Eigenvalue analysis for plain-woven fabric structure using shell element and one smoothing cell in the smoothed finite element method

An efficient four-node quadrilateral (Q4) shell element based on the first-order shear deformation theory of plate (FSDT) and the strain smoothing technique in finite elements (referred as SFEM) was proposed for eigenvalue analysis of plain-woven fabric structure. A one smoothing domain (or cell) integration scheme in SFEM was proposed to evaluate the nodal train fields of Q4 shell elements. The numerical result of eigenvalue analysis, which was in the case of free vibration analysis, approximated to that one implemented in the finite element method (FEM) but gave a higher efficiency in computation in terms of central processing unit (CPU) time and numerical implementation.The authors wish to express their acknowledgment to FCT funding from FCT – Foundation for Science and Technology within the scope of the project “PEST UID/CTM/00264; POCI-01-0145-FEDER 007136

Buckling analysis of plain-woven fabric structure using shell element and a one cell-based integration scheme in smoothed finite element method

A one smoothing cell integration scheme in the strain smoothing technique in finite elements (referred as SFEM) was proposed to evaluate the nodal train fields of a four-node quadrilateral (Q4) shell element, which is based on the first-order shear deformation theory of plate (FSDT). A mixed interpolation of tensorial components (MITC) approaches for Q4 transverse shear strains also applied to eliminate a shear locking phenomenon that may occur when the thin plate/shell elements are geometrically distorted in curved geometries of fabric sheet. The numerical eigenvalues of buckling analysis of a plain-woven fabric sample, of which physical and mechanical parameters extracted from Kawabata evaluation system for fabrics (KES-FB), obtained a higher efficiency in numerical computation and approximated to Q4 shell element implemented in the finite element method (FEM).The authors wish to express their acknowledgment to FCT funding from FCT – Foundation for Science and Technology within the scope of the project “PEST UID/CTM/00264; POCI-01-0145-FEDER 007136”

Practical use of reactor anti-neutrinos for nuclear safeguard in Vietnam

One of the most abundant man-made sources of low energy (few~MeVs) neutrinos, reactor neutrino, is not only useful for studying neutrino properties, but it is also used in practical applications. In this study, we investigate the practical use of reactor neutrino detectors for nuclear safeguard in Vietnam, specifically at the Dalat Nuclear Reactor, a future research facility, and presumably commercial reactors with 500~kW, 10~MW, and 1000~MW thermal powers, respectively. We compute the rate of observed inverted beta decay events, as well as the statistical significance of extracting isotope composition under the practical assumptions of detector mass, detection efficiency, and background level. We find that a 1-ton detector mass can allow us to detect the reactor's on-off transition state from a few hours to a few days, depending on the standoff distance and reactor thermal power. We investigate how background and energy resolution affect the precision of the extracted weapon-usable ${}^{239}\text{Pu}$ isotope. We conclude that in order to distinguish the 10\% variation of the ${}^{239}\text{Pu}$ in the 10~MW thermal power reactor, a 1-ton detector placed 50~m away must achieve 1\% background level. Increasing the statistics by using a 10x larger detector or placing it $\sqrt{10}$ times closer to the reactor alleviates the requirement of the background level to 10\%

A hybrid artificial neural network - genetic algorithm for load shedding

This paper proposes the method of applying Artificial Neural Network (ANN) with Back Propagation (BP) algorithm in combination or hybrid with Genetic Algorithm (GA) to propose load shedding strategies in the power system. The Genetic Algorithm is used to support the training of Back Propagation Neural Networks (BPNN) to improve regression ability, minimize errors and reduce the training time. Besides, the Relief algorithm is used to reduce the number of input variables of the neural network. The minimum load shedding with consideration of the primary and secondary control is calculated to restore the frequency of the electrical system. The distribution of power load shedding at each load bus of the system based on the phase electrical distance between the outage generator and the load buses. The simulation results have been verified through using MATLAB and PowerWorld software systems. The results show that the Hybrid Gen-Bayesian algorithm (GA-Trainbr) has a remarkable superiority in accuracy as well as training time. The effectiveness of the proposed method is tested on the IEEE 37 bus 9 generators standard system diagram showing the effectiveness of the proposed method

Stringent constraint on CPT violation with the synergy of T2K-II, NOν\nuA extension, and JUNO

Neutrino oscillation experiments have measured precisely the mass-squared differences of three neutrino mass eigenstates, and three leptonic mixing angles by utilizing both neutrino and anti-neutrino oscillations. The possible CPT violation may manifest itself in the difference of neutrino and anti-neutrino oscillation parameters, making these experiments promising tools for testing CPT invariance. We investigate empirically the sensitivity of the CPT test via the difference in mass-squared splittings ($\Delta m^2_{31} - \Delta \overline{m}^2_{31}$) and in leptonic mixing angles ($\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}$) with the synergy of T2K-II, NO$\nu$A extension, and JUNO experiments. If the CPT symmetry is found to be conserved, the joint analysis of the three experiments will be able to establish limits of $|\Delta m^2_{31} - \Delta \overline{m}^2_{31}|$ < $5.3\times 10^{-3} \text{eV}^2$ and $|\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}|$ < $0.10$ at 3$\sigma$ C. L. on the possible CPT violation. We find that with ($\Delta m^2_{31} - \Delta \overline{m}^2_{31}$), the dependence of the statistical significance on the relevant parameters to exclude the CPT conservation is marginal, and that, if the difference in the best-fit values of $\Delta m^2_{31}$ and $\Delta \overline{m}^2_{31}$ measured by MINOS(+) and NO$\nu$A persists as the true, the combined analysis will rule out the CPT conservation at 4$\sigma$ C. L.. With the ($\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}$), the statistical significance to exclude CPT invariance depends strongly on the true value of $\theta_{23}(\overline{\theta}_{23})$. In case of maximal mixing of $\theta_{23}$, the CPT conservation will be excluded at 3$\sigma$ C. L. or more if the difference in the best-fit values of $\theta_{23}$ and $\overline{\theta}_{23}$ remains as the true.Comment: 10 pages, 10 figure

A voltage electrical distance application for power system load shedding considering the primary and secondary generator controls

This paper proposes a method for determining location and calculating the minimum amount of power load needed to shed in order to recover the frequency back to the allowable range. Based on the consideration of the primary control of the turbine governor and the reserve power of the generators for secondary control, the minimum amount of load shedding was calculated in order to recover the frequency of the power system. Computation and analysis of the voltage electrical distance between the outage generator and the loads to prioritize distribution of the amount power load shedding at load bus positions. The nearer the load bus from the outage generator is, the higher the amount of load shedding will shed and vice versa. With this technique, a large amount of load shedding could be avoided, hence, saved from economic losses, and customer service interruption. The effectiveness of the proposed method tested on the IEEE 37 bus 9 generators power system standard has demonstrated the effectiveness of this method