Definition of the best prediction criteria of the time domain signal-averaged electrocardiogram for serious arryhthmic events in the postinfarction period

For the fuzziness of the fault symptoms in motor rotor, this paper proposes a fault diagnostic method which based on the time-domain statistical features and the fuzzy c-means clustering analysis (FCM). This method is to extract the characteristic features of time-domain signal via time-domain statistics and to import the extracted characteristic vector to classifier. And then the fuzzy c-means realizes the classification by confirming the distance among samples, which is based on the degree of membership between the sample and the clustering center. The fault diagnostic cases of motor rotor show that the method which bases on the time-domain statistical features-FCM can detect the rotor fault effectively and distinguish the different types of fault correctly. Therefore, it can be used as an important means of rotor fault identification.

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Ultrawideband Impulse Radar Through-the-Wall Imaging with Compressive Sensing

International Journal of Antennas and Propagation ◽

10.1155/2012/251497 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 34

Author(s):

Wenji Zhang ◽

Moeness G. Amin ◽

Fauzia Ahmad ◽

Ahmad Hoorfar ◽

Graeme E. Smith

Keyword(s):

Compressive Sensing ◽

Time Domain ◽

Measurement Data ◽

Acquisition Time ◽

Time Domain Signal ◽

Spatially Extended ◽

Data Volume ◽

Order Of Magnitude ◽

New Perspective ◽

The Time Domain

Compressive Sensing (CS) provides a new perspective for addressing radar applications requiring large amount of measurements and long data acquisition time; both issues are inherent in through-the-wall radar imaging (TWRI). Most CS techniques applied to TWRI consider stepped-frequency radar platforms. In this paper, the impulse radar two-dimensional (2D) TWRI problem is cast within the framework of CS and solved by the sparse constraint optimization performed on time-domain samples. Instead of the direct sampling of the time domain signal at the Nyquist rate, the Random Modulation Preintegration architecture is employed for the CS projection measurement, which significantly reduces the amount of measurement data for TWRI. Numerical results for point-like and spatially extended targets show that high-quality reliable TWRI based on the CS imaging approach can be achieved with a number of data points with an order of magnitude less than that required by conventional beamforming using the entire data volume.

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Investigation of Light Parameters on Image Quality and Optical Coherence Tomography

International Journal of Optics ◽

10.1155/2021/2322858 ◽

2021 ◽

Vol 2021 ◽

pp. 1-6

Author(s):

Boka Fikadu ◽

Bulcha Bekele ◽

Leta Tesfaye Jule ◽

Anatol Degefa ◽

N. Nagaprasad ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Image Quality ◽

Time Domain ◽

Glass Sample ◽

Michelson Interferometer ◽

Signal Strength ◽

Optical Coherence ◽

Time Domain Signal ◽

Significant Difference ◽

The Time Domain

In this work, image quality and optical coherence tomography were studied. The results of the study show that there is a very significant difference between ultrasound and optical coherence tomography to produce an image with a different wave. To understand this, we studied the basic principle of optical coherence tomography in the Michelson interferometer using monochromatic and broadband sources. Time-domain and spectral-domain measurements, which exist at the detector level, are briefly described using a glass sample. The time-domain signal strength of the Michelson interferometer using a broadband source is a Gaussian envelope.

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Discrete Time, Discrete Frequency

10.1093/oso/9780197524015.003.0005 ◽

2021 ◽

pp. 106-155

Author(s):

Victor Lazzarini

Keyword(s):

Signal Processing ◽

Fourier Transform ◽

Discrete Time ◽

Time Domain ◽

Continuous Time ◽

Time Varying ◽

Discrete Frequency ◽

The Fourier Transform ◽

Definition Of ◽

The Time Domain

This chapter is dedicated to exploring a form of the Fourier transform that can be applied to digital waveforms, the discrete Fourier transform (DFT). The theory is introduced and discussed as a modification to the continuous-time transform, alongside the concept of windowing in the time domain. The fast Fourier transform is explored as an efficient algorithm for the computation of the DFT. The operation of discrete-time convolution is presented as a straight application of the DFT in musical signal processing. The chapter closes with a detailed look at time-varying convolution, which extends the principles developed earlier. The conclusion expands the definition of spectrum once more.

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Multiple Machine Learning Algorithms Comparison for Modulation Type Classification Based on Instantaneous Values of the Time Domain Signal and Time Series Statistics Derived from Wavelet Transform

Advances in Science Technology and Engineering Systems Journal ◽

10.25046/aj060172 ◽

2021 ◽

Vol 6 (1) ◽

pp. 658-671

Author(s):

Inna Valieva ◽

Iurii Voitenko ◽

Mats Björkman ◽

Johan Åkerberg ◽

Mikael Ekström

Keyword(s):

Machine Learning ◽

Time Series ◽

Wavelet Transform ◽

Time Domain ◽

Machine Learning Algorithms ◽

Time Domain Signal ◽

Modulation Type ◽

Instantaneous Values ◽

The Time Domain ◽

Type Classification

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Rolling Bearing Fault Diagnosis Research

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.155-156.87 ◽

2012 ◽

Vol 155-156 ◽

pp. 87-91

Author(s):

Zhong Hu Yuan ◽

Yang Su ◽

Xiao Xuan Qi

Keyword(s):

Fault Diagnosis ◽

Time Domain ◽

Recognition Rate ◽

Principal Component ◽

Rolling Bearing ◽

Bearing Fault ◽

Bearing Fault Diagnosis ◽

Time Domain Signal ◽

Feature Information ◽

The Time Domain

According to the characteristics of the rolling bearing fault, we make the research on fault diagnosis. Time domain signal can not perform the fault feature information well. The power spectrum changes the time domain signals into the frequency signals. It sets up the new data model. It uses the principal component analysis on fault diagnosis. It uses T square statistics and Q statistics methods to make fault diagnosis. Simulation experiment results demonstrate that this method provides a high recognition rate.

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Suspending the “Time Domain” : Technological Tempor(e)alities of Media Infrastructures

10.5117/9789463727426_ch04 ◽

2021 ◽

Author(s):

Wolfgang Ernst

Keyword(s):

Time Domain ◽

Time Function ◽

Archaeological Investigation ◽

Temporal Structures ◽

Definition Of ◽

The Time Domain ◽

Effects Of Media ◽

Media Event

Any media event is a time function of signals. In favor of a diagrammatic definition of technological media, media archaeological investigation is not only concerned with their structural “hardwired” level but with their operative unfolding-in-time as well. Such an understanding of techno-temporalities does not focus on phenomenal effects of media on humans but primarily refers to the microregimes within technological devices. In that sense, “hardwired temporality” refers to the infrastructuring of time by technologies and to temporal structures which are revealed from within techno-logical knowledge itself. From that arises an epistemology of technical processuality beyond the conventional notion of “time.”

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The Researches on Damage Detection Method for Truss Structures

E3S Web of Conferences ◽

10.1051/e3sconf/20183803030 ◽

2018 ◽

Vol 38 ◽

pp. 03030

Author(s):

Meng Hong Wang ◽

Xiao Nan Cao

Keyword(s):

Numerical Simulation ◽

Frequency Response ◽

Response Function ◽

Time Domain ◽

Experimental Analysis ◽

Frequency Response Function ◽

Principal Component ◽

Truss Structures ◽

Time Domain Signal ◽

The Time Domain

This paper presents an effective method to detect damage in truss structures. Numerical simulation and experimental analysis were carried out on a damaged truss structure under instantaneous excitation. The ideal excitation point and appropriate hammering method were determined to extract time domain signals under two working conditions. The frequency response function and principal component analysis were used for data processing, and the angle between the frequency response function vectors was selected as a damage index to ascertain the location of a damaged bar in the truss structure. In the numerical simulation, the time domain signal of all nodes was extracted to determine the location of the damaged bar. In the experimental analysis, the time domain signal of a portion of the nodes was extracted on the basis of an optimal sensor placement method based on the node strain energy coefficient. The results of the numerical simulation and experimental analysis showed that the damage detection method based on the frequency response function and principal component analysis could locate the damaged bar accurately.

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Cardiovascular control and time domain Granger causality: insights from selective autonomic blockade

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2012.0161 ◽

2013 ◽

Vol 371 (1997) ◽

pp. 20120161 ◽

Cited By ~ 34

Author(s):

Alberto Porta ◽

Paolo Castiglioni ◽

Marco Di Rienzo ◽

Tito Bassani ◽

Vlasta Bari ◽

...

Keyword(s):

Granger Causality ◽

Time Domain ◽

Closed Loop ◽

Systolic Arterial Pressure ◽

Cardiovascular Control ◽

Causal Direction ◽

Autonomic Blockade ◽

Definition Of ◽

The Time Domain ◽

Bidirectional Interactions

We studied causal relations among heart period (HP), systolic arterial pressure (SAP) and respiration (R) according to the definition of Granger causality in the time domain. Autonomic pharmacological challenges were used to alter the complexity of cardiovascular control. Atropine (AT), propranolol and clonidine (CL) were administered to block muscarinic receptors, β-adrenergic receptors and centrally sympathetic outflow, respectively. We found that: (i) at baseline, HP and SAP interacted in a closed loop with a dominant causal direction from HP to SAP; (ii) pharmacological blockades did not alter the bidirectional closed-loop interactions between HP and SAP, but AT reduced the dominance of the causal direction from HP to SAP; (iii) at baseline, bidirectional interactions between HP and R were frequently found; (iv) the closed-loop relation between HP and R was unmodified by the administration of drugs; (v) at baseline, unidirectional interactions from R to SAP were often found; and (vi) while AT induced frequently an uncoupling between R and SAP, CL favoured bidirectional interactions. These results prove that time domain measures of Granger causality can contribute to the description of cardiovascular control by suggesting the temporal direction of the interactions and by separating different causality schemes (e.g. closed loop versus unidirectional relations).

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