Implementation of an energy-efficient scheduling scheme based on pipeline flux leak monitoring networks

Flow against pipeline leakage and the pipe network sudden burst pipe to pipeline leakage flow for the application objects,an energy-efficient real-time scheduling scheme is designed extensively used in pipeline leak monitoring. The proposed scheme can adaptively adjust the network rate in real-time and reduce the cell loss rate,so that it can efficiently avoid the traffic congestion. The recent evolution of wireless sensor networks has yielded a demand to improve energy-efficient scheduling algorithms and e...     

地震卓越频率(EDF)对主动调谐质量阻尼器抗震控制设计的影响评价

基于Kanai-Tajimi地震动模型，建立了设置主动调谐质量阻尼器(ATMD)结构的传递函数。于是，ATMD最优参数的评价准则定义为：设置ATMD结构的最大动力放大系数的最小值的最小化。ATMD有效性的评价准则定义为：设置ATMD结构的最大动力放大系数的最小值的最小化与未设置ATMD结构的最大动力放大系数之比。ATMD冲程的评价准则定义为：ATMD的最大动力放大系数。基于选择的评价准则，研究了地震卓越频率(EDF)对ATMD在控制结构位移响应时的最优参数、有效性和冲程的影响。     

基于自反馈光注入结构的双波长可调谐掺Er3+光纤激光器

为了实现可调谐双波长激光输出,提出并设计了一种基于自反馈光注入结构的掺Er3+光纤(EDF)激光器,并对激光器的基本原理及实现方案进行了理论分析和实验验证。系统结构设计采用976nm波长的LD作为泵浦源,结合EDF,两支光纤布拉格光栅(FBG)和光纤环形镜(FLM)产生激光,并通过在FLM中熔接饱和吸收体(SA)起到稳频作用;将FLM输出激光耦合进入谐振腔形成自注入结构,与腔内振荡激光形成干涉,抑制模式跳变;通过控制两支FBG之间的可调谐衰减器调节谐振腔内的增益和损耗,实现单个波长或双波长输出。实验结果表明:SA长采用4m、EDF长采用6m时,激光输出阈值为28mW,将反馈光注入谐振腔后,系统阈值为25mW,输出激光波长随时间漂移得到明显抑制;当泵浦光功率为80mW时,通过调节位于两支FBG之间的可调谐衰减器(VA)获得稳定的双波长激光输出;随着泵浦功率增加,激光输出功率具有良好的线性度和稳定性。在1 540nm波长处激光输出最大功率为1.16mW,信噪比(SNR)大于50dB;在1 545nm波长处激光输出最大功率为1.89mW,SNR大于50dB。     

掺铒光纤放大器特性分析及长度优化设计

掺饵光纤放大器（ＥＤＦＡ）是光纤通信系统中的关键器件之一。文中从ＥＤＦＡ的基本理论出发，对ＥＤＦＡ的各种特性进行了计算机模拟分析，并研究了ＥＤＦＡ的长度优化设计，实验结果与理论计算相吻合。     

石墨烯被动锁模谐波阶数可调的掺铒光纤孤子激光器

采用石墨烯被动锁模的掺Er光纤(EDF)环形腔,获得稳定的谐波阶数可调的孤子脉冲激光。通过调节EDF环形腔中的偏振控制器(PC)改变光腔损耗,实现了锁模谐波从一阶至四阶的可控运转。连续锁模基频重复频率为3.873MHz,中心波长为1 557.6nm,谱线宽度为4.5nm,有明显孤子边带,信噪比(SNR)约为45dB,二、三和四次谐波锁模脉冲重复频率分别为7.745、11.618和15.491MHz。本文的实验结果可用工作于反常色散区锁模激光器的多孤子形成机理来解释。     

Gain improvement in a dual-stage S-band EDFA by filtration of forward C-band ASE

Gain improvement in a dual-stage S-band erbium-doped fiber amplifier (S-band EDFA) is demonstrated using a broadband fiber Bragg grating (FBG) operating in the conventional-band (C-band) region or a C-band/S-band wavelength division multiplexing (WDM) coupler which filters out the forward C-band amplified spontaneous emission (ASE) in the amplifier system, thus increasing the population inversion in the S-band region. The gain for the amplifier with the WDM coupler increases by about 8.5 dB with an input signal power of ?40 dBm, compared to that of the conventional dual-stage amplifier. The gain improvement varies from 4.0–9.2 dB at a wavelength region between 1480 to 1512 nm without a significant noise figure penalty.     

Comparison of JSFR design with EDF requirements for future SFR

A comparison of the Japan sodium-cooled fast reactor (JSFR) design with the future French sodium-cooled fast reactor (SFR) concept has been done based on the requirements of Electricité de France (EDF), the investor-operator of the future French SFR, and the French safety baseline, under the framework of an EDF and Japan Atomic Energy Agency (JAEA) bilateral agreement of research and development cooperation in future SFRs..     

宽带、高稳定掺铒光纤超荧光光源

概述了掺铒光纤超荧光光源的基本原理、主要结构和特点;介绍超荧光光源的最新研究进展,报道我们研制的中心波长稳定的L波段超荧光宽带光源和单级掺铒光纤C L波段超荧光宽带光源。     

EDF调度方法在交换式工业以太网中的实现

针对工业以太网的数据特点 ,通过在以太网数据帧中引入IEEE80 2 .1Q优先级字段来区分周期性实时数据和非实时数据 ,并对前者优先进行传送。同时还在周期性数据帧中引入截止期限字段来区分其不同的紧急程度 ,并对其采用非中断的EDF调度方法来改善周期性数据帧的端到端延迟。最后通过仿真试验验证了该方法的可行性。     

Tests for Exponentiality When Origin and Scale Parameters Are Unknown

Several methods are examined for testing for the exponential distribution, using complete samples, when both the scale and location parameters are unknown. Percentage points are given for empirical distribution function (EDF) tests in which both parameters are estimated from the data, and power studies are reported to compare these tests with other goodness-offit techniques for the exponential distribution, particularly those based on regression methods. It is found that the EDF statistics W ² and A ² have overall good power properties, with A ² slightly superior.