Brexit: Tracking and disentangling the sentiment towards leaving the EU

On 23 June, 2016, the UK held a referendum to decide whether to stay in the European Union or leave. The uncertainty surrounding the outcome of this referendum had major consequences for public policy, investment decisions, and currency markets. We discuss some of the subtleties involved in smoothing and disentangling poll data in light of the problem of tracking the dynamics of the intention to Brexit, and propose a multivariate singular spectrum analysis method that produces trendlines on the unit simplex. The trendline yield via multivariate singular spectrum analysis is shown to resemble that of local polynomial smoothing, and singular spectrum analysis presents the nice feature of disentangling the dynamics directly into components that can be interpreted as changes in public opinion or sampling error. The merits and disadvantages of some different approaches for obtaining smooth trendlines on the unit simplex are contrasted, in terms of both local polynomial smoothing and multivariate singular spectrum analysis.     

基于多维频谱地图的干扰规避

针对复杂电磁环境下卫星移动通信系统可靠通信需求，利用频谱地图多维数据呈现优势，提出了基于多维频谱地图的干扰规避方法。通过建立卫星移动通信系统波束、时隙、子频带、干扰强度等多维信息关联的频谱地图，利用数据挖掘方法对频谱可用情况进行预测，基于预测结果及用户QoS(Quality of Service)需求生成干扰规避策略，通过星地联合频谱资源调配实现系统干扰规避。该方法为卫星移动通信系统干扰规避提供了一种全新的思路，可提升卫星移动通信系统干扰防护能力。     

强耦合氢等离子体中Be~（3＋）的结构和辐射性质研究

采用离子球模型研究了强耦合氢等离子体中杂质Be3＋的原子结构和光谱性质随离子球大小的变化规律.结果表明,强耦合等离子体的屏蔽效应对其中的原子结构和光谱影响很大,而且不同模型给出的结果有很大的差别;在离子球模型下,类氢的轨道电离能随着屏蔽效应的增强而单调减小,轨道的简并度解除,但是随着屏蔽效应的增强,轨道将二次简并,轨道能级关于角动量发生发转;不同主量子数n两能级之间辐射的光谱随着屏蔽效应的增强先红移而后蓝移,在非相对论情况下,屏蔽效应引起同n轨道能级劈裂,辐射出新的光谱,该光谱随着等离子体效应的增强先蓝移后红移,经过再次简并后继续蓝移,直到不再辐射出光谱为止;轨道之间的重叠积分由于等离子体屏蔽效应先减小而后增大,从而振子强度随着等离子体屏蔽效应的增强先减小而后增大.目前的计算数据与可查的数据非常符合.     

A neuro-fuzzy combination model based on singular spectrum analysis for air transport demand forecasting

Air transport demand forecasting is receiving increasing attention, especially because of intrinsic difficulties and practical applications. Total passengers are used as a proxy for air transport demand. However, the air passenger time series usually has a complex behavior due to their irregularity, high volatility and seasonality. This paper proposes a new hybrid approach, combining singular spectrum analysis (SSA), adaptive-network-based fuzzy inference system (ANFIS) and improved particle swarm optimization (IPSO), for short-term air passenger traffic prediction. The SSA is used for identifying and extracting the trend and seasonality of air transport demand and the artificial intelligence technologies, including ANFIS and IPSO, are utilized to deal with the irregularity and volatility of the demand. The HK air passenger data are collected to establish and validate the forecasting model. Empirical results clearly points to the enormous potential that the proposed approach possesses in air transport demand forecasting and can be considered as a viable alternative.     

一种基于差分相干积累的扩频信号开环同步捕获方法

将全数字接收机的结构引入到扩频接收机中,用一种前向的并行处理结构来代替传统码延迟锁定环的反馈结构,采用差分相干积累的方法捕获低信噪比扩频信号的伪码相位.仿真结果表明,这种方法能快速可靠地捕获低信噪比扩频信号的码同步,可以应用于开环的全数字扩频接收机中.     

小波域抑制多音干扰的扩频接收机

利用小波包理论提出了一种快速、准确地识别并且抑制多音干扰的有效方法。该方法利用小波包理论将多音干扰的各条谱线逐个定位，然后通过功率谱分析的方法来识别多音干扰的存在区间，最后将被干扰污染的区间逐个切除并反向重构接收到的信号。实验证明该方法的误比特率性能在强干扰时要优于以前的FFT域切割法。     

两种自适应杂波抑制技术的比较：AMTI及ADPCA技术性能的分析和比较

本文在讨论机载雷达地面杂波回波的基础上，分析了ＡＭＴＩ和ＡＤＰＣＡ系统的性能。对这两个系统从原理上，并利用计算机模拟结果及实验结果进行了比较。本文将有助于工程实现。     

一种新的卫星通信信号快速盲检测方法

提出了一种卫星通信信号快速盲检测算法,该算法能够适应频谱不重叠的多信号环 境,并能准确估计信号的数量、中心频率及带宽等参数。算法既高效又简单,所需数据量少 且适应低信噪比条件,适于在星载设备上实现。理论分析和仿真及测试结果证明了算法的有 效 性。     

一种基于遗传算法的战场频率分配方法

分析了遗传算法的原理及其在频率分配领域中的应用,提出了一种启发式战场频率 分配方法。该方法通过改进传统遗传算法的选择、交叉、变异过程来实现频率分配的特殊 用途,并借助代价函数对生成的频率分配方案进行质量评估。仿真结果表明,该方法能够在 一 定程度上提高频谱资源的使用效率,可为从事频谱管理等相关行业的技术人员提供参考。     

某类高阶偏微分系统离散谱的估计

考虑某类高阶偏微分系统离散谱的估计,利用谱理论、矩阵运算、分部积分、测试函数、Ray—leigh定理和不等式估计等方法,获得了用前n个谱来估计第n＋1个谱的上界的不等式,且其估计系数与区域的几何度量无关,其结论是文献[4—5]的进一步推广．