Search results for "Series"
showing 10 items of 1193 documents
Behaviour of consumers of conventional and organic flowers and ornamental plants in Italy
2013
The paper analyses preferences and motivations of Italian consumers of flowers and ornamental plants, both conventional and organic. The results helped to outline their profile. Purchases are still done in the traditional places (flower shops for cut flowers and plant nurseries for potted plants), however positive trend is found for potted plants purchases at large distribution chains. Some differences came out as to purchase motivations: cut flowers are mainly bought in special occasions whereas potted plants purchases are linked to personal use. The results confirm a positive relationship between the purchase of flowers and plants and the age of the interviewees, besides showing that wome…
Otolith fingerprints reveals potential pollution exposure of newly settled juvenile Sparus aurata
2020
Abstract Coastal ecosystems are increasingly threatened by a wide range of human activities. Fish otolith chemistry, by creating a unique specific signature, can be used as a natural tag for determining life stage dispersal, spatial connectivity and population structure. In this study, we tested whether differences in otolith composition among juveniles of gilthead sea bream, Sparus aurata, could enable their proper allocation to polluted areas based on higher concentrations of elements related to contaminants. Otoliths were embedded, sectioned and analysed by LA-ICP-MS in line scan mode. Multivariate analysis confirmed clear separation between sites and elements. Samples from the site unde…
Historical Suitability and Sustainability of Sicani Mountains Landscape (Western Sicily): An Integrated Approach of Phytosociology and Archaeobotany
2020
Since 2015, the ongoing project &ldquo
A validity and reliability study of Conditional Entropy Measures of Pulse Rate Variability
2019
In this work, we present the feasibility to use a simpler methodological approach for the assessment of the short-term complexity of Heart Rate Variability (HRV). Specifically, we propose to exploit Pulse Rate Variability (PRV) recorded through photoplethysmography in place of HRV measured from the ECG, and to compute complexity via a linear Gaussian approximation in place of the standard model-free methods (e.g., nearest neighbor entropy estimates) usually applied to HRV. Linear PRV-based and model-free HRV-based complexity measures were compared via statistical tests, correlation analysis and Bland-Altman plots, demonstrating an overall good agreement. These results support the applicabil…
Towards a simulation-based tuning of motion cueing algorithms
2016
Abstract This paper deals with the problem of finding the best values for the parameters of Motion Cueing Algorithms (MCA). MCA are responsible for controlling the movements of robotic motion platforms used to generate the gravito-inertial cues of vehicle simulators. The values of their multiple parameters, or coefficients, are hard to establish and they dramatically change the behaviour of MCA. The problem has been traditionally addressed in a subjective, partially non-systematic, iterative, time-consuming way, by seeking pilot/driver feedback on the generated motion cues. The aim of this paper is to introduce a different approach to solve the problem of MCA tuning, by making use of a simu…
Introducing a Fuzzy-Pattern Operator in Fuzzy Time Series
2017
In this paper we introduce a fuzzy pattern operator and propose a new weighting fuzzy time series strategy for generating accurate ex-post forecasts. A decision support system is built for managing the weights of the information provided by the historical data, under a fuzzy time series framework. Our procedure analyzes the historical performance of the time series using different experiments, and it classifies the characteristics of the series through a fuzzy operator, providing a trapezoidal fuzzy number as one-step ahead forecast. We also present some numerical results related to the predictive performance of our procedure with time series of financial data sets.
Forecasting portfolio returns using weighted fuzzy time series methods
2016
We propose using weighted fuzzy time series (FTS) methods to forecast the future performance of returns on portfolios. We model the uncertain parameters of the fuzzy portfolio selection models using a possibilistic interval-valued mean approach, and approximate the uncertain future return on a given portfolio by means of a trapezoidal fuzzy number. Introducing some modifications into the classical models of fuzzy time series, based on weighted operators, enables us to generate trapezoidal numbers as forecasts of the future performance of the portfolio returns. This fuzzy forecast makes it possible to approximate both the expected return and the risk of the investment through the value and a…
Linearized Piecewise Affine in Control and States Hydraulic System: Modeling and Identification
2018
In this paper, the modeling and identification of a nonlinear actuated hydraulic system is addressed. The full-order model is first reduced in relation to the load pressure and flow dynamics and, based thereupon, linearized over the entire operational state-space. The dynamics of the proportional control valve is identified, analyzed, and intentionally excluded from the reduced model, due to a unity gain behavior in the frequency range of interest. The input saturation and dead-zone nonlinearities are considered while the latter is identified to be close to 10% of the valve opening. The mechanical part includes the Stribeck friction detected and estimated from the experiments. The lineariza…
Inferring causation from time series in earth system sciences
2019
The heart of the scientific enterprise is a rational effort to understand the causes behind the phenomena we observe. In large-scale complex dynamical systems such as the Earth system, real experiments are rarely feasible. However, a rapidly increasing amount of observational and simulated data opens up the use of novel data-driven causal methods beyond the commonly adopted correlation techniques. Here, we give an overview of causal inference frameworks and identify promising generic application cases common in Earth system sciences and beyond. We discuss challenges and initiate the benchmark platform causeme.net to close the gap between method users and developers.
Extravascular coagulation in hematopoietic stem and progenitor cell regulation
2018
Abstract The hemostatic system plays pivotal roles in injury repair, innate immunity, and adaptation to inflammatory challenges. We review the evidence that these vascular-protective mechanisms have nontraditional roles in hematopoietic stem cell (HSC) maintenance in their physiological bone marrow (BM) niches at steady-state and under stress. Expression of coagulation factors and the extrinsic coagulation initiator tissue factor by osteoblasts, tissue-resident macrophages, and megakaryocytes suggests that endosteal and vascular HSC niches are functionally regulated by extravascular coagulation. The anticoagulant endothelial protein C receptor (EPCR; Procr) is highly expressed by primitive …