2004
Authors
Pereira, N; Tovar, E; Pinho, LM;
Publication
IEEE COMPUTER SOCIETY'S 12TH ANNUAL INTERNATIONAL SYMPOSIUM ON MODELING, ANALYSIS, AND SIMULATION OF COMPUTER AND TELECOMMUNICATIONS SYSTEMS - PROCEEDINGS
Abstract
The continuous improvement of Ethernet technologies is boosting the eagerness of extending their use to also cover factory-floor distributed real time applications. Indeed, it is remarkable the considerable amount of research work that has been devoted to the timing analysis of Ethernet-based technologies in the past few years. It happens, however, that the majority of those works are restricted to the analysis of sub-sets of the overall computing and communication system, thus without addressing timeliness in a holistic fashion. To this end, in this paper we address an approach, based on simulation, aiming at extracting temporal properties of Commercial-Off-The-Shelf (COTS) Ethernet-based factory-floor distributed systems. This framework is being applied to a specific COTS technology, Ethernet/IP. In this paper, we reason about the modeling and simulation of Ethernet/IP-based systems, and on the use of statistical analysis techniques to provide useful results on timeliness.
2004
Authors
Pereira, N; Tovar, E; Pinho, LM;
Publication
WFCS 2004: IEEE INTERNATIONAL WORKSHOP ON FACTORY COMMUNICATION SYSTEMS, PROCEEDINGS
Abstract
In the past few years, a significant amount of work has been devoted to the timing analysis of Ethernet-based technologies. However, none of these address the problem of timeliness evaluation at a holistic level. This paper describes a research framework embracing this objective. It is advocated that, simulation models can be a powerful tool, not only for timeliness evaluation, but also to enable the introduction of less pessimistic assumptions in an analytical response time approach, which, most often, are afflicted with simplifications leading to pessimistic assumptions and, therefore. delusive results. To this end, we address a few inter-linked research topics with the purpose of setting a framework for developing tools suitable to extract temporal properties of Commercial-Off-The-Shelf (COTS) factory-floor communication systems.
2004
Authors
Manuel, L; Oliveira, C;
Publication
SARATOV FALL MEETING 2003: OPTICAL TECHNOLOGIES IN BIOPHYSICS AND MEDICINE V
Abstract
Port Wine ageing process is very important to produce the most appreciated and expensive wines from the class. The process takes decades to accomplish and involves particular techniques which are taken inside refrigerated cellars. Different wines pass through such process to produce 10 year, 20 year, 30 year and 40 year Ports. There are no documented data about color or turbidity evolution during the ageing process. We decided to verify the states of color and spectral turbidity of different aged Gold white port wine. The acquired results show a spectral evolution on transmition and scattered radiation along with color modification which are a close and direct consequence of adopted corrective measures. In measuring the four samples, we have used our spectronephelometer with optical fiber tips to illuminate sample and to acquire transmitted or scattered radiation. Transmition results were calibrated with a standard spectrophotometer at our laboratory, and scattered spectra were measured considering a system calibration with ISO12103 standard dust. We are aware that the four samples were harvested in different years, but the wine type is the same and the ageing process does not differ from one sample to another.
2003
Authors
Mendonca, HS; da Silva, JM; Matos, JS;
Publication
IMTC/O3: PROCEEDINGS OF THE 20TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1 AND 2
Abstract
The estimation of the harmonic content of an ADC output is fundamental to evaluate its suitability to perform according the requirements specified for an application. The use of the traditional frequency analysis leads to a large hardware overhead due to the amount of on-chip processing being involved, or to a large quantity of data to be transferred in case the processing is performed in a tester. This paper presents an algorithm capable of estimating the harmonics with similar accuracy but with the advantage of being more suitable for a BIST implementation, since it requires a reduced number of on-chip operations, and that only a small set of values has to be supplied outside the chip for further processing. It relies, on the fact that harmonics generated by an ADC are mathematical related with the polynomial coefficients of its transfer function. ADC offset and gain errors can also be measured.
2003
Authors
Rego, G; Santos, JL; Marques, PVS; Salgado, HM;
Publication
Optics InfoBase Conference Papers
Abstract
We have investigated the possibility to erase arc-induced long period gratings through uniform exposure to UV-laser radiation and their potential recover by thermal annealing. The temperature stability of UV/arc-induced gratings is also presented. © 2000 Optical Society of America.
2003
Authors
Romero, R; Salgado, HM; Frazão, O; Marques, PVS; Santos, JL;
Publication
Optics InfoBase Conference Papers
Abstract
A chirped fibre Bragg grating was written in an Erbium doped fibre. It was found that the slope of the reflected spectral power could be tuned by changing the pump power. The gratings fabricated were demonstrated to be useful in the development of a technique for optical interrogation of FBGs sensing heads with tunable sensitivity. © 2003 OSA/BGPP.
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