The acquisition of Tense and Aspect in Spanish

280 p.En esta tesis doctoral se investiga la adquisición de las marcas de aspecto y tiempo por parte de niños de 5 años (madrileños y navarros) que adquieren el español como lengua materna. Para su realización se han analizado, en primer lugar, cuáles son las características semánticas y pragmáticas de dichas formas y cuáles son las dificultades que supone su adquisición. En base a dicha investigación, se han diseñado una serie de tareas experimentales en las que se ha estudiado cuál es el conocimiento que tienen los niños de las marcas de tiempo y aspecto A) teniendo en cuenta tanto las formas sintéticas (formas simples, perfectivas e imperfectivas) como de formas perifrásticas (perfectos y progresivos), B) estudiando cada uno de los niveles ¿tiempo, aspecto gramatical y aspecto léxico¿ de manera separada y C) con una metodología experimental variada que incluye estudios de comprensión y producción con distintos tipos de tareas. Hemos podido constatar que a los 5 años de edad los niños pueden distinguir las marcas de pasado, presente y futuro y son capaces de utilizarlas de manera adecuada. Asimismo, también son capaces de distinguir las marcas de PF e IPF, pero su respuesta no es similar a la adulta en ciertas tareas debido a que no han adquirido aún los usos pragmáticos del IPF (no generan las implicaturas de escala asociadas al IPF) y tienen dificultades a la hora de identificar la referencia temporal del IPF. A nivel del aspecto del predicado, los niños en la edad de 5 todavía tienen problemas en identificar como télicos los predicados de tema incremental, dado que la telicidad con estos predicados depende del objeto y es generada pragmáticamente por una implicatura conversacional. Por último, se ha podido constatar que, aunque los niños muestran en producción una preferencia por las formas perifrásticas, la relativa complejidad morfológica y el grado de polisemia de las diferentes formas no afecta a la comprensión de las marcas de tiempo y aspecto

Interpretation of imperfective past tense in Spanish: how do child and adult language varieties differ?

Some studies on the L1 acquisition of aspect in various child languages have discovered that imperfective aspect is acquired later than perfective aspect, whereas others find early adultlike performance. A variety of explanations has been advanced, particularly problems (i) with the semantics of imperfective aspect in combination with telic predicates, (ii) inferring the intended temporal antecedent in a discourse, and (iii) reasoning about an agent’s intentions to complete the event when observing a situation of an event in progress. The current study aimed to disentangle which of the purported explanations can best explain the acquisition patterns. Twenty-three Spanish monolingual children (mean age 5;11) and 17 adults were presented with telic sentences with one of two aspectual tenses in Spanish (pretérito indefinido and pretérito imperfecto). Using a picture-selection task and presenting the sentences either in a narrative setting or in a non-narrative setting, participants were prompted to choose between complete, ongoing, and incomplete situations. In the non-narrative setting children’s interpretation of imperfecto was adult-like, but in the narrative setting it was not. The target-like interpretation in the non-narrative setting reveals that the semantics of imperfecto in telic-imperfective sentences has been acquired (contra explanation i). Furthermore, Spanish fiveyear-olds did not depend on cues for agent intentionality when interpreting the imperfecto (contra explanation iii). The discrepancy between narrative and non-narrative setting suggests the challenge lies in discourse integration (supporting explanation ii).This research was funded by COST, grant number A33. The I.G.-d.-R. was supported by the Basque Government (BFI08.176) and the MICINN (FFI2020-37884-C03-02). The A.v.H. was supported by a NIAS fellowship during the writing stage. The APC was funded by the Applied Linguistics Research Group (443) of the Public University of Navarre, as well as by the editors of the special issue in which this paper appears

La actividad metalingüística en una tarea de escritura colaborativa en Educación Primaria

Several studies have underscored the importance of the metalinguistic activity generated in collaborative writing tasks for the development of students’ writing competence. However, few of them have analyzed it in primary education contexts. This paper investigates the focus of the metalinguistic activity generated by nine pairs of fifth graders (10-11 years-old) in the prewriting, writing and revision stages of the collaborative production of a fable after a teaching intervention about this genre. To this aim, the episodes produced in the oral interactions were identified and analyzed in terms of focus and frequency. Results show that most episodes deal with textual and mechanical aspects, and that their focus varies according to the aims of the different stages of the task: text organization in the prewriting stage, and correction –focused merely on spelling– in the revision stage. The results obtained are discussed in relation to the effects of the intervention, the students’ cognitive maturity and the kind of correction usually made at school. Pedagogical recommendations are also given.Diversos estudios destacan el valor de la actividad metalingüística que se genera en tareas de escritura colaborativa para el desarrollo de la competencia escrita del alumnado. Sin embargo, pocos la han analizado en el contexto educativo de primaria. Este artículo investiga el contenido de la actividad metalingüística que nueve parejas de 5º curso (10-11 años) generan en las fases de preescritura, escritura y revisión de la producción colaborativa de una fábula tras una intervención didáctica sobre este género textual. Para ello, se identificaron los episodios metalingüísticos generados en las interacciones orales, y se analizó su contenido y su frecuencia. Los resultados muestran que la mayor parte de los episodios se refiere a aspectos textuales y mecánicos, y que su contenido varía de acuerdo al objetivo propio de cada fase de la tarea: la organización textual en la fase de preescritura, y la corrección, meramente ortográfica, en la fase de revisión. Los resultados obtenidos se discuten en relación con los efectos de la intervención didáctica, de la madurez cognitiva del alumnado y del tipo de corrección habitual en la escuela. Finalmente, se ofrecen algunas recomendaciones didácticas

Aplicación práctica de la gestión de inventarios en una empresa industrial

En este escrito se elabora un Trabajo Fin de Grado, dentro de la línea de Dirección de Operaciones del Grado de Administración y Dirección de Empresas de la Universidad de Zaragoza. Este trabajo consiste en la implementación de un modelo de inventarios en una empresa industrial, tanto para sus artículos con demanda dependiente como independiente. En la actualidad, esta empresa no dispone de un modelo o sistema concreto para gestionar sus inventarios, lo cual les afecta negativamente, provocándoles principalmente una reiterada falta de stocks en su almacén e impidiéndoles abastecer correctamente a sus clientes. Con este trabajo, se persigue mejorar la gestión de los inventarios de esta empresa y eliminar las rupturas de stocks, con el objetivo de mejorar los resultados económicos de la misma. Para ello se utilizará el modelo MRP para los artículos de la empresa con demanda dependiente y el EOQ para los artículos con demanda independiente

Real-Time Monitoring System for a Utility-Scale Photovoltaic Power Plant

There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant’s components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid

Children's non-adultlike interpretations of telic predicates across languages

The acquisition literature has documented several different types of misinterpretations of telic sentences by children, yet a comprehensive analysis of these child interpretations has not been attempted and a crosslinguistic perspective is lacking. This task is not easy, for, on the surface, children's non-adultlike interpretations appear to be scattered and even contradictory across languages. Several cognitive biases have been proposed to explain given patterns (children initially adhere to a Manner bias, or alternatively a Result bias). Reviewing a wide range of studies on the acquisition of telic sentences in relation to tense-aspect markers, we show that children's non-adultlike interpretations fall into three different patterns. We conclude that the diversity of non-adultlike interpretations that is found across child languages is incompatible with accounts that rely on these cognitive, language-independent principles, but instead is triggered by language-specific properties. Analyzing these patterns in detail, it appears that child learners across languages have problems with tense-aspect forms with variable meanings, in contrast to forms with a one-to-one form/meaning mappings which are acquired earlier. While adults use a context-sensitive interpretation of forms with multiple meanings, various semantic-pragmatic sources can explain children's difficulties with interpreting such forms. All explanations that we identify across child languages rely on children's immature command of pragmatic reasoning, albeit in very different ways for the three different patterns. Thus, by taking a crosslinguistic semantic approach and integrating detailed insights from the tense-aspect semantics of specific languages with universal pragmatic effects, we explain the non-adultlike interpretation of telic sentences in a variety of child languages in a comprehensive way.F. Martin was supported by the project B5 of the SFB 732 financed by the DFG and hosted by the University of Stuttgart, and by DFG award AL 554/8-1 (Leibniz-Preis 2014) to Artemis Alexiadou. I. García del Real was supported by the project MINECO/FEDER (FFI2015-68589-C2-1-P)

Monitoring of Energy Data with Seamless Temporal Accuracy Based on the Time-Sensitive Networking Standard and Enhanced μPMUs

In the energy sector, distributed synchronism and a high degree of stability are necessary for all real-time monitoring and control systems. Instantaneous response to critical situations is essential for the integration of renewable energies. The most widely used standards for clock synchronisation, such as Network Time Protocol (NTP) and Precision Time Protocol (PTP), do not allow for achieving synchronised simultaneous sampling in distributed systems. In this work, a novel distributed synchronism system based on the Time-Sensitive Networking (TSN) standard has been validated for its integration in an architecture oriented towards the high-resolution digitisation of photovoltaic (PV) generation systems. This method guarantees a time stamping with an optimal resolution that allows for the analysis of the influence of fast-evolving atmospheric fluctuations in several plants located in the same geographical area. This paper proposes an enhanced micro-phasor measurement unit (μPMU) that acts as a phasor meter and TSN master controlling the monitoring system synchronism. With this technique, the synchronism would be extended to the remaining measurement systems that would be involved in the installation at distances greater than 100 m. Several analyses were carried out with an on-line topology of four acquisition systems capturing simultaneously. The influence of the Ethernet network and the transducers involved in the acquisition process were studied. Tests were performed with Ethernet cable lengths of 2, 10, 50, and 75 m. The results were validated with 24-bit Sigma-Delta converters and high-precision resistor networks specialised in high-voltage monitoring. It was observed that with an appropriate choice of sensors and TSN synchronism, phase errors of less than ±1μs can be guaranteed by performing distributed captures up to 50 kS/s. Statistical analysis showed that uncertainties of less than ±100 ns were achieved with 16-bit Successive Approximation Register (SAR) converters at a moderate cost. Finally, the requirements of the IEEE C37.118.1-2011 standard for phasor measurement units (PMU) were also satisfied. This standard establishes an uncertainty of ±3.1 μs for 50 Hz systems. These results demonstrate the feasibility of implementing a simultaneous sampling system for distributed acquisition systems coordinated by a μPMU

Analysis of Some Power Quality Parameters at the Points of Common Coupling of Photovoltaic Plants Based on Data Measured by Inverters

With the increasing implementation of renewable energies, the impact that this type of installation can have on the electricity supply grid is of great importance. In this context, the aim of this work is to analyse how the production and injection of electricity generated by a series of small photovoltaic (PV) installations influence some parameters of the electricity grid in the low-voltage (LV) distribution networks to which they are connected, by analysing the basic data provided by the inverters of these installations. The presence of a slight rise in the grid voltage values in the Point of Common Coupling (PCC) as the production of the PV plants increases has been verified, with maximum slopes between 0.95 and 0.00027 V/kW, but which do not result in voltage values close to the limits set by the regulations. In addition to assessing this impact, the results obtained made it possible to determine the hosting capacity that the networks into which these installations inject their energy would have for this type of installation so as not to have a detrimental effect on the voltage values of the grid. The possible influence of the production of PV installations on the voltage imbalance between phases or on the frequency of the grid has also been analysed in this work. Although the values recorded by the inverters have limitations in their measurements that do not make them valid for assessing events such as the presence of harmonics or flickers, they do allow a first analysis to be made of the influence of PV plant production on some grid parameters, without the need to incorporate additional measurement systems in these renewable installations. However, it is important to be aware of the limitations of the measurements of this equipment and, as far as possible, to choose inverter models that carry out this type of measurement as completely as possible

Metalinguistic activity in a collaborative writing task in Primary Education

Diversos estudios destacan el valor de la actividad metalingüística que se genera en tareas de escritura colaborativa para el desarrollo de la competencia escrita del alumnado. Sin embargo, pocos la han analizado en el contexto educativo de primaria. Este artículo investiga el contenido de la actividad metalingüística que nueve parejas de 5º curso (10-11 años) generan en las fases de preescritura, escritura y revisión de la producción colaborativa de una fábula tras una intervención didáctica sobre este género textual. Para ello, se identificaron los episodios metalingüísticos generados en las interacciones orales, y se analizó su contenido y su frecuencia. Los resultados muestran que la mayor parte de los episodios se refiere a aspectos textuales y mecánicos, y que su contenido varía de acuerdo al objetivo propio de cada fase de la tarea: la organización textual en la fase de preescritura, y la corrección, meramente ortográfica, en la fase de revisión. Los resultados obtenidos se discuten en relación con los efectos de la intervención didáctica, de la madurez cognitiva del alumnado y del tipo de corrección habitual en la escuela. Finalmente, se ofrecen algunas recomendaciones didácticas.Several studies have underscored the importance of the metalinguistic activity generated in collaborative writing tasks for the development of students' writing competence. However, few of them have analyzed it in primary education contexts. This paper investigates the focus of the metalinguistic activity generated by nine pairs of fifth graders (10-11 years-old) in the prewriting, writing and revision stages of the collaborative production of a fable after a teaching intervention about this genre. To this aim, the episodes produced in the oral interactions were identified and analyzed in terms of focus and frequency. Results show that most episodes deal with textual and mechanical aspects, and that their focus varies according to the aims of the different stages of the task: text organization in the prewriting stage, and correction -focused merely on spelling- in the revision stage. The results obtained are discussed in relation to the effects of the intervention, the students' cognitive maturity and the kind of correction usually made at school. Pedagogical recommendations are also given

Do written plans determine texts' quality in primary school? An analysis of drafts and final texts in a collaborative writing task

Introducción: se ha observado que el uso de procedimientos de registro escrito durante la planificación previa redunda positivamente en la calidad de los textos escritos por alumnado adolescente y adulto, pero no en los realizados por alumnado de primaria. El presente trabajo pretende contribuir al conocimiento sobre el uso de procedimientos de planificación escrita por parte de alumnado de primaria y, especialmente, sobre su relación con la calidad de sus producciones finales, aportando datos procedentes de una tarea de escritura colaborativa de textos expositivo-argumentativos. Método: los participantes en el estudio fueron 66 estudiantes de 5º de primaria de dos centros españoles que produjeron un texto en parejas. Se analizaron, en primer lugar, los borradores para observar si el alumnado utilizó algún procedimiento de planificación escrita, y, en su caso, determinar su nivel de complejidad. En segundo lugar, se evaluó la calidad de los textos finales mediante una rúbrica y se cuantificó el número de ideas incluidas en ellos para comprobar si se observaban diferencias estadísticamente significativas en función de si el alumnado había empleado o no un procedimiento escrito de planificación previa. Resultados: los resultados muestran que la mayor parte del alumnado emplea un procedimiento escrito de planificación de nivel medio. Por otro lado, si bien el análisis estadístico muestra que no hay relación entre el uso o no uso de procedimientos de planificación y la calidad de los textos, el número de ideas contenidas en los textos finales es significativamente superior cuando se emplean técnicas de planificación. Discusión: en línea con otros estudios, se observa que el uso de procedimientos de planificación previa es un proceso emergente en estas edades que, si bien contribuye a enriquecer el contenido de los textos finales, no siempre redunda positivamente en la calidad de estos, por lo que debe trabajarse explícitamente en las aulas.Introduction: it has been observed that the use of written pre-planning strategies has a positive effect on the quality of final texts composed by teenage and adult students, but not on those produced by primary school children. By providing evidence from a collaborative writing task, this paper aims to contribute to existent knowledge about the use that primary school children make of written pre-planning strategies and its relation to the quality of the texts produced. Method: participants were sixty-six 5th graders from two Spanish schools who wrote an expository-argumentative text in pairs. First, we analyzed the drafts to observe whether students used written pre-planning strategies and, if so, we determined their complexity level. Second, we evaluated the quality of the final texts using a rubric and quantified the number of ideas they contained to search for statistically significant differences according to whether pre-planning strategies had been used or not. Results: results show that most students used a medium-level strategy. The statistical analysis showed no relationship between the quality of the final texts and the use of written pre-planning strategies. However, final texts written by students using these strategies contained significantly more ideas. Discussion: in line with other studies, we observe that the use of written pre-planning strategies is an emerging process at this age. When used, these strategies do not always have a positive effect on the quality of final texts but they do enrich their content. Therefore, they should be explicitly taught in class