Artificial ground freezing (AGF) has been applied widely in the construction of urban transportation infrastructure China for last two decades. This study provides a comprehensive review regional application, distribution, new developments, existing problems, and challenges AGF. The innovative achievements AGF theory technology are presented using selected prominent or typical engineering examples. Accidents problems occurring previous projects risks were analyzed. In addition, competition...

With the development of steel sheets towards higher strength and lower thickness, process rolling is facing more challenges, one most important issues lubrication, which directly determines stability, product quality, production efficiency. This study focuses on modeling analysis oil film thickness with viscosity–pressure–temperature (VPT) coupling effects under a hybrid lubrication system. Firstly, mechanisms limitations direct spray recirculation systems are systematically compared,...

In the production process of strip tandem cold rolling mills, flatness control system is important for improving quality. The efficiency actuators a pivotal factor affecting accuracy. At present, data-driven methods to intelligently identify have become research hotspot. this paper, wavelet transform longitudinal denoising method, combined with genetic algorithm (GA-WT), proposed handle big noise measured data from each signal channel meter, and Legendre orthogonal polynomial fitting...

Abstract Process monitoring and fault diagnosis systems are essential for ensuring the quality safety of industrial processes. Real process data always has dynamic features, autocorrelation non‐Gaussian distributions, making many multivariate statistical (MSPM) methods, such as principal component analysis (PCA), not work well. To solve problem, a new method (named DPCA‐ICA‐moving window Kolmogorov–Smirnov test [MWKS]) is proposed in paper, which combination DPCA independent (ICA) with...

Additive Manufacturing (AM) technology is widely used. There an increasing demand for quality of AM product. Currently, there no ideal method to monitor and ensure the during modeling process. In AM, model built layer by defects emerge gradually, so might not be found immediately manufacturing With accumulation inaccuracies, would decreased. To promote level control essential. this paper, Fused Deposition Modeling (FDM) studied combining Machine Vision (MV) Statistical Process Control (SPC)....

In order to overcome the shortages of diagnostic method for distribution networks considering reliability assessment, this paper proposed a based on power supply safety standards. It profoundly analyzed security standard urban networks, and established quantitative indicators load groups different fault conditions. Then suitable evaluation in China was given. method, “N-1” calibration analysis network conducted. results are compared with conditions deriving conclusions revision is discussed....

One of the most important lessons learned from Alaska's major earthquakes is that lateral spread frozen ground crust overlying liquefiable soils induced extensive bridge foundation damage. A shake table experiment was performed to study interaction mechanisms soil-pile in this scenario. Data collected were presented and analyzed. Three plastic hinges formed on model pile: one at surface, crust-loose sand interface by strong confinement stiff crust, within partially liquefied medium dense...

The high-frequency signal injection method has been proved as a practical technique to estimate the rotor position for PMSM. However, it becomes an additional issue that deserves investigation improve detection accuracy. In this paper based on fundamental is presented and its defects are analyzed. A special processing implemented demodulate which contains information. improved approach with demodulation technique, can effectively inhibit nonlinear distortion caused by inverter delay filter, proposed.

A loss minimization strategy for PMSMs used EVs is proposed in this paper which based on PMSM-DTC model. Through the analysis of relationship between kinds losses and exciting current, optimal given values are obtained. The control principles stator flux, torque angle system analyzed to propose a voltage vector selection twelve sectors substituting traditional switching table. results verify that can improve efficiency system, decrease current ripples, dynamic static performance system.

Recently, the directional drilling technology (DDT) has been extensive used in many energy field such as coal geological exploration, gas drainage and artificial freezing engineering etc. The theoretical model of trajectories is insufficient leading to control almost uncertain. In present study, a proposed, which simplified combination alternants constant curvatures smoothing quasi-helical segments. essential condition nonlinear piecewise systems proved by maximal principle. Multimodal...

An efficiency optimization method of permanent magnet synchronous machine for electric vehicles applications is researched.Considering iron loss equivalent resistance and direct torque control scheme, the relationship stator flux power derived based on model.And then real-time optimal target can be obtained through d-axis flux, speed at minimum situation.A fitting curve versus by simulation.This makes closer to actual value compared with fixed value.Simulation results show that motor has...

In this paper, numerical predictions of ship motions and added resistance in regular head waves by solving the unsteady Reynolds average Navier-Stokes (RANS) equations with a shear-stress transport (SST) K-ω turbulence model is presented. Volume fluid method (VOF) applied for treatment free surface. The Wigley III has been computed using RANS solver Fluent. simulations have carried out to measure heaving pitching which covered seven different wavelengths. Froude number hull are 0.2, 0.3 0.4....

He, X.; Zhou, Xu, Y.; Ma, W., and Wu, T., 2020. Study on the influence of nonlinear seepage grouting reinforcement surrounding rock in subsea tunnel. In: Liu, X. Zhao, L. (eds.), Today's Modern Coastal Society: Technical Sociological Aspects Research. Journal Research, Special Issue No. 111, pp. 162–167. Coconut Creek (Florida), ISSN 0749-0208.Seepage is an important problem tunneling engineering, which shows characteristics low permeability media. Particularly seabed environment, Darcy's...