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
Pereira M.,New University of Lisbon |
Ramalhete F.,Autonomous University of Lisbon
Finisterra | Year: 2017
The uneven nature of the (re)production and (re) appropriation of territories, through differential access to territorial resources, induces conflicts between public and private actors. In the Welfare State, public interventions aim to promote equity in territories and among citizens. However, these objectives are not always protected, for State action hijacked by the influence of dominant groups and the scarcity of resources, fails to privilege the less favoured territories. In the described interventions, spatial (in)justice emerges in situations which compromise equity and cohesion, implicit in the principles of territorial policies. The case study, located in a metropolitan context, shows an illegal occupation area, where urban deficiencies have been perpetuated in spite of the administration's initiatives to overcome them.
Silva I.,Instituto Universitario Of Lisbon |
Alturas B.,Instituto Universitario Of Lisbon |
Carneiro A.,Autonomous University of Lisbon
Iberian Conference on Information Systems and Technologies, CISTI | Year: 2017
Modeling tools serve to guide and discipline the software development process during the design process. However, such tools are not fully explored from a functional point of view, either the complexity of the subject matter or the usability thereof. This study proposes to evaluate the use of three system modeling tools, through a study using students of the Postgraduate Program in Applied Informatics to the Organizations. The objective of the study was to evaluate the usability of three tools that allow system modeling using UML notation. Are presented studies on the levels of acceptance and use of the analyzed tools. Based on the preliminary results of this study, it was observed that the Visio tool has better usability and functionality than the other tools. © 2017 AISTI.
Marques da Silva M.,Autonomous University of Lisbon |
Dinis R.,Telecommunications Institute of Portugal
Physical Communication | Year: 2016
This paper considers the use of massive multiple input, multiple output (MIMO) combined with single-carrier with frequency-domain equalization (SC-FDE) modulations, associated to millimeter wave (mm-Wave) communications using precoding. For the sake of comparison, this paper performs a comparison of pre and post-processing methodology, using the same algorithms. In this paper, we consider three different types of algorithms: Zero Forcing Transmitter (ZFT), Maximum Ratio Transmitter (MRT), and Equal Gain Transmitter (EGT), both of the latter two with iterative detection schemes. The advantage of both MRT and EGT relies on avoiding the computation of pseudo-inverse of matrices. The performance of MRT and EGT are very close to the matched filter bound just after a few iterations of a new proposed interference cancellation, even when the number of receiving antennas is not very high. © 2017 Elsevier B.V.
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.
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 |
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.