Search results for " statistics"
showing 10 items of 1891 documents
Inland harbours in Central Europe:: Junctions between Northern Europe and the Mediterranean Sea
2016
The international symposium organized in Dijon offers a structural and diachronic comparative analysis of the harbours networks on inland waterbodies. Its goals are the study of the harbours settled on lakes or rivers as a complex phenomenon, and the assessment of their respective significance as hubs in the communication and exchange network between Mediterranean Sea and Northern Europe.These two days gather German, French and European researchers from the different fields required on such a research problem (history, archaeology,geography, palaeoenvironmental analysis, geomatics), in the aim to present recent discoveries and results.The present book contains the 27 abstracts in three lang…
La céramique médiévale et moderne du bassin de la Loire moyenne, chrono-typologie et transformation des aires culturelles dans la longue durée (6e—19…
2022
La présente publication, en accès libre sur Huma-Num, résulte d’un Projet Collectif de Recherche (PCR) sur la céramique médiévale et moderne du bassin de la Loire moyenne qui s’inscrit dans la longue durée, puisqu’il a commencé en 1996 et a déjà fait l’objet de deux suppléments à la RACF (Husi 2003 dir. https://www.persee.fr/issue/sracf_1159-7151_2003_ant1 et Husi 2013 dir. https://journals.openedition.org/racf/1860).Cette publication a comme objectif d’appréhender : (i) la question de la chronologie à partir d’une démarche archéo-statistique originale ; (ii) les questions économiques sociales et culturelles notamment liées aux traditions de fabrication, aux flux et aux échanges de récipien…
Dimension enrichment with factual data during the design of multidimensional models: application to bird biodiversity
2015
20 pages; International audience; Data warehouses (DW) and OLAP systems are technologies allowing the on-line analysis of huge volume of data according to decision-makers’ needs. Designing DW involves taking into account functional requirements and data sources (mixed design methodology) [1]. But, for complex applications, existing automatic design methodologies seem inefficient. In some cases, decision-makers need querying, as a dimension, data which have been defined as facts by actual automatic mixed approachs. Therefore, in this paper, we offer a new mixed refinement methodology relevant to constellation multidimensional schema. The proposed methodolgy allows to decision-makers to enric…
Efficient Computation of Multiscale Entropy over Short Biomedical Time Series Based on Linear State-Space Models
2017
The most common approach to assess the dynamical complexity of a time series across multiple temporal scales makes use of the multiscale entropy (MSE) and refined MSE (RMSE) measures. In spite of their popularity, MSE and RMSE lack an analytical framework allowing their calculation for known dynamic processes and cannot be reliably computed over short time series. To overcome these limitations, we propose a method to assess RMSE for autoregressive (AR) stochastic processes. The method makes use of linear state-space (SS) models to provide the multiscale parametric representation of an AR process observed at different time scales and exploits the SS parameters to quantify analytically the co…
Equivalence of the Pecka–Ponec Correlation Probability and the Statistical F Significance for MLR Models
2004
In an article of this journal Pecka and Ponec [J. Math. Chem. 27 (2000) 13] have proposed, by means of a probability calculation, a method to evaluate the statistical importance of correlations obtained from multilinear regression equations involving an arbitrary number of experimental points and parameters. Here, it is demonstrated how this probability exactly coincides with a more general concept: the confidence probability of an F distribution having the appropriate degrees of freedom.
Multivariate nonparametric tests in a randomized complete block design
2003
AbstractIn this paper multivariate extensions of the Friedman and Page tests for the comparison of several treatments are introduced. Related unadjusted and adjusted treatment effect estimates for the multivariate response variable are also found and their properties discussed. The test statistics and estimates are analogous to the traditional univariate methods. In test constructions, the univariate ranks are replaced by multivariate spatial ranks (J. Nonparam. Statist. 5 (1995) 201). Asymptotic theory is developed to provide approximations for the limiting distributions of the test statistics and estimates. Limiting efficiencies of the tests and treatment effect estimates are found in the…
Pretest-Posttest-Posttest Multilevel IRT Modeling of Competence Growth of Students in Higher Education in Germany
2016
Longitudinal research in higher education faces several challenges. Appropriate methods of analyzing competence growth of students are needed to deal with those challenges and thereby obtain valid results. In this article, a pretest-posttest-posttest multivariate multilevel IRT model for repeated measures is introduced which is designed to address educational research questions according to a German research project. In this model, dependencies between repeated observations of the same students are considered not, as usual, by clustering observations within participants but rather by clustering observations within semesters. Estimation of the model is conducted within a Bayesian framework. …
Role of Social Partners for Work-Based Learning: Results of Surveys
2016
Abstract Introduction of work-based learning (WBL) in Latvia has required new approaches in decision making of different stakeholders. Experience from countries with long-standing WBL tradition has shown the numerous advantages but also the challenges this approach presents. One of these challenges is the need for new forms and mechanisms of cooperation among the key stakeholders – policy makers, public administrators, employers, educators and social partners. The current paper analyses the results of scientific research in this field, as well as uses the empirical results of two surveys performed by the authors: a survey of public sector experts and a survey of employers in Latvia. In orde…
Multivariate factor analysis of Girgentana goat milk composition
2005
The interpretation of the several variables that contribute to defining milk quality is difficult due to the high degree of correlation among them. In this case, one of the best methods of statistical processing is factor analysis, which belongs to the multivariate groups; for our study this particular statistical approach was employed. A total of 1485 individual goat milk samples from 117 Girgentana goats, were collected fortnightly from January to July, and analysed for physical and chemical composition, and clotting properties. Milk pH and tritable acidity were within the normal range for fresh goat milk. Morning milk yield resulted 704 ± 323 g with 3.93 ± 1.23% and 3.…
Influence Functions and Efficiencies of k-Step Hettmansperger–Randles Estimators for Multivariate Location and Regression
2016
In Hettmansperger and Randles (Biometrika 89:851–860, 2002) spatial sign vectors were used to derive simultaneous estimators of multivariate location and shape. Oja (Multivariate nonparametric methods with R. Springer, New York, 2010) proposed a similar approach for the multivariate linear regression case. These estimators are highly robust and have under general assumptions a joint limiting multinormal distribution. The estimates are easy to compute using fixed-point algorithms. There are however no exact proofs for the convergence of these algorithms. The existence and uniqueness of the solutions also still remain unproven although we believe that they hold under general conditions. To ci…