The conventional methods of attribute extraction and calculation have many limitations for complex low level faults. Therefore, we propose a new method of seismic attribute extraction based on the rhombus that can be arbitrarily rotated and regulated its axis which achieves a satisfactory result on the application of fault identification. Research shows that: 1) the attributes extracted by rotating rhombus have better ability of direction identification, and it is particularly suit to identify the fault and fracture zone; 2) the attribute extracted by rotating rhombus its major to minor axis ratio is 5:2 has the best resolution; 3) we can extract a variety of amplitude and energy attributes by using the method, among which the total absolute amplitude attribute or total energy attribute is better for fault description; 4) our method has a good noise immunity, which can extract accurate direction attribute if the SNR is greater than 1, which can completely fulfill the require of data interpretation; 5) the method can also be used to quantitatively identify the shattered fault zones.
Based on the first order velocity-stress scheme on staggered grids, a three dimensional (3-D) finite-difference time-domain (FDTD) is applied to numerical study the designing of isolator of Logging-While-Drilling (LWD) acoustic tool in cylindrical coordinates. Simulation results show that different periodic grooved isolators vary widely in delaying and attenuating the tool waves which propagate along the tool. A type of isolator with staggered grooves is proposed for better performance.
The growing demands for high level of energy efficiency have given much new impetus to the development of electric vehicle in Agricultural Machines. To improve the performance of the state observer for an 8-DOF four-wheel vehicle, a state observer based on the Extended Kalman Filter is proposed. With the observer, the tire-road forces and the vehicle roll velocity are estimated accurately according to the simulation results. With the consideration of the nonlinear characters of tire and electric vehicle, the electronic differential controller is proposed to select the wheel slip ratios as the control tracking variables and distribute the torques to ensure the steering stability by using modified exponent approaching sliding mode control method. The proposed electronic differential controller is robust to improve the handling performance and control response of electric vehicle with the numerical verification.
The MP-PIC CPFD method was used to numerically simulate the particle flow in a moving bed, and the change of particle outlet flow under different discharge slope of the moving bed was studied, so as to select the appropriate discharge slope of the moving bed. The results show that when the discharge slope is 45 degrees, compared with the discharge slope of 30 degrees, the outlet flow is more stable, and the mass flow of 60 degrees is larger. In the unloading process with a calculated time of 30s, the cumulative discharge quality of the moving bed with a 30 degree and 45 degree discharge slope is similar, while the discharge quality of the moving bed with a 60 degree discharge slope is 116% of that of the other two moving beds. It can be concluded that the discharge slope of the moving bed at 45 degrees can ensure the good flow uniformity of the moving bed and the good flow uniformity of the moving bed. Through the three-dimensional numerical simulation of the moving bed, the theoretical basis for the structural design of the moving bed is provided.
Fuel-flexible hydrogen generation methods, such as electrochemical conversion of waste biomass, offer a route to sustainable production of hydrogen (in addition to steam or water electrolysis using renewable electricity [1]) whilst valorising feedstocks that are often overlooked. [2] In this research, the authors explore the potential of a novel, two-stage electrolysis process to convert biomass-containing solid and liquid distillery waste products into hydrogen, using a phosphomolybdic acid (H 3 [PMo 12 O 40 ] or PMA) catalyst, at lower operating voltages (<0.95 V) than proton exchange membrane (PEM) water electrolysers (1.5 – 1.6 V). [3] Firstly, an overview of the processes, energy usage and waste stream generation at the Isle of Raasay Distillery (Hebrides, Scotland) will be provided, before results from the characterization of whisky waste products are introduced. This provides a detailed compositional analysis of both solid (draff/spent barley) and liquid (pot ale and spent lees) wastes, as well as residual alcohol analysis of the liquid wastes, and their potential for conversion to hydrogen. Subsequently, the concept of thermal digestion of each waste-type, using the Keggin-type polyoxometalate PMA catalyst to abstract protons and electrons from biomass, will be outlined. Finally, details of electrolysis of the PMA-biomass solutions using a PEM flow cell will be provided, including electrochemical data (AC impedance spectroscopy, linear sweep voltammetry and potentiostatic operation) in order to determine the optimal operating conditions for the process, in addition to the respective yield of hydrogen from each biomass source. Prospects for upscaling the process will also be discussed. References Götz, M., Lefebvre, J., Mörs, F., McDaniel Koch, A., Graf, F., Bajohr, S. Reimert, R. and Kolb, T., Renew. Energ ., 85 , 1371 – 1390 (2016). Liu, W., Cui, Y., Du, X., Zhang, Z., Chao, Z. and Deng, Y., Energy Environ. Sci. , 9 , 467 – 472 (2016). Oh, H., Choi, Y., Shin, C., Nguyen, T. V. T., Han, Y., Kim, H., Kim, Y. H., Lee, J-W., Jang, J-W. and Ryu, J., ACS Catal. 10 , 2060 – 2068 (2020).
The uneven distribution of loading, the clamping damage and the stress concentration were thought to be the three key factors influencing the fatigue test of steel strand with pulsating tensile load. To these three influence factors, the improving measure and the test method have been proposed correspondingly, and a set of doubly piled clamping apparatus also has been designed, under which the fatigue test was carried out successfully at higher level of stress.
Segment Anything Models (SAMs) are extensively used in computer vision for universal image segmentation, but deploying them on resource-constrained devices is challenging due to their high computational and memory demands. Post-Training Quantization (PTQ) is a widely used technique for model compression and acceleration. However, existing PTQ methods fail to consider the cross-attention architecture in the SAM decoder. This degradation primarily stems from the unique challenges posed by SAMs: (1) Attention dissipation, where the attention information in the decoder, which is crucial for representing segmentation masks, collapses into a diffuse and non-semantic form under low-bit quantization; and (2) Reconstruction oscillation, where bidirectional coupling within the two-way transformer introduces cross-branch error interference and destabilizes convergence. To tackle these issues, we propose CAR-SAM, a unified quantization framework tailored for SAMs. Firstly, to mitigate attention dissipation, we introduce MatMul-Aware Compensation (MAC) mechanism that transfers activation-induced quantization errors from MatMul to preceding linear weights. Secondly, to mitigate oscillation in decoder optimization, we develop a Joint Cross-Attention Reconstruction (JCAR) strategy that jointly reconstructs coupled attention branches, suppressing oscillatory behavior and promoting stable convergence. Extensive experiments show that CAR-SAM robustly quantizes SAM models down to 4-bit precision, surpassing existing methods by 14.6% and 6.6% mAP on SAM-B and SAM-L respectively.
