Search results for "means"
showing 10 items of 124 documents
Diffusion equations with negentropy applied to denoise mammographic images.
2006
Mammography is a radiographic technique used for the detection of breast lesions. The analysis of the digital image normally requires a previous application of filters as a preprocessing step to reduce the noise level of the image, while preserving important details to carry out a suitable diagnostic. In the literature, there are a large amount of denoising techniques applied to different medical images. In this work we have studied the performance of a diffusive filter with a stopping condition based on the statistical concept of negentropy, applied to denoise mammographic images. The negentropy has been succesfully prove with other denoising methods as independent component analysis by th…
On some inequalities for the identric, logarithmic and related means
2015
We offer new proofs, refinements as well as new results related to classical means of two variables, including the identric and logarithmic means.
Exploratory approach for network behavior clustering in LoRaWAN
2021
AbstractThe interest in the Internet of Things (IoT) is increasing both as for research and market perspectives. Worldwide, we are witnessing the deployment of several IoT networks for different applications, spanning from home automation to smart cities. The majority of these IoT deployments were quickly set up with the aim of providing connectivity without deeply engineering the infrastructure to optimize the network efficiency and scalability. The interest is now moving towards the analysis of the behavior of such systems in order to characterize and improve their functionality. In these IoT systems, many data related to device and human interactions are stored in databases, as well as I…
Comunità non solo come mezzo ma anche come fine
2019
L’originaria condizione di inermità all’insegna della quale Kant concepisce la ragione umana rappresenta qualcosa di più della premessa di una storia di progresso in cui l’uomo si rende via via meno inerme e più reattivo al mondo che abita. Tale condizione suggerisce piuttosto il fatto che non disponiamo della ragione allo stesso modo in cui possiamo disporre di qualunque altra dotazione naturale e che, anzi, per quanto possiamo evolverci, rafforzarci nello sviluppo delle nostre conoscenze ed abilità, non muoveremmo un passo in direzione della nostra umanità, quando ci limitassimo a considerare la ragione come un puro mezzo di affermazione e di potere, e non riconoscessimo invece in essa un…
Regional frequency analysis of extreme rainfall in Sicily (Italy)
2018
Extreme rainfall events have large impacts on society and are likely to increase in intensity under climate change. For design and management decisions, particularly regarding hydraulic works, accurate estimates of precipitation magnitudes are needed at different durations. In this article, an objective approach of the regional frequency analysis (RFA) has been applied to precipitation data for the island of Sicily, Italy. Annual maximum series for rainfall with durations of 1, 3, 6, 12, and 24 h from about 130 rain gauges were used. The RFA has been implemented using principal component analysis (PCA) followed by a clustering analysis, through the k-means algorithm, to identify statistical…
Mid-sagittal plane detection for advanced physiological measurements in brain scans
2019
Objective The process of diagnosing many neurodegenerative diseases, such as Parkinson's and progressive supranuclear palsy, involves the study of brain magnetic resonance imaging (MRI) scans in order to identify and locate morphological markers that can highlight the health status of the subject. A fundamental step in the pre-processing and analysis of MRI scans is the identification of the mid-sagittal plane, which corresponds to the mid-brain and allows a coordinate reference system for the whole MRI scan set. Approach To improve the identification of the mid-sagittal plane we have developed an algorithm in Matlab® based on the k-means clustering function. The results have been compared …
Comment on ‘Estimating average annual per cent change in trend analysis’ by Clegg LX, Hankey BF, Tiwari R, Feuer EJ, Edwards BK, Statistics in Medici…
2010
Trends in incidence or mortality rates over a specified time interval are usually described by the conventional annual per cent change (cAPC), under the assumption of a constant rate of change. When this assumption does not hold over the entire time interval, the trend may be characterized using the annual per cent changes from segmented analysis (sAPCs). This approach assumes that the change in rates is constant over each time partition defined by the transition points, but varies among different time partitions. Different groups (e.g. racial subgroups), however, may have different transition points and thus different time partitions over which they have constant rates of change, making co…
Emprendimiento en personas con discapacidad. Un diagnóstico a través de la técnica de grupo nominal
2018
The aim of this work is to identify the dimensions and aspects that foster and / or restrict the entrepreneurial action of disabled people from a qualitative methodological perspective. The analysis was carried out by means of the nominal group technique. As a result of the analysis, this work proposes, through the work done with disabled people, a set of interventions that will reduce barriers and foster the entrepreneurship of such vulnerable group
Means-end analysis: Does the affective state influence information processing style?
2004
Means-end theory aims at explaining how consumers evaluate products by linking relevant attributes to perceived consequences to desired ends in a hierarchical way, based on core assumptions of cognitive psychology about human information processing. This study investigates the influence of affective states on information processing styles in a means-end measurement situation, thus taking into account an important antecedent and correlate of human decision making and behavior that has received scarce attention so far in the methodological literature on means-end chains. The results reveal that a person's affective state indeed influences the style of information processing. Respondents in a …
Optimization of spodumene identification by statistical approach for laser-induced breakdown spectroscopy data of lithium pegmatite ores
2021
Mapping with laser-induced breakdown spectroscopy (LIBS) can offer more than just the spatial distribution of elements: the rich spectral information also enables mineral recognition. In the present study, statistical approaches were used for the recognition of the spodumene from lithium pegmatite ores. A broad spectral range (280–820 nm) with multiple lines was first used to establish the methods based on vertex component analysis (VCA) and K-means and DBSCAN clusterings. However, with a view to potential on-site applications, the dimensions of the datasets must be reduced in order to accomplish fast analysis. Therefore, the capability of the methods in mineral identification was tested wi…