Pravdepodobnosť v príkladoch

E-book

Ľubomír Antoni-Stanislav Krajči

An important part of theoretical computer science is the problem of Turing machines. This computational model has two basic properties: like any other computational program, the software of a Turing machine is composed of instructions, but in its case they are all of a single type. Every other (so far known) computer program can be transformed into a Turing machine program without loss of information. While the second feature reduces the question of what a calculator cannot do to the question of what a Turing machine cannot do, the first feature allows a much simpler investigation of such a question. Using this computational model, we can thus find concrete problems that no automaton can ever deal with (perhaps the most famous is the problem of the Turing machine stopping). Their existence demonstrates the fundamental limitations of (not only ideal) computational means, and thus encourages both criticality and humility in our thinking.

Download e-book for free (pdf)

 Matúš Harminc 

Tento učebný text je určený poslucháčom medziodborového štúdia v kombináciách s matematikou, jednoodborového štúdia matematiky ako aj rozširujúceho štúdia matematiky. Je za-meraný na kvadratické kongruencie a niektoré diofantovské rovnice.

Autor

E-book

Karel Saksl

Solving crystal structures is the royal discipline of X-ray crystallography. Its primary task, with the exception of defects, is to describe the atomic structure of the motif that, by its repetition, fills the volume of the entire crystal or crystalline phase. This task is nowadays more or less routine for single-crystal X-ray diffraction, which can locate hundreds to thousands of non-hydrogen atoms in large unit cells. However, in real practice, we often have material available only in powder form instead of single crystals. Solving the atomic structure from its X-ray diffraction data is non-trivial, mainly because the three-dimensional diffraction space of a single crystal is reduced to one dimension by measuring a large number of randomly oriented microcrystals (crystallites). Therefore, the solution itself requires, in addition to proper measurement methodology, the selection of suitable tools, procedures, and strategies that, through optimization, will lead to the solution and refinement of the given crystalline phase. The current limit of this method is approximately 100 non-hydrogen atoms in the asymmetric part of the unit cell, which, however, is sufficient for most inorganic materials.

The goal of these educational texts is to provide students in the second and third levels of university studies with specific guidance on solving crystal structures from powder X-ray diffraction data. These scripts build upon my first monograph and require practical knowledge of its content. Similar to my previous monograph, I offer solved examples without a deep theoretical introduction, demonstrating procedures and strategies leading to the correct solution of crystalline phases using the freely available GSAS-II program. The examples are arranged from simpler to more complex, and the reader will find many useful pieces of information in the literature references as well as in the comments below the line. Part of these scripts are data intended for your individual practice of the described procedures. 

Karel Sakls

Download the e-book for free  (pdf)

E-publication

Soňa Király

The Book of Abstracts of The 9th International Conference on Novel Materials Fundamentals and Applications, NFA 2025, contains 46 contributions from the participants of this conference. This congress is primarily focused on novel materials, ranging from theory to practical applications, with the aim of demonstrating how fundamental discoveries can lead to innovative implementations. All contributions are inspiring and professionally prepared.

Download the e-book for free (pdf)