2014
Autores
Dias, R; da Silva, JM;
Publicação
2014 11TH INTERNATIONAL CONFERENCE ON WEARABLE AND IMPLANTABLE BODY SENSOR NETWORKS WORKSHOPS (BSN WORKSHOPS)
Abstract
The work presented herein addresses the development, implementation, and evaluation of a new wearable system for monitoring bio-signals and physical human activity, namely for gait analysis and cardiovascular surveillance. It consists of a wearable textile substrate (pantyhose and/or T-shirt) with embedded conductive yarns interconnecting custom electronic devices, in a mesh or other network type, that acquire bio-signals and/or inertial data. All data are aggregated in a central processing module from where they are sent via a wireless link to a mobile phone or personal computer for final processing. The network topology, sensor nodes architecture and results obtained with first prototypes are presented.
2014
Autores
Sousa, R; Moura, DC; Dinis Ribeiro, M; Coimbra, MT;
Publicação
2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC)
Abstract
Local descriptors coupled with robust methods for learning visual dictionaries have been a pivotal tool in computer vision. Although the identification of similar patterns is commonly conducted on some stage of the bag-of-words framework, a prior assessment of spatial local similarities can be indicative of specific objects, and thus improved recognition rates. In this work we delve a function of similarity for enhancing the discriminative power of local constrained SIFT descriptors. Motivated by gastrointestinal images where diagnosis through endoscopy plays a decisive role in cancer detection and resulting prognosis, visual cues in these early stages are slim and of difficult perception. In order to capture these patterns we propose a self-similarity approach (based on a neighbourhood analysis of SIFT descriptors) to assess local variances through a weight function. Based on extensive simulations our approach achieved a performance of 88%: 3% higher than the standard SIFT, 10% higher than Haar wavelet and 13% higher than LBPs.
2014
Autores
Nunes, LJR; Matias, JCO; Catalão, JPS;
Publicação
Renewable Energy and Power Quality Journal
Abstract
During the last decade wood pellets consumption grew rapidly. In this paper the development of the wood pellet production factors for markets in Germany, Sweden and Portugal are compared. Domestic market prices for pellet production factors as well as domestic market prices for pellets variation are analysed. The analysis are based on two model plants, representing the first common technologies for small scale production based on dry sawdust sources, and the second represents large scale production based on wet materials. The results show how differences in costs of raw materials, energy and labour affects wood pellets production. The economic sustainability for European pellet producers depends on their domestic markets as internationally traded pellets are priced lower than their production costs, being Portugal an exception due to lower labour and raw materials costs. Future pellet production will be based on wet raw materials such as logs and wet sawdust. These raw materials are also demanded by pulp and paper or fiberboard industries. The transition from smaller wood pellets plants using dry raw materials to larger plants using wet raw materials, can be expected to follow comparative advantages regarding raw materials, energy costs and economies of scale.
2014
Autores
Conceição, S; Ribeiro, F; Campos, R; Ricardo, M;
Publicação
2014 IFIP Wireless Days, WD 2014, Rio de Janeiro, Brazil, November 12-14, 2014
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 IEEE.
2014
Autores
Ramos, AG; Jacob, J; Justo, J; Oliveira, JF; Rodrigues, R; Gomes, AM;
Publicação
26th European Modeling and Simulation Symposium, EMSS 2014
Abstract
In the Container Loading Problem literature, the cargo dynamic stability constraint has been evaluated by the percentage of boxes with insufficient lateral support. This metric has been used as a proxy for the real-world dynamic stability constraint and has conditioned the algorithms developed for this problem. It has the advantage of not being expensive from a computation perspective. However, guaranteeing that at least three sides of a box are in contact with another box or with the container wall does not necessarily ensure stability during transportation. In this paper we propose a physics simulation tool based on a physics engine that will be used in the evaluation of the dynamic stability constraint. We compare the results of our physics simulation tool with the state-of-the-art simulation engineering software Abaqus Unified FEA, and conclude that our tool is a promising alternative.
2014
Autores
Layeghi, A; Latifi, H; Frazao, O;
Publicação
IEEE PHOTONICS TECHNOLOGY LETTERS
Abstract
A novel magnetic field sensor using a nonadiabatic tapered optical fiber (NATOF) interacting with magnetic fluid (MF) nanoparticles is proposed and experimentally demonstrated. The NATOF sensitivity when is subjected to refractive index (RI) measurement in the small range from 1.3380 to 1.3510 was 1260.17 nm/RIU as a refractometer sensor. The NATOF is surrounded by a MF whose RI changes with external magnetic field, which MF is as a cladding of tapered fiber. The output interference spectrum is shifted by the change of the applied magnetic field intensity in the range up to 44 mT with a sensitivity of -7.17 x 10(-2) nm/mT, used only 0.1% of the volume concentration of MF nanoparticles. This direct manipulation of light with magnetic fields provides an approach to develop future sensors relying on electromagnetic interactions.
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