19 research outputs found

    Comparison of different electrocardiography with vectorcardiography transformations

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    This paper deals with transformations from electrocardiographic (ECG) to vectorcardiographic (VCG) leads. VCG provides better sensitivity, for example for the detection of myocardial infarction, ischemia, and hypertrophy. However, in clinical practice, measurement of VCG is not usually used because it requires additional electrodes placed on the patient's body. Instead, mathematical transformations are used for deriving VCG from 12-leads ECG. In this work, Kors quasi-orthogonal transformation, inverse Dower transformation, Kors regression transformation, and linear regression-based transformations for deriving P wave (PLSV) and QRS complex (QLSV) are implemented and compared. These transformation methods were not yet compared before, so we have selected them for this paper. Transformation methods were compared for the data from the Physikalisch-Technische Bundesanstalt (PTB) database and their accuracy was evaluated using a mean squared error (MSE) and a correlation coefficient (R) between the derived and directly measured Frank's leads. Based on the statistical analysis, Kors regression transformation was significantly more accurate for the derivation of the X and Y leads than the others. For the Z lead, there were no statistically significant differences in the medians between Kors regression transformation and the PLSV and QLSV methods. This paper thoroughly compared multiple VCG transformation methods to conventional VCG Frank's orthogonal lead system, used in clinical practice.Web of Science1914art. no. 307

    Využití softwarově definovaného rádia v oblasti SMART technologii

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    Modern telecommunication systems are rapidly evolving. This rapid development requires constant research and fast prototyping. This dissertation thesis focusses on deployment of software defined radio (SDR) in multiple application areas, including SMART technologies. SDR itself is a tool behind many breakthroughs in modern telecommunications, due to its major adaptability. It offers a comprehensive way of fast prototyping, which rely on suitable software platform. The field of telecommunications is ever-changing, due to the constant pressure on innovation. For this reason, it is desirable to test some of the alternative communication technologies. Visible light communication (VLC) system based on combination of virtual instrumentation and software defined radios was chosen for experimentation. This dissertation focusses on multiple versions of VLC system that were developed over the years. Each version is further discussed, and their advantages and disadvantages are presented. A draft of fourth and newest version is mentioned along with possible directions of the research. Results from multiple application areas are presented, which show the adaptability of the whole platform to different use cases including but not limited to: SMART technologies, automotive, nuclear waste disposal sites, or industry. It is demonstrated that the newest version of the system, which is based on OFDM modulation, can communicate up to 50 meters in closed environments and up to 35 meters in outdoor scenarios. This opens further research directions such as truck platooning or underwater communications.Moderní komunikační systémy jsou jednou z nejrychleji se rozvíjejících oblastí. Takového markantního posunu lze dosáhnout pouze skrze nový vývoj a aplikaci metodiky fast prototypingu. Tato disertace se zaměřuje na nasazení technologie softwarově definovaného rádia (SDR) v různých aplikačních oblastech. Samotné SDR je díky své adaptabilitě nástrojem, který stál na pozadí rozvoje mnoha moderních telekomunikačních systémů. Jedná se o ucelenou platformu pro fast prototyping, která se opírá o robustní softwarovou základnu. Právě telekomunikace jsou oblastí, kde je takové zařízení nedocenitelné, právě kvůli neustálému tlaku na inovace. Právě to je důvodem, proč je vhodné také testovat různé alternativní technologie pro přenos dat. Jednou z takových je komunikace viditelným spektrem světla (VLC), která je náplní této práce. Součástí praktické části je vývoj a popis několika verzí VLC systému založených na virtuální instrumentaci a SDR, které vznikly během autorova studia. Každá verze je samostatně popsána včetně výhod a nevýhod, které poskytují. Součástí je též první náčrt čtvrté verze, která bude součástí budoucího výzkumu. Prezentované výsledky z různých aplikačních oblastí jasně ukazují, že je celou platformu možné použít v různých aplikačních oblastech, včetně SMART technologií, automotive, úložišti jaderného odpadu anebo Průmyslu 4.0. Součástí jsou též výsledky z poslední verze, které dokazují, že je systém ve vnitřních prostorech komunikovat až na vzdálenost 50 metrů, zatímco ve venkovních podmínkách je to 35 metrů. Díky tomu je možné vytyčit nové oblasti výzkumu jako je například platooning (tandemová jízda) anebo podvodní komunikace.450 - Katedra kybernetiky a biomedicínského inženýrstvívyhově

    Individual Professional Practice in the Company

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    Import 03/11/2016Tato bakalářská práce se zabývá mou odbornou praxí ve společnosti ha-vel internet s.r.o., ve které jsem zaujímal pozici stážisty na technickém oddělení. V první části představím společnost jako takovou, čím se zabývá, na koho se orientuje. Navazuje popis mé pracovní náplně ve výše zmíněné společnosti. V závěru zmiňuji znalosti a dovednosti, které jsem v průběhu nabyl a také ty, které mi scházely. Nechybí ani mé dosažené výsledky a celkové zhodnocení praxe.This thesis describes my individual profesional practice in the company Ha-vel internet s.r.o, in which i worked as intern in technical department. In the beggining i describe company and its focus. Then i continue with description of my actual work. In the end i describe my knowledge and skills that i gained and missed during the practice. There are also my results and its overall evaluation.440 - Katedra telekomunikační technikyvýborn

    Komunikace viditelným světlem (VLC) pro LED veřejné osvětlení a další venkovní aplikace

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    This diploma thesis focuses on visible light communications, mainly in outdoor appliances. Whole text is divided into two blocks. First segment serves as a research, focusing on experiments carried by different university teams all over the world, which are published as IEEE conference papers. Another half discuss our own VLC prototyping, its limitations and possible upgrade paths.Tato práce se zabývá problematikou komunikace viditelným spektrem světla. Celý text je rozvržen do dvou velkých bloků, přičemž první slouží jako rešerše prací jiných týmů ze všech koutů světa, publikovaných na IEEE konferencích. Druhá část pojednává o samotném měření a prototypu komunikačního řetězce. Zmíněna je konstrukce, limitace i možnosti budoucích vylepšení.440 - Katedra telekomunikační technikyvýborn

    Visible light communication system based on software defined radio: Performance study of intelligent transportation and indoor applications

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    In this paper, our first attempt at visible light communication system, based on software defined radio (SDR) and implemented in LabVIEW is introduced. This paper mainly focuses on two most commonly used types of LED lights, ceiling lights and LED car lamps/tail-lights. The primary focus of this study is to determine the basic parameters of real implementation of visible light communication (VLC) system, such as transmit speed, communication errors (bit-error ratio, error vector magnitude, energy per bit to noise power spectral density ratio) and highest reachable distance. This work focuses on testing various multistate quadrature amplitude modulation (M-QAM). We have used Skoda Octavia III tail-light and Phillips indoor ceiling light as transmitters and SI PIN Thorlabs photodetector as receiver. Testing method for each light was different. When testing ceiling light, we have focused on reachable distance for each M-QAM variant. On the other side, Octavia tail-light was tested in variable nature conditions (such as thermal turbulence, rain, fog) simulated in special testing box. This work will present our solution, measured parameters and possible weak spots, which will be adjusted in the future.Web of Science84art. no. 43

    Occupancy detection in smart home space using interoperable building automation technologies

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    To detect whether people are occupying individual rooms in a smart home, a range of sensors and building automation technologies can be employed. For these technologies to function in tandem and exchange useful data in a smart home environment, they must be interoperable. The article presents a new interoperable solution which combines existing decentralized KNX building automation technology with a KNX/LabVIEW software application gateway using visible light communication to track occupancy in a room. The article also describes a novel KNX/IoT software application gateway which uses an MQTT protocol for interoperability between KNX technology and IBM Watson IoT platform. We conducted an experiment with the originally designed solution to detect occupancy in an office room. We used KNX and BACnet building automation technology to produce an interoperable KNX/BACnet hardware gateway which allowed the application of artificial neural network mathematical methods for CO2 waveform prediction. The best results in detecting occupancy in a room were R = 0.9548 (Levenberg-Marquardt algorithm), R = 0.9872 (Bayesian regularization algorithm), and R = 0.8409 (scaled conjugate gradient algorithm), which correspond to the results obtained by other authors and a minimum system prediction accuracy of 96%.Web of Science12art. no. 4

    Fiber-optic Bragg system for the dynamic weighing of municipal waste: A pilot study

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    The publication focus on a pilot study (design, implementation and verification) of a dynamic weighing system designed for weighing of municipal waste during the dumping of garbage containers. The presented solution is based on fiber Bragg gratings (FBG) and can be additionally implemented into the lifting equipment of commonly employed garbage trucks. The weighing principle is based on the measurement of deformation effect and vibration response of the lifting equipment during the dumping of garbage bins. The measuring system leverages the advantages of power measurement, which use the conversion of the spectral shift of modulated light signal during the measurement to the change in optical power of a pair of spectral overlapping Bragg gratings. Two different methods are presented and discussed: the amplitude method, which analyze the maximum amplitude change of the signal and/or the method, which analyze the time period of the dampened oscillation of the lifting device. Due to the small dimensions, the complete system can be installed together with FBG sensors directly onto the lifting device. The pilot tests of the presented system were carried out for over 4 months, showing an accuracy of up to +/- 4.04 kg in the range of 10-100 kg for standardized containers used for municipal waste. The system worked in completely standalone mode and the garbage trucks were not modified in any inconvenient way.Web of Science9990599905

    Enhancements of SDR-based FPGA system for V2X-VLC communications

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    This pilot study focuses on a real measurements and enhancements of a software defined radio-based system for vehicle-to everything visible light communication (SDR-V2X-VLC). The presented system is based on a novel adaptive optimization of the feed-forward software defined equaliza-tion (FFSDE) methods of the least mean squares (LMS), normalized LMS (NLMS) and QR decomposition-based recursive least squares (QR-RLS) algorithms. Individual parameters of adaptive equalizations are adjusted in real-time to reach the best possible results. Experiments were carried out on a conventional LED Octavia III taillight drafted directly from production line and universal software radio peripherals (USRP) from National Instruments. The transmitting/receiving elements used multistate quadrature amplitude modulation (M-QAM) implemented in LabVIEW programming environment. Experimental results were verified based on bit error ratio (BER), error vector magnitude (EVM) and modulation error ratio (MER). Experimental results of the pilot study unambiguously confirmed the effectiveness of the pro-posed solution (longer effective communication range, higher immunity to interference, deployment of higher state QAM modulation formats, higher transmission speeds etc.), as the adaptive equalization significantly improved BER, MER and EVM parameters. The best results were achieved using the QR-RLS algorithm. The results measured on deployed QR-RLS algorithm had significantly better Eb/N0 (improved by approx. 20 dB) and BER values (difference by up to two orders of magnitude).Web of Science6833652362

    Design of an IoT-based monitoring system as a part of prevention of thermal events in mining and landfill waste disposal sites: A pilot case study

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    This case study deals with the design of a hybrid system for the prevention of thermal events in mining waste disposal sites and landfills. The overall design, real imple mentation, optimization, and experimental verification of the functionality of the entire system are described in detail. Both experimental platforms are built on the Internet of Things (long range wide area network (LoRaWAN) and Sigfox) basis and meet the conditions for autonomous long-term on-site monitoring. The data collected are periodically transmitted wirelessly to a database repository, which processes relevant parameters for the operators of dispatching workplaces. The study is focused on a combination of surface and depth measurement methods. The experimental results clearly confirm the functionality of the proposed solutions, which will enable timely interventions and elimination of underground and surface combustions. Thanks to centralized data collection, a unique database has also been created, which can be used for the implementation of prediction algorithms (based, for example, on machine learning or artificial intelligence).Web of Science72art. no. 550011

    Review of fundamental active current extraction techniques for SAPF

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    The field of advanced digital signal processing methods is one of the fastest developing scientific and technical disciplines, and is important in the field of Shunt Active Power Filter control methods. Shunt active power filters are highly desirable to minimize losses due to the increase in the number of nonlinear loads (deformed power). Currently, there is rapid development in new adaptive, non-adaptive, and especially hybrid methods of digital signal processing. Nowadays, modern methods of digital signal processing maintain a key role in research and industrial applications. Many of the best practices that have been used to control shunt active power in industrial practice for decades are now being surpassed in favor of new progressive approaches. This systematic research review classifies the importance of using advanced signal processing methods in the field of shunt active power filter control methods and summarizes the extant harmonic extraction methods, from the conventional approach to new progressive methods using genetic algorithms, artificial intelligence, and machine learning. Synchronization techniques are described and compared as well.Web of Science2220art. no. 798
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