57 documents found, page 1 of 6

Geometrical and optimizations aspects for approximating the response surface in...

The target of this paper is to discuss an approximation when the experimentalist tries to explore the response surface of his industrial experimentation. Different methods under different designs, have been proposed for Response Surface Methods (RSM). We discuss such designs under a geometrical point of view when the optimal response surface is tried to be estimated. A number of applications in RSM are included.

Tail-adaptive generation of random numbers from a gamma-order normal distributi...

The Ziggurat algorithm is a well-established rejection-sampling method designed for the efficient generation of pseudo-random numbers from unimodal distributions, particularly the standard normal. In this work, we extend and adapt the Ziggurat algorithm to enable the tail-adaptive generation of random numbers from the gamma-order generalized normal distribution |a flexible family characterized by a tail-shaping...

Provas de Agregação em Matemática: lição, relatório e curriculum

Exploring forms of disaggregating Covid-19 data: an example

COVID-19 data provided by Portuguese public health authorities lack consis tency in periodicity and metrics. To facilitate time series analysis, we transformed those data to achieve homogeneous periodicity and metrics. We present one method we used and assess the potential introduced bias and its impact on spatial distribution models of COVID-19 in Portugal, using spatial and non-spatial models. Comparing model...

Impact of the COVID-19 pandemic on the financial situation of rural and urban h...

The COVID-19 pandemic not only caused a global health crisis but also had a huge impact on household finances. This research aimed to examine the financial situation of rural and urban households in Poland between 2018 and 2022 from a multidimensional perspective. In a unidimensional approach, the financial situation of households was analyzed separately for their income, expenditures, savings rate, and shares ...

Application of information geometry in incomplete block designs: towards statis...

Program Book: 2023 IMS International Conference on Statistics and Data Science ...

In response to the call from the 2021 IMS (Institute of Mathematical Statistics) Survey report to expand membership from emerging areas of data science, underrepresented groups, and from regions outside of North America, the IMS has launched the annual IMS International Conference on Statistics and Data Science (ICSDS). Following the success of 2022 ICSDS in Florence Italy, December 13-16. 2022, the second and ...

A new R-function to estimate the PDF of the product of two uncorrelated normal ...

This paper analyses the implementation of a procedure using the software R to calculate the Probability Density Function (PDF) of the product of two uncorrelated Normally Distributed Random Variables. The problem of estimating the distribution of the product of two random variables has been solved for some particular cases, but there is no unique expression for all possible situations. In our study, we chose Ro...

Big data sets in environmental studies

Big Data datasets for environmental studies play a crucial role in understanding, monitoring and addressing large-scale environmental issues. Big Data datasets for environmental studies deal with huge volumes of data coming from various sources such as satellites, remote sensors, weather stations, sensor networks and mobile devices. These datasets include detailed information on climate change, biodiversity, ai...

Modeling water level fluctuation in river basins using singular spectrum analysis

Water scarcity affected 29% of the EU territory during at least one season in 2019. In the face of climate change, it is very important to understand the risk of water scarcity. Water scarcity is becoming a growing problem in southern European countries, such as Portugal. In 2019, Portugal, faced one of the most significant water scarcity conditions in the EU-27 on the seasonal scale (seasonal WEI 66%).The main...