A hybrid strategy for real-time traffic signal control of urban road networks

The recently developed traffic signal control strategy known as traffic-responsive urban control (TUC) requires availability of a fixed signal plan that is sufficiently efficient under undersaturated traffic conditions. To drop this requirement, the well-known Webster procedure for fixed-signal control derivation at isolated junctions is appropriately employed for real-time operation based on measured flows. It is demonstrated via simulation experiments and field application that the following hold: 1) The developed real-time demand-based approach is a viable real-time signal control strategy for undersaturated traffic conditions. 2) It can indeed be used within TUC to drop the requirement for a prespecified fixed signal plan. 3) It may, under certain conditions, contribute to more efficient results, compared with the original TUC method

ESTABLISHING A METHODOLOGY FOR BENCHMARKING SPEECH SYNTHESIS FOR COMPUTER-ASSISTED LANGUAGE LEARNING (CALL)

Despite the new possibilities that speech synthesis brings about, few Computer-Assisted Language Learning (CALL) applications integrating speech synthesis have found their way onto the market. One potential reason is that the suitability and benefits of the use of speech synthesis in CALL have not been proven. One way to do this is through evaluation. Yet, very few formal evaluations of speech synthesis for CALL purposes have been conducted. One possible reason for the neglect of evaluation in this context is the fact that it is expensive in terms of time and resources. An important concern given that there are several levels of evaluation from which such applications would benefit. Benchmarking, the comparison of the score obtained by a system with that obtained by one which is known, to guarantee user satisfaction in a standard task or set of tasks, is introduced as a potential solution to this problem. In this article, we report on our progress towards the development of one of these benchmarks, namely a benchmark for determining the adequacy of speech synthesis systems for use in CALL. We do so by presenting the results of a case study which aimed to identify the criteria which determine the adequacy of the output of speech synthesis systems for use in its various roles in CALL with a view to the selection of benchmark tests which will address these criteria. These roles (reading machine, pronunciation model, and conversational partner) are also discussed here. An agenda for further research and evaluation is proposed in the conclusion

X-ray Emission near the Substellar Limit: The sigma Orionis and Taurus Star Forming Regions

We have carried out an extensive search for X-ray emission from young, very low-mass objects near and beyond the substellar limit, making use of archived ROSAT PSPC and HRI observations pointed at Brown Dwarfs and Brown Dwarf candidates in the young sigma Orionis and Taurus-Auriga associations. In sigma Ori we identify three Brown Dwarf candidates with X-ray sources; in Taurus-Auriga we add one further X-ray detection of a Brown Dwarf to the list published earlier. We combine this data with all previously X-ray detected Brown Dwarfs and Brown Dwarf candidates in young stellar associations and star forming regions to perform a study of stellar activity parameters on the as yet largest sample of young, very low mass objects. A similar relation between X-ray and bolometric luminosity, and H-alpha emission, respectively, as is known for T Tauri stars seems to hold for young objects down to the substellar limit, too. No signs for a change in X-ray activity are found on the transition to substellar masses.Comment: 9 pages, 5 (9) figures; fig. 1-4 are available only in the preprint or in the ps-file via , accepted for publication in A&

Four-features evaluation of text to speech systems for three social robots

The success of social robotics is directly linked to their ability of interacting with people. Humans possess verbal and non-verbal communication skills, and, therefore, both are essential for social robots to get a natural human&-robot interaction. This work focuses on the first of them since the majority of social robots implement an interaction system endowed with verbal capacities. In order to do this implementation, we must equip social robots with an artificial voice system. In robotics, a Text to Speech (TTS) system is the most common speech synthesizer technique. The performance of a speech synthesizer is mainly evaluated by its similarity to the human voice in relation to its intelligibility and expressiveness. In this paper, we present a comparative study of eight off-the-shelf TTS systems used in social robots. In order to carry out the study, 125 participants evaluated the performance of the following TTS systems: Google, Microsoft, Ivona, Loquendo, Espeak, Pico, AT&T, and Nuance. The evaluation was performed after observing videos where a social robot communicates verbally using one TTS system. The participants completed a questionnaire to rate each TTS system in relation to four features: intelligibility, expressiveness, artificiality, and suitability. In this study, four research questions were posed to determine whether it is possible to present a ranking of TTS systems in relation to each evaluated feature, or, on the contrary, there are no significant differences between them. Our study shows that participants found differences between the TTS systems evaluated in terms of intelligibility, expressiveness, and artificiality. The experiments also indicated that there was a relationship between the physical appearance of the robots (embodiment) and the suitability of TTS systems.The research leading to these results has received funding from the projects: “Development of social robots to help seniors with cognitive impairment (ROBSEN)”, funded by the Ministerio de Economía y Competitividad; “RoboCity2030-DIH-CM”, funded by Comunidad de Madrid and co-funded by Structural Funds of the EU; “Robots Sociales para estimulación física, cognitiva y afectiva de mayores (ROSES)” funded by Agencia Estatal de Investigación (AEI).Publicad

Thematic patterning in English and Arabic and its implications on translation

This thesis examines patterns of thematization between English and Arabic, demonstrating variations in textual meaning and implications of such an examination on the activity and education of translation. Translators frequently encounter the challenge of positioning clausal constituents at the beginning of a sentence when translating from English to Arabic. The study, drawing on Halliday’s SFL theory, applies the system of Theme as a tool to the analysis of an English text and six Arabic translations to investigate such variations. The analysis also aims to demonstrate to what extent thematic patterning is preserved or changed between the original and target text. The results show that there are cases of unjustified deviation, leading to translational shifts and changes in the intended textual meaning. The study argues that thematic patterns are not arbitrary, but imply textual meanings that should be rendered to the target language as they reflect the author’s intentions and method of text development and reader’s orientation. This thesis concludes that changes in thematic patterning between English and Arabic is attributed to the translator’s lack of understanding of the textual meanings underlying such patterns and lack of resources in Arabic to equivalently recreate such meanings. Furthermore, it presents the system of Theme as an objective metalinguistic tool for translation analysis, critique, and education

On the development of an automatic voice pleasantness classification and intensity estimation system

In the last few years, the number of systems and devices that use voice based interaction has grown significantly. For a continued use of these systems, the interface must be reliable and pleasant in order to provide an optimal user experience. However there are currently very few studies that try to evaluate how pleasant is a voice from a perceptual point of view when the final application is a speech based interface. In this paper we present an objective definition for voice pleasantness based on the composition of a representative feature subset and a new automatic voice pleasantness classification and intensity estimation system. Our study is based on a database composed by European Portuguese female voices but the methodology can be extended to male voices or to other languages. In the objective performance evaluation the system achieved a 9.1% error rate for voice pleasantness classification and a 15.7% error rate for voice pleasantness intensity estimation.Work partially supported by ERDF funds, the Spanish Government (TEC2009-14094-C04-04), and Xunta de Galicia (CN2011/019, 2009/062

Variation in habitat preference and distribution of harbour porpoises west of Scotland

The waters off the west coast of Scotland have one of the highest densities of harbour porpoise (Phocoena phocoena) in Europe. Harbour porpoise are listed under Annex II of the EU Habitats Directive, requiring the designation of Special Areas of Conservation (SACs) for the species’ protection and conservation. The main aim of this thesis is to identify habitat preferences for harbour porpoise, and key regions that embody these preferences, which could therefore be suitable as SACs; and to determine how harbour porpoise use these regions over time and space. Designed visual and acoustic line-transect surveys were conducted between 2003 and 2008. Generalised Estimating Equations (GEEs) were used to determine relationships between the relative density of harbour porpoise and temporally and spatially variable oceanographic covariates. Predictive models showed that depth, slope, distance to land and spring tidal range were all important in explaining porpoise distribution. There were also significant temporal variations in habitat use. However, whilst some variation was observed among years and months, consistent preferences for water depths between 50 and 150 m and highly sloped regions were observed across the temporal models. Predicted surfaces revealed a consistent inshore distribution for the species throughout the west coast of Scotland. Regional models revealed similar habitat preferences to the full-extent models, and indicated that the Small Isles and Sound of Jura were the most consistently important regions for harbour porpoise, and that these regions could be suitable as SACs. The impacts of seal scarers on distribution and habitat use were also investigated, and there were indications that these devices have the potential to displace harbour porpoise. These results should be considered in the assessment of sites for SAC designation, and in implementing appropriate conservation measures for harbour porpoise