2011
Authors
Frazao, O; Silva, SO; Viegas, J; Ferreira, LA; Araujo, FM; Santos, JL;
Publication
APPLIED OPTICS
Abstract
This paper presents an overview of optical fiber sensors based on multimode interference with a focus on refractometric applications. A specific configuration is presented to measure the refractive index of the surrounding liquid based on the Fresnel reflection in the fiber tip, combined with a simple interrogation technique that uses two fiber Bragg gratings as discrete optical sources, with the measurand information encoded in the relative intensity variation of the reflected signals. A resolution of 1.75 x 10(-3) RIU is achieved. (C) 2011 Optical Society of America
2011
Authors
Haq, IU; Salgado, HM; Castro, JCS;
Publication
International Congress on Ultra Modern Telecommunications and Control Systems and Workshops
Abstract
Resource contention is a major concern in Optical Burst Switching networks that leads to relatively high burst loss probability. This article presents a clustered architecture for OBS networks, called Cooperative Clustered Optical Burst Switching (C2OBS) network architecture. In this architecture, the network is divided in overlapping zones/clusters with a zone/cluster head having the knowledge of available resources within the zone called Zonal Base (ZB) and maintains a short resource usage history called Short History Base (SHB). A resource reservation strategy for the proposed Cooperative Clustered OBS network architecture (C2OBS-RR) is also presented which is centralized within the zone and distributed in the overall network, for combining the benefits of both the centralized and the distributed resource reservation schemes. This novel approach uses the local state of the resource availability within the zone (ZB) so that the bursts originating at the ingress nodes in the same part of network having been assigned the same wavelength, can be assigned different time offsets. This will proactively reduce the probability of contention at the intermediate nodes within a zone and is expected to significantly reduce the overall network burst loss probability. For illustration purpose, the proposed C2OBS architecture has been applied to the European Optical Network. © 2011 HTE.
2011
Authors
Wielemaker, J; Costa, VS;
Publication
PRACTICAL ASPECTS OF DECLARATIVE LANGUAGES
Abstract
The non-portability of Prolog programs is widely considered one of the main problems facing Prolog programmers. Although since 1995, the core of the language is covered by the ISO standard 13211-1, this standard has not been sufficient to support large Prolog applications. As an approach to address this problem, since 2007, YAP and SWI-Prolog have established a basic compatibility framework. The aim of the framework is running the same code on Edinburgh-based Prolog systems rather than having to migrate an application. This article describes the implementation and evaluates this framework by studying how it can be used on a number of libraries and an important application.
2011
Authors
Marques, PVS; Ghasempour, A; Alexandre, D; Leite, AMP; Garcia, PJV; Reynaud, F;
Publication
INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS
Abstract
Integrated optics is a well established technology that finds its main applications in the fields of optical communication and sensing. However, it is expanding into new areas, and in the last decade application in astronomical interferometry has been explored. In particular, several examples have been demonstrated in the areas of beam control and combination. In this paper, different examples of application integrated optics devices for fabrication of beam combiners for astronomical interferometry is given. For the multiaxial beam combiners, a UV laser direct writing unit is used for mask fabrication. The operation principles of the coaxial combiners fabricated in hybrid sol-gel were validated using an interferometric set-up. These results demonstrate that hybrid sol-gel technology can produce quality devices, opening the possibility of rapid prototyping of new designs and concepts.
2011
Authors
Aguiar, A; Merson, P;
Publication
Proceedings of the 7th International Symposium on Wikis and Open Collaboration, 2011, Mountain View, CA, USA, October 3-5, 2011
Abstract
Using a wiki in software engineering settings dates back to its first usage in 1995. In fact, that was the motivation for Ward Cunningham to create the first wiki. Due to its simplicity, attractiveness and effectiveness for collaborative authoring and knowledge management, wikis are now massively disseminated and used in different domains. This workshop focuses on wikis for the specific domain of software engineering. It aims at bringing together researchers, practitioners, and enthusiasts interested on researching, exploring and learning how wikis can be improved, customized and used to better support software projects. Based on lessons learned and obstacles identified, a research agenda will be defined with key opportunities and challenges. © 2011 Authors.
2011
Authors
Catalao, JPS; Pousinho, HMI; Mendes, VMF;
Publication
IET RENEWABLE POWER GENERATION
Abstract
The increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges because of its intermittency and volatility. Hence, good forecasting tools play a key role in tackling these challenges. In this study, a hybrid intelligent approach is proposed for short-term wind power forecasting in Portugal. The proposed approach is based on the wavelet transform and a hybrid of neural networks and fuzzy logic. Results from a real-world case study are presented. A thorough comparison is carried out, taking into account the results obtained with other approaches. Conclusions are duly drawn.
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