Meshless interface tracking for the simulation of dendrite envelope growth

The growth of dendritic grains during solidification is often modelled using the Grain Envelope Model (GEM), in which the envelope of the dendrite is an interface tracked by the Phase Field Interface Capturing (PFIC) method. In the PFIC method, an phase-field equation is solved on a fixed mesh to track the position of the envelope. While being versatile and robust, PFIC introduces certain numerical artefacts. In this work, we present an alternative approach for the solution of the GEM that employs a Meshless (sharp) Interface Tracking (MIT) formulation, which uses direct, artefact-free interface tracking. In the MIT, the envelope (interface) is defined as a moving domain boundary and the interface-tracking nodes are boundary nodes for the diffusion problem solved in the domain. To increase the accuracy of the method for the diffusion-controlled moving-boundary problem, an \h-adaptive spatial discretization is used, thus, the node spacing is refined in the vicinity of the envelope. MIT combines a parametric surface reconstruction, a mesh-free discretization of the parametric surfaces and the space enclosed by them, and a high-order approximation of the partial differential operators and of the solute concentration field using radial basis functions augmented with monomials. The proposed method is demonstrated on a two-dimensional \h-adaptive solution of the diffusive growth of dendrite and evaluated by comparing the results to the PFIC approach. It is shown that MIT can reproduce the results calculated with PFIC, that it is convergent and that it can capture more details in the envelope shape than PFIC with a similar spatial discretization.Comment: Preprint submitted to Journal of Computational Physic

Children with deficits in particular areas of learning in religious education

V magistrskem delu obravnavam katehezo otrok s posebnimi potrebami, s poudarkom na otrocih s primanjkljaji na posameznih področjih učenja. Kateheti, katehisti in katehistinje se pri poučevanju verouka velikokrat znajdejo v situacijah, ko imajo v večinski skupini veroučencev, ki so večinoma brez dodatnih učnih težav, tudi otroke s posebnimi potrebami – najpogosteje k verouku nemoteno prihajajo otroci s primanjkljaji na posameznih področjih učenja. Taka situacija je pogosta tudi v srednjem šolanju, zato so v raziskavo vključeni tudi profesorji predmeta vera in kultura, ki ga izvajajo na katoliških gimnazijah. Otroci oziroma mladostniki s PPPU imajo na določenih področjih učenja, kot so branje, pisanje, računanje, pravopis izrazito nižje izobraževalne dosežke. Ker v stroki zaenkrat še ne obstajajo specifični didaktično-pedagoški pripomočki za delo z otroki in mladostniki s PPPU, sem ta problem natančneje raziskala, predstavila problematiko in poskusila oblikovati priporočila, ki bi jih pri verskem pouku otrok in mladostnikov v bodoče lahko upoštevali. Trenutno stanje v stroki sem raziskala z vprašalnikom, ki sem ga poslala izbranim katehetom in profesorjem predmeta vera in kultura. Ugotovila sem, da je k večinskemu pouku in verouku vključenih veliko otrok s PPPU (predvsem dislektikov), zanje pa zaenkrat ne obstajajo posebni specifični pripomočki in prilagojena učila. Profesorji in kateheti večinoma obravnavajo snov po zastarelih in neprilagojenih učbenikih, ki prav tako niso več primerni za ostale (vero)učence in dijake zaradi svoje neaktualnosti. Prav tako sem ugotovila, da se v stroki ne organizira dovolj rednih strokovnih izobraževanj, namenjenih specifičnemu delu z otroki in mladostniki s PPPU, oziroma se za taka izobraževanja kaže premalo zanimanja.In my master\u27s thesis I will deal with the catechesis of children with special needs, with an emphasis on children with disabilities in particular areas of learning. Catechists, catechists and catechists often find themselves in situations where children with disabilities - most often children with disabilities in particular areas of learning - are freely attending classes in a large group of believers, mostly without additional learning difficulties. Such children have markedly lower educational attainment in some areas of learning, such as reading, writing, numeracy, spelling. The disorders are as follows: dyslexia (reading disorders), dysortography (spelling problems), dyscalculia and specific artymetric learning difficulties (numeracy disorders), dysgraphia (writing disorders), non-verbal learning disorders, and dyspraxia (a deficit in practical and social skills). These disorders also often occur with neurological developmental disorders (ADHD, ADD, communication disorders, developmental coordination disorders, autism spectrum disorders) and other mental disorders (anxiety, depressive and bipolar disorders). Quite a few such students can attend a school with a personalized program, where they usually attend a class with the younger ones, and attend religious classes with their generation, quickly revealing a gap between the students\u27 abilities and learning goals and those of other religious students. Since there are no specific didactic-pedagogical recommendations for the treatment of children with special needs in the field of expertise, I will investigate this problem more closely, present the problem and try to formulate recommendations that would be taken into account in the teaching of the teaching of children with deficits in individual teaching fields in the future. I will investigate the current situation in the field with a short questionnaire to send to selected catechists and professors of the subject Religion and Culture at Diocesan High Schools in Slovenia, in order to find out how teachers adapt themselves to children and what tools and adjustments they already use

The prediction of landslide movements with artificial neural networks

The thesis deals with the problem of the prediction of landslide movements with artificial neural networks (ANN). At the beginning of the thesis the landslides are introduced in general and especially the Macesnik landslide. Later on geodetic methods for observing movements of landslides are described from referential geodetic methods to geodetic methods for mass collection. The list of content of the project is proposed, which should be used for geodetic observations of the Macesnik slide. The description of all past geodetic observations of the Macesnik slide is given and analysis of the effect of rainfall on the landslide movements is presented. In the fifth part artificial neural networks are presented, the training principles of artificial neural networks and a detailed explanation of artificial neural network with error back propagation algorithm. In the experimental part we have presented the use of artificial neural networks for the prediction of landslide movements. It is shown that the use of ANN can be a successful alternative to other methods, which require thorough geological, hydrological and geomechanical evaluation. It is usual for landslides that none of influential factors alone can reliably explain the sliding mechanism of the slope. Also, with statistical tools it is difficult to correctly determine dependency between individual influential factors. To use artificial neural networks we do not need to know all influential factors and we also d

Query Optimization in ElasticSearch

In the graduation thesis, I present database, its history of origin, and where it is placed from the perspective of cases of use on the software market. I make a short overview of examples of use from the real world, and shortly research trends of its popularity compared to related products and market as a whole. Based on my own experience, literature, official documentation, and experience of other users, I examine the cases which caused problematic operation of the database. For each of the cases I examine the possibility and advisability of solving the problem with automatic optimisation of queries. I examine the case also historically, since Elasticsearch has in the last year significantly changed. I note that automation of queries is not advisable, since the developers in Elasticsearch solved most of the cases with architectural changes, internal optimisation, and a change of query language, which takes away from the user ambiguity in expressing the queries. I establish that the most important feature of well-functioning cluster is a proper size of shards, which cannot be easily changed. For that, an experimental planning of activities is necessary, which I also describe. In addition to optimum size of shard, there are some bad practices, which I also describe in the thesis; with them we can collapse cluster, and it is important that they are known by the user