Partial discharge (PD) measurement and recognition is of great importance to assess the health condition power transformers. However, variation defect size, applied voltage as well insulation aging gives rise dispersion crossover PD features, which would influence reliability An image-oriented two-directional modified fuzzy-weighted two-dimensional linear discriminant analysis (TD-MFW-2DLDA) for feature extraction gray images, aiming at solving above problem, proposed in this paper. Two...

The shear modulus is an essential parameter that reflects the mechanical properties of soil. However, little known about coral sand, especially under complex consolidation conditions. In this paper, we present results a multi-stage strain-controlled undrained cyclic test on saturated sand. influences several state parameters: effective mean principal stress (p0′), ratio (kc), direction angle (α0), and coefficient intermediate (b) maximum (G0), reference strain (γr) reduction (G) have been...

The liquefaction of saturated marine coral sand is a great issue for the safety ocean engineering. A series undrained cyclic torsional shear tests on are carried out to further explore characteristics sand. Based energy method, effects relative density (Dr), effective mean principal stress (p′0), and ratio (CSR) responses investigated. Two failure criteria discussed evaluate dissipated required cause initial (Wl). test results show that Wl significantly affected by Dr p′0. generation...

(1) Background: Spinal cord injuries and diseases necessitate sophisticated tools for accurate diagnosis treatment planning. However, the lack of reliable phantoms mimicking complex structure spinal hinders development validation advanced imaging techniques. This study aims to address this critical unmet need by exploring application electrospinning create polymeric fibers resembling human cord; (2) Methods: Direct jet coaxial (DJ-co-ES) is a specialized process characterized presence solely...

A projectile may be deformed and eroded due to the high pressure generated by hypervelocity penetration, which makes it difficult describe penetration mechanism for protection engineering existing theories at such velocities. To analyze depth of concrete-like targets subjected impact kinetic energy weapons, experiments with ogive-nosed steel projectiles penetrating mortar are conducted, where average uniaxial compressive strength is 41.8[Formula: see text]MPa velocities range from 1[Formula:...

In this paper, a graphics processing unit-accelerated smoothed particle hydrodynamics solver is presented to simulate the three-dimensional explosions in soils and their damage aluminium structures. To achieve objective, number of equations state constitutive models required close governing are incorporated into proposed framework, including Jones-Wilkins-Lee equation for explosive materials, Grüneisen metals, elastic-perfectly plastic model elastoplastic elasto-viscoplastic soils. The...

In welding, the arc welding images are always caused uncertain deformation and deflection due to of weldment. Therefore, image can not be corrected by traditional correction methods. Corresponding different qualities images, morphological characteristics decided factors welding. this paper, HU moment invariant theory is used reduce translation, scale variations which so on. First, extracting seven invariants pool image; second, constructing similarity parameter according invariants; finally,...

Abstract The prediction of the brisance performance aluminized explosive detonation, which involves complicated multiphase and multiphysics flow, is a difficult problem to tackle. In this paper, detonation HMX explosives investigated using density‐adaptive smoothed particle hydrodynamics methodology. ignition growth model was incorporated in calculate pressure generated by explosive, after‐burning combustion used obtain released energy caused aluminium particles. elastic‐perfectly plastic...

The P-α equation of state (EOS) and a nonlinear yield criterion are utilized to characterize the dynamic constitutive behavior concrete targets subjected projectile normal penetration. A cavity expansion model considering compressibility relations for material is developed. Then, theoretical calculate depth penetration (DOP) rigid established. Furthermore, proposed validated based on available test data as well calculation results by linear compressible EOS criterion. This study shows that...

Partial discharge (PD) diagnosis is confirmed to be one of the most effective tools for assessing health condition power equipment. Classification and recognition measured PD data provide insulation defects information which facilitate electrical apparatus. This paper presents a new group image features partial classification, where gray images are formed represent different defects. The decomposed into various vectors by two-dimensional linear discriminant analysis (2DLDA), 9 representative...

Ground loss due to earth pressure balance shield tunneling eventually leads a surface settlement which can be an issue of great concern. However, the existing machine learning methods ignore continuous and dynamic nature EPB tunneling. In this work, multivariate time‐series (MTS) model for ground is proposed based on analysis factors processes related combined with characteristics original data involving multiple parameters recorded by machines in real time. A method visualizing MTS features...

In the large-scale underground explosion, dynamic mechanical behavior of deep rock mass under coupled loading high in situ stress and explosive wave is difficult to study. And waves explosions are hard simulate. Based on this problem, an experimental device was developed, a nonexplosive method for simulating presented by us. device, impact energy provided high-pressure gas air chamber, generated piston, waveform adjusted composite pulse shaper. The can be transmitted container, where...

Abstract The integration of distributed power sources into the distribution network has transformed traditional radial topology structure a multi-source structure, which can lead to series problems, such as voltage violations and bidirectional flow in lines. This situation presents significant challenge protection technology. Therefore, based on electrical characteristics random loads sources, impact source fault is analyzed, adaptability different methods evaluated. Key factors for...

Partial discharge is an important characteristics of GIS insulation deterioration, and a comprehensive accurate analysis signal can identify the type defects, thus effectively preventing accidents improving equipment operating life. Accurate pattern recognition depends on effective feature extraction, however, there are many parameters, combining all them for will lead to dimensional disasters, fused features after dimensionality reduction may not be ideal. Fractal contain large amount data...

To study the theoretical calculation method of HEL for hard rock, major factors determining strength rock under dynamic loadings are firstly discussed. Secondly, is suggested based on Lundborg criterion, and parameters influencing analyzed Thirdly, obtained by calculation, numerical modeling, experiments compared. Fourthly, abnormal decreasing or increasing in plate impact explained. This research shows that increases with Poisson’s ratio, shear at zero pressure, coefficient internal...