采用改进型AlexNet的辐射源目标个体识别方法

针对辐射源目标精确识别需求,结合以深度学习为代表的机器学习理论技术,提出将改进型AlexNet作为特征提取器,实现目标细微特征提取固化,形成智能化识别网络模型。以广播式自动相关监视（ADS-B）信号为实验对象,在机场实地采集了13个目标的ADS-B脉冲信号数据作为辐射源目标个体识别的训练和测试样本,利用AlexNet和改进的AlexNet验证了算法的有效性。结果表明,改进的AlexNet网络训练时间更快,综合识别率达到98.32%.     

鸟类目标微多普勒分析及参数估计

鸟类扑动的翅膀产生的微多普勒包含了目标的尺寸与微动特征信息,可用于鸟类目标参数估计,对探鸟雷达目标识别具有重要意义。首先建立鸟类目标雷达回波模型,推导了鸟翅膀散射点的微多普勒数学表达式,并通过计算回波的自相关函数估计目标扑翼频率;然后对微多普勒表达式进行泰勒级数展开,利用展开系数与扑翼幅度之间的关系得到扑翼幅度的估计值;最后根据半翼展与微多普勒谱宽之间的关系得到半翼展的估计值。仿真实验证明了所提方法的有效性和抗噪性：对扑翼幅度大于30??、半翼展大于0.3 m的目标,在信噪比高于0 dB的噪声环境下估计精度高。     

基于目标值的土地警素指标的预警研究 ——以上海市土地类指标为例

研究目的:探寻基于目标值的土地运行关键指标预警研究的方法,及时提出警戒信息与调控措施。研究方法:采用趋势预测法对警素指标的未来值进行预测,用年均增长率函数倒推法确定目标值倒推值,结合预测值与目标值倒推值确定2015—2020年弹性警界线,采用统计误差理论所得出3σ法则来确定警度界限的区间,采用景气信号灯法判别警情,黄色信号灯表示轻警、红色信号灯重警,采用情景分析法分析不同减量化目标下警情的变化趋势。研究结果:上海市建设用地总规模若按减量递增10%,则2018年后需要保持零增长,若减量递增30%,则增量还有一定上行空间;工业用地占比的预测值在未来5年内都处于红色预警,但警情有较为合理的自下降趋势。研究结论:建设用地应遵循"五量并举"的调控思路,努力实现规划建设用地"负增长"目标;而工业用地则通过加强分类引导,采取二次开发、复合利用等措施,优化用地结构,使工业用地占比回落到正常区间。单一警素指标预警适用于时间序列较长且有目标值的指标,未来的研究重点应在单项预警的基础上,构建以土地要素为核心的多要素安全综合预警体系。     

防沙治沙贵在综合 重在林业 关键在政府——《省级政府防沙治沙目标责任考核办法》析

2009年出台的《省级政府防沙治沙目标责任考核办法》,是我国继计划生育、保护1.2亿hm2耕地和节能减排后又一个对省级政府要进行量化考核的重要工作。论述了《办法》出台的必然性,归纳总结了《办法》的特点,阐述了《办法》的重要意义,提出了下一步具体实施还要提高认识、理清思路和明确责任。     

证券分析师估值模型选择偏好及其对目标价的影响研究——基于企业特征角度

以2017—2020年证券分析师研报为依据,将分析师估值模型选择偏好与分析师目标价结合探讨,并率先提出目标价投资参考价值这一全新概念且对其评估方法进行设计。研究发现,分析师存在特定的估值模型类型偏好,并且在不同行业中偏好不同的估值模型。然而,分析师偏好的估值模型不一定能够生成质量良好的目标价。对于不同特征的企业,分析师存在迥然各异的估值模型选择偏好,该偏好对目标价具有显著影响。结论可帮助分析师优化估值模型选择,提高目标价质量。     

A Jump-diffusion Model for Exchange Rates in a Target Zone

We propose a simple jump-diffusion model for an exchange rate target zone. The model captures most stylized facts from the existing target zone models while remaining analytically tractable. The model is based on a modified two-limit version of the C OX , I NGERSOLL and R OSS (1985) model. In the model the exchange rate is kept within the band because the variance decreases as the exchange rate approaches the upper or lower limits of the band. We also consider an extension of the model with parity adjustments, which are modeled as Poisson jumps. Estimation of the model is by GMM based on conditional moments. We derive prices of currency options in our model, assuming that realignment jump risk is idiosyncratic. Throughout, we apply the theory to EMS exchange rate data. We show that, after the EMS crisis of 1993, currencies remain in an implicit target zone which is narrower than the officially announced target zones.     

Corporate Stock and Bond Return Correlations and Dynamic Adjustments of Capital Structure

This paper analyses the effects of dynamic correlations between stock and bond returns issued by the same firm on the speed of adjustment towards target leverage. The results show that the estimated correlations are time varying, show persistence and differ among firms. Analysis of the potential explanatory variables reveals that the correlations decrease with negative expectations about future aggregate risks, but only for firms with a low default probability. In contrast, correlations are positively associated with specific risk measures, especially idiosyncratic stock risk and financial leverage. The positive relationship between the correlations and the leverage ratio suggests that target leverage can be achieved faster when the stock–bond correlation is high. Our results show that this is the case.     

任务型教学法和传统3P教学在阅读课中的对比

任务型教学法在提高学生独立思考，应用语言表达自己思想和全面看问题方面的确有3P教学所不能及的效果。高职英语阅读教学更需要引入任务型范式来提高其英语应用能力。     

Reactions to Shocks and Monetary Policy Regimes: Inflation Targeting Versus Flexible Currency Board in Sub‐Saharan Africa

The paper examines the monetary policy actions through which central banks in sub‐Saharan Africa have tried to eliminate the negative impacts of the shocks facing their economies. We compare two different monetary policy regimes: a currency board regime (in the CFA zone) and an inflation targeting policy regime (Ghana and South Africa) when central banks respond to demand, supply, and fiscal shocks. We extend the usual forecasting and policy analysis system models to replicate the economic features of these economies during the period 2002–12 and to evaluate the impact of several policies in response to these shocks. We find that both policies are inappropriate in helping the economies escape from the effects of negative demand shocks, both are essential when negative shocks to primary balance occur, while inflation targeting dominates the currency board regime as a strategy to cope with positive shocks to inflation.     

我国货币政策中介目标研究——一个文献综述

近年来,一些西方发达国家相继放弃了货币供应量目标,转向了利率、通货膨胀等目标,进而在我国也引发了货币供应量能否继续充当货币政策中介目标的争论.本文认为,尽管大多数实证研究均已表明货币供应量作为中介目标的有效性正不断降低,然而从我国当前的经济金融发展情况来看,选择利率或通货膨胀目标还缺乏可行性.因此,我国面临的现实选择只能是继续以货币供应量为目标,同时稳步推进金融体系、金融制度的改革,为中介目标的转变奠定基础.