当前位置:首页 >> 其它课程 >> Time Series Analysis

Time Series Analysis


http://www.chinaacc.com/

Time Series Analysis
ACCA P3 考试:Time Series Analysis 1. Uses The use of time series models is twofold: To obtain an understanding of the underlying forces and structure that produced the observed data point; To fit a model and proceed to forecasting, monitoring or even feedback and feed-forward control. Time series analysis is used for many applications, such as: Economic forecasting; Sales forecasting; Budgetary analysis; 2. Components Most time series patterns can be described in terms of two basic components: trend and seasonal variation (“seasonality”). Trend describes a direction of change in the data that tends to occur at a similar rate over the short run. Within a long-term trend, data may change at varying rates or even reverse direction for short periods before continuing at the trend rate. After introducing a new product, for example, a firm may see sales grow slowly, followed by exponential growth as the new product catches on. Seasonality describes calendar-related effects such as sales preceding certain holidays, air miles flown during vacation seasons, etc. Cyclicality is another component. It arises when data plots in a repeating pattern around the trend line over a period lasting more than one year (e.g. economic expansion and contraction) . Business cycles are notoriously difficult to forecast, so they are often combined with trend effects into “trend-cycle” analysis. Trend and seasonality components may coexist in real-life data. For example, sales of a company can grow over years but still follow consistent seasonal patterns (e.g. 25% of sales each year are made in December and only 4% in August). In many cases it is necessary to establish a trend for a series and then adjust each new data point for seasonality. This may be done monthly, quarterly or semi-annually (depending on the review period over which management will compare actual results to forecast). Various methods exist for removing seasonal and cyclical noise from data and to make forecasts: Random walk: Next period's prediction is based on the latest actual. Because the data move up and down due to non-trend factors, however, this method may place too much emphasis on the latest actual result. Simple moving average: Next period's prediction is based on the latest moving average of n values for the series. Stock market analysis; Process and quality control; Inventory studies and workload projections.

中华会计网校 会计人的网上家园 www.chinaacc.com

1

http://www.chinaacc.com/

Weighted moving average:* Weights are assigned to observations, such that more recent results may be given more weight than older results. This still suffers from other problems with the simple moving average method, but can be another improvement over the random walk. It may be better to select equal weights for highly variable series. Exponential smoothing: Weights are assigned to last period's actual result using the “smoothing constant” and to last period's forecast amount (1 minus the smoothing constant) . Because the forecast value for the current period is the weighted actual value plus weighted forecast value of the prior period, this method implicitly gives weight to all actual values in determining the next period forecast.

中华会计网校 会计人的网上家园 www.chinaacc.com

2


赞助商链接
更多相关文档:

Time Series Analysis with Applications in R

Time Series Analysis with Applications in R_计算机软件及应用_IT/计算机_专业资料。Time Series Analysis with Applications in R Jonathan D. Cryer ? Kung-...

Time series analysis时间序列统计方法

CHAPTER 15 Time Series Analysis page 651 15. Introduction page 651 Chapter 15 deals with the basic components of time series, time series decomposition,...

...Prize_using_Time_Series_Analysis_with_R

Short_Term_forecasting_Stock_Prize_using_Time_Series_Analysis_with_R_计算机软件及应用_IT/计算机_专业资料。Short Term forecasting Stock Prize using Time ...

Chapter 4 Time Series Analysis

Chapter 4 Time Series Analysis Time Series (时间序列) Computing (计算) Analysis (分析) 4.1 Time Series 4.1.1 concept A time series is a set of ...

...r语言时间序列分析英文报告Time series regression analysis ...

【原创】r语言时间序列分析英文报告Time series regression analysis report附代码数据_计算机软件及应用_IT/计算机_专业资料。Time series regression analysis report ...

性能测试进阶指南:Loadrunner实战9.1_第5章 数据收集分析

图 5.34 Network Segment Delay Time 5.3.7 Resources(资源监控 资源监控) 资源监控 资源包括很多种,在 Analysis 中监控的都是各种系统的计数器,这些计数器反映...

本学科专业硕士研究生在学期间应重点阅读的主要经典著...

5、Econometric Analysis of Cross Section and Panel Data, J. Wooldridge, 2002. 6、Applied Econometric Time Series, 2nd Edition, by Walter Enders.《应用...

Symbolic Time Series Analysi1_图文

Symbolic Time Series Analysi1_法律资料_人文社科_专业资料。Symbolic Time Series Analysis 符号时间序列 Symbolic dynamics provides a useful tool for modeling and...

改进的消除波动趋势分析法1

Shenyang:Northeastern University Press,2001:334.(in Chinese) [2] Holger Kantz,Thomas Schreiber.Nonlinear time series analysis:second edition[M],Cambridge ...

五、时间构造分析(Time Structuring Analysis)

五、时间构造分析(Time Structuring Analysis)_教育学/心理学_人文社科_专业资料。五、时间构造分析(Time Structuring Analysis) TA 理论认为人们进行沟通的一个重要...

更多相关标签:
网站地图

文档资料共享网 nexoncn.com copyright ©right 2010-2020。
文档资料共享网内容来自网络,如有侵犯请联系客服。email:zhit325@126.com