Paulo J. Santos

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This paper describes an algorithm to detect user's mental chunks by analysis of pause lengths in goal-directed human-computer interaction. Identifying and characterizing users' chunks can help in gauging the users' level of expertise. The algorithm described in this paper works with information collected by an automatic logging mechanism. Therefore, it is(More)
The purpose of the present study was to analyze longitudinal changes in 3,000 m running performance and the relationship with selected physiological parameters. Eighteen well-trained male middle-distance runners were measured six times (x3 per year) throughout two consecutive competitive seasons. The following parameters were measured on each occasion:(More)
This paper presents a simple but very powerful technique to support user interface evaluation along with a prototype open environment — I-Observe, the Interface OBServation, Evaluation, Recording, and Visualization Environment — which supports a preliminary implementation of this technique. This technique operates by recording user interface sessions in(More)
The algorithms for short-term load forecast (STLF), especially within the next-hour horizon, belong to a group of methodologies that aim to render more effective the actions of planning, operating and controlling electric energy systems (EES). In the context of the progressive liberalisation of the electricity sector, unbundling of the previous monopolistic(More)
Designers of interactive systems often work in environments that am continuously changing. External, uncontrollable change is rapidly becoming a daily impedim~t in many designers' lives. In this age of rapid technologml progression and heightened competition, systems designers must be able to prepare for, cope with, and even pdbrm better because of(More)
The presence of an electrical de-regulated market reinforces the need of forecast. Actions like network management, load dispatch and network reconfiguration under quality of service constraints, require reliable load forecasts. This paper establishes a methodological approach based on a Gaussian Process Model in order to choose an efficient endogenous(More)
Mobile devices are changing our everyday lives due to development in equipment and software that operates them. The web targeted for these devices must also follow this trend by following a set of best practices. The aim of this paper is to present the state of the art on the mobile Web and show what is more significant in the evaluation of sites for mobile(More)