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Wyniki wyszukiwania dla: CURRENT SAMPLING
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Error analysis of calculating average d-q current components using Regular Sampling and Park transformation in FOC drives
PublikacjaIn 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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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublikacjaMotor 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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Passive sampling and/or extraction techniques in environmental analysis: a review
PublikacjaThe current state-of-the-art of passive sampling and/or extraction methods for long-term monitoring of pollutants in different environmental compartments is discussed in this review. Passive dosimeters that have been successfully used to monitor organic and inorganic contaminants in air, water, sediments, and soil are presented. The application of new approaches to the determination of pollutants at the sampling stage is discussed....
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Using A Particular Sampling Method for Impedance Measurement
PublikacjaThe paper presents an impedance measurement method using a particular sampling method which is an alternative to DFT calculation. The method uses a sine excitation signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance is calculated without using Fourier transform. The method was first evaluated in MATLAB by means of simulation. The method was...
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Sensorless IPMSM drive with rotor position estimator based on analysis of phase current derivatives
PublikacjaThis 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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Errors of a Linear Current Approximation in High-Speed PMSM Drives
PublikacjaCurrent sampling techniques and predictive algorithms used in the digital control of electric drives rely on a simple mathematical model that assumes linear current changes upon constant supplying voltages. This paper identifies rotor movement as a factor that makes this assumption invalid when the rotor covers an angular distance of a few tens of degrees during the control interval duration. The errors of the linear current approximation...
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Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
PublikacjaPulse 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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Stability Analysis of Shunt Active Power Filter with Predictive Closed-Loop Control of Supply Current
PublikacjaThis paper presents a shunt active power filter connected to the grid via an LCL coupling circuit with implemented closed‐loop control. The proposed control system allows selective harmonic currents compensation up to the 50th harmonic with the utilization of a model‐based predictive current controller. As the system is fully predictive, it provides high effectiveness of the harmonic reduction, which is proved by waveforms achieved...
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Impact of digital signal processing on FOC current feedback in high-speed PMSM drive
PublikacjaIn applications where size and weight of the electric motor are among major design concerns, Permanent Magnet Synchronous Motors (PMSMs) with wide operational speed-range are commonly preferred. Due to limited inverter switching frequency, high-speed operation of a drive results in a low ratio between the switching frequency and the fundamental frequency of motor voltage. Such operating conditions have been recently identified...
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Current trends in solid-phase microextraction (SPME) fibre catings
PublikacjaThis critical review presents information on known and innovative approaches to the manufacture of fibre coatings used in solid-phase microextraction (SPME). The properties, advantages and drawbacks of the different types of commercially available SPME fibre coatings are discussed in detail, as are those of novel types of coatings and the methodologies of their preparation. The applications of fibre coatings in the solid-phase...
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Direct algorithm for optimizing robust MPC of drinking water distribution systems hydraulics
PublikacjaModel-based predictive control is an effective method for control the large scale systems [1]–[6], [8], [16], [17]. Method is based on on-line solution of the control task over the control horizon using current and past measurements, as well as the system model. Only a first element of calculated control sequence is applied to the plant. At the next sampling instant, based on new process output measurements, control procedure is...
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Analytical modeling of electric drives for vehicle traction control systems
PublikacjaWheel-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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Principles and Developments of Solid-Phase Microextraction
PublikacjaSample preparation has been commonly considered a critical step of the analytical process. In this sense, remarkable efforts have been made to develop efficient sample preparation techniques which could overcome the limitations of conventional approaches. Since its inception in the early 1990’s, solid-phase microextraction (SPME) has become a widespread miniaturized sample preparation technique for extraction and preconcentration...
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AUTOMATED SYSTEM FOR FLUCTUATION ENHANCED GAS SENSING
PublikacjaResistance gas sensors exhibit random phenomena (resistance noise) which can be utilized to improve gas sensitivity and selectivity. That new emerging technique has to be investigated to recognize optimal parameters for gas detection. It means that a measurement system has to have ability of numerous parameters adjustment (e.g., sampling frequency, heater voltage, polarization current, voltage noise amplification). That fact induced...
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Local variability in snow concentrations of chlorinated persistent organic pollutants as a source of large uncertainty in interpreting spatial patterns at all scales
PublikacjaSingle point sampling, a widespread practice in snow studies in remote areas, due to logistical constraints, can present an unquantified error to the final study results. The low concentrations of studied chemicals, such as chlorinated persistent organic pollutants, contribute to the uncertainty. We conducted a field experiment in the Arctic to estimate the error stemming from differences in the composition of snow at short distances...
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Fast High-Impedance Spectroscopy Method Using SINC Signal Excitation
PublikacjaIn this paper the method of fast impedance spectroscopy of technical objects with high impedance (|Zx| > 1 Gohm) is evaluated by means of simulation and practical experiment. The method is based on excitation of an object with a sinc signal and sampling response signals proportional to current flowing through and voltage across the measured impedance. The object impedance spectrum is obtained with use of continuous Fourier transform...
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Computational techniques for efficient conformational sampling of proteins
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Unlocking the Secrets of River Pollution: Analyzing Organic Pollutants in Sediments—Experimental Study
PublikacjaUntreated wastewater released into rivers can result in water pollution, the spread of waterborne diseases, harm to ecosystems, contamination of soil and groundwater, as well as air pollution and respiratory problems for nearby humans and animals due to the release of greenhouse gases. The current study aims to investigate the recent input of anthropogenic loads into the rivers using linear alkylbenzene (LAB), which is one of the...
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Impacts on human health in the Arctic owing to climate-induced changes in contaminant cycling – The EU ArcRisk project policy outcome
PublikacjaResults of the EU ArcRisk project on human health impacts in the Arctic owing to climate-induced changes in contaminant cycling are summarized in the context of their policy application. The question on how will climate change affect the transport of selected persistent organic pollutants (POPs) and mercury, both to and within the Arctic has been addressed, as well as the issue of human health impacts of these pollutants in the...
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HILS for the Design of Three-Wheeled Mobile Platform Motion Surveillance System with a Use of Energy Performance Index
PublikacjaCurrent tendency in mechatronic design requires the use of comprehensive development of an environment, which gives the possibility to prototype, design, simulate and integrate with dedicated hardware. The paper discusses the Hardware-In-the-Loop Simulations (HILS) mechatronic technique, used during the design of the surveillance system based on energy performance index. The presented test configuration (physical controller – emulated...
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Down-Sampling of Large LiDAR Dataset in the Context of Off-Road Objects Extraction
PublikacjaNowadays, LiDAR (Light Detection and Ranging) is used in many fields, such as transportation. Thanks to the recent technological improvements, the current generation of LiDAR mapping instruments available on the market allows to acquire up to millions of three-dimensional (3D) points per second. On the one hand, such improvements allowed the development of LiDAR-based systems with increased productivity, enabling the quick acquisition...
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Dominant Pathways of Adenosyl Radical-Induced DNA Damage Revealed by QM/MM Metadynamics
PublikacjaBrominated nucleobases sensitize double stranded DNA to hydrated electrons, one of the dominant genotoxic species produced in hypoxic cancer cells during radiotherapy. Such radiosensitizers can therefore be administered locally to enhance treatment efficiency within the solid tumor while protecting the neighboring tissue. When a solvated electron attaches to 8-bromoadenosine, a potential sensitizer, the dissociation of bromide...
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Sampling Strategies: Statistics of Sampling
PublikacjaEach step of the analytical procedure has a significant influence on the final result of the analysis. In the majority of cases the analytical procedure encompasses sampling because the analysis of the entire object (material) is usually not possible. Thus it is necessary to include the uncertainty related to sampling procedure in the uncertainty budget calculations. In the paper: the most important properties of the analysed...
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The Application of a Mobile Unmanned Device for Monitoring Water and Sediment Pollution in the Port of Gdynia
PublikacjaPollution 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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Validation of atmospheric aerosols sampling in equivalent fractions
PublikacjaPhysical properties and chemical composition of atmospheric aerosols are of extreme importance, in many fields of interest, namely the Environment even with legal implications. Atmospheric sampling poses inherent problems with consequent demands on sampling optimisation, with sampling strategies requiring validation. In this work a study was conducted aiming at validating the collection of atmospheric aerosols in equivalent fractions....
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Validation of a sampling procedure
PublikacjaEach step of the analytical procedure influences the final results in a significant way. In the majority of cases the analytical procedure encompasses sampling because the analysis of the entire object (material) is usually not possible. Thus it is necessary to include the uncertainty related to sampling procedure in the uncertainty budget calculations. This paper describes two basic ways of estimating the sampling uncertainty,...
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Sample preparation and recent trends in volatolomics for diagnosing gastrointestinal diseases
PublikacjaThe 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
PublikacjaThe 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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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublikacjaIn 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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Sampling Procedures in Studies of Cloud Water Composition: A Review
PublikacjaThe authors set out and classify the principles of operation of known types of cloud water collectors, and critically review their advantages and drawbacks. Analysis of the literature has yielded information on the parameters of various type of collectors—sampling time, the type of cloud from which the water sample was taken, droplet diameter collected with 50% efficiency (cut off), sample analytes/ parameters determined, types...
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Effects of Addictive Substances During Pregnancy and Infancy and Their Analysis in Biological Materials
PublikacjaThe use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency it detracts from childcare and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent...
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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
PublikacjaThe 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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Determination of Volatile Organic Compounds in Indoor Air in the Gdansk Area Using Permeation Passive Samplers
PublikacjaPassive 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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Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites
PublikacjaThe 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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Validation of atmospheric aerosols parallel sampling in a multifold device
PublikacjaIn this work, particulate matter was collected using an active sampling system consisting of a PM10 (<10 μm) inlet coupled to a multifold device containing six channels, connected to a vacuum pump. Each channel was equipped with a filter holder fitted with adequately chosen filters. The system was fixed on a metallic structure, which was placed on the roof of the laboratory building, at the Faculty of Sciences, in Lisbon. Sampling...
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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublikacjaData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part II. Sample collection and preparation
PublikacjaThe 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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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
PublikacjaBirds 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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Application of passive sampling techniques as a usable tool in the field of environmental quality monitoring
PublikacjaAnalysis of literature data published for the past 20 years leads to the conclusion, that passive sampling technique has been developing very quickly and is commonly used in the field of monitoring pollutants in air, water and soil environment. The popularity of application of passive sampling techniques in analytical and environmental chemistry results from its many advantages e.g.: Simplicity in use, low costs of exploitation,...
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Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
PublikacjaObjective. 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
PublikacjaThis 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
PublikacjaThis 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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In-ADC, Rank-Order Filter for Digital Pixel Sensors
PublikacjaThis 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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Digital Processing of Frequency–Pulse Signal in Measurement System
PublikacjaThe 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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Particulate Material Analysis in Air
PublikacjaThe 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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Online Volatile Compound Emissions Analysis Using a Microchamber/Thermal Extractor Coupled to Proton Transfer Reaction-Mass Spectrometry
PublikacjaIndoor 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
PublikacjaThe 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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Application of passive sampling technique in monitoring research on quality of atmospheric air in the area of Tczew, Poland.
PublikacjaThis 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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Waveform design for fast clutter cancellation in noise radars
PublikacjaCanceling 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.
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Analytical Techniques Used in Monitoring of Atmospheric Air Pollutants
PublikacjaThe air pollution monitoring is one of the most pressing environmental problems today. The paper describes common air pollutants, their interaction and impact on the environment, and classifies the techniques and methods applied in air studies. Furthermore, the review characterizes the selected collection and sampling techniques used for gas sample analysis. Finally, the schematic diagrams of typical designs of systems applied...