1,721,068 research outputs found
A soundscape assessment of the Sasso Fratino Integral Nature Reserve in the Central Apennines, Italy
No full textThis study, based on data collected in 2017, describes for the first time the soundscape of the Sasso Fratino Integral Nature Reserve (INR) in Italy, an area characterised by the almost absence of anthropogenic noise, where we selected three recording sites within and adjacent the reserve. We adopted a double approach: one qualitative, based on visual screening of compact daily spectrograms; the other quantitative, by generating acoustic indices. In general, all sites are characterised by quiet nights and very acoustically dense daylight hours, with a composite biophony occupying the range 1500–9000 Hz. Moreover, the principal component analysis shows that the sites inside and outside the reserve are well differentiated and distinctly clustered, which could be due to their spatial heterogeneity and to the biophony’s different contributions. In this case, our results agree with the recognition of sonic patterns, or sonotopes, related to the different overlapping of biotic and abiotic sonic agents
An advanced mean value method for the treatment of uncertainties in Reliability calculations
No full textThe problem of uncertainties managing in Reliability calculations is stressed.Parametric uncertainties on the failure rate of mechanical components are considered and an approximated method for the determination of the cumulate probability function of the Reliability is shown
DFWM experiments for NO combustion diagnostics
No full textPlath I, Meier U, Kohse-Höinghaus K, Attal-Trétout B. DFWM experiments for NO combustion diagnostics. In: Castellucci F, Righini R, Foggi P, eds. Coherent Raman Spectroscopy: applications and new developments. Singapore: World Scientific Publishing; 1992
An innovative processing method for the direct bathtub calculation
No full text\In many plants, industries, etc. unavailability, often due to neglected or not well performed maintenance, results in reduced revenue and decreasing profitability. It is proved that with good maintenance management methods (usually called Computer Maintenance Management Systems, CMMS) these economic losses can be reduced and the availability improved. But a better result may be obtained intervening at level of maintenance planning. For its improvement, an optimal compromise between the costs of failures repairs and of maintenance operations, carried-out to avoid such failures, has to be found in respect of prefixed constraints on the system availability, reliability, etc. To this aim, reliability criteria must be considered. In this frame, the knowledge of the failure rate of the single components (suitably obtained by the processing of exploitation data previously collected) and, in particular, of its variation in the time has a particular importance. The present paper describes a now method for the processing of the much less than total much greater than failure rate of each component type of an industrial system on the basis of historical data previously collected on it and its possible use for the selection of the only components on which maintenance must be applied and its preliminary definition
Scientific validation of a new system reliability analysis code by means of an existing software
No full textIn the frame of the BRITE-EURAM project BRPR-CT96-0211, financed by the European Commission, a new system reliability analysis code, based on Monte-carlo techniques, was created by Siveco, a French software company partner in the project, specialised in the development of CMMS (Computer Maintenance Management Systems). This code, called RELSYAN, is part of a more complex software tool and it allows the direct simulation of the effects of different maintenance policies on existing engineering systems, taking into consideration their availability and costs. The RELSYAN module was tested by the software producer using elementary analytical tests, but, in consideration of its importance in the economy of the main software tool, a more convincing and complete validation of the code (also considering complex cases, such as failure rates varying in the time, pre-failure conditions, protections, stand-by components and induced failures etc.), resulted necessary. To this aim, another independent Montecarlo software, SPAR (Malchi Science), tested by a long previous experience, was used. In order to allow the execution of such tests, modifications into the user interface and into the logic of SPAR had to be introduced so that a maintenance simulation in a way as closer as possible to RELSYAN was performed by it.The comparisons were carried out oil different simple cases, obtaining similar results. It means that, even if the different approach, the new RELSYAN code may be profitably applied for the maintenance simulation and improvement. Obviously the obtainment of different results from the two codes would have meant that software or modelling problems existed in at least one of them.The paper includes some details on the algorithms used in the two codes for the simulation of maintenance and it is concluded by the results obtained in one of the comparisons carried-out
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Acoustic complexity indices reveal the acoustic communities of the old-growth Mediterranean forest of Sasso Fratino Integral Natural Reserve (Central Italy)
Full text linkThe Sasso Fratino Integral Natural Reserve (Central Italy), a rare example of climax Mediterranean forest, provides an extraordinary opportunity to create an important soundscape reference of old-growth forest. In this study, we describe the soundscape of three localities (Lama, Sasso 950, Sasso 1400) representative of a gradient of variety and complexity of habitats, recorded during the period 10 May to 9 June 2017. Our results reveal temporal partitioning into acoustically homogeneous periods across 24 h suggesting that soniferous species (mainly birds) adopt ecological routines in which their acoustic activity is organized according to specific transient physiological needs. We processed multi-temporal aggregates of 1, 5, 10, and 15 s recordings and calculated the Acoustic Signature (AS) with four new indices: Ecoacoustic Events (EE), Acoustic Signature Dissimilarity (ASD), and their fractal dimensions (DEE and DASD), derived from the Acoustic Complexity Index (ACI). The use of the EE and ASD greatly improved the AS interpretation, adding further details such as the emergence of a clear sequence of patterns consistent with the daily evolution of the overall soundscape. DEE and DASD confirm the patterns observed using the AS, but provide more clarity and detail about the great acoustic complexity that exists across temporal scales in this old-growth forest. The temporal turnover of different acoustic communities occurs as a result of a gradual shift of different homogenous acoustic properties. We conclude that soniferous species use distinct, species-specific temporal resolutions according to their physiological and ecological needs and that the fractal approach used here provides a novel tool to overcome the difficulties associated with describing multi-temporal acoustic patterns
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