Leaks in pipelines contribute to damping of transient events. That fact leads a method finding location and magnitude leaks. Because the problem flow pipes is nearly linear, solution governing equations can be expressed terms Fourier series. All components are damped uniformly by steady pipe friction, but each component differently presence leak. Thus, overall leak-induced divided into two parts. The indicates size leak, whereas different ratios various used find This does not require...

The effects of a partial blockage on pipeline transients are investigated analytically. A is simulated using an orifice equation, and the influence unsteady pipe flow considered in governing equations Dirac delta function. simplified, linear dimensionless equation has been derived, analytical solution expressed terms Fourier series developed under nonvarying boundary conditions. analysis indicates that friction both introduce damping fluid transients. exponential for each individual harmonic...

To explore the influence of water inflow on safe and efficient tunneling construction TBM in water-rich Luohe Formation sandstone. Based data at main inclined shaft site Kekegai Coal Mine, a relationship model between speed is established by using statistical analysis machine learning theory; XRD SEM tests microstructural components sandstone are carried out to analyze mechanism argillaceous cemented affecting TBM. The Libsvm support vector (SVR) more effective than multiple regression...

Abstract Feedforward control is one of the most effective techniques to increase robot’s tracking accuracy. However, dynamic models used in feedforward controllers are linearly simplified such that nonlinear and time-varying characteristics dynamics workspace ignored. In this paper, an iterative tuning method for parallel manipulators by taking into account proposed. Based on robot rigid-body model, a controller considering nonlinearity presented. An given iteratively update minimizing root...

Large Language Models (LLMs) have revolutionized natural language processing tasks. However, their practical application is constrained by substantial memory and computational demands. Post-training quantization (PTQ) considered an effective method to accelerate LLM inference. Despite its growing popularity in model compression, PTQ deployment faces two major challenges. First, low-bit leads performance degradation. Second, restricted the limited integer computing unit type on GPUs,...

Taking into account the inadequacy of Knothe time function model to predict dynamic surface subsidence caused by underground mining, a new hypothesis is proposed, and improved established. Theoretical analysis shows agrees well with change, velocity acceleration change rules. Combined field measured data, probability integral method, dual-medium least square method are adopted determine influence parameter C order n. Based on monitoring data from four stations in Guotun coal mine basin...

Abstract This paper presents a new design of high-static-low-dynamic stiffness (HSLDS) isolator with an adjustable cam profile. The interaction force between the and roller provides negative linear spring positive in HSLDS isolator. Unlike previous studies, profile this can be individually designed to meet different working conditions. Firstly, harmonic balance method is used acquire dynamic response Then, effects damping ratio, external amplitude on frequency transmissibility are discussed....

Vision-based measurement methods have attracted growing interests over the past years because of their non-contact sensing capability for acquiring full-field vibrations structure. Existing vision-based techniques, such as point tracking (PT) and digital image correlation (DIC), require preparation surface with high-contrast markers or speckle patterns before measurement. The phase-based motion magnification, enabling to extract vibration structure without pre-processing, is a newly...

Artificial ground freezing has been widely practiced in construction of metro cross passage soft ground. The process creats a frozen mass improved compressive strength and impermeability, which will make the safely stand by itself at point excavation prevent cave-ins from happening. With this technique, freeze pipes are arranged like stretchers half opened umbrella two ends passage. Usually finite element analysis on transient temperature field soil can simulate propagation wall (frozen...

Targeting the challenging analysis of temperature field artificial freezing shaft sinking projects in Cretaceous strata, this study used Hongqinghe air project as an example to perform a numerical simulation and measurement via method strata. First, thermal physical parameters mechanical properties frozen rock were measured lab. Based on engineering geological conditions test parameters, designed, preliminary scheme was obtained, which single ring holes arranged wall had design thickness 3.7...

We report a fiber optical parametric amplifier (FOPA) based on photonic crystal (PCF) with optimized dispersion and nonlinear properties pumped by mode-locked ytterbium-doped laser. Wavelength-tunable gain bands can be obtained adjusting the pump wavelength from anomalous to normal regime. By utilizing PCF-based FOPA, weak signals located in amplified. picosecond pulses generated at signal idler wavelengths. A 58-dB maximum wide bandwidth 999 1139 nm have been achieved pumping near...

Phase-based vibration measurement has attra- cted a lot of attention due to its advantages wireless, non-contact, and full-field capabilities. The phase shifts across the different video frames correspond motion structure, which makes it possible measure with phase. However, decoding presence singularities make phase-based method noise-sensitive non-robust when concerning measurement. Within this paper, an improved framework is proposed enhance performance technique for A double filtering...

Large Language Models (LLMs) have revolutionized natural language processing tasks. However, their practical application is constrained by substantial memory and computational demands. Post-training quantization (PTQ) considered an effective method to accelerate LLM inference. Despite its growing popularity in model compression, PTQ deployment faces two major challenges. First, low-bit leads performance degradation. Second, restricted the limited integer computing unit type on GPUs,...

Autonomous underwater vehicles (AUVs) are important tools for exploring and studying the ocean. To improve stealthiness of AUV positioning, a new type inverted ultra-short baseline (i-USBL) positioning system is proposed in this paper. The uses surface GPS buoy as base station to transmit signals AUV, which receives through i-USBL calculates its own coordinates. In way, power consumption will be lower, improving endurance. addition, azimuth observation one key quantities systems. Therefore,...

In pipeline irrigation system using pressurizing electromechanical pumps, the pumps usually work in constant speed under fundamental frequency power supply (50Hz) and operation characteristics of could not adapt to practical changes pipe network. When area is huge or gradient field high, requirement uniformity whole can be satisfied. Automatic water control graded pressure by variable combines conversion automation technologies, an integrated intelligent device with functions automatic...