Abstract
The presence or absence of long-range correlations in the environmental radioactivity fluctuations has recently attracted considerable interest. Among a multiplicity of practically relevant applications, identifying and disentangling the environmental factors controlling the variable concentrations of the radioactive noble gas radon is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we present a critical re-assessment of a multiplicity of complementary methods that have been previously applied for evaluating the presence of long-range correlations and fractal scaling in environmental radon variations with a particular focus on the specific properties of the underlying time series. As an illustrative case study, we subsequently re-analyze two high-frequency records of indoor radon concentrations from Coimbra, Portugal, each of which spans several weeks of continuous measurements at a high temporal resolution of five minutes.Our results reveal that at the study site, radon concentrations exhibit complex multi-scale dynamics with qualitatively different properties at different time-scales: (i) essentially white noise in the high-frequency part (up to time-scales of about one hour), (ii) spurious indications of a non-stationary, apparently long-range correlated process (at time scales between some hours and one day) arising from marked periodic components, and (iii) low-frequency variability indicating a true long-range dependent process. In the presence of such multi-scale variability, common estimators of long-range memory in time series are prone to fail if applied to the raw data without previous separation of time-scales with qualitatively different dynamics.

Abstract
The pursuit of unhealthy behaviors, such as smoking or binge drinking, not only carries various downside risks, but also provides pleasure. A parsimonious model, used in the literature to explain the decision to pursue an unhealthy activity, represents that decision as a tradeoff between risks and benefits. We build on this literature by surveying a rural population in South Africa to elicit the perceived riskiness and the perceived pleasure for various risky activities and to examine how these perceptions relate to the pursuit of four specific unhealthy behaviors: frequent smoking, problem drinking, seatbelt nonuse, and risky sex. We show that perceived pleasure is a significant predictor for three of the behaviors and that perceived riskiness is a significant predictor for two of them. We also show that the correlation between the riskiness rating and behavior is significantly different from the correlation between the pleasure rating and behavior for three of the four behaviors. Finally, we show that the effect of pleasure is significantly greater than the effect of riskiness in determining drinking and risky sex, while the effects of pleasure and riskiness are not different from each other in determining smoking and seatbelt nonuse. We discuss how our findings can be used to inform the design of health promotion strategies.

Abstract
Serious Games is a field of research that has evolved substantially with valuable contributions to many application domains and areas. Patients often consider traditional rehabilitation approaches to be repetitive and boring, making it difficult for them to maintain their ongoing interest and to assure the completion of the treatment program. This paper reviews Serious Games and the natural and multimodal user interfaces for the health rehabilitation domain. Specifically, it details a framework for the development of Serious Games that integrates a rich set of features that can be used to improve the designed games with direct benefits to the rehabilitation process. Highlighted features include natural and multimodal interaction, social skills (collaboration and competitiveness) and progress monitoring. Due to the rich set of features supported by the framework, the games' rehabilitation efficacy can be enhanced primarily from an increase in the patient's motivation when exercising the rehabilitation tasks.

Abstract
During the last few years many initiatives were taken away in response to high levels of energy consumption verified in data centers. We all know that this is a critical issue nowadays. Many studies carried out raised a lot of concerns about the energy demands of data centers, discussing solutions to reduce it effectively without affecting their day-by-day operation. In this work we made a small contribution to help that. We studied in a data warehousing system how could be possible to establish an energy consumption plan for a star-query. With these plans, we can establish in each phase of a star-query execution the energy consumed by all the elementary tasks that were executed to satisfy it. With this purpose in mind, and motivated by the usual methods and heuristics used on query execution optimization, we designed and developed a method to estimate the energy consumption of each element (operator) integrated in the execution plan of a query at compile time. With it, we also build up the corresponding energy consumption used on executing the star-query, taking into consideration the characteristics of the computational platforms used for.

Abstract
Since the demographics of population, with respect to age, are continuously changing, politicians and scientists start to pay more attention to the needs of senior individuals. Additionally, the well-being and needs of disabled individuals are also becoming highly valued in the political and entrepreneurial society. Intelligent wheelchairs are adapted electric wheelchairs with environmental perception, semi-autonomous behaviour and flexible human-machine-interaction. This paper presents the specification and development of a user-friendly multimodal interface, as a component of the IntellWheels Platform project. The developed prototype combines several input modules, allowing the control of the wheelchair through flexible user defined input sequences of distinct types (speech, facial expressions, head movements and joystick). To validate the effectiveness of the prototype, two experiments were performed with a number of individuals who tested the system firstly by driving a simulated wheelchair in a virtual environment. The second experiment was performed using the real IntellWheels wheelchair prototype. The results achieved proved that the multimodal interface may be successfully used by people, due to the interaction flexibility it provides.

Abstract
An autonomous DGPS navigation system must use an accurate three-dimensional (3D) digital map. However, it is crucial to validate it using data collected in the field. One possible way to validate the map is to employ a vehicle driven by an expert to ensure that the trajectory is plotted within the boundaries of navigation paths. It is essential to take this care, especially when the terrain is very highly uneven and small differences in position may correspond to large vertical deviations. A small navigation error can result in a serious fall, which may damage or even destroy the vehicle. In the Douro Demarcated Region, in northern Portugal, the vineyard is planted on narrow terraces built on steep hills along the winding Douro River. This paper presents the results of a dynamic trajectory survey obtained from a real navigation procedure, carried out by an expert driving an instrumented tractor during the spraying of the vineyard. The results were obtained using a DGPS (accuracy = 2 cm) and compared to an existing Digital Elevation Model (DEM) of the vineyard already created by the authors' work group, with an average accuracy of 10 cm. The results are shown in a C# developed interface with OpenGL facilities, which enable the viewing of the 3D vineyard details. The results confirm the validation of the methodology previously adopted for map extraction and respective equipment selection. The trajectory of the tractor, including some maneuvers, is drawn within the inner and outer edges of each terrace or path that exists in the vineyard. The interface can also be used as an important tool in path planning to automatically extract the topology of the vineyard and to select the best path to carry out some vineyard tasks.