Collecting and Analyzing Failure Data of Bluetooth Personal Area Networks

This work presents a failure data analysis campaign on Bluetooth Personal Area Networks (PANs) conducted on two kind of heterogeneous testbeds (working for more than one year). The obtained results reveal how failures distribution are characterized and suggest how to improve the dependability of Bluetooth PANs. Specically, we dene the failure model and we then identify the most effective recovery actions and masking strategies that can be adopted for each failure. We then integrate the discovered recovery actions and masking strategies in our testbeds, improving the availability and the reliability of 3.64% (up to 36.6%) and 202% (referred to the Mean Time To Failure), respectively

Innovative procedure for measurement uncertainty evaluation of environmental noise accounting for sound pressure variability

2015 - 2016This study aims to demonstrate the importance of uncertainty evaluation in the measurement of environmental noise in the context of Italian legislation on noise pollution. Attention is focused on the variability of the measurand as a source of uncertainty and a procedure for the evaluation of uncertainty for environmental noise measurement is proposed. First drawing on several real noise datasets in order to determine suitable measurement time intervals for the estimation of the environmental noise, a data-driven sampling strategy is proposed, which takes into account the observed variability associated with measured sound pressure levels. Outliers are eliminated from the actual noise measurements using an outlier detection algorithm based on K-neighbors distance. As the third step, the contribution of measurand variability on measurement uncertainty is determined by using the normal bootstrap method. Experimental results exploring the adoption of the proposed method drawing upon real data from environmental noise using acquisition campaigns confirm the reliability of the proposal. It is shown to be very promising with regard to the prediction of expected values and uncertainty of traffic noise when a reduced dataset is considered. [edited by author]Negli ultimi anni, studiosi ed esperti del settore hanno focalizzato la loro attenzione sulle possibili fonti di incertezza associabili a tale attività, cercando di pervenire a modelli che contemplassero tutte le variabili che concorrono alla determinazione dell’incertezza nella misura dei livelli di pressione acustica: l'incertezza dovuta alle caratteristiche della strumentazione di misura (fonometri o analizzatori multicanale), l'errore derivante dal posizionamento della strumentazione e quindi dei trasduttori microfonici, l'incertezza dovuta al calibratore, nonché l’incertezza da associare. Al fine, però, di fornire un’adeguata stima dell’indeterminazione associata alla misura del livello equivalente di rumore ambientale, risulta indispensabile considerare l’incertezza derivante dall’intrinseca variabilità del fenomeno in esame. Il tema risulta essere di particolare interesse scientifico e, negli ultimi anni, molti autori hanno proposto diverse metodologie di approccio al suddetto problema, in particolare alcuni hanno focalizzato l’attenzione sull’eliminazione dei segnali sonori non desiderati, altri sulla stima del tempo di misura e altri ancora direttamente sulla determinazione dell’incertezza. Alla luce di quanto esposto, ho pensato di integrare le diverse tecniche studiate in un’unica procedura, basata sul metodo bootstrap, tecnica statistica di ricampionamento con sostituzione del dataset iniziale, in quanto non ha limitazioni in termini di forma e di proprietà delle distribuzioni statistiche considerate ed è, pertanto, più adatta all’analisi del rumore ambientale, la cui popolazione non è strettamente gaussiana. Inizialmente, dal momento che l’affidabilità della stima degli indicatori di rumore ambientale dipende in modo significativo dalla variabilità temporale del rumore, e, quindi, risulta fondamentale scegliere in modo accurato il tempo di misura che tenga in considerazione la variabilità statistica del fenomeno acustico sotto osservazione, l’algoritmo individua in modo automatico un tempo minimo di acquisizione, corrispondente al numero minimo di livelli pressione sonora necessari a garantire la significatività statistica del set di dati di partenza. In una seconda fase sono individuati ed eliminati dal segnale acquisito eventuali valori anomali (outlier) ed, infine, è calcolata l’incertezza relativa al misurando applicando il metodo bootstrap. I risultati di tale metodo sono stati anche confrontati con la stima del valore atteso per il descrittore acustico a breve termine e della corrispondente incertezza applicando il metodo classico (GUM ISO). Poiché le grandezze calcolate con l’applicazione del metodo bootstrap si avvicinano molto a quelle determinate con il metodo classico nell’ipotesi di ridotto numero di campioni, tale procedura risulta altresì particolarmente adatta alla previsione dell'indicatore di rumore ambientale quando sono disponibili pochi dati di misura. [a cura dell'autore]XV n.s. (XXIX

Clinical Significance of FGF-23 in Patients with CKD

FGF23 is a bone-derived hormone that plays an important role in the regulation of phosphate and 1,25-dihydroxy vitamin D metabolism. FGF23 principally acts in the kidney to induce urinary phosphate excretion and suppress 1,25-dihydroxyvitamin D synthesis in the presence of FGF receptor 1 (FGFR1) and its coreceptor Klotho. In patients with chronic kidney disease (CKD), circulating FGF23 levels are progressively increased to compensate for persistent phosphate retention, but this results in reduced renal production of 1,25-dihydroxyvitamin D and leads to hypersecretion of parathyroid hormone. Furthermore, FGF23 is associated with vascular dysfunction, atherosclerosis, and left ventricular hypertrophy. This paper summarizes the role of FGF23 in the pathogenesis of mineral, bone, and cadiovascular disorders in CKD

Inductive Logic Programming as Abductive Search

We present a novel approach to non-monotonic ILP and its implementation called TAL (Top-directed Abductive Learning). TAL overcomes some of the completeness problems of ILP systems based on Inverse Entailment and is the first top-down ILP system that allows background theories and hypotheses to be normal logic programs. The approach relies on mapping an ILP problem into an equivalent ALP one. This enables the use of established ALP proof procedures and the specification of richer language bias with integrity constraints. The mapping provides a principled search space for an ILP problem, over which an abductive search is used to compute inductive solutions

Towards Secure Monitoring and Control Systems: Diversify!

This work discusses the role of diversity as a mean towards secure monitoring and control. The intuition underlying the proposal is that diversity can be leveraged to raise the effort it takes to conduct a successful attack (in terms of attack resources and time) to such a level so as to make it pointless to attempt an attack at all. For example, let us consider an attack that requires compromising two machines in order to be successful. If the machines are identical, it suffices to compromise one machine and then repeating the exploit for the other, i.e., the chance of a successful attack PSA to the system is related to the chance of compromising just one machine (PSA≈PM). When the machines are different, PSA is smaller because it becomes somewhat related to chance of compromising each machine separately (i.e., PSA≈PM1×PM2): succeeding is harder and time-consuming. Diversity is not used here to replicate components. We claim that a monitoring and control system, when possible, can smartly combine diverse technologies to significantly increase the effort to conduct a successful attack. Key aspects, issues and future research directions are briefly discussed in the following

Solid particle erosion and viscoelastic properties of thermoplastic polyurethanes

The wear resistance of several thermoplastic polyurethanes (TPUs) having different chemical nature and micronscale arrangement of the hard and soft segments has been investigated by means of erosion and abrasion tests. The goal was correlating the erosion performances of the materials to their macroscopic mechanical properties. Unlike conventional tests, such as hardness and tensile measurements, viscoelastic analysis proved to be a valuable tool to study the erosion resistance of TPUs. In particular, a strict correlation was found between the erosion rate and the high-frequency (~10^7 Hz) loss modulus. The latter reflects the actual ability of TPU to dissipate the impact energy of the erodent particles

Combined ND techniques for structural assessment: the case of historic Nepali constructions after the 2015 Gorkha earthquake

Combined non-destructive in situ techniques—namely sonic tests and ambient vibration measurements—are applied on two Nepali Pagoda temples damaged by the 2015 Gorkha earthquake, providing the dynamic elastic modulus of masonry and the buildings' frequencie

Small Pilot Survey on Parents' Perception of the Relationship between Children and Pets

Since companion animals are taking on more important roles in family life, the aim of this study was to evaluate the perception of parents about the relationship between their children and pets. A number of parents were asked to fill in a questionnaire; the principal topics were: pet ownership, pet care, relationship between pets and children, and sources of information about pet management. Eighty-two parents completed the survey; 71.4% of them already had pets before having children; pet care and health has emerged to be rather important, since 96.4% of the pets are taken to the veterinarian at least once a year; moreover, the great majority of the parents (97.2%) were not worried about the possible risks, linked to pets, pertaining to their child’s health. The present survey confirms that pets are mostly considered as members of the family, and not only as a benefit for the children. Moreover, the relationship between children and pets is basically seen as a positive experience for children

Diagnostic Workup for Disorders of Bone and Mineral Metabolism in Patients with Chronic Kidney Disease in the Era of KDIGO Guidelines

KDIGO (Kidney Disease: Improving Global Outcomes) is an international nonprofit organization devoted to “improve the care and outcomes of kidney disease patients worldwide through promoting coordination, collaboration, and integration of initiatives to develop and implement clinical practice guidelines.” The mineral and bone disorder (MBD) in patients with chronic kidney disease (CKD) has been the first area of interest of KDIGO international initiative. KDIGO guidelines on CKD-MBD were published in 2009 with the intent to modify the previous KDOQI guidelines that had failed to consistently change the global outcome of CKD patients. After the publication of KDOQI guidelines for bone metabolism and disease in 2003, a large number of observational data emerged in literature linking disordered mineral metabolism with adverse clinical outcomes. Notwithstanding this large body of observational data, a paucity of evidence from high-quality clinical trials was available for the development of KDIGO guidelines. Herein, a summary will be provided of the most important findings of KDIGO guidelines regarding the diagnostic workup and clinical monitoring of CKD-MBD patients