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Relations between magnetosonic perturbations as an indicator of a magnetosonic exciter and equilibrium parameters of a plasma
PublikacjaThe thermodynamic relations between perturbation of pressure and pertur- bation of mass density and between components of velocity which specify a magnetosonic wave are theoretically studied. A planar flow with the wave vec- tor forming a constant angle with the equilibrium magnetic field is investigated. The theory considers deviation from the adiabaticity of a flow due to some kind of heating–cooling function and thermal conduction...
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublikacjaA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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Audio-visual surveillance system for application in bank operating room
PublikacjaAn audio-visual surveillance system able to detect, classify and to localize acoustic events in a bank operating room is presented. Algorithms for detection and classification of abnormal acoustic events, such as screams or gunshots are introduced. Two types of detectors are employed to detect impulsive sounds and vocal activity. A Support Vector Machine (SVM) classifier is used to discern between the different classes of acoustic...
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Processing of acoustical data in a multimodal bank operating room surveillance system
PublikacjaAn automatic surveillance system capable of detecting, classifying and localizing acoustic events in a bank operating room is presented. Algorithms for detection and classification of abnormal acoustic events, such as screams or gunshots are introduced. Two types of detectors are employed to detect impulsive sounds and vocal activity. A Support Vector Machine (SVM) classifier is used to discern between the different classes of...
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Automatic sound source localization in disturbing conditions using acoustic vector sensors
PublikacjaA concept, practical realization and applications of a passive acoustic radar to automatic localization and tracking of sound sources in disturbing conditions were presented in the paper. The device consists of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. The sensitivity of the realized acoustic radar was examined in free sound field. Several kinds of sound...
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The moonuments of gdynia post-war construction pace
PublikacjaThe impresive pace of building objects realisation in the 1950s and 1960s was a continuation of the traditional gdynia building pace of the pre-war period. A particular attention and admiration must the reserved for the use at almost every construction site in Gdynia of a considerable quantify of prototypical meterial/construction solutions implemented above all in order to simplify technology and accelerate the pace of building...
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A tool for designing water tanks for measuring hydroacoustic transducers
PublikacjaSpecial water tanks are commonly used to measure the parameters of underwater acoustic systems. They must meet specific requirements, the fulfilment of which ensures very small but acceptable measurement errors. These requirements define the size of the tank and its shape as well as the strong attenuation of reflected waves. At the design stage, it is necessary to determine the impact of the tank structure on the measurement errors...
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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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Ruchotwórczość wielkopowierzchniowych obiektów handlowych trzeciej generacji na przykładzie Trójmiasta
PublikacjaWielkopowierzchniowe obiekty (handlowe, usługowe itp.) generują ruch o dużych natężeniach, które często przekraczają możliwości przepustowe przyległego układu ulicznego. Wpływają w ten sposób na znaczne pogorszenie się warunków ruchu w najbliższym otoczeniu obiektu i zakłócenia w prawidłowym funkcjonowaniu systemu transportowego miasta. Wobec braku polskich doświadczeń konieczne jest badanie wpływu wybranych czynników demograficznych,...
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Magdalena Brzozowska-Woś dr hab. inż.
OsobyMagdalena Brzozowska-Woś jest absolwentką Wydziału Zarządzania i Ekonomii Politechniki Gdańskiej (specjalność: systemy zarządzania). Jest również absolwentką Podyplomowego Studium Reklamy (Wydział Zarządzania i Ekonomii PG) oraz Podyplomowego Studium Public Relations (SWPS Uniwersytet Humanistycznospołeczny). W latach 2000-2003 współpracowała z Panoramą Internetu sp. z o. o. jako specjalista ds. marketingu. Pełniła również obowiązki...
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Formation enthalpies of LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) interlanthanide perovskites
PublikacjaHigh-temperature oxide melt solution calorimetry using 3Na2O·MoO3 at 802 °C was performed for interlanthanide perovskites LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) and lanthanide oxides (La2O3, Ho2O3, Er2O3, Tm2O3 and Yb2O3). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO3, −9.9±3.0 kJ/mol for LaErO3, −10.8±2.7 kJ/mol...
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Influence of Antimony Substitution on Spontaneous Strain and Thermodynamic Stability of Lanthanum Orthoniobate
PublikacjaThe analysis of the antimony substitution influence on temperature dependence of unit cell distortion has been done. The values of spontaneous strain and Landau order parameter for three different antimony contents varied had been calculated. The phase transition occurring for antimony substituted lanthanum orthoniobate was found to be second order. The high temperature solution calorimetry method has been used to investigate...
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Stabilization of the pyrochlore phase of Mn2Sb2O7 by double substitution
PublikacjaPolycrystalline samples of (Ce4+Mn2+3)(Ga3+Sb5+3)O14 were synthesized by a high-temperature solid-state reaction. In contrast with the parent Mn2Sb2O7 compound that adopts a rhombohedral or monoclinic structure at T > 600 °C, the pyrochlore structure of CeMn3GaSb3O14 is retained up to at least T = 1070°C. High-resolution synchrotron x-ray diffraction measurements show no sign of a superstructure or distortion from cubic symmetry...
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Curve Curvature Analysis of a Grain Trajectories in Variable Honing of Cylindrical Holes of Thin Wall Cylinder Liners as a Honing Process Optimization Strategy
PublikacjaThe main problem of honing of thin wall cylinder liners is a thermal distortion of honed holes. The higher the value of the temperature of the honed workpiece, the greater its holes deformation. The paper presents a method of reducing the temperature occurring in the honing process as a result of the application of a variable honing kinematics conditions with particular emphasis on the analysis of the effect of the value of the...
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Radar technique in application of interlayer identification connections
PublikacjaOne of important issues in pavement construction is to ensure that layers applied directly one on top of the other make up a continuous whole and form an integral construction complex. An appropriate interlayer connection plays here significant role ensuring proper transmission of distortions generated by wheels of vehicles to lower layers and preventing water penetration between the layers. In case of damaged pavements where lack...
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СИЛОВОЙ ПРЕОБРАЗОВАТЕЛЬ С АКТИВНЫМ ПОДАВЛЕНИЕМ ВЫСШИХ ГАРМОНИК ДЛЯ СИСТЕМ ЭЛЕКТРОСНАБЖЕНИЯ ЛЕТАТЕЛЬНЫХ АППАРАТОВ (Power converter with active suppression of higher harmonics for aircraft power supply systems)
PublikacjaПредставлены два алгоритма активной фильтрации для силового преобразователя с активным подавлением высших гармоник. Первый алгоритм основан на дискретном преобразовании Фурье: посредством синтезированной системы управления инвертированные измеренные высшие гармоники напряжения поступают на вход инвертора. Второй метод управления основан на алгоритме с использованием принципов самообучения, что значительно снижает потребность в...
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The interplay between Disinhibition and Present-Hedonistic time perspective in the relation between Borderline Personality Organization and depressive symptoms
PublikacjaThe purpose of the current study was to examine the moderating effect between borderline personality organization (BPO) and depressive symptoms of factors associated with impulsive behavior – Present-Hedonistic time perspective and Disinhibition. The research sample consisted of 720 adults from Poland (518 females), who participated in a survey through the research panel. In the case of low levels of Disinhibition, the positive...
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Fatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C)
Dane BadawczeFatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C)
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Fatigue data of Cement Bitumen Treated Material Mixture C3E5.5 (over 28 days of curing at 20C, field cores)
Dane BadawczeDataset presents data of fatigue life determined for cold recycled mixture – cement bitumen treated material mixture with following binding agents: 3% cement and 5.5% emulsion (C3E5.5). Mixture was designed according to Polish requirements for the base course of pavement. Mixture contains 60% of RAP material. Specimen size: f=100 mm, h=48,4 - 70,9 mm.
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Rotordynamic characteristics of a chamber seal
PublikacjaThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal of a modernized type. The experiments were performed on a single-stage air model turbine of the impulse type. The experiments were performed on a single-stage air model turbine of the impulse type. The experimental data were compared with theoretical results obtained by means of CFD Fluent Code....
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Applying of the optical time-of-flight spectroscopy for the paper and pulp characterization
PublikacjaW pracy przedstawiono korzyści wykorzystania optycznej spektroskopii czasu przelotu w badaniach papieru i miazgi drzewnej. Przedmiotem badań były różne gatunki papieru oraz miazgi drzewnej (bez obróbki cieplnej, po obróbce cieplnej lub po obróbce chemicznej). W pomiarach wykorzystano półprzewodnikowe lasery impulsowe oraz w charakterze fotoodbiorników kamerę smugową lub licznik fotonów.
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Probing the Magnetic Anisotropy of Co(II) Complexes Featuring Redox-Active Ligands
PublikacjaCoordination complexes that possess large magnetic anisotropy (otherwise known as zero-field splitting, ZFS) have possible applications in the field of magnetic materials, including single molecule magnets (SMMs). Previous studies have explored the role of coordination number and geometry in controlling the magnetic anisotropy and SMM behavior of high-spin (S = 3/2) Co(II) complexes. Building upon these efforts, the present work...
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An image processing approach for fatigue crack identification in cellulose acetate replicas
PublikacjaThe cellulose acetate replication technique is an important method for studying material fatigue. However, extracting accurate information from pictures of cellulose replicas poses challenges because of distortions and numerous artifacts. This paper presents an image processing procedure for effective fatigue crack identification in plastic replicas. The approach employs thresholding, adaptive Gaussian thresholding, and Otsu binarization...
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Reduction of the Velocity Impact on the Magnetic Flux Leakage Signal
PublikacjaThe velocity effect on the magnetic flux leakage (MFL) signal was investigated in this paper. Experiments were performed for velocity of the MFL tool within the range of 0–2 m/s. The velocity was not constant during each measurement to imitate real operational conditions of the MFL tool. Two components of the leakage were measured, i.e. the tangential to the motion direction (x) and the normal to the investigated surface (z). In...
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Dynamic inequalities and equations of Volterra type on time scales
PublikacjaPraca dotyczy całkowo-różniczkowych równań dynamicznych typu Volterry z warunkami początkowymi. Stosując twierdzenie Banacha o punkcie stałym pokazano istnienie jedynego rozwiązania liniowego równania dynamicznego. Stosując metodę iteracji monotonicznych pokazano istnienie rozwiązań ekstremalnych dla problemów nieliniowych. Badano też nierówności dynamiczne. Praca zawiera również uwagi dotyczące zagadnień różniczkowych i różnicowych.
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Boundary value problems for dynamic equations of Volterra type on time scales
PublikacjaPraca dotyczy równań i nierówności dla problemów dynamicznych typu Volterry. Podano warunki dostateczne na istnienie ekstremalnych rozwiązań w obszarze ograniczonym przez dolne i górne rozwiązania. Praca zawiera również pewne uwagi dla konkretnych zagadnień różniczkowych i dyskretnych.
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On integro-differential equations with delayed arguments
PublikacjaPraca dotyczy problemów różniczkowo-całkowych z warunkami początkowymi oraz brzegowymi typu okresowego. Podano warunki na istnienie i jednoznaczność rozwiązania. Badania dotyczyły również nierówności różniczkowo-całkowych z argumentami typu opóżnionego. Podano przykłady, które mogą mieć zastosowanie w problemach inżynierskich.
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A 1-nS 1-V Sub-1-µW Linear CMOS OTA with Rail-to-Rail Input for Hz-Band Sensory Interfaces
PublikacjaThe paper presents an operational transconductance amplifier (OTA) with low transconductance (0.62–6.28 nS) and low power consumption (28–270 nW) for the low-frequency analog front-ends in biomedical sensor interfaces. The proposed OTA implements an innovative, highly linear voltage-to-current converter based on the channel-length-modulation effect, which can be rail-to-rail driven. At 1-V supply and 1-Vpp asymmetrical input driving,...
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Periodic Properties of 1D FE Discrete Models in High Frequency Dynamics
PublikacjaFinite element discrete models of various engineering 1D structures may be considered as structures of certain periodic characteristics. The source of this periodicity comes from the discontinuity of stress/strain field between the elements. This behaviour remains unnoticeable, when low frequency dynamics of these structures is investigated. At high frequency regimes, however, its influence may be strong enough to dominate calculated...
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User Orientation Detection in Relation to Antenna Geometry in Ultra-Wideband Wireless Body Area Networks Using Deep Learning
PublikacjaIn this paper, the issue of detecting a user’s position in relation to the antenna geometry in ultra-wideband (UWB) off-body wireless body area network (WBAN) communication using deep learning methods is presented. To measure the impulse response of the channel, a measurement stand consisting of EVB1000 devices and DW1000 radio modules was developed and indoor static measurement scenarios were performed. It was proven that for...
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The chemical and mechanical pressure influence on chromium luminescence
Dane BadawczeIn this study, we aim to compare the changes in the luminescence properties of Ga2O3:Cr3+ modified by Al or Sc ion substitution (chemical pressure) and hydrostatic pressure. We find the same behavior for Ga2–xAlxO3:Cr3+ and different behavior for Ga2–xScxO3:Cr3+ in terms of the optical properties under chemical and mechanical pressure. We consider Al...
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The vortex flow caused by sound in a bubbly liquid
PublikacjaGeneration of vorticity in the field of intense sound in a bubbly liquid in the free half-space is considered. The reasons for generation of vorticity are nonlinearity, diffraction, and dispersion. Acoustic streaming differs from that in a Newtonian fluid. Under some conditions, the vortex flow changes its direction. Conclusions concern streaming induced by a harmonic or an impulse Gaussian beam.
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A BRIEF REVIEW AND COMPARISON OF SELECTED EXPERIMENTAL METHODS FOR MEASURING NATURAL FREQUENCIES OF CIRCULAR SAW BLADES
PublikacjaDifferent methods for the empirical determination of the natural frequencies of circular saw blades are presented. Stationary methods, such as the harmonic and impulse tests, are discussed and the results of related comparison are given. The comparison of the methods revealed their degree of practical usefulness and their accuracy in determining natural frequencies. A combination of specific methods is proposed, which should allow...
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Nonlinear Properties of Seawater as a Factor Determining Nonlinear Wave Propagation
PublikacjaTaking practical advantage of nonlinear acoustical interactions occurring in seawater [1, 2] requires knowledge of the parameter of nonlinearity B=A of this medium. The literature does not offer much reports on B=A parameter value for seawater. In the few papers concerning that address the issue, results concerning ocean waters with high salinity and at large depths are given [3], while studies concerning seawater with low salinity...
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Self-adjusting sub-sample delay estimator based on fractional delaying Hilbert transform filter
PublikacjaZaprezentowano nowe rozwiązanie samo-nastrajalnego estymatora opóźnienia sygnału sinusoidalnego, działającego w czasie dyskretnym. Zastosowano filtr Hilberta o skończonej odpowiedzi ipulsowej (FIR od ang. finite impulse response) zagregowany z filtrem ułamkowo-opóźniającym. Zilustrowano performancję estymatora, również w obecności szumu. Przeanalizowano jego złożoność numeryczną.
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Regularized Identification of Time-Varying FIR Systems Based on Generalized Cross-Validation
PublikacjaA new regularization method is proposed and applied to identification of time-varying finite impulse response systems. We show, that by a careful design of the regularization constraint, one can improve estimation results, especially in the presence of strong measurement noise. We also show that the the most appropriate regularization gain can be found by direct optimization of the generalized cross-validation criterion.
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Erroneous GNSS Strain Rate Patterns and their Application to Investigate the Tectonic Credibility of GNSS Velocities
PublikacjaThe paper concerns investigation of the credibility of tectonic interpretation of GNSS strain rates. The analysis was focused on stable regions, where the crustal deformations are small and the reliability of GNSS velocities is questionable. We are showing how the unreliable motion of stations affects calculated strains around them. We expressed distribution of local principal strains by a sinusoidal function and used them to investigate...
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Stanowisko do badań odporności urządzeń na zaburzenia impulsowe
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Thin-walled cross section shape influence on steel member resistance.
PublikacjaThis work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into...
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Pressure Pulsations in Turbine Blade Seal
PublikacjaThe paper presents the results of experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type. The performed experimental research proved that in a shroud clearance the pressure pulsates and the effects of the nozzle trailing edge thickness as well as the influence of the rotor blades are observed. The exemplary results...
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Formowanie się akustycznego pola dyfuzyjnego w pomieszczeniach
PublikacjaW pracy omówiono znaną z literatury metodę wyznaczania wskaźnika rozproszenia dźwięku wykorzystującą odpowiedź impulsową pomieszczenia. Przy jej pomocy zbadano proces formowania się zjawiska rozproszenia dźwięku, co jest zilustrowane wzrostem wskaźnika rozproszenia w funkcji czasu. W tym celu poddano analizie odpowiedzi impulsowe dwóch pomieszczeń, różniących się kubaturą i czasem pogłosu. Uzyskano wykładniczy wzrost rozproszenia...
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Nowa koncepcja elektrody do oznaczeń elektrochemicznych - ''gorący czujnik''.
PublikacjaW artykule przedstawiono koncepcję nowego czujnika elektrochemicznego, w którym układ elektrod umieszczony jest na podgrzewanym izolatorze. Impulsowe podgrzewanie elektrod czujnika prowadzi do lokalnego wzrostu temperatury objętości roztworu znajdującej się w pobliżu elektrod. Wzrost temperatury prowadzi do wzrostu wartości współczynnika dyfuzji oznaczanych jonów, a tym samym do wzrostu wartości prądu dyfuzyjnego. Zwiększenie wartości...
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Procedury diagnostyczne badania izolacji maszyn elektrycznych
PublikacjaArtykuł opisuje stosowane w praktyce procedury diagnostyki off-line dla silników elektrycznych niskiego i średniego napięcia. Poza pomiarem rezystancji izolacji do eksploatacji wprowadza się metody impulsowe z dodatkową rejestracją impulsów wyładowań niezupełnych. Analiza odpowiedzi izolacji na oscylacyjne przebiegi napięcia zasadniczo poprawia możliwość wykrywania wewnętrznych uszkodzeń - w tym między zwojowych – w układzie...
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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowbandtransmission. Finally narrowband transmission quality in presence of modified ultrawideband...
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Formation of acoustic field in rooms
PublikacjaPaper describes known form literature method of sound diffusity index assesment, which utilizes impulse response of the room. Process of froming diffused sound field using this method was investigated.Increase of sound diffusity index in time was noted in rooms differing in shape,volume and reverberation time. Exponential growth of sound diffusion index was noted which correlates with other acoustical rooms measures.
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A New Method of Noncausal Identification of Time-varying Systems
PublikacjaThe paper shows that the problem of noncausal identification of a time-varying FIR (finite impulse response) sys- tem can be reformulated, and solved, as a problem of smoothing of the preestimated parameter trajectories. Characteristics of the smoothing filter should be chosen so as to provide the best trade- off between the bias and variance of the resulting estimates. It is shown that optimization of the smoothing operation can...
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Molecular hydrogen solvated in water – A computational study
PublikacjaThe aqueous hydrogen molecule is studied with molecular dynamics simulations at ambient temperature and pressure conditions, using a newly developed flexible and polarizable H2 molecule model. The design and implementation of this model, compatible with an existing flexible and polarizable force field for water, is presented in detail. The structure of the hydration layer suggests that first-shell water molecules accommodate the...
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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a UWB Signal
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. In the first part of paper, unmodified IEEE 802.15.4a IR UWB signal is used. Then some modification of transmitted pulse sequence is proposed, which allow to reduce UWB power spectral density at frequency of narrowband transmission. Finally narrowband transmission quality in presence of modified ultrawideband...
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Acoustic Streaming Induced by Periodic and Aperiodic Sound in a Bubbly Liquid
PublikacjaThe vortex ow which follows intense sound propagating in a bubbly liquid, is considered. The reasons for acoustic streaming are both nonlinearity and dispersion. That makes streaming especial as compared with that in a Newtonian uid. Conclusions concern the vortex ow induced in a half-space by initially harmonic or impulse Gaussian beam. The vortex ow recalls a turbulent ow with increasing in time number of small-scale vortices...
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A low-voltage CMOS negative impedance converter for analogue filtering applications
PublikacjaLow-voltage high-frequency continuous-time filters are still required in many applications and are the subject of continuing research. There are many techniques to realize integrated filters, including OTA C, Opamp RC and MOSFET-C-Opamp. The latter two show high dynamic range at low supply voltage, but their frequency operating range is usually limited to several megahertz. Transconductance filters are dedicated to higher frequencies....