In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution...In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution and accuracy than conventional extensometers.However,the relation between the magnification ratio and the structure size of the displacement amplifier is a bottleneck of sensing device design.Addressing this,the magnification ratio of a mechanical displacement amplifier is analytically derived based on its geometry structure.Six prototypes of the displacement amplifier made in propathene are manufactured,and an experimental system is set up to validate the accuracy of the established magnification ratio equation.Theoretical magnification ratios and experimental magnification ratios are compared and agree well,which verifies that the proposed equation is reliable.This analytical equation provides an effective design method for bridge-shaped mechanical displacement amplifiers with an expected magnification ratio.展开更多
Tunnel deformation is a direct manifestation of the stress redistribution of rock and soil masses,and high-precision monitoring of it is an important challenge in the eld of geophysical engineering.This study applies ...Tunnel deformation is a direct manifestation of the stress redistribution of rock and soil masses,and high-precision monitoring of it is an important challenge in the eld of geophysical engineering.This study applies the improved PS-InSAR technology to tunnel deformation monitoring,overcoming the limitations of traditional methods(such as total stations)with limited spatial coverage and poor continuity.Four core innovations enable millimeter-level precision breakthroughs:adaptive quality map fusion of coherence coefficientγand phase derivative variance for dynamic reliable area partitioning;branch-cutting method optimization using residual point clustering and Canny forbidden-zone constraints reduces invalid paths by 40%while suppressing lining joint phase jumps;dynamic weighted least squares(WLS)model integrating weighted coherence with blast disturbance gradient achieves 52%high-frequency noise suppression and precise separation of short-period construction disturbance signals;3D integral correction introduces DEM dynamic calibration projection coefcient k(improving by 30%in curved sections),reducing axial projection error from 15%-30%to<5%.In the Yunnan Amai Tunnel eld test,spatial resolution reaches 0.1m in sensitive zones with deformation inversion error<5%,successfully capturing instantaneous blasting deformation(0.46-0.49mm)and structural trend displacement at the face.The monitoring accuracy is more than three times higher than traditional methods,providing reliable technical support for safety warnings in high-risk sections.展开更多
A distortion correction method for the elemental images of integral imaging（Ⅱ） by utilizing the directional diffuser is demonstrated. In the traditional Ⅱ, the distortion originating from lens aberration wraps ele...A distortion correction method for the elemental images of integral imaging（Ⅱ） by utilizing the directional diffuser is demonstrated. In the traditional Ⅱ, the distortion originating from lens aberration wraps elemental images and degrades the image quality severely. According to the theoretical analysis and experiments, it can be proved that the farther the three-dimensional image is displayed from the lens array, the more serious the distortion is. To analyze the process of eliminating lens distortion, one lens and its corresponding elemental image are separated from the traditional Ⅱ. By introducing the directional diffuser, the aperture stop of the separated optical system changes from the eye＇s pupil to the lens. In terms of contrast experiments, the distortion of the improved display system is corrected effectively. In the experiment, when the distance between the reconstructed image and lens array is equal to 120 mm, the largest lens distortion is decreased from 46.6% to 3.3%.展开更多
Based on the modern monetary theory, this paper analyze the relation between interest rate policy and Shanghai and Shenzhen Stock Exchange by using event study and co\|integration model method. We point out that the i...Based on the modern monetary theory, this paper analyze the relation between interest rate policy and Shanghai and Shenzhen Stock Exchange by using event study and co\|integration model method. We point out that the interest rate policy have some abnormal effects on the stock market in short time and have negative effects on the stock market in long run. The influence of the interest rate is different on Shanghai Stock Exchange and Shenzhen Stock Exchange.展开更多
基金supported by the 111 Project of China(No.B13020)the Shanghai Pujiang Program(No.15PJD010)
文摘In order to monitor deformation of high temperature components for a long time,a sensing device integrating a bridge-shaped mechanical displacement amplifier has been designed.This sensing device has higher resolution and accuracy than conventional extensometers.However,the relation between the magnification ratio and the structure size of the displacement amplifier is a bottleneck of sensing device design.Addressing this,the magnification ratio of a mechanical displacement amplifier is analytically derived based on its geometry structure.Six prototypes of the displacement amplifier made in propathene are manufactured,and an experimental system is set up to validate the accuracy of the established magnification ratio equation.Theoretical magnification ratios and experimental magnification ratios are compared and agree well,which verifies that the proposed equation is reliable.This analytical equation provides an effective design method for bridge-shaped mechanical displacement amplifiers with an expected magnification ratio.
基金supported by the Science and Technology Innovation and Demonstration Project of the Department of Transport of Yunnan Province(Project No.2023-166).
文摘Tunnel deformation is a direct manifestation of the stress redistribution of rock and soil masses,and high-precision monitoring of it is an important challenge in the eld of geophysical engineering.This study applies the improved PS-InSAR technology to tunnel deformation monitoring,overcoming the limitations of traditional methods(such as total stations)with limited spatial coverage and poor continuity.Four core innovations enable millimeter-level precision breakthroughs:adaptive quality map fusion of coherence coefficientγand phase derivative variance for dynamic reliable area partitioning;branch-cutting method optimization using residual point clustering and Canny forbidden-zone constraints reduces invalid paths by 40%while suppressing lining joint phase jumps;dynamic weighted least squares(WLS)model integrating weighted coherence with blast disturbance gradient achieves 52%high-frequency noise suppression and precise separation of short-period construction disturbance signals;3D integral correction introduces DEM dynamic calibration projection coefcient k(improving by 30%in curved sections),reducing axial projection error from 15%-30%to<5%.In the Yunnan Amai Tunnel eld test,spatial resolution reaches 0.1m in sensitive zones with deformation inversion error<5%,successfully capturing instantaneous blasting deformation(0.46-0.49mm)and structural trend displacement at the face.The monitoring accuracy is more than three times higher than traditional methods,providing reliable technical support for safety warnings in high-risk sections.
基金supported by the Natural National Science Foundation of China(NSFC)(No.61705014)the Fundamental Research Funds for the Central Universities(No.2016ZX01)+1 种基金the fund of the State Key Laboratory of Information Photonics and Optical CommunicationsThe "863" Program(No.2015AA015902)
文摘A distortion correction method for the elemental images of integral imaging（Ⅱ） by utilizing the directional diffuser is demonstrated. In the traditional Ⅱ, the distortion originating from lens aberration wraps elemental images and degrades the image quality severely. According to the theoretical analysis and experiments, it can be proved that the farther the three-dimensional image is displayed from the lens array, the more serious the distortion is. To analyze the process of eliminating lens distortion, one lens and its corresponding elemental image are separated from the traditional Ⅱ. By introducing the directional diffuser, the aperture stop of the separated optical system changes from the eye＇s pupil to the lens. In terms of contrast experiments, the distortion of the improved display system is corrected effectively. In the experiment, when the distance between the reconstructed image and lens array is equal to 120 mm, the largest lens distortion is decreased from 46.6% to 3.3%.
文摘Based on the modern monetary theory, this paper analyze the relation between interest rate policy and Shanghai and Shenzhen Stock Exchange by using event study and co\|integration model method. We point out that the interest rate policy have some abnormal effects on the stock market in short time and have negative effects on the stock market in long run. The influence of the interest rate is different on Shanghai Stock Exchange and Shenzhen Stock Exchange.
