A coherent detection algorithm for the high-speed targets based on radon inverse fourier transform

Fast-starts are brief, sudden accelerations used by fish during predator-prey encounters. In this paper, a three-dimensional (3D) test and analysis method is critical to understand the function of the pectoral fin during maneuvers. An experiment method based on Fourier Transform Profilometry for 3D pectoral fin profile variety during fish maneuvers is proposed. This method was used in a carp fast-start during prey. Projecting the moiré fringes onto a carp pectoral fin it will produce the deformed fringe patterns contain 3D information. A high speed camera captures these time-sequence images. By Fourier transform, filter, inverse Fourier transform and unwrap these phase maps in 3D phase space, the complex pectoral fin profile variety were really reconstructed. The present study provides a new method to quantify the analysis of kinetic characteristic of the pectoral fin during maneuvers.

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Parameters Affecting Thermo-Meohanical Cracking in Coated Media Due to High-Speed Friction Load

Journal of Tribology ◽

10.1115/1.3261589 ◽

1988 ◽

Vol 110 (2) ◽

pp. 222-227 ◽

Cited By ~ 12

Author(s):

F. D. Ju ◽

J. C. Liu

Keyword(s):

Fourier Transform ◽

Temperature Field ◽

Thermal Stress ◽

High Speed ◽

Coating Layer ◽

Infinite Medium ◽

Thermal Stress State ◽

Heating Effect ◽

Coated Surface ◽

Heat Checking

This investigation considers the thermo-mechanical effects of an asperity traversing at a high speed over a semi-infinite medium with a thin, hard coated surface. The general analytical solution of the temperature field and the thermal stress state are obtained and expressed in Fourier transform space. The analysis emphasizes the heating effect of the friction force, which leads to the initiation of the thermo-mechanical cracking or “heat-checking,” in the coating layer, the substrate, or their interface. For hard coated layers, the initiation of a crack will occur either in the coating layer, the substrate or the interface depending on the relative properties of the coating and the substrate and their bonding strength.

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Based on the CO2 Gas Shielded Welding Molten Pool Image Edge Detection Algorithm

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.437.840 ◽

2013 ◽

Vol 437 ◽

pp. 840-844 ◽

Cited By ~ 1

Author(s):

Xiao Gang Liu ◽

Bing Zhao

Keyword(s):

Edge Detection ◽

Molten Pool ◽

High Speed ◽

Vision System ◽

Detection Algorithm ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Defect Recognition ◽

Pool Image

This paper use the passive vision system through high-speed camera collects molten pool images; and then according to the frequency domain characteristics of the weld pool image Butterworth low-pass filter; gradient method for image enhancement obtained after pretreatment. Research Roberts, Sobel, Prewitt, Log, Zerocross, and Canny 6 both traditional differential operator edge detection processing results. Through comparison and analysis of choosing threshold for [0.1, 0. Canny operator can get the ideal molten pool edge character, for subsequent welding molten pool defect recognition provides favorable conditions.

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Fourier Transform Infrared Spectrophotometer for Transmittance and Diffuse Reflectance Measurements

Applied Spectroscopy ◽

10.1366/000370276774456642 ◽

1976 ◽

Vol 30 (6) ◽

pp. 593-601 ◽

Cited By ~ 53

Author(s):

R. R. Willey

Keyword(s):

Fourier Transform ◽

High Speed ◽

Diffuse Reflectance ◽

Storage System ◽

Fourier Transform Infrared ◽

Single Beam ◽

Double Beam ◽

New Instrument ◽

Measurement Mode ◽

Infrared Spectrophotometer

This paper describes a new Fourier transform infrared spectrophotometer with the capability to measure diffuse reflectance (DR) from 5000 to 500 cm−1 (2 to 20 µm) in addition to the normal transmittance measurements. The instrument has a true simultaneous double beam measurement mode and a high speed single beam mode. The system also takes advantage of many data manipulation and display features due to the built-in computer and 2.5 million word storage system. One of the objectives of this work was to produce a practical instrument which includes the DR capability; another was to introduce the qualitative and quantitative measurements of DR in the infrared to the analytical community. DR has been commonly available in the visible and near ir spectrum, but until this new instrument, has not been available in the ir. A brief survey of the background and history of DR and emittance measurements in the ir is given. The design details and operation of the instrument are generally examined. Brief examples are provided for a few transmittance, trace analysis, and microsampling applications, and a variety of DR results are shown. The addition of diffuse reflectance as a tool in the infrared opens new avenues for investigation and application in many fields.

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Smooth Wavelet Approximations of Truncated Legendre Polynomials via the Jacobi Theta Function

Abstract and Applied Analysis ◽

10.1155/2014/890456 ◽

2014 ◽

Vol 2014 ◽

pp. 1-24 ◽

Cited By ~ 2

Author(s):

David W. Pravica ◽

Njinasoa Randriampiry ◽

Michael J. Spurr

Keyword(s):

Fourier Transform ◽

Theta Function ◽

Legendre Polynomial ◽

Legendre Polynomials ◽

Inverse Fourier Transform ◽

Recursion Relations ◽

Jacobi Theta Function ◽

Convergence Results ◽

The Family ◽

Reciprocal Symmetry

The family ofnth orderq-Legendre polynomials are introduced. They are shown to be obtainable from the Jacobi theta function and to satisfy recursion relations and multiplicatively advanced differential equations (MADEs) that are analogues of the recursion relations and ODEs satisfied by thenth degree Legendre polynomials. Thenth orderq-Legendre polynomials are shown to have vanishingkth moments for0≤k<n, as does thenth degree truncated Legendre polynomial. Convergence results are obtained, approximations are given, a reciprocal symmetry is shown, and nearly orthonormal frames are constructed. Conditions are given under which a MADE remains a MADE under inverse Fourier transform. This is used to construct new wavelets as solutions of MADEs.

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