Teresa Oliveira

Universidade Aberta · Department of Sciences and Technology (DCeT)

Invitation to the 17th International Conference of Computational Methods in Sciences and Engineering (ICCMSE) Dear colleagues, I have great pleasure in inviting you to participate in the 17th International Conference of Computational Methods in Sciences and Engineering- ICCMSE conference 4 – 7 of September 2021 in Heraklion, Crete, Greece, namely...

Immersive learning research is a field of study that emphasizes diversity of scholarship and subject areas. This diversity presents a challenge for understanding the breadth and depth of the field of immersive learning, a challenge that led to the Immersive Learning Research Network’s call for the community of immersive learning researchers to deve...

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 e...

This work is part of a study about COVID-19 pandemic in Mozambique. Here we reproduce the first part of such study where a general introduction about the background and motivational aspects of COVID-19 in the world is made. Also, the relevance of mathematical and statistical modeling, the concepts of risk, risk analysis and spatial epidemiology are...

During a pandemic, public discussion and decision-making may be required in face of limited evidence. Data-grounded analysis can support decision-makers in such contexts, contributing to inform public policies. We present an empirical analysis method based on regression modelling and hypotheses testing to assess events for the possibility of occurr...

https://www.youtube.com/watch?v=gPcFvpOCqUc

Environmental changes leading to different growth patterns of allergenic species, longer pollen seasons, deterioration of indoor and outdoor air quality have reportedly increased allergic rhinitis and viral infections in children which may lead to facial growth problems. The airway has a relevant role in the development of craniofacial structures,...

This book provides an overview of the role of statistics in Risk Analysis, by addressing theory, methodology and applications covering the broad scope of risk assessment in life sciences and public health, environmental science as well as in economics and finance. Experimental Design plays a key role in many of these areas, therefore there is speci...

Resumo: Nesta palestra os participantes são convidados a viajar pelo mundo da Matemática e da Estatística, numa espécie de trem imaginário, inter-espacial e intemporal, cujas paragens e apeadeiros são ilustradas pela vertente artística que, neste novo século, tem sido amplamente desenvolvida no âmbito do paradigma digital. A Matemática pode ser vis...

Stochastic Response Surface Methodology (SRSM) is very well known as a tool for modeling uncertainty in simulation models, mainly in the context of Risk Analysis. Developments on SRSM were remarkable over the past few years, mainly due to the technological advances and new powerful tools in what concerns hardware and software. It has also been poss...

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The present paper describes an application of Monte Carlo (MC) methods to estimate the sample size under the framework of statistical power (SP) and accuracy in parameter estimation (AIPE), for a multivariate regression analysis on oral health research. The ultimate goal of our research is to create a model to assist in the estimation of the risk o...

The analysis of the product of two normally distributed variables does not seem to follow any known distribution. Fortunately, the moment-generating function is available and we can calculate the statistics of the product distribution: mean, variance, the skewness and kurtosis (excess of kurtosis). In this work, we have considered the role played b...

The estimation of variance components and estimable vectors is carried out for nonorthogonal mixed models. To do that we use a decomposition of the design space in several orthogonal blocks. We assume the random vectors to have null mean vectors and null cross covariance matrices.

Big Data has become the new slang in the world of information collection and analysis. The researches we conduct and the data we collect continue to grow, due to rapidly expansion of technology. Disciplines such as Computer Science, Engineering, and Statistics play a key role in the analysis of big data, each with its specificity but all equally im...

The role of Experimental Design is very well known, considering applications to a broad range of areas, such as Agriculture, Biology, Medicine, Industry, Education, Economy, Engineering and Food Consumption Sciences. Motivated by the variety of problems faced in the several areas and simultaneously taking advantage of the emerging technological dev...

This paper presents a study of the evolution the study of the product of two normally distributed variables. From first approaches in the middle of the 20th Century until the most recent ones from this decade. Nowadays, existence of an unique formula for the product was not proved. Partial results using different approaches: Bessel Functions, Numer...

The distribution of the product of two normally distributed random variables has been an open problem from the early years in the XXth century. First approaches tried to determinate the mathematical and statistical properties of the distribution of such a product using different types of functions. Recently, an improvement in computational techniqu...

This paper presents the perspectives of the immersive learning research network community on the relevance of various challenges to the adoption of immersive learning technology, along three dimensions: access, content production, and deployment. Using a previously validated questionnaire, we surveyed this community of 622 researchers and practitio...

We are pleased to invite you to submit original contributions to ICTCT’20 via the Official Submission System (Springer OCS). Submissions can include technical, experimental, theoretical, conceptual, or survey papers. All Submissions will be peer- reviewed with reference to relevance, originality, importance and clarity. PAPERS PUBLICATION. PROCEED...

In the areas of Computer Science and Telecommunications there is a huge amount of applications in which error control, error detection and error correction are crucial tools to enable reliable delivery of digital data over unreliable communication, thus providing quality of service. Hadamard matrices can almost directly be used as an error-correcti...

Goal: The objective is to conclude, based on a comparative study, if there is a significant difference in sensitivity between the application of MCE and the individual application of the CUSUM or EWMA chart, i.e., greater sensitivity particularly for cases of lesser magnitude of change. Design/Methodology/Approach: These are an applied research an...

The aim of the study was to assess regional income disparities among rural households in Poland in 2005, 2010 and 2015. Simultaneous analysis of changes in affluence and its inequality allowed for a deeper look at the convergence processes in the context of the cohesion policy. The research drew on microdata from the Household Budget Surveys conduc...

This book provides an overview of the latest developments in the field of risk analysis (RA). Statistical methodologies have long-since been employed as crucial decision support tools in RA. Thus, in the context of this new century, characterized by a variety of daily risks - from security to health risks - the importance of exploring theoretical a...

Banks and financial institutions are exposed with credit risk, liquidity risk, market risk, operational risk, and others. Credit risk often comes from undue concentration of loan portfolios. Among the diversity of tools available in literature for risk measurement, in our study the Coefficient of Variation (CV) was chosen taking into account that i...

PADRÕES ARTÍSTICOS COM QUADRADOS LATINOS E GRECO-LATINOS, Teresa A. Oliveira, Universidade Aberta e CEAUL RESUMO: Com este trabalho pretende-se fomentar ligações entre a matemática, a estatística e as artes, tendo por padrão base a figura geométrica quadrado. Começamos por rever o conceito de quadrado ilustrando a sua representação visual, seguida...

Design and analysis of experiments will become much more prevalent simultaneously in scientific, academic and applied aspects over the next few years. Combinatorial designs are touted as the most important structures in this field taking into account their desirable features from statistical perspective.1,2 The applicability of such designs is wide...

We present a method, that uses pivot variables, which are functions of statistics and parameters, of constructing confidence intervals for variance components in gauge capability studies. As illustration we will consider a study on repeatability and reproducibility measures. Besides this the paper includes a simulation study demonstrating that in a...

The existence of Hadamard matrices remains one of the most challenging open questions in combinatorics. Substantial progress on their existence has resulted from advances in algebraic design theory using deep connections with linear algebra, abstract algebra, finite geometry, number theory, combinatorics and optimization. The construction and analy...

Banks and financial institutions are exposed with credit risk, liquidity risk, market risk, operational risk and others. Credit risk often comes from undue concentration of loan portfolios. Among the diversity of tools available in literature for risk measurement, in our study the Coefficient of Variation (CV) was chosen taking into account that it...

The Item Response Theory (IRT) has become one of the most popular scoring frameworks for measurement data, frequently used in computerized adaptive testing, cognitively diagnostic assessment and test equating. According to Andrade et al. (2000), IRT can be defined as a set of mathematical models (Item Response Models – IRM) constructed to represent...

Teaching is a complex mission that requires not only the theoretical knowledge transmission, but furthermore requires to provide the students the necessary skills for solving real problems in their respective professional activities where complex issues and problems must be frequently faced. Over more than twenty years we have been experiencing an...

In this work the probability density function (PDF) for the product of two uniformly distributed random variables is explored under the implementation of a new procedure in R language. Based on the Rohatgi theorem for the theoretical form of the product, different possibilities for the range of values of the limits of both distributions are conside...

The stiffness of paperboard is an important continuous variable measured in the labs of paperboard industry to evaluate the quality of the final product. The variable is approximately normal distributed, in this case study, and individual control charts to monitor the stiffness are obtained based on average moving range. Since the available sample...

Considering the implementation of an Experimental Design, in any field, the experimenter must pay particular attention and look for the best strategies in the following steps: planning the design selection, conduct the experiments, collect observed data, proceed to analysis and interpretation of results. The focus is on providing both - a deep unde...

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Kurtosis (κ) is any measure of the “peakedness” of a distribution of a real-valued random variable. We study the evolution of the Kurtosis for the product of two normally distributed variables. Product of two normal variables is a very common problem for some areas of study, like, physics, economics, psychology, … Normal variables have a constant v...

In food and other manufacturing industries, it is important to control the presence of some chemical substances in the raw material and, in some cases, along the different phases of its production. Indeed, such substances can strongly affect the quality of the final products. To measure the concentration of such substances, chromatography analyses...

How should an insurer price a risk for which there is no history? This work intends to show, step by step, which main mechanisms are needed to capture the tariff model of another insurance company minimizing the risk involved. The document generally deals with the price-making mechanisms in non-life insurance through the GLM regression models — Gen...

The analysis of skewness is an essential tool for decision-making since it can be used as an indicator on risk assessment. It is well known that negative skewed distributions lead to negative outcomes, while a positive skewness usually leads to good scenarios and consequently minimizes risks. In this work the impact of skewness on risk analysis wil...

Francisco, C.; Oliveira, T. apresentam em 2015 o artigo, Combinatorial Designs as a Tool to Recover Information from Damaged QR Codes, na 16th Conference ASMDA Applied Stochastic Models and Data Analysis International Society, Department of Statistics and Insurance Science University of Piraeus. Disponível em http://asmda2015.com

Disponível em https://sites.google.com/site/7themath2015/home

Francisco, C.; Oliveira, T. apresentam em 2015 o artigo, Application of Hadamard Matrices to Information Security, Error Correction and their links to Combinatorial Designs, na 7th International Workshop on Mathematics e-Learning no Porto, Portugal. Disponível em https://sites.google.com/site/7themath2015/home.

Book of Abstracts, Pages: 16 and 311. Disponível em http://www.uoc.edu/portal/en/symposia/icra6/Home/

The microarray technique is a powerful biotechnological tool, expanding in a interesting way the vision with which issues in medicine are studied. Microarray technology, allows simultaneous evaluation of the expression of thousands of genes in different tissues of a given organism, and in different stages of development or environmental conditions....

Risk Analysis has assumed a crucial relevance over the past few years, particularly in dynamical systems with increasing complexity. Thanks to recent technological advances, the use of simulation techniques to estimate models has become the norm rather than the exception. These simulated models are used to predict the behavior of a system, to compu...

http://biostat.cu.edu.tr/emr2015/dosyalar/final_program_book.pdf

This book covers the latest results in the field of risk analysis. Presented topics include probabilistic models in cancer research, models and methods in longevity, epidemiology of cancer risk, engineering reliability and economical risk problems. The contributions of this volume originate from the 5th International Conference on Risk Analysis (IC...

This book covers the latest results in the field of risk analysis. Presented topics include probabilistic models in cancer research, models and methods in longevity, epidemiology of cancer risk, engineering reliability and economical risk problems. The contributions of this volume originate from the 5th International Conference on Risk Analysis (IC...

In this paper we review Stochastic Response Surface Methodology as a tool for modeling uncertainty in the context of Risk Analysis. An application in the survival analysis in the breast cancer context is implemented with R software.

The observation of certain higher chemical element concentration, such as uranium and radiometric values, in the Alegrete-Assumar region of Portugal, has shown that locally occurrence of radioactive quartzites is responsible for these high values. The geostatistical treatment of exploration data and the crossing of the database with other variables...

This paper is a review of Stochastic Response Surface Methodology in the context of Risk Analysis, as a tool for modeling uncertainty on the analysis of simulation models. Some applications are reviewed and an application in the survival analysis is implemented with R software.

Francisco, C.; Oliveira, T. apresentam em 2015 o artigo, Delineamento combinatório e aplicações a códigos de autenticação e segurança de informação: uma abordagem baseada em matrizes de Hadamard, nas 3ªs Jornadas de Matemática da Universidade Aberta‎ em Lisboa, Portugal. Disponível em https://sites.google.com/site/matematicaaberta2015/home/programa...

Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies

Risk is associated with all areas of Life, and studies designed to decrease it play a key role, particularly in what concerns Individual Health. Considering Epidemiological Research, the identification of Risk Factors is crucial to select prevention actions in order to improve Public Health Systems. The aim of this work is to identify the main Risk...

The aim of the present study was to establish comparisons between male adolescent athletes and non-athletes, aged between 15 and 16, belonging to two schools of Barcelos (a city in the North of Portugal), and regarding the following components: 1) body composition, and 2) food intake. The sample was constituted by 118 subjects, of which 40 were ath...

This is the second book devoted to the 3rd Stochastic Modeling Techniques and Data Analysis (SMTDA) International Conference held in Lisbon, Portugal, June 11-14, 2014. Revised and expanded forms of papers from the conference presentations are included. SMTDA main objective is to publish papers, both theoretical or practical, presenting new results...

As a branch of Block Designs, research on Balanced Incomplete Block Designs (BIBD) arose several interesting and defying problems within Combinatory Mathematics. Hadamard Matrices are present in our daily life and it give rise to a class of block designs named Hadamard configurations. It is easy and current to find different applications of it base...

Francisco, C. and Oliveira, T.A. (2014). BIBD, Hadamard Matrices and new technological devices: applications to QR Codes. In T. E. Simos, G.Psihoyios, Ch. Tsitouras and Z. Anastassi (eds.), Numerical Analysis and Applied Mathematics ICNAAM 2014, AIP Conference Proceedings, American Institute of Physics. In Press, 840004; doi: 10.1063/1.4913044. Dis...

AIP Conference Proceedings, American Institute of Physics. In Press. Disponível em http://www.2014.icnaam.org/

Experimental design utilizing blocks was first presented by Ronald A. Fisher in the beginning of the 20 th century with applications in agriculture. It became one of the areas of mass development for research in various fields, from agriculture to medicine, playing a central role not only on the research process but also on the new technological ad...

In water supply systems with distribution networkthe most critical aspects of control and Monitoring of water quality, which generates crises system, are the effects of cross-contamination originated by the network typology. The classics of control of quality systems through the application of Shewhart charts are generally difficult to manage in r...

The amount of periodontal attachment around the tooth is an important prognostic factor for dental treatment planning.The aim of this study is to estimate the quantity of remaining of attachment area of a tooth affected with periodontitis.Ageneralized linear model was fitted to data from mandibular pre-molar teeth scanned a high-resolution micro-CT...

The distribution of the ratio of two normal random variables X and Y was studied from [1] (the density function) and [2] (the distribution function). The shape of its density function can be uni-modal, bimodal, symmetric, asymmetric, following several type of distributions, like Dirac Distribution, Normal Distribution, Cauchy Distribution or Recino...

Disponível em: http://www.up.poznan.pl/cb44/index_en.html

Disponível em: http://stat_am.cpaa.embrapa.br/..

“Statistical and Biometrical Challenges: Theory and Applications” presents selected contributions from the meetings ICRA5 and WSMC7, held 2013 in Tomar, Portugal. The papers in this volume came from experts from around the world and cover latest scientific research into statistical, biometrical and computational methods, including some theoretical...

Francisco, C. and Oliveira. T. A. (2014). Hadamard Matrices and new technological devices: applications to QR Codes. SMSW'14 (Statistics and Mathematical Sciences Workshop), UBI, Covilhã, Portugal. Disponível em: http://smsciencesw.wix.com/smsw.

Francisco, C.; Oliveira, T. A. (2014): BIBD, Hadamard Matrices and Risk Of Data Loss on QR Codes, in Proceedings of SMTDA 2014, 3rd Stochastic Modeling Techniques and Data Analysis, International Conference in Lisbon, Portugal, 11-14 June 2014. Book of Abstracts, 61. Disponível em: http://www.smtda.net/images/Final_BOOK_OF_ABSTRACTS_SMTDA2014.pdf

Book of Abstracts, Page 61. Disponível em: http://www.smtda.net/images/Final_BOOK_OF_ABSTRACTS_SMTDA2014.pdf

Francisco, C.; Oliveira, T. A. (2014): BIBD, Delineamento Experimental em blocos incompletos, in Proceedings of WSMC8 2014, 8th Workshop on Statistics Mathematics and Computation. ISCEE - Instituto Superior de Ciências Económicas e Empresariais, Cidade da Praia, ilha de Santiago, Cabo Verde, 12 a 15 Março 2014. Disponível em: https://sites.google.c...

Poster: Delineamento Experimental em blocos incompletos Disponível em: https://sites.google.com/site/wsmc2014cv/

Disponível em: https://sites.google.com/site/wsmc2014cv/ .

WSMC8 was organized by Universidade Aberta (UAb), Instituto Superior de Ciências Económicas e Empresariais of Cabo Verde (ISCEE), Centro de Estatística e Aplicações da Universidade de Lisboa (CEAUL) and Instituto Politécnico deTomar (IPT). We celebrated this meeting in honour of Professor Christos Kitsos to express with great pleasure our gratitude...

Multivariate statistical analysis is indispensable to assess the associations and interactions between different factors and the risk of periodontitis. Among others, regression analysis is a statistical technique widely used in healthcare to investigate and model the relationship between variables. In our work we study the impact of socio-demograph...

Experimental Designs have been widely used, among others, in agricultural, industrial and computer experiments, in order to reduce experimental cost and to provide efficient parameter estimation. Balanced Incomplete Block Designs (BIBD) play a key role in this context: in addition to their optimal properties and to the possible applications in vari...