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Publications

2012

PLAYER - a European Project and a Game to Foster Entrepreneurship Education for Young People

Authors
Soraci,; Mostert,; Casaramona,; Fonseca,; Paredes,; Duarte,; Lima,; Carvalho,; Varajão,; Morgado,,; Rahe,; Rus,; Martins,; Neves,; Gonçalves,; Nunes,; Sanders,; Bo?njak,; Klein,; Lapajne,; Barracho,; Bojovic,; Bo?njak,; Pereira,;

Publication
JUCS - Journal of Universal Computer Science

Abstract

2012

Suspended-core fibers for sensing applications

Authors
Frazao, O; Silva, RM; Ferreira, MS; Santos, JL; Ribeiro, ABL;

Publication
Photonic Sensors

Abstract
A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring. © The Author(s) 2012.

2012

Filling the gap in quality assessment of video object tracking

Authors
Carvalho, P; Cardoso, JS; Corte Real, L;

Publication
IMAGE AND VISION COMPUTING

Abstract
Current evaluation methods either rely heavily on reference information manually annotated or, by completely avoiding human input, provide only a rough evaluation of the performance of video object tracking algorithms. The main objective of this paper is to present a novel approach to the problem of evaluating video object tracking algorithms. It is proposed the use different types of reference information and the combination of heterogeneous metrics for the purpose of approximating the ideal error. This will enable a significant decrease of the required reference information, thus bridging the gap between metrics with different requirements concerning this type of data. As a result, evaluation frameworks can aggregate the benefits from individual approaches while overcoming their weaknesses, providing a flexible and powerful tool to assess and characterize the behavior of the tracking algorithms.

2012

Geophones on blocks: a prototype towable geophone system for shallow land seismic investigations

Authors
Moura, RM; Senos Matias, MJS;

Publication
GEOPHYSICAL PROSPECTING

Abstract
In recent years some authors have given a certain amount of attention to towed seismic reflection acquisition systems. Based on some of these works we sought to design and test a system making use of currently available geophones instead of specifically designed sensors as employed in some previous works. Thus, bearing in mind that the geophone's characteristics are achieved in the conditions that they are originally designed to be employed in, i.e., coupled with a spike driven into the ground, we devoted our attention to some of the variables involved in the geophone's performance, namely the total weight, the effect of a spikeless geophone and the surfaces on which the geophone is placed. Previously, we had experimentally verified some variations in the signal response due to coupling geophones in different surface materials, such as hard soil, asphalt and concrete pavement and we noticed that these surface materials were in fact an important factor in the overall response. Hence, these materials, or as we also called them coupling agents, could be employed as a base material in the construction of a mobile seismic acquisition device composed of blocks of a certain size, on which the geophone would be then inserted and thus making it into a spikeless surface towable system. Therefore, various materials were tested in order to select one that could maintain a similar fidelity to that of the spike coupled geophone and thus contribute towards building a more time efficient and towable geophone and block system. Pinging tests revealed variations in the coupling frequency and damping characteristics of each coupling agent and from all of these tested materials one was selected for field comparative tests with the normally planted geophones with spike coupling. Finally a seismic reflection profile was acquired simultaneously with both systems, i.e., spike coupling versus cement block coupled geophones.

2012

The effect of prejudiced memory in strategies for social interaction

Authors
Matos, R; Campos, P;

Publication
Proceedings of the IADIS International Conference Intelligent Systems and Agents 2012, ISA 2012, IADIS European Conference on Data Mining 2012, ECDM 2012

Abstract
In human society, the majority of individuals try to achieve objectives that are individual to them, carrying this out, in the majority of cases, in an independent manner. It has in fact been repeat edly verified that some individuals are able to function as catalysts, introducing ideas and technology that go against the ideological currents that govern their social relationships. A variety of factors can be indicated as being partly responsible for this capacity for innovation and social adaptation, one of them being the perpetuation of collective memory by means of written texts, the press, and by all the different new types of media that we have today at our disposal, and which are used by certain individuals in determined contexts to obtain some type of advantage. What effect, however, would pre judice have when a pplied to strategies of interaction in a social network? Prejudice is something that is generally considered to be pejorative. Taking the free circulation of information amongst individuals within a social network as a basic premise, would it be possible to affirm that we would always achieve improved performance of society as a whole when the collective memory is loaded with prejudice? This work attempts to provide an answer to that question, analysing the relationship between the efficiency of a social network and the memories of the individuals who make it up, when the network itself is not immune from information that is (potentially) incorrect.

2012

Sprite-based generation of side information for multi-view Distributed Video Coding

Authors
Ciobanu, L; Corte Real, L;

Publication
MULTIMEDIA TOOLS AND APPLICATIONS

Abstract
Generation of side information for multi-view Distributed Video Coding in multi-camera environments (e.g., video surveillance) poses challenges in scenarios with temporary non-overlapping among views and consequently, no resources for generating the side information at some time instants. In this paper we extend our previous work (Ciobanu and Corte-Real, Multimed Tools Appl 48(3):411-436, 2010) (for scenarios with permanent complete-overlapping among views) and propose a solution to this problem by exploiting the past visual data associated with each view, gathered over time as a panoramic image (sprite). The entire collection of temporal data from all the cameras is subsequently used for generating the side information. We tackle several topics related to these scenarios and propose solutions for the encountered issues. Optimization techniques are also discussed, e.g., temporal tags and block alternatives associated with the sprite contents for an improved generation of side information. This paper also presents a post-processing technique for additional refinement of generated side information. Practical results show an overall significant enhancement of side information by over 2 dB.

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