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Application for Communication with the Lost Mobile Phone
Sládek, Petr ; Rychlý, Marek (referee) ; Očenášek, Pavel (advisor)
This thesis is dedicated to communication with lost mobile device throw the Internet with its owner because of the possibility of finding, return or lock the device. It focused on analysis existing solution and draft own mobile application for Android platform with supportive web application, This thesis also summary basic principles of creating application for Android OS and communication with cloud base service Google Cloud Messaging.
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Low level measurement
Roubal, Zdeněk ; Lazar, Josef (referee) ; Sládek, Petr (referee) ; Steinbauer, Miloslav (advisor)
The doctoral thesis presents methods for low-level measurements, which are exemplified by the general measurement of air ion concentration. Within the first section, the author progressively identifies certain critical effects influencing the concentration of air ions, and these effects are to be considered in evaluating the uncertainty of the measured concentrations. Thus, the thesis aims to provide a systematic description of the procedures and requirements related to low-level measurements; the proposed description then involves a discussion of the process reliability requirements, namely the factors of repeatability, elimination of errors, and definition and describability of measurement uncertainties. Such methodology facilitates, among other activities, the long-term monitoring of air ion concentration in extreme environments, including caves or spaces characterized by high temperatures and humidity. The use of common methods for determining the air ion mobility spectrum is accompanied by a number of disturbing effects, such as spurious fluctuation in the concentration of air ions in time. The experimental section of the thesis describes the testing of different configurations of the measuring device (a collecting electrode and a polarization capacitor); at this stage, we seek the most advantageous distribution of the electrostatic field in the sensor – a Gerdien tube. The systematic suppression of the influence of spurious fluctuations in air ion concentration during the measurement of saturation characteristics is carried out with the least-squares numerical method (as a supporting element), a hybrid technique to describe and evaluate the experimental model. In the second part of the thesis, the methodology of low-level measurement is complemented with procedures for the measurement of freezing potential. This latter domain, as an overall experimental approach applicable during phase changes of the sample, has hitherto not been sufficiently characterized from the metrological perspective, in an up-to-date manner; several subregions of the said domain remain somewhat obscured and deserve significantly more attention. In the given context, this thesis systematically considers a problem where comparable measurement results produced by multiple authors are not available. The measuring methodology proposed herein was utilized in applied research to facilitate the fabrication of an apparatus for the experimental measurement of freezing potential in pre-defined samples; the obtained results then lead us to conclusions with respect to the evaluation of effects that cause differences in the measured data, and the results can be further compared with those obtained by other researchers investigating the given segment of the problem.
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The Analysis and Optimization of Selective Technological Processes for Contacts on Crystalline Silicon Solar Cells
Hladík, Jiří ; Sládek, Petr (referee) ; Myslík, Vladimír (referee) ; Szendiuch, Ivan (advisor)
The submitted work deals with the methods for manufacturing and analysis of contacts on crystalline silicon solar cells. It is focused on selective processes for the production of solar cells metal contacts. The masking feature of silicon nitride is used for selective silicon etching, selective phosphorus diffusion and selective electro-less nickel deposition. Properties of metal contacts precursors are investigated using optical microscopy and their electrical properties using methods based on a four-point probe method. Results are used for the manufacturing of silicon, solar cell with an innovative type of the structure of the front side metallization: chemical nickel, conductive adhesive and copper wire. This approach allows to reduce shading of the front area of PV cells with the ability to avoid usage of busbars. The another advantage of this approach is in replacement of costly silver in at least 2/3 cross section of the front side metallization. Selective ablation of silicon nitride layer was conducted by means of IR laser beam.
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Anyalyze of photovoltaic cell by noise diagnostic
Husák, Marek ; Sládek, Petr (referee) ; Vaněk, Jiří (advisor)
The master’s thesis deals with the noise diagnostic in the solar cells. Describes the main kinds of noises. The samples were quality and reliability screened using noise reliability indicators. The samples were surveyed by measuring the I-V characteristics, the noise spectral density as a function of forward voltage and frequency. It was calculated the noise spectral density as a function of forward current.
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Study of influence degradation to fotovoltaic cells properties
Tulková, Tereza ; Sládek, Petr (referee) ; Zmeškal, Oldřich (advisor)
The thesis examines degradation of photovoltaic cells and modules. Degradation assessment was based on the data gathered from the photovoltaic system installed at the Pedagogical Faculty of Masaryk University in Brno, Poříčí 31. The research focuses on influence of external factors on the amount of power supplied to the grid by the system. Theoretical part of the thesis summarizes state-of-the-art knowledge about photovoltaic conversion and devices taking the advantage of the principle. The first part of the thesis describes production and application of photovoltaic cells and their impact on the environment. Second part of the thesis deals with the principle of photovoltaic conversion. Next part lists materials used for the production of photovoltaic cells and the process of encapsulation. The fourth part summarizes knowledge about degradation of photovoltaic panels. Experimental part of the thesis statistically analysis the data gathered from the above mentioned power plant. Influence of degradation factors (surface temperature of PV panel, air temperature, wind velocity and radiation intensity) on effectiveness of energy conversion was examined in particular. The published results can be applied on analysis of new projects and/or used for modification of production technological processes.
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Stanovení závislosti jeskynního mikroklimatu na vnějších klimatických podmínkách ve zpřístupněných jeskyních ČR
Český hydrometeorologický ústav, pobočka Brno ; Správa jeskyní České republiky, Průhonice ; Lejska, Stanislav ; Hora, Petr ; Kohut, Mojmír ; Rožnovský, Jaroslav ; Piasecki jacek, Wladyslaw ; Sládek, Petr ; Zajíček, Petr ; Hebelka, Jiří ; Drbal, Karel
V rámci dvou dílčích úkolů DÚ 1 Vyhodnocení mikroklimatu jeskyní a vazby na vnější prostředí a DÚ 2 Vytvoření a ověření funkčnosti jednotného kontinuálního sledování mikroklimatických poměrů jeskyní proběhla měření v Kateřinské, Amatérské a Punkevní jeskyni a ve Slopsko-šošůvských jeskyních. Byly popsány klimatické poměry Moravského krasu a vyhodnoceny změny mikroklimatu jeskyní v závislosti na návštěvnosti. je popsána údržba a kalibrace měřicích systémů
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Stanovení závislosti jeskynního mikroklimatu na vnějších klimatických podmínkách ve zpřístupněných jeskyních ČR
Český hydrometeorologický ústav, pobočka Brno ; Správa jeskyní České republiky, Průhonice ; Lejska, Stanislav ; Zahradníček, Pavel ; Kohut, Mojmír ; Rožnovský, Jaroslav ; Jacek, Wladyslaw ; Sládek, Petr ; Zajíček, Petr ; Hebelka, Jiří ; Drbal, Karel
Jsou popsány mikroklimatické poměry sledovaných jeskyní a mezoklimatické poměry oblasti. Jsou uvedeny výsledky měření mikroklimatu Punkevních, Sloupsko-šošůvských jeskyních, Amatérské a Kateřinské jeskyně. Je zhodnocen vliv návštěvnosti na změnu mikroklimatu a vazba na vnější prostředí. V závěru je diskutován současný stav možné scénáře vývoje.
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Stanovení závislosti jeskynního mikroklimatu na vnějších klimatických podmínkách ve zpřístupněných jeskyních ČR
Český hydrometeorologický ústav, pobočka Brno ; Správa jeskyní České republiky, Průhonice ; Lejska, Stanislav ; Hora, Petr ; Kohut, Mojmír ; Rožnovský, Jaroslav ; Piasecki jacek, Wladyslaw ; Sládek, Petr ; Zajíček, Petr ; Hebelka, Jiří ; Drbal, Karel
Zákonitosti pohybu a změn ovzduší a jejich vliv na krasové procesy jsou předmětem studia krasové klimatologie. Monitorování jednotlivých parametrů kryptoklimatu je snaha sladit množství návštěvníků v jednotlivých skupinách a frekvenci vstupů tak, aby nedocházelo k výraznějšímu ovlivnění tohoto kryptoklimatu a narušení ekologické stability jeskynního systému. kromě návštěvníků ovlivňuje hodnoty i okolní prostředí. Naměřené hodnoty klimatických prvků z různých míst krasového území lze kromě poznání vzájemných vazeb mezi vnitřním a vnějším prostředím využít i k bližšímu poznání mezoklimatických podmínek jednotlivých biotopů typických pro krasový reliéf.
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Future of disk arrays in SSD era
Sládek, Petr ; Koubský, Petr (advisor) ; Vojta, Tomáš (referee)
The thesis aims at verification of using emerging Solid-State drives in disk arrays. The advent of SSD disks caused a small revolution in area of data storage, because the growth performance of hard drives has been slow compared to other PC components. But an entirely different principle of operation could mean compatibility problems between SSD and related technologies, such as RAID. This thesis aims at analyzing all the relevant technologies, mainly HDD, SSD and RAID. To achieve this objective, information from literature, articles and other appropriate sources will be used. Other objectives of this thesis are to determine how much are the SSDs suitable for use in the disk array, because low performance RAID controllers or different principles of operation could limit their efficiency. This question should be answered by submission of selected types of storage arrays to synthetic and practical tests of performance. The final goal is to use financial analysis of the test solutions as a shared file storage. Today, remote access to data is used by a wide range of job positions. Slow storage could mean inefficient use of working time and therefore unnecessary financial costs. The goal of my work is primarily to provide answers to the questions mentioned above. Currently it is very hard to find tests of more complex forms of disk arrays based on solid-state drives. This article can be also very useful for companies where fileservers are used to share user data. Based on the result of cost analysis, the company can then decide what type of storage is best for its purpose.
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Disk arrays, use in small business
Sládek, Petr ; Jandoš, Jaroslav (advisor) ; Čech, Milan (referee)
Thesis aims to examine issues of disk arrays and their deployment in small business. It will focus not only on theoretical description of technologies, but also to carry out practical tests and performance characteristics, conduct or analysis in the field of non-standard situations. To describe the theoretical background of the problem, I used the available literature and web resources. The practical test then served on borrowed Adaptec RAID controller and on the motherboard Asus. Given the rapid evolution of SSD drives in my test also included the performance tests of this device. Recent work also includes a survey among small business company, which serves to assess the various criteria for evaluation. Currently, it is very difficult to find specific tests of controllers or less usual levels of disk arrays, which many manufacturers use. The results can therefore serve as a valuable source of information for users seeking the best solution for their needs. They may be useful as theoretical tests and service experience. From the previous lines then follows the structure of work. The first part is purely theoretical, and aims to acquaint the reader with problems. The second part focuses on the synthetic and practical test of arrays and SSD and is accompanied by a description of the behavior of various configurations of hard disk failure. The last two parts evaluates the results, the criteria are partially dependent on the results of the survey, which can be found in the last part.
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