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

2014

Introduction: Structural change, competitiveness and industrial policy

Authors
Da Silva, EG; Teixeira, AAC;

Publication
Structural Change, Competitiveness and Industrial Policy: Painful Lessons from the European Periphery

Abstract

2014

Phase-sensitive Optical Time Domain Reflectometer Assisted by First-order Raman Amplification for Distributed Vibration Sensing Over 100 km

Authors
Martins, HF; Martin Lopez, S; Corredera, P; Filograno, ML; Frazao, O; Gonzalez Herraez, M;

Publication
JOURNAL OF LIGHTWAVE TECHNOLOGY

Abstract
In this study, the authors present an experimental and theoretical description of the use of first order Raman amplification to improve the performance of a Phase-sensitive optical time domain reflectometer (phi OTDR) when used for vibration measurements over very long distances. A special emphasis is given to the noise which is carefully characterized and minimized along the setup. A semiconductor optical amplifier and an optical switch are used to greatly decrease the intra-band coherent noise of the setup and balanced detection is used to minimize the effects of RIN transferred from the Raman pumps. The sensor was able to detect vibrations of up to 250 Hz (close to the limits set by the time of flight of light pulses) with a resolution of 10 m in a range of 125 km. To achieve the above performance, no post-processing was required in the fOTDR signal. The evolution of the fOTDR signal along the fiber is also shown to have a good agreement with the theoretical model.

2014

Fluid evaporation monitoring with suspended-core fibers

Authors
Mouraa, JP; Baierl, H; Auguste, JL; Jamier, R; Roy, P; Santos, JL; Frazao, O;

Publication
SECOND INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

Abstract
A new configuration for volatile organic compound sensing is proposed. A sub-milimiter four-hole suspended core optical fiber tip, spliced to a standard single mode fiber, is dipped in a liquid volatile compound and the reflected signal is continuously interrogated. When the fiber is immersed in acetone it suffers a 1 4 dB signal drop. Different menisci form in each cladding cavity, with different evaporation times and rates. The signal restores its initial state not when the evaporation process is complete but after the collapse of a dominant meniscus.

2014

ISTTOK real-time architecture

Authors
Carvalho, IS; Duarte, P; Fernandes, H; Valcarcel, DF; Carvalho, PJ; Silva, C; Duarte, AS; Neto, A; Sousa, J; Batista, AJN; Hekkert, T; Carvalho, BB;

Publication
Fusion Engineering and Design

Abstract
The ISTTOK tokamak was upgraded with a plasma control system based on the Advanced Telecommunications Computing Architecture (ATCA) standard. This control system was designed to improve the discharge stability and to extend the operational space to the alternate plasma current (AC) discharges as part of the ISTTOK scientific program. In order to accomplish these objectives all ISTTOK diagnostics and actuators relevant for real-time operation were integrated in the control system. The control system was programmed in C++ over the Multi-threaded Application Real-Time executor (MARTe) which provides, among other features, a real-time scheduler, an interrupt handler, an intercommunications interface between code blocks and a clearly bounded interface with the external devices. As a complement to the MARTe framework, the BaseLib2 library provides the foundations for the data, code introspection and also a Hypertext Transfer Protocol (HTTP) server service. Taking advantage of the modular nature of MARTe, the algorithms of each diagnostic data processing, discharge timing, context switch, control and actuators output reference generation, run on well-defined blocks of code named Generic Application Module (GAM). This approach allows reusability of the code, simplified simulation, replacement or editing without changing the remaining GAMs. The ISTTOK control system GAMs run sequentially each 100 µs cycle on an Intel® Q8200 4-core processor running at 2.33 GHz located in the ATCA crate. Two boards (inside the ATCA crate) with 32 analog-to-digital converters (ADCs) were used for acquiring the diagnostics data. Each ADC operates at 2 Msample/s but (for real-time operation) the acquired data is decimated in real-time on the board's Field-programmable gate array (FPGA) to a frequency defined by the control cycle time. This paper presents the ISTTOK real-time architecture and the human-machine Interface (HMI) for simplified AC discharge programming. © 2014 Instituto de Plasmas e Fusão Nuclear.

2014

A testing and certification methodology for an open Ambient-Assisted Living ecosystem

Authors
Faria, JP; Lima, B; Sousa, TB; Martins, A;

Publication
International Journal of E-Health and Medical Communications

Abstract
To cope with the needs raised by the demographic changes in our society, several Ambient-Assisted Living (AAL) technologies have emerged in recent years, but those 'first offers' are often monolithic, incompatible and thus expensive and potentially not sustainable. The AAL4ALL project aims at improving that situation through the development of an open ecosystem of interoperable AAL components (products and services), tied together by an integration infrastructure, comprising a message-queue based service bus and gateways bridging the communication with devices. To that end, the project encompasses the specification of interfaces and requirements for interoperable components, against which candidates can be tested and certified before entering the ecosystem. This paper proposes a testing and certification methodology for such an ecosystem. Besides fulfilling specified pre-requisites, candidate components must pass unit tests that check their conformance with interface specifications and integration tests that check their semantic interoperability with other components in specified orchestration scenarios. Copyright © 2014, IGI Global.

2014

Editorial

Authors
Pinho L.;

Publication
Ada User Journal

Abstract

  • 2751
  • 4198