2014
Authors
Calcada, T; Ricardo, M;
Publication
TELECOMMUNICATION SYSTEMS
Abstract
Stub Wireless Mesh Networks (WMNs) are used to extend Internet access. The use of multiple channels improves the capacity of WMN but significant challenges arise when nodes are limited to a single-radio interface to form the WMN. In particular, the assignment of mesh nodes to channels results on the creation of multiple sub-networks, one per channel, where individual capacity may depend on the sub-network topologies This paper identifies the relevant topological characteristics of the sub-networks resultant from the channel assignment process and studies, through simulation, the impact and relative importance of those characteristics on the maximal throughput enabled by the stub WMN. The number of nodes in the gateways neighborhood and the hidden node problem in the gateways neighborhood were identified as the characteristics having the highest impact on the WMN throughput.
2014
Authors
Conceicao, S; Ribeiro, F; Campos, R; Ricardo, M;
Publication
2014 IFIP Wireless Days (WD)
Abstract
Wireless Underground Networks (WUNs) include communications links between buried nodes and between buried and aboveground nodes. WUNs have many applications, such as border surveillance, agriculture monitoring, and infrastructure monitoring. Recent studies have shown that they are feasible and have deployment advantages over wired networks. Yet, so far WUNs evaluations have been done using testbeds only, and a tool enabling simulations on TCP/IP WUNs is lacking. We propose a simulator of TCP/IP wireless underground networks based on ns-3. The simulator was validated against experimental results for 433 MHz and 2.4 GHz frequency bands. The results show its accuracy for most of the communications scenarios.
2014
Authors
Soares, M; Viana, P;
Publication
ADVANCES IN ELECTRICAL AND COMPUTER ENGINEERING
Abstract
The expansion of Digital Television and the convergence between conventional broadcasting and television over IP contributed to the gradual increase of the number of available channels and on demand video content. Moreover, the dissemination of the use of mobile devices like laptops, smartphones and tablets on everyday activities resulted in a shift of the traditional television viewing paradigm from the couch to everywhere, anytime from any device. Although this new scenario enables a great improvement in viewing experiences, it also brings new challenges given the overload of information that the viewer faces. Recommendation systems stand out as a possible solution to help a watcher on the selection of the content that best fits his/her preferences. This paper describes a web based system that helps the user navigating on broadcasted and online television content by implementing recommendations based on collaborative and content based filtering. The algorithms developed estimate the similarity between items and users and predict the rating that a user would assign to a particular item (television program, movie, etc.). To enable interoperability between different systems, programs' characteristics (title, genre, actors, etc.) are stored according to the TV-Anytime standard. The set of recommendations produced are presented through a Web Application that allows the user to interact with the system based on the obtained recommendations.
2014
Authors
Chambel, T; Viana, P; Bove, VM; Strover, S; Thomas, G;
Publication
Proceedings of the ACM International Conference on Multimedia - MM '14
Abstract
2014
Authors
Chambel, T; Viana, P; Bove, VM; Strover, S; Thomas, G;
Publication
PROCEEDINGS OF THE 2014 ACM CONFERENCE ON MULTIMEDIA (MM'14)
Abstract
The 2nd ACM International Workshop on Immersive Media Experiences (ImmersiveMe'14) at ACM Multimedia aims at bringing together researchers, students, media producers, service providers and industry players in the emergent area of immersive media experiences, through the exploration of different scenarios, applications, and neighboring fields. This second edition, after a successful first edition at ACM Multimedia 2013, provides a platform for presenting on-going work, to consolidate and tie different research communities working on this engaging area, as well as to point directions for the future.
2014
Authors
Salazar Escobar, AJS; da Silva, JM; Correia, M;
Publication
2014 19TH INTERNATIONAL MIXED-SIGNALS, SENSORS AND SYSTEMS TEST WORKSHOP (IMS3TW)
Abstract
The framework being proposed addresses the test and measurement of circuits and systems populated with varying types of sensors and functional blocks, among which one can find embedded test instruments. Its conceptual functionality is based on four types of operations: setup, capture, process, and scan (SCPS), and aims to provide a unifying methodology for managing and synchronizing test operations and instruments. The generalized physical structure and examples of operating commands are described. An application illustrates its use in a particular case.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.