Optimizing offset times in Optical Burst Switching networks with variable Burst Control Packets sojourn times

In this paper, we consider the case of an Optical Burst Switching (OBS) network where the Switch Control Units (SCU) do not work at the peak rate. As a consequence, some Burst Control Packets (BCPs) will have to wait in queue to be processed, and then the BCP sojourn time will be variable. On the contrary, the optical burst does not leave the optical domain and the delay suffered is close to the propagation delay. Hence, chances are that the BCP arrives late to a given switch and, in that case, the optical burst will be dropped. We propose a Load-adaptive Offset Time algorithm (LOT) that takes into account the BCP variable sojourn time for the offset time calculation. The algorithm performs on-line calculation of the Discrete Fourier Transform (DFT) of the BCPs waiting time pdf. Our findings show that this procedure is very efficient both in terms of bandwidth usage and processing load. For example, considering a Gaussian service time for the BCPs, it turns out than less than 45 coefficients are necessary to calculate the offset time for a SCU utilization factor larger than 0.1.     

基于Rough测度的弱信号空间极化特征快速拾取方法

开展非电磁波的微弱信号处理研究,对于实际环境下的信号监测与探测具有很强的现实意义和应用前景,也面临着许多挑战.本文以微弱气体信号的早期快速探测作为研究背景,在分析了微弱信号早期探测的不确定性的基础上,运用粗糙集的数学方法,提出了基于Rough测度的信号处理方法,以快速拾取弱信号空间的极化特征,并以一维中尺度空间的信号源方位探测为实例,给出了基于Rough测度的快速拾取弱信号空间极化特征的具体算法,通过该算法计算,可以从初始无序的采样信号空间中找到具有趋势性的信号空间极化特征,从而实现信号方位快速识别与跟踪,其仿真结果表明该方法具有良好的稳健性、准确性和容错性.     

极化可区分光子的双光子干涉

双光子干涉本质是整体状态不可区分.两光子可区分而整体态不可区分时,仍然能发生双光子干涉.将HOM型与Franson型双光子干涉相结合,提出一个可实现两光子可区分而整体态不可区分的双光子干涉实验方案.此双光子干涉实验方案中两光子极化方向相互垂直,但方案中并不擦除两光子的极化可区分信息.     

Nonlinear disturbance observers for robotic continuum manipulators

Robots are an indispensable part of modern production lines. Usually working in designated areas, they are separated from human workers in order to avoid collisions. A safe collaborative work environment is enabled by so-called soft robots, which constitute a human-friendly alternative to classical rigid industrial robots. However, modeling soft robots proves difficult and results in a lack of accuracy for control tasks. In this contribution, a disturbance observer-based control is proposed in order to improve tracking behavior. In doing so, unknown model errors are considered as disturbances and estimated by an observer. This estimate is used to actively reject the perturbation. Different disturbance observers are designed and implemented for a soft quasi-continuum manipulator, amongst them two nonlinear disturbance observers and two extended state observers. The distinction in the versions of the same observation concept lies in the disturbance dynamics assumption, which is either considered static or as a damped double integrator. All implemented concepts combined with a PD control show superior performance compared to an existing benchmark concept based on PID-like control. Thanks to the modularity of this approach, disturbance observers can be further investigated in combination with other control strategies.     

Polymer-Based Solid Electrolytes: Material Selection,Design, and Application

Polymer-based solid electrolytes (PSEs) have attracted tremendous interests for the next-generation lithium batteries in terms of high safety and energy density along with good flexibility. Remarkable performances have been demonstrated in PSEs, which endowed PSEs with the potential to replace liquid electrolytes to meet the market demands. In this review, polymer matrices, different polymer architectures, and functional filler materials used in PSEs are discussed to explore the design concepts, methodologies, working mechanisms, and pros and cons of various PSEs. In addition, their recent notable applications in all-solid-state lithium ion batteries, lithium–sulfur batteries, suppression of lithium dendrites, and flexible lithium batteries are also introduced. Finally, the challenges and future prospects are sketched to provide strategies to explore novel PSEs for high-performance all-solid-state lithium batteries.     

基于差分格式的SOR-MC 高效计算

随着研究的深入,仿真的计算量爆炸式地增加,提高计算效率显得尤为重要。分析了蒙特卡洛法（MC）与差分法的逐次迭代(SOR)的优缺点后,本文提出了一种新型的混合算法SOR-MC,利用蒙特卡洛法（MC）随机游动为逐次迭代(SOR)构造一个初始迭代值,提高求解速度。并利用变网格精度进一步改进SOR-MC算法。通过多个数值试验验证了混合算法及其改进能大大减少了迭代次数,有效地提高了计算效率。     

开放的ladder型无反转激光系统的稳定性分析

利用开放的ladder型无反转激光系统的密度矩阵运动方程组的定态解和激光场运动方程分析了系统的稳定性。结果表明：如果增益大于激光腔损耗，则零解是不稳定的；如果增益小于激光腔损耗，则零解是稳定的；如果增益大于激光腔损耗，则非零解是稳定的。     

邦加球在分析光纤偏振态传输中的应用

应用邦加球法对单模光纤及其一、二阶偏振模色散(PMD)和保偏光纤及其在非线性效应中偏振态的传输过程进行了分析。分析表明，邦加球在光纤偏振态传输的分析中具有独到之处。     

扭转椭圆双折射光纤环形腔输出特性

对扭转椭圆双折射光纤环形腔的带阻输出特性进行了分析和计算。结果表明，任意椭圆偏振态输入，光纤的双折射和扭转使光纤环形腔带阻输出特性中的谐振峰分裂为两组，对应于光纤的两个本征偏振态。谐振频率发生偏移，偏移量取决于光纤的双折射参数和扭转速率，两组谐振峰的相对幅度取决于光纤的双折射参数、扭转速率和输入偏振态。若输入偏振态为双折射光纤本征偏振态之一，就仅出现一组谐振峰。光纤的双折射和扭转对环形腔的精细度没有影响。     

Cl/Cl2/He+HN3/He反应体系的实验研究

本文对微波解离C12产生CI，与HN3／He的混合气体反应产生的激发态粒子NCI(a1△)和NCl(b1∑)进行了实验研究．对NCl(a1△)和NCl(b1∑)的荧光光谱进行了测量并对光谱强度沿气流方向的变化趋势以及依赖几种不同气体流量和配比的变化关系进行了研究．给出了NCl(a1△)和NCl(b1∑)产生的最佳实验参数及配比关系，并对结果做了讨论．