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1
Siebert, Markus, Sebastian Hagemeier, Tobias Pahl, Hüseyin Serbes, and Peter Lehmann. "Modeling of fiber-coupled confocal and interferometric confocal distance sensors." Measurement Science and Technology 33, no. 7 (April 6, 2022): 075104. http://dx.doi.org/10.1088/1361-6501/ac5f29.
Повний текст джерелаАнотація:
Abstract Laser distance sensors are a widespread, fast and contactless approach for distance and surface topography measurements. Main characteristics of those sensors are given by resolution, measurement speed and sensor geometry. With decreasing sensor size, the alignment of the optical components in sensor setup becomes more challenging. The depth response of optical profilers is analyzed to obtain characteristic parameters and, thus, to value the alignment and the transfer behavior of those sensors. We present a novel miniaturized sensor setup comprising of confocal and interferometric confocal signals within one sensor in order to compare both principles simply by obscuring the reference arm by an absorber. Further, we introduce a theoretical signal modeling in order to analyze influences such as spatial coherence, Gaussian beam characteristics and tilted reflectors on depth response signals. In addition to this, we show that the coherent superposition significantly reduces the axial resolution due to the confocal effect in interferometric signals compared to simple confocal signals in measurement and simulation results. Finally, an appropriate fit function is presented, in order to figure out characteristic sensor parameters from the obtained depth response signal. In this context, a good agreement to simulated and measured signals is achieved.
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Губін, Сергій Вікторович, Сергій Олександрович Тишко, Олег Євгенович Забула та Юрій Миколайович Черниченко. "ОСЦИЛОГРАФІЧНИЙ МЕТОД ВИМІРЮВАННЯ ФАЗОВОГО ЗСУВУ НА БАЗІ ДВОНАПІВПЕРІОДНОГО ПЕРЕТВОРЕННЯ". RADIOELECTRONIC AND COMPUTER SYSTEMS, № 4 (25 грудня 2019): 47–54. http://dx.doi.org/10.32620/reks.2019.4.05.
Повний текст джерелаАнотація:
The subject matter of the article is the oscilloscope methods of measuring the phase shift of two harmonic signals, after carrying out their two-half-period transformation and summing. The goal is to develop ways to implement an oscilloscope method of measuring the phase shift of two harmonic signals, which will significantly reduce the component of measurement error caused by phase non-symmetry of the transmission channels, by reducing their length. Analyze the measurement error for each of the methods for determining the phase shift of two harmonic signals using their two-half-periodic transformation. The tasks: statement of measurement problem of determination of phase shift of two harmonic signals; analysis of known oscilloscope methods of phase shift measurement, development of methods for implementing the oscilloscope method based on the analysis of the characteristics of the total signal obtained during the two-half-period transformation; estimation of measurement errors for each method. The methods used are the methodology for estimating measurement errors in indirect measurements. The following results were obtained. Methods for implementing an oscilloscope measurement method using the total signal after a two-half-period transformation based on the analysis of temporal characteristics and local extrema of this signal are proposed. The list of measuring operations that implement each method is defined. The analysis of the components of measurement errors was performed and the degree of correlation was determined. Synthesized ratios for the calculation of measurement error. Conclusions. The scientific novelty of the obtained results is the following: an oscilloscopic method has been developed that will allow reducing substantially the component of the error caused by phase non-symmetry of the signal transmission channels; obtained ratios for the implementation of the oscilloscope measurement method using two-half-period conversion; obtained ratios to calculate the standard deviation of the total measurement error in each of the proposed methods.
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Lagun, Andrii, Oleksandr Mamro, and Volodymyr Yalechko. "STUDY OF THE DIELECTRIC CHARACTERISTICS OF INDUSTRIAL WOOD." Measuring Equipment and Metrology 82, no. 4 (2021): 8–11. http://dx.doi.org/10.23939/istcmtm2021.04.008.
Повний текст джерелаАнотація:
In the article, we consider the model of pulse signal distortion in the computer sound card channel. The use of such a model allows expanding the possibilities of using computers in the researches of the wood properties in the form of various dielectric characteristics analysis, in particular using the computer sound card channel. This makes it possible to verify the state of the signal propagation channel during the experiment. This experiment researches samples of wood for the presence of defects. Also is proposed an approach to constructing the distortion model. It allows to expand the possibilities of investigating the parameters of the pulse signal and to verification the state of the channel during the research of the dielectric properties of wood. To research, a sample of wood using a computer sound card is developed a structured scheme that allows you to analyze the characteristics of pulse signals during the measurement process. To determine the dielectric parameters of different types of industrial wood is developed the software in the MATLAB environment. Using it is analyzed complex pulse signals that used during the research. In particular, were taken into account different currents of wood polarization and dielectric characteristics.
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Bogachev, N., S. Andreev, V. Dyomin, N. Guseyn-zade, A. Kirillov, O. Kalinin, and A. Filippov. "PLASMA ASYMMETRICAL DIPOLE ANTENNA: THE MEASUREMENT OF SIGNAL CHARACTERISTICS." ELECTRONICS: Science, Technology, Business, no. 1 (2018): 88–91. http://dx.doi.org/10.22184/1992-4178.2018.172.1.88.91.
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Xu, Junshu, Changlong Xu, Deming Xu, and Xuexia Yang. "Diode large-signal characteristics measurement for high-power rectennas." Microwave and Optical Technology Letters 45, no. 3 (2005): 249–51. http://dx.doi.org/10.1002/mop.20786.
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Antonets, M. A., and N. A. Sidorovskaya. "Estimation of random-signal-source characteristics by field measurement." Radiophysics and Quantum Electronics 36, no. 8 (August 1993): 573–75. http://dx.doi.org/10.1007/bf01038439.
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Sheng, Xiaofei, Jianguo Shen, Yongjin Shen, Liufang Zhu, and Defu Zang. "Measurement of formation conductivity through-casing using a TEM method." Journal of Geophysics and Engineering 16, no. 2 (April 1, 2019): 439–50. http://dx.doi.org/10.1093/jge/gxz022.
Повний текст джерелаАнотація:
Abstract Due to the existence of the metal casing in production wells, it is difficult for a conventional well-logging method to achieve satisfactory results. To study the possibility of measuring the formation conductivity through casing by using a transient electromagnetic (TEM) method, characteristics of the response signals received at different source-receiver spacing are investigated. Based on the advantages of the response signals at long spacing in the separation of the direct and indirect coupled signals, the corresponding differential response signals calculated with different formation conductivities are studied further. Results show that: (1) the differential signals are three orders of magnitude smaller than that of the original response signals; (2) there is a maximum and a minimum in the differential signal; (3) with the increase of the spacing, the profile of differential signal hardly changes, but moves backward on the timeline and the amplitude decreases slowly, which is in sharp contrast to the original response signals and (4) the differential signal is proportional to the difference of corresponding formation conductivities and the maximum and minimum values in the response difference are the most sensitive. The research reveals the characteristics of TEM responses in cased-hole and the distribution of formation conductivity information, which is predicted to provide a new perspective for the design of long-spacing through-casing in the TEM conductivity logging tool and the signal processing method.
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Ju, Bin, Yun Tao Qian, and Huo Jie Ye. "Wavelet Based Measurement on Photoplethysmography by Smartphone Imaging." Applied Mechanics and Materials 380-384 (August 2013): 773–77. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.773.
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[Purpose] Smartphones video cameras can be used to detect the photoplethysmograph (PPG) signal.The pulse wave signal detected by smartphone always mixed mass noise because of finger moving, unevenness of pressure and outer light interference. Previous studies limit to the filtering algorithm that denoising signals, without considering characteristics information of pulse wave itself. [Method] In this paper, we propose an algorithm based on wavelet to detect qualified PPG, which captures three critical characteristic quantities through wavelet high frequency coefficient. [Results] Experiment illustrates that the detected PPG signal contain dicrotic wave, and whats more, further experiment on artery elasticity indexes indicates good robust of the algorithm. [Conclusions] Wavelet Based Measurement on Photoplethysmography by Smartphone Imaging can be used for the calculation of cardiovascular parameter such as angiosclerosis, arrhythmia, and vascular resistance.
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Andris, Peter, Tomáš Dermek, and Ivan Frollo. "Calibration of NMR Receiver using Spectrometer Characteristics." Measurement Science Review 21, no. 6 (October 26, 2021): 205–8. http://dx.doi.org/10.2478/msr-2021-0028.
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Abstract This article describes the measurement of the relation between input and output signals using two techniques: with a signal generator and with the thermal noise of a known resistance. Each of the techniques has its advantages and disadvantages. Both methods are tested and the results are compared. The input signal of the receiver is known in volts, while the output signal is in ADC (analogue-to-digital converter) units. It is the main difference versus the gain. Knowledge of the relation enables recalculation of the output signal into the input of the receiver or vice versa. It is important in some experiments. The method with the harmonic signal requires a suitable NMR spectroscopic console, generator of the harmonic signal and an attenuator, the method with the noise requires only the NMR console. It indicates that both methods are simple and cheap. The measured data are processed on a standard PC using common programs.
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Wang, Jun, Zhenya Zhu, Yongxin Gao, Frank Dale Morgan, and Hengshan Hu. "Measurements of the seismoelectric responses in a synthetic porous rock." Geophysical Journal International 222, no. 1 (May 4, 2020): 436–48. http://dx.doi.org/10.1093/gji/ggaa174.
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SUMMARY Seismoelectric measurements are conducted with a synthetic porous rock sample to model an ocean exploration. Two kinds of seismoelectric coupling signals, that is, the interfacial EM wave signal and the coseismic electric signal, have been recorded by the electrodes buried inside a rock sample instead of those located in the fluid or in the solid region near the interface as performed in previous works. These seismoelectric signals are clearly observed and identified with a high signal-to-noise ratio. The characteristics of the measured interfacial EM wave and coseismic electric signals are analysed with the experimental data. We also simulate the seismoelectric conversion fields and make a comparison between the measured and simulated seismoelectric signals. The result shows that the simulated and measured signals match well for both the interfacial EM wave and the coseismic electric fields accompanying the fast P wave. Our results also show that the amplitudes of seismoelectric signals are in the order of tens to hundreds of microvolts with our experimental system. This confirms that the seismoelectric signals are measurable in the interior of the rocks with current measurement techniques, suggesting the seismoelectric measurement to be a potential method for studying characteristics of the material beneath the seafloor.
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Zhu, Mengyun, Ximin Fan, Weijing Liu, Jianying Shen, Wei Chen, Yawei Xu, and Xuejing Yu. "Artificial Intelligence-Based Echocardiographic Left Atrial Volume Measurement with Pulmonary Vein Comparison." Journal of Healthcare Engineering 2021 (December 6, 2021): 1–11. http://dx.doi.org/10.1155/2021/1336762.
Повний текст джерелаАнотація:
This paper combines echocardiographic signal processing and artificial intelligence technology to propose a deep neural network model adapted to echocardiographic signals to achieve left atrial volume measurement and automatic assessment of pulmonary veins efficiently and quickly. Based on the echocardiographic signal generation mechanism and detection method, an experimental scheme for the echocardiographic signal acquisition was designed. The echocardiographic signal data of healthy subjects were measured in four different experimental states, and a database of left atrial volume measurements and pulmonary veins was constructed. Combining the correspondence between ECG signals and echocardiographic signals in the time domain, a series of preprocessing such as denoising, feature point localization, and segmentation of the cardiac cycle was realized by wavelet transform and threshold method to complete the data collection. This paper proposes a comparative model based on artificial intelligence, adapts to the characteristics of one-dimensional time-series echocardiographic signals, automatically extracts the deep features of echocardiographic signals, effectively reduces the subjective influence of manual feature selection, and realizes the automatic classification and evaluation of human left atrial volume measurement and pulmonary veins under different states. The experimental results show that the proposed BP neural network model has good adaptability and classification performance in the tasks of LV volume measurement and pulmonary vein automatic classification evaluation and achieves an average test accuracy of over 96.58%. The average root-mean-square error percentage of signal compression is only 0.65% by extracting the coding features of the original echocardiographic signal through the convolutional autoencoder, which completes the signal compression with low loss. Comparing the training time and classification accuracy of the LSTM network with the original signal and encoded features, the experimental results show that the AI model can greatly reduce the model training time cost and achieve an average accuracy of 97.97% in the test set and increase the real-time performance of the left atrial volume measurement and pulmonary vein evaluation as well as the security of the data transmission process, which is very important for the comparison of left atrial volume measurement and pulmonary vein. It is of great practical importance to compare left atrial volume measurements with pulmonary veins.
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Lin, Wei, and Jing-Lei Zhao. "A Novel Method Based on Hilbert Transform for Signal Processing of Coriolis Mass Flowmeter." International Journal of Pattern Recognition and Artificial Intelligence 32, no. 02 (November 12, 2017): 1858001. http://dx.doi.org/10.1142/s0218001418580016.
Повний текст джерелаАнотація:
The signal phase differences of Coriolis sensor and the mass flow are proportional. To improve the measurement accuracy of flow signal processing for Coriolis mass flowmeter, a novel method based on Hilbert Transform algorithm was proposed. The main method is as follows, two signals enhanced by LZ-filter with noise-canceling were considered as Hilbert Transform, then, the phase difference of the two filtered signals was calculated by a triangle characteristic of sin function. Synchronously, the instantaneous frequency was estimated by the structure of the analytical signal. Finally, the mass flow value was obtained by calculating the phase difference. The simulation experiments and Digital Signal Processing system (DSP) verification testing demonstrate that the new signal processing method, which is the LZ algorithm, has better characteristics of real-time and high-precision than the others. The experimental results show that the accuracy of phase difference measurement is 0.02% and the tracking accuracy of frequency is better than 0.07%.
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Majchrzak, Jarosław, and Grzegorz Wiczyński. "Basic Characteristics of IEC Flickermeter Processing." Modelling and Simulation in Engineering 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/362849.
Повний текст джерелаАнотація:
Flickermeter is a common name for a system that measures the obnoxiousness of flicker caused by voltage fluctuations. The output of flickermeter is a value of short-term flicker severity indicator, . This paper presents the results of the numerical simulations that reconstruct the processing of flickermeter in frequency domain. With the use of standard test signals, the characteristics of flickermeter were determined for the case of amplitude modulation of input signal, frequency modulation of input signal, and for input signal with interharmonic component. For the needs of simulative research, elements of standard IEC flickermeter signal chain as well as test signal source and tools for acquisition, archiving, and presentation of the obtained results were modeled. The results were presented with a set of charts, and the specific fragments of the charts were pointed out and commented on. Some examples of the influence of input signal’s bandwidth limitation on the flickermeter measurement result were presented for the case of AM and FM modulation. In addition, the diagrams that enable the evaluation of flickermeter’s linearity were also presented.
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Petrovic, Vesna, Nikola Stojanovic, Milos Slankamenac, and Svetlana Lukic. "Amplifying characteristics Er-doped chalcogenide glass." Chemical Industry 64, no. 3 (2010): 183–86. http://dx.doi.org/10.2298/hemind091221033p.
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The paper presents the measurement results of optical amplifying characteristics of Er-doped As-S-Ge chalcogenide glasses. The measurements included the amplification of useful laser source power during propagation along two axes of samples. A fluorescence maximum at the wavelengths between 1500 nm and 1540 nm was identified, which corresponds to the transition of electrons from the 4I13/2 level to the 4I15/2 level within the 4f shell of Erbium ions (Er3+). Measuring the signal strength showed that the passage through the erbium doped chalcogenid glass amplification of the useful signal occurs and this increase is proportional to the length of propagation through the doped glass.
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Zavgorodnii, Aleksei S. "The global navigation systems satellites signals partial powers measuring method." Izmeritel`naya Tekhnika, no. 9 (2021): 16–22. http://dx.doi.org/10.32446/0368-1025it.2021-9-16-22.
Повний текст джерелаАнотація:
Different consumers of global navigation satellite systems signals are able to receive different combinations of them. For this reason, it is important to monitor the signal parameters separately. The existing partial signals characteristics measuring methods are based on correlation processing, which leads to the loss of measurement information and signal averaging. A method for measuring the partial powers of navigation signals with frequency and code division was developed. The initial data are the total spectral power density measurements results, as well as information on the shape of the partial spectral power densities. A mathematical model of the sum of signals with overlapping spectra was investigated. It was shown that the signal powers were related as coefficients at partial spectral power densities. A system of equations for the coefficients is compiled, its solution is presented by the Tikhonov method. A practical study of the metrological characteristics of the method has been carried out. The research results will be used during monitoring the navigation spacecraft technical condition.
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Liu, Wei, and Tian Lan. "Analysis on the Characteristics of Transient Signal Transmission Based on GaAs Materials." Materials Science Forum 663-665 (November 2010): 502–5. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.502.
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The GaAs photoconductive switch is an important device in the measurement of the signal of ultra high-speed. In this paper, the transmission model of transient signals on GaAs photoconductive material is given, and the experimental system of near-field detection is set up. It is gotten that the full width half magnitude of signal is about 2ps. Based on the testing result of delay-time-modulation method, the relationship between signal amplitude and the form of connection mode is analyzed and discussed. It is shown that the coupling of capacity is important to acquire the transient signal.
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Kłapyta, Grzegorz, and Marek Kciuk. "Experimental measurements of shape memory alloys wires." Archives of Electrical Engineering 61, no. 2 (June 1, 2012): 129–38. http://dx.doi.org/10.2478/v10171-012-0012-4.
Повний текст джерелаАнотація:
Experimental measurements of shape memory alloys wires Paper deals with examinations of properties of shape memory alloy actuators. Authors describe design of own laboratory stand for obtaining electro-thermo-mechanical characteristics of SMA wires (maximum length 900 mm). The stand allows for semi-automatic measurements of voltage and current (supplying the actuator), temperature of wire and its extension. Data acquisition and control signals are realized by PC computer. All elements of the measuring system are connected by GPIB network (IEEE 488.2 standard). Control program for static measurements was written in G language (LabVIEW environment). Temperature is measured using infrared camera Flir A325. Displacement measurement system contains optical sensor (converting piston movement into series of pulses), pulses counter, PWM signal generator (PWM signal fulfillment is proportional to number of pulses), lowpass filter and buffer conditioning external signal. For dynamic measurements data recording is performed using digital oscilloscope Tektronix MSO 2024 equipped with four separated channels and digital filter. Wide range of examinations of several SMA wires allowed for drawing its exploitative characteristic helpful for practical use. It shows length change of actuator as a function of mechanical load (Fig. 10). Finally some example static as well as dynamic characteristics are presented and short discussion is carried out.
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Abdullah, Abdul Rahim, N. A. Abidullah, N. H. Shamsudin, N. H. H. Ahmad, and M. H. Jopri. "Performance Verification of Power Quality Signals Classification System." Applied Mechanics and Materials 752-753 (April 2015): 1158–63. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.1158.
Повний текст джерелаАнотація:
Power quality has become a greater concern nowadays. The increasing number of power electronics equipment contributes to the poor quality of electrical power supply. The power quality signals will affect manufacturing process, malfunction of equipment and economic losses. This paper presents the verification analysis of power quality signals classification system. The developed system is based on linear time-frequency distribution (TFD) which is spectrogram that represents the signals jointly in time-frequency representation (TFR). The TFD is very appropriate to analyze power quality signals that have magnitude and frequency variations. Parameters of the signal such as root mean square (RMS) and fundamental RMS, total waveform distortion (TWD), total harmonic distortion (THD) and total non-harmonic distortion (TnHD) of voltage signal are estimated from the TFR to identify the characteristics of the signal. Then, the signal characteristics are used as input for signal classifier to classify power quality signals. In addition, standard power line measurements are also calculated from voltage and current such as RMS and fundamental RMS voltage and current, real power, apparent power, reactive power, frequency and power factor. The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std. 1159-2009. The power quality analysis has been tested using a set of data and the results show that, the spectrogram gives high accuracy measurement of signal characteristics. However, the system offers lower accuracy compare to simulation due to the limitation of the system.
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Ha, IlKyu, Zhehao Zhang, HeeJoo Park, and ChongGun Kim. "Analysis of Wi-Fi Signal Characteristics for Indoor Positioning Measurement." Journal of the Korean Institute of Information and Communication Engineering 16, no. 10 (October 31, 2012): 2177–84. http://dx.doi.org/10.6109/jkiice.2012.16.10.2177.
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AOSHIMA, Nobuharu. "Measurement of Flow Control System Characteristics by Signal Compression Method." Transactions of the Society of Instrument and Control Engineers 22, no. 12 (1986): 1298–304. http://dx.doi.org/10.9746/sicetr1965.22.1298.
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Koropchak, John A., and D. H. Winn. "Fundamental Characteristics of Thermospray Aerosols and Sample Introduction for Atomic Spectrometry." Applied Spectroscopy 41, no. 8 (November 1987): 1311–18. http://dx.doi.org/10.1366/0003702874447338.
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Sample introduction to inductively coupled plasma atomic emission using thermospray nebulization is studied at a fundamental level. Optimum signals and signal-to-noise ratios result from thermospray operation at temperatures which coincide with highest analyte transport (>20%). High transport levels are maintained at sample flow rates of up to 3 mL/min. On the basis of comparison with analyte transport measurements for a pneumatic nebulizer (1.5%), signal increases are less than anticipated. Measurement of primary thermospray aerosols, using Fraunhofer diffraction, indicates that the enhanced transport results from decreased particle sizes for thermospray aerosols compared with pneumatic aerosols. Solvent is more rapidly vaporized from hot thermospray aerosols, further increasing the disparity in particle sizes. On the basis of aerosol particle size data, a conceptual model for aerosol generation, which is similar to pneumatic processes, is developed for thermospray. Trends for further improvements in thermospray aerosol production are predicted.
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Передерко А.Л., к.т.н. "SIGNAL PHASE SHIFTS DURING THE MEASUREMENT OF VIBRATION PARAMETERS." Перспективні технології та прилади, no. 16 (August 31, 2020): 100–104. http://dx.doi.org/10.36910/6775-2313-5352-2020-16-13.
Повний текст джерелаАнотація:
In systems of vibration control, monitoring, diagnostics, active vibration protection, measurements and control of vibration parameters are necessary. For this, piezoelectric sensors are widely used in them as primary transducers. These sensors, due to their high metrological characteristics, such as accuracy, speed, a wide band of operating frequencies and temperatures, are traditionally used to measure vibration displacement, vibration velocity and vibration acceleration. The use of these types of sensors is necessary due to the need to measure and control vibration at objects with different frequency characteristics. The article considers possible distortions of the measured signal at the output of the sensors due to phase shifts. These phase shifts must be taken into account when developing and constructing measurement and processing schemes of the vibration signal. This is especially true when measuring and recording a rapid vibration processes, such as mechanical shock.
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Zhang, Anan, Cong He, Maoyi Sun, Qian Li, Hong Wei Li, and Lin Yang. "Partial discharge signal self-adaptive sparse decomposition noise abatement based on spectral kurtosis and S-transform." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 1 (January 2, 2018): 293–306. http://dx.doi.org/10.1108/compel-03-2017-0126.
Повний текст джерелаАнотація:
Purpose Noise abatement is one of the key techniques for Partial Discharge (PD) on-line measurement and monitoring. However, how to enhance the efficiency of PD signal noise suppression is a challenging work. Hence, this study aims to improve the efficiency of PD signal noise abatement. Design/methodology/approach In this approach, the time–frequency characteristics of PD signal had been obtained based on fast kurtogram and S-transform time–frequency spectrum, and these characteristics were used to optimize the parameters for the signal matching over-complete dictionary. Subsequently, a self-adaptive selection of matching atoms was realized when using Matching Pursuit (MP) to analyze PD signals, which leading to seldom noise signal element was represented in sparse decomposition. Findings The de-noising of PD signals was achieved efficiently. Simulation and experimental results show that the proposed method has good adaptability and significant noise abatement effect compared with Empirical Mode Decomposition, Wavelet Threshold and global signal sparse decomposition of MP. Originality/value A self-adaptive noise abatement method was proposed to improve the efficiency of PD signal noise suppression based on the signal sparse representation and its MP algorithm, which is significant to on-line PD measurement.
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Liu, Ke, Wenqi Wu, Kanghua Tang, and Lei He. "IMU Signal Generator Based on Dual Quaternion Interpolation for Integration Simulation." Sensors 18, no. 8 (August 18, 2018): 2721. http://dx.doi.org/10.3390/s18082721.
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This paper focuses on the problem of high-update-rate and high accuracy inertial measurement unit signal generation. In order to be in accordance with the vehicle’s kinematic and dynamic characteristics as well as the characteristics of pseudorange of post-processed global navigation satellite system and their rate measurements, a novel dual quaternion interpolation and analytic integration algorithm based on actual flight data is proposed. The proposed method can simplify the piecewise analytical expressions of angular rates, angular increments and specific force integral increments. Norm corrections are adopted as constraint conditions to guarantee the accuracy of the signals. Numerical simulations are conducted to validate the method’s performance.
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Zhou, Hongming, Peiyuan Li, Longfei Wu, and Qiankun Gao. "A wavelet analysis-based matching pursuit algorithm for an accurate ultrasonic TOFD measurement." Insight - Non-Destructive Testing and Condition Monitoring 62, no. 11 (November 1, 2020): 662–68. http://dx.doi.org/10.1784/insi.2020.62.11.662.
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The time-of-flight diffraction (TOFD) technique is used as an important non-destructive testing method in weld integrity evaluation and failure analysis. However, an accurate measurement of the time-of-flight (TOF) has proven to be difficult due to the low time resolution of the measured signal. Conventional deconvolution techniques have been used to improve the time resolution of the signal but are not effective for ultrasonic TOFD signals because the frequency contents of the signals are non-static in space-frequency distribution. To overcome this problem, a method is proposed in this paper that estimates the TOF in two steps. In the first step, the measured signal is decomposed into a series of narrowband signals using a wavelet transform and an atom dictionary is adaptively established according to the characteristics of a selected narrowband signal. In the second step, matching pursuit (MP) is used to derive a sparse representation of the selected narrowband signal. A steel specimen with artificial defects is prepared, experiments are carried out and the results confirm the efficacy of the proposed algorithm.
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Lysenko, Iuliia, Volodymyr Eremenko, Yurii Kuts, Anatoliy Protasov, and Valentin Uchanin. "Advanced Signal Processing Methods for Inspection of Aircraft Structural Materials." Transactions on Aerospace Research 2020, no. 2 (June 1, 2020): 27–35. http://dx.doi.org/10.2478/tar-2020-0008.
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AbstractAircraft, their assemblies, and units must provide high durability and reliability, and maintain mechanical and technological characteristics throughout the life span of the aircraft. Different elements of aircraft structures work under mechanical loads, over a wide temperature range, with varying degrees of exposure to corrosive environments. Aircraft structural materials have a variation in the characteristics values and require the various testing methods for their inspection.In many NDT methods applied in aviation materials testing, signals that could be represented by a narrowband processes model are used. Known methods of their processing are focused on determining and analyzing the signals amplitude characteristics, but the information resource contained in phase characteristics is not used.In the article, the methodology for signal processing and determining phase characteristics in the time domain are discussed. It is based on the combination of the discrete Hilbert transform and the deterministic and statistical methods of the phase measurement. There are given examples of the application of the methodology for pulsed eddy current testing of electrically conductive materials and products, ultrasonic thickness measurement of products made of materials have significant ultrasonic attenuation, the realization impulse variant of acoustic impedance flaw detection of products made of composite materials. The examples have shown that the proposed signal processing methodology enables to determine new information parameters and signal characteristics for the industry, and extend the scope of known NDT methods.
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Dwi Jaya Putra, IGN Agung, D. M. Wiharta, and N. P. Sastra. "ANALISIS JARINGAN WLAN 802.11g RUMAH SAKIT KAPAL KABUPATEN BADUNG." Jurnal SPEKTRUM 5, no. 2 (December 18, 2018): 200. http://dx.doi.org/10.24843/spektrum.2018.v05.i02.p25.
Повний текст джерелаАнотація:
For direct testing sometimes the signal level of the access point cannot always cover the maximum range of distance due to signal wave propagation in the room, such as reflection, alteration, or scattering of signals. For the purpose of implementation optimization, this study aims to obtain characteristics of signal level quality and QoS at the Mangusada Hospital of Badung Regency. The indoor propagation analysis of WLAN IEEE 802.11g is based on 3 models of measurement ie without barrier, wall barrier, and floor barrier. The result of the highest signal level measurement is -49 dBm, while the lowest signal level is -88 dBm. Maximum throughput measurement results 8.05 Mbps, from the maximum available bandwidth of 10 Mbps. While the coverage area based on testers using the software to adjust the floor plan on the building, almost in accordance with the calculation of signal level.
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Jin, Xiang Yang, and Shi Sheng Zhong. "The Order Tracking Study of Variant Speed Process of Aeroengine Vibration Signal." Key Engineering Materials 419-420 (October 2009): 805–8. http://dx.doi.org/10.4028/www.scientific.net/kem.419-420.805.
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Order tracking is an important method to analyze the response characteristics of rotating machinery for fault diagnosis and condition monitoring in rotating machinery. Order tracking method overcomes the shortcomings of traditional resampling and FFT method. A new use based on the order tracking analysis is proposed in this paper, the computed order tracking method is applied to analyse the dynamic vibration signals during aeroengine start-stop process.In the aeroengine test, the fault characteristic of rotating shafts is related to the rotating speed,vibration will be more complicated and diversified with the increasing speed during run-up process, and has characteristics of periodicity and multiple frequency. It is of vital critical to extract characteristic information from exterior measurement vibration signal and get interior fault information. Applying the order tracking in the analysis of aeroengine signals shows that it can extract the fault characteristics and realize the state monitoring.
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Shi, Bo, Fan Zhang, Fanlin Yang, Yanquan Lyu, Shun Zhang, and Guoyu Li. "A Positioning Error Compensation Method for a Mobile Measurement System Based on Plane Control." Sensors 20, no. 1 (January 4, 2020): 294. http://dx.doi.org/10.3390/s20010294.
Повний текст джерелаАнотація:
Global navigation satellite system (GNSS)/inertial navigation system (INS) navigation technology is one of the core technologies in a mobile measurement system and can provide real-time geo-referenced information. However, in the environment measurements, buildings cover up the GNSS signal, causing satellite signals to experience loss-of-lock. At this time errors of INS independent navigation accumulate rapidly, so it cannot meet the needs of the mobile measurement system. In this paper, a positioning error compensation method based on plane control is proposed by analyzing the error characteristics of position and orientation caused by satellite signal loss-of-lock in the urban environment. This method control uses planar features and the laser point cloud positioning equation to establish an adjustment model that ignores the influence of the attitude error and finds the positioning error at the middle point of the GNSS signal loss-of-lock time period, and then compensates for the error at other points by using the characteristics of the positioning error. The experimental results show that the accuracy of the compensated laser point cloud has been significantly improved, and the feasibility of the method is verified. Meanwhile, the method can rely on the existing building plane so the method is adaptable and easy to implement.
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BARAS, S., L. KRUPELNITSKYI, and O. ONYSCHUK. "MEASUREMENT OF NARROWBAND RESISTANCE FREQUENCY RADIO SIGNAL OF LIMITED DURATION." HERALD OF KHMELNYTSKYI NATIONAL UNIVERSITY 295, no. 2 (May 2021): 56–63. http://dx.doi.org/10.31891/2307-5732-2021-295-2-56-63.
Повний текст джерелаАнотація:
The work concerns analog-digital systems that work with radio signals emitted and received by the antenna, and these signals have a limited duration, ie are pulsed. The propagation conditions of such signals and the processes of formation of echo signals affect their amplitude, frequency and phase characteristics in such a way that they form classical narrowband signals. The operation of the system involves the determination of certain parameters of echo signals, and taking into account their pulse nature for such a definition is given a limited time interval. This means that the procedure for determining the parameters must meet the criterion of high speed, and therefore differ from the traditional, built on the use of phase-locked loop. The article is devoted to solving the problem of measuring the reference frequency of a pulsed narrowband radio signal. By analyzing the results of experimental studies, two types of errors in measuring the reference frequency of a narrowband radio signal were identified and the causes of their occurrence were established. These errors are provoked by the peculiarities of the structure of the narrowband signal. The reason for the error of the 1st type, the absolute value of which correlates with the duration of the half-cycle of the reference frequency, is the so-called phase jumps at the point of change of the sign of the bypass. The frequency of such errors within the duration of the echo signal is generally low, although it increases with increasing signal spectrum width. Type 2 errors occur due to the appearance of zones with almost completely suppressed signal amplitude, which may be the result of intrapulse interference and / or signal attenuation. Such errors also occur more often if the spectrum width is larger. A method for measuring the reference frequency of a narrowband pulsed radio signal is proposed, which is based on counting the number of half-cycles of the reference frequency on a time-limited measurement interval and removing from this procedure areas with completely suppressed signal amplitude. An auxiliary highly stable reference frequency is used to establish the numerical value of the reference frequency. The block diagram of the frequency meter and the algorithm of its operation are given, the implementation of which avoids these errors.
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Moore, James H., C. W. Bray, S. T. Griffin, P. D. Mixon, and J. C. Williams. "High-Voltage Monitor for Measuring Electrical Characteristics of Pulsed Hollow Cathode Discharges." Applied Spectroscopy 48, no. 10 (October 1994): 1204–7. http://dx.doi.org/10.1366/0003702944027354.
Повний текст джерелаАнотація:
A high-voltage monitor has been developed for measuring small signal differences between large voltage waveforms. This device reduces the number of channels needed for a differential measurement from two to one while maximizing the performance of an oscilloscope by removing large common-mode signals present in typical discharge applications.
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Shakiryanov, Insaf I., Sait A. Bakhteev, Svetlana G. Smerdova, Artem S. Maltsev, and Rafail A. Yusupov. "Integrated analysis system for laser emition spectrum to ensure quality measurements." Butlerov Communications 64, no. 11 (November 30, 2020): 83–87. http://dx.doi.org/10.37952/roi-jbc-01/20-64-11-83.
Повний текст джерелаАнотація:
To ensure the reliability of calculations of the parameters of the spectra obtained by various methods, a program was created for decomposing the spectra into Gaussian components in manual and automatic modes. Manual mode is used to determine the boundary conditions necessary for determining the global extremum. Next, an automatic mode is launched that provides rapid calculations of the spectrum parameters and determines their metrological characteristics, separating the value of the useful signal from the signals of the components, background and noise. The paper shows examples of separating the chromium signal from the signals of the components located on the right and left, as well as from the background signal and taking into account the noise level, which allows improving the analysis characteristics. Optimization of the program in order to determine the boundary parameters of the search for calculated parameters and its robustness is debugged by creating data similar to the experimental data using the "folding knife" or "BUTSTRAP" method.. Measurement quality is ensured by integrating experimental data with the capabilities of the SPECTRUM program. The SPECTRUM program is used as a database for metrological support of measurements and determination of reliability, expressiveness and cost-effectiveness of measurements. In examples 11 parameters: S1, S2, S3, M1, M2, M3, σ1, σ2, σ3, A, where S2 – the area of the useful signal; S1, S3 square harmful signals; M1, M2, M3 – wavelength signals; σ1, σ2, σ3 – half-width signals; A, B – parameters of background; I – noise level. Useful S2 signals depending on the chromium concentration are the basis for determining the calibration function and determining the metrological characteristics of both the calibration function and the analysis result.
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Ye, Jie, Yanwei Liu, Zhihao Liang, Huibin Lin, and Kegang Zhao. "Measurement method of torsional vibration signal to extract gear meshing characteristics." Journal of Vibroengineering 20, no. 2 (March 31, 2018): 1007–20. http://dx.doi.org/10.21595/jve.2018.18906.
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Li, Guang Hui, Zheng Pei, Ran Chen, and Da Li Hu. "The Principal Component Analysis of Signal Characteristic Parameters." Applied Mechanics and Materials 128-129 (October 2011): 1269–72. http://dx.doi.org/10.4028/www.scientific.net/amm.128-129.1269.
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With the development of wireless communication, the automatic modulation recognition technology of communicational signals becomes an important theme. In this paper, based on multivariate statistical principal component analysis, we select characteristics of the signal, and use radio monitoring equipment mined measurement data to do some processing and analysis, which provided technical support to automatic modulation recognition of the radio signal.
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Ryan, Samuel, Emidio Pacecca, Jye Tebble, Joel Hocking, Thomas Kempton, and Aaron J. Coutts. "Measurement Characteristics of Athlete Monitoring Tools in Professional Australian Football." International Journal of Sports Physiology and Performance 15, no. 4 (April 1, 2020): 457–63. http://dx.doi.org/10.1123/ijspp.2019-0060.
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Purpose: To examine the measurement reliability and sensitivity of common athlete monitoring tools in professional Australian Football players. Methods: Test–retest reliability (noise) and weekly variation (signal) data were collected from 42 professional Australian footballers from 1 club during a competition season. Perceptual wellness was measured via questionnaires completed before main training sessions (48, 72, and 96 h postmatch), with players providing a rating (1–5 Likert scale) regarding their muscle soreness, sleep quality, fatigue level, stress, and motivation. Eccentric hamstring force and countermovement jumps were assessed via proprietary systems once per week. Heart rate recovery was assessed via a standard submaximal run test on a grass-covered field with players wearing a heart rate monitor. The heart rate recovery was calculated by subtracting average heart rate during final 10 seconds of rest from average heart rate during final 30 seconds of exercise. Typical test error was reported as coefficient of variation percentage (CV%) and intraclass coefficients. Sensitivity was calculated by dividing weekly CV% by test CV% to produce a signal to noise ratio. Results: All measures displayed acceptable sensitivity. Signal to noise ratio ranged from 1.3 to 11.1. Intraclass coefficients ranged from .30 to .97 for all measures. Conclusions: The heart rate recovery test, countermovement jump test, eccentric hamstring force test, and perceptual wellness all possess acceptable measurement sensitivity. Signal to noise ratio analysis is a novel method of assessing measurement characteristics of monitoring tools. These data can be used by coaches and scientists to identify meaningful changes in common measures of fitness and fatigue in professional Australian football.
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Indra Prasetya, AAN Agung, N. Gunantara, and P. K. Sudiarta. "ANALISIS PROPAGASI INDOOR WLAN 802.11g PADA GEDUNG DISHUBKOMINFO KABUPATEN BADUNG." Jurnal SPEKTRUM 4, no. 2 (January 8, 2018): 130. http://dx.doi.org/10.24843/spektrum.2017.v04.i02.p17.
Повний текст джерелаАнотація:
In practice the access point can not always cover the maximum range of distance due to signal wave propagation in the room, such as reflection, alteration, or scattering of signals. For the purpose of implementation optimization, this study aims to obtain characteristics of signal level quality and throughput at the Dishubkominfo Building of Badung Regency. The indoor propagation analysis of WLAN IEEE 802.11g is based on 3 models of measurement ie without barrier, wall barrier, and floor barrier. The result of the highest signal level measurement is -40 dBm, while the lowest signal level is -85 dBm. Maximum throughput measurement results 8.05 Mbps, from the maximum available bandwidth of 10 Mbps. While the coverage area based on testers using the software to adjust the floor plan on the building, almost in accordance with the calculation of signal level.
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Baba, Toshimitsu, Kazuhiro Ogawa, and Tetsuo Shoji. "Development of Novel Non-Destructive Inspection Technique Using High-Frequency Signal Transmission Characteristics." Key Engineering Materials 261-263 (April 2004): 949–54. http://dx.doi.org/10.4028/www.scientific.net/kem.261-263.949.
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A novel non-destructive inspection (NDI) technique that utilizes high-frequency signal transmission characteristics was developed as a more reliable, faster and cheaper NDI technique. This technique forms a transmission circuit that includes the specimen, and detects the signals generated by any surface breaking-defect. In this research, quantitative measurement of closed fatigue cracks was implemented via a newly developed probe. The greatest advantage of this technique is that there is no significant difference in detection of defects in either paramagnetic materials or in ferromagnetic materials. Therefore, the potential effects of corrosion, ferrite content, or deformation martensite on the measurement signals are minimized, and a better S/N ratio can be expected. This technique can also be used to measure the size of defects in components, including welded components, and its detection sensitivity is less than 1 mm for surface breaking-defects.
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Li, Yuxing, Xiao Chen, Jing Yu, and Xiaohui Yang. "A Fusion Frequency Feature Extraction Method for Underwater Acoustic Signal Based on Variational Mode Decomposition, Duffing Chaotic Oscillator and a Kind of Permutation Entropy." Electronics 8, no. 1 (January 5, 2019): 61. http://dx.doi.org/10.3390/electronics8010061.
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In order to effectively extract the frequency characteristics of an underwater acoustic signal under sensor measurement, a fusion frequency feature extraction method for an underwater acoustic signal is presented based on variational mode decomposition (VMD), duffing chaotic oscillator (DCO) and a kind of permutation entropy (PE). Firstly, VMD decomposes the complex multi-component underwater acoustic signal into a set of intrinsic mode functions (IMFs), so as to extract the estimated center frequency of each IMF. Secondly, the frequency of the line spectrum can be obtained by using DCO and a kind of PE (KPE). DCO is used to detect the actual frequency of the line spectrum for each IMF and KPE can determine the accurate frequency when the phase space track is in the great periodic state. Finally, the frequency characteristic parameters acted as the input of the support vector machine (SVM) to distinguish different types of underwater acoustic signals. By comparing with the other three traditional methods for simulation signal and different kinds of underwater acoustic signals, the results show that the proposed method can accurately extract the frequency characteristics and effectively realize the classification and recognition for the underwater acoustic signal.
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Tyshko, S., O. Lavrut, V. Smolar, O. Zabula, and Yu Chernichenko. "Application of spectral analysis for determine the phase shift of signals with equal amplitudes using full-wave transformation when measuring the characteristics of weapons." Military Technical Collection, no. 25 (December 8, 2021): 12–23. http://dx.doi.org/10.33577/2312-4458.25.2021.12-23.
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The article defines the list of technical characteristics of armaments and military equipment (ARM), the value of which is measured using phase methods. An analysis of known methods that have found wide application in measuring technology, which is designed to determine the technical characteristics associated with the measurement of phase shift during the development, manufacture and operation of weapons. Based on this analysis, it was determined that the measuring systems are designed to determine the phase shift of two harmonic signals in their composition have two channels of information transmission. This architecture of the implementation of measuring systems leads to the fact that a significant impact on the accuracy of the proposed measurement problem, makes a component of the error due to the phase symmetry of the signal transmission channels, as well as internal and external noise. As an alternative approach to solving the measurement problem of determining the phase shift of two harmonic signals, which will significantly reduce the error component due to phase asymmetry of information transmission channels, it is proposed to use the signal obtained by summing harmonic signals after full-wave transformation followed by spectral analysis. In order to implement the above approach, a measurement problem was set to determine the phase shift of two harmonic signals, using spectral analysis of the signal obtained by summing the harmonic signals after their full-wave transformation. A list of assumptions required for the synthesis of analytical relations that establish the relationship between the spectra of phases and amplitudes (power) of the signal obtained by summing harmonic signals after their full-wave transformation and phase shift of two harmonic signals. Analytical relationships are proposed that establish the relationship between the above characteristics. It is shown that the values of the spectrum of phases and amplitudes, which are calculated using the proposed expressions, differ from the values obtained in the calculations using the Fourier series coefficients, not more than 0.1%.
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Liu, Xiaohan, Guangfeng Shi, and Weina Liu. "An Improved Empirical Mode Decomposition Method for Vibration Signal." Wireless Communications and Mobile Computing 2021 (April 27, 2021): 1–8. http://dx.doi.org/10.1155/2021/5525270.
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With the development of electronic measurement and signal processing technology, nonstationary and nonlinear signal characteristics are widely used in the fields of error diagnosis, system recognition, and biomedical instruments. Whether these features can be extracted effectively usually affects the performance of the entire system. Based on the above background, the research purpose of this paper is an improved vibration empirical mode decomposition method. This article introduces a method of blasting vibration signal processing—Differential Empirical Mode Decomposition (DEMD), combined with phosphate rock engineering blasting vibration monitoring test, and Empirical Mode Decomposition (EMD) to compare and analyze the frequency screening of blasting vibration signals, the aliasing distortion, and the power spectrum characteristics of the decomposed signal. The results show that compared with EMD, DEMD effectively suppresses signal aliasing and distortion, and from the characteristics of signal power spectrum changes, DEMD extracts different dominant frequency components, and the frequency screening effect of blasting vibration signals is superior to EMD. It can bring about an obvious improvement in accuracy, and the calculation time is about 4 times that of the EMD method. Based on the ground analysis of ground motion signals, this paper uses the EMD algorithm to analyze measured ground blast motion signals and study its velocity characteristics and differential time, which provides a new way of studying motion signals.
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Du, Gang, Weikui Wang, Shizhe Song, and Shijiu Jin. "Detection of corrosion on 304 stainless steel by acoustic emission measurement." Anti-Corrosion Methods and Materials 57, no. 3 (May 25, 2010): 126–32. http://dx.doi.org/10.1108/00035591011040083.
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PurposeThe purpose of this paper is to report an investigation of the acoustic emission (AE) characteristics of the corrosion process of 304 stainless steel in acidic NaCl solution.Design/methodology/approachThe corrosion behavior of a specimen with constant load in acidic NaCl solution was studied, and the AE signal characteristics of the corrosion process were analyzed. Stress corrosion cracking of the specimen was detected using the AE and electrochemical noise (EN) techniques, and the acquired data were compared.FindingsThe results indicated that AE technology is very sensitive to the AE signals generated by 304 nitrogen controlled stainless steel in acidic NaCl solution. The characteristics of AE signals at different stages of the corrosion process are significantly different. Additionally, the AE test result is confirmed by the EN test results.Originality/valueThe characteristics of AE signals at different stages of the corrosion process are gained for the first time, which is an important guide by which to distinguishing different stages of corrosion.
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Hu, Zheng Bang, Xia Lun Yun, Ge Dong Jiang, Chang Jianig Chen, and Xue Song Mei. "Non-Stationary Signal Purification and Rotor Axis Orbit Feature Extraction under Machine Tool Spindle Cutting Process." Applied Mechanics and Materials 868 (July 2017): 305–10. http://dx.doi.org/10.4028/www.scientific.net/amm.868.305.
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Rotor axis orbit measurement of the spindle under cutting process is the important basis of cutting quality judgment and spindle fault diagnosis. In the cutting process, the non-stationary characteristics of vibration measurement signal of spindle rotor has been particularly outstanding, under such circumstances it is difficult to draw spindle rotor axis orbit accurately. To solve this problem, a new method using EEMD (Ensemble Empirical Mode Decomposition) and harmonic wavelet is put forward to realize non-stationary signal purification and rotor axis orbit feature extraction under machine tool spindle cutting process. In order to filter out the high frequency noise of the measurement, the EEMD method has been used, in addition that the characteristics of the original signal is preserved well. However the signal after EEMD filter still contains a variety of frequency components, in order to solve it, the harmonic wavelet method is used to decompose the signal into several signals according to the different frequency components, through the signal reconstruction achieve rotor axis orbit feature extraction. Using this method, the machined workpiece has been cut under the speed of 12000r/min, the vibration of spindle has been measured and processed. The experiment results show that the new method can effectively reduce the high frequency interference noise signal, and also apparently the rotor axis orbit obtained is more clearly than the original rotor axis orbit.
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Tian, Tian, Wu Jian, and Nie Li. "Measurement of Amplifier Open-Loop Amplitude Frequency Characteristics Based on Virtual Instrument." Applied Mechanics and Materials 475-476 (December 2013): 16–22. http://dx.doi.org/10.4028/www.scientific.net/amm.475-476.16.
Повний текст джерелаАнотація:
In the electronic measurement field, how to measure the open-loop amplitude frequency characteristics of the amplifier automatically is a question to be overcame. And now , the system ,which under the integrated development environment that the virtual instrument software LabVIEW provides, to measure the open-loop amplitude frequency characteristics of the amplifier is developed by combining the modern electronic measurement technology and computer data processing technology. The virtual signal generator which is based on the data acquisition card, signal acquisition, correlation analysis, frequency response analysis, etc is included in the system. This design mainly includes the hardware circuit and the software program. The hardware circuit consists of the low noise preamplifier, measured operational amplifier, data acquisition card, power supply, computer, etc. Modular design is adopted in the software part, which includes the design of soft panel, signal generation, collection and analysis module. The advantages of the virtual instrument, such as the digital signal processing, waveform data automatic storage, graphical programming, are fully used in the modern electronic measurement. Simple structure, low cost, high level of test automation are its characteristics.
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Li, Jun, Kai Ren, Hao Dong Chen, Hai Long Jiang, Chao Wang, and Tao Huang. "Characteristic Analysis of Downhole Pressure Signal while Drilling under Drillstring Washout Conditions." Materials Science Forum 944 (January 2019): 1040–49. http://dx.doi.org/10.4028/www.scientific.net/msf.944.1040.
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The identification of drillstring washout conditions during drilling is mostly based on standpipe pressure, drilling fluid flow rate or turbine RPM. These methods are inaccurate or not applicable to other drilling methods. It is difficult to find the drillstring washout conditions in time. While the downhole measurement technology can provide important informations for real-time discrimination of downhole conditions, there are few studies on the fluctuation characteristics of pressure signals while drilling under drillstring washout conditions. Using finite element software to simulate wellbore pressure distribution under drillstring washout conditions, Based on the self-developed near-bit multi-parameter measurement tool, the downhole drilling pressure signal is collected, and the signal density analysis method such as probability density, wavelet, spectrum and time domain is used to discuss the relationship between the fluctuation characteristics of the pressure signal while drilling and drillstring washout. The results show that, (1) Before and after washout occur, the pressure distribution inside and outside the drill string changed significantly. After washout occur, there is fluid outflow at the puncture, and the fluid flow velocity in the drill string and the annulus at the bottomhole decrease,the pressure in the drillstring and the annulus smaller than before the puncture. (2) The time domain and frequency domain characteristics of pressure while drilling can judge the occurrence of the drillstring washout. When washout occurs, the annulus pressure near the drill bit drops sharply, and the pressure signal spectrum produces a low frequency band. (3) The wavelet analysis and probability density characteristics of the pressure while drilling can be used as an auxiliary basis for the drillstring washout. The wavelet detail signal of the pressure signal can judge the pressure fluctuation, and the probability density characteristic can judge the change of the pressure amplitude. The fluctuation characteristics of the drilling pressure signal under drillstring washout obtained in this paper can provide reference and guidance for the identification of complex conditions in the drilling process.
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Dmitriev, D. V., and V. S. Polishkarov. "Formation of the Sounding Signal of an Orbital Radio Altimeter." Rocket-space device engineering and information systems 9, no. 1 (2022): 67–72. http://dx.doi.org/10.30894/issn2409-0239.2022.9.1.67.72.
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The accuracy of the formation of sounding signals of quasi-continuous radars is determined by the requirements for the permissible instrumental component of the error in measuring of the distance and Doppler frequency shift. High-precision orbital radio altimeters, as a rule, use precision signals with linear frequency modulation (chirp signals) as sounding signals, the linearity characteristics of which are quite demanding, since deviations from the linear law of change in the frequency of the radio altimeter sounding signal cause additional measurement errors. To reduce the instrumental error of the radio altimeter, it is necessary to improve the quality of the formation of the probing chirp signal, which can be ensured by forming them digitally. To assess the possibility of using a synthesizer based on the 1508PL8T microcircuit as a generator of the probing signal of a radio altimeter, measurements of the frequency modulation linearity were performed. The linearity of the modulation was estimated by the deviation of the instantaneous phase of the synthesized signal from the quadratic dependence. Studies have shown that fast fluctuations of the chirp signal frequency are significantly influenced by the time it takes the synthesizer to change the rate of rise of the signal phase. The selection of the parameters of the synthesized signals and the characteristics of the filters at the output of the digital-to-analog converters made it possible to reduce the formation error to 2.9·10−3 rad (RMS). When choosing the type of integrated synthesizer, it is necessary to focus on microcircuits with a high DAC clock frequency (above 1 GHz) and a short time spent on changing the output signal frequency (no more than 4 clock periods).
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Guo, Qing, Xingjian Wang, and Cuifeng Xu. "Design of high precision angle measuring instrument based on Kalman filter." Journal of Physics: Conference Series 2183, no. 1 (January 1, 2022): 012004. http://dx.doi.org/10.1088/1742-6596/2183/1/012004.
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Abstract Angle parameters are common parameters in production and life. The main process is converting the inclination signal into other signals for measurement. In order to overcome the problems of low-cost, long-term, and high-precision angle detection that traditional angle measurement systems cannot solve, a high-precision, low-cost, and small-size angle measurement system is designed. The high-precision angle sensor signal used in this paper is based on MEMS angle sensor. The angle sensor has the characteristics of extremely low temperature dependence, low noise and high resolution. In terms of hardware, various methods are used on the circuit board to eliminate noise during signal transmission. These methods are used to improve the accuracy of the angle measurement system. The Kalman filter algorithm is used to filter out noise to reduce the influence of noise on high-precision angle signals in terms of software. Experiments on the system show that the accuracy of the angle measurement system reaches 0.0014°, which achieve the goal of system design, can solve the problem of long-term, high-precision angle measurement, and completes the system design.
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Sun, Wei, Hiroya Ohta, Taku Ninomiya, Yasunori Goto, and Yasunari Sohta. "Depth-correlated backscattered electron signal intensity for 3D-profile measurement of high aspect ratio holes." Microscopy 68, no. 5 (August 6, 2019): 385–94. http://dx.doi.org/10.1093/jmicro/dfz026.
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Abstract In-line metrology for measuring 3D features of the high aspect ratio (HAR) holes is becoming more challenging due to the progressing semiconductor technology, particularly in memory devices. Measurements of the bottom critical dimension (CD), taper angles and 3D profiles of the HAR holes require new imaging capabilities. In this work, we explored the characteristics of high-energy backscattered electron (BSE) signals and demonstrated their promising application to 3D metrology. From Monte Carlo simulation results, it is worth noting that BSE signal intensity emitted from an irradiated location in the depth of the hole decreases exponentially with the increase of the depth from the top surface (perpendicular depth) of the hole. Furthermore, the influences of various factors including the electron energy, the depth and the sidewall angle (SWA) of the hole on the attenuation of the BSE signal intensity were investigated. The simulation results show that the attenuation of the BSE signal intensity depends on the electron energy, the depth and the density of the hole but is independent of the SWA and the incident angle of the primary electron beam. Based on the characteristics of the BSE signal intensity, an algorithm was proposed for the 3D metrology of the HAR holes. Finally, the differences in CDs between the measured value and the target value of HAR holes with various geometries were examined. A maximum measurement bias within ±2.0 nm for various holes with different depths, densities and SWA values shows great potential of depth-correlated BSE signals in 3D metrology.
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Noda, Toshihiko, Hidekuni Takao, Mitsuaki Ashiki, Hiroyuki Ebi, Kazuaki Sawada, and Makoto Ishida. "Characteristics of High-Resolution Hemoglobin Measurement Microchip Integrated with Signal Processing Circuit." Japanese Journal of Applied Physics 43, no. 4B (April 27, 2004): 2392–96. http://dx.doi.org/10.1143/jjap.43.2392.
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Özdamar, Özcan, and Rafael E. Delgado. "Measurement of signal and noise characteristics in ongoing auditory brainstem response averaging." Annals of Biomedical Engineering 24, no. 6 (November 1996): 702–15. http://dx.doi.org/10.1007/bf02684183.
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Yang, Jing Gang, Yong Yong Jia, Zhi Cheng Zhou, and Jun Hao Li. "The Measurement System of Partial Discharge under Impulse Voltage." Applied Mechanics and Materials 543-547 (March 2014): 1046–49. http://dx.doi.org/10.4028/www.scientific.net/amm.543-547.1046.
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Partial discharge (PD) is the important detection parameter for power equipment, with the development of high voltage test technology, PD detection under impulse voltage is more attention. In order to detect the partial discharge signal under the impulse voltage, this paper designs a high-frequency current sensor and broadband measurement impedance. A set of partial discharge measurement system under impulse voltage is built up. The frequency characteristics of current sensor and measurement impedance are detected. In order to test the measurement system, the PD signals of a needle defect under impulse voltage is detected, the test results show that the PD measurement system can detect the PD signals effectively.