Optimal parameters of linear source with working face lying along optical axis

The goafs caused by coal mining cause great harm to the surface farmland, buildings, and personal safety. The existing monitoring methods cost a lot of workforce and material resources. Therefore, this paper proposes an inversion approach for establishing the locations of underground goafs and the parameters of the probability integral method (PIM), thus integrating distributed scatter interferometric synthetic aperture radar (DS-InSAR) data and the PIM. Firstly, a large amount of surface deformation observation data above the goaf are obtained by DS-InSAR, and the line-of-sight deformation is regarded as the true value. Secondly, according to the obtained surface deformations, the ranges of eight goaf location parameters and three PIM parameters are set. Thirdly, a correlation function between the surface deformation and the underground goaf location is constructed. Finally, a particle swarm optimization algorithm is used to search for the optimal parameters in the range of the set parameters to meet the requirement for minimum error between the surface deformation calculated by PIM and the line-of-sight deformation obtained by DS-InSAR. These optimal parameters are thus regarded as the real values of the position of the underground goaf and the PIM parameters. The simulation results show that the maximum relative error between the position of the goaf and the PIM parameters is 2.11%. Taking the 93,604 working face of the Zhangshuanglou coal mine in the Peibei mining area as the research object and 12 Sentinel-1A images as the data source, the goaf location and PIM parameters of the working face were successfully inverted. The inversion results show that the maximum relative error in the goaf location parameters was 16.61%, and the maximum relative error in the PIM parameters was 26.67%.

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Analysis of 3-d molecular distribution with the digital imaging microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102286 ◽

1988 ◽

Vol 46 ◽

pp. 40-41

Author(s):

W.A. Carrington ◽

F.S. Fay ◽

K.E. Fogarty ◽

L. Lifshitz

Keyword(s):

Image Restoration ◽

Digital Imaging ◽

Fluorescent Dyes ◽

Optical Axis ◽

Computer Hardware ◽

Computer Algorithms ◽

Low Contrast ◽

Specific Proteins ◽

Effective Use ◽

Single Living Cells

Advances in digital imaging microscopy and in the synthesis of fluorescent dyes allow the determination of 3D distribution of specific proteins, ions, GNA or DNA in single living cells. Effective use of this technology requires a combination of optical and computer hardware and software for image restoration, feature extraction and computer graphics.The digital imaging microscope consists of a conventional epifluorescence microscope with computer controlled focus, excitation and emission wavelength and duration of excitation. Images are recorded with a cooled (-80°C) CCD. 3D images are obtained as a series of optical sections at .25 - .5 μm intervals.A conventional microscope has substantial blurring along its optical axis. Out of focus contributions to a single optical section cause low contrast and flare; details are poorly resolved along the optical axis. We have developed new computer algorithms for reversing these distortions. These image restoration techniques and scanning confocal microscopes yield significantly better images; the results from the two are comparable.

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Field Distribution of Strongly Excited Magnetic Lenses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114323 ◽

1975 ◽

Vol 33 ◽

pp. 140-141

Author(s):

M. Strojnik

Keyword(s):

Flux Density ◽

Field Distribution ◽

Optical Axis ◽

Operating Point ◽

Pole Piece ◽

Partial Saturation ◽

Axial Flux ◽

The Stability

Magnetic lenses operating in partial saturation offer two advantages in HVEM: they exhibit small cs and cc and their power depends little on the excitation IN. Curve H, Fig. 1, shows that the maximal axial flux density Bz max of one of the lenses investigated changes between points (3) and (4) by 5% as the excitation varies by 40%. Consequently, the designer can relax the requirements concerning the stability of the lens current supplies. Saturated lenses, however, can only be used if (i) unwanted fields along the optical axis can be controlled, (ii) 'wobbling' of the optical axis due to inhomogeneous saturation around the pole piece faces is prevented, (iii) ample ampere-turns can be squeezed into the space available, and (iv) the lens operating point covers a sufficient range of accelerating voltages.

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Calculation And Experimental Substantiation Of Optimal Design Of The Welded Joint Of Plates On Соver Plates

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2020.03.17-24 ◽

2020 ◽

pp. 17-24

Keyword(s):

Welded Joint ◽

Experimental Studies ◽

Engineering Calculation ◽

Tensile Tests ◽

Physical Nonlinearity ◽

Steel Plates ◽

Optimal Parameters ◽

Actual Problem ◽

Numerical Research ◽

Cover Plates

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.

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