Evaluación automática de preguntas abiertas en el aula

El feedback es un elemento educativo básico en el proceso de enseñanza y aprendizaje. Dentro de esta retroalimentación, el feedback inmediato que se da en el aula hace que impacte de forma más directa en el estudiante, intensificando su aprendizaje. Por ello, las soluciones que permiten la interacción entre docentes y estudiantes se utilizan cada vez con más frecuencia en el aula. Por otra parte, el avance de técnicas de Procesamiento del Lenguaje Natural en los últimos años es imparable, teniendo su máxima expresión en los modelos de lenguaje basados en arquitectura de Transformers. En este trabajo se lleva a cabo un estudio sobre cómo integrar modelos de lenguaje en el aula para proporcionar feedback en tiempo real a los estudiantes. La propuesta consiste en evaluar de forma automática respuestas a preguntas abiertas en el aula utilizando inteligencia artificial. Los resultados obtenidos son prometedores, logrando los mejores resultados en la evaluación cuando se proporciona la máxima información posible al modelo: la pregunta, la respuesta y la rúbrica de evaluación

Below-ground biomass and productivity of a grazed site and a neighbouring ungrazed exclosure in a grassland in central Argentina

We estimated the below-ground net plant productivity (BNPP) of different biomass components in an intensively and continuously 45-ha grazed site and in a neighbouring exclosure ungrazed for 16 years for a natural mountain grassland in central Argentina. We measured approximately twice as much dead below-ground biomass in the grazed site as in the ungrazed site, with a strong concentration of total below-ground biomass towards the upper 10 cm of the soil layer in both sites. The main contribution to total live biomass was accounted for by very fine (1 mm) in the grazed site. The seasonal variation of total live below-ground biomass mainly reflected climate, with the growing season being limited to the warmer and wetter portion of the year, but such variation was higher in the grazed site. Using different methods of estimation of BNPP, we estimated maximum values of 1241 and 723 g m-2 year -1 for the grazed and ungrazed sites, respectively. We estimated that very fine root productivity was almost twice as high at the grazed site as at the ungrazed one, despite the fact that both sites had similar total live biomass, and root turnover rate was twofold at the grazed site.Fil: Pucheta, Eduardo Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Bonamici, Ivano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Díaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Scatter Search Particle Filter to Solve the Dynamic Travelling Salesman Problem

Abstract. This paper presents the Scatter Search Particle Filter (SSPF) algorithm and its application to the Dynamic Travelling Salesman Problem (DTSP). SSPF combines sequential estimation and combinatorial optimization methods to improve the execution time in dynamic optimization problems. It allows obtaining new high quality solutions in subsequent iterations using solutions found in previous time steps. The hybrid SSPF approach increases the performance of general Scatter Search (SS) metaheuristic in dynamic optimization problems. We have applied the SSPF algorithm to different DTSP instances. Experimental results have shown that SSPF performance is significantly better than classical DTSP approaches, where new solutions of derived problems are obtained without taking advantage of previous solutions corresponding to similar problems. Our proposal reduces execution time appreciably without affecting the quality of the estimated solution.

Vegetation types of the Arid Chaco in Central-Western Argentina

Aims: We address the following questions: 1) Which are the main vegetation types that currently occur in the Arid Chaco? 2) Do those vegetation types differ in terms of floristic composition, endemism, chorotypes and life forms? and 3) Is there any spatial association between the vegetation types and the environmental heterogeneity of the Arid Chaco? Study area: The southwestern extreme of the Gran Chaco, in Central-Western Argentina. Methods: The survey was based on a dataset comprising 654 relevés collected according to the Braun-Blanquet method. Data were classified by the hierarchical ISOmetric feature mapping and Partition Around Medoids (ISOPAM), and ordinated through isometric feature mapping (ISOMAP). Bioclimatic and edaphic variables were related to the ISOMAP ordination. Results: We recorded 439 vascular plant species, 62 endemic at the national level and 22 endemic species restricted to the study and surrounding environments in Central-Western Argentina. A total of nine vegetation types, belonging to four major clusters, were identified. The most prominent chorotypes included species distributed in the Chaco region and in the Arid Chaco/Monte phytogeographic units. The predominant life forms were micro- and nano-phanerophytes, followed by hemicryptophytes, chamaephytes and mesophanerophytes. Conclusions: Major results highlighted that xerophytic shrublands are the most common vegetation types in this area as a result of the historical and present use, while old growth forests were constrained to areas with low anthropogenic disturbance in the last decades or to protected areas. Most vegetation types (with the exception of halophytic environments) are poorly differentiated from a floristic point of view; however, they clearly differ in physiognomy. The floristic composition of the vegetation types described revealed numerous species in common with other sectors of the Chaco of northern Argentina, Bolivia and Paraguay. Although the number of species restricted to the Arid Chaco was quite low, the most relevant chorotype included species with Western and Eastern Chaco distribution, conferring a clear Chaquenian identity to this area and discriminating it from other phytogeographic units. Taxonomic reference: Catálogo de las Plantas Vasculares del Cono Sur (Zuloaga et al. 2008) and its online update (http://www.darwin.edu.ar). Abbreviations: ISOMAP = isometric feature mapping; ISOPAM = isometric partitioning around medoids