrazione usando gli strumenti base della “class field theory”, il ramo della teoria algebrica dei numeri che studia le estensioni di campi abeliane: gruppi di decomposizione e di inerzia, automorfismo di Frobenius, mappa di Artin, Teorema di reciprocità di Artin per le estensioni abeliane. Premetteremo alcuni argomenti preliminari necessari di algebra commutativa e teoria algebrica dei numeri: domini di Dedekind, ideali frazionari, fattorizzazione degli ideali nei domini di Dedekind; campi di numeri algebrici (“algebraic number fields”), anelli di interi algebrici, fattorizzazione degli ideali nelle estensioni; valutazioni su campi numerici, cenni ai completamenti rispetto a valutazioni archimedee e non archimedee; posti ("places" o "primes") di un’estensione algebrica finita dei razionali (classi di equivalenza di valutazioni)

Uno qualunque

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