Search results for "multivariate statistics"
showing 10 items of 290 documents
Multivariate exponential smoothing: A Bayesian forecast approach based on simulation
2009
This paper deals with the prediction of time series with correlated errors at each time point using a Bayesian forecast approach based on the multivariate Holt-Winters model. Assuming that each of the univariate time series comes from the univariate Holt-Winters model, all of them sharing a common structure, the multivariate Holt-Winters model can be formulated as a traditional multivariate regression model. This formulation facilitates obtaining the posterior distribution of the model parameters, which is not analytically tractable: simulation is needed. An acceptance sampling procedure is used in order to obtain a sample from this posterior distribution. Using Monte Carlo integration the …
The Human Biodiversity in the Middle of the Mediterranean. Study of native and settlers populations on the Sicilian context
2020
[IT] Negli ultimi 200.000 anni, la specie umana si è diffusa in tutta la Terra, adattando la sua morfologia e fisiologia a un'ampia gamma di habitat. Lo scheletro umano ha quindi registrato i principali effetti ambientali e di conseguenza i reperti scheletrici assumono grande importanza nell'indagine dei processi evolutivi. Oggi le moderne tecniche di indagini quantitative delle principali caratteristiche morfologiche consentono di metterle in relazione con la variabilità genetica. La posizione geografica della Sicilia, l'isolamento e la sua lunga e dinamica storia di colonizzazione (diversi e numerosi contributi culturali e biologici) hanno creato un contesto peculiare che consente uno stu…
Revised risk estimation and treatment stratification of low- and intermediate-risk neuroblastoma patients by integrating clinical and molecular progn…
2014
Abstract Purpose: To optimize neuroblastoma treatment stratification, we aimed at developing a novel risk estimation system by integrating gene expression–based classification and established prognostic markers. Experimental Design: Gene expression profiles were generated from 709 neuroblastoma specimens using customized 4 × 44 K microarrays. Classification models were built using 75 tumors with contrasting courses of disease. Validation was performed in an independent test set (n = 634) by Kaplan–Meier estimates and Cox regression analyses. Results: The best-performing classifier predicted patient outcome with an accuracy of 0.95 (sensitivity, 0.93; specificity, 0.97) in the validation coh…
Multivariate independent prognostic factors in endometrial carcinoma: A clinicopathologic study in 181 patients
2003
The aim of this study was to evaluate the biologic outcome of endometrial carcinomas as compared to clinical and pathologic parameters and to identify multivariate independent prognostic factors. Charts were abstracted from patients with endometrial carcinoma from 1985 to 1995. Data on clinicopathologic variables, adjuvant treatment, site of recurrence, and survival were collected. χ2 test was used to test association between variables. Kaplan-Maier method was used for survival analysis and Cox proportional hazards model for multiple regression analysis. Univariate analysis revealed that FIGO stage, tumor grade, depth of myometrial invasion, biochemical analysis of progesterone receptor sta…
Study Approaches in Higher Education Mathematics : Investigating the Statistical Behaviour of an Instrument Translated into Norwegian
2019
The revised two-factor study process questionnaire (R-SPQ-2F) has widely been considered valid and reliable in many contexts for measuring students&rsquo
Early human peopling of Sicily: Evidence from the Mesolithic skeletal remains from Grotta d'Oriente
2010
The site of Grotta d'Oriente, Island of Favignana, Sicily has yielded the complete skeleton of an adult female (OB) dated to the Mesolithic age. The cranial morphometry of this individual can provide us with some useful information about the peopling of Sicily in the Early Holocene period.Morphological affinities of OB and other Sicilian Mesolithic specimens were assessed to verify hypotheses concerning the early peopling of Sicily.Craniofacial metric data were employed in a comparative analysis with European Upper Palaeolithic (UP), Mesolithic, Neolithic, and Copper/Bronze age samples, and contemporary Italians. Both a model-free and a model-bound approach were used not only to calculate c…
It is time to abandon “Expected bladder capacity.” Systematic review and new models for children's normal maximum voided volumes
2013
Background There is an agreement to use simple formulae (expected bladder capacity and other age based linear formulae) as bladder capacity benchmark. But real normal child's bladder capacity is unknown. Aims To offer a systematic review of children's normal bladder capacity, to measure children's normal maximum voided volumes (MVVs), to construct models of MVVs and to compare them with the usual formulae. Methods Computerized, manual and grey literature were reviewed until February 2013. Epidemiological, observational, transversal, multicenter study. A consecutive sample of healthy children aged 5–14 years, attending Primary Care centres with no urologic abnormality were selected. Particip…
Multivariate equivalence tests for use in pharmaceutical development.
2014
Statistical equivalence analyses are well-established parts of many studies in the biomedical sciences. Also in pharmaceutical development and manufacturing equivalence testing methods are required in order to statistically establish similarities between machines, process components, or complete processes. This article presents a choice of multivariate equivalence testing procedures for normally distributed data as generalizations of existing univariate methods. In all derived methods, variability is interpreted as nuisance parameter. The use of the proposed methods in pharmaceutical development is demonstrated with a comparative analysis of dissolution profiles.
Combining Real-Time Segmentation and Classification of Rehabilitation Exercises with LSTM Networks and Pointwise Boosting
2020
Autonomous biofeedback tools in support of rehabilitation patients are commonly built as multi-tier pipelines, where a segmentation algorithm is first responsible for isolating motion primitives, and then classification can be performed on each primitive. In this paper, we present a novel segmentation technique that integrates on-the-fly qualitative classification of physical movements in the process. We adopt Long Short-Term Memory (LSTM) networks to model the temporal patterns of a streaming multivariate time series, obtained by sampling acceleration and angular velocity of the limb in motion, and then we aggregate the pointwise predictions of each isolated movement using different boosti…
A Multisite-Multipollutant Air Quality Index
2013
Abstract In this paper, starting from a multivariate spatio-temporal array, containing air pollution data collected for the main pollutants at different monitoring sites over a 1-year period, a new approach is proposed to get a Multipollutant-Multisite Air Quality Index (AQI) time series. A two steps aggregation, related to space and to pollutants, is considered. For the first aggregation (spatial synthesis) a PCA is performed on data array opportunely rearranged, while the index I2, proposed in Ruggieri and Plaia (2011) , is used for the second aggregation (pollutant synthesis), obtaining the new index I 2 MS . Daily data of four air pollutants from the city of Palermo (Italy) are analyzed…