Search results for "ample"
showing 10 items of 2398 documents
Culture as an influence on sexting attitudes and behaviors: A differential analysis comparing adolescents from Spain and Colombia
2020
Abstract This study analyses the prevalence of sexting and the reasons and attitudes associated with its practice in adolescents with different cultural backgrounds (Colombia and Spain). The sample is made up of 489 Spaniards and 510 Colombians aged between 13 and 18 years. The results show that sexting is strongly influenced by gender and the country, in favor of men and Colombians respectively. The interaction between gender and country establishes that in Spain women and men practice sexting equally, while in Colombia men practice much more sexting than women. Although the practice of sexting increases progressively with age, the levels are higher among Colombian adolescents, especially …
A Multi-Projector Calibration Method for Virtual Reality Simulators with Analytically Defined Screens
2017
The geometric calibration of projectors is a demanding task, particularly for the industry of virtual reality simulators. Different methods have been developed during the last decades to retrieve the intrinsic and extrinsic parameters of projectors, most of them being based on planar homographies and some requiring an extended calibration process. The aim of our research work is to design a fast and user-friendly method to provide multi-projector calibration on analytically defined screens, where a sample is shown for a virtual reality Formula 1 simulator that has a cylindrical screen. The proposed method results from the combination of surveying, photogrammetry and image processing approac…
Two‐sample problems in statistical data modelling
2010
A common problem in mathematical statistics is to check whether two samples differ from each other. From modelling point of view it is possible to make a statistical test for the equality of two means or alternatively two distribution functions. The second approach allows to represent the two‐sample test graphically. This can be done by adding simultaneous confidence bands to the probability‐probability (P — P) or quantile‐quantile (Q — Q) plots. In this paper we compare empirically the accuracy of the classical two‐sample t‐test, empirical likelihood method and several bootstrap methods. For a real data example both Q — Q and P — P plots with simultaneous confidence bands have been plotted…
A firm's activity in social media and its relationship with corporate reputation and firm performance
2015
There is growing debate about whether companies’ investments in social media really pay off. This research attempts to contribute to this discussion by investigating the relationship between a firm’s social media activity and two outcomes, namely, company reputation and firm financial performance. Two propositions are developed based on theory and tested with a sample of 59 companies. The findings suggest that a firm’s social media activity is only partially linked with its financial performance and is not linked with corporate reputation. The implications of the research suggest that little is known about the relationships between a firm’s social media activity and corporate reputation and…
Talent Goes Social: Online Corporate Networking and Business Performance
2020
This study examines the effect of online social talent on business performance. The paper uses data from a selected sample of 296 companies from the S&
Testing a new sampler for measuring plot soil loss
2016
In order to measure soil loss in equipped plots the estimate of the weight of solid material intercepted at their lower end is required. At the experimental area of Sparacia, Sicily, the runoff produced by an erosive event is collected within storage tanks with a capacity of about 1m3. In this paper, the use of a new sampler is proposed to measure easily the weight of solid material eroded from an experimental plot and collected into a storage tank. The sampler is a cylinder having a closing valve at the bottom. Two different series of runs were carried out both to test the reliability of the sampler and to establish a sampling procedure, respectively. An analysis of various sampling config…
The ALHAMBRA survey: evolution of galaxy clustering since z∼1
2014
We study the clustering of galaxies as function of luminosity and redshift in the range $0.35 < z < 1.25$ using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover $2.38 \mathrm{deg}^2$ in 7 independent fields, after applying a detailed angular selection mask, with accurate photometric redshifts, $��_z \lesssim 0.014 (1+z)$, down to $I_{\rm AB} < 24$. Given the depth of the survey, we select samples in $B$-band luminosity down to $L^{\rm th} \simeq 0.16 L^{*}$ at $z = 0.9$. We measure the real-space clustering using the projected correlation function, accounting for photometric redshifts uncert…
Determination of glyphosate and its metabolite aminomethylphosphonic acid in fruit juices using supported-liquid membrane preconcentration method wit…
2005
Abstract The application of supported-liquid membrane (SLM) technique for effective extraction of N -(phosphonomethyl)glycine (glyphosate) and its primary metabolite aminomethylphosphonic acid (AMPA) from juices (orange, grapefruit, apple and blackcurrant) in combination with HPLC-UV detection after derivatization with p -toluenesulphonyl chloride (TsCl) is presented. The influence of various parameters such as the composition of acceptor phase, flow-rate, concentration of analytes, on the performance of extraction procedure, was studied. It was shown that by appropriate manipulation of SLM parameters the level of detection could be significantly improved. The influence of SLM conditions on…
Optimisation algorithms in the case of mineral detection using Raman Analysis
2013
Abstract Raman analysis can be used to analyse the existence of minerals in an ore sample. Especially the interest here is to analyse given ore sample rapidly, to find out what minerals it contains. Rapid analysis would enable more rapid exploration of minerals as analysis could be carried out on-site. For this study, ore samples were collected from two mines in Northern Finland, Kittila and Kevitsa. An optimisation algorithm was constructed to form a linear combination of reference spectra which best represent the measured spectrum from an ore sample. The reference spectra were collected from a public source. It was found that solving for an optimal summation of reference spectra can be a …
Carleson's counterexample and a scale of Lorentz-BMO spaces on the bitorus
2005
We introduce a full scale of Lorentz-BMO spaces BMO L p,q on the bidisk, and show that these spaces do not coincide for different values ofp andq. Our main tool is a detailed analysis of Carleson's construction in [C].