Analýza obsahu webových diskuzních fór jako zdroj dat pro výzkum nových trendů v užívání psychoaktivních látek ve srovnání s daty získanými od jiných populací Mgr. Eva Drápalová ABSTRACT Background: One of the most significant new trends in substance abuse today is an unprecedented rate of new psychoactive substances (NPS) emergence on a global drug market. While collection of scientific data about the effects and risks of numerous NPS is a timely process, the substantial amount of information about the very same substances is being exchanged on drug discussion forums, creating a pool of data with a potential for research of the NPS trend. Aims: This dissertation aims to evaluate a potential of internet discussion forum content analysis methods by (i) describing and comparing the characteristics of discussion forum visitors to NPS users who do not visit such forums; and subsequently by comparing the internet forum content analysis results describing (ii) a prevalence of NPS use, (iii) effects and context of NPS use and (iv) discussed internet retailers selling NPS with data retrieved by other methods. Methods: Differences between two groups of internet survey respondents were analyzed using Pearson Chi-square and Student's t-test to address the first aim of this dissertation. Furthermore the results of both...

This thesis is devoted to the problem of finding a suitable geometrical de- scription of the domain for the Finite Element Method (FEM). We present the most important methods used in generation and improvement of unstructured triangular meshes (grids) for two dimensional FEM. Possible measures of mesh quality are discussed with respect to their usage in linear Lagrange FEM. The relationship between mesh geometry (especially angles of particular triangles), discretization error and stiffness matrix condition number is examined. Two methods of mesh improvement, based on Centroidal Voronoi Tessellations (CVT) and Optimal Delaunay Triangulations (ODT), are discussed in detail and some results on convergence of CVT based methods are reviewed. Some aspects of these methods, e.g. the relation between density of boundary points and interior mesh vertices and the treatment of the boundary triangles is reconsidered in a new way. We have implemented these two methods and we discuss possible im- provements and new algorithms. A geometrically very interesting idea of recent alternative to FEM, Isogeometric Analysis (IGA), is outlined and demonstrated on a simple example. Several numerical tests are made in order to the compare the accuracy of solutions of isotropic PDEs obtained by FEM on bad mesh, mesh improved...

Czech and Vietnamese are the national languages of the Czech Republic and Vietnam, re- spectively. The distinctive features and the shortage of resources renders Czech-Vietnamese machine translation into a difficult task, leading to the fact that no effort has been put into developing a translation tool specifically for the language pair. In this thesis, we develop phrase-based statistical machine translation systems for the language pair and investigate the potential to improve the translation quality with pivoting. Pivoting refers to a set of ma- chine translation approaches through which a natural language, called pivoting language, is introduced to solve the problem of data scarcity between source and target languages, one of the most challenging problems of statistical machine translation. Selecting English as the sole pivoting language for Czech-Vietnamese translation, we prepare training and test- ing corpora for the three language pairs. All possible corpus sources are explored regarding each specific language pair. The next step is to improve quality of the training corpora through normalizing and filtering. Various experiments with pivoting methods are carried out to analyse the performance of pivoting methods in a realistic working condition.

My paper work deals with the 3D active triangular method of building reconstruction. First, there was a measuring triangular system created. Then the way of its automatic calibration was proposed and consequently also performed. Also algorithms for the automatic detection of the sample projected were proposed. Algoriths were presented with several sample buildings. The result of these algorithms are 3D models of individual buildings. In the end achieved results nd restrictions of the system proposed were assessed.

The paper describes basic principles of the finite element method. Further, basic properties of triangulation are discussed. The thesis is primarily focused on the Delaunay and Greedy triangulation. Greedy triangulation is simple to implement, but may not produce the optimal shape of triangles. Delaunay method is used due to its robustness in a wide range of fields especially in computer graphics. This method is relatively easy to implement and provides triangles with high quality.

The aim of this thesis is to propose methods for obtaining the additional vehicle parameters from the real-world traffic situations images and including existing information of the license plate and localization of the vehicle in the scene. The task is to use an existing installation of the camera systems based on data obtained from these devices to propose a new method of extraction of other vehicle's parameters. Solutions can be divided into two groups: 1. Methods for obtaining the features and methods of data evaluation which will lead to a vehicle's type identification based on a single image of the vehicle. 2. Methods for obtaining data of the vehicle's shape based on image sequence of passing vehicle.

This thesis deals with segmentation of tennis player´s body parts for analysis its motion. Testing code was written in C++ with use of OpenCV library. Some image processing techniques such as thresholding, background subtraction or finding the largest contours were implemented. There was used a linear triangulation technique for calculating the 3D coordinates of segmented points.

The goal of this diploma work is to study the problems of wireless sensor networks. Describe elements of sensor network and discuss how the individual sensor nodes communicate with each other. Find the way how it would be possible to determine the possition of the new added sensor node or mobile sensor node in the sensor network. The selected one algorithm of determining the possition of the sensor node will be implemented in diploma thesis. Algorithms for determining the positions of sensor nodes are divided into groups by using the methods. Selected algorithm will be tested in simulation on chosen platform.

Mobile robotics has been very discussed and wide spread topic recently.   This due to the development in the computer technology that allows us to create   better and more sophisticated robots. The goal of this effort is to create robots   that will be able to autonomously move in the chosen environment. To achieve this goal,   it is necessary for the robot to create the map of its environment, where   the motion planning will occur. Nowadays, the probabilistic algorithms based   on the SLAM algorithm are considered standard in the mapping in these times.   This Phd. thesis deals with the proposal of the motion planning of the robot with   stereocamera placed on the pan-and-tilt unit. The motion planning is designed with   regard to the use of algorithms, which will look for the significant features   in the pair of the images. With the use of the triangulation the map, or a model will be created.     The benefits of this work can be divided into three parts. In the first one the way   of marking the free area, where the robot will plan its motion, is described. The second part   describes the motion planning of the robot in this free area. It takes into account   the properties of the SLAM algorithm and it tries to plan the exploration in order to create   the most precise map. The motion of the pan-and-tilt unit is described in the third part.   It takes advantage of the fact that the robot can observe places that are in the different   directions than the robot moves. This allows us to observe much bigger space without   losing the information about the precision of the movements.

The dissertation thesis aims to identify and describe the key theoretical and methodological problems related to the study of conversation markers and to the collection of authentic data for such an analysis. To illustrate the whole research process, the Argentinian conversation marker boludo as a model example is used. The starting point of the analysis is located at the intersection of conversation analysis, discourse analysis and sociolinguistic paradigms, while taking into account the omnipresent background of pragmatics as well. We try to assess the contribution of such an interdisciplinary approach when studying conversation markers. As for the methodology, the thesis seeks to show what difficulties arise when carrying out a sociolinguistic research of conversation markers, which are understood as units typical of spontaneous conversation, i.e. without external manipulation, in comparison with the variationist research at other language levels. In addition, we also clarify why it is important to evaluate their character not only on the grounds of qualitative and functional perspective (in relation to analysing the socially-indexed interaction markers), but also quantitatively with regards to selected social variables that appear to be relevant for the recurrent use of the given marker. The outcome of the method assessment is an attempt to design a model approach to be applied in practice. In sum, the core of the research consists in analysing the Argentinian marker boludo from different perspectives; namely, within the pragmatic, functional-positional, interactional-sociolinguistic and variationist-sociolinguistic frameworks. Its nature is subsequently compared to the behaviour of another recurrent Argentinian conversation marker, che, since some authors regard them as equivalents. The analyses of naturally-occurring conversation data collected in situ are complemented by introspective judgements of several native speakers.