Statistical analysis methods are generally derived under the assumption that forecast errors are strictly random and zero in the mean. If the short-term forecast, used as the background eld in the statistical analysis equation, is in fact biased, so will the resulting analysis be biased. The only way to properly account for bias in a statistical analysis is to do so explicitly, by estimating th...

An ensemble Kalman filter (EnKF) based on the Weather Research and Forecasting (WRF) model is used to generate ensemble analyses and forecasts for the extratropical transition (ET) events associated with Typhoons Tokage (2004) and Nabi (2005). Ensemble sensitivity analysis is then used to evaluate the relationship between forecast errors and initial condition errors at the onset of transition, ...

In a non-stationary world subject to structural breaks, where model and mechanism differ, equilibrium-correction models are a risky device from which to forecast. Equilibrium shifts entail systematic forecast failure, and indeed forecasts will tend to move in the opposite direction to the data. A new explanation for the empirical success of second differencing is proposed. We consider model tra...

A rapidly growing literature emphasizes the importance of evaluating the forecast accuracy of empirical models on the basis of density (as opposed to point) forecasting performance. We propose a test statistic for the null hypothesis that two competing models have equal density forecast accuracy. Monte Carlo simulations suggest that the test, which has a known limiting distribution, displays sa...

This paper describes a theoretical study of forecast errors. First, we formally define forecast errors with different rationales, derive several relationships among them, and prove a heuristic formula proposed by Mark Sower.1 Then we study the effects of a systematic bias on the forecast errors. Finally, we extend our study to the situations where correlations across product demands and time ef...

During legacy application to Enterprise Modernization, where the Web logs are not available and deriving Transaction slicing for the ‘n’ number of applications to forecast the Performance is extremely difficult. This involves proper well defined process flows to derive the characteristics of heterogeneous applications. The performance forecast devised has to be approved and stamped by key stake...

This paper proposes a generalized on-line risk-reward model, by introducing the notion of the probabilistic forecast. Using this model, we investigate the on-line rental problem. We design the risk rental algorithms under the basic probability forecast and the geometric distribution probability forecast, respectively. In contrast to the existing competitive analyses of the on-line rental proble...

In this paper, we showed how to quantify the quality of IT forecasts based on Boehm’s cone of uncertainty and DeMarco’s Estimating Quality Factor. With these, we support decision making by providing critical information on IT forecasting quality to IT governors. We illustrated that plotting forecast to actual ratios against a predefined referential conical shape reveals potential biases, for in...

Abnormal uterine periand postmenopausal bleeding represent more than two thirds of the Gynecological consultations and the primary exclusion target off such presentations would be endometrial cancer.(1)Endometrial cancer is the most common malignancy of the female genital tract in the world and the seventh most common cause of death from cancer in women in western Europe.(2)The disease thus mot...