Search results for "Sampling"

Development Of An Econometric Model Case Study: Romanian Classification System

2015

Abstract The purpose of the paper is to illustrate an econometric model used to predict the lean meat content in pig carcasses, based on the muscle thickness and back fat thickness measured by the means of an optical probe (OptiGrade PRO).The analysis goes through all steps involved in the development of the model: statement of theory, specification of the mathematical model, sampling and collection of data, estimation of the parameters of the chosen econometric model, tests of the hypothesis derived from the model and prediction equations. The data have been in a controlled experiment conducted by the Romanian Carcass Classification Commission in 2007. The purpose of the experiment was to …

B-Spline Estimation in a Survey Sampling Framework

2021

Nonparametric regression models have been used more and more over the last years to model survey data and incorporate efficiently auxiliary information in order to improve the estimation of totals, means or other study parameters such as Gini index or poverty rate. B-spline nonparametric regression has the benefit of being very flexible in modeling nonlinear survey data while keeping many similarities and properties of the classical linear regression. This method proved to be efficient for deriving a unique system of weights which allowed to estimate in an efficient way and simultaneously many study parameters. Applications on real and simulated survey data showed its high efficiency. This …

Methods to Use Big Wearable Heart Rate Data for Estimation of Physical Activity in Population Level

2015

Technologies for wearable health monitoring are becoming increasingly popular and affordable. As a result, large-scale health databases from a large number of individuals are becoming available. However, analysis of these databases requires special methodology to transform available parameters into more generic ones and to manage such non-balanced data characteristics as biases and sampling issues. In this paper, we introduce a methodology for studying physical activity from big wearable heart rate (HR) data on about 5 000 working-age individuals, each measured only for a few days. Physical activity was assessed by oxygen consumption (VO2) calculated from measured HR data using a neural net…

The errors in ?estimation of errors in mechanical efficiency?

1992

Etna International Training School of Geochemistry, 2018. Science meets practice.

2018

Mount Etna, located in eastern Sicily, is the largest stratovolcano in Europe and one of the most intensely degassing volcanoes of the world (Allard et al., 1991; Gerlach, 1991). In particular, previous estimates highlighted that Mt Etna emits about 1.6 % of global H2O fluxes from arc volcanism (Aiuppa et al., 2008) and 10 % of global average volcanic emission of CO2 and SO2 (D’Alessandro et al., 1997; Caltabiano et al., 2004). Furthermore, Gauthier and Le Cloarec (1998) underscored that Mt. Etna is an important source of volcanic particles, having a mass flux of particle passively released from the volcano during non-eruptive period estimated between 7 to 23 tons/day (Martin et al., 2008; …

Taking Advantage of Selective Change Driven Processing for 3D Scanning

2013

This article deals with the application of the principles of SCD (Selective Change Driven) vision to 3D laser scanning. Two experimental sets have been implemented: one with a classical CMOS (Complementary Metal-Oxide Semiconductor) sensor, and the other one with a recently developed CMOS SCD sensor for comparative purposes, both using the technique known as Active Triangulation. An SCD sensor only delivers the pixels that have changed most, ordered by the magnitude of their change since their last readout. The 3D scanning method is based on the systematic search through the entire image to detect pixels that exceed a certain threshold, showing the SCD approach to be ideal for this applicat…

PACo: a novel procrustes application to cophylogenetic analysis.

2013

We present Procrustean Approach to Cophylogeny (PACo), a novel statistical tool to test for congruence between phylogenetic trees, or between phylogenetic distance matrices of associated taxa. Unlike previous tests, PACo evaluates the dependence of one phylogeny upon the other. This makes it especially appropriate to test the classical coevolutionary model that assumes that parasites that spend part of their life in or on their hosts track the phylogeny of their hosts. The new method does not require fully resolved phylogenies and allows for multiple host-parasite associations. PACo produces a Procrustes superimposition plot enabling a graphical assessment of the fit of the parasite phyloge…

Protocols for UV camera volcanic SO2 measurements

2010

Abstract Ultraviolet camera technology offers considerable promise for enabling 1 Hz timescale acquisitions of volcanic degassing phenomena, providing two orders of magnitude improvements on sampling frequencies from conventionally applied scanning spectrometer systems. This could, for instance enable unprecedented insights into rapid processes, such as strombolian explosions, and non-aliased corroboration with volcano geophysical data. The uptake of this technology has involved disparate methodological approaches, hitherto. As a means of expediting the further proliferation of such systems, we here study these diverse protocols, with the aim of suggesting those we consider optimal. In part…

The relationship between online vigilance and affective well-being in everyday life: Combining smartphone logging with experience sampling

2021

Contains fulltext : 220301.pdf (Publisher’s version ) (Open Access) Through communication technology, users find themselves constantly connected to others to such an extent that they routinely develop a mindset of connectedness. This mindset has been defined as online vigilance. Although there is a large body of research on media use and well-being, the question of how online vigilance impacts well-being remains unanswered. In this preregistered study, we combine experience sampling and smartphone logging to address the relation of online vigilance and affective well-being in everyday life. Seventy-five Android users answered eight daily surveys over five days (N = 1615) whilst having their…

Concurrent and lagged effects of counterdispositional extraversion on vitality

2020

Abstract There are two contrasting perspectives on the effects of state extraversion. One states that people benefit from behaving extraverted, regardless of their level of trait extraversion. The second entails that behaving concordant to one’s trait is natural while deviations from the trait level— counterdispositional behaviors—are effortful to maintain, leading to mental fatigue. We test the possibility that both perspectives are correct, with beneficial effects of high state extraversion showing immediately, while the depleting counterdispositional effects are delayed. Experience sampling data from 67 employees (N = 1,664), shows that extraverted behaviors are associated with high leve…