Three-dimensional and two-dimensional sequence spatial-frequency domain processing of speckled ladar images for automatic target recognition

1999 ◽  
Author(s):  
Douglas G. Youmans ◽  
George A. Hart
Keyword(s):  
Spatial Frequency ◽  
Frequency Domain ◽  
Target Recognition ◽  
Three Dimensional ◽  
Automatic Target Recognition ◽  
Two Dimensional ◽  
Spatial Frequency Domain ◽  
Frequency Domain Processing

Spatial Frequency Domain Analysis of Heat Transfer in Microelectronic Chips With Applications to Temperature Aware Computing

2007 ◽  
Author(s):  
Keivan Etessam-Yazdani ◽  
Hendrik F. Hamann ◽  
Mehdi Asheghi
Keyword(s):  
Transfer Function ◽  
Spatial Frequency ◽  
Frequency Domain ◽  
Thermal Power ◽  
Three Dimensional ◽  
Heat Removal ◽  
Frequency Domain Analysis ◽  
Heat Diffusion ◽  
The Impact ◽  
Spatial Frequency Domain

In this paper we present a novel analytical approach for obtaining the thermal transfer function of multi-layer chips in the spatial frequency domain. The behavior of the transfer function is used to address a number of key issues such as 1) the appropriate power granularity required for microarchitecture thermal-power analysis, and 2) the impact of packaging and cooling solutions on heat removal from chip hotspots. The merit of the presented method is in 1) simplicity, such that even for rather complicated multi-layer structures the analysis takes only a fraction of a second, and 2) accuracy, because the approach is based on the exact solution of three-dimensional heat diffusion equations.

Study on Spatial Frequency Domain Algorithm and White Light Interference System Based on NMM

2015 ◽  
Vol 738-739 ◽  
pp. 904-910
Author(s):  
Li Jian ◽  
Li Hua Lei ◽  
Dong Sheng Li ◽  
Yun Xia Fu ◽  
Yuan Li ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Frequency Domain ◽  
White Light ◽  
Three Dimensional ◽  
Step Height ◽  
Light Interference ◽  
Interference System ◽  
Measuring Machine ◽  
White Light Interference ◽  
Spatial Frequency Domain

White light interference technique for topography measurement effectively avoids phase ambiguity in phase-shifting interferometry. The spatial frequency domain algorithm based on scanning white light interference technique has the advantage of insensitivity to noise and higher calculation accuracy compared with other methods. The white light interference sensor is constructed based on nano positioning and nano measuring machine (NMM), the calibrated step height standard of 100±3nm is measured. The spatial frequency domain algorithm is adopted for data processing, the repetitive test result of 97.9nm and standard deviation of 0.48nm are achieved. To verify the measuring ability of complex device, the number ‘242’ on ink box is measured and three-dimensional reconstruction is conducted. The high precision and traceable measurements of micro/nano scale step height standard and complex devices are realized by the white light interference system based on NMM with steady frequency laser interferometer built-in.

Spin Spatial Frequency Response of Atomic Magnetometer

2018 ◽  
Vol 787 ◽  
pp. 81-86 ◽  
Author(s):  
Ling Xiao Yin ◽  
Jing Ling Chen
Keyword(s):  
Magnetic Field ◽  
Spatial Frequency ◽  
Frequency Response ◽  
Frequency Domain ◽  
Three Dimensional ◽  
Vapor Cell ◽  
Spatial Characterization ◽  
Alternative Magnetic Field ◽  
Theoretical Results ◽  
Spatial Frequency Domain

We describe a method for measuring the spin spatial frequency response in a Cs vapor cell by using a digital micro-mirror device (DMD) to modulate the pumping light both spatially and temporally. An equivalent space-alternative magnetic field is created by this way. The pumping light through the Cs vapor cell is measured and analyzed in spatial frequency domain. We obtain the spatial frequency response of the Cs vapor cell from 1.4 cm-1to 364.9 cm-1. The theoretical results of the spatial frequency response according to Fick's second diffusion law agree with the experimental results. This method provides an alternate approach for spatial characterization and three-dimensional imaging of spins.

scholarly journals Sliding signal processing in telecommunication networks based on two-dimensional discrete Fourier transform

2019 ◽  
Vol 30 ◽  
pp. 04013
Author(s):  
Vladimir Ponomarev ◽  
Olga Ponomareva ◽  
Alexey Ponomarev ◽  
Natalya Smirnova
Keyword(s):  
Signal Processing ◽  
Fourier Transform ◽  
Spatial Frequency ◽  
Frequency Domain ◽  
Discrete Fourier Transform ◽  
Telecommunication Networks ◽  
Mathematical Representation ◽  
Two Dimensional ◽  
Discrete Signals ◽  
Spatial Frequency Domain

A method of vertical sliding processing of two-dimensional discrete signals in the spatial frequency domain is proposed — a method of fast vertically sliding two-dimensional discrete Fourier transform. The mathematical representation of the two-dimensional discrete Fourier transform in algebraic and matrix form is considered. An effective method of vertically sliding two-dimensional discrete Fourier transform is proposed. The algorithm developed in the framework of the proposed method allows calculating the coefficients (bins) of this transformation in real time.

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