27,643 research outputs found
Elements for Response Time Statistics in ERP Transaction Systems
We present some measurements and ideas for response time statistics in ERP
systems. It is shown that the response time distribution of a given transaction
in a given system is generically a log-normal distribution or, in some
situations, a sum of two or more log-normal distributions. We present some
arguments for this form of the distribution based on heuristic rules for
response times, and we show data from performance measurements in actual
systems to support the log-normal form. Deviations of the log-normal form can
often be traced back to performance problems in the system. Consequences for
the interpretation of response time data and for service level agreements are
discussed.Comment: revtex, twocolumn, 8 pages, 13 figures. figures replaced by coloured
version
Survey of data mining approaches to user modeling for adaptive hypermedia
The ability of an adaptive hypermedia system to create tailored environments depends mainly on the amount and accuracy of information stored in each user model. Some of the difficulties that user modeling faces are the amount of data available to create user models, the adequacy of the data, the noise within that data, and the necessity of capturing the imprecise nature of human behavior. Data mining and machine learning techniques have the ability to handle large amounts of data and to process uncertainty. These characteristics make these techniques suitable for automatic generation of user models that simulate human decision making. This paper surveys different data mining techniques that can be used to efficiently and accurately capture user behavior. The paper also presents guidelines that show which techniques may be used more efficiently according to the task implemented by the applicatio
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