加权投票自适应的联络中心多类型任务量预测

联络中心排班需要准确预测到达任务量的各种类型。联络中心任务量数据庞大复杂,针对多类型任务的预测方法进行了研究,实现了对联络中心大量任务数据进行准确预测类型任务的目的。首先分析了任务量数据特点,确定了工作日和休息日对任务类型的影响。工作日使用PSO优化LIBSVM模型的参数,作为弱分类器用自适应增强算法迭代训练,提出用加权投票方法融合弱分类器的思想;休息日直接使用PSO-SVM模型预测。实验结果表明,该方法的分类准确率相对于传统方法准确率有很大提高。这对联络中心的人员排班管理具有重要的作用,对其他的服务行业的任务预测分类也有重要的参考价值。     

Adaptive Learning and Iterated Weak Dominance

This article addresses the idea that rational players should not play iteratively weakly dominated strategies by showing that when a particular type of adaptive learning process converges, then players must have learned to play strategy profiles equivalent to those that survive iterated nice weak dominance and, for certain games, equivalent to those that survive iterated weak dominance. For games satisfying the weak single crossing condition, the set of strategies that survive iterated weak dominance is small in that its bounds are pure strategy Nash equilibria. The results hold regardless of the order in which dominated strategies are eliminated.Journal of Economic LiteratureClassification Number: C72.     

基于双通道接收的干扰对消性能分析

为了探究在工程实现中卫星通信地球站使用干扰对消抵抗来自空中平台或周边干扰的可行性,对不同接收环境下的干扰对消性能进行了分析。首先,在假定2个通道中干扰差异被准确估计并补偿的情况下,推导出理论性能的近似计算公式;然后,采用最小均方(least mean square, LMS)自适应滤波器对2个通道干扰的差异进行补偿,完成干扰对消;最后,通过仿真实验对使用LMS自适应滤波器的干扰对消进行验证。结果表明：干扰对消的理论性能在卫星信号与干扰入射夹角大于15°时信噪比恶化可以接近0 dB,而夹角小于15°时信噪比恶化程度明显提高;除了入射夹角的影响外,采用LMS自适应滤波器的干扰对消性能还受算法参数、干扰大小等其他因素的影响,对于固定频点的干扰,在入射夹角大于4°且主通道干信比小于30 dB时,干扰对消后信噪比恶化小于0.6 dB,而且这一结果基本不受采样率的影响。所提出的理论性能近似计算公式可以为干扰对消算法的性能评价提供参考,采用LMS自适应滤波器的干扰对消在算法参数设置合理的情况下可以接近理论性能。     

Empirical modeling of money demand

This paper examines several central issues in the empirical modeling of money demand. These issues include economic theory, data measurement, parameter constancy, the opportunity cost of holding money, cointegration, model specification, exogeneity, and inferences for policy. Review of these issues at a general level is paralleled by discussion of specific empirical applications, including some new results on the demand for narrow money in the United Kingdom.The author is a staff economist in the Division of International Finance, Board of Governors of the Federal Reserve System, Washington, DC 20551 USA, and may be reached on the Internet at ericsson@frb.gov. The views in this paper are solely the responsibility of the author and should not be interpreted as reflecting the views of the Board of Governors of the Federal Reserve System, the Reserve Bank of Australia, or any other person associated with the Federal Reserve System or the Reserve Bank of Australia. I am grateful for the generous hospitality of the Reserve Bank of Australia, where I was on secondment when this research was begun. I also wish to thank Tony Brennan, Gordon de Brouwer, Julia Campos, Ed Nelson, Jerome Fahrer, Jon Faust, Steve Grenville, David Hendry, John Irons, Katarina Juselius, Neva Kerbeshian, Helmut Lütkepohl, Dieter Nautz, Athanasios Orphanides, Kevin Prestwich, Robert Subbaraman, Timo Teräsvirta, Jenny Wilkinson, Jürgen Wolters, and two anonymous referees for helpful comments and discussions. All numerical results were obtained using PcGive Professional Version 9.0; see Doornik and Hendry (1996). This paper is a condensed version of Ericsson (1998), which provides additional empirical and analytical examples and more extensive references. The data may be obtained from the Internet at http://wotan.wiwi.hu-berlin.de/oekonometrie/engl/data.html.     

论转型时期我国区域政策的目标取向及其调整思路

本文通过对我国现行区域经济政策体系的分析评价、认为随着地区经济发展格局以及区域经济运行机制的相应变化。区域经济政策目标转型十分必要。协调发展、效率与公平兼顾将成为下一阶段我国区域经济政策的主要目标取向。为了实现这种目标转型、重新调整我国的区域经济政策思路势在必然。     

采用图像处理的跳频信号参数盲估计

针对短波复杂信道环境下的跳频信号参数估计问题,提出了一种基于图像处理的跳频信号参数盲估计算法。该算法在时频分析的基础上采用灰度共生矩阵提取信号的纹理特征,通过对纹理特征量的分割实现信号与背景噪声的分割,并运用形态学滤波去除二值化后产生的椒盐噪声;然后根据连通区域标记得到的各个信号在时频图中的位置信息来聚类,从而去除定频、突发等干扰信号,分选出跳频信号;最后根据分选出的跳频信号提取其跳频频线并进行修正,估计出跳频信号的跳周期、跳变时刻和跳频频率。仿真实验表明,该算法切实有效,能够在较低的信噪比条件下精确地估计出跳频信号的参数。     

The impact of energy-exporting countries’ EPUs on China’s energy futures investors: Risk preference,investment position and investment horizon

This study brings some new insights into EPU risk management. By categorizing China’s energy futures (CEF) investors by risk preference, investment position and investment horizon, we identify how EPU in four energy-exporting countries affects CEF investors. The Russian EPU mainly produces influence on short-run investors and risk-seeking investors. The Australian EPU affects risk-seeking investors heavily, while the Brazilian EPU acts on risk-seeking investors with short positions. In terms of China’s coking coal futures, changes in Russian EPU generate the weakest impact on various types of investors, while the US EPU affects medium-run risk-averse and long-run investors. The Australian EPU’s impact on investor types covers a wide range, while the Brazilian EPU affects short-run risk-averse and long-run investors. Moreover, for medium-run CEF investors, energy-exporting countries’ EPU risk characteristics is most dynamic. Changes in the EPU risk impact type mainly occurred during the US-China trade war and the outbreak of COVID-19.     

一种稀疏重建的多基地雷达多目标定位算法

采用距离和信息的多基地雷达多目标投影定位算法中，距离向脉冲压缩后分辨率降低，需要已知空间中目标个数。针对此问题，提出了一种稀疏重建的多基地雷达多目标定位方法。该方法利用多个接收机中目标稀疏度相同的特点，通过构造平均重构残余误差变化率和平均散射系数变化率作为正交匹配追踪(OMP)算法迭代终止判定条件，自适应地终止OMP算法的同时获得稀疏重建信号以及信号稀疏度的估计值，提高了距离向分辨率，获得了对空间中目标个数的估计。仿真实验表明所提算法有效抑制了距离向主瓣展宽和旁瓣串扰，提高了距离向分辨率。同时，所提算法在不同噪声环境下能准确估计空间中目标个数并提取其空间位置，实现对空间中目标的准确定位。     

基于前向结构的高动态突发信号载波同步算法

为实现高动态突发通信系统载波快速同步，提出了一种新的基于前向结构的突发信号载波同步算法，采用多级处理方案分级实现多普勒变化率、多普勒频偏及载波相位的估计及恢复。理论分析及数值仿真表明，在高动态低信噪比条件下，新算法的载波同步信噪比损失小于1 dB，且对多普勒变化率及信号电平参数不敏感，实现复杂度低，能够满足高实时性应用需求。     

Z28 80A型滚丝机液压系统的改造

Ｚ２８ ８０Ａ型滚丝机的液压系统采用节流调速方式，系统功率损失大，传动速度不稳定；采用容积节流调速方式，并在系统中加装压力补偿器，则系统速度稳定性好，且有明显的节能效果