S波段三次宽带倍频器

本文介绍了一种Ｓ波段宽带高效微波倍频器的设计方法，给出了其印刷电路及性能指标。     

A look into the factor model black box: Publication lags and the role of hard and soft data in forecasting GDP

We derive forecast weights and uncertainty measures for assessing the roles of individual series in a dynamic factor model (DFM) for forecasting the euro area GDP from monthly indicators. The use of the Kalman smoother allows us to deal with publication lags when calculating the above measures. We find that surveys and financial data contain important information for the GDP forecasts beyond the monthly real activity measures. However, this is discovered only if their more timely publication is taken into account properly. Differences in publication lags play a very important role and should be considered in forecast evaluation.     

一种用于DS扩频信号非相干检测的差分延迟SAW相关器

本文介绍了用于ＤＰＳＫ调制的ＤＳ扩频信号非相干检测的一种ＳＡＷ器件的设计方法。对所研究的差分延迟功能均集于单一器件中。因为没有采用独立的延迟线，故消除了带限影响，ＤＰＳＫ解调器延迟支路无插入损耗。     

PBG结构在微波领域的应用

20世纪80年代末出现的光子晶体是一种具有光子带隙的新材料，其特有的性质使得光子晶体具有广泛的应用前景。本文介绍了光子晶体的概念，综述了光子带隙结构在微波领域的典型应用和研究进展。     

雷达杂波谱参量估计及其在自适应滤波中的应用

本文结合自适应滤波技术在地面监视雷达信号处理中的工程应用,提出一种利用自相关法实时估计杂波谱参量,并根据统计参量自适应控制滤波器的方法.采用门限判决法,改善了杂波空域分布不均匀和目标引入对杂波谱参量估计带来的误差.文中特别对自适应滤波技术的实际工程应用问题进行分析讨论.经理论分析和计算模拟论证了该方法的正确性和可行性.最后结合工程实践,给出采用TMS32020数字信号处理器实现杂波谱参量估计和自适应控制滤波器的方案设想.     

外贸顺差、贸易筛选与就业关系研究——基于月度数据的再检验

本文利用2001-2009年的对外贸易月度数据,考察了中国出口与外贸顺差对就业水平的影响。研究表明,在暂时不考虑进口的情况下,出口规模的扩大对就业依然产生正向冲击;但是考虑进口后,外贸顺差的就业效应却呈现出先促进后抑制的效应。因此,传统的菲利普斯曲线机制认为的外贸顺差促进就业的观点可能需要重新修正,而Helpman等提出的"贸易筛选"机制在中国当前的外贸顺差规模下,将在劳动力市场上发挥主要作用。鉴于此,中国应在进一步提高出口规模和质量的同时,重视进口对经济发展的促进作用,将外贸顺差规模控制在合理范围。     

公积金制度对上海住房市场发展的影响研究

为研究住房公积金制度在上海住房市场发展过程中的作用,笔者通过运用状态空间模型与卡尔曼滤波解法的实证分析认为,住房公积金制度对上海市住房市场的量价都有很大的影响。在有力提高了居民住房消费能力的同时,也是助推房价泡沫化的一个重要因素,这种助推力主要源于政府拆迁。因此目前的房地产调控政策应该进行微调,以充分发挥公积金制度的积极作用和抑制其不利影响,进一步完善我国的住房保障体系。     

Nowcasting China’s GDP Using a Bayesian Approach

Real time nowcasting is an assessment of current-quarter GDP from timely released economic and financial series before the GDP figure is disseminated. Providing a reliable current quarter nowcast in real time based on the most recently released economic and financial monthly data is crucial for central banks to make policy decisions and longer-term forecasting exercises. In this study, we use dynamic factor models to bridge monthly information with quarterly GDP and achieve reduction in the dimensionality of the monthly data. We develop a Bayesian approach to provide a way to deal with the unbalanced features of the dataset and to estimate latent common factors. We demonstrate the validity of our approach through simulation studies, and explore the applicability of our approach through an empirical study in nowcasting the China’s GDP using 117 monthly data series of several categories in the Chinese market. The simulation studies and empirical study indicate that our Bayesian approach may be a viable option for nowcasting the China’s GDP.     

How government-led land consolidation efforts achieve grain production stability? An empirical analysis in Hubei Province,China

China has been conducting massive land consolidation (LC) projects since the late 1990s to ensure national food security which has been one of the common issues in the world. How the implementation of LC projects affects grain production stability is a question should be answered. Basing on an empirical analysis at the county level in Hubei Province, China, this paper separates the trend component and the fluctuation component from a time series of grain production over 1991-2016 using the H-P filtering method. Then we estimate the impacts of LC projects and climate change on the trend and fluctuation rate of grain production for the entire Hubei Province. Moreover, the effects on the production of different major crops for the central, eastern, southwestern, northwestern and northern areas are also examined, respectively. The results show that: (1) the production trends for five subareas and the whole area all have followed a trajectory of “increase-decrease-increase” from 1991 to 2016. The magnitude of fluctuation rate was large but became smaller in recent years. (2) The contribution of LC to the long-term trends of grain production for the entire samples in Hubei Province mainly benefits from the growth in the cultivated land area through LC; more LC investment and newly-added arable land area promote the sudden increase in grain production above the long-term trends, while the impacts of LC area are negative. (3) The impacts of LC on the major crop production vary across areas. LC exerts significant impacts on the production of major crops in the central and eastern Hubei, and this effect persists to the following year. Similarly, this influence also exists in the southwestern and northern area, while becomes insignificant in the following year. No significant effect of LC variables is found in the northwestern area. These findings may provide reference for the government to address LC inefficiency and food security problems, and an effective and innovative mechanism combining the agricultural production, land consolidation and meteorological factors needs to be established to ensure food security and long-term and stable agricultural production. In addition, the regional difference in natural conditions and LC orientations should also be considered.     

中国单一货币供给规则

中国货币供应量和经济目标相关程度高,具有较好的可测性、可控性;在中国实行有规则、透明度高、连贯性强的单一货币规则是可行的;严格执行货币供给量与相关经济目标挂钩的数量型货币政策,有助于确保物价稳定和经济平稳增长。