Počet nalezených dokumentů: 208
Publikováno od do

SUPER-RESOLUTION MICROSCOPY LIVE CELL IMAGING AND IMAGE ANALYSIS
Klíma, Miloš; Fliegel, Karel; Lasser, Theo; Lukeš, Tomáš
2017 - anglický
Novel fundamental research results provided new techniques going beyond the diffraction limit. These recent advances known as super-resolution microscopy have been awarded by the Nobel Prize as they promise new discoveries in biology and live sciences. All these techniques rely on complex signal and image processing. The applicability in biology, and particularly for live cell imaging, remains challenging and needs further investigation. Focusing on image processing and analysis, the thesis is devoted to a significant enhancement of structured illumination microscopy (SIM) and super-resolution optical fluctuation imaging (SOFI)methods towards fast live cell and quantitative imaging. The thesis presents a novel image reconstruction method for both 2D and 3D SIM data, compatible with weak signals, and robust towards unwanted image artifacts. This image reconstruction is efficient under low light conditions, reduces phototoxicity and facilitates live cell observations. We demonstrate the performance of our new method by imaging long super-resolution video sequences of live U2-OS cells and improving cell particle tracking. We develop an adapted 3D deconvolution algorithm for SOFI, which suppresses noise and makes 3D SOFI live cell imaging feasible due to reduction of the number of required input images. We introduce a novel linearization procedure for SOFI maximizing the resolution gain and show that SOFI and PALMcan both be applied on the same dataset revealing more insights about the sample. This PALMand SOFI concept provides an enlarged quantitative imaging framework, allowing unprecedented functional exploration of the sample through the estimation of molecular parameters. For quantifying the outcome of our super-resolutionmethods, the thesis presents a novel methodology for objective image quality assessment measuring spatial resolution and signal to noise ratio in real samples. We demonstrate our enhanced SOFI framework by high throughput 3D imaging of live HeLa cells acquiring the whole super-resolution 3D image in 0.95 s, by investigating focal adhesions in live MEF cells, by fast optical readout of fluorescently labelled DNA strands and by unraveling the nanoscale organization of CD4 proteins on a plasma membrane of T-cells. Within the thesis, unique open-source software packages SIMToolbox and SOFI simulation tool were developed to facilitate implementation of super-resolution microscopy methods. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
SUPER-RESOLUTION MICROSCOPY LIVE CELL IMAGING AND IMAGE ANALYSIS

Novel fundamental research results provided new techniques going beyond the diffraction limit. These recent advances known as super-resolution microscopy have been awarded by the Nobel Prize as they ...

Klíma, Miloš; Fliegel, Karel; Lasser, Theo; Lukeš, Tomáš
České vysoké učení technické v Praze, 2017

Example-based Rendering of Hand-drawn Content
Sýkora, Daniel; Fišer, Jakub
2017 - anglický
In this dissertation, we focus on the capabilities of example-based synthesis with a particular interest in hand-drawn appearance. We propose several approaches for creating new digital imagery from examples without making any domain-speci c assumptions and being media-agnostic. New methods for content-creation and non-photorealistic stylization are presented together with examples of their practical usage in contemporary digital production pipelines. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Example-based Rendering of Hand-drawn Content

In this dissertation, we focus on the capabilities of example-based synthesis with a particular interest in hand-drawn appearance. We propose several approaches for creating new digital imagery from ...

Sýkora, Daniel; Fišer, Jakub
České vysoké učení technické v Praze, 2017

Local navigation methods for metal detectors
Ripka, Pavel; Roháč, Jan; Nováček, Petr
2017 - anglický
This dissertation addresses the implementation of navigation capabilities for metal detection, in particular landmines. The precise aim of this thesis is to find a professional handheld metal detector search head position. This allows the creation of a magnetic image of the area searched, which opens a new prospective to increase the discrimination ability of metal detection between conductive scrap and the surveillance of unexploded ordnance. This thesis has two parts. The first and main part focuses on the enhancement of professional handheld metal detector discrimination functionality. This was the main stream of my research work. The second part deals with position estimation as a tool to reach the objectives of the first part. The navigation is based on low-cost MEMS inertial sensors of angular rate and acceleration, which have minimum metal content. The required precision, in centimetres, can only be achieved by using calibration and signal enhancement procedures. The utilization of the magnetic position markers directly detected by a metal detector itself is my main original scientific contribution to the knowledge in the scientific area of aiding navigation. Position markers with specific characteristics are placed in a known location and are recognised by a metal detector during its overhead movement. The metal position markers described are a connection link between the navigation part and the part dealing with metal detector enhancement. Their usage is only enabled due to previous research made on the signal dependency of the metal detector’s output on a detected object’s material, size and distance from the detector’s search head. Metal position markers are a by-product of this research, which focuses in particularly on the improvement of metal detector discrimination abilities. The ability of metal detector discrimination can also be increased by using several excitation signal frequencies. The methods published up to now use multitone signals composed of sinewaves with two to four frequencies. In the presented papers we show that using sin(x)/x excitation signal brings new possibilities in this area.Tato dizertacní práce se zabývá implementací navigacních schopností na detektory kovových predmetu a zejména min. Urcení pozice detekcní hlavy profesionálního detektoru kovu je presný cíl této dizertacní práce. Známá pozice umožní vytvorení magnetického obrazu zkoumané oblasti a tím zvýší diskriminacní schopnost detektoru kovu odlišit nevybuchlou munici od vodivého odpadu. Dizertacní práce má dve cástí. První, hlavní cást, je zamerena na zvýšení diskriminacních schopností profesionálního rucního detektoru kovu. Toto byl hlavní smer mé výzkumné cinnosti. Druhá cást se zabývá odhadem pozice detektoru jako nástroje k dosažení cíle první cásti práce. Navigacní schopnost je založena na využití levných inerciálních senzoru typu MEMS merících zrychlení a úhlovou rychlost, u kterých byl kladen duraz na minimální obsah kovu. Vyžadované presnosti jednoho centimetru je možné dosáhnout pouze za pomoci kalibrace a zpresnujících postupu. Využití magnetických pozicních znacek prímo detekovaných detektorem kovu je mým vlastním vedeckým prínosem vedecké znalosti v oblasti navigacního zpresnování. Popisované kovové pozicní znacky jsou pojítkem mezi navigacní cástí a cástí zabývající se vylepšením detektoru kovu. Jejich využití je umožneno pouze díky predchozímu výzkumu provádeného na závislosti výstupního signálu detektoru kovu na materiálu detekovaného objektu, jeho velikosti a vzdálenosti od detekcní hlavy detektoru kovu. Kovové pozicní znacky jsou vedlejším produktem tohoto výzkumu, který cílil predevším na zvýšení diskriminacních schopností detektoru kovu. Zvýšení diskriminacních schopností detektoru kovu muže být dále docíleno i za pomoci využití více frekvencí použitých v budícím signálu. Publikované metody využívají více tónového signálu vytvoreného ze sinusoid o dvou až ctyrech frekvencích. V prezentovaných výsledcích jsme ukázali, že využití sin (x)/x budicího signálu prináší nové možnosti v této oblasti. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Local navigation methods for metal detectors

This dissertation addresses the implementation of navigation capabilities for metal detection, in particular landmines. The precise aim of this thesis is to find a professional handheld metal ...

Ripka, Pavel; Roháč, Jan; Nováček, Petr
České vysoké učení technické v Praze, 2017

Short-Term Visual Object Tracking in Real-Time
Matas, Jiří; Vojíř, Tomáš
2017 - anglický
In the thesis, we propose two novel short-term object tracking methods, the Flock of Trackers (FoT) and the Scale-Adaptive Mean-Shift (ASMS), a framework for fusion of multiple trackers and detector and contributions to the problem of tracker evaluation within the Visual Object Tracking (VOT) initiative. The Flock of Trackers partitions the object of interest to an equally sized parts. For each part, the FoT computes an optical flow correspondence and estimates its reliability. Reliable correspondences are used to robustly estimates a target pose using RANSAC technique, which allows for range of complex rigid transformation (e.g. affine transformation) of a target. The scale-adaptive mean-shift tracker is a gradient optimization method that iteratively moves a search window to the position which minimizes a distance of a appearance model extracted from the search window to the target model. The ASMS propose a theoretically justified modification of the mean-shift framework that addresses one of the drawbacks of the mean-shift trackers which is the fixed size search window, i.e. target scale. Moreover, the ASMS introduce a technique that incorporates a background information into the gradient optimization to reduce tracker failures in presence of background clutter. To take advantage of strengths of the previous methods, we introduce a novel tracking framework HMMTxD that fuses multiple tracking methods together with a proposed feature-based online detector. The framework utilizes a hidden Markov model (HMM) to learn online how well each tracking method performs using sparsely ”annotated” data provided by a detector, which are assumed to be correct, and confidence provided by the trackers. The HMM estimates the probability that a tracker is correct in the current frame given the previously learned HMM model and the current tracker confidence. This tracker fusion alleviates the drawbacks of the individual tracking methods since the HMMTxD learns which trackers are performing well and switch off the rest. All of the proposed trackers were extensively evaluated on several benchmarks and publicly available tracking sequences and achieve excellent results in various evaluation criteria. The FoT achieved state-of-the-art performance in the VOT2013 benchmark, finishing second. Today, the FoT is used as a building block in complex applications such as multi-object tracking frameworks. The ASMS achieved state-of-the-art results in the VOT2015 benchmark and was chosen as the best performing method in terms of a trade-off between performance and running time. The HMMTxD demonstrated state-of-the-art performance in multiple benchmarks (VOT2014, VOT2015 and OTB). The thesis also contributes, and provides an overview, to the Visual Object Tracking (VOT) evaluation methodology. This methodology provides a means for unbiased comparison of different tracking methods across publication, which is crucial for advancement of the state-of-the-art over a longer timespan and also provides a tools for deeper performance analysis of tracking methods. Furthermore, a annual workshops are organized on major computer vision conferences, where the authors are encouraged to submit their novel methods to compete against each other and where the advances in the visual object tracking are discussed. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Short-Term Visual Object Tracking in Real-Time

In the thesis, we propose two novel short-term object tracking methods, the Flock of Trackers (FoT) and the Scale-Adaptive Mean-Shift (ASMS), a framework for fusion of multiple trackers and detector ...

Matas, Jiří; Vojíř, Tomáš
České vysoké učení technické v Praze, 2017

Multi-view Facial Landmark Detection
Franc, Vojtěch; Uřičář, Michal
2017 - anglický
In this thesis, we tackle the problem of designing a multi-view facial landmark detector which is robust and works in real-time on low-end hardware. Our landmark detector is an instance of the structured output classi ers describing the face by a mixture of tree based Deformable Part Models (DPM). We propose to learn parameters of the detector by the Structured Output Support Vector Machine algorithm which, in contrast to existing methods, directly optimizes a loss function closely related to the standard evaluation metrics used in landmark detection. We also propose a novel two-stage approach to learn the multi-view landmark detectors, which provides better localization accuracy and signi cantly reduces the overall learning time. We propose several speedups that enable to use the globally optimal prediction strategy based on the dynamic programming in real time even for dense landmark sets. The empirical evaluation shows that the proposed detector is competitive with the current state-ofthe- art both regarding the accuracy and speed. We also propose two improvements of the Bundle Method for Regularized Risk Minimization (BMRM) algorithm which is among the most popular batch solvers used in structured output learning. First, we propose to augment the objective function by a quadratic prox-center whose strength is controlled by a novel adaptive strategy preventing zig-zag behavior in the cases when the genuine regularization term is weak. Second, we propose to speed up convergence by using multiple cutting plane models which better approximate the objective function with minimal increase in the computational cost. Experimental evaluation shows that the new BMRM algorithm which uses both improvements speeds up learning up to an order of magnitude on standard computer vision benchmarks, and 3 to 4 times when applied to the learning of the DPM based landmark detector. v Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Multi-view Facial Landmark Detection

In this thesis, we tackle the problem of designing a multi-view facial landmark detector which is robust and works in real-time on low-end hardware. Our landmark detector is an instance of the ...

Franc, Vojtěch; Uřičář, Michal
České vysoké učení technické v Praze, 2017

Enhancement of the selected management and planning quality control tools
Mach, Pavel; Žák, Vratislav; Povolotskaya, Evgenia
2017 - anglický
A detailed analysis of three management and planning quality control tools – affinity diagram, arrow diagram and process decision program chart – was performed. Then fuzzy logic was used for increase the yield of information of these tools. All three tools shown up to be flexible for fuzzy approach application. As the first, an application of an arrow diagram with a support of fuzzy logic to solution of mobile phone functionality problem at a service center for repair of mobile phones is presented. For the smooth course of negotiation between a client and the mobile phone reparation service there is a need to estimate the time of the problem solution as precisely as possible. Fuzzy logic as a supporter for an arrow diagram was used in order to determine the time interval of mobile reparation process more accurately in comparison with a standard approach. Better estimation of the time of a step “Diagnostics with the goal to find a cause of a problem” using the fuzzy logic is demonstrated. Then, an affinity diagram formed for a process of adhesive assembly of electronic components on the printed circuit board was constructed. Fuzzy approach showed the degree of an influence of the failures in some operations of the process to the failures in the following operations of this process. Non-obvious failures that could be met during a testing step were estimated and their significance was calculated. Process decision program chart (PDPC) created for assembly of electronic components on a printed circuit board based on wave soldering was also presented. The process decision program chart was constructed to identify risks and develop counter-measures (preventive actions). Volume of information, which should be involved into such the diagram, is very high. Fuzzy approach was used to find information of lower importance, which can occur, and thereby reduce the amount of entering information for processing of the PDPC diagram. The use of fuzzy logic is, with respect to the range of the thesis, documented on selected steps used in the processing of selected managerial quality control tools. The approach is generic and can be used for any technological or other type of an operation or a process to obtain deeper insight into the problem and better estimation of the course of an event under analysis. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Enhancement of the selected management and planning quality control tools

A detailed analysis of three management and planning quality control tools – affinity diagram, arrow diagram and process decision program chart – was performed. Then fuzzy logic was used for increase ...

Mach, Pavel; Žák, Vratislav; Povolotskaya, Evgenia
České vysoké učení technické v Praze, 2017

Identification of femtocells in mobile networks
Bešťák, Robert; Sedláček, Marek
2017 - anglický
The evolving mobile networks are requested to convey increasing data traffic as popularity of online services together with affordability of mobile devices is growing. One solution to mobile carriers, which can help them quickly deploy small base stations (BS) ensuring great indoor coverage with minimum costs, and high data rate capability, is femtocell technology. However, standard deployment techniques are unsatisfactory for these type of BSs. There are two main reasons for that. Firstly, femtocells will be deployed in great numbers. Secondly, they are deployed by users and are portable. It means their position is not known in advance, and can vary in time. Therefore, femtocells have to implement self-configuration principles. Physical Cell Identity is one of the most important parameters to be chosen automatically under defined conditions. It is crucial parameter, which allows them to convey a communication between a user equipment and a core network. A study on Physical Cell Identity issues in mobile networks with femtocells is presented in my thesis. For this purpose, I created two different models of femtocells deployment and deal with a collision and a confusion. They are two main problems, which threaten proper Physical Cell Identity assignment in mobile networks. Outputs of the thesis serves for better understanding of interrelations between differently placed femtocells in term of collision and confusion issue and as the basis to design the framework handling Physical Cell Identity allocation. The simulations conducted on proposed models were utilized to obtain probability characteristics and indicators based on graph theory. In the evaluation section, I appoint several characteristics as probability of collision, probability of confusion and maximal number of neighbourhood cells and some others to support solution of collision and confusion issue. I use results of evaluation and layout the framework for automated Physical Cell Identity assignment with two different approaches, the distributed one, and the centralized one. Since, femtocells are subcategory of small cells so findings, mentioned in this thesis, can also be used for other types of small cells. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Identification of femtocells in mobile networks

The evolving mobile networks are requested to convey increasing data traffic as popularity of online services together with affordability of mobile devices is growing. One solution to mobile carriers, ...

Bešťák, Robert; Sedláček, Marek
České vysoké učení technické v Praze, 2017

Algorithms for Complex Bipedal Walking
Čelikovský, Sergej; Dolinský, Kamil
2017 - anglický
This thesis studies the problem of parameter estimation, model identi- fication and state estimation for underactuated bipedal walking robots. Two main results were developed. The first result is a novel identification method suited for this problem. The second result is the extension of existing algorithms for state estimation to the case of the hybrid model of an underactuated walking robot. The identification method takes advantage of the linear structure of the model with respect to estimated parameters. The resulting estimator is calculated iteratively and maximizes the likelihood of the data. The method was tested on both simulated and experimental data. Simulations were carried out for an underactuated walking robot with a distance meter to measure absolute orientation. Laboratory experiments were carried out on a leg of a laboratory walking robot model equipped with a threeaxis accelerometer and gyroscope to measure absolute orientation. The method performs favorably in comparison with other benchmark estimation algorithms and both the simulations and the laboratory experiments con rmed its high potential for the use in identi cation of underactuated robotic walkers. The state estimators were applied to estimate the absolute orientation of an underactuated walking robot in the presence of impacts which occur when the leg of the robot hits the ground. The proposed estimation scheme was tested on simulations of a 3-link robot and shows that proposed extensions yields improved estimation performance. Klíčová slova: walking robots; maximum likelihood estimation; identification; state estimation Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Algorithms for Complex Bipedal Walking

This thesis studies the problem of parameter estimation, model identi- fication and state estimation for underactuated bipedal walking robots. Two main results were developed. The first result is a ...

Čelikovský, Sergej; Dolinský, Kamil
České vysoké učení technické v Praze, 2017

Measurement of fast-flying targets in near-zone
Hudec, Přemysl; Jeník, Vojtěch
2017 - anglický
This thesis deals with the problem of detection, identification and tracking of fast flying objects close to radar sensors, which reflects a current set-up in radar based active defense systems (ADS). Furthermore, a comprehensive noise analysis of CW radar is presented. Various configurations of CW radar are proposed and evaluated – from multiple installations of identical CW radar sensors to a set of receivers sharing the same HW component (e.g. local oscillator or the whole transmitter) – with the aim of finding the best and simplest possible configuration to fulfill the demanding requirements of ADS. Since the radar sensors are very complicated systems, the best solution cannot be identified without considering individual requirements on the system and available technology (i.e. frequency range, modulation, etc.). Therefore the thesis only concludes the principal properties of the proposed configurations. Another topic investigates available methods for in-field radar sensor testing and calibration. With regard to various methods and their limitations, the selected solution uses an antenna with an electronically controlled phase shifter and short-end stub. The last part is dedicated to the comprehensive noise analysis of a homodyne CW radar system with quadrature demodulation, which includes the amplitude and phase noise of local oscillator, noise of linear and quasi-linear RF components and noise of low frequency circuits. Even though the analysis has been developed on homodyne CW radar, the results are applicable to a much wider range of CW radar sensors. The follow-up research into this topic may be focused on behavior of SDR-based radar systems. Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Measurement of fast-flying targets in near-zone

This thesis deals with the problem of detection, identification and tracking of fast flying objects close to radar sensors, which reflects a current set-up in radar based active defense ...

Hudec, Přemysl; Jeník, Vojtěch
České vysoké učení technické v Praze, 2017

Reliability of optical structures in harsch environments
Zvánovec, Stanislav; Komanec, Matěj; Bohata, Jan
2017 - anglický
Networks of decades-old optical fibers created for operating optical communications are still in use today and being applied to the harsh environments of avionics and military, marine, and space systems. Consequently, an analysis of optical component reliability and a description of the aging process is called to predict the behavior of these fibers in specific areas of utilization. In this thesis, harsh environments for optical components are investigated and a methodology for the long-term monitoring of optical fiber parameters for different service conditions is presented. Furthermore, several optical systems are tested over aged optical infrastructure. Klíčová slova: optical fiber; harsh environment; aging; radio over fiber; free-space optics Plné texty jsou dostupné v digitálním repozitáři ČVUT.
Reliability of optical structures in harsch environments

Networks of decades-old optical fibers created for operating optical communications are still in use today and being applied to the harsh environments of avionics and military, marine, and space ...

Zvánovec, Stanislav; Komanec, Matěj; Bohata, Jan
České vysoké učení technické v Praze, 2017

O službě

NUŠL poskytuje centrální přístup k informacím o šedé literatuře vznikající v ČR v oblastech vědy, výzkumu a vzdělávání. Více informací o šedé literatuře a NUŠL najdete na webu služby.

Vaše náměty a připomínky posílejte na email nusl@techlib.cz

Provozovatel

http://www.techlib.cz

Facebook

Zahraniční báze