BACKGROUND Influenza viruses cause seasonal outbreaks in temperate climates, usually during winter and early spring, and are endemic in tropical climates. The severity and length of influenza outbreaks vary from year to year. Quick and reliable detection of the start of an outbreak is needed to promote public health measures. METHODS We propose the use of an exponentially weighted moving aver...

BACKGROUND As gait speed and transfer times are considered to be an important measure of functional ability in older adults, several systems are currently being researched to measure this parameter in the home environment of older adults. The data resulting from these systems, however, still needs to be reviewed by healthcare workers which is a time-consuming process. METHODS This paper prese...

A traditional approach to monitor both the location and the scale parameters of a quality characteristic is to use two separate control charts. These schemes have some difficulties in concurrent tracking and interpretation. To overcome these difficulties, some researchers have proposed schemes consisting only one chart. However, none of these schemes is designed to work with individual observat...

This paper examines the ability of several models to generate optimal hedge ratios. Statistical models employed include univariate and multivariate GARCH models, and exponentially weighted and simple moving averages. The variances of the hedged portfolios derived using these hedge ratios are compared with those based on market expectations implied by the prices of traded options. One-month and ...

In this paper, the Shiryaev-Roberts (SR) procedure is examined and compared with the change point CUSUM (CPC) procedure for monitoring the dispersion of a normal process. It will be shown that the SR chart performs better than the CPC chart for the pre-specified dispersion shift. In practice, when the magnitude of a future dispersion shift is unknown, it is always desired to design a control ch...

Many extensions and modifications have been made to standard process monitoring methods such as the exponentially weighted moving average (EWMA) chart cumulative sum (CUSUM) chart. In addition, new schemes proposed based on alternative weighting of past data, usually put greater emphasis data less weight current recent data. other cases, output one method, EWMA statistic, is used input another ...

Control charts are graphical tools widely used to monitor manufacturing processes to quickly detect any change in a process that may result in a change in product quality. The statistic plotted on a control chart is based on samples of n ≥ 1 observations (rational subgroups) that may be taken at regular sampling intervals. However, there are numerous practical applications using individual obse...