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Search results for: SAMPLING
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Adaptive Sampling for Non-intrusive Reduced Order Models Using Multi-Task Variance
PublicationNon-intrusive reduced order modeling methods (ROMs) have become increasingly popular for science and engineering applications such as predicting the field-based solutions for aerodynamic flows. A large sample size is, however, required to train the models for global accuracy. In this paper, a novel adaptive sampling strategy is introduced for these models that uses field-based uncertainty as a sampling metric. The strategy uses...
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublicationIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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Enhanced uniform data sampling for constrained data‐driven modeling of antenna input characteristics
PublicationData-driven surrogates are the most popular replacement models utilized in many fields of engineering and science, including design of microwave and antenna structures. The primary practical issue is a curse of dimensionality which limits the number of independent parameters that can be accounted for in the modelling process. Recently, a performance-driven modelling technique has been proposed where the constrained domain of the...
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Testing and sampling devices for monitoring volatile and semi-volatile organic compounds in indoor air
PublicationAdults spend most of their time in enclosed spaces (e.g., apartment, office and public buildings). According to research conducted by scientists, air quality indoors is much worse than the ambient air quality outdoors. Hazardous chemicals found in air indoors can adversely affect the functioning of the human body and cause many respiratory and circulatory diseases. Harmful chemical compounds (mainly volatile organic compounds and...
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Application of different sampling procedures in studies of composition of various types of runoff waters - a review
PublicationInformacje o metodyce pobierania próbek i położeniu stanowiska obserwacyjnego warunkują prawidłowy wynik analizy i możliwość porównania go z innymi danymi. W publikacji omówiono różne typy próbników stosowanych do pobierania próbek wód spływnych dostających się do środowiska w wyniku zmywania przez opady atmosferyczne zanieczyszczeń z takich powierzchni jak: arterie komunikacyjne, dachy budynków, obszary rolnicze i leśne oraz hałdy...
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Self-Testing of Analog Parts Terminated by ADCs Based on Multiple Sampling of Time Responses
PublicationA new approach for self-testing of analog parts terminated by analog-to-digital converters in mixed-signal electronic microsystems controlled by microcontrollers is presented. It is based upon a new fault diagnosis method using a transformation of the set of voltage samples of the time response of a tested analog part to a square impulse into localization curves placed in a multidimensional measurement space. The method can be used...
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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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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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Sampling-based novel heterogeneous multi-layer stacking ensemble method for telecom customer churn prediction
PublicationIn recent times, customer churn has become one of the most significant issues in business-oriented sectors with telecommunication being no exception. Maintaining current customers is particularly valuable due to the high degree of rivalry among telecommunication companies and the costs of acquiring new ones. The early prediction of churned customers may help telecommunication companies to identify the causes of churn and design...
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Pobieranie próbek opadów i osadów atmosferycznych do analizy. Sampling of atmospheric precipitation and deposits for the analysis.
PublicationOmówiono różne typy próbników stosowanych do pobierania próbek opadów i osadów atmosferycznych (mgła i woda z chmur, rosa i szadź). Zaprezentowano urządzenia o różnym stopniu automatyzacji. Przedstawiono również informacje literaturowe na temat oznaczania związków nieorganicznych i organicznych w próbkach opadów i osadów atmosferycznych z zastosowaniem odpowiednich technik pomiarowych.
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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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Self-testing of analog parts of mixed-signal electronic microsystems based on multiple sampling of time responses
PublicationW artykule przedstawiono nowe podejście samo-testowania toru analogowego zakończonego przetwornikiem A/C w mieszanych sygnałowo elektronicznych systemach wbudowanych sterowanych mikrokontrolerami. Bazuje ono na nowej metodzie diagnostycznej opartej na przekształceniu transformującym zbiór próbek odpowiedzi czasowej układu badanego na pobudzenie impulsem prostokątnym na rodzinę krzywych identyfikacyjnych umieszczonych w przestrzeni...
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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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Accuracy improvement of the prestressed concrete structures precise geometry assessment by use of bubble micro-sampling algorithm
PublicationPrestressed concrete structures are well-known technology for a vast period, but nevertheless, this very technology is a leading solution, currently used in construction industry. Prestressed concrete structures have a huge advantage over conventional methods because it uses the properties of concrete in a very efficient way. The main idea behind this technology is to introduce into the cross-section of the structure, the internal...
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Preliminary study on suitability of ionic liquids as potential passive-sampling media of polyaromatic-hydrocarbon (PAH) analyses in water
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Error analysis of calculating average d-q current components using Regular Sampling and Park transformation in FOC drives
PublicationIn electric drives using voltage source inverters, motor currents contain ripple component resulting from pulse-width modulated (PWM) voltage. The frequency range of the ripples is much higher than the bandwidth of current control. Therefore the control is performed on the basis of a fundamental current component, i.e. average value with the averaging time being the PWM period. In majority of cases the average current is measured...
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Application of passive sampling technique for monitoring of BTEX concentration in urban air: Field comparison of different types of passive samplers
PublicationW efekcie przeprowadzonych badań potwierdzono przydatności techniki dozymetrii pasywnej wykorzystywanej na etapie izolacji i wzbogacania analitów do uzyskania informacji o poziomie stężeń zanieczyszczeń z grupy BTEX w powietrzu atmosferycznym na terenie aglomeracji Trójmiejskiej. Dodatkowo, porównano wyniki oznaczeń uzyskanych z wykorzystaniem dwóch typów dozymetrów pasywnych.
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Unconventional and user-friendly sampling techniques of semi-volatile organic compounds present in an indoor environment: An approach to human exposure assessment
PublicationThe commonly applied solutions used to assess the potential risk of human exposure to semi-volatile organic compounds (SVOCs) are based on the investigation of biological samples collected in an invasive or non-invasive manner. For SVOCs, which are typically introduced to humans through the respiratory system, dermal adsorption, or digestive system, sampling solutions generally used in the indoor environments are classified as...
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Pobieranie próbek opadów atmosferycznych do analizy. Opis stosowanych próbników. Sampling of atmospheric precipitation for the analysis. Description applied samplers
PublicationW pracy przedstawiono opis podstawowych typów próbników wykorzystywanych do pobierania próbek opadów atmosferycznych (woda deszczowa, wody spływne, mgła) oraz tok postępowania analitycznego z pobranymi próbkami w celu oznaczenia szerokiego spektrum składników śladowych.
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Weighted Ensemble with one-class Classification and Over-sampling and Instance selection (WECOI): An approach for learning from imbalanced data streams
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Diagnostics of the tram track shape with the use of the global positioning satellite systems (GPS/Glonass) measurements with a 20 Hz frequency sampling
PublicationSatellite geodetic measurements used in the diagnosis of railway tracks require professional receivers and a very high frequency rate of data processing. It stems from a significant speed (10 km/h) kinematic measurements carried out during the passage of a measuring platform. The survey results (positions) of deformed railroad track have waveforms nature requiring additional processing methods and approximations. Due to the announcement...
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Zastosowanie techniki dozymetrii pasywnej do oceny jakości powietrza wewnętrznego. Application of passive sampling technique for assessment of indoor air quality
PublicationJakość powietrza wewnętrznego jest istotnym parametrem wpływającym na dobre samopoczucie i zdrowie człowieka. Kluczowego znaczenia nabiera więc jego nieustanna kontrola i oznaczanie zawartości zanieczyszczeń, które występują w nim na bardzo niskich poziomach stężeń. Do pomiarów jakości powietrza wewnętrznego często wykorzystywana jest (znana od ponad pół wieku) technika dozymetrii pasywnej. W literaturze nadal pojawiają się doniesienia...
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Membrane in tandem with a helical sorbent trap as continuous sampling technique of the polyvinyl chloride thermo-oxidative degradation products for their on-line gas chromatographic monitoring
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Próbki wód spływnych - sposób pobierania z różnych powierzchni i ich skład chemiczny = Samples of runoff water - sampling procedures for different surfaces and chemical composition
PublicationPrzedstawiono dane dotyczące chemizmu wód spływnych dostających się do środowiska w wyniku zmywania przez opady atmosferyczne zanieczyszczeń z takich powierzchni jak: arterie komunikacyjne, dachy budynków, obszary rolnicze i leśne oraz hałdy odpadów. Wyniki uzyskane w trakcie badań własnych zestawiono z danymi literaturowymi. Informacje o metodyce pobierania próbek i położeniu stanowiska obserwacyjnego warunkują prawidłowy wynik...
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Passive sampling techniques in monitoring of BTEX in urban air = Technika dozymetrii pasywnej w monitoringu analitów z grupy BTEX w powietrzu atmosferycznym na obszarach miejskich
PublicationLotna związki organiczne, a wśród nich związki z grupy BTEX, odgrywają istotną rolę w chemii środowiska. Mogą one oddziaływać znacząco na abiotyczną jak i biotyczną część środowiska. Nie bez znaczenia jest również wpływ LZO na organizmy żywe w tym na zdrowie ludzkie. Ponadto posiadają one zdolność do kumulowania się w organizmach żywych zwiększając ryzyko zachorowań. Niektóre z nich mogą również niekorzystnie oddziaływać na organizmy...
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Passive sampling techniques in monitoring of BTEX in urban air = Technika dozymetrii pasywnej w monitoringu analitów z grupy BTEX w powietrzu atmosferycznym na obszarach miejskich
PublicationLotna związki organiczne, a wśród nich związki z grupy BTEX, odgrywają istotną rolę w chemii środowiska. Mogą one oddziaływać znacząco na abiotyczną jak i biotyczną część środowiska. Nie bez znaczenia jest również wpływ LZO na organizmy żywe w tym na zdrowie ludzkie. Ponadto posiadają one zdolność do kumulowania się w organizmach żywych zwiększając ryzyko zachorowań. Niektóre z nich mogą również niekorzystnie oddziaływać na organizmy...
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What should we know when choosing feather, blood, egg or preen oil as biological samples for contaminants detection? A non-lethal approach to bird sampling for PCBs, OCPs, PBDEs and PFASs
PublicationBirds are considered as good bio-monitors and they can provide highly valuable data about the level of contamination in their habitat. During the design of biomonitoring studies one of the first issues after choosing species is the choice of biological material. Non-lethally collected samples have recently been gaining greater attention as they offer several ethical and practical advantages. However, not all sample matrices are...
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Monitorowanie i mapowanie zanieczyszczenia powietrza atmosferycznego przez związki z grupy BTEX (benzen, toluen, etylobenzen, ksylen) z wykorzystaniem techniki dozymetrii pasywnej do pobierania próbek analitów = Monitoring and mapping of atmospheric pollutans with the use of passive technique of sampling of BTEX (benzene, ethylbenzene, toluene, xylenes) analytes
PublicationWskutek działalności człowieka do atmosfery dostaje się coraz większa liczba substancji szkodliwych, uznanych za potencjalnie niebezpieczne dla organizmów żywych, głównie z uwagi na ich toksyczność. Do takich substancji zalicza się między innymi związki z grupy BTEX. Chcąc ocenić stopień narażenia populacji na obecność w powietrzu atmosferycznym analitów z grupy BTEX, niezbędne jest monitorowanie poziomu stężeń tych zanieczyszczeń...
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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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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part II. Sample collection and preparation
PublicationThe paper reviews literature information on air sampling techniques commonly used for monitoring volatile organic compounds (VOCs) levels in atmospheric air. It describes containers for collecting samples of atmospheric air, such as vacuum canisters and bags made from synthetic materials. It discusses dynamic, passive and denudational techniques for sampling analytes from air combining isolation with preliminary enrichment, and...
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Badanie wierności brzmienia dźwięku instrumentów wirtualnych VST/TRTAS
PublicationTematem referatu jest subiektywne badanie wierności brzmienia instrumentów wirtualnych (VST/TRTAS) wykorzystujących próbkowanie dźwięków rzeczywistych instrumentów muzycznych. Na potrzeby przedstawionej pracy wybrano kilka utworów muzyki orkiestrowej z epoki romantyzmu i klasycyzmu, nagranych przy użyciu instrumentów akustycznych. Następnie zaaranżowano fragmenty tych utworów, wykorzystując do tego instrumenty wirtualne i efekty...
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Analiza wpływu błędu częstotliwości próbkowania na sygnały odbierane w systemie LTE
PublicationW artykule dokonano analizy wpływu błędu częstotliwości próbkowania w platformie radia programowalnego na odbierany sygnał LTE (Long Term Evolution).
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The Application of a Mobile Unmanned Device for Monitoring Water and Sediment Pollution in the Port of Gdynia
PublicationPollution in the Port of Gdynia can encompass various types of substances and contaminants that affect the quality of water and sediment in this region. Ships entering and leaving the port can release pollutants such as oil, fuel, waste, and chemicals into the water. Controlling and monitoring these pollutants is a crucial part of environmental stewardship. In recent years, uncrewed units have been increasingly in use for in situ...
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Sample preparation and recent trends in volatolomics for diagnosing gastrointestinal diseases
PublicationThe analysis of the human volatilome can be successfully used for rapid and non-invasive diagnostics of gastrointestinal diseases. However, the introduction of techniques based on detection of volatiles is limited, among other factors, by difficulties which arise during the sampling stage and instrumental analysis. The aim of this article was to review and discuss medical and analytical literature on the analysis of volatiles in...
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Green Sample Collection
PublicationThe term of “green sample collection” is directly associated with both passive and dynamic analytical tools which allow for simultaneous management of the stage of collection and isolation and/or enrichment of a broad spectrum of chemical compounds from environmental samples. The use of passive sampling techniques at the stage of sample collection makes it possible to obtain in a simple yet inexpensive manner an analytical information...
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites
PublicationThe baby disposable diapers were investigated as a sampling material for urine collection and validated for the evaluation of the exposure of children to xenobiotics. Phthalate metabolites detected in urine samples were chosen as proof-of-concept analytes. For the determination of phthalate metabolites in children’s urine samples, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used. Two...
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Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
PublicationObjective. The aim of the study is to investigate the effect of the signal sampling frequency and low-pass filtering on the accuracy of the localisation of the fiducial points of the photoplethysmographic signal (PPG), and thus on the estimation of the blood pressure (i.e. the accuracy of the estimation). Approach. Statistical analysis was performed on 3,799 data samples taken from a publicly available database. Four PPGfiducial...
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Flexible Knowledge–Vision–Integration Platform for Personal Protective Equipment Detection and Classification Using Hierarchical Convolutional Neural Networks and Active Leaning
PublicationThis work is part of an effort to develop of a Knowledge-Vision Integration Platform for Hazard Control (KVIP-HC) in industrial workplaces, adaptable to a wide range of industrial environments. The paper focuses on hazards resulted from the non-use of personal protective equipment (PPE). The objective is to test the capability of the platform to adapt to different industrial environments by simulating the process of randomly selecting...
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Effectiveness of Random Field Approach in Serviceability Limit State Analysis of Strip Foundation
PublicationThis work conducts a probabilistic inquiry on how the variability of the parameter defining soil deformability affects the settlement of the foundation located on the soil. The analysis addresses the random foundation model to relevantly estimate the probability of allowable deflection exceedance. The constitutive model parameter is based either on a single random variable or a random field. The computations incorporate direct...
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublicationThis paper describes a sensorless Interior Permanent Magnet Synchronous Motor (IPMSM) drive designed for traction applications. Wide-speed sensorless operation is provided with the use of three methods of rotor position estimation designed for: a standstill, low- and high-speed range. The paper focuses on the high-speed estimation algorithm. The estimator uses the derivatives of motor phase currentsresulting from PWM modulation...
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Digital Processing of Frequency–Pulse Signal in Measurement System
PublicationThe work presents the issue of the use of multichannel measurement systems of sensors processing input value to impulse signal frequency. The frequency impulse signal obtained from such sensors is often required to be processed at the same time with a voltage signal which is obtained from other sensors used in the same measurement system. In such case, it is usually necessary to sample the output signals from all sensors in the...
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In-ADC, Rank-Order Filter for Digital Pixel Sensors
PublicationThis paper presents a new implementation of the rank-order filter, which is established on a parallel-operated array of single-slope (SS) analog-to-digital converters (ADCs). The SS ADCs use an “on-the-ramp processing” technique, i.e., filtration is performed along with analog-to-digital conversion, so the final states of the converters represent a filtered image. A proof-of-concept 64 × 64 array of SS ADCs, integrated with MOS...
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Analytical modeling of electric drives for vehicle traction control systems
PublicationWheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five...
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Particulate Material Analysis in Air
PublicationThe chapter presents the methods and techniques used to asses the PM10 in air and different instruments typically used in analysis of PM, including sampling of particle by using filters and other systems. Besides the methods recommended by different national standards the other methods, especially electronic microscopy are also described.
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BEXUS 30 Stardust – Preliminary Results of Investigation of Microbes in the Stratosphere
PublicationThe stratospheric microbiome has been investigated several times using the methods of classical microbiology. In this experiment, we have combined them with some novel approaches.. Diversification of methods has helped better describe the collected microorganisms. The results of the experiment may help better understand the mechanisms of survivability of microorganisms in stratospheric conditions.
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Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
PublicationPulse width modulation (PWM) of inverter output voltage causes the waveforms of motor phase cur-rents to consist of distinctive ripples. In order to provide suitable feedback for the motor current con-trollers, the mean value must be extracted from the currents’ waveforms in every PWM cycle. A com-mon solution to derive the mean phase currents is to sample their value at the midpoint of a symmetrical PWM cycle. Using an assumption...
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Online Volatile Compound Emissions Analysis Using a Microchamber/Thermal Extractor Coupled to Proton Transfer Reaction-Mass Spectrometry
PublicationIndoor air is a complex and dynamic mixture comprising manifold volatile organic compounds (VOCs) that may cause physiological and/or psychological discomfort, depending on the nature of exposure. This technical note presents a novel approach to analyze VOC emissions by coupling a microchamber/thermal extractor (μ-CTE) system to a proton transfer reaction-mass spectrometer (PTR-MS). This configuration provides an alternative to...
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Ellipse-fitting algorithm implementation in the impedance measurement system based on DAQ card with FPGA
PublicationThe paper presents an implementation of the ellipse-fitting algorithm in the impedance measurement system based on DAQ card equipped with FPGA chip. The method implementation was tested by simulation means as well as experimentally in the designed and presented measurement system. Finally, the limit values of sampling parameters which assures satisfying accuracy were given.
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Waveform design for fast clutter cancellation in noise radars
PublicationCanceling clutter is an important, but computation-ally intensive part of signal processing in noise radars. It is shown that considerable improvements can be made to a simple least squares canceler if minor constraints are imposed onto noise waveform. The proposed scheme is potentially capable of canceling clutter in real-time, even for high sampling rates.