我国鸭苗价格波动的周期性研究

在分析影响我国鸭苗价格周期性波动原因的基础上,利用X12季节调整法与H-P滤波模型法对我国鸭苗价格周期波动进行研究。结果表明:鸭苗价格波动具有周期性,周期平均长度为33个月,每个周期具有非对称性,每一周期的持续上涨时间低于持续下降时间。提出建立鸭苗生产的资格准入制度和标准许可证制度、合理控制鸭苗供给规模、保持国际和国内肉鸭市场信息畅通和加强肉鸭的疫病防治工作等相关的建议。     

双循环新发展格局下中国双向直接投资研究

构建以国内大循环为主体、国内国际双循环相互促进的新发展格局,是对未来中国经济发展路径做出的重大战略部署,作为连接国内国际双循环的纽带,双向直接投资的发展战略和路径面临重塑和调整。研究认为,应当以推动新时代科技创新和产业升级为目标,提高双向直接投资的质量,畅通供应链和产业链; 以“一带一路”倡议为依托,通过更高水平的双向投资带动中国与沿线国家贸易水平的提高; 建设高水平自贸区和自贸港,提高对外开放标准,更高质量吸引外资,提升参与国际大循环的技术含量和自主性; 在畅通要素流动领域,建立更加完善的现代化物流体系,建设更高标准的要素流通市场体系,降低制度性交易费用,提高生产率和对高质量外资的吸引能力。     

中国省份创新能力提升了出口韧性吗?——基于中国31个省份的面板数据分析

在国际政治、地缘政治和国际公共安全卫生事件对出口产生冲击的背景下,采取何种政策措施来应对外部冲击、保持出口稳定增长成为政府和企业面临的重要问题。借鉴区域经济韧性的测度方法,基于首次提出的出口韧性测度指标,利用《中国海关进出口统计数据库》测度了1999—2016年中国31个省份(除中国香港、澳门、台湾外)的出口韧性,结合《中国统计年鉴》省份层面的宏观数据,运用固定效应模型,考察了省份创新能力、出口韧性之间的关系和产业内在出口韧性的来源、决定机制。研究发现,省份创新能力的提升有利于提高其出口韧性,省份创新能力对不同地区的省份出口韧性存在异质性影响,在金融危机这一负向外部冲击下,省份创新能力的提升对出口韧性的提高存在显著促进作用。研究表明,要通过深化科技体制改革,加大对新兴产业的税收优惠政策力度,加速出口产业整体向创新驱动发展的转型升级,完善出口产品研发创新链条,促进企业完善人才培养机制等方式来提高省份创新能力,提高出口韧性和稳定出口优势。     

论市场交换的供给与需求、成本与收入双重属性(上)

本文试图以一种崭新的非均衡的供给与需求、成本与收入双重属性的市场交换概念,重新阐释市场交换问题。两个人在竞争市场上相互交换的两种不同商品,既是自己的供给商品,即自己生产、拥有、卖出的商品,又是对方的需求商品,即对方用供给商品买回的满足自己需要的商品,两个交换商品具有供给与需求双重属性,这种属性说明用什么交换什么;供给商品生产和交换消耗的费用称谓供给成本,简称成本,用成本买回的需求商品称谓需求收入,简称收入,两个成本交换后变成了两个收入,成本与收入也有双重属性,这种属性说明两种交换商品用多少成本换回多少收入。市场交换就是用供给交换需求,用成本交换收入,追逐收入大于成本的利润,避免收入小于成本的亏损,这就是市场交换机制。     

SEMIPARAMETRIC REGRESSION AND GRAPHICAL MODELS

Semiparametric regression models that use spline basis functions with penalization have graphical model representations. This link is more powerful than previously established mixed model representations of semiparametric regression, as a larger class of models can be accommodated. Complications such as missingness and measurement error are more naturally handled within the graphical model architecture. Directed acyclic graphs, also known as Bayesian networks, play a prominent role. Graphical model-based Bayesian 'inference engines', such as bugs and vibes , facilitate fitting and inference. Underlying these are Markov chain Monte Carlo schemes and recent developments in variational approximation theory and methodology.     

战略技术联盟构建竞争优势:专利许可与专利互换范例

从战略联盟的角度分析了一种建立竞争优势的途径.通过模型分析和实例解割,揭示出企业可以通过一系列战略联盟组合将自己的核心竞争力转化为可以获得利益的竞争优势.阐明了核心竞争力是联盟的基础,通过联盟可以转化为竞争优势;战略联盟是获取竞争优势的重要手段之一.     

基于人力资源管理价值链视角的“用工荒”现象分析

本文基于人力资源管理价值链的视角,分析了政府和企业在农民工这一特殊人力资源类型的价值创造、价值评价和价值分配的三个环节管理中存在的问题。这些问题最终导致了＂用工荒＂现象的产生。政府层面存在的主要问题有：在价值评创造环节中,缺乏对低端劳动力群体的规划、建立统一的劳动力市场和对农民工技能培训经费的投入不足;在价值评价环节,缺乏对技能人才的评价机制;在价值分配环节,对农民工利益保障的立法不完善且执法不严。企业层面存在的主要问题有：在价值创造环节,只重使用,不重培养;在价值评价环节,缺乏多种评价手段;在价值分配环节,企业发放给农民工的薪酬福利低,针对以上问题,从政府和企业两个层面,提出了相应的解决对策。     

Adaptive multiple importance sampling for Gaussian processes

In applications of Gaussian processes (GPs) where quantification of uncertainty is a strict requirement, it is necessary to accurately characterize the posterior distribution over Gaussian process covariance parameters. This is normally done by means of standard Markov chain Monte Carlo (MCMC) algorithms, which require repeated expensive calculations involving the marginal likelihood. Motivated by the desire to avoid the inefficiencies of MCMC algorithms rejecting a considerable amount of expensive proposals, this paper develops an alternative inference framework based on adaptive multiple importance sampling (AMIS). In particular, this paper studies the application of AMIS for GPs in the case of a Gaussian likelihood, and proposes a novel pseudo-marginal-based AMIS algorithm for non-Gaussian likelihoods, where the marginal likelihood is unbiasedly estimated. The results suggest that the proposed framework outperforms MCMC-based inference of covariance parameters in a wide range of scenarios.     

Optimal design of the adaptive exponentially weighted moving average control chart over a range of mean shifts

The adaptive exponentially weighted moving average (AEWMA) control chart is a smooth combination of the Shewhart and exponentially weighted moving average (EWMA) control charts. This chart was proposed by Cappizzi and Masarotto (2003) to achieve a reasonable performance for both small and large shifts. Cappizzi and Masarotto (2003) used a pair of shifts in designing their control chart. In this study, however, the process mean shift is considered as a random variable with a certain probability distribution and the AEWMA control chart is optimized for a wide range of mean shifts according to that probability distribution and not just for a pair of shifts. Using the Markov chain technique, the results show that the new optimization design can improve the performance of the AEWMA control chart from an overall point of view relative to the various designs presented by Cappizzi and Masarotto (2003). Optimal design parameters that achieve the desired in-control average run length (ARL) are computed in several cases and formulas used to find approximately their values are given. Using these formulas, the practitioner can compute the optimal design parameters corresponding to any desired in-control ARL without the need to apply the optimization procedure. The results obtained by these formulas are very promising and would particularly facilitate the design of the AEWMA control chart for any in-control ARL value.     

Monitoring the coefficient of variation using a variable sample size and sampling interval control chart

This article proposes a CV chart by using the variable sample size and sampling interval (VSSI) feature to improve the performance of the basic CV chart, for detecting small and moderate shifts in the CV. The proposed VSSI CV chart is designed by allowing the sample size and the sampling interval to vary. The VSSI CV chart's statistical performance is measured by using the average time to signal (ATS) and expected average time to signal (EATS) criteria and is compared with that of existing CV charts. The Markov chain approach is employed in the design of the chart.