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Publications

2018

Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands

Authors
de Almeida, JMMM; Vasconcelos, H; Jorge, PAS; Coelho, L;

Publication
SENSORS

Abstract
It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR) with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO2) substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS) and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of similar to 60 nm/RIU was calculated, for the repeated dewetting, a value of similar to 186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency.

2018

Path Patterns Visualization in Semantic Graphs

Authors
Leal, JP;

Publication
7th Symposium on Languages, Applications and Technologies, SLATE 2018, June 21-22, 2018, Guimaraes, Portugal

Abstract
Graphs with a large number of nodes and edges are difficult to visualize. Semantic graphs add to the challenge since their nodes and edges have types and this information must be mirrored in the visualization. A common approach to cope with this difficulty is to omit certain nodes and edges, displaying sub-graphs of smaller size. However, other transformations can be used to abstract semantic graphs and this research explores a particular one, both to reduce the graph’s size and to focus on its path patterns. Antigraphs are a novel kind of graph designed to highlight path patterns using this kind of abstraction. They are composed of antinodes connected by antiedges, and these reflect respectively edges and nodes of the semantic graph. The prefix “anti” refers to this inversion of the nature of the main graph constituents. Antigraphs trade the visualization of nodes and edges by the visualization of graph path patterns involving typed edges. Thus, they are targeted to users that require a deep understanding of the semantic graph it represents, in particular of its path patterns, rather than to users wanting to browse the semantic graph’s content. Antigraphs help programmers querying the semantic graph or designers of semantic measures interested in using it as a semantic proxy. Hence, antigraphs are not expected to compete with other forms of semantic graph visualization but rather to be used a complementary tool. This paper provides a precise definition both of antigraphs and of the mapping of semantic graphs into antigraphs. Their visualization is obtained with antigraphs diagrams. A web application to visualize and interact with these diagrams was implemented to validate the proposed approach. Diagrams of well-known semantic graphs are also presented and discussed. © José Paulo Leal.

2018

Assessing how green space types affect ecosystem services delivery in Porto, Portugal

Authors
Graca, M; Alves, P; Goncalves, J; Nowak, DJ; Hoehn, R; Farinha Marques, P; Cunha, M;

Publication
LANDSCAPE AND URBAN PLANNING

Abstract
Significant advances have been made in identifying, quantifying and valuing multiple urban ecosystem services (UES), yet this knowledge remains poorly implemented in urban planning and management. One of the reasons for this low implementation is the insufficient thematic and spatial detail in UES research to provide guidance for urban planners and managers. Acknowledging how patterns of UES delivery are related with vegetation structure and composition in urban green areas could help these stakeholders to target structural variables that increase UES provision. This investigation explored how different types of urban green spaces influence UES delivery in Porto, a Portuguese city, and how this variation is affected by a socioeconomic gradient. A stepwise approach was developed using two stratification schemes and a modelling tool to estimate urban forest structure and UES provision. This approach mapped explicit cold and hotspots of UES provision and discriminated the urban forest structural variables that influence UES at the local scale. Results revealed that different types of green spaces affect UES delivery as a direct result of the influence of structural variables of the urban forest. Furthermore, the uneven distribution of green spaces types across socioeconomic strata alters UES delivery across the city. This case study illustrates how a methodology adaptable to other geographic contexts can be used to map and analyze coupled social and ecological patterns, offering novel insights that are simple to understand and apply by urban planners and managers.

2018

Facing the Challenges of Nostalgia International Markets

Authors
Carrizo Moreira, A; Alves, V; Martins, T; Pereira, JB; Conceição, S;

Publication
Advances in Logistics, Operations, and Management Science - Enhancing Competitive Advantage With Dynamic Management and Engineering

Abstract
Internationalization is a business strategy that normally aims at expanding the business of the firm outside its domestic market. It may also involve the creation of an integrated network of contacts and partners. The aim of this chapter involves a firm that distributes high-end wines and other alcoholic drinks to the domestic market and is seeking to expand its activities abroad. Taking into account the “nostalgia market,” with many Portuguese living throughout Europe, this chapter seeks to analyze how a Portuguese firm seeks to embrace the internationalization strategy of serving these ex-pats, through local retailers, and afterwards the possibility of serving the market abroad using the contacts so far developed. As such, the firm seeks to serve both the ex-pats and the local market alike. The chapter analyzes the Spanish, French, and German market, and it is possible to conclude that France is the market with the higher likelihood of success, economically and culturally.

2018

Promoting heritage through a pervasive and mobile computing approach: The case of the Portuguese city of Mirandela

Authors
Cunha, CR; Morais, EP; Alves, A;

Publication
Proceedings of the 31st International Business Information Management Association Conference, IBIMA 2018: Innovation Management and Education Excellence through Vision 2020

Abstract
Promoting Heritage is a challenge for all generations. The heritage is a legacy that we inherit from our ancestors and that we should deliver to our decedents. In this sense, the first steep that we should take, after preserve the heritage, is to develop solutions that enable effective and democratic ways to promote it. This promotion starts with the ability that of those who visit this heritage be able to know and enjoy it. Information and Communication Technologies and specifically Pervasive and Mobile Computing represents nowadays a big opportunity to develop innovative solutions capable to inform tourists about heritage and even enable them to experience past realities related to immaterial heritage like ancestral legends, past events and even no longer existing physical patrimony. This paper starts to make a reflection and the evolution the Information and Communication Technologies role on tourism and present a technological architecture to respond to the challenge of promote heritage and inform tourist in their travel experiences. After that, the paper presents also a developed prototype created to the Portuguese City of Mirandela capable to promote its historical and gastronomic heritage and also support the tours of the tourists through its territory. Finally, there are made some remarks about the future growing and directions for technology applied to tourism.

2018

cf2vec: Collaborative Filtering algorithm selection using graph distributed representations

Authors
Cunha, T; Soares, C; de Carvalho, ACPLF;

Publication
CoRR

Abstract

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