Modeling asymmetric price transmission in the European food market

In this study, we employ a multivariate panel error correction model (PVECM) to investigate asymmetric price transmission among the farm, processor, and retail segments of the European food supply chain for the 2005–2016 period. The results indicate that, in both the long- and short-run, retail prices respond more strongly to processor price increases than decreases and the same occurs for processor prices due to farm price changes. Thus, the findings demonstrate the presence of positive asymmetric price transmission in the European food supply chain. Finally, the results of the present study indicate that the food price pass-through varies greatly across product category and across countries, and that the pass-through to producer prices is greater than that to consumer prices.     

双选信道下一种基于混沌交织的FBMC系统

高速移动环境下，无线信道具有时频双选性衰落的特性，使得滤波器组多载波(Filter Bank Multi-carrier，FBMC)系统产生长突发差错。将一种基于Baker映射的混沌交织算法应用在滤波器组多载波系统中，根据混沌密钥对发送数据进行分块和重新排列，按照Baker映射规则完成数据交织。此方法可以将长突发差错变为单突发差错，结合卷积编码能有效地纠正双选信道产生的长突发差错。仿真结果表明，在双选择信道中，基于混沌交织的滤波器组多载波系统误比特率性能优于传统基于块交织的滤波器组多载波系统。     

输送机中心轴线标定及测量精度分析

通过对带式输送机安装中心轴线标定方法进行理论分析,推导出边长和角度实测的精度相关公式,同时输送机的施工安装工艺对测量标定中心轴线提出了较高的要求,为我们提出了在实际工作中的具体做法和应注意的几个问题。     

Forecasting Bordeaux wine prices using state-space methods

Generic Bordeaux red wine (basic claret) can be regarded as being similar to an agricultural commodity. Production volumes are substantial, they are traded at high frequency and the quality of the product is relatively homogeneous. Unlike other commodities and the top-end wines (which represent only 3% of the traded volume), there is no futures market for generic Bordeaux wine. Reliable forecasts of prices can to large extent replace this information deficiency and improve the functioning of the market. We use state-space methods with monthly data to obtain a univariate forecasting model for the average price. The estimates highlight the stochastic trend and the seasonality present in the evolution of the price over the period 1999 to 2016. The model predicts the path of wine prices out of sample reasonably well, suggesting that this approach is useful for making reasonably accurate forecasts of future price movements.     

玻璃纤维增强塑料夹砂管初始力学性能检测的研究

由玻璃纤维增强塑料夹砂管的环刚度、刚度等级概念分析了环刚度设计与检测的基本方法,探讨挠曲水平、轴向拉伸强力和环向拉伸强力检测方法,比较分析了各种方法的优缺点与适用范围,对理解及掌握玻璃纤维增强塑料夹砂管初始力学性能的概念及相关检测方法具有一定参考意义。     

天然气输送支干线生产管理探讨

天然气输送管线安全运行面临风险,本文主要对天然气输送管线生产管理进行探讨。     

Varying Coefficient Regression Models: A Review and New Developments

Varying coefficient regression models are known to be very useful tools for analysing the relation between a response and a group of covariates. Their structure and interpretability are similar to those for the traditional linear regression model, but they are more flexible because of the infinite dimensionality of the corresponding parameter spaces. The aims of this paper are to give an overview on the existing methodological and theoretical developments for varying coefficient models and to discuss their extensions with some new developments. The new developments enable us to use different amount of smoothing for estimating different component functions in the models. They are for a flexible form of varying coefficient models that requires smoothing across different covariates' spaces and are based on the smooth backfitting technique that is admitted as a powerful technique for fitting structural regression models and is also known to free us from the curse of dimensionality.     

浅谈测量员如何更好更快地提高业务水平

测量作为服务于国民经济建设的重要行业，随着传统测绘技术向数字化测绘技术转化，它表现出复杂性及多样性，当我们面对一项新的测量任务时，除了传统学习模式之外，我们该如何更好地提高自身地业务水平呢？本文结合作者工作经验论述了上述问题，为测量同行提供一些建议及指导。     

Small Area Estimation for Disease Prevalence Mapping

Small area estimation (SAE) entails estimating characteristics of interest for domains, often geographical areas, in which there may be few or no samples available. SAE has a long history and a wide variety of methods have been suggested, from a bewildering range of philosophical standpoints. We describe design-based and model-based approaches and models that are specified at the area level and at the unit level, focusing on health applications and fully Bayesian spatial models. The use of auxiliary information is a key ingredient for successful inference when response data are sparse, and we discuss a number of approaches that allow the inclusion of covariate data. SAE for HIV prevalence, using data collected from a Demographic Health Survey in Malawi in 2015–2016, is used to illustrate a number of techniques. The potential use of SAE techniques for outcomes related to coronavirus disease 2019 is discussed.     

Effects of subject pool culture and institutional environment on corruption: Experimental evidence from Albania

This research uses experimental methods to investigate whether subject pool culture and institutional environment have an effect on participants’ corrupt behavior in the laboratory. While we find that subject pool culture does not affect the overall magnitude of corruption of laboratory participants, it does affect the likelihood of corruption and its distribution. Additionally, we find that the effect on corrupt behavior differs with the framing of the experiment’s instructions. Interestingly, in the context of a weak rule of law and high levels of corruption, loaded negative instructions positively affect corrupt behavior of firms and public officials. Previous research in the context of a country exhibiting a strong rule of law and low levels of corruption finds no framing effects. We also find that increasing the probability of detection significantly reduces corruption as measured by the amount of the bribes offered/accepted and the probability of offering/accepting a bribe. Finally, we find that individual risk preferences negatively affect the level of corrupt behavior.