Terahertz absorbance spectrum fitting method for quantitative detection of concealed contraband

2007 ◽  
Vol 102 (11) ◽  
pp. 113108 ◽  
Author(s):  
Yingxin Wang ◽  
Ziran Zhao ◽  
Zhiqiang Chen ◽  
Kejun Kang ◽  
Bing Feng ◽  
...  
Keyword(s):  
Quantitative Detection ◽  
Absorbance Spectrum ◽  
Fitting Method ◽  
Spectrum Fitting

Application of Simulated Annealing Particle Swarm Optimization in Response Spectrum Fitting of Simulated Earthquake Wave

2013 ◽  
Vol 444-445 ◽  
pp. 1082-1086
Author(s):  
Xue Ni Wang ◽  
Jing Zhou
Keyword(s):  
Particle Swarm Optimization ◽  
Simulated Annealing ◽  
Optimization Algorithm ◽  
Particle Swarm Optimization Algorithm ◽  
Response Spectrum ◽  
Particle Swarm ◽  
Swarm Optimization ◽  
Fitting Method ◽  
Design Response Spectrum ◽  
Spectrum Fitting

In order to get a simulated earthquake wave whose response spectrum fitted well to the smooth design response spectrum, a model was established by making the standard error between the response spectrum of simulated earthquake wave and the design response spectrum as the minimal optimization objective. Simulated annealing particle swarm optimization algorithm, which was an improvement algorithm of particle swarm optimization, was used to solve the model. This spectrum fitting method was compared with the conventional spectrum fitting method, which adjusted Fourier amplitude spectrum in frequency domain. The results show that the method of response spectrum fitting by applying simulated annealing particle swarm optimization algorithm has a good convergence. And the response spectrum of simulated earthquake wave generated by simulated annealing particle swarm optimization algorithm agrees better with the design response spectrum than that by conventional spectrum fitting method.

scholarly journals The Age-Redshift Relation For LRGs

2012 ◽  
Vol 8 (S295) ◽  
pp. 179-179
Author(s):  
Gaochao Liu ◽  
Youjun Lu ◽  
Xuelei Chen ◽  
Yongheng Zhao ◽  
Wei Du ◽  
...  
Keyword(s):  
Hubble Parameter ◽  
Cosmological Models ◽  
Full Spectrum ◽  
Relative Age ◽  
Luminous Red Galaxies ◽  
Fitting Method ◽  
The Mean ◽  
Velocity Dispersions ◽  
Red Galaxies ◽  
Spectrum Fitting

AbstractThe relative age of galaxies at different redshifts can be used to infer the Hubble parameter and put constraints on cosmological models. We select 23,883 quiescent luminous red galaxies (LRGs) from the SDSS DR7, dividing them into four sub-samples according to their velocity dispersions. Each sub-sample was further divided into 12 redshift bins. The spectra of the LRGs in each redshift and velocity bin were co-added. Adopting the GalexEV/SteLib model, we estimate the mean ages of the LRGs from these combined spectra by the full-spectrum fitting method and find it is consistent with the well known “downsizing” formation of galaxies. Based on the age–redshift relation, we further estimate the Hubble parameter.

Simultaneous demodulation comparison of fiber-optic Fabry–Perot sensors connected in parallel and series

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jie Liao ◽  
Wenlin Feng ◽  
Xiaozhan Yang
Keyword(s):  
Fiber Optic ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Parallel Structure ◽  
Theoretical Formula ◽  
Series Connection ◽  
Fitting Method ◽  
Fabry Perot ◽  
Spectrum Fitting

Abstract In this work, the spectra of two fiber-optic Fabry–Perot sensors in parallel and series connection were studied. The spectrum of the parallel structure is a simple superposition of the two sensors’ spectrum, and that of the series structure can be regarded as the interference occurring in two Fabry–Perot sensors successively. The sensors’ optical path difference can be obtained and separated by using the theoretical formula to fit the normalized spectrum of parallel or series structure, which showed that two or more Fabry–Perot sensors can be simultaneously demodulated by the spectrum fitting method.

Fast Neutron Capture in Tl, Hg, Au, and Ta and Gamma Ray Strength Functions

1974 ◽  
Vol 52 (11) ◽  
pp. 989-998 ◽  
Author(s):  
E. D. Earle ◽  
M. A. Lone ◽  
G. A. Bartholomew ◽  
W. J. McDonald ◽  
K. H. Bray ◽  
...  
Keyword(s):  
Neutron Capture ◽  
Gamma Ray ◽  
Strength Function ◽  
Detector Response ◽  
Strong Decrease ◽  
Fitting Method ◽  
Spectral Distributions ◽  
Γ Ray ◽  
Strength Functions ◽  
Spectrum Fitting

Gamma ray spectra following the capture of 0.7, 1.7, and 2.6 MeV neutrons in Tl and Hg, of 0.7 and 2.6 MeV neutrons in Ta, and of 2.6 MeV neutrons in Au were measured with a NaI detector. The spectral distributions were obtained by unfolding the detector response function, and γ-ray strength functions were deduced for Tl, Au, and Ta by a spectrum fitting method. The strength functions in Tl and Au, when compared with the Lorentzian predictions, show a strong decrease below ~5 MeV and in Tl there is a resonance-like structure at ~5.5 MeV. No such structure is found in the strength function for Ta. This behavior is qualitatively interpreted in terms of recent particle–hole calculations.

Interference-aided spectrum-fitting method for accurate film thickness determination

2016 ◽  
Vol 14 (8) ◽  
pp. 081203-81207 ◽  
Author(s):  
Xingxing Liu Xingxing Liu ◽  
Shaowei Wang Shaowei Wang ◽  
Hui Xia Hui Xia ◽  
Xutao Zhang Xutao Zhang ◽  
Ruonan Ji Ruonan Ji ◽  
...  
Keyword(s):  
Film Thickness ◽  
Thickness Determination ◽  
Fitting Method ◽  
Spectrum Fitting
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