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Outputs (111)

The engage taxonomy: SDT-based measurable engagement indicators for MOOCs and their evaluation (2023)
Journal Article
Cristea, A. I., Alamri, A., Alshehri, M., Dwan Pereira, F., Toda, A. M., Harada T. de Oliveira, E., & Stewart, C. (2024). The engage taxonomy: SDT-based measurable engagement indicators for MOOCs and their evaluation. User Modeling and User-Adapted Interaction, 34(2), 323-374. https://doi.org/10.1007/s11257-023-09374-x

Massive Online Open Course (MOOC) platforms are considered a distinctive way to deliver a modern educational experience, open to a worldwide public. However, student engagement in MOOCs is a less explored area, although it is known that MOOCs suffer... Read More about The engage taxonomy: SDT-based measurable engagement indicators for MOOCs and their evaluation.

Computing Education Research in the UK & Ireland (2023)
Book Chapter
Becker, B. A., Bradley, S., Maguire, J., Black, M., Crick, T., Saqr, M., …Quille, K. (2023). Computing Education Research in the UK & Ireland. In M. Apiola, S. López-Pernas, & M. Saqr (Eds.), Past, Present and Future of Computing Education Research (421-479). Springer Verlag. https://doi.org/10.1007/978-3-031-25336-2_19

In 1970, SIGCSE had five members from England, Scotland and Wales. By 1983 Ireland had a member, followed by Northern Ireland in 1995. Well before then researchers from these countries had contributed to the growing CER community. In 1998 the 3rd ACM... Read More about Computing Education Research in the UK & Ireland.

Large-scale mammal monitoring: the potential of a citizen science camera-trapping project in the United Kingdom (2022)
Journal Article
Hsing, P., Hill, R., Smith, G., Bradley, S., Green, S., Kent, V., …Stephens, P. (2022). Large-scale mammal monitoring: the potential of a citizen science camera-trapping project in the United Kingdom. Ecological Solutions and Evidence, 3(4), Article e12180. https://doi.org/10.1002/2688-8319.12180

1. In light of global biodiversity loss, there is an increasing need for large-scale wildlife monitoring. This is difficult for mammals, since they can be elusive and nocturnal. In the United Kingdom (UK), there is a lack of systematic, widespread ma... Read More about Large-scale mammal monitoring: the potential of a citizen science camera-trapping project in the United Kingdom.

ExBERT: An External Knowledge Enhanced BERT for Natural Language Inference (2021)
Book Chapter
Gajbhiye, A., Al Moubayed, N., & Bradley, S. (2021). ExBERT: An External Knowledge Enhanced BERT for Natural Language Inference. In I. Farkaš, P. Masulli, S. Otte, & S. Wermter (Eds.), Artificial Neural Networks and Machine Learning – ICANN 2021 30th International Conference on Artificial Neural Networks, Bratislava, Slovakia, September 14–17, 2021, Proceedings, Part V (460-472). Springer Verlag. https://doi.org/10.1007/978-3-030-86383-8_37

Neural language representation models such as BERT, pretrained on large-scale unstructured corpora lack explicit grounding to real-world commonsense knowledge and are often unable to remember facts required for reasoning and inference. Natural Langua... Read More about ExBERT: An External Knowledge Enhanced BERT for Natural Language Inference.

Connected Subgraph Defense Games (2021)
Journal Article
Akrida, E. C., Deligkas, A., Melissourgos, T., & Spirakis, P. G. (2021). Connected Subgraph Defense Games. Algorithmica, 83(11), 3403-3431. https://doi.org/10.1007/s00453-021-00858-z

We study a security game over a network played between a defender and k attackers. Every attacker chooses, probabilistically, a node of the network to damage. The defender chooses, probabilistically as well, a connected induced subgraph of the networ... Read More about Connected Subgraph Defense Games.

MOOC next week dropout prediction: weekly assessing time and learning patterns (2021)
Book Chapter
Alamri, A., Sun, Z., Cristea, A. I., Steward, C., & Pereira, F. D. (2021). MOOC next week dropout prediction: weekly assessing time and learning patterns. In A. I. Cristea, & C. Troussas (Eds.), Intelligent Tutoring Systems: 17th International Conference, ITS 2021, Virtual Event, June 7–11, 2021, Proceedings (119-130). Springer Verlag. https://doi.org/10.1007/978-3-030-80421-3_15

Although Massive Open Online Course (MOOC) systems have become more prevalent in recent years, associated student attrition rates are still a major drawback. In the past decade, many researchers have sought to explore the reasons behind learner attri... Read More about MOOC next week dropout prediction: weekly assessing time and learning patterns.

The temporal explorer who returns to the base (2021)
Journal Article
Akrida, E., Mertzios, G., Spirakis, P., & Raptopoulos, C. (2021). The temporal explorer who returns to the base. Journal of Computer and System Sciences, 120, 179-193. https://doi.org/10.1016/j.jcss.2021.04.001

We study here the problem of exploring a temporal graph when the underlying graph is a star. The aim of the exploration problem in a temporal star is finding a temporal walk which starts and finishes at the center of the star, and visits all leaves.... Read More about The temporal explorer who returns to the base.

Towards Designing Profitable Courses: Predicting Student Purchasing Behaviour in MOOCs (2021)
Journal Article
Alshehri, M., Alamri, A., Cristea, A. I., & Stewart, C. D. (2021). Towards Designing Profitable Courses: Predicting Student Purchasing Behaviour in MOOCs. International Journal of Artificial Intelligence in Education, 31(2), 215-233. https://doi.org/10.1007/s40593-021-00246-2

Since their ‘official’ emergence in 2012 (Gardner and Brooks 2018), massive open online courses (MOOCs) have been growing rapidly. They offer low-cost education for both students and content providers; however, currently there is a very low level of... Read More about Towards Designing Profitable Courses: Predicting Student Purchasing Behaviour in MOOCs.

Bilinear Fusion of Commonsense Knowledge with Attention-Based NLI Models (2020)
Book Chapter
Gajbhiye, A., Winterbottom, T., Al Moubayed, N., & Bradley, S. (2020). Bilinear Fusion of Commonsense Knowledge with Attention-Based NLI Models. In I. Farkaš, P. Masulli, & S. Wermter (Eds.), Artificial Neural Networks and Machine Learning – ICANN 2020 (633-646). Springer Verlag. https://doi.org/10.1007/978-3-030-61609-0_50

We consider the task of incorporating real-world commonsense knowledge into deep Natural Language Inference (NLI) models. Existing external knowledge incorporation methods are limited to lexical-level knowledge and lack generalization across NLI mode... Read More about Bilinear Fusion of Commonsense Knowledge with Attention-Based NLI Models.

How fast can we reach a target vertex in stochastic temporal graphs? (2020)
Journal Article
Akrida, E. C., Mertzios, G. B., Nikoletseas, S., Raptopoulos, C., Spirakis, P. G., & Zmaraev, V. (2020). How fast can we reach a target vertex in stochastic temporal graphs?. Journal of Computer and System Sciences, 114, 65-83. https://doi.org/10.1016/j.jcss.2020.05.005

Temporal graphs abstractly model real-life inherently dynamic networks. Given a graph G, a temporal graph with G as the underlying graph is a sequence of subgraphs (snapshots) of G, where . In this paper we study stochastic temporal graphs, i.e. stoc... Read More about How fast can we reach a target vertex in stochastic temporal graphs?.

Citizen scientists: school students conducting, contributing to and communicating ecological research – experiences of a school–university partnership (2020)
Journal Article
Hsing, P., Coghill, L., Ryder, J., Austin, M., Dooley, S., Ellison, A., …Stephens, P. (2020). Citizen scientists: school students conducting, contributing to and communicating ecological research – experiences of a school–university partnership. School science review, 101(376), 67-74

Started in north-east England in 2015, MammalWeb aims to improve our knowledge of British mammals through the use of motion-sensing camera traps. Fundamental to the project is the involvement of local communities and individuals who act as citizen sc... Read More about Citizen scientists: school students conducting, contributing to and communicating ecological research – experiences of a school–university partnership.

Connected Subgraph Defense Games (2019)
Book Chapter
Akrida, E. C., Deligkas, A., Melissourgos, T., & Spirakis, P. G. (2019). Connected Subgraph Defense Games. In Algorithmic Game Theory (216-236). Springer Verlag. https://doi.org/10.1007/978-3-030-30473-7_15

We study a security game over a network played between a defender and k attackers. Every attacker chooses, probabilistically, a node of the network to damage. The defender chooses, probabilistically as well, a connected induced subgraph of the networ... Read More about Connected Subgraph Defense Games.

Temporal vertex cover with a sliding time window (2019)
Journal Article
Akrida, E., Mertzios, G., Spirakis, P., & Zamaraev, V. (2020). Temporal vertex cover with a sliding time window. Journal of Computer and System Sciences, 107, 108-123. https://doi.org/10.1016/j.jcss.2019.08.002

Modern, inherently dynamic systems are usually characterized by a network structure which is subject to discrete changes over time. Given a static underlying graph, a temporal graph can be represented via an assignment of a set of integer time-labels... Read More about Temporal vertex cover with a sliding time window.

On Verifying and Maintaining Connectivity of Interval Temporal Networks (2019)
Journal Article
Akrida, E. C., & Spirakis, P. G. (2019). On Verifying and Maintaining Connectivity of Interval Temporal Networks. Parallel Processing Letters, 29(02), Article 1950009. https://doi.org/10.1142/s0129626419500099

An interval temporal network is, informally speaking, a network whose links change with time. The term interval means that a link may exist for one or more time intervals, called availability intervals of the link, after which it does not exist (unti... Read More about On Verifying and Maintaining Connectivity of Interval Temporal Networks.

Predicting MOOCs Dropout Using Only Two Easily Obtainable Features from the First Week’s Activities (2019)
Book Chapter
Alamri, A., Alshehri, M., Cristea, A. I., Pereira, F. D., Oliveira, E., Shi, L., & Stewart, C. (2019). Predicting MOOCs Dropout Using Only Two Easily Obtainable Features from the First Week’s Activities. In A. Coy, Y. Hayashi, & M. Chang (Eds.), Intelligent tutoring systems. ITS 2019 (163-173). Springer Verlag. https://doi.org/10.1007/978-3-030-22244-4_20

While Massive Open Online Course (MOOCs) platforms provide knowledge in a new and unique way, the very high number of dropouts is a significant drawback. Several features are considered to contribute towards learner attrition or lack of interest, whi... Read More about Predicting MOOCs Dropout Using Only Two Easily Obtainable Features from the First Week’s Activities.

Temporal flows in temporal networks (2019)
Journal Article
Akrida, E. C., Czyzowicz, J., Gąsieniec, L., Kuszner, Ł., & Spirakis, P. G. (2019). Temporal flows in temporal networks. Journal of Computer and System Sciences, 103, 46-60. https://doi.org/10.1016/j.jcss.2019.02.003

We introduce temporal flows on temporal networks. We show that one can find the maximum amount of flow that can pass from a source vertex s to a sink vertex t up to a given time in Polynomial time. We provide a static Time-Extended network (TEG) of p... Read More about Temporal flows in temporal networks.

Economical crowdsourcing for camera trap image classification (2018)
Journal Article
Hsing, P., Bradley, S., Kent, V., Hill, R., Smith, G., Whittingham, M., …Stephens, P. (2018). Economical crowdsourcing for camera trap image classification. Remote Sensing in Ecology and Conservation, 4(4), 361-374. https://doi.org/10.1002/rse2.84

Camera trapping is widely used to monitor mammalian wildlife but creates large image datasets that must be classified. In response, there is a trend towards crowdsourcing image classification. For high‐profile studies of charismatic faunas, many clas... Read More about Economical crowdsourcing for camera trap image classification.

Binarisation for Valued Constraint Satisfaction Problems (2017)
Journal Article
Cohen, D., Cooper, M., Jeavons, P., Krokhin, A., Powell, R., & Zivny, S. (2017). Binarisation for Valued Constraint Satisfaction Problems. SIAM Journal on Discrete Mathematics, 31(4), 2279-2300. https://doi.org/10.1137/16m1088107

We study methods for transforming valued constraint satisfaction problems (VCSPs) to binary VCSPs. First, we show that the standard dual encoding preserves many aspects of the algebraic properties that capture the computational complexity of VCSPs. S... Read More about Binarisation for Valued Constraint Satisfaction Problems.

The complexity of optimal design of temporally connected graphs (2017)
Journal Article
Akrida, E., Gasieniec, L., Mertzios, G., & Spirakis, P. (2017). The complexity of optimal design of temporally connected graphs. Theory of Computing Systems, 61(3), 907-944. https://doi.org/10.1007/s00224-017-9757-x

We study the design of small cost temporally connected graphs, under various constraints. We mainly consider undirected graphs of n vertices, where each edge has an associated set of discrete availability instances (labels). A journey from vertex u t... Read More about The complexity of optimal design of temporally connected graphs.