Exact moments of the sample autocorrelations from series generated by general arima processes of order (p, d, q), d=0 or 1

Formulae for the numerical computation of the first four exact moments of the sample autocorrelations, given a time series realisation from a general autoregressive moving average process of order (p, d, q) with d=0 or 1, are presented. The exact mean and variance of the sample autocorrelations are computed for various sample sizes and several time series models. The evaluated results are compared with those obtained from approximate formulae for the mean and variance of the sample autocorrelations. A specification of the numerical accuracy of the first two exact moments is included.     

Social services and telecommunications: Innovation in human services delivery

This article presents an analysis of the current state of adoption of telecommunications technologies by organizations and individuals who work in human services. It examines the barriers to use of innovations and suggests the future course of acceptance for the different technologies. Radio and telephone appear to have the fewest barriers to adoption, and it is likely that as consumers become more accustomed to advanced technologies in their homes, they will be more likely to accept them in the workplace.     

用窒息价格辅助定价

本文重点阐述了在假定线性需求是合理的以及窒息价格的相关信息可用的情况下计算均衡价格的公式。它能够让分析人员信服,即使在数据非常有限以及缺乏数学支持的情况下,有效的基准计算也是可以实现的。此外,它还有助于阐明价格弹性与需求变化之间的变化趋势,