Effects of information transmission delay and channel blocking on synchronization in scale-free Hodgkin-Huxley neuronal networks

In this paper,we investigate the evolution of spatiotemporal patterns and synchronization transitions in dependence on the information transmission delay and ion channel blocking in scale-free neuronal networks.As the underlying model of neuronal dynamics,we use the Hodgkin-Huxley equations incorporating channel blocking and intrinsic noise.It is shown that delays play a significant yet subtle role in shaping the dynamics of neuronal networks.In particular,regions of irregular and regular propagating excitatory fronts related to the synchronization transitions appear intermittently as the delay increases.Moreover,the fraction of working sodium and potassium ion channels can also have a significant impact on the spatiotemporal dynamics of neuronal networks.As the fraction of blocked sodium channels increases,the frequency of excitatory events decreases,which in turn manifests as an increase in the neuronal synchrony that,however,is dysfunctional due to the virtual absence of large-amplitude excitations.Expectedly,we also show that larger coupling strengths improve synchronization irrespective of the information transmission delay and channel blocking.The presented results are also robust against the variation of the network size,thus providing insights that could facilitate understanding of the joint impact of ion channel blocking and information transmission delay on the spatiotemporal dynamics of neuronal networks.

Novel Adaptive Neural Controller Design Based on HVDC Transmission System to Damp Low Frequency Oscillations and Sub Synchronous Resonance

This paper presents the effect of the high voltage direct current (HVDC) transmission system based on voltage source converter (VSC) on the sub synchronous resonance (SSR) and low frequency oscillations (LFO) in power system. Also, a novel adaptive neural controller based on neural identifier is proposed for the HVDC which is capable of damping out LFO and sub synchronous oscillations (SSO). For comparison purposes, results of system based damping neural controller are compared with a lead-lag controller based on quantum particle swarm optimization (QPSO). It is shown that implementing adaptive damping controller not only improves the stability of power system but also can overcome drawbacks of conventional compensators with fixed parameters. In order to determine the most effective input of HVDC system to apply supplementary controller signal, analysis based on singular value decomposition is performed. To evaluate the performance of the proposed controller, transient simulations of detailed nonlinear system are considered.

A consensus time synchronization protocol in wireless sensor network

Time synchronization is one of the base techniques in wireless sensor networks(WSNs).This paper proposes a novel time synchronization protocol which is a robust consensusbased algorithm in the existence of transmission delay and packet loss.It compensates for transmission delay and packet loss firstly,and then,estimates clock skew and clock offset in two steps.Simulation and experiment results show that the proposed protocol can keep synchronization error below 2μs in the grid network of 10 nodes or the random network of 90 nodes.Moreover,the synchronization accuracy in the proposed protocol can keep constant when the WSN works up to a month.

Taming desynchronized bursting with delays in the Macaque cortical network

Inhibitory coupled bursting Hindmarsh-Rose neurons are considered as constitutive units of the Macaque corti- cal network. In the absence of information transmission delay the bursting activity is desynchronized, giving rise to spatiotemporally disordered dynamics. This paper shows that the introduction of finite delays can lead to the synchro- nization of bursting and thus to the emergence of coherent propagating fronts of excitation in the space-time domain. Moreover, it shows that the type of synchronous bursting is uniquely determined by the delay length, with the transi- tions from one type to the other occurring in a step-like manner depending on the delay. Interestingly, as the delay is tuned close to the transition points, the synchronization deteriorates, which implies the coexistence of different bursting attractors. These phenomena can be observed by different but fixed coupling strengths, thus indicating a new role for information transmission delays in realistic neuronal networks.

Design of Wireless Transmission System for Shallow Seismograph Based on 433 M Module

Because of its portability,the non-cable seismograph has become the future development trend of geophysical instruments.A new wireless data transmission device of 433 M module was proposed;a wireless network was built using the EL1663B_PA module of the SI4463 core,and through the SPI interface to modify the internal parameters.Data transmission used dual antenna mode,the main station as the center of the wireless network coverage up to 550 m or more.The wireless time synchronization system was designed to realize the wireless connection communication between the shallow seismograph and the sensor of each observation point.This program aimed to eliminate the necessary connecting cable and batteries between the conventional shallow seismograph and the detector,greatly reducing the weight of the equipment,and making the shallow seismograph truly low cost,lightweight,flexible and easy to operate and so on.

基于故障时刻自同步的波形比较式多端配电网快速保护方案

为打破电气量的同步采集技术壁垒,并合理应对不平衡差流问题,分析了基于故障检测时刻保护数据自同步的实现方法,利用多端电流合成和Tanimoto系数构建了波形相似度比较式保护新判据。基于5G网络数据实时传输功能,形成了一套适用于多端配电网的综合快速保护方案。经PSCAD/EMTDC软件仿真,验证了所提方案能够快速可靠地确定故障区段,能很好地适应配电网复杂故障场景。

基于UWB技术的矿井低功耗无线传感器网络研究

针对煤矿井下各类参数有线监测系统的布线复杂、维护困难、扩展性差等问题,基于UWB技术研究了矿井低功耗无线传感器网络,采用STM32L151微处理器和DW1000芯片设计了具有自动组网、数据多跳传输和测量距离等功能的传感器节点。详细介绍了矿井低功耗无线传感器网络的组网机制、传感器数据多跳传输技术和低功耗休眠算法等关键技术。试验结果表明,传感器节点入网时间与网络深度成正比,网络深度每增加1级,入网时间就增加1个数据传输周期;传感器数据传输时延不超过1 s,通信距离可达100 m,未入网时的平均工作电流为230μA,已入网时的平均工作电流为680μA。该无线传感器网络为煤矿安全监测系统提供了一种低功耗、低成本且高可靠性的数据传输通道和平台。

调频同步广播网设计原则及建设方案

探讨调频(Frequency Modulated,FM)同步广播网在大连市广播电台应用的设计原则、系统构成及工作原理,并提出相关的建设方案。介绍调频同步广播网技术在大连市广播电台的具体应用,为相关领域提供参考。

电力通信SDH光纤传输网建设及应用

同步数字体系(Synchronous Digital Hierarchy,SDH)光纤传输网在电力通信中扮演着至关重要的角色。光纤传输网凭借其高带宽、大容量以及高可靠性的特性,已成为电力通信的骨干网络技术。该技术支持电力系统的远程控制、实时监测以及灾难恢复等关键功能,显著提高了电力系统的运行效率和服务质量。通过分析SDH技术的基本概念、建设流程及其在电力通信中的应用,揭示SDH光纤传输网对于电力系统稳定运行的重要贡献,并对其未来发展趋势进行展望。

SDH传输网络时钟倒换分析及配置优化方案

针对广州局厦深线SDH传输网络时钟倒换过程中出现的时钟环路问题,通过研究SDH网元的组网架构,确认在时钟倒换过程中,各网元SDH的时钟来源发生了变化;分析SDH的常见时钟源种类,确认SDH时钟根据同步状态信息来区分时钟同步质量等级;分析SDH时钟倒换流程,明确广州局SDH同步时钟组网配置的原则,由此提出SDH时钟配置的优化方案;结合厦深线SDH网元的组网架构,优化SDH网元主备定时链路时钟配置。调整后进行复测,该方案极大程度降低了SDH网元发生时钟环路的风险,对铁路通信设备维护具有参考意义。

电力调度通信网络SDH传输架构优化设计研究

在电力调度的高峰时段,实时数据网络通信需求激增,同步数字体系(Synchronous Digital Hierarchy,SDH)架构带宽利用率低,出现传输瓶颈,无法满足网络传输的需求,影响电力调度实时性。因此,文章提出设计电力调度通信网络SDH传输架构。通过优化后的电力调度通信网络设备,调整通信网络SDH拓扑结构,确定合适的节点位置,优化通信网络SDH传输通路组织。同时,加强网络电力调度通信安全防护。根据仿真测试结果,文章方法的信息传输平均速率为1.94 Mb/s,数据同步完成时间为8 s,证明通过优化设计,可以提高电力调度通信网络SDH传输架构的传输效率和电力系统的稳定性。

通信信息工程传输与接入网技术探讨

进入网络时代后,信息网络连通千家万户,提高了人们沟通效率和质量,也对通信传输技术提出更高的要求。基于此,文章对通信信息工程传输技术进行分析,同时研究了通信信息工程接入网技术,以期助推传输技术和接入网技术的发展,保证通信质量,提升通信工程的综合效益。

Synchronization transition of a modular neural network containing subnetworks of different scales

Time delay and coupling strength are important factors that affect the synchronization of neural networks.In this study,a modular neural network containing subnetworks of different scales was constructed using the Hodgkin–Huxley(HH)neural model;i.e.,a small-scale random network was unidirectionally connected to a large-scale small-world network through chemical synapses.Time delays were found to induce multiple synchronization transitions in the network.An increase in coupling strength also promoted synchronization of the network when the time delay was an integer multiple of the firing period of a single neuron.Considering that time delays at different locations in a modular network may have different effects,we explored the influence of time delays within each subnetwork and between two subnetworks on the synchronization of modular networks.We found that when the subnetworks were well synchronized internally,an increase in the time delay within both subnetworks induced multiple synchronization transitions of their own.In addition,the synchronization state of the small-scale network affected the synchronization of the large-scale network.It was surprising to find that an increase in the time delay between the two subnetworks caused the synchronization factor of the modular network to vary periodically,but it had essentially no effect on the synchronization within the receiving subnetwork.By analyzing the phase difference between the two subnetworks,we found that the mechanism of the periodic variation of the synchronization factor of the modular network was the periodic variation of the phase difference.Finally,the generality of the results was demonstrated by investigating modular networks at different scales.

一种水下接收端同步的并发媒体接入控制协议

针对水下声信号的低传播速度导致的时空不确定性问题,能够高效的利用水下声信道的长传播时延的信道预约技术,常被水下传感器网络的媒体接入控制协议的设计所采用,为了探索设计水下传感器网络的高性能媒体接入控制协议,以信道预约技术为基础,提出了一种新型的适用于移动水下传感器网络的,基于接收端同步的并发媒体接入控制协议,即CMACRS(concurrent medium access control based on receiver synchronization),新协议采用信道预约方法,实现了多个发送节点的并发传输。广泛的仿真结果显示,在吞吐量等性能方面,新协议优于非时隙级并发传输的水下媒体接入控制协议。

基于时间敏感网络的列车通信网络时间同步与流量整形技术研究

目前城市轨道交通列车多网融合通信系统无法保证关键性数据传输的确定性。分析了该系统对TSN(时间敏感网络)技术的需求,构建了流量整形网络试验平台,开展了基于TSN技术的时间同步与流量整形的相关测试。试验结果表明:在没有其他外界条件干扰的情况下,可以实现预期的列车通信网络时间同步功能;流量整形技术在网络带宽达到上限的极端情况下,仍可以保证关键性数据传输的确定性。

Time Synchronization for Transmission Substations Using GPS and IEEE 1588

Time synchronization systems that utilize the global navigation satellite systems(GNSS)are widely used in the monitoring,control,and protection of transmission networks.They ensure that phasor measurement units(PMUs)can accurately monitor voltage phase angles,increase the accuracy of fault locators,enhance the capabilities of disturbance recorders,and allow differential feeder protection to use re-routable communication networks.However,concern about the reliability of GNSS receivers used in intelligent electronic devices(IEDs)have been reported;problems include mal-operations of differential protection,erroneous satellite timing/location messages,inappropriate installations,and blocking of satellite signals due to illegal use of GNSS jammers in vehicles.Utilities now require a timing system less dependent on the use of low cost GNSS receivers integrated into IEDs,but one that uses Grandmaster clocks,slave and transparent clocks,and an Ethernet communication network.The IEEE 1588-2008 synchronization protocol uses the Ethernet to disseminate a global time reference around a substation.A future substation will probably include duplicate 1588 grandmasters,each incorporating stable oscillators with GNSS and terrestrial receivers,in conjunction with a 1588 compliant Ethernet data network with slave and transparent clocks,and redundancy boxes for interfacing with IEDs.Although IEEE 1588 protocol is promising for future substation automation systems,its performance and impact has to be fully evaluated before it can be used in real substations.This paper describes how an IEEE 1588 time synchronization testbed is designed,constructed,and tested.Testing involves measuring the time offset when the Ethernet is heavily loaded with other traffic and the holdover capability of 1588 clocks.Additional delay introduced by IEEE 1588 traffic is also measured.As there is limited testing on GPS receivers within the power industry,this paper also uses the testbed to evaluate the steady state and transient behavior of GPS receivers.The results show a 1588 time synchronization system is accurate,secure,and ideally suited for protection and control applications,compared to a timing system merely based on GPS receivers.The information described in this paper should increase a utility’s confidence in applying IEEE 1588 timing in a real substation.

基于网络数据同步的测绘数据压缩技术研究

传统测绘数据压缩技术数据压缩工作很难实现数据无损。为解决这一问题,提出基于网络数据同步的测绘数据压缩技术研究。利用网络数据同步技术实现压缩数据与压缩信号的同步,在此基础上,优化压缩工作的压缩率和压缩时间属性,实现测绘数据的压缩。实验结果表明:设计的基于网络数据同步的测绘数据压缩方法数据传输同步水平高,压缩后数据质量高,实现了不同网络下的无损压缩。

MQTT技术在公路收费系统中的应用展望

数据传输在公路收费系统中起到关键作用,随着技术进步呈现物联网整合、数据安全性提升、高性能网络等发展趋势。引入MQTT技术可以使实时数据传输、设备状态监控、高并发处理等方面得到改善。MQTT是一种轻量级、高效的通信协议,采用发布订阅模式,可以实现设备间的可靠异步消息传递。它具有实时性、灵活性、服务质量保证等优点。公路收费系统需要车辆流量监测、收费监控、设备状态监测等多方面实时数据传输。MQTT可用于公路收费系统中收费设备的状态监控和通信控制,以及业务数据流的多点同步监控。MQTT应用可以带来实时性、高效性、资源丰富性等多方面好处,它有望拓展公路收费系统的实时监控范围、简化系统间通信、推动收费设备网络化、实现多点同步监控等。

铁路通信传输系统的组网与优化技术

通过对铁路通信传输系统功能的描述,介绍了同步数字体系(Synchronous Digital Hierarchy,SDH)和光传送网(Optical Transport Network,OTN)的特点,以及在传输网中的应用和优化原则。结合铁路传输系统的三层网络结构,从保障业务的安全性方面,分别介绍了骨干层、汇聚层和接入层传输系统的网络组网、设置原则,探讨了网络优化技术,并介绍了传输系统使用的光纤光缆及电源的应用原则与优化内容。

传输技术在通信工程中的应用研究

随着经济的持续发展,通信工程领域取得巨大突破,各地区用户对信息传输的质量、效率提出更高的要求,传输技术的推广与应用也受到广泛关注。现阶段,通信工程中所应用的传输技术类型主要有同步数字体系(Synchronous Digital Hierarchy,SDH)、波分复用(Wavelength Division Multiplexing,WDM)以及自动交换光网络(Automatic Switched Optical Network,ASON)3种。传输技术在通信工程中的有效应用可以极大地提升信号传输的安全性和可靠性,从而发挥出自身的价值。针对传输技术在通信工程中的应用展开深入探讨,介绍了传输技术的类型、特点及具体应用,以供参考。