An Algorithm for Best-Fit of a Pattern of Profile Features to the True Profile

In industrial metrology, measurement and assessment of standard profile features such as planes, cylinders, cones, etc. is an important part. Many algorithms for fitting and noise-reduction of range data from single feature have been proposed. However, according to the definition of workpiece or requirement of drawing, best-fit operation of a pattern of profile features to the true profile should be taken, which requires considering several different features as a whole to fit to the true profile. Currently there’s not so much papers related with this problem. On basis of algorithms for fitting of single profile feature and noise reduction methods, an algorithm for best-fit of a pattern of profile features was presented in this paper. Since it is a nonlinear optimization problem, a method of finding initial estimates was also related in this paper, which is also helpful for the fitting of single cylinder, cone and other standard quadric surfaces.

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Finding Global Minima with a Filled Function Approach for Non-Smooth Global Optimization

Discrete Dynamics in Nature and Society ◽

10.1155/2010/843609 ◽

2010 ◽

Vol 2010 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Weixiang Wang ◽

Youlin Shang ◽

Ying Zhang

Keyword(s):

Global Optimization ◽

Optimization Problem ◽

Numerical Test ◽

Function Approach ◽

Global Optimization Problem ◽

Computational Results ◽

Filled Function ◽

Global Minima ◽

Smooth Case ◽

Definition Of

A filled function approach is proposed for solving a non-smooth unconstrained global optimization problem. First, the definition of filled function in Zhang (2009) for smooth global optimization is extended to non-smooth case and a new one is put forwarded. Then, a novel filled function is proposed for non-smooth the global optimization and a corresponding non-smooth algorithm based on the filled function is designed. At last, a numerical test is made. The computational results demonstrate that the proposed approach is effcient and reliable.

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On the Running Noise of Toothed Belt Drive : 2nd Report, Influence of Running Condition and Some Noise Reduction Methods

Transactions of the Japan Society of Mechanical Engineers ◽

10.1299/kikai1938.37.203 ◽

1971 ◽

Vol 37 (293) ◽

pp. 203-211

Author(s):

Aizoh KUBO ◽

Toshiaki ANDO ◽

Susumu SATO ◽

Toshio AIDA ◽

Takeshi HOSHIRO

Keyword(s):

Noise Reduction ◽

Belt Drive ◽

Toothed Belt ◽

Reduction Methods

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COMPARISON OF MONOPOLE AND DIPOLE NOISE REDUCTION METHODS

VESTNIK OF VORONEZH STATE AGRARIAN UNIVERSITY ◽

10.17238/issn2071-2243.2020.4.153 ◽

2020 ◽

Vol 4 (67) ◽

pp. 153-160

Author(s):

Oleg I. Polivaev ◽

◽

Alexey N. Kuznetsov ◽

Dmitriy Yu. Terekhov ◽

Viktor V. Trufanov ◽

...

Keyword(s):

Noise Reduction ◽

Reduction Methods

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Noise Reduction During Acoustic Monitoring of Laser Welding of High-Strength Steels

ASME 2009 International Manufacturing Science and Engineering Conference, Volume 1 ◽

10.1115/msec2009-84080 ◽

2009 ◽

Author(s):

Wei Huang ◽

Radovan Kovacevic

Keyword(s):

Laser Welding ◽

Noise Reduction ◽

Acoustic Signal ◽

Welding Process ◽

High Strength Steels ◽

High Strength ◽

Weld Penetration ◽

Acoustic Signatures ◽

Reduction Methods ◽

Laser Welding Process

During the laser welding process of high-strength steels, different defects, such as a partial weld penetration, spatters, and blow-through holes could be present. In order to detect the presence of defects and achieve a quality control, acoustic monitoring based on microphones is applied to the welding process. As an effective sensor to monitor the laser welding process, however, the microphone is greatly limited by intensive noise existing in the complex industrial environment. In this paper, in order to acquire a clean acoustic signal from the laser welding process, two noise reduction methods are proposed: one is the spectral subtraction method based on one microphone and the other one is the beamforming based on a microphone array. By applying these two noise reduction methods, the quality of the acoustic signal is enhanced, and the acoustic signatures are extracted both in the time domain and frequency domain. The analysis results show that the extracted acoustic signatures can well indicate the different weld penetration states and they can also be used to study the internal mechanisms of the laser-material interaction.

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Improved Turbulence Profiling with Field-Adapted Acoustic Doppler Velocimeters Using a Bifrequency Doppler Noise Suppression Method

Journal of Atmospheric and Oceanic Technology ◽

10.1175/2007jtecho512.1 ◽

2008 ◽

Vol 25 (3) ◽

pp. 452-463 ◽

Cited By ~ 28

Author(s):

D. Hurther ◽

U. Lemmin

Keyword(s):

Noise Reduction ◽

Carrier Frequency ◽

Noise Suppression ◽

Isotropic Turbulence ◽

Field Studies ◽

Sample Volume ◽

Grid Turbulence ◽

Electronic Circuitry ◽

Reduction Methods ◽

Velocity Spectra

Abstract A novel noise reduction method and corresponding technique are presented for improving turbulence measurements with acoustic Doppler velocimeters (ADVs) commonly used in field studies of coastal and nearshore regions, rivers, lakes, and estuaries. This bifrequency method is based on the decorrelation of the random and statistically independent Doppler noise terms contained in the Doppler signals at two frequencies. It is shown through experiments in an oscillating grid turbulence (OGT) tank producing diffusive isotropic turbulence that a shift in carrier frequency of less than 10% is sufficient to increase the resolved frequency range by a decade in the turbulent velocity spectra. Over this spectral range, the slope of the velocity spectra agrees well with the universal inertial range value of −5/3. The limit due to spatial averaging effects over the sample volume can be determined from the abrupt deviation of the spectral slope from the −5/3 value. As a result, the relative error of the turbulent intensity estimate and the turbulent kinetic energy (TKE) dissipation rate, measured by two different methods, does not exceed 10% in the case of isotropic turbulence. Furthermore, the bifrequency method allows accurate estimates of the turbulent microscales as shown by the good agreement of the ratio between the Taylor and Kolmogorov microscales and an Re1/4t power law. Compared to previous Doppler noise reduction methods (Garbini et al.), an increase in time resolution by a factor of 4 is achieved. The proposed method also avoids the loss of TKE energy contained in isotropic flow structures of size equal to and smaller than the sample volume. Different from Doppler noise methods proposed by Hurther and Lemmin and Blanckaert and Lemmin, this method does not require additional hardware components, electronic circuitry, or sensors because the redundant instantaneous velocity field information is captured with the same transducer. The required shift in carrier frequency is small enough for the bifrequency method to be easily implemented in commercial ADVs.

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The Application of Computer Simulation Technology in the Queuing System Optimization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.3849 ◽

2014 ◽

Vol 556-562 ◽

pp. 3849-3851

Author(s):

Rong Hua Tan

Keyword(s):

Computer Simulation ◽

Queuing Theory ◽

Optimization Problem ◽

Classical Model ◽

Discrete Event ◽

System Optimization ◽

Discrete Event System ◽

Queuing System ◽

Event System ◽

Definition Of

The optimization Problem of queuing system is an important research subject in the queuing system.There are two ways to solve this problem:one is the traditional theoretical analysis, the other is the application of computer simulation. This thesis introduces the queuing theory and the simulation technique of discrete event system, including fundamental conceptions, methods, performance index and classical model of queuing system, as well as the definition of simulation and the procedure of the simulation of discrete event system. And procedure and parameters set of general modeling methods are analyzed.

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