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Effective Optical Function in Fibre Photonics Networks
Havliš, Ondřej ; Vlček, Čestmír (referee) ; Dostál, Otto (referee) ; Slavíček, Karel (advisor)
This dissertation focuses on efficient optical functions in fiber photonic networks, testbeds and multiband polygon. These functions include optical amplification, switching, routing and filtering of the optical spectrum. The theoretical part of the thesis deals with optical amplification, where different types of optical amplifiers are described. These employ various principles for their function, such as the use of Raman scattering, rare earth doped fibers – primarily Erbium, and lastly semiconductor structures. The practical part of the work is focused on the use and verification of efficient optical functions and their services, i.e. transmission of classical telecommunication data and transmission of ultra-stable quantities (transmission of accurate time and ultra-stable frequency) in fiber photonic network, testbeds and multiband polygon.
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Effects of assembling on quality of cable systems
Konvalinka, Vladimír ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This master´s thesis deals with questions of measuring of cabling systems. There is described the evolution of structured cabling including the rules of their installation, approval and their final measurement. The first part of this work is dedicated to the conception of structured cabling and its history which originated at the beginning of 80s when the first personal computers began to appear at the market. The necessity of mutual communication of their users caused forceful development of networks and technologies. As a result lots of single-purpose, incompatible and mutual independent cabled distributions were developed. This method of cabling was uneconomical, very demanding on service and impractical for network expansion. That’s why the universal cabled system was developed whose baseline became a twisted pair. Characteristics of structured cablings are designed in order it could be possible to transmit whole rang of applications through them. Metallic cables and nowadays also optical cables are used for their installation. The cabling system consists of lots of other items among them we can rank items active and stable. It’s necessary to scale lots of criteria which involve the quality of data transmission in this network. The measurement is done by the devices which comply with basic requirements determined by the standards according to technology. There are described the rules and proper processes of installing cabling systems, which should be followed while installations. At the end of my thesis there are mentioned the results of the measurements on simulation segments of cabling system which serve as completion certificates between an installation company and a consumer.
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Legal Aspects of Fighting Cybercrime
Dostál, Otto ; Vlček,, Martin (referee) ; Šárek, Milan (referee) ; Hajný, Jan (advisor)
The thesis deals with the topic of computer crime. Foremost, it demonstrates on an example of the operation of a medical image information processing system some selected aspects of this issue. It shows that it is always necessary to monitor the current state of the technical knowledge at the time, but also the need of addressing the issue within the corresponding legal limits. The thesis presents criminal law reality as a complex system. The links between different parts of the system are examined, and possible shortcomings are considered. The legal instruments and legal limits of the procedures that can be used against cybercrime are evaluated. The thesis focuses especially on the issue of obtaining evidence under the Czech Criminal Procedure Code. It presents a proposal on how to understand individual procedural legal institutes and for what purposes and how to use them. Consequently it suggests legal procedures for specific selected practical situations.
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Application of GPRS module for real-time transmission of JPG files
Rusinský, Jan ; Hošek, Jiří (referee) ; Dostál, Otto (advisor)
This document describes a design procedure of interface between VGA camera and GSM/GPRS modem for displaying JPEG pictures captured by camera on website. Interface is realized by eight-bit micricontroller ATMEL with application written in C language. For picture transfer to server a TCP/IP stack is implemented into modem. The document is divided into two main parts. The first part describes architecture of the system, used components (camera, modem, microcontroller) and electronic circuit design. The second part of the document is focused on the software for the system. Firstly operating system of modem is desribed, OpenAT development environment for modem application design and WIPsoft library, which is used to implement TCP/IP stack. Next is described application for microcontroller which controlls camera and modem. Last part of this document describes server application and web interface.
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Optical Convertors
Chleboun, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
Optical converters are used in various types of optical networks to provide end-users of data and voice services and also allow reception of television broadcasting, which is transmitted through optical media. The current trend is the construction of FTTH networks (Fiber To The Home), which, thanks to optical fibre, have reduced the speed or capacity, as in the case with metallic networks. The proposal is the need to consider positive and negative factors associated with building of concrete network with a specified number of users and location. Each network consists of passive and active components. Passive can be used for transmission of information, therefore they are mainly elements transmission medium. Active part includes elements for sending and receiving information transmitted by optical media. Transmitters vary their technical implementation, quality and reliability. This obviously affects the price of both active and passive parts. The cost of the operation of the network are also increased with demands of control. The advantage is the efficient management, which is guaranteed by return of the cost to build a FTTH network. Optical network with a system of remote management converters is a new trend of optical communications.
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PMD - polarization mode dispersion and its effects on data transport
Trávníček, Pavel ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
My graduation thesis is concerned with the effect of polarization mode dispersion on transmitted signal by optical line. It describes external and internal causes of origination of polarization mode dispersion. On the basis of these effects there is a differential group delay (DGD). It is the time delay in meantime within individual modes. DGD results in a time extension of impulsion and limitation of maximum bit rate. This thesis contains localization methods of part of gossamer filament with increased value of PMD by POTDR method. This method is based on the principium of back dispersion and its modifications SOP a DOP. Very important chapter of this thesis is the measurement of the polarization mode dispersion. There are described methods of PMD measurement. It is the interferometric and polarimetric method and the method of state of polarization. The major part of this thesis is about the reduction of polarization mode dispersion effect. This part is divided into two parts. First part is about the methods of PMD effect reduction and the second one is about the PMD compensation. The discrepancy between these two parts is the reduction way of PMD effect on transmitted channel. The compensation use the compensation components inserted into the transmission path. By PMD reduction methods we can solve the problems from the view of changing of fibre or all cable. For better understanding of polarization mode dispersion effect there are simulated 4 optical lanes of various parameters. The simulation output is the eye diagram which provides the view at results of transmission lane. In the final part there is the evaluation of measured parameters of optical lanes simulated in a laboratory.
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Analysis of Speech Signals for the Purpose of Neurological Disorders IT Diagnosis
Mekyska, Jiří ; Dostál, Otto (referee) ; Přibilová, Anna (referee) ; Smékal, Zdeněk (advisor)
This work deals with a design of hypokinetic dysarthria analysis system. Hypokinetic dysarthria is a speech motor dysfunction that is present in approx. 90 % of patients with Parkinson’s disease. The work is mainly focused on parameterization techniques that can be used to diagnose or monitor this disease as well as estimate its progress. Next, features that significantly correlate with subjective tests are found. These features can be used to estimate scores of different scales like Unified Parkinson’s Disease Rating Scale (UPDRS) or Mini–Mental State Examination (MMSE). A protocol of dysarthric speech acquisition is introduced in this work too. In combination with acoustic analysis it can be used to estimate a grade of hypokinetic dysarthria in fields of faciokinesis, phonorespiration and phonetics (correlation with 3F test). Regarding the parameterization, features based on modulation spectrum, inferior colliculus coefficients, bicepstrum, approximate and sample entropy, empirical mode decomposition and singular points are originally introduced in this work. All the designed techniques are integrated into the system concept in way that it can be implemented in a hospital and used for a research on Parkinson’s disease or its evaluation.
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Authentication Using Lightweight Cryptography
Člupek, Vlastimil ; Uchytil, Stanislav (referee) ; Dostál, Otto (referee) ; Zeman, Václav (advisor)
The dissertation thesis deals with cryptographic protocols for secure authentication of communicating parties, which are intended primarily for low-cost devices used in Internet of Things. Low-cost devices represent computationally, memory and power constrained devices. The thesis focuses mainly on the possibilities of using mathematically undemanding cryptographic resorces for ensuring integrity of transmitted dat, authenticity of and secured transmission of data on low-cost devices. The main goals of the thesis focus on the design of new advanced cryptographic protocols for ensuring integrity of transmitted data, authenticity, confidentiality of transmitted data between low-cost devices and authenticity with non-repudiation of done events. The thesis describes proposal of three authentication protocols, one unilateral authentication protocol and two mutual authentication protocols. The thesis also describes proposals of two protocols for secured transmission of data between two devices, one protocol without a proof of receipt data and one protocol with proof of receipt data. In this thesis is also performed a security analysis and a discussion to proposed protocols.
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Automatic detector of vehicle road accicents
Žurek, Jan ; Morský, Ondřej (referee) ; Dostál, Otto (advisor)
This master‘s thesis treat of car safety. It includes an introduction into already existing active and passive safety systems and briefly describes their basic principles. It also includes a description of basic principles of car electronic systems. It will acquaint us also with elementary calculations in the area of car crashing into a solid obstacle. On base of this information was developed and consequently realized development module of an automatic car accident alarm that transfers information using SMS messages to a cell phone. The message contains date, time and GPS coordinates of the accident and acceleration sensor readings in three axes.
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Challenges in Optimal Bandwidth for Medical Image Transfer
Schindler, Vladimír ; Šimák, Boris (referee) ; Šárek, Milan (referee) ; Dostál, Otto (advisor)
This dissertation thesis is focused on the optimization of bandwidth parameters for the transport of medical image data between medical devices and remote data storage. As real and fully functional structure, which will be analyzed in this work. It was selected system MeDiMed (Metropolitan Digital Imaging System in Medicine). The thesis examines the operation of the small health organizations and their modalities, which use this system for remote data archiving. Traffic analysis is then statistically processed. The thesis also deals with the analysis of increasing the security during accessing health system, and assesses its impact on transmitted data. The effect of setting the transmission parameters and the most widely used types of ciphers on the transfer speed is also compared.
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