Traffic Density Monitoring Using Fiber Bragg Grating Sensors

Optická vlákna s Braggovskými mřížkami slouží nejen pro telekomunikační účely, ale také pro účely senzorické a postupně nahrazují dříve používané technologie. Tato diplomová práce je zaměřena na monitorování hustoty automobilové dopravy. Cílem je výroba a otestování mobilního měřícího pásu s FBG senzorem v reálném provozu. Nejprve je zpracována teoretická část, ve které je provedena rešerše na danou problematiku a následně je popsán celý průběh výroby od výběru materiálů, přes experimentální pásy testované na teplotní, ohybové a deformační vlastnosti až po výrobu finálního pásu. Dále jsou v práci zpracovány dlouhodobá měření, na kterých byla ověřena funkčnost výsledného měřícího pásu. Práce obsahuje popis postupu zpracování dat a provedenou analýzu hustoty dopravy.Bragg gratings optical fibers serve not only for telecommunication purposes but also for sensory purposes and gradually replace previously used technologies. This diploma thesis is focused on monitoring car traffic density. The aim is to produce and test a mobile measuring belt with FBG sensor in the condition of real traffic. In the first, theoretical part, a research on the given issue is performed and the whole process of production from choosing the materials through experimental belts tested on temperature, bending, and deformation qualities, to production of the final belt is described. Further, long-term measurements are performed, on which the funcionality of the final measuring belt was tested. The thesis contains the description of data processing method and performed analysis of the traffic density.440 - Katedra telekomunikační technikyvýborn

Individual Professional Practice in the Company

Tato bakalářská práce je o mém působení ve firmě EZconn Czech a.s. V první části jsou popsané informace o firmě EZconn Czech a.s. Popisuji zde její zaměření v telekomunikačních technologiích a optických komunikacích. Dále jsou zde uvedeny hlavní teoretické znalosti, které jsem získal a použil při řešení projektu. A nakonec popisuji postup realizace zadaného projektu. Projekt má za cíl návrh součástky, který bude sloužit k testování optické diody a tím bude moc dioda být uvedena do sériové výroby. Popisuji zde postupně výběr komponent, návrh zapojení obvodu, určení hodnot součástek a postup návrhu PCB desky. Nakonec je zde vyobrazený výsledek mé práce, který byl otestován v praktickém provozu.This bachelor thesis deals with my work at the company called EZconn Czech a.s. In the first part there is information about the company EZconn Czech a.s. I describe its focus in telecommunication technologies and optical communication. I mention also the most important theoretical knowledge I gained and later used during my work on the project. Finally, I describe the process of the project realisation. The aim of the project is to suggest a component which will serve for testing of optic diode. After the testing, the diode will be available for serial production. I describe the components selection, connection of circuit suggestion, components values determination, and the working procedure of PCB board suggestion. Finally, there are pictures of the outcome of my work, which was tested in practical operation.440 - Katedra telekomunikační technikydobř

Alternative approaches to measurement of ground vibrations due to the vibratory roller: A pilot study

At present, one of the primary tasks of the construction industry is to build transport infrastructure. This concerns both the construction of new bypasses of towns and the repair of existing roads, which are damaged by congestion, especially by freight transport. Whether it is a new building or a reconstruction, it is always very important to choose a suitable method of subsoil treatment. One of the most commonly used methods for soil treatment is currently compaction using vibratory rollers. This method is very effective both in terms of results and due to its low financial demands compared to other methods. Vibration is transmitted to the surrounding rock environment when compacting the subsoil using vibratory rollers. Although the intensity of these vibrations is not as pronounced as in other methods of subsoil treatment, such vibrations can have a significant effect, for example during compaction in urban areas or in an area with the presence of historical objects. Therefore, it is very advisable to monitor the effect of these vibrations on the environment during construction. This paper brings an original experimental comparative study of standard seismic instrumentation with a developed interferometric sensor for the field of monitoring vibrations generated during compaction of subsoil using vibrating rollers. The paper presents time and frequency domain results, as well as attenuation curves, which represent real attenuation of vibrations in a given rock environment. The results presented here show that a system operating on a different physical principle from the one used at present has the potential to replace the existing, very expensive, seismic equipment.Web of Science1924art. no. 542

Portable optical fiber Bragg grating sensor for monitoring traffic density

The paper examines the development of a portable sensor strip with fiber optic Bragg grating for monitoring urban traffic density up to 80 kph. It contains a 2.5-m-long and a 2-cm-high sensor created from a combination of silicone addition rubber (bicomponent addition silicone rubber) and Bragg grating placed inside a carbon tube. The design of the portable sensor permits traffic density and cars crossings to be monitored and detected in a single lane. The functionality of the sensor was verified in real traffic; the results of this study are based on the detection of 1518 vehicles of different types and sizes. According to the measurements, the sensor is characterized by a high detection rate of 98.946%.Web of Science922art. no. 479

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

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

Pressure membrane FBG sensor realized by 3D technology

The publication describes the design, production, and practical verification of an alternative pressure sensor suitable for measuring the pressure of gas, based on a combination of fiber-optic technology and 3D printing methods. The created sensor uses FBG (Fiber Bragg Grating) suitably implemented on a movable membrane. The sensor is equipped with a reference FBG to compensate for the effect of ambient temperature on the pressure measurement. The sensor is characterized by its immunity to EM interference, electrical passivity at the measuring point, small size, and resistance to moisture and corrosion. The FBG pressure sensor has a pressure sensitivity of 9.086 pm/mbar in the range from 0 to 9 mbar with a correlation coefficient of 0.9982. The pressure measurement in the specified range shows an average measurement error of 0.049 mbar and a reproducibility parameter of 0.0269 +/- 0.0135 mbar.Web of Science2115art. no. 515

Higher borides and oxygen-enriched Mg-B-O inclusions as possible pinning centers in nanostructural magnesium diboride and the influence of additives on their formation

The study of high pressure (2 GPa) synthesized MgB2-based materials allows us to conclude that higher borides (with near MgB12 stoichiometry) and oxygen-enriched Mg-B-O inclusions can be pinning centers in nanostructural magnesium diboride matrix (with average grain sizes of 15-37 nm). It has been established that additions of Ti or SiC as well as manufacturing temperature can affect the size, amount and distribution of these inclusions in the material structure and thus, influence critical current density. The superconducting behavior of materials with near MgB12 stoichiometry of matrix is discussed.Comment: 4 pages, 1 figues, presented at VORTEX VI-2009, accepted for Physica

Impact of COVID-19 Pandemic on TAVR Activity: A Worldwide Registry

Background: The COVID-19 pandemic had a considerable impact on the provision of structural heart intervention worldwide. Our objectives were: 1) to assess the impact of the COVID-19 pandemic on transcatheter aortic valve replacement (TAVR) activity globally; and 2) to determine the differences in the impact according to geographic region and the demographic, development, and economic status of diverse international health care systems. Methods: We developed a multinational registry of global TAVR activity and invited individual TAVR sites to submit TAVR implant data before and during the COVID-19 pandemic. Specifically, the number of TAVR procedures performed monthly from January 2019 to December 2021 was collected. The adaptive measures to maintain TAVR activity by each site were recorded, as was a variety of indices relating to type of health care system and national economic indices. The primary subject of interest was the impact on TAVR activity during each of the pandemic waves (2020 and 2021) compared with the same period pre–COVID-19 (2019). Results: Data were received from 130 centers from 61 countries, with 14 subcontinents and 5 continents participating in the study. Overall, TAVR activity increased by 16.7% (2,337 procedures) between 2018 and 2019 (ie, before the pandemic), but between 2019 and 2020 (ie, first year of the pandemic), there was no significant growth (–0.1%; –10 procedures). In contrast, activity again increased by 18.9% (3,085 procedures) between 2020 and 2021 (ie, second year of the pandemic). During the first pandemic wave, there was a reduction of 18.9% (945 procedures) in TAVR activity among participating sites, while during the second and third waves, there was an increase of 6.7% (489 procedures) and 15.9% (1,042 procedures), respectively. Further analysis and results of this study are ongoing and will be available at the time of the congress. Conclusion: The COVID-19 pandemic initially led to a reduction in the number of patients undergoing TAVR worldwide, although health care systems subsequently adapted, and the number of TAVR recipients continued to grow in subsequent COVID-19 pandemic waves. Categories: STRUCTURAL: Valvular Disease: Aorti