University College Dublin

About: University College Dublin is a education organization based out in Dublin, Dublin, Ireland. It is known for research contribution in the topics: Population & Context (language use). The organization has 22895 authors who have published 55318 publications receiving 1759686 citations. The organization is also known as: University College Dublin – National University of Ireland, Dublin & National University of Ireland, Dublin - University College Dublin.

Improvements to core-guided binary search for MaxSAT

Abstract: Maximum Satisfiability (MaxSAT) and its weighted variants are well-known optimization formulations of Boolean Satisfiability (SAT). Motivated by practical applications, recent years have seen the development of core-guided algorithms for MaxSAT. Among these, core-guided binary search with disjoint cores (BCD) represents a recent robust solution. This paper identifies a number of inefficiencies in the original BCD algorithm, related with the computation of lower and upper bounds during the execution of the algorithm, and develops solutions for them. In addition, the paper proposes two additional novel techniques, which can be implemented on top of core-guided MaxSAT algorithms that maintain both lower and upper bounds. Experimental results, obtained on representative problem instances, indicate that the proposed optimizations yield significant performance gains, and allow solving more problem instances.

Semantically enriching VGI in support of implicit feedback analysis

Abstract: In recent years, the proliferation of Volunteered Geographic Information (VGI) has enabled many Internet users to contribute to the construction of rich and increasingly complex spatial datasets. This growth of geo-referenced information and the often loose semantic structure of such data have resulted in spatial information overload. For this reason, a semantic gap has emerged between unstructured geo-spatial datasets and high-level ontological concepts. Filling this semantic gap can help reduce spatial information overload, therefore facilitating both user interactions and the analysis of such interaction. Implicit Feedback analysis is the focus of our work. In this paper we address this problem by proposing a system that executes spatial discovery queries. Our system combines a semantically-rich and spatially-poor ontology (DBpedia) with a spatially-rich and semantically-poor VGI dataset (OpenStreetMap). This technique differs from existing ones, such as the aggregated dataset LinkedGeoData, as it is focused on user interest analysis and takes map scale into account. System architecture, functionality and preliminary results gathered about the system performance are discussed.

Post-lockdown abatement of COVID-19 by fast periodic switching.

Abstract: COVID-19 abatement strategies have risks and uncertainties which could lead to repeating waves of infection. We show-as proof of concept grounded on rigorous mathematical evidence-that periodic, high-frequency alternation of into, and out-of, lockdown effectively mitigates second-wave effects, while allowing continued, albeit reduced, economic activity. Periodicity confers (i) predictability, which is essential for economic sustainability, and (ii) robustness, since lockdown periods are not activated by uncertain measurements over short time scales. In turn-while not eliminating the virus-this fast switching policy is sustainable over time, and it mitigates the infection until a vaccine or treatment becomes available, while alleviating the social costs associated with long lockdowns. Typically, the policy might be in the form of 1-day of work followed by 6-days of lockdown every week (or perhaps 2 days working, 5 days off) and it can be modified at a slow-rate based on measurements filtered over longer time scales. Our results highlight the potential efficacy of high frequency switching interventions in post lockdown mitigation. All code is available on Github at https://github.com/V4p1d/FPSP_Covid19. A software tool has also been developed so that interested parties can explore the proof-of-concept system.

The development and questing activity of Ixodes ricinus (L.) (Acari: Ixodidae) under field conditions in Ireland

Abstract: Development rates of engorged examples of Ixodes ricinus (L.) and the onset and duration of questing activity of unfed ticks were investigated in gauze cages in the field in the Irish Republic. Development rates of the various stages were broadly similar to those described in other studies but differed in small detail from most of them. It was found that larvae that fed during or after the first two weeks of August entered diapause. The activity periods of questing ticks were found to agree closely with observations made in the field, and the origins of the various peaks in tick activity in the field were thus elucidated. It was established that considerable interchange between autumn-feeding and spring-feeding populations of ticks can occur, and it is concluded that the extent of this is largely controlled by the weather, being accentuated by high summer temperatures.