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Search results for: MASSIVE MIMO
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THE SYNCHROSQUEEZING METHOD IN BEARING ESTIMATION OF STATIONARY SIGNALS FOR PASSIVE SONAR WITH TOWED ARRAY
PublicationIn this paper, a novel method of bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of bearing estimation based on the spatial spectrum [1] is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. [2]. Using this method leads to a precise bearing estimation. The proposed method requires a relatively small amount of computation,...
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Miniaturized Passive Emission Chambers for In Situ Measurement of Emissions of Volatile Organic Compounds
PublicationThe results of many different studies have demonstrated unequivocally that the quality of indoor air is often much worse than that of atmospheric air. The presence of dangerous chemical compounds in indoor air can have an adverse impact on human health and cause numerous diseases of the respiratory and circulatory systems. Such harmful chemicals get into indoor air as a result of their emission from building and indoor materials....
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Expedited Optimization of Passive Microwave Devices Using Gradient Search and Principal Directions
PublicationOver the recent years, utilization of numerical optimization techniques has become ubiquitous in the design of high-frequency systems, including microwave passive components. The primary reason is that the circuits become increasingly complex to meet ever growing performance demands concerning their electrical performance, additional functionalities, as well as miniaturization. Nonetheless, as reliable evaluation of microwave device...
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Planning a Cost-Effective Delay-Constrained Passive Optical Network for 5G Fronthaul
PublicationWith the rapid growth in the telecommunications industry moving towards 5G and beyond (5GB) and the emergence of data-hungry and time-sensitive applications, Mobile Network Operators (MNOs) are faced with a considerable challenge to keep up with these new demands. Cloud radio access network (CRAN) has emerged as a cost-effective architecture that improves 5GB performance. The fronthaul segment of the CRAN necessitates a high-capacity...
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Performance of Passive and Active Balancing Systems of Lithium Batteries in Onerous Mine Environment
PublicationTo use lithium-iron-phosphate battery packs in the supply systems of any electric mining equipment and/or machines, the required conditions of work safety must be met. This applies in particular to coal mines endangered by fire and/or explosion. To meet the spark-safety conditions, the cells (together with the battery management system—BMS) must be isolated from the influence of the environment, and therefore placed in special...
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Measurements of passive components using of an IEEE 1149.4 mixed-signal test bus
PublicationW pracy przedstawiono wyniki badań nad wykorzystaniem magistrali testującej mieszanej sygnałowo IEEE 1149.4 do pomiarów elementów pasywnych zamontowanych na pakietach elektronicznych. Do badań użyto wyposażonych w magistralę układów scalonych typu STA400. Zaprezentowano metody pomiaru rezystancji pojedynczych elementów z wykorzystaniem źródła prądowego oraz źródła VH znajdującego się w analogowych modułach ABM układu STA400. Pokazano...
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Management Strategy for Seaports Aspiring to Green Logistical Goals of IMO: Technology and Policy Solutions
PublicationRecently, because of serious global challenges including the consumption of energy and climate change, there has been an increase in interest in the environmental effect of port operations and expansion. More interestingly, a strategic tendency in seaport advancement has been to manage the seaport system using a model which balances environmental volatility and economic development demands. An energy efficient management system...
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New Alternative Passive Networks to Improve the Range Output Voltage Regulation of the PWM Inverters
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Passive layer cracking studies performed on A95056 Aluminum Alloy by DEIS and acoustic emission
PublicationZbadano proces pękania warstwy pasywnej na stopie aluminium A95056 w warunkach zmiennych naprężeń rozciągających i polaryzacji anodowej z wykorzystaniem techniki DEIS oraz emisji akustycznej (AE), jako metody porównawczej. Określono elektrochemiczne i mechaniczne przyczyny badanego procesu. Wyznaczono progową (krytyczną) wartość naprężeń, przy których zarejestrowano proces pękania warstwy pasywnej na badanym stopie aluminium. Badanemu...
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Incorporation of nitrogen in diamond films - A new way of tuning parameters for optical passive elements
PublicationThis paper investigates the impact of nitrogen incorporation in diamond films for the construction of an interferometric sensor to measure displacement. Diamond films with different nitrogen levels (0–5%) were deposited on silicon substrates by microwave plasma enhanced chemical vapor deposition. The structural characteristics of these samples are characterized using scanning electron microscopy (SEM), atomic force microscopy...
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Method to determine the critical concentration Rayleigh number in isothermal passive membrane transport processes
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Application of galvanodynamic impedance spectroscopy for studying passive film cracking under mechanical strain
PublicationThe paper reports the results of simultaneous mechanical and electrochemical investigations on austenitic (18/8) stainless steel in a 2 % solution of sulphuric acid. The measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Electrochemical analysis of mechanical passive layer cracking and repassivation conditions during a tensile test was carried out. Application of this methodology allowed...
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Automatic localization and continous tracking of mobile sound source using passive acoustic radar
PublicationA concept, practical realization and applications of the passive acoustic radar for localization and continuous tracking of fixed and mobile sound sources such as: cars, trucks, aircrafts and sources of shooting, explosions were presented in the paper. The device consists of the new kind of multi-channel miniature three dimensional sound intensity sensors invented by the Microflown company and a group of digital signal processing...
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Cyclic analysis of thermal impedance of a passive layer of aluminium in a neutral borate buffer solution
PublicationW pracy przedstawiono wyniki badań warstwy pasywnej tworzącej się na stopie 1050 A w warunkach zmieniającej się temperatury. Zmiany realizowano w sposób cykliczny zwiększając a następnie zmniejszając temperaturę. W czasie zmian temperatury prowadzono badania metodę dynamicznej elektrochemicznej spektroskopii impedancyjnej. Stwierdzono największe zmiany parametrów elektrycznego schematu zastępczego w czasie pierwszego cyklu zmian....
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Passive Variable Fractional Delay Filter Design using Distributed Maximal Flatness Method
PublicationW pracy przedstawiono nową metodę projektowania pasywnych filtrów ułakowoopóźniających opartą na metodzie rozproszonej maksymalnej płaskości. W zaproponowane podejście jest uogólnieniem najbardziej popularnej metody projektowania filtrów maksymalnie płaskich - metody projektowania filtrów maksymalnie płaskich. Filtr maksymalnie płaski cechuje bardzo dobra jakość jedynie w wąskim paśmie wokół częstotliwości zerowej, ale jego istotną...
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The Dilemmas of Choosing a Suitable Technology for Low Energy and Passive Houses in the Context of their Overheating Issues
PublicationIn compliance with European Union directives, numerous countries are introducing increasingly stricter legal limits on the estimated energy consumption of newly designed residential buildings. However, the fact, that regulations and designers' efforts are focused on decreasing energy consumption (and consequently carbon dioxide emissions) only at the post-occupancy stage, may lead to a significant increase in the carbon footprint...
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Issues relating to the efficient Application of passive solar protection in multi-family residential buildings
PublicationThe following article is intended to discuss the issues concerning the introduction of passive measures aimed at improving solar protection in multi-family buildings. A system of classifying these methods into two groups of solutions (architectural and material-building) was applied. The first group includes issues concerning facade design, the spatial features of which (such as loggias, balconies and other overhangs) can be treated...
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Incorporation of nitrogen in diamond films – A new way of tuning parameters for optical passive elements
PublicationThis paper investigates the impact of nitrogen incorporation in diamond films for the construction of an interferometric sensor to measure displacement. Diamond films with different nitrogen levels (0–5%) were deposited on silicon substrates by microwave plasma enhanced chemical vapor deposition. The structural characteristics of these samples are characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), confocal...
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Control of the bridge span vibration with high coefficient passive damper. Theoretical consideration and application
PublicationThe research was carried out due to the problem of vibration on the lively pedestrian drawbridge across the Motlawa River in the city of Gdansk. In the design stage, the main span of the footbridge showed unfavorable dynamic properties, which may create a comfort problem for pedestrians. The first vertical bending eigenfrequency was recognized as 1.64 Hz. The original design of the footbridge was equipped with a driving cylinder...
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New Alternative Passive Networks to Improve the Range Output Voltage Regulation of the PWM Inverters
PublicationThis paper presents different topologies of buck-boost converters with passive input networks that have alternative topologies; this is known in the literature as a Z-source inverter. Alternative passive networks were named by the authors as T-inverters; these improve output voltage regulation of the PWM inverters. T-inverter has fewer reactive components in comparison to conventional Z-source inverter. The most significant advantage...
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Proof of Concept of Indoor Location System Using Long RFID Readers and Passive Tags
PublicationThe paper proposes a system for persons and objects location with the use of long radio-frequency identifications (RFIDs) readers. In order to investigate all aspects of the proposed location system, several key elements had to be analyzed, including the distance from which the tagged objects and the possibility of using more than one tag within one RFID range at the same time. When designing the system, it is also necessary to...
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The Influence of Microstructure on the Passive Layer Chemistry and Corrosion Resistance for Some Titanium-Based Alloys
PublicationThe effect of microstructure and chemistry on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys, was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys...
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Mobile Cloud computing architecture for massively parallelizablegeometric computation
PublicationCloud Computing is one of the most disruptive technologies of this century. This technology has been widely adopted in many areas of the society. In the field of manufacturing industry, it can be used to provide advantages in the execution of the complex geometric computation algorithms involved on CAD/CAM processes. The idea proposed in this research consists in outsourcing part of the load to be com- puted in the client machines...
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Mythologiai–Mythologemata: irredectubilidad del mito en la dramaturgia latinoamericana (Eestudio del teatro de León Febres-Cordero)
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Developing assumptions for the tram noise attenuation passive system using the noise maps analysis method
PublicationThe paper presents experimental research carried out to determine the possible actions to reduce thenoise generated by trams in a highly urbanised area. A few design strategies affecting tram ride qualityhave been presented – especially in the aspect of the acoustic phenomena. Main sources of the noisein trams were characterised. The paper includes selected results of comprehensive...
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Effect of housing geometry on the performance of Chemcatcher passive sampler for the monitoring of hydrophobic organic pollutants in water
PublicationZaprojektowano nową obudowę próbnika typu Chemcatcher, tzw. próbnik typu Chemcatcher drugiej generacji. Większość badań kalibracyjnych przeprowadzono stosując próbnik typu Chemcatcher pierwszej generacji. Dlatego zbadano wpływ obudowy próbnika typu Chemcatcher na jego działanie.
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Determination of Volatile Organic Compounds in Indoor Air in the Gdansk Area Using Permeation Passive Samplers
PublicationPassive dosimetry — known for over a hundred years — is still a useful tool in monitoring air pollutants. In this work, permeation passive samplers were used to determine indoor air quality in 22 apartments located in the Gdansk area in the northern part of Poland. The results obtained by the passive sampling technique were compared to those obtained by dynamic sampling. Attempts were also made to identify indoor sources of...
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Dynamic electrochemical impedance spectroscopy measurements of passive layer cracking under static tensile stresses
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Study of passive deck-flaps flutter control system on full bridge model. II: Results
PublicationZaprezentowano badania parametryczne systemu sterowania flatterem przy pomocy dołączonych stateczników na modelu wyprowadzonego w formalizmie metody elementów skończnych. Wyniki wskazują na efektywność systemu stosującego symetryczne sprzężenie ruchu stateczników z ruchem skrętnym mostu.
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Study of passive deck-flaps flutter control system on full bridge model. I: Theory
PublicationSformułowano modele matematyczne drgań mostu z zamontowanym pasywnym systemem sterowania flatterem w formalizmie metody elementów skończonych. System wykorzystuje stateczniki dołączone bezpośrednio do przęsła mostu. Siły aerodynamiczne działające bezpośrednio na most i stateczniki sformułowane są w przestrzeni czasu.
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Static renewal and continuous-flow calibration of two types of passive samplers for the monitoring of pharmaceuticals in wastewater
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Limitations of Integrative Passive Samplers as a Tool for the Quantification of Pharmaceuticals in the Environment – A Critical Review with the Latest Innovations
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Dynamic elektrochemical impedance spectroscopy measurements of passive layer cracking under static tensile stresses.
PublicationDynamiczna elektrochemiczna spektroskopia impedancyjna umożliwia badanie podatności i odporności korozyjnej różnych materiałów konstrukcyjnych, a w szczególności określenie właściwości elektrochemicznych warstw pasywnych występujących na ich powierzchni. W wielu przypadkach pęknięcie warstwy pasywnej pod wpływem działania naprężeń rozciągających prowadzi do korozji naprężeniowej. Z tego względu badania pękania warstw pasywnych...
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Dynamic electrochemical impedance spectroscopy measurements of passive layer cracking under static tensile stresses.
PublicationDynamiczna Elektrochemiczna Spektroskopia Impedancyjna umożliwia badanie podatności i odporności korozyjnej różnych materiałów konstrukcyjnych, a w szczególności określenie właściwości elektrochemicznych warstw pasywnych występujących na ich powierzchni. W wielu przypadkach pęknięcie warstwy pasywnej pod wpływem działania naprężeń rozciągających prowadzi do korozji naprężeniowej. Z tego względu badania pękania warstw pasywnych...
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Optimizing of target detection and tracking processes realized on consoles of passive sonar with linear towed antenna
PublicationThe long-range passive towed sonar was first modernised a few years ago. Building on operator experience over that period, a concept was developed of optimising the tasks performed by sonar operators, and improving forms of imaging to inform about object detection and support object tracking. The concept was implemented and successfully tested during ships’ manoeuvres. The optimisation of operator tasks was designed to keep listening...
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Application of passive sampling technique in monitoring research on quality of atmospheric air in the area of Tczew, Poland.
PublicationThis paper presents the results of atmospheric air quality research in Tczew (adjacent to the Vistula River) on the content of BTEX compounds. Analytical procedure applied during the sampling of the analytes from the air used the passive sampling technique (diffusive passive sampler, Radiello®). For determination of BTEX compounds in atmospheric air, two-stage thermal desorption technique combined with gas chromatography (TD-GC-FID)...
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The home-made in situ passive flux sampler for the measurement of monoterpene emission flux: preliminary studies
PublicationThe paper presents the construction and metrological characteristics of the home-made in situ passive flux sampler, an analytical tool representing small-scale emission chambers working in situ and passively sampling analytes from the gaseous phase. The sorption element was a cylindrical container made of stainless steel net, packed with a carbon sorbent bed-graphitized charcoal, Carbograph 4 (35/50mesh). The recommended working/exposure...
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A Multichannel Receiver of the Experimental FM Based Passive Radar Using Software Defined Radio Technology
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Determination of Volatile Organic Compounds in indoor air in the Gdansk area using permeation passive samplers.
PublicationDozymetria pasywna, znana od wielu lat, jest użytecznym narzędziem w monitoringu poziomu zanieczyszczeń. Do określenia jakości powietrza wewnętrznego w 22 pomieszczeniach mieszkalnych, zlakoalizowanych na terenie Gdańska, wykorzystano dozymetry pasywne typu permeacyjnego na etapie pobierania próbek analitów. Uzyskane wyniki porównano z wynikami uzyskanymi przy wykorzystaniu matedy dynamicznej. Podjęto również próbę identyfikacji...
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Comparing traffic intensity estimates employing passive acoustic radar and microwave Doppler radar sensor
PublicationThe purpose of our applied research project is to develop an autonomous road sign with built-in radar devices of our design. In this paper, we show that it is possible to calibrate the acoustic vector sensor so that it can be used to measure traffic volume and count the vehicles involved in the traffic through the analysis of the noise emitted by them. Signals obtained from a Doppler radar are used as a reference source. Although...
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Near-Field Wireless Sensing of Plastics and Papers Using Frugal Peel-Off Passive Tag
PublicationThis article presents a novel frugal approach of testing plastics and papers using a near-field microwave sensing technique with a peel-off tag. The proposed sensing technique involves two electrical entities: the sensor, which may be regarded as a reader, and a disposable tag. The reader is a modified design of a gap-coupled microstrip line (GCML) sensor, while the passive tag is a standard double-ring complementary split-ring...
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Estimating Traffic Intensity Employing Passive Acoustic Radar and Enhanced Microwave Doppler Radar Sensor
PublicationInnovative road signs that can autonomously display the speed limit in cases where the trac situation requires it are under development. The autonomous road sign contains many types of sensors, of which the subject of interest in this article is the Doppler sensor that we have improved and the constructed and calibrated acoustic probe. An algorithm for performing vehicle detection and tracking, as well as vehicle speed measurement,...
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The effectiveness of therapeutic massage in neck pain – prospective, preliminary studies
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Direct Constraint Control for EM-Based Miniaturization of Microwave Passives
PublicationHandling constraints imposed on physical dimensions of microwave circuits has become an important design consideration over the recent years. It is primarily fostered by the needs of emerging application areas such as 5G mobile communications, internet of things, or wearable/implantable devices. The size of conventional passive components is determined by the guided wavelength, and its reduction requires topological modifications,...
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Pounding mitigation of a short-span cable-stayed bridge using a new hybrid passive control system
PublicationThis paper investigates the effectiveness of a new hybrid passive control system on the seismic response of an existing steel cable-stayed bridge considering the pounding effect. The proposed hybrid passive control system comprises a seismic isolator and a metallic damper. The bridge is located in a high seismic zone and has suffered several damages including the earthquake-induced pounding damage during the 1988 earthquake....
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Employment of passive sampling in monitoring indoor air quality in selected residences in a Tri-city area in Poland
PublicationTime-weighted average concentrations of selected volatile compounds were measured in chosen residences in a Tri-City area of Poland by means of passive sampling. The results were compared to those obtained by dynamic technique – sorption tubes filled with Tenax TA sorbent. Results obtained by employing the two techniques were similar. Total volatile organic compound (TVOC) parameters were also determined. An attempt was also...
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Application of the chromatographic retention index system for the estimation of the calibration constants of permeation passive samplers with polydimethylsiloxane membranes
PublicationThe paper presents the results of research on the calibration of permeation passive samplers equipped with polydimethylsiloxane (PDMS) membranes using the physico-chemical properties of the analytes. Strong correlations were found between the calibration constants of the samplers and the linear temperature-programmed retention indices of the analytes determined on columns coated with pure PDMS (r2 = 0.914). These correlations...
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Employment of passive sampling in monitoring indoor air quality in selected residences in a Tri-city area in Poland
PublicationNa etapie pobierania próbek analitów zastosowano dwie techniki: pasywną - wykorzystującą permeacyjne dozymetry pasywne oraz technikę klasyczną - wykorzystującą rurki sorpcyjne. Wyznaczono sumaryczną zawartość TVOC lotnych związków organicznych.
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Application of the PASSIL technique for the passive sampling of exemplary polar contaminants (pharmaceuticals and phenolic derivatives) from water
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New possibilities of the passive layer cracking dynamics detection using a new Dynamic Electrochemical Impedance Spectroscopy.
PublicationNowa metoda Dynamicznej Elektrochemicznej Spektroskopii Impedancyjnej opracowana w Katedrze Elektrochemii, Korozji i Inżynierii Materiałowej Politechniki Gdańskiej daje możliwości określania charakterystyki impedancyjnej w dziedzinie czasu podczas procesu pękania ochronnej warstwy pasywnej. Fakt ten jest związany z procedurą analizującą wspomnianej techniki, która umożliwia selektywną analizę czasowo-częstotliwościową uzyskanych...