Disturbance rejection performance for rolling hydraulic position control system has always been a knotty issue. To guarantee the transient performance and improve disturbance rejection performance of the rolling hydra...
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To address the incomplete problem in pulmonary parenchyma segmentation based on the traditional methods, a novel automated segmentation method based on an eight- neighbor region growing algorithm with left-right scann...
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To address the incomplete problem in pulmonary parenchyma segmentation based on the traditional methods, a novel automated segmentation method based on an eight- neighbor region growing algorithm with left-right scanning and four-corner rotating and scanning is proposed in this pa- per. The proposed method consists of four main stages： image binarization, rough segmentation of lung, image denoising and lung contour refining. First, the binarization of images is done and the regions of interest are extracted. After that, the rough segmentation of lung is performed through a general region growing method. Then the improved eight-neighbor region growing is used to remove noise for the upper, mid- dle, and bottom region of lung. Finally, corrosion and ex- pansion operations are utilized to smooth the lung boundary. The proposed method was validated on chest positron emis- sion tomography-computed tomography （PET-CT） data of 30 cases from a hospital in Shanxi, China. Experimental results show that our method can achieve an average volume overlap ratio of 96.21 ± 0.39% with the manual segmentation results. Compared with the existing methods, the proposed algorithm segments the lung in PET-CT images more efficiently and ac- curately.
A distributed optical fiber acoustic sensor based on in-line Sagnac is *** clockwise and counterclockwise light waves are recombined,interference in3X3coupler is *** acoustic sensor uses photo detector(PD),data acquis...
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A distributed optical fiber acoustic sensor based on in-line Sagnac is *** clockwise and counterclockwise light waves are recombined,interference in3X3coupler is *** acoustic sensor uses photo detector(PD),data acquisition card,filter and amplification to realize photo electric conversion and recover acoustic *** study the performance of this acoustic sensor,localization principle based on null frequency is *** reveal null frequencies from the acoustic disturbance position,a fast Fourier transform(F F T)is applied to transform time domain signal data into frequency domain *** results demonstrate that the Sagnac distributed optical fiber sensor can retransmit acoustic signal and the location performance is verified by simulation and experiment.
In this paper the preliminary research results of distributed optical fiber vibration detection system based on-OTDR are introduced This technology has a fine positioning accuracy of less than 20 m and multi-point pos...
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In this paper the preliminary research results of distributed optical fiber vibration detection system based on-OTDR are introduced This technology has a fine positioning accuracy of less than 20 m and multi-point positioning capability for the vibration signal within a 4 km sensing fiber. The dynamic frequency range has been currently validated between 1 Hz and 60 Hz. These results provide the reference for the vibration detection in the mechanical fault diagnosis.
Nonlinear dynamics of a semiconductor laser subjected external optical is applied to all-optical clock division. By properly adjusting the injection conditions, the divide-by-two clock division and the divide-by-three...
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Results of the analysis of published measurements of the air bubbles content in sea ice are presented. The study of interrelation of porosity (gas content) and salinity of ice was carried out and it was revealed their...
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Based on the weak conductor characteristics of the ice and the difference of the resistance value and capacity value of air, ice and water with varied temperature, a novel measure method for the circumstance of ice an...
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Based on the weak conductor characteristics of the ice and the difference of the resistance value and capacity value of air, ice and water with varied temperature, a novel measure method for the circumstance of ice and water is presented, which included resistance mode and capacity mode. The system has been applied to all-climate automation monitor and measurement for the circumstance of ice and water.
It is a new testing technology that ice thickness is measured by making use of electric conductivity in water and in ice. The electric conductivity in water gradually decrease from strong to weak during the state of w...
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ISBN:
(纸本)9806560612
It is a new testing technology that ice thickness is measured by making use of electric conductivity in water and in ice. The electric conductivity in water gradually decrease from strong to weak during the state of water changing from liquid into solid. Bases on this characteristics, a new sensor structure for measuring thickness of ice layer and its testing method are developed in the paper, and its application to hydrologic gauging is also briefly introduced.
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