Results 251 to 260 of about 255,632 (300)

Frequency modulation spectroscopy with second harmonic detection

Applied Optics, 1985
La demodulation du second harmonique permet d'obtenir un meilleur rapport signal sur bruit avec des lasers a largeur de raie relativement ...
G, Janik, C, Carlisle, T F, Gallagher
openaire   +2 more sources

Harmonic and Inter-harmonic Detecting Based on Support Vector Machine

2005 IEEE/PES Transmission & Distribution Conference & Exposition: Asia and Pacific, 2005
Based on the linear regressive model of the support vector machine, the paper introduces iterative re-weighted least squares of the support vector machine for signal spectral analysis by virtue of abstract expressions of cost functions, and the uniform mathematical analytical expression of support vector machine for solving the problem of signal ...
null Li Ma, null Kaipei Liu, null Lanfang Li   +2 more
openaire   +1 more source

Harmonic and inter-harmonic detection based on synchrosqueezed wavelet transform

2016 IEEE Information Technology, Networking, Electronic and Automation Control Conference, 2016
To perfectly detect the amplitude for high frequency harmonic and inter-harmonic of small signal, separate the close frequency and improve accuracy of the detection time in dynamic system, a harmonic and inter-harmonic detection method based on synchrosqueezed wavelet transforms (SST) is proposed.
Man Weishi, Wang Jianhua, Kang Qing
openaire   +1 more source

Harmonic Distortion Estimate for Damage Detection

NAECON 2018 - IEEE National Aerospace and Electronics Conference, 2018
The ultrasonic techniques of flaws detection and evaluation usually rely on linear models. High mechanical stress generates non-linear phenomena. Models suited to fit the input-output characteristics and the existence of non-linear behaviors, if any, allow improved sensitivity and early detection of the onset of cracks.
Burrascano P., Laureti S., Ricci M.
openaire   +1 more source

Harmonic Detection for Hybrid Filter

2011
Harmonic distortion can be caused by both active and passive nonlinear devices in a power system. These harmonic currents can cause voltage distortion and excessive power losses in the system. To maintain high quality power supply, the system harmonic levels must be measured and kept under control.
Yunjing Liu, Fengwen Wang
openaire   +1 more source

RF arc detection using harmonic signals

Proceedings of 16th International Symposium on Fusion Engineering, 2002
A new technique for arc detection in high power RF systems is being tested on the TFTR and DIII-D ICRF systems. Because the arc is nonlinear, it generates harmonics of the operating frequency as well as broadband low frequency noise. These bands of the spectrum can be detected from a coupled signal which passes through the appropriate frequency filter.
J.H. Rogers, P. LaRue, D.A. Phelps, R.I. Pinsker   +3 more
openaire   +1 more source

An improved method for harmonic detecting

2008 7th World Congress on Intelligent Control and Automation, 2008
This paper presents an improved method for harmonic detecting based on instantaneous reactive power theory. It changes the distribution of zero-pole by inserting a leading network in harmonic detecting system and the harmonic detecting system has the characters of ideal high-pass filter.
null Jinglei Guo, null Yong Wu
openaire   +1 more source

Detection of harmonic burst signals

International Journal of Circuit Theory and Applications, 1985
AbstractThe proposed procedure and the corresponding circuits for the recognition of a frequency from a set of possible input frequencies in the frame of a time‐window interval seem to be advantageous as they lead to simpler hardware than the well‐known energy detector. A unique feature is the single channel processing possibility.
openaire   +1 more source

Emboli detection and discrimination using harmonics

2000 IEEE Ultrasonics Symposium. Proceedings. An International Symposium (Cat. No.00CH37121), 2002
The characterization of gaseous emboli is of high interest for clinical decision making after surgery. In this study, a new approach using the nonlinear behavior of gaseous emboli is presented. An in-vitro set-up was developed to generate air bubbles of uniform sizes, with diameter ranging from 19 /spl mu/m to 200 /spl mu/m to simulate gaseous emboli ...
Palanchon, P, Meeder, H, Klein, Jan, Bom, Klaas, Jong, Nico   +4 more
openaire   +2 more sources

Detection of remote harmonics using SVD

8th International Conference on Harmonics and Quality of Power. Proceedings (Cat. No.98EX227), 2002
The paper examines the singular value decomposition (SVD) for detection of remote harmonics in signals, in the presence of high noise contaminating the measured waveform. When the number of harmonics is very large and at the same time certain harmonics are distant from the other, the conventional frequency detecting methods are not satisfactory.
T. Lobos, T. Kozina, S. Osowski
openaire   +1 more source