Skip to main content

Research Repository

Advanced Search

Outputs (36)

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.

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.

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.

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.

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.

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.

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.

Ephemeral networks with random availability of links: The case of fast networks (2015)
Journal Article
Akrida, E., Gąsieniec, L., Mertzios, G., & Spirakis, P. (2016). Ephemeral networks with random availability of links: The case of fast networks. Journal of Parallel and Distributed Computing, 87, 109-120. https://doi.org/10.1016/j.jpdc.2015.10.002

We consider here a model of temporal networks, the links of which are available only at certain moments in time, chosen randomly from a subset of the positive integers. We define the notion of the Temporal Diameter of such networks. We also define fa... Read More about Ephemeral networks with random availability of links: The case of fast networks.

Utilising Data-driven Learning in Chemistry Teaching: a Shortcut to Improving Chemical Language Comprehension (2014)
Journal Article
Rees, S., Bruce, M., & Bradley, S. (2014). Utilising Data-driven Learning in Chemistry Teaching: a Shortcut to Improving Chemical Language Comprehension. New Directions in the Teaching of Physical Sciences, 10(1), 12-19. https://doi.org/10.11120/ndir.2014.00028

This article describes the development of the FOCUS project and specific pedagogical strategies to improve understanding of the language of chemistry. The importance of language comprehension skills for success in learning chemistry has recently been... Read More about Utilising Data-driven Learning in Chemistry Teaching: a Shortcut to Improving Chemical Language Comprehension.

The ethical and social implications of personalization technologies for e-learning (2014)
Journal Article
Ashman, H., Brailsford, T., Cristea, A., Sheng, Q. Z., Stewart, C., Toms, E. G., & Wade, V. (2014). The ethical and social implications of personalization technologies for e-learning. Information and Management, 51(6), 819-832. https://doi.org/10.1016/j.im.2014.04.003

Personalization in information systems can be considered beneficial but also ethically and socially harmful. Like many other technologies, the uptake of personalization has been rapid, with inadequate consideration given to its effects. Personalizati... Read More about The ethical and social implications of personalization technologies for e-learning.