不同企业下物流信息系统的实现

本文首先讨论了不同企业建立物流信息系统的前提要求，然后指出了不同企业下构建物流信息系统的基本原则和模式，并提出了在国内的特殊环境下企业构建物流信息系统的几点建议。     

智能车辆流量检测器的设计与实现

本文介绍了利用单片机如何实现智能环形线圈车辆检测器，讨论了此类检测器的软硬件设计要点。给出了相应的接口电路。     

Instrumental values

This paper studies identification of partial differences of nonseparable structural functions. A model is defined which admits structural functions exhibiting a degree of monotonicity with respect to a latent variate. The model identifies partial differences when there are instrumental values of covariates over which the latent variate exhibits a local quantile invariance, and a local order condition holds. The result is useful when covariates exhibit discrete variation, as arises often in practice, and when restricting latent variates and covariates to be statistically independent is unpalatable. The results are illustrated with data from the returns-to-schooling study of Angrist and Krueger [1991. Does compulsory schooling attendance affect schooling and earnings? Quarterly Journal of Economics 106, 979–1014].     

Patenting,intellectual property rights and sectoral outputs in Industrial Revolution Britain, 1780–1851

Patenting rose sharply during the British Industrial Revolution. Utilizing time series methods, we investigate the causal relationships between 16 industries and patented inventions. The results show that increased patenting was essentially a consequence of fast growth in the cotton, iron, and mining sectors, which increased the value of protecting intellectual property. Conversely, protecting intellectual property was not a cause of the Industrial Revolution.     

Estimating a generalized correlation coefficient for a generalized bivariate probit model

In this paper we consider semiparametric estimation of a generalized correlation coefficient in a generalized bivariate probit model. The generalized correlation coefficient provides a simple summary statistic measuring the relationship between the two binary decision processes in a general framework. Our semiparametric estimation procedure consists of two steps, combining semiparametric estimators for univariate binary choice models with the method of maximum likelihood for the bivariate probit model with nonparametrically generated regressors. The estimator is shown to be consistent and asymptotically normal. The estimator performs well in our simulation study.     

Identification and estimation of econometric models with group interactions,contextual factors and fixed effects

This paper considers identification and estimation of structural interaction effects in a social interaction model. The model allows unobservables in the group structure, which may be correlated with included regressors. We show that both the endogenous and exogenous interaction effects can be identified if there are sufficient variations in group sizes. We consider the estimation of the model by the conditional maximum likelihood and instrumental variables methods. For the case with large group sizes, the possible identification can be weak in the sense that the estimates converge in distribution at low rates.     

Measuring volatility with the realized range

Realized variance, being the summation of squared intra-day returns, has quickly gained popularity as a measure of daily volatility. Following Parkinson [1980. The extreme value method for estimating the variance of the rate of return. Journal of Business 53, 61–65] we replace each squared intra-day return by the high–low range for that period to create a novel and more efficient estimator called the realized range. In addition, we suggest a bias-correction procedure to account for the effects of microstructure frictions based upon scaling the realized range with the average level of the daily range. Simulation experiments demonstrate that for plausible levels of non-trading and bid–ask bounce the realized range has a lower mean-squared error than the realized variance, including variants thereof that are robust to microstructure noise. Empirical analysis of the S&P500 index-futures and the S&P100 constituents confirms the potential of the realized range.     

Econometric analysis of copyrights

This paper explores the impact of copyrights on firm value and on the demand for firm output. Using panel data on franchise value and ticket sales from the National Football League over the 1991–2000 period, we analyze the effect of copyrights (in this case, team logos) using several parametric estimators, the Arellano and Bond [1991. Some tests of specification for panel data: Monte Carlo evidence and an application to employment equations. Review of Economic Studies 58, 277–297] dynamic panel data estimator, and a semi-non-parametric method based on difference-in-differences propensity score matching. We find a negative effect of logo changes on franchise value that is robust across multiple specifications. In addition, logo changes also appear to have a moderate positive, albeit not particularly robust, impact on ticket sales.     

B2C电子商务物流配送中心选址模型研究

分析了B2C电子商务的发展趋势、发展瓶颈即物流配送成本,为优化物流成本,构建了基于不同路段运输单价不同的最优运输费用的物流配送中心选址模型.     

高校网上招生系统的后续开发与研究

针对目前院校端网上招生录取系统存在的局限性,文章详细介绍了高校网上招生后续开发管理系统的功能,讨论了系统实现中的关键技术及实现方法,指出该系统采用分布式计算技术,建立基于组件的3层C/S模型的体系结构,具有高效性、可伸缩性、开发周期短、安全性高的特点。