Maia B.M.,Autonomous University of Lisbon
Dynamical Systems | Year: 2017
The β-transformation of the unit interval is defined by Tβ(x) ≔ βx (mod 1). Its eventually periodic points are a subset of [0, 1] intersected with the field extension (Formula presented.). If β > 1 is an algebraic integer of degree d > 1, then (Formula presented.) is a (Formula presented.)-vector space isomorphic to (Formula presented.); therefore, the intersection of [0, 1] with (Formula presented.) is isomorphic to a domain in (Formula presented.). The transformation from this domain which is conjugate to the β-transformation is called the companion map, given its connection to the companion matrix of β's minimal polynomial. The companion map and the proposed notation provide a natural setting to reformulate a classic result concerning the set of periodic points of the β-transformation for (Formula presented.) numbers. It also allows to visualize orbits in a d-dimensional space. Finally, we refer connections with arithmetic codings and symbolic representations of hyperbolic toral automorphisms. © 2017 Informa UK Limited, trading as Taylor & Francis Group
Sales C.M.D.,Autonomous University of Lisbon |
Evans C.,Nottinghamshire Healthcare NHS Trust
Revista de Psiquiatria Clinica | Year: 2012
Background: The Clinical Outcome Routine Evaluation - Outcome Measure (CORE-OM) is a European self-report measure of psychological well-being in adults, which is already adapted for more than 20 countries. The CORE-OM is applicable in primary care settings, in occupational health and educational contexts, as well as for evaluations of mental health services quality. Objectives: To translate the CORE-OM into and adapt it to the Portuguese language. Methods: The translation of CORE-OM to Portuguese was conducted in accordance with the CORE System Trust international guidelines, in collaboration with the authors of the original CORE-OM. This guidelines involved seven independent translations by individuals familiar/non-familiar with the field of mental health and by licensed translators. After the discussion of these translations in a focus group, a final version of the Portuguese CORE-OM was established. Individuals from different age groups, socio-cultural backgrounds and educational levels participated in this translation process. Results: Preliminary results in a sample of 111 individuals (general population) show that the translated measure is confidential and has a good internal reliability. Discussion: The Portuguese version of the CORE-OM is a valid and adequate instrument to evaluate psychological changes, both in research and clinical practice contexts.
Marques Da Silva M.,Telecommunications Institute of Portugal |
Marques Da Silva M.,Autonomous University of Lisbon |
Dinis R.,Telecommunications Institute of Portugal |
Dinis R.,New University of Lisbon
European Transactions on Telecommunications | Year: 2011
In this paper, we consider iterative frequency-domain receivers for block transmission techniques with rate-1 space-time block coding (STBC) for two or four transmit antennas. Single carrier with frequency-domain equalisation (SC-FDE) combined with antenna diversity is a promising candidate for future broadband wireless systems. Because our STBC with four transmit antennas is not orthogonal, our receiver includes the cancellation of the residual interference, allowing performances close to the ones of an orthogonal code. We propose an iterative STBC receiver that considers an iterative detection and channel estimation. The channel estimates usually obtained with the help of pilot symbols and/or training sequences are multiplexed with data symbols. Because this leads to spectral degradation, the use of superimposed pilots (i.e. pilots added to data) was recently proposed as an efficient alternative. Our performance results show that the proposed SC-FDE STBC receiver allows excellent performance with the use of the channel data obtained from the channel estimation. © 2011 John Wiley & Sons, Ltd.
Von Humboldt S.,ISPA University |
Leal I.,ISPA University |
Laneiro T.,Autonomous University of Lisbon |
Tavares P.,University of Lisbon
Stress and Health | Year: 2013
To date, little research has yet focused in broad assessment for management consultancy professionals. This investigation aims to analyse management consultants' self-perceptions of occupational stress (SPoOS), sources of stress (SoS) and stress management strategies (SMS) and to find latent constructs that can work as major determinants in consultants' conceptualization of SPoOS, SoS and SMS. Measures were completed, including demographics and interviews. Complete data were available for 39 management consultants, 53.8% male and aged between 23 and 56 years (M = 38.0; SD = 9.2). The data were subjected to content analysis. Representation of the associations and latent constructs were analysed by a multiple correspondence analysis. Results indicated that 'intellectual disturber' (31.4%) was the most referred SPoOS, 'high workload' (15.1%) was identified as the most prevalent perceived SoS and 'coaching' (19.0%) was the most mentioned SMS. No significant differences between the two gender groups were found regarding the three total scores. SPoOS was explained by a two-factor model: 'organization-oriented' and 'person-oriented'. A three-dimension model formed by 'job concerns', 'organizational constraints' and 'career expectations' was indicated as a best-fit solution for SoS, and SMS was best explained in a three-dimension model by 'group dynamics strategies', 'organizational culture strategies' and 'individual support strategies'. This research makes a unique contribution for a better understanding of what defines SPoOS, SoS and SMS for management consultants. Copyright © 2013 John Wiley & Sons, Ltd.
Silveira P.E.,Autonomous University of Lisbon |
Silveira P.E.,Lusíada University of Lisbon
Advances in Intelligent Systems and Computing | Year: 2015
Structuring the information and knowledge needed to implement a factory, as well as doing its control and management by computer systems, is the purpose of the meta-model and solutions here presented. This meta-model includes: an object-oriented model to structure the needed information and knowledge; a model for manufacturing systems; a prototype that integrates the two previously referred models with real time control, in order to plan and to realize the management of a factory. A first step of this work has been accomplished at the Ephestia Kuehniella Bio-factory, controlled by computer in the Laboratory of the Biology Department at the University of Azores. In this paper we present a meta-model for a factory planning, controlling and managing, with updated conceptual and technological options, preparing the way for a new industrial implementation of the above mentioned Biofactory. © Springer International Publishing Switzerland 2015.
Silva R.,Autonomous University of Lisbon |
Sa Silva J.,University of Coimbra |
Boavida F.,University of Coimbra
2015 IEEE 10th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, ISSNIP 2015 | Year: 2015
Large urban areas are nowadays covered by millions of wireless devices, including not only cellular equipment carried by their inhabitants, but also several ubiquitous and pervasive platforms used to monitor and/or actuate on a variety of phenomena in the city area. Whereas the former are increasingly powerful devices equipped with advanced processors, large memory capacity, high bandwidth, and several wireless interfaces, the latter are typically resource constrained systems. Despite their differences, both kinds of systems share the same ecosystem, and therefore, it is possible to build symbiotic relationships between them. Our research aims at creating a resource-sharing platform to support such relationships, in the perspective that resource unconstrained devices can assist constrained ones, while the latter can extend the features of the former. Resource sharing between heterogeneous networks in an urban area poses several challenges, not only from a technical point of view, but also from a social perspective. In this paper we present our symbiotic resource-sharing proposal while discussing its impact on networks and citizens. © 2015 IEEE.
Silva R.,Autonomous University of Lisbon |
Silva J.S.,University of Coimbra |
Boavida F.,University of Coimbra
Proceedings of the IEEE International Conference on Industrial Technology | Year: 2015
Mobility support is one of the main requirements in current wireless sensor networks (WSN), as WSN technology becomes mature and its range of applications gets wider. Due to the very nature of WSNs, along with their use in all sorts of Internet of Things (IoT) scenarios, it is frequent that sensor nodes, or even groups of sensor nodes, need to change their wireless point of attachment without losing connectivity. Nevertheless, mobility support in WSNs has not yet been standardized and, therefore, mobility is still looked at as a challenge. This is even more so in critical, industrial scenarios. In this paper we present and evaluate a new infrastructure-based mobility solution for WSNs, named Network of Proxies (NoP), developed for the referred type of scenarios. NoP was deployed and tested in a critical use case, namely for monitoring employees' vital signs status in an oil refinery, with the aim of evaluating its feasibility and performance. The results show that NoP is capable of efficiently handling mobility, outperforming existing solutions and meeting the stringent case-study requirements. © 2015 IEEE.
Lopes P.,Autonomous University of Lisbon
Observatorio | Year: 2015
Do adults in training in Grande Lisboa portray a country of typically low information consumption (Hallin and Mancini, 2004)? The interest in the news remains low (Rebelo et al., 2008)? Among these adults, sending and receiving emails is the most popular online activity (OberCom, 2012)? Do the effects of media exposure (to old and new media) determine media skills and competencies? This paper presents some results of the research project "Media literacy and citizenship. Practices and competencies of adults in training in Grande Lisboa", developed in the Centre for Research and Studies in Sociology (CIES), between 2009 and 2013, carried out under the Doctoral Programme in Sociology from ISCTE-IUL. Some clues: the results show that there is a clear distinction among generations in access to information and that only a minority of the subjects contributes with original content and participates publicly in online environments. Copyright © 2015 (Paula Lopes).
Curto H.S.,Autonomous University of Lisbon |
Dias A.,Autonomous University of Lisbon
International Journal of Public Sector Management | Year: 2014
Purpose-The purpose of this paper is to clarify the relationship between administrative reform in Portugal and the impacts on the dependence of local governments in the face of budgetary resources of state and local municipal revenue collection, which is understood as a form, among others, participation civil society in local public policies. Design/methodology/approach-The study opts for an exploratory analysis using the grounded theory approach, including the use of data relating to local government structures and partnerships with the private sector, based on the main lines of the public administration reform. The data were supplemented by documentary analysis, including legislative documents and papers in specialized area of administrative decentralization and civil society participation in local public policies. Findings-The paper provides empirical insights about how the increased participation of civil society in local public policies is associated with less reliance on state budgets and a greater number of local managerial structures. Research limitations/implications-Due to the chosen research approach, the results cannot be generalized. A comparative study between several countries could bring several interesting insights. Social implications-The paper includes implications for economic and social development of new public policies in the context of administrative reforms. Originality/value-This paper makes several theoretical and empirical contributions on this research field specially about local public manager’s decisions for financial resources transfers within the active policy of sustainable local development. © Emerald Group Publishing Limited.
Monteiro J.,Autonomous University of Lisbon |
Faisca L.,Autonomous University of Lisbon |
Nunes O.,Autonomous University of Lisbon |
Hipolito J.,Autonomous University of Lisbon
Acta Medica Portuguesa | Year: 2010
The objective of the current study was to adapt and validate the Roland Morris disability questionnaire (RMDQ) to the Portuguese patients because there are no European Portuguese psychometric instruments to evaluate patients suffering from low back pain. After translation and back translation the Portuguese version of the RMDQ was tested in 112 patients with low back pain (30 males and 82 females) to analyse psychometric characteristics. Analysis of measures obtained points to high levels of internal consistency (Cronbach's alpha: 0.81) and temporal stability (test-retest: r = 0.86). External validity was assessed by association with numerical pain rating scale (END), Schöber test (TS) and fingertip floor measurement (GFA). The results revealed a large correlation between the RMDQ and END (r = 0.73) and a medium correlation with TS and GFA (in this order, r = -0,52 and r = 0,42). The psychometric analysis showed that the RMDQ gives reliable measures for the disability of patients with back pain and was successfully adapted and validated to the European Portuguese patients. © 2010 CELOM.