Memory-Based Lexical Acquisition and Processing

Current approaches to computational lexicology in language technology are knowledge-based (competence-oriented) and try to abstract away from specific formalisms, domains, and applications. This results in severe complexity, acquisition and reusability bottlenecks. As an alternative, we propose a particular performance-oriented approach to Natural Language Processing based on automatic memory-based learning of linguistic (lexical) tasks. The consequences of the approach for computational lexicology are discussed, and the application of the approach on a number of lexical acquisition and disambiguation tasks in phonology, morphology and syntax is described.Comment: 18 page

Acoustic emission waveform picking with time delay neural networks during rock deformation laboratory experiments

We report a new method using a time delay neural network to transform acoustic emission (AE) waveforms into a time series of instantaneous frequency content and permutation entropy. This permits periods of noise to be distinguished from signals. The model is trained in sequential batches, using an automated process that steadily improves signal recognition as new data are added. The model was validated using AE data from rock deformation experiments, using Darley Dale sandstone in fully drained conditions at a confining pressure of 20 MPa (approximately 800 m simulated depth). The model is initially trained by manual picking of five high-amplitude waveforms randomly selected from the dataset (experiment). This is followed by semisupervised training on a subset of 300 waveforms

Proceedings of QG2010: The Third Workshop on Question Generation

These are the peer-reviewed proceedings of "QG2010, The Third Workshop on Question Generation". The workshop included a special track for "QGSTEC2010: The First Question Generation Shared Task and Evaluation Challenge". QG2010 was held as part of The Tenth International Conference on Intelligent Tutoring Systems (ITS2010)

Arabic and Chinese learners' production, perception and processing of past tense and verbal agreement morphology in L2 English

PhD ThesisThis thesis is an attempt to locate the source of the difficulties experienced by adult second language (L2) learners of English in the production of past tense and verbal agreement morphology, observed as an alternation between the inflected and stem forms of verbs in contexts where only the former is accepted in target grammars. To this end, current competing syntactic, non-syntactic and phonological accounts of the phenomenon are tested against production, perception and processing data. Production was tested by a sentence elicited imitation task, which comprised of 50 aural sentences creating obligatory contexts for the properties under study. Participants were asked to repeat the sentences one by one and their response was recorded. Perception and processing were tested by a computerised picture-choice task, which consisted of 88 picture-sentence trials. Participants were asked to choose one picture, the choice of which depended on their perception of verbal morphology. Picture choice response, reaction times and eye movements were recorded in this task. Thirty-seven L1 speakers of Chinese and thirty-four L1 speakers of Arabic, who were matched in L2 proficiency at low, mid and high levels, in addition to a control group of ten native speakers of English participated in the study. The results of the production and perception studies similarly showed that while Chinese participants produced and perceived the morphology variably at all levels, Arab participants did so only at low and mid levels, overcoming variability at the highest proficiency level. Neither production nor perception data demonstrated phonological effects. Results from the processing study revealed that both language groups processed the morphology similarly at low and mid levels but they differed at the high level with only Arab participants’ data showing evidence for developing automatic competence. These findings strongly suggest that morphological variability is caused by absence of syntactic representations which are built up incrementally with rising proficiency supporting structure building accounts of L2 acquisition

Synthetic Amorphous Silicon Dioxide (NM-200, NM-201, NM-202, NM-203, NM-204): Characterisation and Physico-Chemical Properties

The European Commission's Joint Research Centre (JRC) provides scientific support to European Union policy including nanotechnology. Within this context, the JRC launched, in February 2011, a repository for Representative Test Materials (RTMs), based on preparatory work started in 2008. It supports both EU and international research projects, and especially the OECD Working Party on Manufactured Nanomaterials (WPMN). The WPMN leads an exploratory testing programme "Testing a Representative set of Manufactured Nanomaterials" for the development and collection of data on characterisation, toxicological and ecotoxicological properties, as well as risk assessment and safety evaluation of nanomaterials. The purpose is to understand the applicability of the OECD Test Guidelines for the testing of nanomaterials as well as end-points relevant for such materials. The Repository responds to a need for nanosafety research purposes: availability of nanomaterial from a single production batch to enhance the comparability of results between different research laboratories and projects. The availability of representative nanomaterials to the international scientific community furthermore enhances and enables development of safe materials and products. The present report presents the physico-chemical characterisation of the synthetic amorphous silicon dioxide (SiO2, SAS) from the JRC repository: NM-200, NM-201, NM-202, NM-203 and NM-204. NM-200 was selected as principal material for the OECD test programme "Testing a representative set of manufactured nanomaterials". NM-200, NM-201 and NM-204 (precipitated SAS) are produced via the precipitation process, whereas NM-202 and NM-203 (fumed or pyrogenic SAS) are produced via a high temperature process. Each of these NMs originates from one respective batch of commercially manufactured SAS. They are nanostructured, i.e. they consist of aggregated primary particles. The SAS NMs may be used as a representative material in the measurement and testing with regard to hazard identification, risk and exposure assessment studies. The results for more than 15 endpoints are addressed in the present report, including physical-chemical properties, such as size and size distribution, crystallite size and electron microscopy images. Sample and test item preparation procedures are addressed. The results are based on studies by several European laboratories participating to the NANOGENOTOX Joint Action, as well as the JRC.JRC.I.4-Nanobioscience

El papel de la frecuencia del input en la adquisición de la fonología del español como L1. Estudio basado en corpus

This study presents the phonological system exhibited by children (n=59) aged 3;0 to 6;0 and focuses on the role of input frequency. Using a spontaneous child speech corpus of Spanish (CHIEDE) as a data source, as well as computational processing techniques —including an automatic phonological transcriber—, data relating to the phonological level was retrieved. This resulted in a phonological inventory of Spanish-speaking children, ordered by frequency of use, which may serve as a model for research on typical and atypical child language development. Additionally, a study was carried out on the stability of the participants’ phonological systems by calculating the variability that the different age groups displayed, and outcomes were compared with other similar corpora. Results obtained from the comparison of the phonological inventory of children and adults show that there is a relationship between frequency of use in adult speech and the order of acquisition of phonemesEste estudio presenta el sistema fonológico que muestran 59 participantes de 3;0 a 6;0 años y el papel que juega la frecuencia del input. Usando como fuente un corpus de habla espontánea (CHIEDE) y técnicas de procesamiento computacional —que incluyen un transcriptor fonológico automático— se extrajeron los datos relativos al nivel fonológico, dando como resultado un inventario fonológico de niños hablantes de español. Este in-ventario, ordenado por frecuencia de uso, puede servir de modelo para la investigación en desarrollo infantil típico y atípico. Además, se realizó un estudio sobre la estabilidad del sistema fonológico de los participantes, calculando la variabilidad entre los diferentes grupos etarios y comparando resultados con otros corpus similares. Los resultados obtenidos de la comparación del inventario infantil con el adulto muestran una clara relación entre la frecuencia de uso del habla adulta y el orden de adquisición de los fonema