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Publicações

2015

A MULTI-AGENT BROKERAGE PLATFORM FOR MEDIA CONTENT RECOMMENDATION

Autores
Veloso, B; Malheiro, B; Burguillo, JC;

Publicação
INTERNATIONAL JOURNAL OF APPLIED MATHEMATICS AND COMPUTER SCIENCE

Abstract
Near real time media content personalisation is nowadays a major challenge involving media content sources, distributors and viewers. This paper describes an approach to seamless recommendation, negotiation and transaction of personalised media content. It adopts an integrated view of the problem by proposing, on the business-to-business (B2B) side, a brokerage platform to negotiate the media items on behalf of the media content distributors and sources, providing viewers, on the business-to-consumer (B2C) side, with a personalised electronic programme guide (EPG) containing the set of recommended items after negotiation. In this setup, when a viewer connects, the distributor looks up and invites sources to negotiate the contents of the viewer personal EPG. The proposed multi-agent brokerage platform is structured in four layers, modelling the registration, service agreement, partner lookup, invitation as well as item recommendation, negotiation and transaction stages of the B2B processes. The recommendation service is a rule-based switch hybrid filter, including six collaborative and two content-based filters. The rule-based system selects, at runtime, the filter(s) to apply as well as the final set of recommendations to present. The filter selection is based on the data available, ranging from the history of items watched to the ratings and/or tags assigned to the items by the viewer. Additionally, this module implements (i) a novel item stereotype to represent newly arrived items, (ii) a standard user stereotype for new users, (iii) a novel passive user tag cloud stereotype for socially passive users, and (iv) a new content-based filter named the collinearity and proximity similarity (CPS). At the end of the paper, we present off-line results and a case study describing how the recommendation service works. The proposed system provides, to our knowledge, an excellent holistic solution to the problem of recommending multimedia contents.

2015

Screen reflections impact on HDR video tone mapping for mobile devices: an evaluation study

Autores
Melo, M; Bessa, M; Barbosa, L; Debattista, K; Chalmers, A;

Publicação
EURASIP JOURNAL ON IMAGE AND VIDEO PROCESSING

Abstract
This paper presents an evaluation of high-dynamic-range (HDR) video tone mapping on a small screen device (SSD) under reflections. Reflections are common on mobile devices as these devices are predominantly used on the go. With this evaluation, we study the impact of reflections on the screen and how different HDR video tone mapping operators (TMOs) perform under reflective conditions as well as understand if there is a need to develop a new or hybrid TMO that can deal with reflections better. Two well-known HDR video TMOs were evaluated in order to test their performance with and without on-screen reflections. Ninety participants were asked to rank the TMOs for a number of tone-mapped HDR video sequences on an SSD against a reference HDR display. The results show that the greater the area exposed to reflections, the larger the negative impact on a TMO's perceptual accuracy. The results also show that under observed conditions, when reflections are present, the hybrid TMOs do not perform better than the standard TMOs.

2015

Architecture for centralizing healthcare services

Autores
Ferreira, D; Rocha, T; Brito, AC;

Publicação
2015 10th Iberian Conference on Information Systems and Technologies, CISTI 2015

Abstract
Despite the technological advances, healthcare systems still face several issues. One of the most important is the lack of communication between systems or the communication process speed. If the information about a patient is not promptly shared in time between services, it may jeopardise the practicioner-pacient relationship. In a worse scenario, the system can even become a handicap and turn the Healthcare processes down into a state of total uselessness. A lot has been done in Portugal to enable the interconnection of external healthcare applications with the ones used in the National Health Service. In this article we present an architecture to facilitate this interconnection. Based on a REST architecture and HL7 communication standards, it connects two current solutions, one for melanoma and one for blood donors, with a central healthcare data repository of the National Healthcare Service. © 2015 AISTI.

2015

Preface

Autores
Rocha, A; Correia, AM; Costanzo, S; Reis, LP;

Publicação
Advances in Intelligent Systems and Computing

Abstract

2015

Control and Stability Analysis of Interfaced Converter in Distributed Generation Technology

Autores
Pouresmaeil, E; Mehrasa, M; Shokridehaki, MA; Rodrigues, EMG; Catalao, JPS;

Publicação
IEEE EUROCON 2015 - INTERNATIONAL CONFERENCE ON COMPUTER AS A TOOL (EUROCON)

Abstract
This paper proposes a control technique of an interfaced converter for the integration of Distributed Generation (DG) sources into the power grid. The proposed control technique provides compensation for the active, reactive, and harmonic current components of grid-connected loads. Proper switching functions of the interfaced converter have been defined based on passivity control theory by achieving space equations and suitable series damping injection. Comprehensive simulation results under steady-state and dynamic operating conditions are provided. The effectiveness of the proposed control technique is demonstrated and validated by injecting the maximum available power from DG sources to the power grid, correcting power factor (PF) between grid current and load voltage, generating a fixed voltage at the point of common coupling (PCC) and reducing total harmonic distortion (THD) of grid current.

2015

A communication channels dynamic switching model for always-connected availability of service oriented mobile applications

Autores
Azevedo, D; Paredes, H; Fonseca, B;

Publicação
2015 9TH INTERNATIONAL CONFERENCE ON NEXT GENERATION MOBILE APPLICATIONS, SERVICES AND TECHNOLOGIES (NGMAST 2015)

Abstract
In the current technological landscape, companies face problems associated with the development of mobile applications and rapid integration with their enterprise systems to ensure the availability of value-added services for its customers in pervasive environment. To fill this gap, a generic model for dynamic switching of communication channels to ensure the principles of transparency in distributed environments is proposed, by: (1) designing an interchangeable communication layer for mobile applications; (2) ensuring the transparency of the communication channels; (3) proposing a framework for the development of mobile applications in distributed environment to guarantee the mentioned above communication transparency.

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