2014
Authors
Baquero, C; Almeida, PS; Shoker, A;
Publication
DISTRIBUTED APPLICATIONS AND INTEROPERABLE SYSTEMS (DAIS 2014)
Abstract
Conflict-free Replicated Datatypes (CRDT) are usually classified as either state-based or operation-based. However, the standard definition of op-based CRDTs is very encompassing, allowing even sending the full-state, blurring the distinction. We introduce pure op-based CRDTs, that can only send operations to other replicas, drawing a clear distinction from state-based ones. Datatypes with commutative operations can be trivially implemented as pure op-based CRDTs using standard reliable causal delivery. We propose an extended API - tagged reliable causal broadcast - that provides causality information upon delivery, and show how it can be used to also implement other datatypes having non-commutative operations, through the use of a PO-Log - a partially ordered log of operations - inside the datatype. A semanticallybased PO-Log compaction framework, using both causality and what we denote by causal stability, allows obtaining very compact replica state for pure op-based CRDTs, while also benefiting from small message sizes.
2014
Authors
Silva, GE; Caldas, P; Santos, JC; Santos, JL;
Publication
23RD INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS
Abstract
In this paper, we report the development of a reduced temperature sensitivity optical fiber sensor for refractive index measurement based on Superimposed Long-Period Gratings (SLPG) inscribed by the electric arc technique in standard fiber. The reduced sensitivity to temperature is achieved by calculation of the difference between resonance wavelengths of two guided cladding modes.
2014
Authors
Moreira Matias, L; Gama, J; Mendes Moreira, J; de Sousa, JF;
Publication
ADVANCES IN INTELLIGENT DATA ANALYSIS XIII
Abstract
In this paper, we presented a probabilistic framework to predict Bus Bunching (BB) occurrences in real-time. It uses both historical and real-time data to approximate the headway distributions on the further stops of a given route by employing both offline and online supervised learning techniques. Such approximations are incrementally calculated by reusing the latest prediction residuals to update the further ones. These update rules extend the Perceptron's delta rule by assuming an adaptive beta value based on the current context. These distributions are then used to compute the likelihood of forming a bus platoon on a further stop - which may trigger an threshold-based BB alarm. This framework was evaluated using real-world data about the trips of 3 bus lines throughout an year running on the city of Porto, Portugal. The results are promising.
2014
Authors
Santos, M.; Marinho, R., Magalhães, C., Lafuente, E., Cabral, S., Castro, H., Castelões, P.,; Oliveira, Bruno; Correia, Flora;
Publication
Abstract
[abstract]
2014
Authors
de Castro, R; Tanelli, M; Araujo, RE; Savaresi, SM;
Publication
VEHICLE SYSTEM DYNAMICS
Abstract
The new vehicle platforms for electric vehicles (ENTs) that are becoming available are characterised by actuator redundancy, which makes it possible to jointly optimise different aspects of the vehicle motion. To do this, high-level control objectives are first specified and solved with appropriate control r strategies. Then, the resulting virtual control action must be translated into actual actuator commands by a control allocation layer that takes care of computing the forces to be applied at the wheels. This step, in general, is quite demanding as for as computational complexity is considered. In this work, a safety-oriented approach to this problem is proposed. Specifically, a four-wheel steer EV with four in-wheel motors is considered, and the high-level motion controller is designed within a sliding mode framework with conditional integrators. For distributing the forces among the tyres, two control allocation approaches are investigated. The first, based on the extension of the cascading generalised inverse method, is computationally efficient but shows some limitations in dealing with unfeasible force values. To solve the problem, a second allocation algorithm is proposed, which relies on the linearisation of the tyre road friction constraints. Extensive tests, carried out in the CarSim simulation environment, demonstrate the effectiveness of the proposed approach.
2014
Authors
Catarino, A; Rocha, AM; Abreu, MJ; Derogarian, F; Da Silva, J; Ferreira, J; Tavares, V; Correia, M; Dias, R;
Publication
Journal of Textile Engineering
Abstract
Human motion capture systems help clinicians to detect and identify mobility impairments, early stages of pathologies and evaluate the effectiveness of surgical or rehabilitation intervention. Although there is a considerable number of solutions presently available, these systems are often expensive, complex, difficult to wear, and uncomfortable for the patient. With the purpose of solving the formerly mentioned problems, a new wearable locomotion data capture system for gait analysis is being developed. This system will allow the measurement of several locomotion-related parameters in a practical and non-invasive way, also reusable, that can be used by patients from light to severe impairments or disabilities. © 2013 The Textile Machinery Society of Japan.
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.