In recent years, much attention has been paid to the application of high-speed centrifugal pumps; still, development this pump faces several challenges. order obtain a more comprehensive understanding pump, paper reviewed engineering application, technical challenges, and feasible solutions from aspects hydraulic design, including cavitation, excitation, efficiency issue at an ultra-low specific speed, solution these problems. The current state structural design was briefly described in...

The pressure fluctuations of high-speed centrifugal pumps are the hotspot in pump research. Pressure is differ for different structural designs and flow structures. High-speed usually designed to increase efficiency with an enlarged design at a low specific speed, which changes structure pump. In order analyze design, was measured, field simulated rates. Through analysis, we found that varied periodically consistent blade frequency. guide vane interference region were also closely related...

Suspension insulators are widely used in power systems to provide electrical insulation and mechanical support for high-voltage (HV) transmission lines. To detect replace the faulty on lines is of great importance safe operation system. A nontouch electric-field measurement method ceramic presented, which involves measuring points vicinity insulator strings calculating potential distribution along HV outdoor strings. It also suggests a way process influence from tower. The salient feature...

Aiming at the problems of traditional edge detection algorithms such as Sobel, Robert, Canny and Log etc. on noise immunity accuracy, this paper puts forward an algorithm which uses wavelet thresholding method to image denoising based generalized cross validation (GCV) first. Then go by using two-dimension (2-D) transform's mult-scale feature a`trous, selects result corresponds small-scale. Through comparison simulation results between improved method, performs better than detail reserving...

<b><i>Background:</i></b> Malignant cerebral infarction often occurs in patients with massive infarction. Monitoring brain edema is therefore helpful to make correct clinical decisions. Our previous studies have confirmed that electrical impedance (CEI) can sensitively reflect the after stroke. <b><i>Methods:</i></b> The CEI was measured consecutively by a noninvasive monitor 69 hemispheric (MHCI). results of were converted into perturbation...

Joint torque estimation is of great significance for the research and clinical application intelligent rehabilitation technology. This paper proposes a closed-loop model joint based on surface electromyography (sEMG). Combined with physiological characteristics muscle activation, nonlinear autoregressive eXogenous inputs(NARX) neural network sEMG signals established. In order to solve drift phenomenon estimation, state-space framework constructed by regarding NARX as state developing...

Multi-agent control is a central theme in the Cyber-Physical Systems (CPS). However, current methods either receive non-Markovian states due to insufficient sensing and decentralized design, or suffer from poor convergence. This paper presents Delayed Propagation Transformer (DePT), new transformer-based model that specializes global modeling of CPS while taking into account immutable constraints physical world. DePT induces cone-shaped spatial-temporal attention prior, which injects...

Nonlinear analysis of electroencephalogram (EEG) signals provides a means for studying the dynamical changes in cortical networks related to brain electrical activity. In this study, correlation dimension (D2) and point (PD2) were used investigate quantitative complexity EEG during cognitive processes. EEGs recorded 30 normal subjects under seven conditions: two resting states five mental activities. Results show that D2 PD2 are significantly correlated. Compared D2, is more sensitive data...

The slurry pump, which forms the core equipment of deep-sea mining (DSM) system, provides lifting power for ore from seabed to sea level, is crucial safety coarse particle transportation. Velocity slip plays a significant role in revealing migration pump particles. Therefore, this study analyzes velocity using computational fluid dynamics–discrete element method (CFD-DEM) first time. relationship between head and was proposed verified based on triangle Euler equation solid-liquid two-phase...

The special working condition of shore power cable is more likely to form a crack air gap in insulating medium, which will cause discharge. continuous discharge local temperature rising and stress concentrating, lead insulation deterioration. electro-t hermal-stress coupling method, this paper, used establish the finite element model cable. electric, field distribution for with medium also studied, correctness verified by experiments. In addition, paper investigated variation law ampacity...

Multi‐attribute clustering technology is an important approach for quantitative analysis on seismic facies. However, prior to facies analysis, in absence of the type and distribution data belt, interpreters have guess set cluster number manually, which brings great uncertainty sedimentary interpretation. How search inherent from effective solve problem. This paper presents PSO (Particle Swarm Optimization) — based multi‐attribute dynamic technology, a algorithm. During clustering, center can...

The number of cable loops in the tunnel is main factor that causes temperature rise and limits ampacity. In order to improve ampacity multi-loop tunnel, electromagnetic - thermal flow coupling calculation model was established based on ANSYS finite element simulation software. influence ventilation speed distance distribution studied, calculated according distribution. results show conductor decreases by less than 1°C for each 2m/s increase wind when more 6m/s. larger speed, smaller...

Heart rate variability (HRV) has become a useful tool for analyzing cardiovascular autonomic control from the electrocardiogram (ECG). Detection and analysis of HRV allows quantitative noninvasive method to obtain reliable reproducible information on modulation heart rate. Nonlinear methods (e.g., correlation dimension) are promising tools assessment. This paper presents estimation dimension (D/sub 2/) nonlinear analysis. A modified GP algorithm selection parameters presented. dynamical...

The accuracy of edge detection determines the actual dimension measurement，in order to improve measuring accuracy, this paper proposes a fast algorithm detecting glass bottle based on Zernike moments. Firstly, combines traditional moment-based method with Otsu adaptive threshold and new for is proposed. Then uses detect subpixel-level least square fit ellipses formed by mouth bottom. Calibrated system standard gauge block obtain at last. Experimental results show that improved not only can...

In this paper, an inversion method for fracture-related layer properties based on wide azimuth seismic data is presented. We first studied how the P-wave reflectivity between two HTI half-space media varies with angle of incidence and azimuth, which essential to parameterize main fracture orientation as a property. Then simplified linearized expression azimuthal derived by means reducing parameters changing variables. Finally, theory convolutional model, gather modeled, linear procedure...

On land seismic exploration, especially in areas of complex topography such as mountainous regions, foothills, and thrust belts, implementing FWI faces great challenges because this technique is required to accurately solve the wave equation with free-surface boundaries arbitrary shape effectively reconstruct a highly heterogeneous subsurface media. Conventional finite-difference-based (FDFWI) cannot be successful these challenging it always suffers from staircase effect inherent underlying...