Preprinti (MII) / Preprints

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    On Grinbergs' differential geometry and finite fields
    (2019-03-27) Zeps, Dainis
    Emanuels Grinbergs, in his youth, during ten years, from 1933 until 1943, wrote three dissertations on one subject, namely, differential geometry [1, 2, 3]. We think that his work in this direction has been neglected for many years, and it is the last time to try to understand the significance of these works. Here, in this short article we touch only one aspect of this work, and compare and put together two approaches, one from thesis of Grinbergs [3], and another, of the author's, [5, 6], where we show close relation between both.
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    Using 2-colorings in the theory of uniquely Hamiltonian graphs
    (2019-02) Zeps, Dainis;
    We use the concept of 2-coloring in analyzing UH3 graphs and building exact specifications of functions to find new UH3 graphs by Hamiltonian cycle edge extractions
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    About Correctness of Graph-Based Social Network Analysis
    (2017-07-24) Opmanis, Mārtiņš
    Social network analysis widely uses graph techniques. Together with correct applications, in some cases, results are obtained from the graphs using paths longer than one, and due to intransitivity of relationships, several metrics and results are not applicable backward to objects in the investigated domain in a meaningful way. The author provides several examples and tries to recover roots of an incorrect application of graphs.
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    Fragile Correctness of Social Network Analysis
    (2016-11-07) Opmanis, Mārtiņš
    Graph techniques are widely used in social network analysis. However, there are some disputable applications where results are obtained from the graphs using paths longer than one and are not simply applicable to objects in the initial domain. The author provides several examples of such usages and tries to recover roots of an incorrect application of graphs.
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    A systematic review of SQL-on-Hadoop by using compact data formats
    (2016-10-30) Plase, Daiga
    There are huge volumes of raw data generated every day. The question is how to store these data in order to provide faster data access. The research direction in Big Data projects using Hadoop Technology, MapReduce kind of framework and compact data formats shows that two data formats (Avro and Parquet) support schema evolution and compression in order to utilize less storage space. In this paper, a systematic review of SQL-on-Hadoop by using Avro and Parquet has been performed over the past six years (2010–2015) using publications of conference proceedings and journals of IEEEXplore, ACM Digital Library, ScienceDirect. With the help of search strategy followed, 94 research papers have been identified out of which 17 have been analyzed as relevant papers. At the end, the conclusion has been made that direct comparison by compactness and fastness between Avro and Parquet do not exist in data science.