M. Oliver O'Mahony

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This paper presents solutions towards an efficient and intelligent network infrastructure for Grid services, taking advantage of recent developments in optical-networking technologies. Two lambda-Grid network architectures based on extensions to existing wavelength-switched network infrastructure are discussed. These network solutions aim to provide a(More)
This paper presents views on the future of optical networking. A historical look at the emergence of optical networking is first taken, followed by a discussion on the drivers pushing for a new and pervasive network, which is based on photonics and can satisfy the needs of a broadening base of residential, business, and scientific users. Regional plans and(More)
This paper presents the results of the optical packet switched network (OPSnet) project, which investigated the design of an asynchronous optical packet switch suitable for the core of an optical transport network (OTN). The requirements for the switch were to control and route variable-length packets transmitted at bit rates beyond 100 Gbit/s. The(More)
As wavelength converters based on four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) attract more attention, dynamic effects and wavelength dependent performance become key aspects to be investigated. Such issues are particularly important, as complex configurations are likely to be used to overcome challenges like tunability and polarization(More)
This paper describes the design and development of a Web syndication intermediary that works with various syndication technologies, specifically the RSS family and Atom. We developed format-neutral middleware that sits between content sources and the user. Another objective was to add a recommendation component transparently to the intermediary. Implicit(More)
BACKGROUND Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. METHODS AND RESULTS In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial(More)
Two optical crosstalk mechanisms, homo- and hetero-wavelength crosstalk, are identified in multi-wavelength switched networks. Homo-wavelength crosstalk does not arise in point-point systems and is a significant factor in multi-wavelength network design. A new signal dependent statistical model was used to evaluate the crosstalk effects due to non-ideal(More)
Four wave mixing (FWM) is distinguished from other wavelength conversion techniques by its ability to simultaneously convert a number of input wavelength channels. In this case, optical signal-to-noise ratio (OSNR) is insufficient to describe the performance of the device as many effects are involved. A multiwavelength FWM model is used here to simulate a(More)