41 research outputs found

    LF radio anomalies revealed in Italy by the wavelet analysis: possible preseismic effects during 1997-1998

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    Since 1996, the electric field strength of the broadcasting station CZE (Czech Republic, f = 270 kHz) has been sampled each ten minutes, by a receiver (AS) located in central Italy, 818 km far from the transmitter. Here, we present the results obtained by a detailed analysis applied on the data recorded from February 1996 up to September 2004. At first, we separated the day time data and the night time data in the radio signals; then, in the day time data we separated the data collected in winter from the data collected in summer. Finally, we applied the wavelet analysis on the previous trends. The first result was the appearance of a very clear anomaly during February– March 1998, at winter day time and at night time. This result confirms an anomaly revealed previously in the same data but analysed with a different approach. The anomaly was related to a strong (M = 5.1–6.0) seismic sequence occurred in a zone (Slovenia) lying in the middle of the transmitter–receiver path. The present result reinforces the hypothesis of the occurrence of some disturbances in the ionosphere during the preparatory phase of the Slovenia seismic sequence. The second result came from the wavelet analysis applied to the summer day time data and it was the appearance of a very clear anomaly during August–September 1997. On September 26 the Umbria– Marche (central Italy) seismic sequence started with two earthquakes with magnitude M = 5.6 and M = 5.9 and the seismic activity lasted for more than six months. We consider the August–September 1997 radio anomaly as a precursor of the previous earthquakes and a possible explanation model is proposed

    A possible preseismic anomaly in the ground wave of a radio broadcasting (216 kHz) during July-August 1998 (Italy)

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    International audienceOn February 1996, a receiver able to measure the electric field strength of LF radio broadcastings, with a sampling frequency of ten minutes, was put into operation in a site (AS) located in central Italy. One of the broadcasting stations selected is MCO (f=216 kHz), located in southeast France, 518 km far from the receiver. The MCO data collected since February 1996 up to September 2004 were examined and, at first, the night time data and the day time data (in winter and summer) were separated. Then, the wavelet analysis on the night and day time data was applied. The main result of the analysis was the appearance of a very clear anomaly during summer (July?August) 1998, at day time and at night time. The anomaly is a strong exaltation of the signal components with period in the 25?40 days range. Theoretical calculations of electric field strength were made and the only way to justify this anomaly seems to be the occurrence of an increase of the ground wave propagation mode of the radio signal. Such an increase could have been produced by an increase of the ground conductivity and by modifications of some parameter of the troposphere, mainly the refractive index. On 15 August 1998 a seismic sequence started with 17 earthquakes (M=2.2?4.6) on the Reatini mountains, a seismogenic zone located 30 km far from the AS receiver along the path MCO-AS. In this paper, the possibility that the previous radio anomaly can be a precursor of this seismic sequence is proposed. </p

    Business analytics in industry 4.0: a systematic review

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    Recently, the term “Industry 4.0” has emerged to characterize several Information Technology and Communication (ICT) adoptions in production processes (e.g., Internet-of-Things, implementation of digital production support information technologies). Business Analytics is often used within the Industry 4.0, thus incorporating its data intelligence (e.g., statistical analysis, predictive modelling, optimization) expert system component. In this paper, we perform a Systematic Literature Review (SLR) on the usage of Business Analytics within the Industry 4.0 concept, covering a selection of 169 papers obtained from six major scientific publication sources from 2010 to March 2020. The selected papers were first classified in three major types, namely, Practical Application, Reviews and Framework Proposal. Then, we analysed with more detail the practical application studies which were further divided into three main categories of the Gartner analytical maturity model, Descriptive Analytics, Predictive Analytics and Prescriptive Analytics. In particular, we characterized the distinct analytics studies in terms of the industry application and data context used, impact (in terms of their Technology Readiness Level) and selected data modelling method. Our SLR analysis provides a mapping of how data-based Industry 4.0 expert systems are currently used, disclosing also research gaps and future research opportunities.The work of P. Cortez was supported by FCT - Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. We would like to thank to the three anonymous reviewers for their helpful suggestions

    Recurrence quantification analysis, variability analysis, and fractal dimension estimation in 99MTc-HDP nuclear scintigraphy of maxillary bones in subjects with osteoporosis

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    We develop a non linear methodology to analyze nuclear medicine images. It holds on Recurrence Quantification Analysis (RQA), on Analysis of Variability by variogram, and on estimation of Fractal Dimension. It is applied to five subjects with osteoporosis in comparison with five control subjects. Bone nuclear images are obtained after administration of 99mTc-HDP. Regions of interest (ROI) are selected in maxillary bones of oral cavity. Some basic non linear indices are obtained as result of the methodology and they enable quantitative estimations at the micro-structural and micro-architectural level of bone matrix investigated. The indices result very satisfactory in discriminating controls from subjects with osteoporosis. Their appear of interest also in the case of dentist intervention often engaged to evaluate oral signs and, in particular, to utilize mandibular or maxillary bones indices in relation to possible loss of bone mineral density and/or to microarchitectural deterioration of bone tissue
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