Search results for "cluster analysis"
showing 10 items of 848 documents
Improving the accuracy of rainfall prediction using a regionalization approach and neural networks
2018
Spatial and temporal analysis of precipitation patterns has become an intense research topic in contemporary climatology. Increasing the accuracy of precipitation prediction can have valuable results for decision-makers in a specific region. Hence, studies about precipitation prediction on a regional scale are of great importance. Artificial Neural Networks (ANN) have been widely used in climatological applications to predict different meteorological parameters. In this study, a method is presented to increase the accuracy of neural networks in precipitation prediction in Chaharmahal and Bakhtiari Province in Iran. For this purpose, monthly precipitation data recorded at 42 rain gauges duri…
Esperienze sfavorevoli infantili ed esiti psicopatologici: cluster analysis su campioni clinici e non clinici mediante la Childhood Experience of Car…
2012
Gli eventi traumatici esperiti durante l’infanzia hanno un’influenza rilevante sulla strutturazione del Sé nascente del bambino (Bifulco & Moran,1998; Jurist et al., 2008; Schimmenti & Bifulco, 2008). L’impatto di tali eventi e i loro possibili esiti psicopatologici variano in maniera significativa in relazione alla presenza simultanea di molteplici e pervasive esperienze negative e all’età in cui esse si verificano (Cook et al., 2005; van der Kolk, 2005). Questo contributo propone un’analisi esplorativa finalizzata ad individuare, attraverso la metodologia della cluster analysis, tipologie rappresentative dei diversi pattern di esperienze sfavorevoli infantili. Vengono, inoltre, analizzate…
Areas of research and clinical approaches to the study of liver abscess
2016
AIM To analyze the research activity on liver abscess (LA) and identify the main topic clusters in the area. METHODS We identified all documents using the medical subject heading "LA" indexed in the MEDLINE database between 2001 and 2015. We performed a descriptive bibliometric analysis, characterizing the evolution of scientific activity, the publication types of the documents, the document categories of clinical interest (case reports, clinical trials, evaluation studies, meta-analysis, observational studies, practice guidelines and validation studies) and the geographic distribution of the research. We also carried out an analysis of networks and research clusters in order to identify th…
Maternal Oct-4 is a potential key regulator of the developmental competence of mouse oocytes
2008
Abstract Background The maternal contribution of transcripts and proteins supplied to the zygote is crucial for the progression from a gametic to an embryonic control of preimplantation development. Here we compared the transcriptional profiles of two types of mouse MII oocytes, one which is developmentally competent (MIISN oocyte), the other that ceases development at the 2-cell stage (MIINSN oocyte), with the aim of identifying genes and gene expression networks whose misregulated expression would contribute to a reduced developmental competence. Results We report that: 1) the transcription factor Oct-4 is absent in MIINSN oocytes, accounting for 2) the down-regulation of Stella, a matern…
Stability-Based Model Selection for High Throughput Genomic Data: An Algorithmic Paradigm
2012
Clustering is one of the most well known activities in scien- tific investigation and the object of research in many disciplines, ranging from Statistics to Computer Science. In this beautiful area, one of the most difficult challenges is the model selection problem, i.e., the identifi- cation of the correct number of clusters in a dataset. In the last decade, a few novel techniques for model selection, representing a sharp departure from previous ones in statistics, have been proposed and gained promi- nence for microarray data analysis. Among those, the stability-based methods are the most robust and best performing in terms of predic- tion, but the slowest in terms of time. Unfortunately…
Transience versus recurrence for scale-free spatial networks
2020
Weight-dependent random connection graphs are a class of local network models that combine scale-free degree distribution, small-world properties and clustering. In this paper we discuss recurrence or transience of these graphs, features that are relevant for the performance of search and information diffusion algorithms on the network.
A Study on Engineering Freshman Conceptual Understanding of Newtonian Mechanics
2021
Force concept inventory is a multiple-choice questionnaire commonly used to assess students’ conceptual understanding of Newtonian mechanics. We here show that a cluster analysis method can be used to study student answers to the force concept inventory to investigate their understanding of Newtonian mechanics and provide new insights into the use of the force concept inventory. We identi- fied groups of students characterized by similar correct answers as well as by non- correct answers to the questionnaire, whose analysis allowed us to highlight student misconceptions/non-normative conceptions. Such an analysis of student answers gave us insights into the relationships between the student…
STUDY ON CONSUMERS' BEHAVIOR CONCERNING BERRIES CONSUMPTION IN ITALY
2014
In Italy, the cultivated land of berries shows a positive trend, nevertheless berries still remain a productive segment of niche and luxury in the Italian agri-food system. In the world, the interest for these productions is high for their healthy aspects that have a strong appeal to the consumers. The objectives of this study are to know the consumers behavior of berries and the determinants of purchase in Italy in order to improve the management of the producing and retailers companies for increase the competitiveness of the supply chain. The results obtained through a multivariate analysis show some difference among the consumers interviewed. The most important results of this study is t…
A study on science teaching efficacy beliefs during pre-service elementary training
2020
Two science teaching workshops for students of the elementary teacher education degree course at the University of Palermo, Italy are discussed, one based on inquiry-based methods and the other on "traditional" teaching methods. A questionnaire aimed to understand the teaching styles preferred by students, their reasons for learning/teaching science, and their beliefs about the difficulties a teacher faces when planning and trying out science teaching activities in the class were completed by the students before the first workshop, at its end, and the end of the second workshop. The answers given by the students were studied using cluster analysis methods. The results of the analysis of ans…
Individuazione di cavità attraverso tomografie elettriche e sismiche
2020
Le tecniche geofisiche sono i metodi più efficienti per ottenere informazioni sulle strutture presenti nel sottosuolo. Ad oggi, la tomografia di resistività elettrica (ERT) è il metodo più utilizzato per il rilevamento di vuoti sotterranei, tuttavia, la combinazione con dati derivanti da diversi metodi geofisici è l’approccio più adatto per la determinazione delle cavità. Negli ultimi anni, la ERT è stata sempre più spesso congiunta alla tomografia sismica a rifrazione (SRT) al fine di ottenere interpretazioni più robuste anche utilizzando un approccio di tipo statistico. La cluster analysis eseguita su unità statistiche definite da valori di resistività elettrica, velocità delle onde P e d…