23 research outputs found

    A generic template for the evaluation of dialogue management systems

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    We present a generic template for spoken dialogue systems integrating speech recognition and synthesis with 'higher-level' natural language dialogue modelling components. The generic model is abstracted from a number of real application systems targetted at very different domains. Our research aim in developing this generic template is to investigate a new approach to the evaluation of Dialogue Management Systems. Rather than attempting to measure accuracy/speed of output, we propose principles for the evaluation of the underlying theoretical linguistic model of Dialogue Management in a given system, in terms of how well it fits our generic template for Dialogue Management Systems. This is a measure of 'genericness' or 'application-independence' of a given system, which can be used to moderate accuracy/speed scores in comparisons of very unlike DMSs serving different domains. This relates to (but is orthogonal to) Dialogue Management Systems evaluation in terms of naturalness and like measurable metrics (eg. Dybkjaer et al 1995, Vilnat 1996, EAGLES 1994, Fraser 1995); it follows more closely emerging qualitative evaluation techniques for NL grammatical parsing schemes (Leech et al 1996, Atwell 1996)

    Using a commercial speech recogniser within the domain of air traffic control

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    We have taken an off-the-shelf, commercial continuous speech recogniser and conducted tests using three syntaxes for the domain of Air Traffic Control. The syntaxes are based on a corpus of transmissions between the ATC and pilots and reflect three differing levels of "linguistic" knowledge. The first represented the system where, in effect, there would be no syntax but a lexicon of all words in the corpus. The second took a partial look at syntactic information by using a key phrase spotting mechanism. The third represented the entire syntax of the corpus. Initial experiments show that key phrase spotting is insignificantly more accurate than no syntax at all, whilst use of a complete syntax can improve performance, to a point. The benefits of a discourse grammar are briefly discussed

    Observed Reductions in Schistosoma mansoni Transmission from Large-Scale Administration of Praziquantel in Uganda: A Mathematical Modelling Study

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    To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA) with praziquantel in Uganda over four years (2003-2006). In doing this we aim to elucidate the benefits of MDA in reducing community transmission.Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764). Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI), i.e., the rate of parasite acquisition by hosts.MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment.This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general

    Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with Schistosomiasis Control Initiative-assisted programmes

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    The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI)

    A new giraffid (Mammalia, Ruminantia, Pecora) from the late Miocene of Spain, and the evolution of the sivathere-samothere lineage

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    Giraffids include the only living giraffomorph ruminants and are diagnosed by the presence of bi-lobed canines and a special type of epiphyseal cranial appendages called ossicones. The family Giraffidae ranges from the latest early Miocene until today. However they are currently extant relics with only two living representatives, the African genera Okapia and Giraffa. Giraffids were much more diverse and widespread in the past, with more than 30 fossil species described. For the past decades a number of studies intended to resolve the phylogenetic relationships of the family, but due to the lack of really good cranial material no clear consensus was reached regarding the phylogenetic relationships amongst the different members of the group. The exceptionally complete remains of a new large giraffid from the late Miocene of Spain, Decennatherium rex sp. nov., allows us to improve and reassess giraffid systematics, offering a lot of new data, both anatomic and phylogenetic, on the large late Miocene giraffids of Eurasia. The results of our cladistic analysis show Decennatherium as a basal offshoot of a clade containing the gigantic samotheres and sivatheres, characterized by the presence of a Sivatherium-like ossicone-plan among other features. Decennatherium thus offers the most ancient evidence of this Sivatherium-plan and firmly establishes the early morphological patterns of evolution of a sivathere / samothere-clade that is defined as the less inclusive clade that contains Decennatherium and Sivatherium. Finally, this large group of four-ossiconed giraffids evolutionarily links Miocene Europe and Africa indicating vicariance / migration processes among the giraffid genetic pools separated by the Mediterranean Sea.MR acknowledges a FPI predoctoral grant (2012-2016) (Spanish Government MINECO http://www.mineco.gob.es/ codes: BES-2012-052589, EEBB-I-14-07947, EEBB-I-15-09349, EEBB-I-16-10617) as well as the EEBB-FPI grant program 2013, 2014 and 2015. IMS acknowledges the CERCA Program (Generalitat de Catalunya) and the CGL2016-76431-P research project by the Spanish Ministerio de Economía y Competitividad (http://www.mineco.gob.es/). This study was supported by the Spanish Ministerio de Economía y Competitividad (research projects CGL2011-25754 (2012-2015) and CGL2015-68333-P (2016-2019), http://www.mineco.gob.es/).Peer Reviewe
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