Good Synchronization Research Articles

Applied experimental research on in-situ online monitoring instrument for soil radon in fault zone

As an emerging method for seismic precursory signals in underground fluid, the reliability and stability of in-situ online monitoring devices for soil radon are crucial performance indicators that are directly related to the successful implementation of continuous monitoring of soil radon in seismic areas. This study conducted laboratory testing and field applications of a new in-situ online monitoring instrument for seismic soil radon, utilizing the experimental testing conditions provided by the radon monitoring instrument detection platform of the China Earthquake Administration and the natural experimental site at Xianshuihe Fault Zone in the China Seismic Experimental Site. The results indicate that laboratory measurement repeatability of the instrument is 5.53%, the relative intrinsic error of radon volume response activity is 1.53%, and the response capability of hourly sampling at high radon volume response activity (greater than 1.0 × 105 Bq/m3) lags behind the standard instrument by 2 h, essentially meeting the requirements for seismic observation. Under field conditions, the instruments exhibit good synchronization in response at different depths at the same location. However, further improvements are needed to enhance the consistency of long-term operation in the field, as well as the adaptability to outdoor self-powering, data transmission, and environmental conditions.

Research on tracking and synchronization control of dual hydraulic cylinders based on improved active disturbance rejection control

To ensure the stability of vertical mold casting machine casting, and improve the quality of casting, for which the electro-hydraulic servo system of the traditional active disturbance rejection control(ADRC) of the nonlinear function is not smooth, a new type of nonlinear function is used. For the ADRC controller, there are too many adjustment parameters and complex engineering tuning, The snake optimization(SO) algorithm is used to adaptively tune the controller parameters, and the error can also be reduced. The simulation results show that compared with the PID controller and the traditional ADRC controller, the ADRC controller based on the Ifal function and SO has a certain jitter suppression effect as well as good tracking and synchronization performance, which can effectively improve the tracking and synchronization accuracy of the dual hydraulic cylinders of the electro-hydraulic servo system.

High-power single-frequency continuous-wave 355 nm UV laser via a frequency-correlated dual-wavelength laser.

An all-solid-state single-frequency continuous-wave (CW) 355 nm ultraviolet (UV) laser based on a dispersion-compensated doubly resonant resonator is presented in this Letter that is achieved by employing homemade high-stability all-solid-state frequency-correlated dual-wavelength lasers at 1064 and 532 nm and a temperature-controlled type-I critical-phase-matching LiB3O5 (LBO) to act as the fundamental laser source and the nonlinear medium, respectively. The frequency-correlated dual-wavelength single-frequency CW laser supplies the fundamental frequency 1064 and 532 nm lasers with good frequency synchronization. And the temperature-controlled LBO acts as the dispersion-compensation element to realize double resonance of the 1064 and 532 nm laser. Finally, a 4.2 W high-stability 355 nm UV laser is experimentally obtained, and the corresponding total conversion efficiency is up to 20.5%. To the best of our knowledge, this is the highest power reported about single-frequency CW 355 nm UV laser. The presented method can pave a way to develop a compact single-frequency 355 nm UV laser with high output power.

Running safety control performance of high-speed trains on bridges under seismic excitation utilizing tuned mass damper

The safety of high-speed trains on bridges during seismic conditions is of paramount concern, especially for high-pier bridges characterized by lower lateral stiffness. The risk of train derailment during earthquakes can increase due to heightened low-frequency excitation. While Tuned Mass Dampers (TMDs) have proven effective in mitigating structural responses, their influence on time-varying vehicle-bridge interactions under earthquakes remains an unexplored area of study. In this research, a 1:10 scale model of a high-speed train-track-bridge coupling system, incorporating a nonlinear wheel-rail interface, was subjected to testing using a four-shaking-table system. This system exhibited good control accuracy and synchronization rates. The experimental results were used to validate the accuracy of the numerical model for the train-track-bridge coupled system under various train speeds. Subsequently, the seismic control performance of TMDs on high-speed trains was assessed through a combination of experimental tests and numerical simulations. Both sets of results, from the experimental and numerical approaches, confirmed the effectiveness of TMDs in controlling acceleration and force-related parameters for both moving and stationary trains. Notably, the control performance is most pronounced when vibrations closely align with the TMD's operating frequency. Additionally, this study delved into the mechanism of train vibration control and conducted a comprehensive parametric investigation, considering factors like pier heights (24 m–50 m), train speeds (0–300 km/h), ground motion intensities (0.04 g–0.21 g), and TMD mass ratios (0.03–0.08). The findings revealed that TMDs have a more significant impact on enhancing the safety index of trains for high-pier bridges characterized by lower frequencies. For instance, in the case of a 50 m pier, the running train's derailment coefficient can be reduced by 34.94 %. However, the control action is narrowband, effectively mitigating train vibrations near the bridge's natural frequency but less effective outside the working frequency range and absolute base acceleration.

Plasmoid drift and first wall heat deposition during ITER H-mode dual-SPIs in JOREK simulations

The heat flux mitigation during the thermal quench (TQ) by the shattered pellet injection (SPI) is one of the major elements of disruption mitigation strategy for ITER. It’s efficiency greatly depends on the SPI and the target plasma parameters, and is ultimately characterised by the heat deposition on to the plasma facing components. To investigate such heat deposition, JOREK simulations of neon-mixed dual-SPIs into ITER baseline H-mode and a ‘degraded H-mode’ with and without good injector synchronization are performed with focus on the first wall heat flux and its energy impact. It is found that low neon fraction SPIs into the baseline H-mode plasmas exhibit strong major radial plasmoid drift as the fragments arrive at the pedestal, accompanied by edge stochasticity. Significant density expulsion and outgoing heat flux occurs as a result, reducing the mitigation efficiency. Such drift motion could be mitigated by injecting higher neon fraction pellets, or by considering the pre-disruption confinement degradation, thus improving the radiation fraction. The radiation heat flux is found to peak in the vicinity of the fragment injection location in the early injection phase, while it relaxes later on due to parallel impurity transport. The overall radiation asymmetry could be significantly mitigated by good synchronization. Time integration of the local heat flux is carried out to provide its energy impact for wall heat damage assessment. For the baseline H-mode case with full pellet injection, melting of the stainless steel armour of the diagnostic port could occur near the injection port, which is acceptable, without any melting of the first wall tungsten tiles. For the degraded H-mode cases with quarter-pellet SPIs, which have 1/4 total volume of a full pellet, the maximum energy impact approaches the tolerable limit of the stainless steel with un-synchronized SPIs, and stays well below such limit for the perfectly synchronized ones.

Sequential Data-Based Fault Location for Single-Line-to-Ground Fault in a T-Connection Power Line

Due to the demand for temporary rapid grid connection in renewable energy power plants, the topology structure of T-connected power lines has been widely used in the power grid. In this three-terminal system, fault localization is difficult because of traditional impedance-based or traveling wave-based fault localization methods; the three-terminal data should be synchronized and communicated. Since different terminal assets belong to different enterprises, it is actually difficult to maintain good synchronization between them. Therefore, in practical applications, the fault location of T-connected power lines often fails. This article proposes a single terminal fault location method for a T-connection power line to address this issue. It is based on the fact that the local topology of the T-connected power line in the healthy phase remains unchanged during the fault-clearing process. It utilizes the sequential current and voltage data changes generated by the sequential tripping ping emitted by the circuit breaker from different terminals to describe the constant topology of the healthy phase as an equation and calculates the accurate fault location after solving the equation. The Levenberg–Marquardt algorithm was used to calculate fault distance and transition resistance, and the effectiveness of this method was verified through simulation.

Optical chaos synchronization in a cascaded injection experiment.

We experimentally study the synchronization of chaos generated by semiconductor lasers in a cascade injection configuration, i.e., a tunable master laser is used to generate chaos by optical injection in a transmitter laser that injects light into a receiver laser. Chaos synchronization between the transmitter and the receiver lasers is achieved with a correlation coefficient of 90% for a measurement bandwidth up to 35 GHz. Two parameter regions of good synchronization are found, corresponding to the alignment of the oscillation frequencies of the receiver laser with either the transmitter laser or the master laser.

Interannual synchronization of the North American summer monsoon and the North Atlantic tropical cyclone genesis frequency

Variations of the North American summer monsoon (NASM) and North Atlantic tropical cyclone (NATC) activities strongly influence climate anomalies in North America, with serious potential risk to life and property. Despite the scientific importance of this topic, the possible linkage between the NASM and the NATC genesis frequency remains unexplored. Here, we aim to examine the relationship between interannual variations of the NASM intensity and the NATC genesis frequency based on observations and Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Our results show a strong association between the NASM intensity and the NATC genesis frequency during the extended boreal summer, with a good synchronization between their interannual variations. In years with stronger (weaker) NASM intensity, the NATC genesis frequency tends to be higher (lower). The observed NASM–NATC synchronization may be explained by two pathways: tropical-ocean-driven pathway and monsoon-heating-driven pathway. In the tropical-ocean-driven pathway, the tropical Pacific and Atlantic interbasin sea surface temperature (SST) anomalies play a critical role in bridging the NASM and NATC, by modulating the cross-Central American wind. Simulations of the tropical Pacific–Atlantic interbasin SST anomalies are critical for CMIP6 models to capture the observed linkage between the NASM and the vertical wind shear over the NATC main development region (MDR). In the monsoon-heating-driven pathway, the heating source due to the rainfall anomalies associated with the NASM can trigger atmospheric circulation anomalies through the Gill-type response, thereby affecting the NATC by changing the vertical wind shear over the MDR. This study demonstrates a connection between interannual variations of the NASM and the NATC genesis frequency, results of which can be used to advance our understanding of the monsoon–TC relationship and increase research focus on the interannual NASM–NATC synchronization in climate prediction.

Chaotic control problem of BEC system based on Hartree–Fock mean field theory

Abstract Due to the difficulty of studying nonlinear quantum systems and the unique composition of Bose–Einstein condensate (BEC) systems, BECs face significant difficulties in solving dynamic analysis and chaotic control problems. Therefore, Hartree–Fock mean field theory is introduced to study the chaotic characteristics, control, and synchronization issues of BEC systems loaded on optical lattices. First, the stability and chaos of BECs in optical lattices were analyzed. Subsequently, constant shift method and activation control were introduced based on the Gross–Pitaevskii equation to achieve control and synchronization of the BEC system. Second, based on the Lyapunov exponent theory, offset parameters are added to BEC chaotic control to achieve control of particle density. Finally, based on the stability theory of linear systems, a control term is introduced to achieve variable analysis of the system’s drive–response system, ensuring that chaotic systems with different initial conditions can still achieve good synchronization and anti-synchronization control. The chaotic problem of BEC system was analyzed using numerical and theoretical methods in the experiment. The effect of adjusting the parameters of the BEC system under the constant shift method is significant. The system exhibits a chaotic state under the Lyapunov exponent, which is mainly concentrated between [3.4, 4.5], demonstrating good system stability. When the offset constant range is [4.21, 5.67], the maximum Lyapunov exponent value is below 0. In the problem of chaotic synchronization, adding activation control causes the system’s time series to exhibit anti-synchronization with spatiotemporal variable variation, while adding control terms leads the system to tend towards synchronization and anti-synchronization with time evolution. The analysis of chaotic control problems in BEC systems can provide reference value and theoretical basis for the dynamic research of quantum physics and related nonlinear systems.

Sensitivity Options of 5G Non-Standalone Deployment Strategies: A Simulation Model for Emerging Countries

Deploying cutting-edge 5G technology is a major challenge for mobile operators in emerging countries, facing hurdles on both the technical and economic fronts. This study provides specific ways in which mobile companies in developing countries can use 5G technology to benefit economically. This study utilizes a sensitivity option with a techno-economic analysis (TEA) simulation model to evaluate business options influencing successful 5G non-standalone (NSA) deployment in these markets, using Indonesia’s Bandung City as a case study. The analysis finds that Bandung requires 172 5G gNodeBs to meet traffic demand. Further, the 5G NSA deployment delivers strong key performance indicators (KPIs), with good signal synchronization received power (SS-RSRP) and signal-to-interference noise ratio (SS-SINR). Sensitivity analysis identifies the gNodeB amount as the most critical parameter impacting overall 5G NSA deployment feasibility. Overall, the analysis indicates mobile operators can recover investments after 3 years and 10 months, providing evidence for the viability of 5G NSA deployment in Bandung’s urban area.

Comparison of Reproductive Strategies between Two Sympatric Copsychus Passerines.

Reproduction plays a crucial role in determining the development, fate, and dynamics of bird populations. However, reproductive strategies vary among species and populations. In this study, we investigated the reproductive strategies of the Oriental Magpie Robin (Copsychus saularis) and White-rumped Shama (C. malabarica), which are closely related passerines that reproduce in sympatric areas. We found that although these two species were both cavity nesting, their nest-site selection differed; the Shama preferred nesting close to trees and forests, whereas the Magpie Robin nested close to human residential areas. Furthermore, their egg incubation patterns differed; the Shama increased daily incubation frequency with incubation time, but the Magpie Robin maintained its daily incubation time regardless of changes in incubation frequency. However, the nestling heating patterns of these two species were similar, indicating a critical demand for regulating hatchling body temperature during this crucial stage. The feeding frequencies of male parents were strongly correlated with those of females in both species, suggesting equal contribution and good synchronization between the sexes. Nestling feeding frequency was also correlated with nest cleaning frequency, implying coordination between feeding and defecation by parents and offspring, respectively. This research explored the divergence and convergence of reproductive strategies between these two sympatric species, providing valuable insights into the niche differentiation theory.

Monitoring damage of concrete beams via self-sensing cement mortar coating with carbon nanotube-nano carbon black composite fillers

Self-sensing concrete used in coating form for structural health monitoring of concrete structures has the merits of cost-effectiveness, offering protective effect on structural components, enabling electrical measurements unaffected by steel reinforcement and is also convenient to maintain and replace. This paper investigates the feasibility of using self-sensing cement mortar coating containing carbon nanotube-nano carbon black (CNT-NCB) composite fillers (CNCFs) for damage monitoring of concrete beams. The self-sensing cement mortar coated to concrete beams demonstrated outstanding electrical conductivity (resistivity ranging from 18 to 85 Ω·cm). Under monotonic flexural loadings, self-sensing cement mortar coating with 1.8 vol.% CNCFs featured sensitive self-sensing performance in terms of capturing the initiation of vertical cracks at pure bending span of concrete beams, with fractional change in resistivity (FCR) reaching up to 60.6%. Moreover, FCR variations of self-sensing cement mortar coating exhibited good synchronization and stability with the variation of mid-span deflections of concrete beams during cyclic flexural loadings irrespective of the contents of CNCFs and cyclic amplitudes. Remarkably, it was found that FCR of cement mortar coating basically showed a progressive upward tendency, representing irreversible increase in the resistance during cyclic loading. The irreversible residual FCR indicated the crack occurrence and damage accumulation of concrete beams.

Feasting on the ordinary or starving for the exceptional in a warming climate: Phenological synchrony between spongy moth (Lymantria dispar) and budburst of six European tree species.

Global warming is affecting the phenological cycles of plants and animals, altering the complex synchronization that has co-evolved over thousands of years between interacting species and trophic levels. Here, we examined how warmer winter conditions affect the timing of budburst in six common European trees and the hatching of a generalist leaf-feeding insect, the spongy moth Lymantria dispar, whose fitness depends on the synchrony between egg hatch and leaf emergence of the host tree. We applied four different temperature treatments to L. dispar eggs and twig cuttings, that mimicked warmer winters and reduced chilling temperatures that are necessary for insect diapause and bud dormancy release, using heated open-top chambers (ambient or +3.5°C), and heated greenhouses (maintained at >6°C or >10°C). In addition, we conducted preference and performance tests to determine which tree species the larvae prefer and benefit from the most. Budburst success and twig survival were highest for all tree species at ambient temperature conditions, whereas it declined under elevated winter temperature for Tilia cordata and Acer pseudoplatanus, likely due to a lack of chilling. While L. dispar egg hatch coincided with budburst in most tree species within 10 days under ambient conditions, it coincided with budburst only in Quercus robur, Carpinus betulus, and, to a lesser extent, Ulmus glabra under warmer conditions. With further warming, we, therefore, expect an increasing mismatch in trees with high chilling requirements, such as Fagus sylvatica and A. pseudoplatanus, but still good synchronization with trees having low chilling requirements, such as Q. robur and C. betulus. Surprisingly, first instar larvae preferred and gained weight faster when fed with leaves of F. sylvatica, while Q. robur ranked second. Our results suggest that spongy moth outbreaks are likely to persist in oak and hornbeam forests in western and central Europe.

The influence of operation times of manual tamping device on ballast bed state

The manual tamping device plays an important role in the daily maintenance and repair of ballasted track. It is difficult to establish a suitable analytical model for manual operations because of their inherent flexible characteristics. There is a lack of sufficient theoretical research on daily maintenance and repair which are mainly based on the long-term field experience of workers. For guiding the field operation of manual tamping devices, a coupled simulation model of impacted manual tamping device and ballasted track was established based on the DEM-MBD coupling method. The proposed model effectively simulated the manual tamping operations. The correctness of the model was verified through field lateral resistance tests. The proposed coupling model was applied for computing the change in the support stiffness of the ballast bed under different tamping times. Further analysis was done to study the impact of manual tamping operations on the contact force and movement of the ballast. The results show that the vibration and impact of the manual tamping device have changed the original contact relationship between the ballast particles. The attenuation amplitude of the support stiffness of the ballast bed initially decreased and later increased with increase in tamping times, resulting in the ballast bed with higher initial stiffness more elastic. A similar trend and good synchronization were observed between the average contact force and angular velocity between ballast particles with manual tamping time, resulting in improved compactness and stability of the ballast bed. And it is recommended to perform tamping five times for optimal results.

Time calibration and synchronization of the scintillation light detection system in ICARUS-T600

The ICARUS-T600 Liquid Argon (LAr) Time Projection Chamber (TPC) is presently taking data in the Short Baseline Neutrino (SBN) program at Fermilab (U.S.A.) to search for a possible LSND-like sterile neutrino signal at Δm 2 ≈ 1 eV2 with the Booster Neutrino Beam (BNB). A light detection system, based on 360 large area Photo-Multiplier Tubes (PMTs), has been realized for ICARUS-T600 to detect VUV photons produced by the passage of ionizing particles in LAr. This system is fundamental for the TPC operation, providing an efficient trigger and contributing to the 3D reconstruction of events. Moreover, since the detector is exposed to a huge flux of cosmic rays due to its shallow depths installation, the light detection system allows for the time reconstruction of events, contributing to the identification and to the selection of genuine neutrino interactions. The correct time reconstruction of events requires the precise knowledge of the delay of each PMT channel and a good synchronization of recording electronics, this last based on fast sampling digitizers. To achieve a time resolution better than 1 ns, we perform three consecutive timing corrections deployed at different stages of the optical data flow. Results demonstrate the capability of the ICARUS-T600 light detection system to allow a precise reconstruction of the temporal evolution of each event occurring in the detector and the association of neutrino events with the bunched structure of BNB.

Synchronization of complexity enhanced chaos in semiconductor lasers

In synchronized chaotic lasers based secure key distribution and other encrypted communications, presence of the time delay signature in chaos poses a threat to security. So the transmitter and receiver lasers should preferably be operated in complexity enhanced chaotic regime where the time delay signature is hidden. However, achieving good synchronization in experiments in such regime is challenging. We report experimental demonstration of achieving excellent synchronization between two semiconductor lasers even when both the lasers are operating in complexity enhanced chaotic regime with absolutely no time delay signature present in their output. This chaotic regime is ensured by evaluating the auto correlation function, permutation entropy and spectrum analysis of the time series. As a measure of synchronization, cross-correlation coefficient of 0.923 is achieved between the transmitter and receiver lasers. This results are of immense importance in chaos based secure key distribution and other encrypted communication schemes.

The Early Warning System in Preventing Human Trafficking: Border (In) Security and Challenges for Indonesia

This article aims to find out how the early warning system is constructed in detecting human trafficking. This research discusses human trafficking in Indonesia, where most of the victims were trafficked to neighboring countries in the border area. One of the unsolved problem exist today is human trafficking in frontier areas; hence, there are three major factors causing the number of human trafficking in Indonesia is in high level according to data from the International Organization for Migration. This article is using empirical legal research method. The results show that the construction of an early warning system can be formed by studying the methods or modes used by the perpetrators in committing the crime of human trafficking. However, for this concept to succeed, good synchronization is needed between filters that include potential victims, agencies or institutions that can represent administrative functions, and officers at border area guard posts.

Solid-state Marx generator based on saturable pulse transformer and fast recovery diodes

Solid-state compact Marx generator using saturable pulse transformer (SPT) and fast recovery diodes has been proposed. The primary circuit is switched by three MOSFETs connected in parallel. The SPT functions as a step-up transformer to increase the voltage amplitude and as a closing switch for the secondary circuit. Meanwhile, all the SPTs share the same magnetic core to achieve a compact structure and ensure good synchronization. The energy storage capacitors on the secondary sides are charged through the unsaturated SPT. When the SPT saturates, the capacitors firstly transfer a little energy to the saturated inductors through the diodes reversely during their reverse recovery process. Currents rise quickly in these inductors until diodes totally recover to reverse blocking state. Then capacitors discharge in series to the load and high-voltage pulses are generated over the load. With the currents in the saturated inductors, the front edges of pulses are no longer affected by them but are dominated the turn-off speed of the diodes, which makes high-voltage and high-current pulses with short front edges possible. The regular and cheap fast recovery diodes in the generator act as semiconductor opening switch to sharpen the pulse front edges. Experiments were carried out with a 4-stage Marx generator prototype, 10.8-kV high-voltage pulses with a front edge of 11 ns, a pulse width of 190 ns, were obtained over a 100-Ω resistive load. The total energy efficiency is 49.8%. The proposed Marx generator using regular fast recovery diodes is compact, cheap, and efficient to generate high-voltage pulses with short front edges.

Identifying asynchronies: Expiratory work

Mechanical ventilation is used to improve gas exchange and unload the respiratory muscles allowing for their rest and recovery, which require good synchronization between the patient and the ventilator. Spontaneous respiratory effort is generally preferred because it reduces atelectasis, improves oxygenation, and may prevent disuse diaphragm atrophy. Nevertheless, vigorous spontaneous effort can cause both lung injury and diaphragm injury (myotrauma). These injuries lead to prolonged ventilation, difficult weaning, and increased morbidity and mortality. Normal expiration is passive due to the recoil of the lungs and chest wall. In mechanical ventilation, during expiration the ventilator controls the pressure (ie, the target value is PEEP), therefore, we must look at the flow and volume waveforms to see the physiology and patient-ventilator interactions. In expiration the patient-ventilation interaction is not characterized by timing but by work. Expiratory effort (ie, negative Pmus) will deform the flow waveform in a negative direction (away from baseline). Keywords: synchronization, spontaneous effort, lung injury, myotrauma, expiratory effort

A framework for synthetic power system dynamics.

We present a modular framework for generating synthetic power grids that consider the heterogeneity of real power grid dynamics but remain simple and tractable. This enables the generation of large sets of synthetic grids for a wide range of applications. For the first time, our synthetic model also includes the major drivers of fluctuations on short-time scales and a set of validators that ensure the resulting system dynamics are plausible. The synthetic grids generated are robust and show good synchronization under all evaluated scenarios, as should be expected for realistic power grids. A software package that includes an efficient Julia implementation of the framework is released as a companion to the paper.