The subject of this thesis is open source software and free software in term of utilization for business. The goal is to provide conditions and areas suitable for using of open source software and free software. The theoretical part gives basic terms, a list of organizations active in this area, classification of free software and a comparison of particular free software licenses. The practical part includes results of two inquiries of free software using: 1) personally made inquiry in Czech firms, 2) Internet inquiry of users. Further, a search of available free programmes has been made -- in term of utilization. The main benefit of the work is an evaluation of business opportunities for free software in particular utilization areas and determination of business models suitable for them. In the framework of this work, the author made an Internet portal on free software - to make the results of the work and external sources available to the public.

This thesis covers the topic of copyright law in schools. It is an overview of the usage of the copyright law, especially in the practice of pupils, students, teachers and other pedagogical workers. It tries to present an integrated overview of basic rules which can be used in the educational process in the areas of creation of an original work, licenses, non-contractual usage of the original works and the liabilities for breaching the copyright law. It covers the situations when the pupils, students, teachers and other pedagogical workers are the creators of an original work as well as cases when these people want to use original works created by others. A part of this thesis are comments from practice and findings based on surveys and discussions with the pupils and pedagogical staff.

Memoria (licenciado en ciencias jurídicas y sociales) / No autorizada por el autor para ser publicada a texto completo / Así, el objetivo principal de la presente investigación es realizar un estudio respecto a las razones que esgrime la Free Software Foundation (FSF) al momento de considerar una licencia libre como incompatible con la GNU GPL. En conjunto con lo anterior son objetivos especifico de la presente investigación: presentar los aspectos relevantes de cada licencia, principalmente los derechos que concede y las condiciones que impone a los usuarios del software licenciado y exponer las razones esgrimidas por la FSF para considerar la licencia como incompatible, presentado una 8 opinión acerca de dichas razones y exponiendo otros elementos de incompatibilidad no considerados por la FSF en su análisis, si es que existen. Para lograr los anteriores objetivos, será necesario comenzar con un capítulo dedicado a la propiedad intelectual, en general, centrándonos particularmente en la rama del derecho de autor: su concepto, el objeto de su protección, los titulares de dicho derecho, el contenido de éste y cuál es su duración

The work deals with the use of software-defined radio as a probe for monitoring the operation of wireless communication according to the IEEE 802.11a/g standard. In the theoretical introduction, the concept of software-defined radio as a hardware device with software programmable circuits enabling the transmission or reception of signals in theoretically any frequency band is introduced. The introduction also contains adescription of selected devices and the IEEE 802.11 protocol with its most used additionsand modulations. In the first part of the practical part of the work, wireless communication is capturedusing a wireless network card in monitoring mode. The intercepted communication was decrypted and this decrypted traffic was compared with the data captured by the probe within the network. These results then served as acomparative basis for software-defined radio capturing. The focus of this work is to verify the capabilities of software-defined radio and its use for sniffing wireless communicationin the frequency band 2.4 GHz and 5 GHz. The attempt to use a software-defined radio here results from the scalability and adaptability that a wireless card cannot offer due to fixed hardware parameters. LimeSDR mini, LimeSDR and bladeRF 2.0 devices were used for capture. First, the configuration of the operating system, the installation of drivers and programs for control and work with selected devices are described. After verifying the functionality of the software-defined radio, a model of a signal decoder with the parameters of the IEEE 802.11g standard captured from the radio spectrum was put into operation. Finally, the data streams captured by the software-defined radio and the wireless network card were compared side by side. The results showed that the software-defined radio in the used configuration captures only a part of the total volume of transmitted frames.

Während sich der Chemnitzer Linux-Tag über die vergangenen fünf Jahre mit jedem Mal in der Zahl der Aussteller, Helfer und Gäste steigerte, wuchs auch in jedem Jahr das Tagungsnetzwerk. Den Informatikern wird häufig nachgesagt, daß sie wenig dokumentieren würden. Dieses Vorurteil traf auch für das Netzwerk der vergangenen Chemnitzer Linux-Tage zu. Unter anderem, um diesem Mißstand abzuhelfen, haben wir uns bemüht, möglichst detailliert Informationen über Konzept, eingesetzte Technologieen und konkrete Konfiguration des Tagungsnetzwerks des Chemnitzer Linux-Tags 2004 zusammenzutragen.

In wireless communication systems, one of the most important resources being focused on all the researchers is spectrum. A cognitive radio (CR) system is one of the efficient ways to access the radio spectrum opportunistically, and efficiently use the available underutilized licensed spectrum. Spectrum utilization can be significantly enhanced by developing more applications with adopting CR technology. CR systems are implemented using a radio technology called software-defined radios (SDR). SDR provides a flexible and cost-effective solution to fulfil the requirements of end users. We can see a lot of innovations in Internet of Things (IoT) and increasing number of smart devices. Hence, a CR system application involving an IoT device is studied in this thesis. Opportunistic spectrum access involves two tasks of CR system: spectrum sensing and dynamic spectrum access. The functioning of the CR system is rest upon the spectrum sensing. There are different spectrum sensing techniques used to detect the spectrum holes and a few of them are discussed here in this thesis. The simplest and easiest to implement energy detection spectrum sensing technique is used here to implement the CR system. Dynamic spectrum access involves different models and strategies to access the spectrum. Amongst the available models, an interweave model is more challenging and is used in this thesis. Interweave model needs effective spectrum sensing before accessing the spectrum opportunistically. The system designed and simulated in this thesis is capable of transmitting an output from an IoT device using USRP and GNU radio through accessing the radio spectrum opportunistically.

The presented work concerns problems of more effective using hardware and also free software. The first part of my work presents generally free GNU/Linux distributions and this part is concentrated on two distributions. The first is Red Hat Enterprise Linux which is installed in the server of the hospital information system Clinicom. The second is live distribution Slax that is used for testing of terminal connection to the hospital information system Clinicom. The second part of my work is generally concentrated on the hospital information systems and there is presented the firm SMS solution at the end. It is the hospital information system Clinicom. The next part is generally concentrated on the workload server monitoring. It monitors both userlogins and allocated memory size. Then there are discused problems of solution of unthought-of events, for example blackout, and the one solution is described there. The last part is concentrated on implementation of the security connection to the hospital information system Clinicom and it presents live distribution Slax as distribution for thin client.

[pt] Nesta tese de doutorado foi investigado, por meio de simulações computacionais e em laboratório utilizando Matlab, GNU Radio e GNU Radio Companion (GRC), o desempenho de redes de Rádio Cognitivo com sensoriamento individual (SS) e com sensoriamento cooperativo (CSS) do espectro considerando o algoritmo não paramétrico de detecção de energia e diferentes abordagens deste método de detecção. Foi também implementado um cenário de medição em tempo real usando os equipamentos de rádio definido por software (SDR por suas siglas em inglês) conhecidos como Universal Software Radio Peripheral (USRP). Os cenários de medição consideram a cooperação, baseada na utilização de regras de fusão de dados do tipo hard, no sensoriamento local de sinais de TV Digital por usuários cognitivos não licenciados. A principal contribuição desta tese de doutorado baseia-se na formulação do método de energia combinando os conceitos da teoria clássica do sensoriamento de espectro das redes de Rádio Cognitivo, tanto com sensoriamento individual (SS) como sensoriamento cooperativo (CSS) de espectro, com um cenário de implementação em laboratório levando em conta os requisitos, parâmetros técnicos e de operação do equipamento de medição SDR. / [en] This PhD thesis investigate the performance of cognitive radio networks with single sensing (SS) and cooperative spectrum sensing (CSS) networks through computational and laboratory simulations using Matlab, GNU Radio and the GNU Radio Companion (GRC) computational radio software, considering the non-parametric energy detection method and different approaches to this method. The implementation also includes a real-time measurement testbed scenario using Software Defined Radio (SDR) equipment, known as Universal Software Radio Peripheral (USRP). The measurement scenarios consider the cooperative local sensing of the digital TV by non-licensed cognitive radio users, based on hard fusion rules. The main contribution of this doctoral thesis is based on the formulation of the energy detection method combining the concepts of the classical theory of the spectrum sensing of Cognitive Radio networks, with both individual sensing (SS) and cooperative spectrum sensing (CSS), in a laboratory implementation scenario according to the requirements, technical parameters and operation of the SDR measuring equipment.

Vakuumbrytare som utsätts för höga kortslutningsströmmar (kA) kan förstöras om den rörliga kontaktdelen i brytaren studsar tillbaka för långt efter att den har nått sitt ändläge. Detta p.g.a. att det sker en spänningskollaps mellan kontaktytorna så att en ny ljusbåge uppstår vilket bränner sönder kontaktytorna. En lämplig dämpningsmekanism för att försöka förhindra en återstuds av kontakten fordras. Hur detta kan utvärderas m.h.a. en matematisk modell som bygger på en differentialekvation framtagen ur krafterna som verkar på det mekaniska fjädersystemet, för att försöka uppskatta dämpningskoefficient behandlas i denna rapport. Resultatet visar att en oljedämpare med en slaglängd på max 8 mm är bäst lämpad som dämpare av det mekaniska systemet. Detta baseras på de slutsatser som dras av den matematiska modellen ihop med jämförelser av det verkliga rörelsebeteendet hos brytaren. / <p>Programvaran (skript för Matlab/GNU Octave) som utvecklades för detta projekt kan med fördel användas som bas av framtida studenter som eventuellt fortsätter att arbeta med samma ämne hos Hughes Power System AB. Framför allt gränssnittet för in- och utmatning kan återanvändas så att mer tid kan läggas på kärnfrågan. Detta förutsatt att läroverket ifråga godkänner ett sådant förfarande.</p>

There has recently been growing interest in using physical layer network coding techniques to facilitate information transfer in wireless relay networks. The physical layer network coding technique takes advantage of the additive nature of wireless signals by allowing two terminals to transmit simultaneously to the relay node. This technique has several performance benefits, such as improving utilization and throughput of wireless channels and reducing delay. In this thesis, we present an algorithm for joint decoding of two unsynchronized transmitters to a modulo-2 sum of their transmitted messages. We address the problems that arise when the boundaries of the signals do not align with each other and when their phases are not identical. Our approach uses a state-based Viterbi decoding scheme that takes into account the timing offsets between the interfering signals. As a future research plan, we plan to utilize software-defined radios (SDRs) as a testbed to show the practicality of our approach and to verify its performance. Our simulation studies show that the decoder performs well with the only degrading factor being the noise level in the channel.