Browsing by Subject "variance"

Now showing 1 - 6 of 6

Access status: Open Access ,
A GIS procedure to assess shoreline changes over time using multi-temporal maps - an analysis of a sandy shoreline in southern Italy over the last 100 years
(Wydawnictwa AGH, 2023) Pepe, Massimiliano; Costantino, Domenica; Alfio, Vincenzo Saverio
The aim of the paper is to identify a methodology capable of assessing shoreline changes through a geomatic approach based on the use of GIS (Geographic Information System) software. The paper describes a case study that reports the evolution of a coastline over a period of more than 100 years using medium and large-scale metric maps available in different periods. In fact, the coastlines were obtained from the source maps of the Italian Cadastre (dated 1890), from numerical cartography available on the coastline and acquired in different period at scales 1:5000 and 1:2000 and, more recently, from the Google Earth Pro platform. To analyse the evolution of the coastline a new procedure has been performed which is based on the use of GIS software, in particular a plugin called DSAS that allows the evaluation of the changes in the coastline and also obtains a statistical analysis of its evolution. The results showed the ease and applicability of the method in determining the evolution of the coastline and the strong erosion of a stretch of coastline with important socio-economic consequences and repercussions was highlighted in the analysed case study.
Access status: Open Access ,
Numeryczne określanie parametrów efektywnych transportu na podstawie cyfrowych obrazów mikrostruktury
(Wydawnictwa AGH, 2010) Różański, Adrian; Łydżba, Dariusz; Sobótka, Maciej
In this work computationally efficient method of effective transport properties determination is proposed. The methodology is applied to digital images of random microstructures. It is shown that effective properties can be evaluated as mean values averaged over sufficient number of samples. The sample is assumed to be a finite-sized region which is a part of digital image. The condition regarding sample size, based on the variance of local volume fraction, is proposed. The variance is shown to be calculated on the basis of two-point probability function. Sample size criterion is verified for two different digital images of random microstructures.
Access status: Open Access ,
On statistical parameters characterizing vibrations of oscillators without damping and forced by stochastic impulses
(Wydawnictwa AGH, 2006) Jabłoński, Marian; Ozga, Agnieszka
Our theoretical study aims at finding the statistical parameters characterizing the vibrations of an oscillator wi-thout damping and forced by stochastic impulses magnitude of the different distribution. We will derive the dependence of these parameters on rigidity and mass of the oscillator and on the stochastic distribution of the impulse magnitude. We will also carry out a numerical simulation verifying the derived mathematical model and interpret the differences between the results obtained in simulation and the mathematical calculations. This study is the first stage of research aimed at designing and calibrating a probe that will facilitate measuring of parameters determining the ąuality of a technological process.
Access status: Open Access ,
Probabilistic characterization of strong convexity
(2011) Rajba, Teresa; Wąsowicz, Szymon
Strong convexity is considered for real functions defined on a real interval. Probabilistic characterization is given and its geometrical sense is explained. Using this characterization some inequalities of Jensen-type are obtained.
Access status: Open Access ,
Probabilistic modeling of mechanical cantilever oscillator fluctuation
(Wydawnictwa AGH, 2023) Kosobutskyy, Petro; Zdobytskyi, Andriy; Marikutsa, Uliana; Melnyk, Mykhaylo; Iwaniec, Marek
The dynamics of oscillations of cantilever-type oscillators have been studied in this work. The probabilistic model of a cantilever is explained. Dependencies for the probability density, mean mathematical expectation, and standard deviation were developed. A fluctuation model of a cantilever was constructed, and the dependencies for the probability density for a direct problem were developed. The modeling of the mathematical expectation and phase variance for the inverse problem was performed.
Access status: Open Access ,
Statistical characteristics of vibrations of a string forced by stochastic forces
(Wydawnictwa AGH, 2008) Jabłoński, Marian; Ozga, Agnieszka
Our theoretical study aims at finding the statistical parameters characterizing the vibrations of a string without damping and forced by stochastic impulses when the places and moments of actions are random. We derive the dependence of these parameters from the parameters of the string as well as from the stochastic distributions of the impulse magnitude, and of the place of the action. We also carry out a numerical simulation verifying the derived mathematical model and interpret the differences between the results obtained in the simulation and the mathematical calculations. This study is the third stage of research aimed at designing and calibrating a probe that will facilitate measuring of parameters determining the quality of a technological process.