1,265 research outputs found
Condition-Based Monitoring on High-Precision Gearbox for Robotic Applications
This work presents a theoretical and experimental study regarding defect detection in a robotic gearbox using vibration signals in both cyclostationary and noncyclostationary conditions. The existing work focuses on inferring the health of the robot during operation with little regard toward the defective element of the components. This article illustrates the detection of specific element damage of a robotic gearbox during a robotic cycle based on domain knowledge and presents a novel data-driven method for asset health. This starts by studying the robotic gearbox, specifically its kinematics as a planetary 2-stage reduction gearbox to acquire the knowledge of the rotations of each component. The signals acquired from a test bench with four sensors undergo different acquisition methods and signal processing techniques to correlate the elements' frequencies. The work shows the detection of the artificially created defects from the acquired vibration data, verifying the kinematic methodology and identifying the root cause of failure of such gearboxes. A novel resampling method, Binning, is presented and compared with the traditional signal processing techniques. Binning combined with Principal Component Analysis (PCA) as a data-driven method to infer the state of the gearbox is presented, tested, and validated. This work presents methods as a step toward automatized predictive maintenance on robots in industrial applications
EXPO-AGRI: Smart Automatic Greenhouse Control
Predicting and controlling plant behavior in con- trolled environments is a growing requirement in precision agri- culture. In this context sensor networks and artificial intelligence methods represent key aspects for optimizing the processes of data acquisition, mathematical modeling and decision making. In this paper we present a general architecture for automatic greenhouse control. In particular, we focus on a preliminary model for predicting the risk of new infections of downy mildew of basil (Peronospora belbahrii) on sweet basil. The architecture has three main elements of innovation: new kinds of sensors are used to extract information about the state of the plants, model predictors are generated from this information by non-trivial processing methods, and informative predictors are automatically selected using regularization techniques
Unprecedented studies of the low-energy negatively charged kaons interactions in nuclear matter by AMADEUS
The AMADEUS experiment aims to provide unique quality data of hadronic
interactions in light nuclear targets, in order to solve fundamental open
questions in the non-perturbative strangeness QCD sector, like the
controversial nature of the state, the yield of hyperon
formation below threshold, the yield and shape of multi-nucleon
absorption, processes which are intimately connected to the possible existence
of exotic antikaon multi-nucleon clusters. AMADEUS takes advantage of the
DANE collider, which provides a unique source of monochromatic
low-momentum kaons and exploits the KLOE detector as an active target, in order
to obtain excellent acceptance and resolution data for nuclear capture on
H, He, Be and C, both at-rest and in-flight. During the
second half of 2012 a successful data taking was performed with a dedicated
pure carbon target implemented in the central region of KLOE, providing a high
statistic sample of pure at-rest nuclear interactions. For the future
dedicated setups involving cryogenic gaseous targets are under preparation.Comment: 14 pages, 6 figure
Collagen proportionate area predicts long-term mortality in patients with alcoholic hepatitis
Background and aims: There are several short-term prognostic scores for alcoholic hepatitis (AH) that combine demographical and biochemical parameters. The extent of liver fibrosis may also be relevant to the prognosis of AH with potential added value. We evaluated collagen proportionate area (CPA) as a predictor of short and long-term mortality in AH. Methods: We retrospectively included patients with biopsy-verified AH. Clinical, laboratory and outcome data were collected. CPA and five AH scores were calculated: Maddrey's DF, MELD, GAHS, ABIC, and the Lille Model. Predictors of short and long-term all-cause mortality were assessed using Cox regression analysis. Results: We included 140 patients with AH. In total, 67 (48%) patients died after a median follow-up of 66 (IQR 102) months, with 17 (12%) dying within the first 90-days. CPA was not a predictor of 90-days mortality and had no additional value to the prognostic AH scores on short-term mortality. However, CPA predicted long-term mortality independently of prognostic AH scores. Importantly, CPA and abstinence from alcohol were independent predictors of long-term mortality in patients alive 90 days after the biopsy. Conclusion: CPA predicts long-term mortality in patients with AH independently of abstinence from alcohol but has no prognostic value on short-term mortality
Ottimizzazione del processo di pressocolata per il miglioramento delle prestazioni meccaniche in caso di impatto
Le prestazioni di un componente in lega di alluminio soggetto a prova di impatto si definiscono sulla basedell’energia assorbita durante l’urto e il transitorio di smorzamento della velocità del corpo impattante. I test egli strumenti di laboratorio sono onerosi e sofisticati per ogni componente, ma attualmente costituisconol’approccio ideale per il collaudo finale del componente, a meno che gli strumenti CAE siano in grado disostituire (almeno in parte) i test reali. Un tale obiettivo è sicuramente ambizioso in quanto richiede un’attentaricerca e comprensione dei fattori che concorrono a definire il comportamento elasto-plastico a rottura delmateriale. Ancor più delicata è la caratterizzazione del materiale nel caso di pressocolati in lega di alluminiodove le proprietà meccaniche dipendono fortemente dai difetti di fonderia piuttosto che dalla microstruttura.Il progetto NADIA (New Automotive components Designed for and manufactured by Intelligent processing oflight Alloys, Thematic priorities 3 – NMP, Contract N°: 026563-2) del FP6 è stato valutato come il progetto diriferimento nel settore automotive per l’integrazione del processo manifatturiero con la risposta meccanica deicomponenti in lega leggera. Al termine della ricerca di base sulle leghe secondarie e sugli effetti degli elementie i parametri di processo sulle prestazioni del materiale, il progetto prevede l’applicazione ingegneristica dellenuove conoscenze e modelli. Con particolare riferimento ad uno dei dimostratori, il “Rack&Pinion” della CIEAutomotive, un nuovo strumento ingegneristico è in grado oggi di trasferire la previsione delle proprietàmeccaniche del getto (MAGMASOFT) in un codice FEM per simulazione di impatto (LS-DYNA) attraversoun’avanzata correlazione fra la tensione di rottura locale e i più significativi indici di difettologia peringlobamento da gas o porosità da ritiro
The Comparative Political Economy of Basel III in Europe
The Basel III Accord was the centrepiece of the international regulatory response to the global financial crisis, setting new capital requirements for internationally active banks. This paper explains the divergent preferences on Basel III of national regulators in three countries that approximate what are frequently presented as distinct varieties of capitalism in Europe — Germany, the United Kingdom and France. It is argued that national regulators setting post crisis capital requirements had to reconcile three inter-related and potentially conflicting objectives: banking sector stability, the competitiveness of national banks and short to medium term economic growth. The different national preferences on Basel III reflected how different national regulators defined and pursued these objectives, which in turn reflected the structure of national banking systems — specifically, systemic patterns of bank capital and bank-industry ties
The 'ebb and flow' of transatlantic regulatory cooperation in banking
Do financial crises promote or hamper transatlantic regulatory cooperation in banking? This article argues that financial crises have an impact upon the alignment of regulatory preferences of the United States (US) and the European Union (EU), causing an 'ebb and flow' in transatlantic cooperation. When EU-US preferences are broadly aligned in periods of financial stability, transatlantic regulatory cooperation is intense. It is relatively easy for the EU and US to agree on market-friendly regulation promoted by banks. When preferences are different, especially in the context and aftermath of the exogenous shock of financial crises, transatlantic cooperation is more problematic because crises re-assert the importance of nationally embedded patterns of market organisation
Polineuropatía desmielinizante inflamatoria crónica como forma de presentación de lupus eritematoso sistémico
Se describe el caso de una mujer de 35 años que presenta polineuropatía desmielinizante inflamatoria crónica como compromiso neurológico en su diagnóstico inicial de lupus eritematoso sistémico (LES). Si bien el compromiso neurológico es de una prevalencia variable en lupus, la asociación que se describe no es frecuente y tiene importantes connotaciones en el tratamiento
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