133 research outputs found
A Telemetry-driven Approach to Simulate Data-intensive Manufacturing Processes
Abstract Telemetry enables the collection of data from remote points to support monitoring, analysis and visualization. It is largely adopted in Formula One car racing, where streams of live data collected from hundreds of sensors installed on car components are transmitted to the pitwall to be used as input of real-time car performance simulations. The aim of this paper is to evaluate the potential of a telemetry-driven approach in a manufacturing environment, where researchers are still looking for efficient methods to perform valuable simulations of the production processes on the basis of real data coming from the factory. The telemetry could contribute to the implementation of a virtual image of the real factory, which in turn could be used to simulate the factory performance, allowing to predict failures or investigate problems, and to reduce costly downtime. This study addresses in particular the efforts to combine and adapt methods and techniques borrowed from the field of Formula One car racing. Moreover, the investigation of the exploitation possibilities of the factory telemetry is paired with the design of a software application supporting this technology, starting from the elicitation and specification of the functional requirements
Determination of the critical state of granular materials with triaxial tests
Abstract While the Critical State Locus (CSL) determined from triaxial compression tests is commonly adopted for the constitutive modelling of soil, the validity of the locus for other stress paths needs to be proved. Several authors have tried to experimentally verify whether the classical CSL representation in the stress invariants – void ratio space could be considered as unique or should depend on the loading direction, but the question is still being debated and a unique conclusion has not been convincingly drawn. In order to clarify this issue, compression and extension triaxial tests are performed on granular materials with different characteristics, namely, two homogeneously distributed sands and an assembly of steel spheres prepared under different initial conditions. The procedure for identifying the CSL is reviewed and indicates the limitations arising from strain localization (shear bands and necking). All the tests show that the materials head to systematically different traces in the e-p′ and p′-q planes when sheared under triaxial compression and extension. Searching for the reasons for this phenomenon, small samples of sand are subjected to the same tests quantifying the whole strain field with X-ray tomography and a digital image correlation. This analysis reveals an inhomogeneous pattern of deformation that is strongly affected by the presence of the two rigid frictional bases and the flexible side membrane, even for the samples deforming in an apparently uniform manner. The different localization observed for the compression and extension tests justifies the dependence of the CSL on the stress path seen on the global scale. On the other hand, a unique trace of the CSL is obtained in the volumetric e-p′ plane when the void ratio is measured limitedly to the zones affected by the largest distortion
Synchronizing physical and digital factory: benefits and technical challenges
Abstract The Digital Twin is a representation of characteristics and behavior of a factory according to various levels of detail and the scope it addresses. Its full range of capabilities can be exploited when it is synchronized with the real world. Indeed, in this case, it can be used to mirror the real operating conditions for simulating the real-time behavior, and thus forecasting factory performances. However, we are still far from its large-scale diffusion. The purpose of this work is to analyze both the major challenges that still have to be faced and some potential solutions for each of the identified challenges
A SEMANTIC FRAMEWORK FOR GRAPH-BASED ENTERPRISE SEARCH
Various recent studies have shown that in many companies workers can spend near half of their time looking for information. Effective internal search tools could make their job more efficient. However, a killer application for this type of solutions is still not available. This paper introduces an envisioned architecture, which should represent the foundations of a new generation of tools for searching information within enterprises
Adaptive Low-level Storage of Very Large Knowledge Graphs
The increasing availability and usage of Knowledge Graphs (KGs) on the Web
calls for scalable and general-purpose solutions to store this type of data
structures. We propose Trident, a novel storage architecture for very large KGs
on centralized systems. Trident uses several interlinked data structures to
provide fast access to nodes and edges, with the physical storage changing
depending on the topology of the graph to reduce the memory footprint. In
contrast to single architectures designed for single tasks, our approach offers
an interface with few low-level and general-purpose primitives that can be used
to implement tasks like SPARQL query answering, reasoning, or graph analytics.
Our experiments show that Trident can handle graphs with 10^11 edges using
inexpensive hardware, delivering competitive performance on multiple workloads.Comment: Accepted WWW 202
Molecular, clinical, and muscle studies in myotonic dystrophy type 1 (DM1) associated with novel variant CCG expansions
We assessed clinical, molecular and muscle histopathological features in five unrelated Italian DM1 patients carrying novel variant pathological expansions containing CCG interruptions within the 3'-end of the CTG array at the DMPK locus, detected by bidirectional triplet primed PCR (TP-PCR) and sequencing. Three patients had a negative DM1 testing by routine long-range PCR; the other two patients were identified among 100 unrelated DM1 cases and re-evaluated to estimate the prevalence of variant expansions. The overall prevalence was 4.8 % in our study cohort. There were no major clinical differences between variant and non-variant DM1 patients, except for cognitive involvement. Muscle RNA-FISH, immunofluorescence for MBNL1 and RT-PCR analysis documented the presence of ribonuclear inclusions, their co-localization with MBNL1, and an aberrant splicing pattern involved in DM1 pathogenesis, without any obvious differences between variant and non-variant DM1 patients. Therefore, this study shows that the CCG interruptions at the 3'-end of expanded DMPK alleles do not produce qualitative effects on the RNA-mediated toxic gain-of-function in DM1 muscle tissues. Finally, our results support the conclusion that different patterns of CCG interruptions within the CTG array could modulate the DM1 clinical phenotype, variably affecting the mutational dynamics of the variant repeat
Model Organisms Reveal Insight into Human Neurodegenerative Disease: Ataxin-2 Intermediate-Length Polyglutamine Expansions Are a Risk Factor for ALS
Model organisms include yeast Saccromyces cerevisae and fly Drosophila melanogaster. These systems have powerful genetic approaches, as well as highly conserved pathways, both for normal function and disease. Here, we review and highlight how we applied these systems to provide mechanistic insight into the toxicity of TDP-43. TDP-43 accumulates in pathological aggregates in ALS and about half of FTD. Yeast and fly studies revealed an interaction with the counterparts of human Ataxin-2, a gene whose polyglutamine repeat expansion is associated with spinocerebellar ataxia type 2. This finding raised the hypothesis that repeat expansions in ataxin-2 may associate with diseases characterized by TDP-43 pathology such as ALS. DNA analysis of patients revealed that intermediate-length polyglutamine expansions in ataxin-2 are a risk factor for ALS, such that repeat lengths are greater than normal, but lower than that associated with spinocerebellar ataxia type 2 (SCA2), and are more frequent in ALS patients than in matched controls. Moreover, repeat expansions associated with ALS are interrupted CAA-CAG sequences as opposed to the pure CAG repeat expansions typically associated with SCA2. These studies provide an example of how model systems, when extended to human cells and human patient tissue, can reveal new mechanistic insight into disease
Prevalence of interstitial pneumonia suggestive of COVID-19 at 18F-FDG PET/CT in oncological asymptomatic patients in a high prevalence country during pandemic period: a national multi-centric retrospective study
Purpose: To assess the presence and pattern of incidental interstitial lung alterations suspicious of COVID-19 on fluorine-18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) ([18F]FDG PET/CT) in asymptomatic oncological patients during the period of active COVID-19 in a country with high prevalence of the virus. Methods: This is a multi-center retrospective observational study involving 59 Italian centers. We retrospectively reviewed the prevalence of interstitial pneumonia detected during the COVID period (between March 16 and 27, 2020) and compared to a pre-COVID period (January\u2013February 2020) and a control time (in 2019). The diagnosis of interstitial pneumonia was done considering lung alterations of CT of PET. Results: Overall, [18F]FDG PET/CT was performed on 4008 patients in the COVID period, 19,267 in the pre-COVID period, and 5513 in the control period. The rate of interstitial pneumonia suspicious for COVID-19 was significantly higher during the COVID period (7.1%) compared with that found in the pre-COVID (5.35%) and control periods (5.15%) (p < 0.001). Instead, no significant difference among pre-COVID and control periods was present. The prevalence of interstitial pneumonia detected at PET/CT was directly associated with geographic virus diffusion, with the higher rate in Northern Italy. Among 284 interstitial pneumonia detected during COVID period, 169 (59%) were FDG-avid (average SUVmax of 4.1). Conclusions: A significant increase of interstitial pneumonia incidentally detected with [18F]FDG PET/CT has been demonstrated during the COVID-19 pandemic. A majority of interstitial pneumonia were FDG-avid. Our results underlined the importance of paying attention to incidental CT findings of pneumonia detected at PET/CT, and these reports might help to recognize early COVID-19 cases guiding the subsequent management
Cetuximab continuation after first progression in metastatic colorectal cancer (CAPRI-GOIM): A randomized phase II trial of FOLFOX plus cetuximab versus FOLFOX
Background: Cetuximab plus chemotherapy is a first-line treatment option in metastatic KRAS and NRAS wild-type colorectal cancer (CRC) patients. No data are currently available on continuing anti-epidermal growth factor receptor (EGFR) therapy beyond progression. Patients and methods: We did this open-label, 1:1 randomized phase II trial at 25 hospitals in Italy to evaluate the efficacy of cetuximab plus 5-fluorouracil, folinic acid and oxaliplatin (FOLFOX) as second-line treatment of KRAS exon 2 wild-type metastatic CRC patients treated in first line with 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) plus cetuximab. Patients received FOLFOX plus cetuximab (arm A) or FOLFOX (arm B). Primary end point was progressionfree survival (PFS). Tumour tissues were assessed by next-generation sequencing (NGS). This report is the final analysis. Results: Between 1 February 2010 and 28 September 2014, 153 patients were randomized (74 in arm A and 79 in arm B). Median PFS was 6.4 [95% confidence interval (CI) 4.7-8.0] versus 4.5 months (95% CI 3.3-5.7); [hazard ratio (HR), 0.81; 95% CI 0.58-1.12; P = 0.19], respectively. NGS was performed in 117/153 (76.5%) cases; 66/117 patients (34 in arm A and 32 in arm B) had KRAS, NRAS, BRAF and PIK3CA wild-type tumours. For these patients, PFS was longer in the FOLFOX plus cetuximab arm [median 6.9 (95% CI 5.5-8.2) versus 5.3 months (95% CI 3.7-6.9); HR, 0.56 (95% CI 0.33-0.94); P = 0.025]. There was a trend in better overall survival: median 23.7 [(95% CI 19.4-28.0) versus 19.8 months (95% CI 14.9-24.7); HR, 0.57 (95% CI 0.32-1.02); P = 0.056]. Conclusions: Continuing cetuximab treatment in combination with chemotherapy is of potential therapeutic efficacy in molecularly selected patients and should be validated in randomized phase III trials
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