Constraint cumulativity in phonotactics: evidence from artificial grammar learning studies

An ongoing debate in phonology concerns the treatment of cumulative constraint interactions, or ‘gang effects’, and by extension the question of which phonological frameworks are suitable models of the grammar. This paper uses a series of artificial grammar learning experiments to examine the inferences that learners draw about cumulative constraint violations in phonotactics in the absence of a confounding natural-language lexicon. I find that learners consistently infer linear counting and ganging cumulativity across a range of phonotactic violations.

Learning Sensitivity of RCPSP by Analyzing the Search Process

Solving the problem is an important part of optimization. An equally important part is the analysis of the solution where several questions can arise. For a scheduling problem, is it possible to obtain a better solution by increasing the capacity of a resource? What happens to the objective value if we start a specific task earlier? Answering such questions is important to provide explanations and increase the acceptability of a solution. A lot of research has been done on sensitivity analysis, but few techniques can be applied to constraint programming. We present a new method for sensitivity analysis applied to constraint programming. It collects information, during the search, about the propagation of the CUMULATIVE constraint, the filtering of the variables, and the solution returned by the solver. Using machine learning algorithms, we predict if increasing/decreasing the capacity of the cumulative resource allows a better solution. We also predict the impact on the objective value of forcing a task to finish earlier. We experimentally validate our method with the RCPSP problem.

Cumulative constraint interaction and the equalizer of OT and HG

We show that, in general, Optimality Theory (OT) grammars containing a restricted family of locally-conjoined constraints (Smolensky 2006) make the same typological predictions as corresponding Harmonic Grammar (HG) grammars. We provide an intuition for the generalization using a simple constrast and neutralization typology, as well as a formal proof. This demonstration adds structure to claims about the (non)equivalence of HG and OT with local conjunction (Legendre et al. 2006, Pater 2016) and provides a tool for understanding how different sets of constraints lead to the same typological predictions in HG and OT.

Dative intervention is a gang effect

This paper addresses two restrictions regarding agreement with nominative arguments in Icelandic DAT-NOM constructions. The first is the reported asymmetry in intervention effects in mono-clausal versus bi-clausal environments. The second regards the well-known Person Restriction that prohibits agreement with non-3rd person arguments. It is argued that both of these phenomena can be viewed as instances of cumulative constraint interaction, where less important constraints in the grammar ‘gang up’ to block some higher constraint. In order to account for this, I adopt a model of syntax with both weighted constraints and serial optimization that is known as Serial Harmonic Grammar in the phonological literature. It will be demonstrated that such a system can offer a more principled analysis of the construction-specific nature of the aforementioned phenomena.

External syntax and the Cumulative Effect in subject sub-extraction: An experimental evaluation

In this paper, we test the Cumulative Effect proposed by (Haegeman et al. 2014. Deconstructing the subject condition in terms of cumulative constraint violation.

Formation and evolution of nuclear star clusters

Nuclear stellar clusters (NSCs) are dense stellar systems known to exist at the center of most of the galaxies. Some of them host a central massive black hole (MBH). They are though to form through in-situ star formation following the infall of gas to the galactic center and/or because of the infall and merger of several stellar clusters. Here we explore the latter scenario by means of detailed self-consistent N-body simulations, proving that a NSC built by the infall and following merger of stellar clusters shows many of the observed features of the Milky Way NSC. We also explore the possibility that the infalling clusters host intermediate mass black holes (IMBHs). Once decayed to the center, the IMBHs act as massive-perturbers accelerating the relaxation of the NSC, filling the loss-cone and boosting the tidal disruption rate of stars up to a value larger than the observational estimates, therefore providing a cumulative constraint on the existence of IMBHs in NSCs. Studying how the properties of the infalling clusters map to the properties of the resulting NSC, we find that, in the IMBHs-free case, the infall mechanism is able to produce many different observational signatures in the form of age segregation.