• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 117
  • 17
  • 1
  • Tagged with
  • 135
  • 77
  • 41
  • 32
  • 26
  • 16
  • 16
  • 15
  • 15
  • 15
  • 14
  • 14
  • 14
  • 13
  • 13
  • 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.
51

Vysokorychlostní filtrace síťového provozu / High-Speed Filtration of Network Traffic

Churý, Jan January 2017 (has links)
For high-speed (e.g. more than 1 Gbit/s) filtration of network traffic there are available many of proprietary hardware solutions nowadays. But there are also a couple of free licensed projects that are specialized in high-speed packet processing on common hardware. The goal of thesis is to find such projects, verify that there are filtering tools based on these projects, try to filter 10Gbit/s network traffic by these tools and test them against various filtration settings. Implementation of packet filter that could be used for filtration of network traffic up to 10Gbit/s speed should be the output of this thesis.
52

Využití filtru z nanovláken pro filtraci vzduchu / Use of nanofiber filter for air filtration

Straka, Petr January 2019 (has links)
The doctoral thesis „Using of nanofiber filter for air filtration“ is focused on application of nanofiber filter for air filtration under demanding conditions of water supply facilities. The main aim of the filter application is to decrease the secondary contamination of the indoor environment of the water accumulation tanks. The nanofiber filters are distinguished by high filtration efficiency of pollutants, dust particles and organic impurities. The contaminants don´t have to be unhealthy but they can be used for spore and microorganisms delivery to the system. They are served frequently as a reproduction substrate of microorganisms. All these factors negatively affect the water quality. The research includes formation of suitable testing methodology, pilot unit construction and operation, short-term testing and evaluation of nanofiber filters and commonly used filters and long term testing and verification of nanofiber filter attributes and quality. Furthermore the filter´s characteristics and filtration efficiency for characteristic pollutants were evaluated. Short-term and long-term experimental testing proved suitability of nanofiber filters use in water supply facilities. Interception of reported pollution indicators was reported on similar or higher level for application of nanofiber filter than for application of commonly used filter. Measured values of higher pressure difference of nanofiber filter were indicated as still adequate for use in water supply facilities. No operation difficulties, failures neither filter´s damage were reported during testing of nanofiber filters.
53

Potlačení strukturního šumu typu spekle / Speckle noise suppression

Kuchař, Otakar January 2018 (has links)
Master thesis deals with the study of ultrasound. The first part of this work is devoted to basic physical principles, imaging modes, ultrasound probes, biological effects and the last part is associated with the artifact associated with ultrasound waves. In the next part the specific noise called speckle noise is detaily discussed. The description includes both a mathematical and a statistical view. Several methods are described to eliminate this noise. In the practical part the described methods are realized and compared based on objective and subjective evaluation.
54

Filtrace signálů EKG s využitím vlnkové transformace / Wavelet filtering of ECG Signals

Ryšánek, Jan January 2012 (has links)
This work deals with the possibilities of filtering the ECG signal, representing the first part, which is the basis for successful delineation and follow diagnosis of the ECG signal. Filtration in this case is mean to suppress interference from electrical grid, noise of electrical grid. The content of the work is description of filters realized trough wavelet transform and linear filtering as a means to successful filtration of interference. There are method of stationary wavelet transform - dyadic wavelet transform, wavelet packet transform and wavelet wiener filtering method. Linear filtering includes two narrow-band FIR filters. The objective of this work is to propose different methods of wavelet and linear filters in Matlab, filtering of ECG signals and compare the success of filtration methods. ECG signals used in this work are from the CSE database.
55

Klasifikace dat leteckého laserového skenování v pískovcových skalních městech / Classification of Airborne Laser Scanning Data in Sandstone Landscapes

Tomková, Michaela January 2018 (has links)
Classification of Airborne Laser Scanning Data in Sandstone Landscapes Abstract This work is concerned with the classification of airborne laser scanning data in sandstone landscapes called "rock cities". Standard filters do not work reliably in such a rugged terrain covered with dense vegetation and in the results the rock formations are smoothed or even removed from the terrain. The method of classification suggested in this work is based on the procedure used in manual filtration. When exploring a sufficiently dense point cloud in 3D, one is able to distinguish rock formations from trees even though their shapes are similar. In contrast to trees, rock pillars are modeled only by points reflected off the surface and therefore they make concave elevations in the ground. Because of penetration of trees, there are points reflected off a treetop, branches, leaves and also ground under the tree. The proposed method segments a point cloud according to local minima in approximated surface and classifies these objects into classes rock, tree, and mix by inner point distribution. Objects in classes tree and mix are then filtered by lasground function from LAStools. The method was tested with merged point cloud consisted of data from the standard airborne laser scanning of the Czech Republic and experimental...
56

Separace aerosolových částic na polymerních membránách / Separation of aerosol particles using polymeric membranes

Morcinek, Tomáš January 2021 (has links)
This diploma thesis deals with the separation of aerosol particles on membranes from polypropylene hollow fibers. As a source of particles, a desktop 3D printer using polymer filaments was used. Filtration efficiency and a pressure drop on a hollow polypropylene fiber membrane and a high efficiency particulate filter (HEPA filter) were monitored during filtration of particles from 3D print using filaments of acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid and polyethylene terephthalate glycol at nearly the same air flow. The results achieved by both filer media are then compared and discussed. The results show that the hollow fiber membrane achieves better filtration efficiency at higher particle concentrations, while using the less emitting materials, the efficiency of the HEPA filter was higher or the same. The total filtration efficiency calculated from all experiments with all filaments was higher for the hollow fiber membrane with higher pressure drop at the same time.
57

Vlastnosti pěnokeramických filtrů potřebné pro využití v numerických simulacích / Properties of ceramics foam filters needed for numerical simulation software

Boček, Vítězslav January 2017 (has links)
Final thesis, elaborated within the master study field of Foundry technology, deals with determination of some parameters of ceramic foam filters that are necessary for using numerical simulation during foundry practice. Thesis foccuses on defining methodology, manufacturing messuring device and measuring pressure drop on several type sof ceramic foam filters in dependence on flow rate of measuring medium. Measuring medium selected is water, mening this thesis deals also with water simulation in foundry technology.
58

Metodika návrhu systému využití šedých vod ve vybraných objektech / Methodology of use greywater in the selected objects

Raček, Jakub Unknown Date (has links)
The concept of reusing wastewater in buildings has recently become more important. This is due to change in climatic conditions and reduction of the yield of water resources. Greywater can broadly be defined as not extremely polluted wastewater coming from basins, showers, baths, kitchen sinks and washing machines. The concept based on the use of alternative rate sources wouldn't need same strict parameters as drinking water. Dissertation engage in collecting greywater from basins, showers and wash machines separately from the other more polluted domestic wastewater at the dorms, the laundry machines, the hotels, detached houses, the swimming pools, the office buildings and other buildings. The research showed that membrane filtration meets all needed parameters of water quality and can be used in house systems where we use cleansed white water to flush toilets, watering garden or grass areas. There is still a lack of experience and documentation for such system of operation in our country. Systems of use of greywater in selected objects are detaily solved in my dissertation directed at system proposal.
59

Vektorizovaná mračna bodů pro mobilní robotiku / Vectorized Point Clouds for Mobile Robotics

Jelínek, Aleš January 2017 (has links)
Disertační práce se zabývá zpracováním mračenen bodů z laserových skenerů pomocí vektorizace a následnému vyhledávání korespondencí mezi takto získanými aproximacemi pro potřeby současné sebelokalizace a mapování v mobilní robotice. První nová metoda je určena pro segmentaci a filtraci surových dat a realizuje obě operace najednou v jednom algoritmu. Pro vektorizaci je představen optimalizovaný algoritmus založený na úplné metodě nejmenších čtverců, který je v současnosti patrně nejrychlejší ve své třídě a blíží se tak eliminačním metodám, které ovšem produkují výrazně horší aproxi- mace. Inovativní analytické metody jsou představeny i pro účely vyjádření podobnosti mezi dvěma vektorizovanými skeny, pro jejich optimální sesazení a pro vyhledávání korespondencí mezi nimi. Všechny představené algoritmy jsou intezivně testovány a jejich vlastnosti ověřeny množstvím experimentů.
60

Odhad kvality signálů EKG / ECG quality estimation

Vršková, Markéta January 2018 (has links)
This master thesis solves the problem of estimating the quality of ECG signals. The main objective of the work is to implement a self-assessment of the quality assessment method based on the studied methods for estimating the quality of the ECG signal. The theoretical part of the thesis contains mainly the description of the electrical activity of the heart, cardiac anatomy, and physiology, electrocardiography, various types of ECG signal interference and methods describing the estimation of ECG signal quality. The practical part deals with the application of individual methods for estimating the quality of ECG signals. The SNR (signal-to-noise ratio) calculation is used to continuously estimate the quality of the ECG. Signal quality can also be judged based on statistical functions, adaptive filtering, or by analyzing independent components. The proposed method is based on the calculation of the correlation coefficient between the adaptive template and the disturbed signal. The robustness of the method was verified on artificially created ECG signals with different noise levels and then on real signals from the MIT-BIH database.

Page generated in 0.0595 seconds