Digital signature

Digitálního podpisu, které je námětem této semestrální práce, je v současnosti velmi aktuální. Se stále vzrůstajícími možnostmi internetu a vidinou snižující se četnosti používání papírové dokumentace bylo nutné vyvinout metodu podepisování virtualizovaných dokumentů, která by byla stejně nenapadnutelná a bezpečná jako vlastnoruční podpis. Metoda nese název digitální podpis. V práci se zaměříme se na vysvětlení základních pojmů souvisejících s digitálním podpisem, vysvětlením základních pojmů s ním souvisejících jako je certifikát, certifikační autorita, autentizace, ale zejména na základní šifrovací algoritmy a aplikace, dále pak na aplikace ve kterých se digitálního podpisu využívá, například poštovní servery či elektronické bankovnictví. V závěru práce se pokusíme zhodnotit přínos digitálního podpisu a jeho nevýhody. Tato práce si neklade za cíl podat detailní popis procesů šifrování dat, jejím cílem je seznámit přehlednou a srozumitelnou formou širší i nezasvěcenou veřejnost s danou problematikou.Digital signature, the subject of this semester paper, is nowadays very up-to-date. The still rising capabilities of the internet and the vision of lowering the amounts of paper documentation made it necessary to develop a way of signing documents which are transferred through the internet. This is supposed to be equally safe and unassailable as the handwritten signature. This method is called the digital signature. The paper focuses on the explanation of the essential terms connected to digital signature, such as certificate, certification authority, authentication, but in particular on the elementary cryption algorithms, further on applications that make use of digital signature, e.g. post services and electronic banking. In the final chapter, the positive and negative aspects of the electronic signature are discussed.

User Interface for Gathering Quotations

V dnešní době je kladen velký důraz na grafické uživatelského rozhraní. Návrh takového rozhraní obsahuje několik etap. Před samotným návrhem aplikace je důležité si uvědomit, pro koho a za jakým účelem rozhraní vytváříme. Chceme-li, aby se náš návrh stal úspěšným, měli bychom znát a využívat moderních trendů při jeho tvorbě. Je kladen velký důraz na jednoduchost, přehlednost a intuitivnost.There is a huge emphasis on graphical user interfaces today. Design of these interfaces compounds of several stages. First thing to do is to find out, whose for is it and what is the purpose of the interface. We should use modern trends to advance our user interface and to be succesfull with it. There is a hudge importance of simplify, intuitiveness and overal lucidity.

Digital Filter Design on GPU

Tato práce ukazuje jeden z přístupů k návrhu digitálních filtrů s nekonečnou impulzní odezvou a volitelným řádem. Prezentované řešení je založeno na evolučním genetickém algoritmu a umožňuje tedy přímý návrh filtru dle jeho specifikací. Hlavním přínosem práce je paralelní implementace genetického algorimu, která je akcelerovaná pomocí GPU. Filtry jsou navrhovány v kaskádové reprezentaci. Řešení také umožňuje specifikovat požadovanou jak frekvenční, tak fázovou charakteristiku filtru.This thesis shows one of the approaches to the design of ditigal filters with infinite impulse response and specified order. The proposed solution is based on an evolutionary genetic algorithm and therefore allows for direct filter design from its specification. Its main contribution to this subject is that the implementation is parallel and it is acceleraded by GPU. The filters are designed in cascade representation. It also allows to specify both, the desired frequency and phase characteristics of filters.

Cutting ceramics

Bakalářská práce je zaměřena na řeznou keramiku, která patří do nástrojových materiálů. První část se zabývá rozdělením, použitím a charakteristikou základních materiálů pro řezné nástroje. V druhé části se důkladně rozebírá samotná řezná keramika z pohledu historie, výchozích materiálů, výroby, fyzikálních, mechanických vlastností a mikrostruktury. Následuje poslední část, která obsahuje sortiment firem CeramTec, Greenleaf a Saint-Gobain.The Bachelor Thesis is focused on cutting ceramics which belongs to tool materials. The first part deals with sorting, application and characterization of basic materials for cutting tools. The cutting ceramics itself is thoroughly analysed from a historical perspective, default materials, production, physical and mechanical qualities and microstructure in the second part. The last part contains the assortment of CeramTec, Greenleaf and Saint-Gobain.

A LONGITUDINAL STUDY OF THE TAKE-OFF AND TRANSITION PHASE IN SKI-JUMPING AT INTERSPORTTOURNEE INNSBRUCK 1992-1994

The ski-jump is realized in a very variable external conditions influenced by differences in the jumping hill constructions, approach velocities, surfaces (snow, mat, ceramic) and climatic conditions. The take-off phase is also determined by many other factors relating to the structure of movement abilities of individuals and their specific personal patterns of the take-off. The body dimensions can also influence the pattern of the take-off in the last period (it is characterized e.g. by a very low values of Rohrer’s Index, RI = 1.07 - 1.15 by the best jumpers). The change of flight position to the "V" style in the last 2-3 years can also be the factor which could influence the realization of the take-of f . The previous suggestions bring about following questions: - What does the present pattern of the take-off and transition phase look like ? - Are there any differences in the pattern of the take-off and transition phase in the last three-year period ? The event of the World Cup Intersporttournee Innsbruck is a very suitable opportunity to solve this problem. Here the set of all the best world athletes regularly take part on the same date (January 4) each year. During the last three years 1992, 1993, and 1994 the take-off and transition phase being taped at the same position of the cameras in the terraine. By using of the programme package The System of Kinematic Analyses of Ski-jumping, which was developed in our Laboratory, the 2-D analyses were realized for both observed phases. The set of angle and speed parameters describe the anal zed phases. From the sets of all athletes in 't1he rounds (n = 50 - 60) the sets of the best present jumpers (n = 15) were selected according to the length of jump. The statistical analyses were realized for the whole set of the lSt round athletes (correlation and factor analyses) and for the selected sets of the best jumpers. The comparison of the results from different periods of the complete and selected sets of athletes was the starting point for the solution of our problem

COMPARISON OF THE FORCE-TIME STRUCTURE OF THE VERTICAL JUMP BETWEEN MEN AND WOMEN

INTRODUCTION The vertical jump is a relatively simple movement situation which is very ofkn used for the study of the performance in take-off activities, quality of the muscles, coordination of the movement etc. (e.g. Komi & Bosco, 1978; Bobbert, F. M.,1988; Sanders, R. H., 1992,1993 and others). The vertical jump can be used as a very suitable model for the solution of many problems in sport pedagogy, effectiveness of the training process and studying of the movement quality of man. The object of our research is not only the final performance, (i.e. final characteristic of the jump - height of jump), but we are interested in the course of the movement, timing, stability - reproducibility of the movement and other aspects. This study was a part of a larger research project. The main goal of this study is to focus on the following questions: What was the inter-individual variability of the structure of the vertical jump? How was the stability (reproducibility) of the movement during the vertical jump? What were the differences in the structure of the vertical jump between the men and women? The classical counter-movement vertical jump was at the center of our interest. Students of physical education - men (n = 54, body height = 178.40 ± 6.12 cm, body weight = 70.29± 6.36 kg, age = 18 - 20 years) and women (n = 47, body height = 8.48± 6.20 cm, body weight 9.72 ± 6.44 kg, age = 18-20 years) were the subjects of the research. They performed two counter-movement vertical jumps. The vertical component Fz was registered by using the KISTLER platform. The reaction force Fz(t) was analyzed on an on-line system by using our own software which derived the velocity-time and distance-time functions from the Fz(t) curve and computed 23 biornechanical variables describing the structure of the vertical jump from the point of view of time, force, impulse, velocity, and the track of the center of gravity. Data were elaborated by statistical procedures based on STATGRAPHICS package (basic statistical characteristics, t-test, correlation analysis). Statistical characteristics of measured variables have provided the information about the inter-individual variability of the time, force, track, and velocity structure of the movement in the vertical jump for both men and women. This information was the basis for the next step of our research. Reproducibility of the structure of the vertical jump varies for different groups of variables (rtt = 0.50 - 0.98). The highest stability was found in the strength parameters (take-off force, braking and accelerating impulse, rtt = 0.91-0.98) and the lowest level of stability for the time structure of the movement (at = 0.45-0.66). Statistical analysis has confmed a significant difference in the structure of the vertical jump between the group of men and women

EVALUATION OF MECHANICAL POWER OUTPUT MEASUREMENT IN A BENCH PRESS EXERCISE UNDER VARIABLE LOAD

The study is aimed to investigate evaluation of mechanical power output measurement during bench press exercise by methods which are used at training practice. As the criterion of power output measurement evaluation we selected a method which estimates the output by means of empirical 3D mechanical model (work in progress)