Testing the aspect first hypothesis : A preliminary investigation into the comprehension of tense in child greek

Crosslinguistic research on the production of tense morphology in child language has shown that young children use past or perfective forms mainly with telic predicates and present or imperfective forms mainly with atelic predicates. However, this pattern, which has come to be known as the Aspect First Hypothesis, has been challenged in a number of comprehension studies. These studies suggest that children do not rely on aspectual information for their interpretation of tense morphology. The present paper tests the validity of the Aspect First Hypothesis in child Greek by investigating Greek-speaking children’s early comprehension of present, past and future tense morphology as well as the role that lexical aspect plays in the early use of tense morphology. It is suggested that although Greek-speaking children have not yet fully mapped the tense concepts to the correct tense morphology, tense acquisition does not seem to be significantly affected by the aspectual characteristics (i.e. the telicity) of the verb

Non-commutative NLS-type hierarchies: dressing & solutions

We consider the generalized matrix non-linear Schrodinger (NLS) hierarchy. By employing the universal Darboux-dressing scheme we derive solutions for the hierarchy of integrable PDEs via solutions of the matrix Gelfand-Levitan-Marchenko equation, and we also identify recursion relations that yield the Lax pairs for the whole matrix NLS-type hierarchy. These results are obtained considering either matrix-integral or general $n^{th}$ order matrix-differential operators as Darboux-dressing transformations. In this framework special links with the Airy and Burgers equations are also discussed. The matrix version of the Darboux transform is also examined leading to the non-commutative version of the Riccati equation. The non-commutative Riccati equation is solved and hence suitable conserved quantities are derived. In this context we also discuss the infinite dimensional case of the NLS matrix model as it provides a suitable candidate for a quantum version of the usual NLS model. Similarly, the non-commutitave Riccati equation for the general dressing transform is derived and it is naturally equivalent to the one emerging from the solution of the auxiliary linear problem.Comment: 29 pages, LaTex. Minor modification

Time-like boundary conditions in the NLS model

We focus on the non-linear Schrodinger model and we extend the notion of space-time dualities in the presence of integrable time-like boundary conditions. We identify the associated time-like `conserved' quantities and Lax pairs as well as the corresponding boundary conditions. In particular, we derive the generating function of the space components of the Lax pairs in the case of time-like boundaries defined by solutions of the reflection equation. Analytical conditions on the boundary Lax pair lead to the time like-boundary conditions. The time-like dressing is also performed for the first time, as an effective means to produce the space components of the Lax pair of the associated hierarchy. This is particularly relevant in the absence of a classical r-matrix, or when considering complicated underlying algebraic structures. The associated time Riccati equations and hence the time-like conserved quantities are also derived. We use as the main paradigm for this purpose the matrix NLS-type hierarchy.Comment: 17 pages, LaTex. A few typos corrected. arXiv admin note: substantial text overlap with arXiv:1810.1093

Chapter 05: A Brief Introduction to Instructional Message Design in Synchronous Online Learning Technologies

This chapter will analyze and discuss concepts related to instructional message design as it relates to synchronous online learning technologies. Synchronous online learning is becoming increasingly popular especially in the pandemic era and it is able to provide students with a lot of opportunities and benefits for their learning processes. This chapter specifically will provide an analysis of the major benefits and challenges of synchronous online learning technologies. It will also discuss learning platforms such as Zoom, that can be used to further provide the reader with concrete examples of an online tool that is able to successfully develop a synchronous and virtual classroom environment. Synchronous, real-time, active learning is an ever evolving toolset that instructional designers can use to engage and create social presence in online classes

Offering help in Greek: Divergence from the native-speaker norm and developmental patterns in Greek FL learners’ performance of offers

This study investigates developmental patterns in the ability of Greek foreign language learners to make offers. Drawing data from role-plays and retrospective verbal reports it attempts to explore the initial offer strategies and the degree of insistence that learners of three different proficiency levels (lower intermediate, intermediate and advanced) employ when performing offers in different social situations.The results suggest that, although there is a great deal of grammatical and pragma-linguistic development in regard to both initial offer strategies and syntactic modification devices, this does not guarantee concomitant levels of socio-pragmatic development (cf. Bardovi-Harlig 1999)