卫星通信地球站终端技术的发展

本文介绍了卫星通信地球站终端技术的发展过程,初步论述了新技术应用的环境,为今后研制卫星通信设备提供某些参考。     

Combining information for prediction in linear regression

This article deals with the prediction problem in linear regression where the measurements are obtained using k different devices or collected from k different independent sources. For the case of k=2, a Graybill-Deal type combined estimtor for the regression parameters is shown to dominate the individual least squares estimators under the covariance criterion. Two predictors ŷ _c and ŷ _p are proposed. ŷ _c is based on a combined estimator of the regression coefficient vector, and ŷ _p is obtained by combining the individual predictors from different models. Prediction mean square errors of both predictors are derived. It is shown that the predictor ŷ _p is better than the individual predictors for k≥2 and the predictor ŷ _c is better than the individual predictors for k=2. Numerical comparison between ŷ _c and ŷ _p shows that the former is superior to the latter for the case k=2.     

Forecasting residential burglary

Following the work of Dhiri et al. [Modelling and predicting property crime trends. Home Office Research Study 198 (1999). London: HMSO] at the Home Office predicting recorded burglary and theft for England and Wales to the year 2001, econometric and time series models were constructed for predicting recorded residential burglary to the same date. A comparison between the Home Office econometric predictions and the less alarming econometric predictions made in this paper identified the differences as stemming from the particular set of variables used in the models. However, the Home Office and one of our econometric models adopted an error correction form which appeared to be the main reason why these models predicted increases in burglary. To identify the role of error correction in these models, time series models were built for the purpose of comparison, all of which predicted substantially lower numbers of residential burglaries. The years 1998–2001 appeared to offer an opportunity to test the utility of error correction models in the analysis of criminal behaviour. Subsequent to the forecasting exercise carried out in 1999, recorded outcomes have materialised, which point to the superiority of time series models compared to error correction models for the short-run forecasting of property crime. This result calls into question the concept of a long-run equilibrium relationship for crime.     

Analysis of cointegrated VARMA processes

VARMA (vector autoregressive moving average) processes are proposed for modelling cointegrated variables. For this purpose the echelon form is combined with the error correction form. Procedures for estimating the Kronecker indices which characterize the echelon form and for specifying the cointegration rank are discussed. The asymptotic distribution of the coefficient estimators is given. An example based o n US macroeconomic data illustrates the procedure and demonstrates its feasibility in practice.     

信息的编码、抽象与会计准则——会计准则的信息空间理论诠释

本文从信息空间理论的角度出发,对会计准则的性质进行探讨。在回顾并评价传统解释的基础上,试图得出会计准则“是什么”的一个全新诠释:就静态角度看,会计准则是一种关于企业财务信息编码和抽象的规范体系,其产生根源在于为经济交易的各方提供信息交流和标准化信息转换的平台;就动态角度看,会计准则的变迁则是体系内微观经济个体基于信号发送需要而推动的内涵性变迁和跨体系交易所要求的信息环境共享推动的外延性变迁的共同结果。此外,本文还从会计准则外延性变迁的角度解析了当前各国会计准则存在重大差异的现象。     

谈谈编辑的职业道德

市场经济条件下，人们的思想、观念发生了深刻的变化，以权谋私，权钱交易，渗透到各行各业，如何进行行业自律，如何规范自己的道德行为，近在眉睫。做为从事新闻出版宣传工作的编辑在职业道德建设方面更应率先垂范，不仅要做传播化的使，更应做奠定职业道德的模范。     

EPC技术在服装行业的应用研究

随着无限射频技术（RFID）在物体标识方面应用的成熟,人们提出了一个基于互联网的全球物联网,即EPC网络,旨在对每一件出厂的产品做到唯一识别,以便跟踪它的整个生命周期.本文分析了服装行业供应链的特点和信息化的需求,在此基础上研究了EPC在服装行业的应用,并对其未来的发展进行了展望.     

Important Intermediate Transactions and Multi-sectoral Modelling

For the maintenance and development of a disaggregated econometric model, the present paper deals with some aspects related to the identification of important intermediate transactions. First, some methodological aspects related to earlier works are discussed. By comparing the properties of different selection methods based on the recent West German input–output table, the calculations confirm the common finding that the necessary level of endogenization can be bounded meaningfully by an a priori investiga tion of the intersectoral transactions. This is also valid if the selection method considers restrictions that deal with the consistence of input–output tables and if some broader error criteria are applied. The main result of the empirical applications seems to be that some attention should be paid to temporal changes of important coefficients.     

容积式流量计有级容差调整在二维坐标系内的认识

以二维坐标系的方式，直观地分析了容差调整过程中流量计误差曲线坐标变化的情况，进而说明了有级容差调整的实质，并结合各专业厂家生产技术的实际情况，说明了调整齿轮选择表的正确使用。     

天然气压缩因子对流量计量的影响

探讨了速度式和容积式流量计用于天然气计量时,天然气压缩因子对其计量结果的影响;同时也探讨了无压缩因子修正或修正不当而造成的二次仪表计量误差.