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Polymer optical fibers - POF
Mitrič, Martin ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
Polymer Optical Fibers - POF in recent years reach into values attenuation about 10 dB • km-1. This is the value that makes these fibers applicable for data transmissions over short distances. Between the great advantages of these fibers include simple installation and easy preparation of the connectors. The aim of of this work is to introduce the issue of the POF fiber. The work begins with becoming familiar with different types of fiber POF, their basic characteristics and differences. It also deals with methods of linking these different types of fibers and connectors designed for these fibers. Another chapter focuses on the possible use of these fibers in FTTx networks and their future. Work continues overview of the types of optical access network and transmission design polygon using POF fibers for laboratory purposes. The final part presents the results of measurements of fundamental properties of the POF fiber.
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Advanced Security Methods of Medical Image
Roček, Aleš ; Šimák, Boris (referee) ; Molnár, Karol (referee) ; Dostál, Otto (advisor)
Medical institutions adapt digital based archiving of patients records images to fulfil its advantages like availability, easy sharing, high resolution etc. Digital form of records brings apart from advantages also disadvantages at security risks. It is easier attacking, stealing, using without authorization etc. This thesiss deals with this security issues, describes the needs and approaches to security, explains the reasons for deployment of watermarking. It names three main methods of medical image watermarking and compares their plus and cons: zero, reversible and watermarking in Region Of Non Interest (RONI). New method of Zero-reversible-RONI watermarking, that combine advantages of described methods, is proposed. For practical tests of properities of proposed method was used huge database of medical images. Application of the proposed method on this database delivers very promising results. Practical results discussion and comparison with other medical imaging watermarkikng methods are at the end of this thesis.
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Cableless optical transmission
Němec, David ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This diploma thesis first handles the general issues concerning free space optics in the atmosphere, which will then discuss the components and adjustments modification RONJA in laboratory. The aim is to simplify the control of laboratory FSO with programming compensation for HyperTerminal and provide external simulation influences on the FSO measurements in non-standard situations such as fog. It was created RONJA terminal with just cursor control to communicate with the serial port, ping, and FTP protocol. In the last part of this work were measured by an abnormal situation on the optical link RONJA.
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The Segmentation of Ultrasound Images for Artery Wall Detection and Intima-Media Thickness Measurement
Beneš, Radek ; Chromý,, Erik (referee) ; Dostál, Otto (referee) ; Říha, Kamil (advisor)
The thesis focuses on the measurement of intima media thickness, which seems to be a significant marker of the risk of cardiovascular events. Intima media thickness is measured in ultrasound image displaying the common carotid artery in its longitudinal section. In the longitudinal section the intima and media layers are visible. Thesis is discussing both technical and medical background and summarizes state of the art in this field. The main part of the thesis describes the novel automatic system for measurement of intima media thickness. Proposed system includes also robust method for artery localization and therefore is able to process raw B-mode data from ultrasound station without any initialization or manual preprocessing.
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Polarization mode dispersion - PMD
Ťupa, Martin ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
Polarization mode dispersion PMD becomes the most limiting factors for achieving high-speed optical transmission. The size of the dierencial group delay between the polarization plane is influenced by many different factors and therefore accurate measurement of PMD should be done in all phases of building and operating optical path.
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Measurement of the optical fiber
Procházka, Jakub ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This bachelor's thesis deals with measurement methods of optical fiber. In the thesis, methods for measurements of attenuation, chromatical dispersion, and polarization mode dispersion are discussed. The thesis also deals with methods for measurement of attenuation of passive components and their reflections loss. Also discussed are parameters of selected types of optical fibers, basic findings about optical transmission and principle of wave multiplexing. The practical portion of the thesis deals with measurement of a new optical polygon in the Academic Optical Network in Brno.
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Optical fibres and their polarization effect
Klesnil, Ondřej ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This project describes the fundamental concepts and basic theory of polarization mode dispersion (PMD) in optical fibers. There are described basic the relation between Jones vectors and Stokes vectors, rotation matrices, the definition and representation of PMD vectors, the laws of infinitesimal rotation. After the introduction the first conception with bases of polarization mode dispersion (PMD) in optical fibers, they have become an important body of knowledge basic for the design of high-capacity optical communication systems. PMD effects are linear electromagnetic propagation phenomena occurring in so-called “single-mode“fibers. Despite their name, these fibers support two modes of propagation distinguished by their polarization. Because of optical birefringence in the fiber, the two modes travel with different group velocities, and the random change of this birefringence along the fiber length results in random coupling between the modes. With current practical transmission technology the resulting PMD phenomena lead to pulse distortion and system impairments that limit the transmission capacity of the fiber. I describe different ways of measuring PMD in optical fibre, PMD compensation techniques and analyse PMD results in optical fibres.
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NG - PON technologies
Balon, Radek ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The main object of the master thesis was to familiarize with optical networks, describe the latest current technology of passive optical networks and create a simple simulation of our chosen technology. This thesis was divided into several parts. The first part deals with passive network architecture. I illustrated the basic functional elements which are present in optical networks. I described the active elements and principles of data transmission in the distribution network. To conclude this chapter I described the different standards that are defined for the passive network. In second part I familiarized myself with key parameters and their adverse effect on the transmitted signal. Another part deals with the new technologies that are defined for the next generation of passive network NG-PON. I described the principles of data transmission in these networks and their advantages and disadvantages. The last part deals with creating custom simulations of technology defined by standard NG-PON using OptSim 05.02 Subsequently I have collated all the results of the various technologies and show the advantages and disadvantages of each.
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Search storage of fiber optic cables
Čučka, Milan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This work deals with the possibilities of laying and reverse lookup optical routes with the help of modern technology. Hereinafter, there are possibilities for documentation and registration of fiber optic lines. Speaking of thesis, it focuses on optical technology, advantages and disadvantages of this technology. Introduction focuses on fiber optic cable and related theoretical knowledge. Additionally, there are introduced comparisons with metallic lines. Another part is based on different searching methods for optical cables using metallic elements are analyzed in a detail. This section discusses galvanic and inductive methods. Subsequently, the thesis deals with searching for optical paths with the help of EMS (electronic marker system). Moreover, there are described individual types of electronic tags which are used in the installation of different kinds of lines. There are also briefly described seeker EMS markers, made by Dynatel. In addition to my work you can find the description of GPS (Global Positioning System) technology and routing the cable with the help of GPS system. Finally, possibility of documentation and evidence in the ArcGIS from ERSI and in the SPIDER-fiber from Gisoft is given. The overall functions of individual programs and their options are analyzed. The last section presents the implementation of laboratory tasks and programming burial markers, creating navigation in Urwigo and realisation with Openwing in Nokia phone. In the end of the work is map with markers positions.
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