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Publications

2014

INTERROGATION AND MULTIPLEXING SYSTEM FOR FIBER LOOP MIRROR COUPLED INTENSITY SENSORS USING OTDR

Authors
Rocco Giraldi, MTMR; Fernandes, CS; Ferreira, MS; de Sousa, MJ; Jorge, P; Costa, JCWA; Santos, JL; Frazao, O;

Publication
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS

Abstract
In this article, it is proposed an interrogation and multiplexing system based on optical time domain reflectometer for fiber loop mirror coupled intensity sensors. Pulse width of approximately 100 ns enabled to attain a dynamic range of approximately 18 dB. Good linearity was achieved with a -13.3 dB/mm slope. The resolution of the sensing head was 0.027 mm. The proposed interrogation system showed to be an alternative technique for multiplexing and remote sensing. (C) 2014 Wiley Periodicals, Inc.

2014

Control Strategy for the Stable Operation of Multilevel Converter Topologies in DG Technology

Authors
Pouresmaeil, E; Mehrasa, M; Catalao, JPS;

Publication
2014 POWER SYSTEMS COMPUTATION CONFERENCE (PSCC)

Abstract
A control technique of multilevel converter topologies based on Direct Lyapunov Control method is presented in this paper for integration of Distributed Generation (DG) resources into the power grid. The compensation of instantaneous variations in the reference current components in ac-side and dc-voltage variations of cascaded capacitors in dc-side of the interfacing system are considered properly, which is the main contribution and novelty of this work in comparison with other control strategies. The proposed control technique provides the continuous injection of active power in fundamental frequency from DG sources to the grid. In addition, reactive power and harmonic current components of loads are provided with a fast dynamic response; thereby, achieving sinusoidal grid currents in phase with load voltages, while the required power from load side is more than the maximum capacity of interfaced converter, is possible. Simulation results confirm the effectiveness of the proposed control strategy in DG technology during dynamic and steady-state operating conditions.

2014

MusE Central: A Data Aggregation System for Music Events

Authors
Simoes, D; Abreu, PH; Silva, DC;

Publication
NEW PERSPECTIVES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 2

Abstract
Along with the evolution of the Internet and its ever-increasing use, a significant trend to develop solutions to provide information is noticeable. This scenario increases information decentralization in certain contexts. Nowadays, information regarding music is available online in several online locations. In this context, this paper reports on the development of a web platform that centralizes existing information regarding events, retrieving other contextually related data available. Validated with both information retrieval quality and interface usability metrics, this project attained a more effective and complete concert search service according to the data provided to the user. It has revealed itself capable of retrieving information on more events, when compared to other platforms without a data centralization approach. According to the usability survey results attained, such as an 89 SUS scale score, it was proved that the developed service is provided with a simple and intuitive interface as well.

2014

Identification and Classification of Health Queries: Co-Occurrences vs. Domain-Specific Terminologies

Authors
Lopes, CT; Ribeiro, C;

Publication
Int. J. Heal. Inf. Syst. Informatics

Abstract
Identifying the user's intent behind a query is a key challenge in Information Retrieval. This information may be used to contextualize the search and provide better search results to the user. The automatic identification of queries targeting a search for health information allows the implementation of retrieval strategies specifically focused on the health domain. In this paper, two kinds of automatic methods to identify and classify health queries based on domain-specific terminology are proposed. Besides evaluating these methods, we compare them with a method that is based on co-occurrence statistics of query terms with the word "health". Although the best overall result was achieved with a variant of the co-occurrence method, the method based on domain-specific frequencies that generates a continuous output outperformed most of the other methods. Moreover, this method also allows the association of queries to the semantic tree of the Unified Medical Language System and thereafter their classification into appropriate subcategories.

2014

CAOVerif: An open-source deductive verification platform for cryptographic software implementations

Authors
Almeida, JB; Barbosa, M; Filliatre, JC; Pinto, JS; Vieira, B;

Publication
SCIENCE OF COMPUTER PROGRAMMING

Abstract
CAO is a domain-specific imperative language for cryptography, offering a rich mathematical type system and crypto-oriented language constructions. We describe the design and implementation of a deductive verification platform for CAO and demonstrate that the development time of such a complex verification tool could be greatly reduced by building on the Jessie plug-in included in the Frama-C framework. We discuss the interesting challenges raised by the domain-specific characteristics of CAO, and describe how we tackle these problems in our design. We base our presentation on real-world examples of CAO code, extracted from the open-source code of the NaCl cryptographic library, and illustrate how various cryptography-relevant security properties can be verified.

2014

Using the implicit association test for interface-based evaluations

Authors
Devezas, T; Giesteira, B;

Publication
ACHI 2014 - 7th International Conference on Advances in Computer-Human Interactions

Abstract
Non-instrumental dimensions, the aspects of a product that go beyond its ability to help achieve goals efficiently, are increasingly important in User Experience (UX) research. These dimensions, which include qualities like aesthetics and symbolism, are mainly assessed by self-reports, research has shown. However, respondents can provide wrong answers, willingly, due to concerns like social desirability and self-presentation, or unwillingly, due to the inability to access their inner states. We explored if one implicit measuring method, the Implicit Association Test (IAT), can be used to complement or replace self-report measures. Participants completed six IATs and explicit measures to determine their attitudes toward products represented by pictures of their interfaces. Two non-instrumental dimensions were assessed: valence and self-identification. Overall, implicit and explicit measures displayed a medium correlation. When comparing the correlations between the IATs for the two assessed dimensions and the corresponding explicit measures, similar strong effects were found. This suggests that the IAT bears further exploration as a complement or alternative to selfreport methods. Copyright © IARIA, 2014.

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