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1 – 2 of 2Qing Xiao and Shaowu Zhou
Unscented transformation (UT) and point estimate method (PEM) are two efficient algorithms for probabilistic power flow (PPF) computation. This paper aims to show the relevance…
Abstract
Purpose
Unscented transformation (UT) and point estimate method (PEM) are two efficient algorithms for probabilistic power flow (PPF) computation. This paper aims to show the relevance between UT and PEM and to derive a rule to determine the accuracy controlling parameters for UT method.
Design/methodology/approach
The authors derive the underlying sampling strategies of UT and PEM and check them in different probability spaces, where quadrature nodes are selected.
Findings
Gauss-type quadrature rule can be used to determine the accuracy controlling parameters of UT. If UT method and PEM select quadrature nodes in two probability spaces related by a linear transform, these two algorithms are equivalent.
Originality/value
It shows that UT method can be conveniently extended to (km + 1) scheme (k = 4; 6; : : : ) by Gauss-type quadrature rule.
Details
Keywords
Chengcheng Luo, Shaowu Ning, Zhanli Liu, Xiang Li and Zhuo Zhuang
This paper aims to propose a design method for attenuating stress waves pressure using soft matrix embedded with particles.
Abstract
Purpose
This paper aims to propose a design method for attenuating stress waves pressure using soft matrix embedded with particles.
Design/methodology/approach
Based on the phononic crystal theory, the particle composed of hard core and soft coating can form a spring oscillator structure. When the frequency of the wave is close to the resonance frequency of the spring oscillator, it can cause the resonance of the particle and absorb a lot of energy. In this paper, the resonant phononic crystal with three phases, namely, matrix, particle core and coating, is computationally designed to effectively mitigate the stress wave with aperiodic waveform.
Findings
The relationship between the center frequency and width of the bandgap and the geometric and physical parameters of particle core are discussed in detail, and the trend of influence is analyzed and explained by a spring oscillator model. Increasing the radius of hard core could effectively enhance the bandgap width, thus enhancing the effect of stress wave attenuation. In addition, it is found that when the wave is in the bandgap, adding viscosity into the matrix will not further enhance the stress attenuation effect, but will make the stress attenuation effect of the material worse because of the competition between viscous dissipation mechanism and resonance mechanism.
Research limitations/implications
This study will provide a reference for the design of stress wave protection materials with general stress waves.
Originality/value
This study proposes a design method for attenuating stress waves pressure using soft matrix embedded with particles.
Details