Search results for "multidimensional"

LEADING SECONDARY SCHOOL STUDENTS TO FACE THE DISCIPLINARY, EPISTEMOLOGICAL AND SOCIETAL CHALLENGES OF CLIMATE CHANGE: DESIGN AND ANALYSIS OF MULTI-D…

The scientific community has been debating climate change (CC) for over two decades. In the light of certain arguments put forward by the aforesaid community, the EU has recommended a set of innovative reforms to science teaching, such as incorporating environmental issues into the scientific curriculum, thereby helping to make schools a place of civic education. However, despite these European recommendations, relatively little emphasis is still given to climate change within science curricula. The main goal of the research project described in this thesis is to study if, how and why the scientific contents related to CC could be reconstructed so as to integrate the many dimensions involve…

Visual Data Mining With Self-organizing Maps for “Self-monitoring” Data Analysis

2016

Data collected in psychological studies are mainly characterized by containing a large number of variables (multidimensional data sets). Analyzing multidimensional data can be a difficult task, especially if only classical approaches are used (hypothesis tests, analyses of variance, linear models, etc.). Regarding multidimensional models, visual techniques play an important role because they can show the relationships among variables in a data set. Parallel coordinates and Chernoff faces are good examples of this. This article presents self-organizing maps (SOM), a multivariate visual data mining technique used to provide global visualizations of all the data. This technique is presented as…

A Novel Multidimensional Scaling Technique for Mapping Word-Of-Mouth Discussions

2009

The techniques which utilize Multidimensional Scaling (MDS) as a fundamental statistical tool have been well developed since the late 1970’s. In this paper we show how anMDS scheme can be enhanced by incorporating into it a Stochastic Point Location (SPL) strategy (one which optimizes the former’s gradient descent learning phase) and a new Stress function. The enhanced method, referred to as MDS SPL, has been used in conjunction with a combination of the TF-IDF and Cosine Similarities on a very noisy Word-Of-Mouth (WoM) discussion set consisting of postings concerning mobile phones, yielding extremely satisfying results.

L'etichettatura dei prodotti agroalimentari nella percezione della qualità secondo i consumatori.

2014

Le informazioni sulle certificazioni di qualità o sulla filiera di produzione, confezionamento e vendita sono, per i consumatori, elementi importanti per individuare prodotti ritenuti sicuri. Tali informazioni, se riportate in etichetta, sono determinanti nelle scelte d’acquisto di taluni segmenti di mercato. L’obiettivo di questo studio è conoscere in che misura la rintracciabilità dei prodotti alimentari, rivelata ai consumatori attraverso le etichette, possa essere considerata un elemento rappresentativo della qualità e della sicurezza, anche attraverso l’utilizzo di strumenti innovativi quale il QR code. Sono stati individuati due Capoluoghi italiani, sulla base della suddivisione ISTAT…

Multidimensional Scaling in Cluster Analysis: examples in Science and Mathematics Education

2021

Several researches in STEM education research highlight the advantages of an inte- grated approach to these disciplines that relates knowledge and know-how, design and implementation, theoretical and practical problems [5, 4, 6]. In some researches, the effectiveness of these approaches on students conceptual understanding and motivation and has been studied through the use of quantitative analysis tools such as cluster analysis (CLA) [1, 7]. Through CLA it is possible to characterize students analyzing the strategies they deploy to tackle, for example, questionnaires built so as to investigate the lines of reasoning implemented by them when they are proposed with problematic situations. In…

Association between multidimensional prognostic index (MPI) and infections in a population of older people affected by COVID-19

2023

Background: Only limited studies analyzed a possible relationship between frailty and infections. Our aim was to investigate the possible association between higher multidimensional prognostic index (MPI) values, a tool for evaluating multidimensional frailty, and the prevalence of infectious diseases, including antibiotics' cost and the prevalence of MDR (multidrug resistance) pathogens. Methods: Older patients, affected by COVID-19, were enrolled in the hospital of Palermo over four months. Results: 112 participants (mean age 77.6, 55.4% males) were included. After adjusting for potential confounders, frailer participants had a higher odds of any positivity to pathogens (prevalence: 61.5%…

I siti web delle catene alberghiere italiane. Un'applicazione della teoria

2002

Per conoscere in che modo alcuni operatori del settore turistico comunicano la loro immagine al mercato mondiale attraverso l’utilizzo di reti telematiche, ho pensato di condurre un’analisi dei siti web delle catene alberghiere italiane. Obiettivo principale del lavoro è la conoscenza del modo in cui il turismo ed i servizi offerti dagli alberghi, raggruppati in catene alberghiere, vengono comunicati in forma associativa sul web. Per raggiungere questo scopo, è necessario misurare la capacità comunicativa dei siti esaminati partendo dalla considerazione che il web va considerato come un prodotto di relazioni sociali. Per procedere a quest’analisi, utilizzerò la teoria multidimensionale dell…

Measuring sustainable economic development through a multidimensional Gini index

2016

This paper analyses the evolution of sustainable economic development inequality in Italy as regards the efforts made by each administrative Region, as a response to the main EU policies issued by the environmental and energy sector. For this purpose a multidimensional generalization of the Gini index has been performed, taking into account two different dimensions (energy and environment), in a time frame of six years (2008-2013). The multidimensional Gini results confirm the positive effect recorded by certain EU policies in determining a reduction in the inequality levels among the Italian Regions. A counterfactual analysis further underlined the relevant role played by the energetic dim…

Defining and measuring the development of a country over time

2012

This paper introduces the concept of harmonic growth as an extended acceptation of the notion of development, and discusses its measurement via the Harmonic Growth Index (HGI). The growth is seen as harmonic when the behaviour of a benchmark time series, which here is a measure of wealth, such as per capita GDP, is followed by a similar pattern in socio-economic series. Unlike most widely used indicators in the literature, which take into account the measurement of development over a single time, HGI measures the degree to which a social indicator’s time series pattern matches with the GDP’s. The index is a function, ranging in [0, 1], of the coefficients of the uniform B-splines fitted to …

Generation of multidimensional random pulses for radioactivity measurements

2000

Multidimensional binary pseudo-random pulses are extremely useful for the set-up calibration and testing of radioactivity measuring equipment. A new method of generation of such signals, based on the parting operation of labeled pulse trains, is presented. The concept of a general coincidence ratio is introduced. Digital window comparators and prohibited or permitted state programmers capable of performing the parting operation and controlling the values of the coincidence ratio are proposed.