Using Cell Phone As Wireless Mouse

Tato bakalářská práce se zabývá návrhem a implementací aplikace, která umožňuje použít mobilní zařízení s operačním systémem Google Android jako bezdrátový touchpad a klávesnici pro ovládání počítače s operačním systémem Linux. Aplikace funguje na standardní síťové architektuře klient-server. Mobilní zařízení se do počítačové sítě připojuje pomocí bezdrátového síťového rozhraní WiFi. Pro vývoj jednotlivých částí byly použity programovací jazyky Java a C++. Práce se dále zabývá testováním této aplikace a možnostmi jejího dalšího vývoje.This bachelor's thesis describes the design and implementation of an application that allows to use a mobile device running the Google Android operating system as a wireless touchpad and keyboard to control a computer running the Linux operating system. It works on the standard client-server network model. The mobile device connects to the computer network via a wireless WiFi network interface. For the development of the individual components were used Java and C++ programming languages. The thesis also deals with the testing of the application and possibilities for its further development.

Improve Support for RESTful Processing in JBossESB

Cílem této práce je umožnit JBoss ESB komunikovat se vzdálenými aplikacemi pomocí REST. JBoss ESB je platforma, která odděluje aplikační logiku od procesních funkcí a umožňuje komunikaci mezi aplikacemi s různým rozhraním pomocí zasílání zpráv. REST je architektura, která poskytuje obecné rozhraní pro komunikaci mezi počítačovými systémy v síti. Tato práce popisuje návrh a implementaci integrace REST do JBoss ESB. Integrace je rozdělená na dvě části. Vstupní část přijímá REST požadavky, propaguje jejich obsah do JBoss ESB a generuje odpovědi. Výstupní část čeká na zprávy z JBoss ESB, ze kterých vytvoří REST požadavky, zašle je adresátovi a přijme odpovědi. Při implementaci REST v JBoss ESB je kladen důraz na integraci s projektem RESTEasy. RESTEasy poskytuje framework, který ulehčuje vývoj aplikací podporujících REST komunikaci.The goal of this work is to allow JBoss ESB to communicate with remote applications using REST. JBoss ESB is a platform that separates application logic from the process functions and enables communication between applications with different interfaces by sending messages. REST is an architecture that provides universal interface for communication between computer systems in the network. This work describes integration of REST communication architecture with JBoss ESB platform. The integration is divided into two parts. The input part accepts REST requests, propagates their content to the JBoss ESB and generates a response. The output part waits for the messages from JBoss ESB from which it creates the REST requests, sends them to the recipients and receives responses. The implementation puts emphasis on integration with the RESTEasy project. RESTEasy provides a framework that facilitates development of applications that support REST communication.

Identification of changes in surface texture of the selected materials by the method of acoustic emission

Bakalářská práce se zabývá sledováním vlivu změny drsnosti povrchu vzájemně se pohybujících kovových těles na vybrané parametry signálu akustické emise (AE). Vyhodnoceny jsou záznamy hodnot z měření signálu AE při pohybu bronzového a litinového tělesa po povrchu stabilní ocelové tyče. Výsledky tvoří podklad pro další výzkum možnosti hodnocení stupně opotřebení povrchu pomocí metody AE. Měření bylo realizováno na přípravku určenému k měření AE za pomocí sytému Dakel Xedo.This Bachelor thesis deals with monitoring changes in surface roughness of moving metal objects rubbing each other on selected parameters of acoustic emissions. Parameters of the AE signal during the movement of bronze and cast iron bodies on the surface of a fixed steel rod were measured, recorded and analyzed. These results can serve for further research on assessment possibilites of the degree of wear of a surface using the AE method. Measuring was performed using a measuring product intended for AE and the Dakel sensors and measuring software.

The (h,k)(h,k)-Server Problem on Bounded Depth Trees

We study the $k$-server problem in the resource augmentation setting i.e., when the performance of the online algorithm with $k$ servers is compared to the offline optimal solution with $h \leq k$ servers. The problem is very poorly understood beyond uniform metrics. For this special case, the classic $k$-server algorithms are roughly $(1+1/\epsilon)$-competitive when $k=(1+\epsilon) h$, for any $\epsilon >0$. Surprisingly however, no $o(h)$-competitive algorithm is known even for HSTs of depth 2 and even when $k/h$ is arbitrarily large. We obtain several new results for the problem. First we show that the known $k$-server algorithms do not work even on very simple metrics. In particular, the Double Coverage algorithm has competitive ratio $\Omega(h)$ irrespective of the value of $k$, even for depth-2 HSTs. Similarly the Work Function Algorithm, that is believed to be optimal for all metric spaces when $k=h$, has competitive ratio $\Omega(h)$ on depth-3 HSTs even if $k=2h$. Our main result is a new algorithm that is $O(1)$-competitive for constant depth trees, whenever $k =(1+\epsilon )h$ for any $\epsilon > 0$. Finally, we give a general lower bound that any deterministic online algorithm has competitive ratio at least 2.4 even for depth-2 HSTs and when $k/h$ is arbitrarily large. This gives a surprising qualitative separation between uniform metrics and depth-2 HSTs for the $(h,k)$-server problem, and gives the strongest known lower bound for the problem on general metrics.Comment: Appeared in SODA 201

Control PC Application Using Mobile Phone over Bluetooth

Výsledkem mé práce je aplikace, pomocí které lze ovládat programy na PC. Aplikace obsahuje serverovou část, která běží na PC a klientskou část určenou primárně pro mobilní telefony. Aplikace pro svůj běh potřebuje dva skripty. První napsaný v Javascriptu, který definuje jak ovládat konkrétní program. Druhý skript definuje uživatelské rozhraní na klientovi.The result of my work is application, from which you can control computer's programs. Application has server part, which runs at PC and client part generally dedicated to mobile phone. Application needs two scripts. The first is written in JavaScript and defines, how to control specific program. The second defines user interface.

Elastic properties of isotropic discrete systems: Connections between geometric structure and Poisson's ratio

The use of discrete material representation in numerical models is advantageous due to the straightforward way it takes into account material heterogeneity and randomness, and the discrete and orientated nature of cracks. Unfortunately, it also restricts the macroscopic Poisson's ratio and therefore narrows its applicability. The paper studies the Poisson's ratio of a discrete model analytically. It derives theoretical limits for cases where the geometry of the model is completely arbitrary, but isotropic in the statistical sense. It is shown that the widest limits are obtained for models where normal directions of contacts between discrete units are parallel with the vectors connecting these units. Any deviation from parallelism causes the limits to shrink. A comparison of the derived equations to the results of the actual numerical model is presented. It shows relatively large deviations from the theory because the fundamental assumptions behind the theoretical derivations are largely violated in systems with complex geometry. The real shrinking of the Poisson's ratio limit is less severe compared to that which is theoretically derived

Lower bounds on geometric Ramsey functions

We continue a sequence of recent works studying Ramsey functions for semialgebraic predicates in $\mathbb{R}^d$. A $k$-ary semialgebraic predicate $\Phi(x_1,\ldots,x_k)$ on $\mathbb{R}^d$ is a Boolean combination of polynomial equations and inequalities in the $kd$ coordinates of $k$ points $x_1,\ldots,x_k\in\mathbb{R}^d$. A sequence $P=(p_1,\ldots,p_n)$ of points in $\mathbb{R}^d$ is called $\Phi$-homogeneous if either $\Phi(p_{i_1}, \ldots,p_{i_k})$ holds for all choices $1\le i_1 < \cdots < i_k\le n$, or it holds for no such choice. The Ramsey function $R_\Phi(n)$ is the smallest $N$ such that every point sequence of length $N$ contains a $\Phi$-homogeneous subsequence of length $n$. Conlon, Fox, Pach, Sudakov, and Suk constructed the first examples of semialgebraic predicates with the Ramsey function bounded from below by a tower function of arbitrary height: for every $k\ge 4$, they exhibit a $k$-ary $\Phi$ in dimension $2^{k-4}$ with $R_\Phi$ bounded below by a tower of height $k-1$. We reduce the dimension in their construction, obtaining a $k$-ary semialgebraic predicate $\Phi$ on $\mathbb{R}^{k-3}$ with $R_\Phi$ bounded below by a tower of height $k-1$. We also provide a natural geometric Ramsey-type theorem with a large Ramsey function. We call a point sequence $P$ in $\mathbb{R}^d$ order-type homogeneous if all $(d+1)$-tuples in $P$ have the same orientation. Every sufficiently long point sequence in general position in $\mathbb{R}^d$ contains an order-type homogeneous subsequence of length $n$, and the corresponding Ramsey function has recently been studied in several papers. Together with a recent work of B\'ar\'any, Matou\v{s}ek, and P\'or, our results imply a tower function of $\Omega(n)$ of height $d$ as a lower bound, matching an upper bound by Suk up to the constant in front of $n$.Comment: 12 page

Effect of rolling resistance in dem models with spherical bodies

The rolling resistance is an artificial moment arising on the contact of two discrete elements which mimics resistance of two grains of complex shape in contact rolling relatively to each other. The paper investigates the influence of rolling resistance on behaviour of an assembly of spherical discrete elements. Besides the resistance to rolling, the contacts between spherical particles obey the Hertzian law in normal straining and Coulomb model of friction in shear

Discrete model for concrete fracture: numerical study of dynamic response

The contribution presents simulations on concrete specimens. The discrete meso-scale particlemodel with random geometry based on Voronoi tessellation is used. The model was enhanced with dynamic solver based on implicit Newmark method. Model is tested on cantilever beam loaded by a force at the free end to verify the ability of the model to simulate the dynamic behavior of a simple linear elastic material. Results computed with different time discretization and model settings are compared. The behavior of the model in nonlinear regime is investigated on concrete specimens loaded at different displacement rates. The constitutive law used within this contribution is insensitive to strain rate

Homogenization of discrete mesoscale model of concrete for coupled mass transport and mechanics by asymptotic expansion

Mass transport phenomenon in concrete structures is strongly coupled with their mechanical behavior. The first coupling fabric is the Biot's theory according to which fluid pressure interacts with solid stress state and volumetric deformation rate of the solid induces changes in fluid pressure. Another coupling mechanism emerges with cracks which serve as channels for the fluid to flow through them and provide volume for fluid storage. Especially the second coupling mechanism presents a challenge for numerical modeling as it requires detailed knowledge about cracking process. Discrete mesoscale mechanical models coupled with mass transport offer simple and robust way to solve the problem. On the other hand, however, they are computationally demanding. In order to reduce this computational burden, the present paper applies the asymptotic expansion homogenization technique to the coupled problem to deliver (i) continuous and homogeneous description of the macroscopic problem which can be easily solved by the finite element method, (ii) discrete and heterogeneous mesoscale problem in the periodic setup attached to each integration point of the macroscale along with (iii) equations providing communication between these two scales. The transient terms appear at the macroscale only, as well as the Biot's coupling terms. The coupling through cracking is treated at the mesoscale by changing conductivity of the conduit elements according to the mechanical solution, otherwise the two mesoscale steady state problems are decoupled and can be therefore solved in a sequence. This paper presents verification studies showing performance of the homogenized solution.Comment: 29 pages, 9 figure