Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

2007

Towards a Coordination Model for Interactive Systems

Authors
Barbosa, MA; Barbosa, LS; Campos, JC;

Publication
Electronic Notes in Theoretical Computer Science

Abstract
When modelling complex interactive systems, traditional interactor-based approaches suffer from lack of expressiveness regarding the composition of the different interactors present in the user interface model into a coherent system. In this paper we investigate an alternative approach to the composition of interactors for the specification of complex interactive systems which is based on the coordination paradigm. We layout the fundations for the work and present an illustrative example. Lines for future work are identified.

2007

Using low voltage MicroGrids for service restoration

Authors
Moreira, CL; Resende, FO; Lopes, JAP;

Publication
IEEE TRANSACTIONS ON POWER SYSTEMS

Abstract
Under normal operating conditions, a MicroGrid is interconnected with the medium voltage network; however, in order to deal with black start and islanded operation following a general blackout, an emergency operation mode must be envisaged. A sequence of actions and conditions to be checked during the restoration stage are identified and tested through numerical simulation. Voltage and frequency control approaches, inverter control modes, and the need of storage devices are addressed in this paper in order to ensure system stability, achieve robustness of operation, and not jeopardize power quality during service restoration in the low voltage area.

2007

Optical flowmeter using a modal interferometer based on a single nonadiabatic fiber taper

Authors
Frazao, O; Caldas, P; Araujo, FM; Ferreira, LA; Santos, JL;

Publication
OPTICS LETTERS

Abstract
A novel in-fiber modal interferometer is presented that is based on a nonadiabatic biconical fused taper that couples light between the cladding and the core, combined with the Fresnel reflection at the fiber end. It is observed that the returned light from this fiber structure shows a channeled spectrum similar to that of a two-wave Michelson interferometer. The application of this device as a fiber optic flowmeter sensor is demonstrated. 2007 (c) Optical Society of America.

2007

A relação entre a percepção de competência física, índice de massa corporal e competência efectiva em jovens praticantes de basquetebol

Authors
Ferreira, S; Fernandes, HM; Vasconcelos-Raposo, J;

Publication
Motricidade

Abstract

2007

A data-driven approach for pipelining sequences of data-dependent loops

Authors
Rodrigues, R; Cardoso, JMP; Diniz, PC;

Publication
FCCM 2007: 15TH ANNUAL IEEE SYMPOSIUM ON FIELD-PROGRAMMABLE CUSTOM COMPUTING MACHINES, PROCEEDINGS

Abstract
Many video and image/signal processing applications can be structured as sequences of data-dependent tasks using a consumer/producer communication paradigm and are therefore amenable to pipelined execution. This paper presents an execution technique to speed-up the overall execution of successive, data-dependent tasks on a reconfigurahle architecture. The technique pipelines sequences of data-dependent tasks by overlapping their execution subject to data-dependences. It decouples the concurrent data-path and control units and uses a custom, application data-driven, fine-grained synchronization and buffering scheme. In addition, the execution scheme allows for out of-order, but data-dependent producer-consumer pairs not allowed by previous data-driven pipelining approaches. The approach has been exploited in the context of a high-level compiler targeting FPGAs. The preliminary experimental results reveal noticeable performance improvements and buffer size reductions for a number of benchmarks over traditional approaches.

2007

All-fiber Mach-Zehnder curvature sensor based on multimode interference combined with a long-period grating

Authors
Frazao, O; Viegas, J; Caldas, P; Santos, JL; Araujo, FM; Ferreira, LA; Farahi, F;

Publication
OPTICS LETTERS

Abstract
A novel Mach-Zehnder interferometer based on a fiber multimode interference structure combined with a long-period fiber grating (LPG) is proposed. The multimode interference is achieved through the use of a MMF section spliced between two single-mode fibers, with a length adjusted to couple a fraction of light into the cladding modes. A LPG placed after the MMF couples light back into the fiber core, completing the Mach-Zehnder interferometer. This novel configuration was demonstrated as a bending sensor. (c) 2007 Optical Society ofAmerica.

  • 4098
  • 4536