贝叶斯方法在二维目标定位中的应用

本文对如何运用贝叶斯方法,以一维方式采集资料,进行二维目标定位作了一些探讨。实验中,运用光电计测定出发射和接收红外二极管的模式,通过分析建立起物体的二维模型方程,然后运用贝叶斯方法,估计出物体在坐标中的水平位置和垂直距离。进而验证了这种基于贝叶斯方法的二维物体定位算法。这为以后研制具有较强实用性的地雷探测仪或者是其它的不方便进入目标区域情况下的应用提供了方法上的依据。     

What is the major determinant of cross-border banking flows?

This study examines the major determinant of cross-border credit flows through global banks across 70 countries. Employing a Bayesian dynamic latent factor model, we decompose volatilities of banking flows into the contribution of a global common factor, regional common factor, and country-specific factor. The results indicate that the global and regional common factor explains about 40–50 percent of volatility in overall cross-border banking flows. In particular, the contribution of the global common factor increased in the 2000s. Simultaneously, main determinants are largely heterogeneous across countries: this implies that the desirable policy response to credit inflows may differ for each host country.     

Forecasting portfolio-Value-at-Risk with nonparametric lower tail dependence estimates

We propose to forecast the Value-at-Risk of bivariate portfolios using copulas which are calibrated on the basis of nonparametric sample estimates of the coefficient of lower tail dependence. We compare our proposed method to a conventional copula-GARCH model where the parameter of a Clayton copula is estimated via Canonical Maximum-Likelihood. The superiority of our proposed model is exemplified by analyzing a data sample of nine different bivariate and one nine-dimensional financial portfolio. A comparison of the out-of-sample forecasting accuracy of both models confirms that our model yields economically significantly better Value-at-Risk forecasts than the competing parametric calibration strategy.     

政府在耕地减少中的责任和在耕地保护中的作为

集成曲线估计模型和灰色数列模型,研究耕地总量在1983-2006年间的变化过程以及在2010～2020年间的变化态势,分析政府行为在耕地总量减少中的责任和在保护耕地中的作为.研究结果:2020年耕地总量可能低于新的耕地红线,政府对耕地减少负有不可推卸的责任.     

The Benefit Function Approach to Modeling Price-Dependent Demand Systems: An Application of Duality Theory

In this article, we advocate more extensive use of the benefit function in specifying price-dependent or inverse demand models. We demonstrate how duality theory may be used to establish the interrelationships between the Marshallian (or Hicksian) inverse demands and Luenberger's adjusted price functions, allowing estimable inverse demands to be derived directly from a benefit function. We estimate two systems of inverse demands for Japanese quarterly fish consumption. Results indicate that the procedures and methods employed here appear promising, and may prove beneficial for quantity and welfare analysis when modeling systems of inverse demand functions.     

大频偏卫星扩频信号的基带处理算法的FPGA实现

多普勒频偏一直是卫星通信中不可忽视的消极因素。针对多路混叠的卫星扩频信号下变频以后所产生的大多普勒频偏,在匹配滤波结构中采取改进的部分相关算法,在基于并行导频的信道估计中根据信道状况改变估计长度,实现了大频偏下卫星扩频信号的基带处理。     

长春市土地征用补偿区片综合价格的测算及应用分析

在详细介绍长春市土地征用补偿区片综合价格测算的基础上,简单介绍了长春市征地区片划分及结果.采用历史征地案例价格比较法与产值倍数法相结合的思路,初步测算了长春市征地补偿综合价格.最后对测算结果从总体价格水平及空间差异上进行了对比分析,并对此次测算成果的应用提出了建议.     

宽松的环境政策能吸引更多的外商直接投资吗——基于中国工业省级面板数据的分析

利用我国1997~2009年的工业省级面板数据和动态面板GMM估计方法,考察了相对宽松的环境政策是否是吸引FDI的主要原因。研究发现,环境政策较宽松的地区能够吸引更多的外资流入,但这种影响并不大,所以,以降低环境标准、牺牲环境为代价来吸引FDI不是明智之举;与东、中部地区相比,西部在吸引FDI上处于明显劣势,这在一定程度上加剧了我国经济结构的失衡。     

水源地突发水污染政府应急预留水量需求预测

近年来,随着工业化和产业化的快速发展,水源地突发水污染事件频发。为应对紧急情况下的水资源非常规需求,保障经济社会稳定发展,政府需要安排一部分应急预留水量。如何合理预测政府应急预留水量的规模是一个值得探讨的课题。提出了一种基于案例推理技术的政府应急预留水量需求预测方法,具体思路是:借助于案例库,利用主成分分析法从众多影响水源地突发水污染事件的因素中提取出两两不相关的因子,以此作为案例的特征属性,基于加权曼哈顿距离测算相似度,依此得到匹配案例,进而测算政府应急预留水量。以太湖流域常州地区水源地为例,进行政府预留水量需求量的预测与分析。该方法可以为政府应急预留水量的配置、储备等提供相关理论知识。     

Adoption of farm‐based irrigation water‐saving techniques in the Guanzhong Plain,China

This article analyses adoption of farm‐based irrigation water saving techniques, based on a cross‐sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm‐based water‐saving technique. However, the traditional, inefficient techniques border and furrow irrigation are still prevalent whereas the use of advanced, more efficient techniques is still rather rare. We develop and estimate an adoption model consisting of two stages: awareness of water scarcity and intensity of adoption. We find that awareness of water scarcity and financial status enhance adoption of more advanced techniques whereas access to better community‐based irrigation infrastructure discourages it. We furthermore find both community‐based irrigation infrastructure and farm‐based irrigation water‐saving techniques have mitigating effects on production risk. From the results it follows that adoption can be stimulated via financial support and via extension aimed at enhancing awareness of water scarcity.