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Non-Hermitian factors play a key role in introducing changes to the topology of acoustic systems, by significantly expanding the classification of topological phases beyond traditional Hermitian theory and presenting challenges to the conventional bulk–boundary correspondence. Traditional Hermitian theory cannot fully describe the complicated behavior of systems interacting with their environment, thus non-Hermitian theory emerged. Currently, most non-Hermitian topological systems derive their phases from Hermitian components, which entails concurrently considering the gain and loss of the system. In the study of higher-order topological insulators, higher-order topological states are usually achieved by modulating coupling strengths. While traditionally it is viewed that dissipation in topological systems is detrimental to the topological states, recent research studies have challenged this perspective. The nontrivial topology can arise by introducing loss of a specific configuration in a trivial phase. In this study, through finite-element simulations of coupled acoustic cavity systems from one-dimensional to three-dimensional structure, it is illustrated how intentionally introducing non-Hermitian loss can induce the higher-order topology. More crucially, we have simulated the acoustic local density of states (LDOS) and calculated fractional charge modes and can directly observe and prove through LDOS that introducing loss can convert a trivial system into a topological one. Both theoretical and simulated results show that the LDOS can be used to calculate fractional charge modes, effectively characterizing higher-order topological states in non-Hermitian acoustic systems. This study carves out a research pathway for the future of non-Hermitian acoustic topology. [ABSTRACT FROM AUTHOR]

This research examines the potential of digital twin (DT) technology for reformation within China's traditional solid-wood-panel processing industry, which currently suffers from production inefficiencies and the slow adoption of digital technology. The research centers around developing a digital twin system, elucidating improvements in manufacturing efficiency, waste management, process simulation, and real-time monitoring. These capabilities facilitate immediate problem solving and offer transparency in the process. The digital twin system is comprised of physical, transport, virtual, and application layers, employing a MySQL database and using the Open Platform Communications Unified Architecture (OPC UA) protocol for communication. The application of this system has led to heightened production efficiency and better material use in the solid-wood-panel manufacturing line. Integrating the dynamic selection adaptive genetic algorithm (DSAGA) into the virtual layer drives the system's efficiency forward. This evolved approach has allowed for an enhancement of 8.93% in the scheduling efficiency of DSAGA compared to traditional genetic algorithms (GAs), thereby contributing to increased system productivity. Real-time mapping and an advanced simulation interface have strengthened the system's monitoring aspect. These additions enrich data visualization, leading to better comprehension and a holistic process view. This research has ignited improvements in solid-wood-panel production, illustrating the tangible benefits and representing progress in incorporating digital technology into traditional industries. This research sets a path for transforming these industries into smart manufacturing by effectively bridging the gap between physical production and digital monitoring. Furthermore, the adjustability of this approach extends beyond solid-wood-panel production, indicating the capability to expedite movement towards intelligent production in various other manufacturing sectors. [ABSTRACT FROM AUTHOR]

Interrupted sampling repeater jamming (ISRJ) is a kind of coherent interference and its effect on radar signals is deceptive. To solve the high grating lobe problem formed by ISRJ through matched filtering, the waveform design method of low integrated sidelobe level (ISL) is studied. Considering the constant modulus constraint of the radar transmitting signal, the optimization problem is established by minimizing ISL as the objective function. Since the problem involves a nonconvex fourth-order objective and a nonconvex constraint, it is difficult to obtain a closed-form solution. Therefore, an accelerated majorization-minimization (MM) method is designed to solve the problem. Finally, compared with the existing algorithm, the simulation results show that the waveform designed can reduce the jamming's grating lobes and counter ISRJ effectively. [ABSTRACT FROM AUTHOR]

Background: Recently, there have been some reports of seizures related with COVID-19 vaccinations. However, no studies have systematically investigated the relationship between seizures and various COVID-19 vaccines., Research Design and Methods: This research aimed to analyze the characteristics and risk signals of new-onset seizures in children caused by various COVID-19 vaccines based on the data of the Vaccine Adverse Event Reporting System (VAERS). To identify potential risk signals, a disproportionality analysis was conducted. The reporting odds ratio (ROR) and the Proportional Reporting Ratio (PRR) were used to detect signals., Results: A total of 695 children with new-onset seizures events associated with COVID-19 vaccinations were retrieved from the VAERS database. Compared with influenza vaccinations, the percentage and rate of COVID-19 vaccinations related seizures was all reduced. The median onset time of seizures was 1 day after COVID-19 vaccines. No signal was detected for an association between the COVID-19 vaccines and new-onset seizures, neither when compared with influenza vaccines nor with non-COVID-19 vaccines., Conclusion: No statistically significant risk signal of COVID-19 vaccine-related seizures was found in this study. However, it is still necessary to monitor the possibility of new-onset seizures when children are immunized with COVID-19 vaccines.