An interesting aspect of games is the relative extent to which a player can positively influence his results by making appropriate strategic choices. This question is closely related to the issue of how to distinguish between games of skill and games of chance. The distinction between these two types of games is definitely interesting from a juridical point of view. Borm and Van der Genugten (2...

Many accuracy measures have been proposed in the past for time series forecasting comparisons. However, many of these measures suffer from one or more issues such as poor resistance to outliers and scale dependence. In this paper, while summarising commonly used accuracy measures, a special review is made on the symmetric mean absolute percentage error. Moreover, a new accuracy measure called t...

Surveys show that the mean absolute percentage error (MAPE) is the most widely used measure of forecast accuracy in businesses and organizations. It is however, biased: When used to select among competing prediction methods it systematically selects those whose predictions are too low. This is not widely discussed and so is not generally known among practitioners. We explain why this happens. W...

A two-step white-light spectral interferometric technique to measure the relative phase change on reflection from a thin-film structure is presented. The technique is based on recording of the channelled spectra at the output of a Michelson interferometer and their processing by using a windowed Fourier transform to retrieve the phase functions. In the first step, the phase difference between t...

A measure of location relative efficiency for location of a single sample. The question o f how much to trim or which weighting constant to use are practical considerations in applying robust methods such as trimmed means (L-estimators) and Huber statistics (M-estimators). An index o f location relative effi­ ciency (LRE), which is a ratio of the narrowness o f resulting confidence intervals, w...

The problem of developing a detoxified Flexner dysentery antigen for use in the armed forces during the recent war (Barnes, Dewey, Henry, and Lupfer, 1947; Barnes and Dewey, 1947) required a test by which the results of a given chemical or physical manipulation of the antigen could be evaluated with respect to both toxicity and protection. It was necessary to do this with such precision and def...

Online encyclopedia Wikipedia is one of the most popular sources of knowledge. It is often criticized for poor information quality. Articles can be created and edited even by anonymous users independently in almost 300 languages. Therefore, a difference in the information quality in various language versions on the same topic is observed. The Wikipedia community has created a system for assessi...

PURPOSE Persons with visual impairments or blindness can face significant restrictions to their efficient travel, especially when attempting transit transfers and using a large, multi-modal terminal. Little is known about what makes some tasks much harder than others. This paper presents an approach to empirically measure the difficulty of a variety of transit tasks. METHOD An experiment was ...