Polite feedback signals in same-gender conversation-An investigation into the theory of politeness impact on the male speakers and female speakers use feedback signals in the same-gender conversation

交流是每天日常生活中分享知识和经验所必不可少的一部分。对话作为交流手段的一种主要形式,是一种即时即地发生的社会活动。反馈语是交互子系统中的(即对话过程中的)一种特定用语,主要表现为使用特定或固定的语言学词汇来引出上下文或是帮助理解或是暗示说话人态度等等。男性和女性参与者在会话过程中使用不同的策略或是选择合适的反馈语表达他们的意见,想法,目的,态度等等进而展现他们的礼貌。

超导磁储能装置提高柔性直流配电系统稳定性的研究

柔性直流配电系统中定功率控制的换流器具有恒功率负载特性,会降低系统阻尼,对系统的稳定性产生不利影响。针对该问题,在直流配电系统中加入超导磁储能SMES(superconducting magnetic energy storage)装置来提高系统的稳定性。推导了柔性直流配电系统的反馈控制模型,采用频域分析法研究了换流器恒功率负载特性对系统稳定性的影响,并结合数学模型和频域分析,指出SMES装置能够为电网提供正阻尼,增大了系统开环传递函数在剪切频率处的相位裕度,从而改善了系统稳定性。为防止超导磁体两端电压过高,SMES装置与直流配电网连接的DC/DC换流器需具备一定的电压调节性能,因此研究了采用模块化多电平DC/DC换流器DC-MMC(modular multilevel DC/DC converter)的SMES装置,通过调节子模块个数灵活设置换流器电压变比,在实现换流器能量双向流动的同时控制超导磁体两端电压,以保护储能装置。最后通过时域仿真波形验证了采用DC-MMC的SMES装置在提高柔性直流配电系统稳定性方面的可行性和有效性。

基于反馈机制的光子微波信号级联滤波方法

光子微波通信过程中,受噪声影响造成带宽变窄,降低了通信效率。为了优化光子微波通信质量,提出基于反馈机制的光子微波信号级联滤波方法。利用形态学腐蚀和膨胀去除信号模糊程度后,将相似度较高的信号聚集为连续区域,完成微波信号去噪。选用卡尔曼滤波器对微波信号测量噪声初次滤波,使用均值滤波以及双门限输出方案二次滤波双路光电反馈下生成的微波信号。通过两种滤波器的级联处理,去除微波信号中不同的杂波,实现窄线宽光子微波信号级联滤波。实验结果表明,所提方法级联滤波波动幅度小,能够平稳输出滤波结果,且不同温度下的级联滤波衰减特性相对平稳。

基于判决反馈的VDES解调系统设计与FPGA实现

甚高频数据交换系统(Very high frequency Data Exchange System,VDES)作为新一代船舶通信系统,具有广阔的应用前景。由于卫星相对船舶的高速运动,VDES中上行应用特定消息(Application-specific Message,ASM)链路会产生较大的多普勒频移,在接收端仅依靠已知训练序列估计的频偏等信道参数无法满足正确解调的性能要求。为此提出一种基于判决反馈的解调方法,通过分段解调,缩短每次解调的数据长度,提高解调时对频偏的容忍度,并利用每段解调的结果作为下一段未解调数据的导频,估计出当前数据中的信道参数。仿真结果表明,所提算法相较于无反馈相干解调算法性能大大提升。在上述研究的基础上,在可编程逻辑器件上实现了对ASM无导频上行链路的正确解调。

同步性质控在海洋地震采集中的重要应用

地震采集中震源和仪器记录的同步性质控对地震资料采集质量至关重要。实际地震采集过程中,由于设备的迭代发展,震源与仪器记录的同步性方面有了较高发展,反而在质控过程中容易忽略。一旦发生非人为设置造成的同步误差,会直接影响到采集资料的质量。而且同步误差通常难以准确测量,造成后期数据处理中无法予以精准消除相应误差。本文主要结合中海油服所使用的设备以及在实际施工过程中出现的问题,探讨触发信号异常和GPS授时系统出现异常造成的同步误差发生原因及相应的解决方案。

基于能量回馈的充电器老化测试系统

为解决传统的充电器测试方法测试效率低、自动化程度差以及长时间老化测试过程中存在大量直流能量的浪费等问题,设计了一种具备能量回馈功能的充电器老化测试系统。测试系统包括老化测试部分、能量回馈部分和信号采集部分,以STM32单片机芯片为核心控制单元,通过信号采集模块采集测试系统中的交流信号与直流信号并传输至单片机的ADC端口,与系统初始设定值进行对比,判断待测充电器是否合格;同时将充电器直流输出串联接入能量回馈单元,控制开关切换单元,然后将输出的220 V逆变电源连接到部分充电器的输入端口,并将充电器的直流能量逆变回馈至充电器的老化测试过程继续利用,采集能量回馈单元输出端交流可调负载上面的电流值,当交流可调负载上的电流值最小时,接入到能量回馈单元的充电器数量达到最大,能量回馈效率达到了60%以上,实现了节能、高效的充电器老化测试。

JOY连采机和梭车电气元件测试台的研制

为解决进口JOY连采机和梭车的电气元件在组装前不能进行测试,进而影响整机电控系统组装后的系统运行稳定性和可靠性,导致设备及电控系统维修返工率高的问题。神东煤炭集团设备维修中心重新设计、制造电气元件测试台(包含电气系统设计、显示模式、负载及信号反馈模式、测试台搭建)搭建连采机和梭车的电气通讯及控制回路以用于元件的单一或联合测试。经实测数据验证,当使用该测试台对维修元器件进行单一或联合测试后,元器件故障检出率可达100%,设备返工率降低至2.4%,预计每年可节约77万元维修、配件及人工费用。整体而言,测试台安全可靠,经济效益良好。

提高储能VSG并网有功响应性能的暂态阻尼策略

储能虚拟同步发电机(VSG)的并网有功在有功指令与电网频率2种扰动下存在动态超调与稳态偏差。提出有功微分反馈补偿(ADFBC)和有功微分前馈补偿(ADFFC)2种暂态阻尼策略,并在分别建立典型VSG、ADFBC和ADFFC 3种策略并网有功闭环小信号模型的基础上,给出了相应的参数设计方法。仿真和实验对比结果均验证了所提ADFBC和ADFFC暂态阻尼策略可有效提高储能VSG并网有功响应,在2种扰动下其并网有功既无动态超调又无稳态偏差。

“光电探测与信号处理”课程实践教学设计——以LED封装为例

LED封装作为“光电探测与信号处理”课程中一个重要的实践内容,通过对其教学内容、教学环节、教学反哺和教学评价环节进行设计,优化了教学内容,更新了教学理念,丰富了教学环节,增强了教学效果,提升了课堂效率。这一实践教学设计的执行实现了理论与生产实践的深度融合,加深了学生对理论知识的认知,有效地提升了学生的学习积极性,培养了严谨的作风和科学的态度,为以后毕业设计打下一定的基础。

Influence of Design Reference on Tracking Performance of Feedback Control

In this paper, we present an investigation on the tracking performances of feedback control as a function of reference signals. We use multi-objective optimal designs of feedback controls as a fair basis for comparing different control designs, and examine step, ramp, and periodic signals at various frequencies. Through comparing the tracking performances of controls designed with different reference signals,we find that the controls designed with ramp signals perform better in tracking step and ramp references than those designed with step signals. To track periodic signals, we find that the controls designed with periodic signals at the same frequency generally provide the best performance, and those designed with step and ramp signals perform comparably.

Synergistic inhibition of MEK and reciprocal feedback networks for targeted intervention in malignancy

The RAS-RAF-MEK-ERK signaling pathway(MAPK signaling pathway) plays a significant role in multiple pathological behaviors and is most frequently dysregulated in more than 30% of human cancers.As key elements in this pathway, MEK1/2 play crucial roles in tumorigenesis and the inhibition of apoptosis, which makes their inhibition an attractive antitumor strategy.Dozens of potent non-ATP-competitive allosteric MEK1/2 inhibitors have been developed that have produced substantial improvement in clinical outcomes over the past decade.However, the efficacy of these agents is limited, and response rates are variable in a wide range of tumors that harbor RAS and RAF mutations due to the development of resistance, which is derived mainly from the persistence of MAPK signaling and increased activation of the mutual feedback networks.Both intrinsic and acquired resistance to MEK inhibitors necessitates the synergistic targeting of both pathways to restore the therapeutic effects of a single agent.In this review, the significant role of the MAPK pathway in carcinogenesis and its therapeutic potential are comprehensively examined with a focus on MEK inhibitors.Then, the activation of feedback networks accompanying MEK inhibition is briefly reviewed.Combination strategies that involve the simultaneous inhibition of the original and resistance pathways are highlighted and elaborately described on the basis of the latest research progress.Finally, the obstacles to the development of MEK-related combination systems are discussed in order to lay the groundwork for their clinical application as frontline treatments for individual patients with MAPK-hyperactivated malignancies.

Stochastic resonance in a time-delayed asymmetric bistable system with mixed periodic signal

This paper studies the phenomenon of stochastic resonance in an asymmetric bistable system with time-delayed feedback and mixed periodic signal by using the theory of signal-to-noise ratio in the adiabatic limit. A general approximate Fokker-Planck equation and the expression of the signal-to-noise ratio are derived through the small time delay approximation at both fundamental harmonics and mixed harmonics. The effects of the additive noise intensity Q, multiplicative noise intensity D, static asymmetry r and delay time T on the signal-to-noise ratio are discussed. It is found that the higher mixed harmonics and the static asymmetry r can restrain stochastic resonance, and the delay time τ can enhance stochastic resonance. Moreover, the longer the delay time τ is, the larger the additive noise intensity Q and the multiplicative noise intensity D are, when the stochastic resonance appears.

A Grounded Capacitor Differentiator Using Current Feedback Amplifier

A new non-inverting RC active differentiator network base on a current feedback amplifier and using a grounded capacitor is described. Small time constant can be achieved by adjusting a single grounded resistor. Because the output impedance of the CFA is very low, the output terminal of the proposed circuit can be directly connected to the next stage. Experimental results that confirm theoretical analysis are presented.

基于不对称正负反馈效应的PQ功率控制并网逆变器稳定性分析

针对弱电网下PQ功率控制并网逆变器的稳定性问题,该文通过构建有功/无功环的小信号控制框图,首次揭示弱电网下PQ功率控制是一种不对称控制的本质,即无功环控制器会在有功和无功控制环中形成不对称的正负反馈环路。同时,基于PQ功率环小信号控制框图的不对称现象,揭示有功/无功环控制器参数变化对并网逆变器稳定性影响存在差异性的机理,指出无功环控制器参数变化对并网系统稳定性的影响程度要明显强于有功环控制器参数变化。在此基础上,借助有功与无功环小信号控制框图中的正负反馈效应,分析并网逆变器稳定性随无功环控制器参数增加而出现先增强后减弱的“拐点”现象。最后,通过仿真与实验验证了该文理论分析的正确性。

Vector tracking loops in GNSS receivers for dynamic weak signals

Vehicle positioning with the global navigation satellite system （GNSS） in urban environments faces two problems which are attenuation and dynamic. For traditional GNSS receivers hardly able to track dynamic weak signals, the coupling between all visible satellite signals is ignored in the absence of navigation state feedback, and thermal noise error and dynamic stress threshold are contradictory due to non-coherent discriminators. The vector delay/frequency locked loop （VDFLL） with navigation state feedback and the joint vector tracking loop （JVTL） with coherent discriminator which is a synchronization parameter tracking loop based on maximum likelihood estimation （MLE） are proposed to improve the tracking sensitivity of GNSS receiver in dynamic weak signal environments. A joint vector position tracking loop （JVPTL） directly tracking user position and velocity is proposed to further improve tracking sensitivity. The coherent navigation parameter discriminator of JVPTL, being able to ease the contradiction between thermal noise error and dynamic stress threshold, is based on MLE according to the navigation parameter based linear model of received baseband signals. Simulation results show that JVPTL, which combines the advantages of both VDFLL and JVTL, performs better than both VDFLL and JVTL in dynamic weak signal environments.

Analysis of Electronic Circuits with the Signal Flow Graph Method

In this work a method called “signal flow graph (SFG)” is presented. A signal-flow graph describes a system by its signal flow by directed and weighted graph;the signals are applied to nodes and functions on edges. The edges of the signal flow graph are small processing units, through which the incoming signals are processed in a certain form. In this case, the result is sent to the outgoing node. The SFG allows a good visual inspection into complex feedback problems. Furthermore such a presentation allows for a clear and unambiguous description of a generating system, for example, a netview. A Signal Flow Graph (SFG) allows a fast and practical network analysis based on a clear data presentation in graphic format of the mathematical linear equations of the circuit. During creation of a SFG the Direct Current-Case (DC-Case) was observed since the correct current and voltage directions was drawn from zero frequency. In addition, the mathematical axioms, which are based on field algebra, are declared. In this work we show you in addition: How we check our SFG whether it is a consistent system or not. A signal flow graph can be verified by generating the identity of the signal flow graph itself, illustrated by the inverse signal flow graph (SFG−1). Two signal flow graphs are always generated from one circuit, so that the signal flow diagram already presented in previous sections corresponds to only half of the solution. The other half of the solution is the so-called identity, which represents the (SFG−1). If these two graphs are superposed with one another, so called 1-edges are created at the node points. In Boolean algebra, these 1-edges are given the value 1, whereas this value can be identified with a zero in the field algebra.

基于复数滤波器的三相锁相环技术改进策略

提出了一种改进型前置复数滤波器PLL(Complex Coefficient Filter PLL,CCF-PLL),以增强锁相环在非理想电网条件下的估计性能。此方案在传统的CCF-PLL基础上,提出利用二阶广义积分器(Second-Order Generalized Integrator,SOGI)滤波以及改变复数滤波器的反馈信号的方案,来增强其在非理想电网条件的估计性能。对传统CCF-PLL和改进型CCF-PLL的性能进行仿真测试,测试结果验证了所提方案的有效性。

运用改进磷虾群算法的自抗扰控制方法

为了提升自抗扰控制效果,提出了基于改进磷虾群算法的自抗扰控制方法.利用线性自抗扰控制技术,设计电力系统自抗扰控制器;利用扩张状态观测器估计系统总扰动,在系统控制量内加入前馈微分信号,通过该控制器的线性误差反馈律自抗扰控制电力系统,采用改进磷虾群算法优化该控制器的反馈比例增益与反馈微分增益,提升自抗扰控制效果.实验结果表明,在不同扰动时,应用本文方法自抗扰控制后,可有效降低电力系统稳态误差有效值与谐波畸变率.

考虑损耗的永磁风力发电系统改进功率反馈法最大风能跟踪控制

永磁直驱风力发电系统(PMSG)采用传统功率反馈最大功率跟踪(MPPT)控制方法时,需要提前获取机组的功率-转速曲线,且机组的风能转换率会随着风机使用时间而变化,从而降低了功率反馈法的控制精度。本文基于传统功率反馈控制方法,在考虑发电机内部损耗的前提下,提出考虑损耗的永磁直驱风电系统改进功率反馈法MPPT控制策略。该策略通过爬山搜索法跟踪风机最大功率点,在考虑损耗的基础上准确地计算出功率反馈法所需要的比例系数,进而计算出参考功率,从而实现最大风能跟踪。通过对该策略进行仿真和实验研究,验证了控制策略的有效性和可行性。