195 research outputs found

    Karlis Poruks - Life in Edmonton

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    Karlis Poruks reminisces about life In Edmonton and his experiences with his granparents and parents and family friends maintenence of the Latvian heritage including speakng Latvian at home, the continuation of Latvian cultural festivals and gatherings as well as latvian handicrafts.16.1 Latvian cultural festivals and celebrations, 15.1.3 Family life in Albert

    Robustness of statistical methods for modeling paired count data using bivariate discrete distributions with general dependence structures

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    Bivariate Poisson models are appropriate for modeling paired count data. However the bivariate Poisson model does not allow for negative dependence structure, therefore it is necessary to consider alternatives, which can produce both positive and negative dependence. A natural way is to consider copulas to generate various bivariate discrete distributions. While such models exist in the literature, the issue of choosing a suitable copula has been overlooked so far. Different copulas lead to different structure, any copula misspecification can render the inference useless. In this work, we consider bivariate Poisson models generated with a copula and investigate its robustness under outliers contamination and model misspecification. Particular focus is given on the robustness of copula related parameters

    Robustness methods for modelling count data with general dependence structures

    No full text
    Bivariate Poisson models are appropriate for modelling paired count data. However, the bivariate Poisson model does not allow for a negative dependence structure. Therefore, it is necessary to consider alternatives. A natural way is to consider copulas to generate various bivariate discrete distributions. While such models exist in the literature, the issue of choosing a suitable copula has been overlooked so far. Different copulas lead to different structures and any copula misspecification can render the inference useless. We consider bivariate Poisson models generated with a copula and investigate its robustness under outliers contamination and model misspecification. Particular focus is on the robustness of copula related parameters. English Premier League data are used to demonstrate the effectiveness of our approach

    Lesins 6

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    Dr. and Mrs. Lesins with family friends, the Poruks at the University of Alberta campus farms, ca 1955. Mirdza Poruks on far left, Mrs. Irma Lesins in white, children Maija and Karlis Poruks, Dr. Karlis Lesins on right

    Robustness methods for modelling count data with general dependence structures

    No full text
    Bivariate Poisson models are appropriate for modelling paired count data. However, the bivariate Poisson model does not allow for a negative dependence structure. Therefore, it is necessary to consider alternatives. A natural way is to consider copulas to generate various bivariate discrete distributions. While such models exist in the literature, the issue of choosing a suitable copula has been overlooked so far. Different copulas lead to different structures and any copula misspecification can render the inference useless. In this work, we consider bivariate Poisson models generated with a copula and investigate its robustness under outliers contamination and model misspecification. Particular focus is on the robustness of copula related parameters. English Premier League data are used to demonstrate the effectiveness of our approach

    A Bayesian model for ranking hazardous sites

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    This paper proposes a methodology to rank dangerous road locations. The model is innovative in two respects. Firstly, it makes use of relevant information per accident location, including the total number of accidents, the number of fatalities, as well as the number of light and severe injuries. Secondly, the model includes a cost function to rank the sites with respect to their total expected cost to the society. Bayesian estimation for the model via a MCMC approach is proposed

    Lesins 5

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    News clipping about Dr. Karlis Lesins, ethnic Latvian and University of Alberta cytogeneticist

    A Bayesian model for ranking hazardous sites

    No full text
    This paper proposes a methodology to rank dangerous road locations. The model is innovative in two respects. Firstly, it makes use of relevant information per accident location, including the total number of accidents, the number of fatalities, as well as the number of light and severe injuries. Secondly, the model includes a cost function to rank the sites with respect to their total expected cost to the society. Bayesian estimation for the model via a MCMC approach is proposed

    Corrigendum: A model for identifying and ranking dangerous accident locations: a case study in Flanders (vol 60, pg 457, 2006)

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    These days, road safety has become a major concern in most modern societies. In this respect, the determination of road locations that are more dangerous than others (black spots or also called sites with promise) can help in better scheduling road safety policies. The present paper proposes a multivariate model to identify and rank sites according to their total expected cost to the society. Bayesian estimation of the model via a Markov Chain Monte Carlo approach is discussed in this paper. To illustrate the proposed model, accident data from 23,184 accident locations in Flanders (Belgium) are used and a cost function proposed by the European Transport Safety Council IS adopted to illustrate the model. It is shown in the paper that the model produces insightful results that can help policy makers in prioritizing road infrastructure investments

    Lesins 4

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    Irma Lesins and Dr. Karlis Lesins on the University of Alberta farms. Dr. Lesins holding Maija Poruks
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