面向石油机械产品生命周期的网络化制造的研究

网络化制造是在网络经济下发展起来的先进制造模式,而产品生命周期管理(Product Life-cycle Management,PLM)是针对制造业的扩展型企业解决方案。对网络化制造下石油机械产品生命周期管理的需求进行了具体分析,进而提出了面向产品生命周期管理的网络化制造模式下的特点,在此基础上,总结出了实现此种模式的关键技术:分布式网络通讯技术、基于PLM的工作流程管理、基于网络的异构数据管理及复杂系统建模策略与方法等。     

Heterogeneous information exposure and technology adoption: the case of tissue culture bananas in Kenya

Classical innovation adoption models implicitly assume homogenous information flow across farmers, which is often not realistic. As a result, selection bias in adoption parameters may occur. We focus on tissue culture (TC) banana technology that was introduced in Kenya more than 10 years ago. Up till now, adoption rates have remained relatively low. We employ the average treatment effects approach to account for selection bias and extend it by explicitly differentiating between awareness exposure (having heard of a technology) and knowledge exposure (understanding the attributes of a technology). Using a sample of Kenyan banana farmers, we find that estimated adoption parameters differ little when comparing the classical adoption model with one that corrects for heterogeneous awareness exposure. However, parameters differ considerably when accounting for heterogeneous knowledge exposure. This is plausible: while many farmers have heard about TC technology, its successful use requires notable changes in cultivation practices, and proper understanding is not yet very widespread. These results are also important for other technologies that are knowledge‐intensive and require considerable adjustments in traditional practices.     

投资者异质信念与公司股利支付研究

在逻辑分析和模型推理的基础上,本文利用我国沪深两市2009-2010年上市公司股利政策的数据,探讨了投资者异质信念与上市公司股利支付倾向之间的关系。研究表明:当投资者异质信念越大时,上市公司支付股利的可能性越小。     

基于ADS-B趋势信息的民航飞机跟踪算法

为了有效提高飞机的跟踪精度,获得准确的飞机监视信息,针对民航飞机运行 的特点以及ADS-B信息的特征,充分利用ADS-B趋势信息报告和当前统计模型的优点,提出了 一 种基于ADS-B趋势信息的当前统计模型改进算法。该算法能够将直线运动和转弯机动飞行中 的跟踪误差都稳定在60 m左右,证明了该算法适用于所有飞行阶段,提高了当前统计模 型跟踪算法的精度和适用性。     

基于极化电磁波的飞行器姿态角估计新方法

提出使用单矢量传感器进行飞行器姿态角估计的新方法,安装在飞行器平台的单电磁 矢量传感器接收来自基站的极化电磁波信号,用MUSIC算法进行信号DOA和极化参数估计,得 到机体坐标系到地理坐标系的转换矩阵即飞行器姿态矩阵,最终估计飞行器姿态角。Matlab 仿真验证了该方法的有效性,姿态角估计误差在15°内,满足飞行器控制的要求。     

基于Web Service技术实现大型系统集成

提出了一套解决目前异构系统集成的有效方案。该方案基于先进WebService技术,能够很好地克服异构系统之间平台、语言、协议的差异,实现无缝、松耦合的系统集成。     

异质性企业、控制权配置与公司价值——基于稳定制度背景下中国上市公司非平衡面板数据的实证

经验实证对于控制权的性质、控制程度如何影响公司价值的研究无法获得一致性结论,原因是研究中对企业与制度异质性特征关注不够。本研究基于稳定制度背景下,运用2003～2010年度中国资本市场上市公司非平衡面板数据,就中国企业的公司控制权配置中大股东控制性质与控制规模对公司价值的影响展开实证研究。研究充分考虑上市企业的异质性,设计丰富的控制变量对异质性因素进行控制,同时在价值测量中运用多个测量工具,提升研究的稳健性。研究显示,在中国背景下大股东的控制性质与控制规模对公司价值的影响是复合性的。     

Export quality differentiation under credit constraints

This paper studies the effect of credit constraints on the choice by small and medium-sized enterprises to export goods of higher quality relative to their domestically sold output (quality differentiation). The empirical analysis employs detailed firm-level data on product characteristics and credit scores. Credit constraints are found to be negatively associated with export quality differentiation. Firms reporting a deterioration of the credit score by a standard deviation are 36% less likely to pursue quality differentiation. The negative relation between credit constraints and quality differentiation is stronger for firms exporting to distant markets.     

Asset pricing with heterogeneous beliefs and illiquidity

This paper studies the equilibrium price of an asset that is traded in continuous time between N agents who have heterogeneous beliefs about the state process underlying the asset's payoff. We propose a tractable model where agents maximize expected returns under quadratic costs on inventories and trading rates. The unique equilibrium price is characterized by a weakly coupled system of linear parabolic equations which shows that holding and liquidity costs play dual roles. We derive the leading‐order asymptotics for small transaction and holding costs which give further insight into the equilibrium and the consequences of illiquidity.     

Teaching About Heterogeneous Response Models

Individuals vary in their responses to incentives and opportunities. For example, additional education will affect one person differently than another. In recent years, econometricians have given increased attention to such heterogeneous responses and to the consequences of such responses for interpreting regression estimates, especially regression estimates based on instrumental variables. In this article, the author offers illustrative cases with which to introduce masters-level and advanced undergraduate students to the interpretive challenges posed by heterogeneous responses in econometric models.