Studio di tecniche di controllo per manipolatori robotici a cedevolezza variabile.

È agli occhi di tutti quale importanza assumano oggi le problematiche relative alla sicurezza. È altresì evidente come nell'industria sia spesso imprescindibile l'uso di manipolatori meccanici e come, anche nella vita di tutti i giorni, la robotica sia un settore in rapido sviluppo. In entrambi i casi la capacità di una macchina di interagire con l'uomo è un requisito fondamentale. L'altro parametro decisivo nella scelta di un modello rispetto ad un altro sono, e sono sempre state, le prestazioni. Si puo' dimostrare che in generale questi due aspetti, sicurezza e prestazioni, non si conciliano facilmente: prediligendo uno dei due, l'altro viene meno. Nel caso specifico dei bracci robotici, infatti, si distinguono i service robot e gli industrial robot. I primi, disegnati per la convivenza e la collaborazione con gli esseri umani, risultano sicuri ma poco performanti, gli ultimi, disegnati per applicazioni in cui sono necessarie potenza e velocità, sono invece molto pericolosi per chi ci vive a contatto. L'obiettivo, in quest'ultimo decennio, è riuscire a conciliare le caratteristiche peculiari degli uni e degli altri. A livello progettuale due strade sono state finora percorse separatemente: migliorare l'hardware, la struttura del manipolatore, oppure migliorare il sofware, la politica di controllo degli attuatori. Si sono distinte allora rispettivamente tecniche di passive compliance e active compliance. La compliance (cedevolezza) di un manipolatore è una caratteristica fondamentale per dare l'idea di quanto questo possa essere "amichevole" nei confronti dell'ambiente esterno. Questo lavoro, inizialmente, si prefigge di definire un metodo di valutazione oggettivo per il livello di sicurezza e per le potenzialità in termini di prestazioni, limitatamente al caso dei manipolatori robotici. In base a quest'ultimo, viene valutato il trade-off che ne risulta per un semplice sistema ad un grado di libertà. Vengono poi esposte due soluzioni esistenti pensate per risolvere tale compromesso. Infine si propone una nuova metodologia di co-design meccanico e controllistico chiamata VST (Variable Stiffness Transmission), ispirata alla biologia del braccio umano, che promette un decisivo apporto teorico e pratico alla materia in discussione. Risultati in simulazione e possibili implementazioni pratiche sono nondimeno inclusi

Mechanisms of Disease Progression and Resistance to Tyrosine Kinase Inhibitor Therapy in Chronic Myeloid Leukemia: An Update

Chronic myeloid leukemia (CML) is characterized by the presence of the BCR-ABL1 fusion gene, which encodes a constitutive active tyrosine kinase considered to be the pathogenic driver capable of initiating and maintaining the disease. Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1, some patients may not respond (primary resistance) or may relapse after an initial response (secondary resistance). In a small proportion of cases, development of resistance is accompanied or shortly followed by progression from chronic to blastic phase (BP), characterized by a dismal prognosis. Evolution from CP into BP is a multifactorial and probably multistep phenomenon. Increase in BCR-ABL1 transcript levels is thought to promote the onset of secondary chromosomal or genetic defects, induce differentiation arrest, perturb RNA transcription, editing and translation that together with epigenetic and metabolic changes may ultimately lead to the expansion of highly proliferating, differentiation-arrested malignant cells. A multitude of studies over the past two decades have investigated the mechanisms underlying the closely intertwined phenomena of drug resistance and disease progression. Here, we provide an update on what is currently known on the mechanisms underlying progression and present the latest acquisitions on BCR-ABL1-independent resistance and leukemia stem cell persistence

Exploring the Limits of Multi-Antenna Signal-Rejection for GNSS Receivers

This paper presents experimental results exploring the performance of GNSS receivers equipped with controlled radiation pattern antennas. Experiments focus on identifying those features and characteristics of their implementation that may limit the achievable performance of signal-rejection techniques. The study describes both conductive and broadcast experiments conducted in a large anechoic chamber and computer-based Monte-Carlo simulations. Results include a precise gain pattern measurement of a typical antenna array, an investigation and comparison of both analogue RF and digital IF null steering along with some novel theoretical results.JRC.G.5-Security technology assessmen

On the Threat of Systematic Jamming of GNSS

This paper presents a study of the threat of malicious interference to GNSS and examines the special case where the jamming device is incrementally more sophisticated than a typical always-on interference source. The concept of a systematic jamming attack is considered, where the interference signal is intentionally synchronized with the GNSS signals, with the intention of causing maximum disruption with the minimum power expenditure. Various attack methodologies are examined for the case of a civilian L1 receiver. It is shown that, depending on the attack strategy, the target signal and the target receiver, data-recovery, navigation and timing can be denied to a user with some tens of decibels less average power than a traditional jamming attack. It is further shown that some attacks may be capable to effectively deny some receiver functionality in a subtle manner such that presence of the malicious interference goes undetected. Key signal and receiver features that expose a vulnerability are identified and some means of improving receiver robustness are provided

Getting better all the time - The Continued Evolution of the GNSS Software-Defined Radio

Software Defined Radio (SDR) has an infinite number of interpretations depending on the context in which it is designed and used. By way of a starting definition the authors choose to use that of ‘a reconfigurable radio system whose characteristics are partially or fully defined via software or firmware’. In various forms, SDR has permeated a wide range of user groups, from military, business, academia and to the amateur radio enthusiast

La funzione del contratto collettivo. Salari, produttività, mercato del lavoro

Il volume si propone di ripensare, da una prospettiva giuslavoristica e di relazioni industriali, le molteplici funzioni della contrattazione collettiva come istituzione sociale e “fonte” di regolazione dei rapporti di lavoro. L’attenzione è rivolta alle recenti trasformazioni del lavoro, che sembrano confermare la persistente centralità del contratto collettivo chiamando tuttavia gli attori sociali a una profonda rivisitazione di questo storico istituto, così da fornire risposte attuali ai problemi del mercato del lavoro. Questo a partire dal nodo dell’adeguatezza dei salari rispetto ad un mercato del lavoro estremamente polarizzato, che registra, da un lato, il dilagare di forme di lavoro povero e, dall’altro, l’ampliamento del lavoro professionalizzato, le cui tutele economiche si determinano prescindendo dal trattamento minimo stabilito dai contratti collettivi e che tuttavia necessitano di un’infrastruttura sociale e di tutele moderne rispetto ai nuovi rischi e alle continue transizioni occupazionali. Attraverso l’analisi della prassi contrattual-collettiva il volume offre nuove prospettive e nuove soluzioni per interpretare i processi di trasformazione della funzione del contratto collettivo

In chronic myeloid leukemia patients on second-line tyrosine kinase inhibitor therapy, deep sequencing of BCR-ABL1 at the time of warning may allow sensitive detection of emerging drug-resistant mutants

BACKGROUND: Imatinib-resistant chronic myeloid leukemia (CML) patients receiving second-line tyrosine kinase inhibitor (TKI) therapy with dasatinib or nilotinib have a higher risk of disease relapse and progression and not infrequently BCR-ABL1 kinase domain (KD) mutations are implicated in therapeutic failure. In this setting, earlier detection of emerging BCR-ABL1 KD mutations would offer greater chances of efficacy for subsequent salvage therapy and limit the biological consequences of full BCR-ABL1 kinase reactivation. Taking advantage of an already set up and validated next-generation deep amplicon sequencing (DS) assay, we aimed to assess whether DS may allow a larger window of detection of emerging BCR-ABL1 KD mutants predicting for an impending relapse. METHODS: a total of 125 longitudinal samples from 51 CML patients who had acquired dasatinib- or nilotinib-resistant mutations during second-line therapy were analyzed by DS from the time of failure and mutation detection by conventional sequencing backwards. BCR-ABL1/ABL1%(IS) transcript levels were used to define whether the patient had 'optimal response', 'warning' or 'failure' at the time of first mutation detection by DS. RESULTS: DS was able to backtrack dasatinib- or nilotinib-resistant mutations to the previous sample(s) in 23/51 (45 %) pts. Median mutation burden at the time of first detection by DS was 5.5 % (range, 1.5-17.5 %); median interval between detection by DS and detection by conventional sequencing was 3 months (range, 1-9 months). In 5 cases, the mutations were detectable at baseline. In the remaining cases, response level at the time mutations were first detected by DS could be defined as 'Warning' (according to the 2013 ELN definitions of response to 2nd-line therapy) in 13 cases, as 'Optimal response' in one case, as 'Failure' in 4 cases. No dasatinib- or nilotinib-resistant mutations were detected by DS in 15 randomly selected patients with 'warning' at various timepoints, that later turned into optimal responders with no treatment changes. CONCLUSIONS: DS enables a larger window of detection of emerging BCR-ABL1 KD mutations predicting for an impending relapse. A 'Warning' response may represent a rational trigger, besides 'Failure', for DS-based mutation screening in CML patients undergoing second-line TKI therapy

Phase scintillation decorrelation impact on multi-frequency users

This paper discusses the phase scintillation decorrelation as observed between dual and triple frequency civil GNSS signals. Comparisons are made between the characteristics of data collected in Norway during events of strong and persistent phase activity versus data collected in Hanoi during periods of vigorous amplitude and phase scintillation. Under both types of scintillation activity a degree of decorrelation is observed between the multiple carriers which is not attributable to nominal ionospheric behavior, and in turn the assumption that the ionosphere-free combination is for all intents and purposes free of the influence of the ionosphere is violated.submittedVersio