一种获取雷达目标一维距离像的方法

利用高分辨一维距离像进行目标识别在现代雷达中已成为一个重要的研究课题。本文基于雷达信号设计和互相关接收处理技术,研究了一种利用目标回波,逐次获取一维距离像的方法。与冲激雷达相比,这种方法能显著提高信噪比,并且这个方法的收敛速度快,一般迭代10次以内即达到稳定。     

TRADER TYPE EFFECTS ON THE VOLATILITY‐VOLUME RELATIONSHIP EVIDENCE FROM THE KOSPI 200 INDEX FUTURES MARKET

We investigate whether the trading activity generated by investors with different access to information and trading motives has positive or negative impact on index futures volatility. Surprises in non‐member institutional, individual and foreign investors' trading volume are positively associated with volatility in most of the cases. For member institutional investors, unexpected trading volume is positively related to volatility. Long‐run changes in the trading activity also affect volatility differently across trader types. Finally, allowing for time‐to‐maturity effects, surprises in open interest are associated with more volatility towards contract expiration, contrary to the negative effect we find during normal times.     

一维卷积神经网络用于雷达高分辨率距离像识别

针对人工提取高分辨率距离像（HRRP）优良特征比较困难的问题，研究了基于一维卷积神经网络（CNN）的HRRP识别方法。利用CNN具有分层学习特征的能力，训练CNN自动地从HRRP中学习有用的特征并分类。在仿真实验中描述了网络的相关配置，分析了不同激活函数、不同参数、不同网络结构的识别性能，对比了CNN与其他分类器的识别结果，用可视化特征图直观地说明了CNN通过卷积层能够学习到易于分辨的特征。实验结果表明CNN具有很好的识别性能。     

多站制连续波高精度测量体制研究

高精度测量体制直接关系到飞行试验能否获取完整的高精度测量数据。针对5种高精度测量体制，提出了选择测量体制的原则，从可靠度、精度、技术先进性、设备可实现性、使用方便性、靶场适应用性等方面进行论证，认为连续波多RR系统是一种较好的测量体制，并对该体制的关键技术难点的解决途径进行了分析。     

The Impact of Range Pricing on Marketing Time and Transaction Price: A Better Mousetrap for the Existing Home Market?

In various markets around the country, some real estate professionals are employing a new pricing strategy that involves marketing homes for sale with a price range rather than a single asking price. This strategy is often touted as a mechanism that will attract more potential buyers to look at a house and thus result in reduced marketing times for existing homes, with prices determined by competitive forces. The purpose of this study is to empirically examine whether houses using range pricing, often referred to as value range marketing, sell in the same amount of time and sell for similar prices as those marketed in the traditional manner. Two staged least squares with a correction for sample selection and Weibull duration models are used to test the hypotheses, employing a sample of 5,852 residential houses that were sold during the period January 1999 to December 2000. In contrast to claims of the strategy’s proponents, the results indicate that houses take longer to sell when using the range pricing strategy after controlling for physical characteristics and market conditions. Furthermore, there is no evidence that this strategy has any significant impact on transaction prices.     

我国外汇储备适度规模的理性思考

以2004年我国国际收支状况为例，综合运用相关理论，从进口用汇需求、外债还本付息用汇需求、外商直接投资利润返还汇出额、外汇平准基金、居民用汇需求、对外投资的用汇需求、满足特殊需要的外汇储备等方面进行分析，可得出我国外汇储备的适度规模区间，从而得出我国当前外汇储备充足但不过量的结论。     

航天测控站大动态控制的实现

介绍航天测控通信系统中首区测控站微波接收大动态控制的实现方法,采用“二状态”断续自动控制方案和高性能大动态控制模块。达到96 dB的大动态控制,实现了抗强信号互调、高灵敏度接收及和、差通道相位、增益的高一致性。     

Efficient modelling and forecasting with range based volatility models and its application

This paper considers an alternative method for fitting CARR models using the combined estimating functions (CEF) by showing its usefulness in applications in economics and quantitative finance. The associated information matrix for corresponding new estimates is derived to calculate the standard errors. Extensive simulation study is carried out to demonstrate its superiority relative to two other competitors: the linear estimating functions (LEF) and the maximum likelihood (ML). Results show that the CEF method is more efficient than the LEF and ML methods when the error distribution is mis-specified. Applying a real data set from financial market, we illustrate the applicability of the CEF method in practice and report some reliable forecast values for minimizing the risk in decision making process.     

俄罗斯卢布汇率政策实施机制

文章分析了俄罗斯为最终实现卢布汇率自由浮动的汇率政策目标的制度探索,认为其现已建立起一套机制复杂但运作灵活的卢布汇率形成机制。文章介绍了2013年10月以来俄罗斯完善卢布汇率制的主要措施,包括扩大卢布对双货币篮子汇率每日浮动的“中立区间”,在卢布对双货币篮子汇率每日浮动区间中增设“技术区间”,下调每日外汇干预的目标额度等。     

土地科学学科独立性研究——兼论土地科学学科体系研究思路与框架

研究目的:研究探讨并确定土地科学学科是否具有独立学科的本质属性,在此基础上提出土地科学学科体系研究思路与框架。研究方法:根据《中华人民共和国学科分类与代码国家标准(GB/T 13745-2009)》的定义,依据科学学方法,从讨论土地科学学科有无不可替代的核心理论和不可替代的研究域入手,研究土地科学学科的独立学科属性。研究结果:土地科学学科是一门具有不可替代的土地权籍核心理论,并与土地租价、土地可持续利用理论共同构成有机联系不可分割的核心理论轴,同时具有不可替代的3维3层3环耦合空间研究域的独立学科。研究结论:(1)借助逻辑和空间分析方法,提出的土地科学学科3维3层3环耦合空间研究域,揭示了土地科学学科的本质属性,从而解开了有关土地科学学科的多个重大难题。(2)通过有关土地科学学科发生、演进和发展趋势的研究分析,揭示了:1土地科学学科与相关学科交叉的本质,是由于人类不断提高土地生产力的内生要求牵引,引致土地科学学科研究域内生性扩张导致的交叉;2土地科学学科研究域是一个随着人类提高土地生产力而对应扩张的3维3层3环耦合空间域,且仍会伴随人类不断提高土地生产力的要求持续扩张。(3)通过有关不可替代核心理论及核心理论轴,3维3层3环耦合空间研究域及其形成,学科发生、演进和发展趋势的研究分析,提出了有关土地科学学科的完整系统学说。