• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 163
  • 17
  • 2
  • Tagged with
  • 182
  • 155
  • 53
  • 51
  • 26
  • 25
  • 24
  • 22
  • 18
  • 15
  • 15
  • 15
  • 15
  • 14
  • 14
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Detekce objektu ve videosekvencích / Object Detection in Video Sequences

Šebela, Miroslav January 2010 (has links)
The thesis consists of three parts. Theoretical description of digital image processing, optical character recognition and design of system for car licence plate recognition (LPR) in image or video sequence. Theoretical part describes image representation, smoothing, methods used for blob segmentation and proposed are two methods for optical character recognition (OCR). Concern of practical part is to find solution and design procedure for LPR system included OCR. The design contain image pre-processing, blob segmentation, object detection based on its properties and OCR. Proposed solution use grayscale trasformation, histogram processing, thresholding, connected component,region recognition based on its patern and properties. Implemented is also optical recognition method of licence plate where acquired values are compared with database used to manage entry of vehicles into object.
92

Polarizační vidová disperze - PMD / Polarization mode dispersion - PMD

Ťupa, Martin January 2011 (has links)
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.
93

Fotonická krystalická vlákna / Photonic crystal fibers

Dočkal, Martin January 2011 (has links)
This graduation thesis deals with use of unconventional optical fiber with the intention of photonic crystal fiber. There are described types of photonic crystal fiber, their physical, optical and transfer characteristics. There is explained what are the photonic crystals, principle of their function and possible types of crystals. There are also detailed types of photonic fiber commonly used in the optical fiber branch. There is also explained photonic crystal fiber its structure a hierarchy of its types. In this thesis are described and demonstrated different kinds of photonic optical fiber and their use. There is demonstrated principle of one-dimensional periodical structure of Bragg fiber using simulation software. There can be seen graphical comparison of the simulated optical fiber core to commonly obtainable fiber. Outcome of this graduation thesis should be explanation of function of photonic crystal fiber and possibility of finding new type of fiber with optimal dispersion characteristics for use in fiber optics.
94

Metody stabilizace frekvence polovodičových laserů / Methods of frequency stabilization of semicondutor lasers

Kozelský, Adam January 2011 (has links)
The main aim of the thesis is a frequency stabilization of the DFB semiconductor laser diodes. The temperature stability of the laser diode chip, the stability and the noise of the injection current and the backward reflections are the crucial parameters which affects the frequency stability. These influences are described and the resolution is proposed. The theory of the external methods of the frequency stabilization and the comparison of these methods is presented. One method was choosed and this method was realized for 760 and 1540 nm wavelength laser diodes. In this method was used the frequency stabilization based on the linear absorption to the spectral lines of the gases. The diploma work is closed by the measured results of the frequency stability of the used laser diodes and by the comparison of level of stability achieved by the other methods.
95

Neinvazivní měření glukózy v krvi / Non-invasive Blood Glucose Measuring

Vítová, Hana January 2012 (has links)
Goal of my master´s thesis is examination of non-invasive blood glucose measurement methods, and designing of device for non-invasive blood glucose reading. The introductory chapter of thesis contains description of know different methods for blood glucose measurement, mainly Near Infra-Red region (NIR) measurement with spectroscopy methods. This project describes pathology of Diabetes Mellitus, specifies how it is divided, and looks also on human metabolism. The theoretical part contains exploration of blood glucose measurement methods. Thesis continues with system scheme design for non/invasive glucose measurement device, based on present knowledge. Major principle of device is measuring with Infra-Red laser, bifurcate optic fiber and photodiode. Design of printed circuit board is also present. Document contains also designs of software diagrams for calibration and processing program written in C# language. Communication between device and computer is made via USB. Microcontroller with C language program is part of designed device. It is used to send measured values into PC and also receives data from computer. This data determines blood glucose concentration and their thresholds.
96

Využití optického vlákna jako senzoru pro lokalizaci mechanického chvění / Optical fibre utilization for localization of mechanical vibrations

Parduba, Jiří January 2013 (has links)
The thesis is focused on physical principles of signal transmission by optical fiber and effects that may have influence on such transmission. This knowledge is acquired with regard to future usage of optical fiber as a sensor for detection and localization of mechanical vibration. In the thesis, mentioned knowledge is taken in account and also there are described methods, which allow mechanical vibration for dozens of km. At the conclusion the laboratory sollution is suggested, allowing detection and localization in vast distance with possibility of real test in practice.The testing curcuits are used for measurement and results are processed for purpose of detection and localization of source. The measurement itself was made by testing curcuits and results were processed for purpose of detection and localization of source.
97

Optická detekce elektrogramů / Optical detection of electrograms

Hanák, Pavel January 2013 (has links)
The aim of the study was focused on problem of electrograms recording with using voltage sensitive dyes. Study of electrograms recording was extended with thema of optical detectors suitable for measurement and noise analysis. Elimination of noise and disturption was made in program Matlab; lowpass filtration and wavelet transformation was used. Application for electrograms analysis was developed in latter part of this work.
98

Vyhledávání úložných optických kabelů / Search storage of fiber optic cables

Čučka, Milan January 2014 (has links)
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.
99

Detekce průtoku pomocí optických interferenčních metod / Flow detection using optical intereference methods

Hoštáková, Nina January 2015 (has links)
The thesis deals with LSCI (Laser Speckle Contrast Imaging), an optical method utilizing laser speckle contrast for the estimation of blood flow changes. LSCI is non-invasive and technically not demanding approach, capabilities of which have not yet been fully exploited. The literature review part contains detailed description of the operating principle, imaging techniques, potential for medical applications with considering the limiting factors. The main aim of the thesis is to design and construct a complete LSCI system including appropriate phantoms able to simulate blood flow through the tissue. Imaging algorithms for the obtained data evaluation were implemented in Matlab® development enviroment. Finally, the created system was tested using different acquisition parameters as well as varying the image processing schemes. The resulting qualitative flow images were subsequently discussed and confronted with the theoretical assumptions.
100

Návrh optické sítě pro spojení bytových domů v Kojetíně / Designing of a Fiber Optic Network for Connecting Blocks of Flats in Kojetín

Rumplík, Martin January 2011 (has links)
The subject of this diploma's thesis is to create a design of a fiber optic network, which will allow an access to broadband internet connection for households living in blocks of flats in Kojetín. For this purpose the best technologies will be compared by analysis and the new network topology will be designed. The investor is a civic association Cyrilek.net that provides a wireless internet at this area. The best solution will be selected on the basis of financial and technical analysis and the investment will be calculated including its return. This innovation not only give people a really fast internet connection, but also the possibility of other services such as IPTV or VoIP.

Page generated in 0.0266 seconds