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Search results for: FALSE POSITIVE SIGNAL
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Position Estimation in Corridors Along the Coupled Mode of Radiating Cables
PublicationRadiating cables are mostly used to provide radio communication in tunnels or corridors, but they can also be used to estimate the position of a mobile terminal along the cable. In this paper, a measuring receiver’s position was estimated by measuring the difference in the direct signal’s reception time, which was generated by a transmitter connected to one end of the radiating cable, and the delayed signal retransmitted from another...
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Atomic Force Microscope data post-processing algorithm for higher harmonics imaging
PublicationPrevious works have proved that higher harmonics topography imaging using atomic force microscope (AFM) can significantly enhanced its measurement capabilities. Integrated tools dedicated to most of microscopes allow to visualize the investigated surface only by one selected harmonic. Because of the different characteristics of a sample, scanning tip and the environment, appropriate harmonic selection is time consuming and requires...
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Compressive Sensing Approach to Harmonics Detection in the Ship Electrical Network
PublicationThe contribution of this paper is to show the opportunities for using the compressive sensing (CS) technique for detecting harmonics in a frequency sparse signal. The signal in a ship’s electrical network, polluted by harmonic distortions, can be modeled as a superposition of a small number of sinusoids and the discrete Fourier transform (DFT) basis forms its sparse domain. According to the theory of CS, a signal may be reconstructed...
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The Courts Public image - The Desired Direction of Change
PublicationThis paper proposes to scientifically explore notions of court identity, principles of shaping a court system's image, and best practices in positive court image development relating to thhe courts in Poland
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POPRAWA OBIEKTYWNYCH WSKAŹNIKÓW JAKOŚCI MOWY W WARUNKACH HAŁASU
PublicationCelem pracy jest modyfikacja sygnału mowy, aby uzyskać zwiększenie poprawy obiektywnych wskaźników jakości mowy po zmiksowaniu sygnału użytecznego z szumem bądź z sygnałem zakłócającym. Wykonane modyfikacje sygnału bazują na cechach mowy lombardzkiej, a w szczególności na efekcie podniesienia częstotliwości podstawowej F0. Sesja nagraniowa obejmowała zestawy słów i zdań w języku polskim, nagrane w warunkach ciszy, jak również w...
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A novel method of local chirp-rate estimation of LFM chirp signals in the time-frequency domain
PublicationIn the paper, novel dynamic representations of a complex signal in the time-frequency domain are introduced. The proposed approach is based on using the gradient of the short-time Fourier transform complex phase. A channelized instantaneous complex frequency (CICF) and a complex local group delay (CLGD) are included in the presented signal representations. An application of the newly-introduced distributions is demonstrated by...
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Multifrequency self-optimizing narrowband interference canceller
PublicationThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of a linear stable plant, is considered. It is assumed that disturbance is a multifrequency narrowband signal, and that system output is contaminated with wideband noise. It is not assumed that the reference signal is available. Two disturbance cancelling schemes are proposed, one for disturbances with unrelated frequency components, and...
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Parallel frequency tracking with built-in performance evaluation
PublicationThe problem of estimation of instantaneous frequency of a nonstationary complex sinusoid (cisoid) buried in wideband noise is considered. The proposed approach employs a bank of adaptive notch filters, extended with a nontrivial performance assessment mechanism which automatically chooses the best performing filter in the bank. Additionally, a computationally attractive method of implementing the bank is proposed. The new structure...
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Self-tuning adaptive frequency tracker
PublicationAn automatic gain tuning algorithm is proposed for a recently introduced adaptive notch filter. Theoretical analysis and simulations show that, under Gaussian random-walk type assumptions, the proposed extension is capable of adjusting adaptation gains of the filter so as to minimize the mean-squared frequency tracking error without prior knowledge of the true frequency trajectory. A simplified one degree of freedom version of...
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Identification of nonstationary multivariate autoregressive processes– Comparison of competitive and collaborative strategies for joint selection of estimation bandwidth and model order
PublicationThe problem of identification of multivariate autoregressive processes (systems or signals) with unknown and possibly time-varying model order and time-varying rate of parameter variation is considered and solved using parallel estimation approach. Under this approach, several local estimation algorithms, with different order and bandwidth settings, are run simultaneously and compared based on their predictive performance. First,...
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Histogram of Oriented Gradients with Cell Average Brightness for Human Detection
PublicationA modification of the descriptor in a human detector using Histogram of Oriented Gradients (HOG) and Support Vector Machine (SVM) is presented. The proposed modification requires inserting the values of average cell brightness resulting in the increase of the descriptor length from 3780 to 3908 values, but it is easy to compute and instantly gives ≈ 25% improvement of the miss rate at 10‒4 False Positives Per Window (FPPW). The...
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Analysis of Lombard speech using parameterization and the objective quality indicators in noise conditions
PublicationThe aim of the work is to analyze Lombard speech effect in recordings and then modify the speech signal in order to obtain an increase in the improvement of objective speech quality indicators after mixing the useful signal with noise or with an interfering signal. The modifications made to the signal are based on the characteristics of the Lombard speech, and in particular on the effect of increasing the fundamental frequency...
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Estimation of Coherence Bandwidth for Underwater Acoustic Communication Channel
PublicationA shallow underwater acoustic communication channel is characterized by strong multipath propagation. The signal reaching the receiver consists of a direct waveform and a number of its delayed and suppressed replica. A significant time dispersion of the transmitted signal and selective fading of its spectrum are observed. Coherence bandwidth defines maximal bandwidth, wherein the channel amplitude characteristic remains constant...
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Investigating Feature Spaces for Isolated Word Recognition
PublicationMuch attention is given by researchers to the speech processing task in automatic speech recognition (ASR) over the past decades. The study addresses the issue related to the investigation of the appropriateness of a two-dimensional representation of speech feature spaces for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and timefrequency signal representation...
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Magdalena Szuflita-Żurawska
PeopleHead of the Scientific and Technical Information Services at the Gdansk University of Technology Library and the Leader of the Open Science Competence Center. She is also a Plenipotentiary of the Rector of the Gdańsk University of Technology for open science. She is a PhD Candidate. Her main areas of research and interests include research productivity, motivation, management of HEs, Open Access, Open Research Data, information...
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Properties and interpretation of Instantaneous Complex Frequency
PublicationThe concept of Instantaneous Complex Frequency (ICF) was first defined by Lindon and developed mainly in works of two authors S. Hahn and M. Rojewski. Although it is not widely used in signal analysis, ICF was already used as a complex signal representation in the verification of handwritten signatures, pitch estimation, symbol timing recovery in PSK receiver and in detection of anomalies in data transmission. It should be noted,...
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Detection of impulsive disturbances in archive audio signals
PublicationIn this paper the problem of detection of impulsive disturbances in archive audio signals is considered. It is shown that semi-causal/noncausal solutions based on joint evaluation of signal prediction errors and leave-one-out signal interpolation errors, allow one to noticeably improve detection results compared to the prediction-only based solutions. The proposed approaches are evaluated on a set of clean audio signals contaminated...
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A body position influence on ECG derived respiration
PublicationAn influence of a human body position on ECG derived respiration (EDR) signal is presented in the paper. Examinations were performed during deep, suspended and normal breathing for eight people in four different body positions. EDR and thoracic impedance signals were compared using correlation and standard deviation coefficients. Obtained results have shown that it is possible to monitor breath activity of people being in different...
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From the multiple frequency tracker to the multiple frequency smoother
PublicationThe problem of extraction/elimination of nonstationary sinusoidalsignals from noisy measurements is considered. This problem is usually solved using adaptive notch filtering (ANF)algorithms. It is shown that the accuracy of frequency estimates can be significantly increased if the results obtained from ANF are backward-time filtered by an appropriately designed lowpass filter. The resulting adaptive notch smoothing (ANS)algorithm...
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Job satisfaction in the multicultural environment of multinational corporations
PublicationPurpose – Since prior research into the effects of multiculturalism on job satisfaction in multinational corporations (MNCs) is rather scant and inconclusive, the authors attempt to review the literature and explain why these results are inconsistent as well as propose a new model aimed at responding to these irregularities. Design/methodology/approach – In the narrative review of the prior research and the proposed model the...
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Thriving in multicultural workplace
PublicationThriving at work is defined as the psychological state that links both a sense of vitality and learning. The vitality component of thriving may be seen as positive energy, while learning enhances a sense of competence and efficacy. Thriving sheds new light on individual psychological functioning and the experience of growth in the work context. Thriving at work promotes growth through playing an active role in interaction with...
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Analiza stanu nawierzchni i klas pojazdów na podstawie parametrów ekstrahowanych z sygnału fonicznego
PublicationCelem badań jest poszukiwanie parametrów wektora cech ekstrahowanego z sygnału fonicznego w kontekście automatycznego rozpoznawania stanu nawierzchni jezdni oraz typu pojazdów. W pierwszej kolejności przedstawiono wpływ warunków pogodowych na charakterystykę widmową sygnału fonicznego rejestrowanego przy przejeżdżających pojazdach. Następnie, dokonano parametryzacji sygnału fonicznego oraz przeprowadzano analizę korelacyjną w celu...
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A new approach to active noise and vibration control - [Part II: unknown frequency case]
PublicationThis paper presents a new approach to rejection of complex-valued sinusoidal disturbances acting at the output of a discrete-time stable linear plant with unknown and possibly timevarying dynamics. It is assumed that both the instantaneous frequency of the sinusoidal disturbance and its amplitude may be slowly varying with time and that the output signal is contaminated with wideband measurement noise. It is not assumed that a...
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Multichannel Human Body Communication
PublicationHuman Body Communication is an attractive alternative for traditional wireless communication (Bluetooth, ZigBee) in case of Body Sensor Networks. Low power, high data rates and data security makes it ideal solution for medical applications. In this paper, signal attenuation for different frequencies, using FR4 electrodes, has been investigated. Performance of single and multichannel transmission with frequency modulation of analog...
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Pozytywne doświadczenia zakupowe w kreowaniu lojalności nabywczej
PublicationDoświadczenie zakupowe to rodzaj mentalnej podróży, pozostawiającej niematerialne wrażenia, w postaci wiedzy i śladu emocjonalnego [69], będące kluczowym elementem w zrozumieniu zachowań konsumentów, jak również istotnych zmian zachodzących we współczesnym marketingu [10]. Cel: Celem głównym badań było ukazanie wpływu pozytywnych doświadczeń zakupowych na kształtowanie satysfakcji i lojalności nabywczej oraz sposobów budowania...
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Stock Markets’ Reactions to the Announcement of the Hosts. An Event Study in the Analysis of Large Sporting Events in the Years 1976–2032
PublicationThis study attempts to estimate the impact of the announcements of hosts of large sporting events on domestic stock markets. The research problem is to establish a connection between the uniqueness of a sporting event and investors’ beliefs through stock price behavior. Using appropriate estimation windows, 13 different sporting events classified as large, including mega and major events, were tested. The obtained results show...
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On adaptive covariance and spectrum estimation of locally stationary multivariate processes
PublicationWhen estimating the correlation/spectral structure of a locally stationary process, one has to make two important decisions. First, one should choose the so-called estimation bandwidth, inversely proportional to the effective width of the local analysis window, in the way that complies with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive...
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Selection of effective cocrystals former for dissolution rate improvement of active pharmaceutical ingredients based on lipoaffinity index
PublicationNew theoretical screening procedure was proposed for appropriate selection of potential cocrystal formers possessing the ability of enhancing dissolution rates of drugs. The procedure relies on the training set comprising 102 positive and 17 negative cases of cocrystals found in the literature. Despite the fact that the only available data were of qualitative character, performed statistical analysis using binary classification...
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Effect of the North Atlantic Thermohaline Circulation on changes in climatic conditions and river flow in Poland
Publication: The purpose of this study is to find connections between the North Atlantic Thermohaline Circulation (NA THC), climate elements, such as cloud cover, precipitation, air temperature, sunshine duration, and relative humidity, and flow of rivers in Poland. The intensity of NA THC was characterized by the DG3L index, which was established to assess changes in the amount of heat transported by NA THC along with the transport of water...
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Rothe’s method for physiologically structured models with diffusion
PublicationWe consider structured population models with diffusion and dynamic boundary conditions. The respective approximation, called Rothe’s method, produces positive and exponentially bounded solutions. Its solutions converge to the exact solution of the original PDE.
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The conducted immunity test of a power supply unit in accordance with EMC standards
Open Research DataThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the DF1723003TC NDN power supply. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 150 kHz to 230 MHz are...
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Invasive Assessment of the Myocardial Microcirculation during Beating Heart Coronary Artery Bypass Grafting
PublicationCoronary artery bypass grafting may be associated with several cardiac complications, including ischemia, acute myocardial infarction, arrhythmias, or hemodynamic instability. Accumulating evidence suggests that well-developed coronary collateral circulation may protect against adverse effects, including myocardial ischemia. Assessment of myocardial microvascular perfusion is, therefore, of great clinical interest in beating heart...
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The conducted immunity test of a power supply unit in the frequency range from 19 MHz to 26 MHz for the RF voltage level of 3 V
Open Research DataThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the DF1723003TC NDN power supply unit. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 19 MHz to 26 MHz were...
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The conducted immunity test of a power supply unit in the frequency range from 19 MHz to 26 MHz for the RF voltage level of 1 V
Open Research DataThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the DF1723003TC NDN power supply unit. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 19 MHz to 26 MHz were...
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The conducted immunity test of a power supply unit in the frequency range from 19 MHz to 26 MHz for the RF voltage level of 10 V
Open Research DataThe dataset presents a result of measurements that are a part of immunity tests to conducted disturbances, induced by radio-frequency fields. The immunity tests were carried out on the mains cable of the DF1723003TC NDN power supply unit. Tests of immunity of electronic systems to conducted disturbances in the frequency range from 19 MHz to 26 MHz were...
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Blood Pressure Estimation Based on Blood Flow, ECG and Respiratory Signals Using Recurrent Neural Networks
PublicationThe estimation of systolic and diastolic blood pressure using artificial neural network is considered in the paper. The blood pressure values are estimated using pulse arrival time, and additionally RR intervals of ECG signal together with respiration signal. A single layer recurrent neural network with hyperbolic tangent activation function was used. The average blood pressure estimation error for the data obtained from 21 subjects...
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Photoplethysmographic Time-Domain Heart Rate Measurement Algorithm for Resource-Constrained Wearable Devices and its Implementation
PublicationThis paper presents an algorithm for the measurement of the human heart rate, using photoplethysmography (PPG), i.e., the detection of the light at the skin surface. The signal from the PPG sensor is processed in time-domain; the peaks in the preprocessed and conditioned PPG waveform are detected by using a peak detection algorithm to find the heart rate in real time. Apart from the PPG sensor, the accelerometer is also used to...
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Methodology and technology for the polymodal allophonic speech transcription
PublicationA method for automatic audiovisual transcription of speech employing: acoustic and visual speech representations is developed. It adopts a combining of audio and visual modalities, which provide a synergy effect in terms of speech recognition accuracy. To establish a robust solution, basic research concerning the relation between the allophonic variation of speech, i.e. the changes in the articulatory setting of speech organs for...
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Methodology and technology for the polymodal allophonic speech transcription
PublicationA method for automatic audiovisual transcription of speech employing: acoustic, electromagnetical articulography and visual speech representations is developed. It adopts a combining of audio and visual modalities, which provide a synergy effect in terms of speech recognition accuracy. To establish a robust solution, basic research concerning the relation between the allophonic variation of speech, i.e., the changes in the articulatory...
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Application of IR UWB Spectrum Shaping to IEEE 802.15.4a Standard
PublicationCoexistence of existing narrowband systems and new ultra wideband devices in the same frequency range requires using some interference mitigation techniques, for example based on spectrum shaping. This paper presents efficiency of impulse radio spectrum shaping methods, applied to IEEE 802.15.4a UWB alternate physical layer signals. Basic parameters of 802.15.4a signal structure and outline of proposed spectrum shaping methods...
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Using phase of short-term Fourier transform for evaluation of spectrogram performance
PublicationThe concept of spectrogram performance evaluation which exploits information on phase of short-term Fourier transform (STFT) is presented. A spectrograph which is time-frequency analyzing tool, is compared to a filter bank that demultiplexes a signal. Local group delay (LGD) and channelized instantaneous frequency (CIF) is obtained for each filtered component signal. In presented solution the performance is evaluated using so-called...
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New results on estimation bandwidth adaptation
PublicationThe problem of identification of a nonstationary autoregressive signal using non-causal estimation schemes is considered. Noncausal estimators can be used in applications that are not time-critical, i.e., do not require real-time processing. A new adaptive estimation bandwidth selection rule based on evaluation of pseudoprediction errors is proposed, allowing one to adjust tracking characteristics of noncausal estimators to unknown...
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Design, Realization and Measurements of Enhanced Performance 2.4 GHz ESPAR Antenna for Localization in Wireless Sensor Networks
PublicationThis paper presents the design, realization and measurements of an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna with enhanced performance of estimating the incoming signal direction. Designed antenna is dedicated for 2.4 GHz ISM applications with emphasis on Wireless Sensor Networks (WSN). Proposed antenna provides different radiation patterns by proper configuration of the parasitic elements. Thus, several...
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The role of trade in intra industry productivity growth - the case of old and new European Union countries.
PublicationThe purpose of this paper is to evaluate the role of trade in productivity growth in a sample of 30 sectors in 25 EU countries in the period of rapid East–West integration (1995–2007). Shift-share analysis is used to show that changes in value added per hour worked in these countries appear to be mainly due to positive developments (rising productivity) within single industries and only to a lower extent result from a shift towards...
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Low-dimensional bound entanglement with one-way distillable cryptographic key
PublicationIn this paper, we provide a class of bound entangled states that have positive distillable secure key rate. The smallest state of this kind is 4 circle times 4, which shows that peculiar security contained in bound entangled states does not need high-dimensional systems. We show that for these states a positive key rate can be obtained by one-way Devetak-Winter (DW) protocol. Subsequently, the volume of bound entangled key-distillable...
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Driving the Image of an Electricity Supplier through Marketing Activities
PublicationThe aim of this study is to determine how marketing actions undertaken within the marketing mix by electricity providers influence their image. Referring to the Stimulus-Organism-Response (SOR) theory, research hypotheses were formulated, and a regression model was constructed, assuming positive impacts of selected marketing actions of electricity providers on their image. A quantitative approach was employed to test the research...
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Janusz Nieznański prof. dr hab. inż.
PeopleJanusz Nieznański born in 1957 in Gdańsk. He received the M.Sc. degree in 1981, the Ph.D. degree in 1990, and the D.Sc. (‘habilitation’) degree in 1999, all from the Gdańsk University of Technology. Since 1981 he has been with the above university, where he is currently Professor of Electrical Engineering. His research and teaching interests include control, diagnostics, modeling and simulation of power electronic converters and...
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Adrian Kastrau mgr inż.
People -
Adam Smith - pięć razy o racjonalności w ekonomii (Z okazji 240 rocznicy ukazania się "Bogactwa Narodów").
PublicationNiniejszy tekst jest syntetyczną próbą, próbą wykraczającą poza ramy samej ekonomii i wkraczającą w pole filozofii, socjologii i antropologii, umiejscowienia myśli Adama Smitha w szerszej perspektywie, perspektywie mechanizmów kształtowania się w nowożytności nowego rodzaju społeczeństwa i związanych z tym zmian mentalnych mających odbicie w myśli europejskiej. Ogrom problematyki zawęża temat do fundamentalnego dla ekonomii jako...
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An Instantaneous Engine Speed Estimation Method Using Multiple Matching Synchrosqueezing Transform
PublicationInstantaneous rotational speed measurement of the engine is crucial in routine inspection and maintenance of an automobile engine. Since the contact measurement of rotational speed is not always available, the vibration measurement has been used for noncontact rotational speed estimation methods. Unfortunately, the accuracy of the noncontact estimation methods by analyzing engine vibration frequency is not satisfactory due to the...