Translating sounds

P. 63-79El presente trabajo tiene como objetivo proporcionar información sobre cómo se reconocen y se traducen las palabras con programas de reconocimiento del habla. En la primera parte vamos a explicar brevemente la arquitectura de un programa de reconocimiento, basado en las plantillas, y los problemas que habitualmente se encuentran con este tipo de programas. En la segunda parte vamos a ofrecer una descripción detallada de las sesiones experimentales llevadas a cabo para comprobar el rendimiento del programar basado en plantillas con palabras aisladas y un pequeño vocabulario, con el problema añadido de múltiples altavoces con diferentes niveles de conocimiento de inglés. El análisis también incluirá comentarios sobre los patrones en el ordenamiento de los marcadores. Toda esta información puede ser relevante en la integración de estos sistemas en el proceso de enseñanza y aprendizaje de la pronunciación L

Wetland restoration and nitrate reduction: the example of the periurban wetland of Vitoria-Gasteiz (Basque Country, North Spain)

Changes in land use and agricultural intensification caused wetlands on the quaternary aquifer of Vitoria-Gasteiz (Basque Country) to disappear some years ago and nitrate concentration in groundwaters increased very quickly. The Basque Government recently declared the East Sector of this aquifer a Vulnerable Zone according to the 91/676/CEE European Directive. Recently, the wetlands have been restored through the closure of the main drainage ditches, the consequent elevation of the water table and the abondonment of agricultural practices near the wetlands. This is the case of the Zurbano wetland. Restoration has allowed the recovery of its biogeochemical function, which has reduced nitrate concentrations in waters. Nitrate concentrations which exceed 50 mg l–1 in groundwaters entering into the wetland are less than 10 mg l–1 at the outlet. Conditions in the wetland are conducive to the loss of nitrates: organic matter rich wetted soils, clay presence allowing a local semiconfined flow and very low hydraulic gradient. Water quality monitoring at several points around the wetland showed the processes involved in nitrate loss, although some aspects still remain unresolved. However, during storm events, the wetland effectively reduces the nitrate concentration entering the Alegria River, the most important river on the quaternary aquifer

Cost-efficient Selective Network Caching in Large-Area Vehicular Networks using Multi-objective Heuristics

In the last decade the interest around network caching tech- niques has augmented notably for alleviating the ever-growing demand of resources by end users in mobile networks. This gained momentum stems from the fact that even though the overall volume of traffic re- trieved from Internet has increased at an exponential pace over the last years, several studies have unveiled that a large fraction of this traffic is usually accessed by multiple end users at nearby locations, i.e. content demands are often local and redundant across terminals close to each other, even in mobility. In this context this manuscript explores the ap- plication of multi-objective heuristics to optimally allocate cache profiles over urban scenarios with mobile receivers (e.g. vehicles). To this end we formulate two conflicting objectives: the utility of the cache allocation strategy, which roughly depends on the traffic offloaded from the net- work and the number of users demanding contents; and its cost, given by an cost per unit of stored data and the rate demanded by the cached profile. Simulations are performed and discussed over a realistic vehicu- lar scenario modeled over the city of Cologne (Germany), from which it is concluded that the proposed heuristic solver excels at finding caching solutions differently balancing the aforementioned objectives

An Analysis of Coalition-Competition Pricing Strategies for Multi-Operator Mobile Traffic Offloading using Bi-objective Heuristics

In a competitive market relationships between telecommuni- cations operators serving simultaneously over a certain geographical area are diverse and motivated by very different business strategies and goals. Such relationships ultimately yield distinct pricing portfolios depending on the contractual affiliation of the user being served. Furthermore a key role in the last decade is the concept of tethering (connection sharing) which, when controlled by the operator, may help alleviating the con- sumption of network resources in densely populated scenarios. In this work we investigate the application of bi-objective heuristics for the de- sign of Pareto-optimal network topologies leading to an optimal Pareto between the revenue of the incumbent operators in the scenario and the quality of service degradation experienced by the end users as a result of tethering. Based on computer simulation this work unveils that such a Pareto-optimal set of topologies is strongly determined by the market relationships between such operators

Orbitofrontal dysfunction predicts poor prognosis in chronic migraine with medication overuse

Chronic migraine patients are at risk of developing a medication overuse. Brain functional studies in these patients have demonstrated an orbitofrontal hypometabolism, persistent after overuse cessation. Orbitofrontal dysfunction is also present in addiction and thus could predispose migraineurs to medication overuse. The aim of this study was to investigate if orbitofrontal dysfunction can be demonstrated in patients with chronic migraine and medication overuse by performing a systematic neuropsychological evaluation focused on tests that assess frontal lobe function. Second, to establish whether it is related to the outcome of these patients. We prospectively studied 42 chronic migraine patients with medication overuse, 42 episodic migraineurs and 41 controls on a battery of neuropsychological tasks evaluating the orbitofrontal and dorsolateral functioning. Depression, anxiety, and personality traits were also assessed. Chronic migraineurs with medication overuse showed a significant impairment in orbitofrontal task performance and higher depression scores as compared to episodic migraineurs and controls. Dorsolateral dysfunction was present in both groups of migraneurs, who also had higher rates of anxiety as compared to controls. After 1 year of follow-up, migraine patient’s outcome was classified according to their medication overuse status. A negative outcome that included persistent or new-onset medication overuse was present in 34% of migraineurs and was associated with baseline poor orbitofrontal task performance, and with mild dorsolateral dysfunction, higher rates of depression, anxiety and neuroticism-anxiety traits. Formal education and years with migraine did not influence outcome. Orbitofrontal dysfunction is present in patients with chronic migraine and medication overuse, and associates with a poor outcome at 1 year of follow-up. Neuropsychological evaluation in migraine may help to detect patients prone to overuse so that appropriate therapeutic attitudes can be taken

Therapeutic embolisation for postoperative haemorrhage after total arthroplasty of the hip and knee

We describe three cases of postoperative haemorrhage, two after total hip and one after total knee replacement, treated by percutaneous embolisation. After diagnostic angiography, this is the preferred method for the treatment of postoperative haemorrhage due to the formation of a false aneurysm, after hip or knee arthroplasty. This procedure, carried out under local anaesthesia, has a low rate of complications and avoids the uncertainty of further surgical exploratio

Análisis acústico comparado de las fricativas castellanas no sibilantes en realizaciones aisladas

En el presente trabajo de investigación se profundiza en las características acústicas de las fricativas castellanas no sibilantes en realizaciones aisladas. El estudio se centró en los espectros y espectrogramas y, dado que se trabajaba con habla natural no sintética, se tuvo en cuenta la acción de las variables “informante” y “articulación”. Para la grabación del material se emplearon ocho hablantes masculinos, lo que proporcionó un total de 80 estímulos (40 por fricativa). Los resultados del análisis demostraron que a pesar de la aparente semejanza de los espectrogramas se pueden señalar ciertas diferencias espectrales basadas en la distinta acción de los informantes y las variantes articulatorias. Se aportan así mismo nuevos datos de las frecuencias y amplitudes formánticas del sonido labiodental así como un estudio de la densidad media espectral del sonido dental