SEASONAL ADJUSTMENT BY A BAYESIAN MODELING

Abstract. The basic ideas underlying the construction of a newly introduced seasonal adjustment procedure by a Bayesian modeling are discussed in detail. Particular emphasis is placed on the use of the concept of the likelihood of a Bayesian model for model selection. The performance of the procedure is illustrated by a numerical example.     

A NOTE ON THE COMPUTATION OF THE BAYESIAN DECOMPOSITION OF A TIME SERIES

Abstract. The purpose of the present note is to propose an efficient algorithm for the Bayesian decomposition of a time series, utilizing some results recently developed in the area of methods of regularization of certain integral equations. Within this framework, it is shown how the special structure of the problem can be exploited so that a considerable gain in computational efficiency over existing procedures can be obtained.     

IMPROVING THE COMPUTATIONAL EFFICIENCY OF THE BAYESIAN DECOMPOSITION OF A TIME SERIES: A COMMENT

Abstract. This note describes an improvement of Ishiguro's algorithm for the Bayesian decomposition of a time series based on the use of a specialized band Cholesky factorization.     

A PROTOTYPICAL SEASONAL ADJUSTMENT MODEL

Abstract. The paper analyses unobserved-components modelling and estimation for the simplest ARIMA process that accepts a full decomposition into trend, seasonal and irregular components. This prototypical model exemplifies many features of and issues arising in model-based seasonal adjustment that are less transparent in more complex seasonal time series models. In particular the analysis illuminates the major issues surrounding the specification of the component models and the identification of a unique structure for them. In so doing, the relationship between reduced- and structural-form approaches to unobserved components estimation is illustrated within an ARIMA-modelling framework. Finally, the properties of the minimum mean-squared-error estimators of the unobserved components are examined and the two main types of estimation error, revisions in the preliminary estimator and error in the final estimator, are analysed.     

THE AUTOCORRELATION FUNCTION OF SEASONAL ARMA MODELS

Abstract. This note obtains the theoretical autocorrelation function of an ARMA model with multiplicative seasonality. It is shown that this function can be interpretated as the result of the interaction between the seasonal and regular autocorrelation patterns of the ARMA model. The use of this result makes easier the identification of the structure of the model, is helpful in choosing between a multiplicative or additive seasonal component and leads to a better understanding of the properties of the estimated autocorrelation function of scalar ARMA processes.     

GE水煤浆气化锁斗程序改造

对合成氨厂煤气化开车以来遇到的锁斗运行问题进行论证,通过对其控制程序的改造,保证气化炉的正常排渣。     

涤纶短纤维生产线增容后纺丝工艺的调整

介绍涤纶短纤维直接纺生产线增容前后的纺丝工艺参数 ,分析生产能力由 5 7t/ d扩大到 6 3t/ d后 ,纺丝温度、纺丝速度、冷却条件、组件及过滤器压力等参数的变化及应采取的措施。     

REPARAMETRIZATION ASPECTS OF NUMERICAL BAYESIAN METHODOLOGY FOR AUTOREGRESSIVE MOVING-AVERAGE MODELS

Abstract. Within the context of likelihood and Bayes approaches to inference in autoregressive moving-average (ARMA) time series models, previous ideas on parameter transformation and numerical integration for implementing Bayesian procedures are reviewed. Some novel transformation ideas are introduced and their role in an efficient numerical integration approach is examined. Some comparisons of the effectivesness of different numerical integration strategies are made.     

涤纶短纤维生产线前后纺生产能力的调整方法

介绍了涤纶短纤维生产线前后纺生产能力调整的方法 ,主要述及调整纺丝速度对原丝的影响 ,以及生产能力调整时应注意的几个问题。调整生产能力要根据产品纤度、现有喷丝板的情况来选择适当的纺丝速度 ,也可通过改变喷丝板孔数来实现。其他工艺条件也应做相应调整。实践证明 :调整前后成品的物理指标基本一致。     

浅谈整流机组的均流及其检测与调整

分析了对整流机组均流程度进行检测与调整的必要性。介绍了衡量均流程度的均流系数K及其计算方法,提出了简便易行且安全可靠的快熔元件压降检测调整法。     

电磁耦合调速方式在陶瓷拉坯机上的应用

本文比较了当前陶瓷拉坯机的几种调速方式及各自特点,介绍了基于电磁耦合方式的转速调节原理,给出了相应的控制主电路和控制电路原理框图,分析了该电路工作原理。试验结果表明,基于该调速方式的陶瓷拉坯机具有良好的性能。     

基于ET2008的服装CAD打板中常见问题及调整对策

基于ET2008服装CAD打板系统,对在使用ET2008服装CAD打板过程中的常见问题进行总结,并提出了合理的调整对策。希望能够为服装企业CAD技术应用与推广提供参考。     

大化肥厂产品结构调整和发展的几点建议

从目前化肥施用和下世纪发展的角度,论述单一生产尿尿的大化肥厂适应农业的需要,调整产品结构的形势,提出发展多品种化肥,如控制释放化肥,专用化肥等,以及根据农业需要开展农化服务的建议。     

循环流化床锅炉主要热工参数的控制与调整

系统说明了循环流化床锅炉运行中的几个主要热工参数,并分析了这些参数在运行中调整的主要作用和意义,最后结合本厂实际提出部分参考数据。     

浮法退火窑辊道及冷端输送辊道玻璃跑偏的原因及调整方法

结合国内外30多家浮法玻璃生产线的安装调试经历,阐述了采取正确调整八字辊角度、开槽加胶套装及螺丝紧定胶圈法、分段整体移动横梁法和分区段控制偏差法等技术措施,对预防和调整玻璃带和玻璃板在整个工艺线输送过程中的跑偏是十分有效的.     

A PROCEDURE FOR EVALUATION OF COMMERCIAL FCC CATALYSTS

Based on the correlations between laboratory units and commercial plants, a procedure has been developed to guide commercial FCC (Fluid Catalytic Cracking) catalysts selection. Examining the operability of catalyst mixtures during catalyst transition period is emphasized. The testing procedure is simple and reliable. A commercially available catalyst and the catalyst currently in use have been compared to demonstrate the applicability of this procedure. The commercial testing has confirmed the reliability of laboratory results. The use of the catalyst evaluated led to a 30% saving in catalyst cost.     

A PROCEDURE FOR EVALUATION OF COMMERCIAL FCC CATALYSTS

Based on the correlations between laboratory units and commercial plants, a procedure has been developed to guide commercial FCC (Fluid Catalytic Cracking) catalysts selection. Examining the operability of catalyst mixtures during catalyst transition period is emphasized. The testing procedure is simple and reliable. A commercially available catalyst and the catalyst currently in use have been compared to demonstrate the applicability of this procedure. The commercial testing has confirmed the reliability of laboratory results. The use of the catalyst evaluated led to a 30% saving in catalyst cost.     

对硝基甲苯邻磺酸合成工艺研究

以对硝基甲苯为原料，经三氧化硫磺化合成了对硝基甲苯邻磺酸，研究了影响反应的因素，主产品含量可达９８％以上，收率达９６％。     

大氮肥装置调整原料和产品结构方案探讨

分析大氮肥装置的现状和技术改造的必要性,提出以“煤代油”或“渣油劣质化”为核心内容的原料和产品结构的调整方案,建议尽快实施技术改造并为未来的能源替代进行技术装备。