Outputs (43)

Evaluating Gaussian Grasp Maps for Generative Grasping Models (2022)
Presentation / Conference Contribution
Prew, W., Breckon, T., Bordewich, M., & Beierholm, U. (2022, July). Evaluating Gaussian Grasp Maps for Generative Grasping Models. Presented at Proc. Int. Joint Conf. Neural Networks, Padova, Italy

Generalising robotic grasping to previously unseen objects is a key task in general robotic manipulation. The current method for training many antipodal generative grasping models rely on a binary ground truth grasp map generated from the centre thir... Read More about Evaluating Gaussian Grasp Maps for Generative Grasping Models.

On the Complexity of Optimising Variants of Phylogenetic Diversity on Phylogenetic Networks (2022)
Journal Article
Bordewich, M., Semple, C., & Wicke, K. (2022). On the Complexity of Optimising Variants of Phylogenetic Diversity on Phylogenetic Networks. Theoretical Computer Science, 917, 66-80. https://doi.org/10.1016/j.tcs.2022.03.012

Phylogenetic Diversity (PD) is a prominent quantitative measure of the biodiversity of a collection of present-day species (taxa). This measure is based on the evolutionary distance among the species in the collection. Loosely speaking, if T is a roo... Read More about On the Complexity of Optimising Variants of Phylogenetic Diversity on Phylogenetic Networks.

On the Maximum Agreement Subtree Conjecture for Balanced Trees (2022)
Journal Article
Bordewich, M., Linz, S., Owen, M., St. John, K., Semple, C., & Wicke, K. (2022). On the Maximum Agreement Subtree Conjecture for Balanced Trees. SIAM Journal on Discrete Mathematics, 36(1), 336-354. https://doi.org/10.1137/20m1379678

We give a counterexample to the conjecture of Martin and Thatte that two balanced rooted binary leaf-labelled trees on n leaves have a maximum agreement subtree (MAST) of size at least n 1 2 . In particular, we show that for any c > 0, there exist tw... Read More about On the Maximum Agreement Subtree Conjecture for Balanced Trees.

Autoencoders Without Reconstruction for Textural Anomaly Detection (2021)
Presentation / Conference Contribution
Adey, P., Akcay, S., Bordewich, M., & Breckon, T. (2021, July). Autoencoders Without Reconstruction for Textural Anomaly Detection. Presented at 2021 International Joint Conference on Neural Networks (IJCNN), Shenzhen, China

Automatic anomaly detection in natural textures is a key component within quality control for a range of high-speed, high-yield manufacturing industries that rely on camera-based visual inspection techniques. Targeting anomaly detection through the u... Read More about Autoencoders Without Reconstruction for Textural Anomaly Detection.

Improving Robotic Grasping on Monocular Images Via Multi-Task Learning and Positional Loss (2021)
Presentation / Conference Contribution
Prew, W., Breckon, T., Bordewich, M., & Beierholm, U. (2021, January). Improving Robotic Grasping on Monocular Images Via Multi-Task Learning and Positional Loss. Presented at 25th International Conference on Pattern Recognition (ICPR 2020), Milan, Italy

In this paper we introduce two methods of improving real-time object grasping performance from monocular colour images in an end-to-end CNN architecture. The first is the addition of an auxiliary task during model training (multi-task learning). Our... Read More about Improving Robotic Grasping on Monocular Images Via Multi-Task Learning and Positional Loss.

A universal tree-based network with the minimum number of reticulations (2018)
Journal Article
Bordewich, M., & Semple, C. (2018). A universal tree-based network with the minimum number of reticulations. Discrete Applied Mathematics, 250, 357-362. https://doi.org/10.1016/j.dam.2018.05.010

A tree-based network N on X is universal if every rooted binary phylogenetic X-tree is a base tree for N. Hayamizu and, independently, Zhang constructively showed that, for all positive integers n, there exists an universal tree-based network on n le... Read More about A universal tree-based network with the minimum number of reticulations.

Recovering normal networks from shortest inter-taxa distance information (2018)
Journal Article
Bordewich, M., Huber, K. T., Moulton, V., & Semple, C. (2018). Recovering normal networks from shortest inter-taxa distance information. Journal of Mathematical Biology, 77(3), 571-594. https://doi.org/10.1007/s00285-018-1218-x

Phylogenetic networks are a type of leaf-labelled, acyclic, directed graph used by biologists to represent the evolutionary history of species whose past includes reticulation events. A phylogenetic network is tree–child if each non-leaf vertex is th... Read More about Recovering normal networks from shortest inter-taxa distance information.

On the information content of discrete phylogenetic characters (2017)
Journal Article
Bordewich, M., Deutschmann, I. M., Fischer, M., Kasbohm, E., Semple, C., & Steel, M. (2018). On the information content of discrete phylogenetic characters. Journal of Mathematical Biology, 77(3), 527-544. https://doi.org/10.1007/s00285-017-1198-2

Phylogenetic inference aims to reconstruct the evolutionary relationships of different species based on genetic (or other) data. Discrete characters are a particular type of data, which contain information on how the species should be grouped togethe... Read More about On the information content of discrete phylogenetic characters.

Constructing Tree-Child Networks from Distance Matrices (2017)
Journal Article
Bordewich, M., Semple, C., & Tokac, N. (2017). Constructing Tree-Child Networks from Distance Matrices. Algorithmica, 80(8), 2240-2259. https://doi.org/10.1007/s00453-017-0320-6

A tree-child network is a phylogenetic network with the property that each non-leaf vertex is the parent of a tree vertex or a leaf. In this paper, we show that a tree-child network on taxa (leaf) set X with an outgroup and a positive real-valued wei... Read More about Constructing Tree-Child Networks from Distance Matrices.

Lost in space? Generalising subtree prune and regraft to spaces of phylogenetic networks (2017)
Journal Article
Bordewich, M., Linz, S., & Semple, C. (2017). Lost in space? Generalising subtree prune and regraft to spaces of phylogenetic networks. Journal of Theoretical Biology, 423, 1-12. https://doi.org/10.1016/j.jtbi.2017.03.032

Over the last fifteen years, phylogenetic networks have become a popular tool to analyse relationships between species whose past includes reticulation events such as hybridisation or horizontal gene transfer. However, the space of phylogenetic netwo... Read More about Lost in space? Generalising subtree prune and regraft to spaces of phylogenetic networks.

An algorithm for reconstructing ultrametric tree-child networks from inter-taxa distances (2016)
Journal Article
Bordewich, M., & Tokac, N. (2016). An algorithm for reconstructing ultrametric tree-child networks from inter-taxa distances. Discrete Applied Mathematics, 213, 47-59. https://doi.org/10.1016/j.dam.2016.05.011

Traditional “distance based methods” reconstruct a phylogenetic tree from a matrix of pair-wise distances between taxa. A phylogenetic network is a generalisation of a phylogenetic tree that can describe evolutionary events such as reticulation and h... Read More about An algorithm for reconstructing ultrametric tree-child networks from inter-taxa distances.

On the Fixed Parameter Tractability of Agreement-based Phylogenetic Distances (2016)
Journal Article
Bordewich, M., Scornavacca, C., Tokac, N., & Weller, M. (2017). On the Fixed Parameter Tractability of Agreement-based Phylogenetic Distances. Journal of Mathematical Biology, 74(1), 239-257. https://doi.org/10.1007/s00285-016-1023-3

Three important and related measures for summarizing the dissimilarity in phylogenetic trees are the minimum number of hybridization events required to fit two phylogenetic trees onto a single phylogenetic network (the hybridization number), the (roo... Read More about On the Fixed Parameter Tractability of Agreement-based Phylogenetic Distances.

Reticulation-Visible Networks (2016)
Journal Article
Bordewich, M., & Semple, C. (2016). Reticulation-Visible Networks. Advances in Applied Mathematics, 78, 114-141. https://doi.org/10.1016/j.aam.2016.04.004

Let X be a finite set, N be a reticulation-visible network on X , and T be a rooted binary phylogenetic tree. We show that there is a polynomial-time algorithm for deciding whether or not N displays T. Furthermore, for all |X|≥1, we show that N has a... Read More about Reticulation-Visible Networks.

Determining phylogenetic networks from inter-taxa distances (2015)
Journal Article
Bordewich, M., & Semple, C. (2016). Determining phylogenetic networks from inter-taxa distances. Journal of Mathematical Biology, 73(2), 283-303. https://doi.org/10.1007/s00285-015-0950-8

We consider the problem of determining the topological structure of a phylogenetic network given only information about the path-length distances between taxa. In particular, one of the main results of the paper shows that binary tree-child networks... Read More about Determining phylogenetic networks from inter-taxa distances.

Defining a Phylogenetic Tree with the Minimum Number of r-State Characters (2015)
Journal Article
Bordewich, M., & Semple, C. (2015). Defining a Phylogenetic Tree with the Minimum Number of r-State Characters. SIAM Journal on Discrete Mathematics, 29(2), 835-853. https://doi.org/10.1137/130924469

Semple and Steel (2002) showed that if T is a phylogenetic X-tree and C is a collection of r-state characters that defines T , then |C| ≥ (n − 3)/(r − 1), where n = |X|. In this paper, we show that, provided n is sufficiently large, this lower bound... Read More about Defining a Phylogenetic Tree with the Minimum Number of r-State Characters.

Subset Glauber Dynamics on Graphs, Hypergraphs and Matroids of Bounded Tree-Width (2014)
Journal Article
Bordewich, M., & Kang, R. (2014). Subset Glauber Dynamics on Graphs, Hypergraphs and Matroids of Bounded Tree-Width. Electronic Journal of Combinatorics, 21(4), Article 19

Motivated by the `subgraphs world' view of the ferromagnetic Ising model, we analyse the mixing times of Glauber dynamics based on subset expansion expressions for classes of graph, hypergraph and matroid polynomials. With a canonical paths argument,... Read More about Subset Glauber Dynamics on Graphs, Hypergraphs and Matroids of Bounded Tree-Width.

Mixing of the Glauber Dynamics for the Ferromagnetic Potts Model (2014)
Journal Article
Bordewich, M., Greenhill, C., & Patel, V. (2016). Mixing of the Glauber Dynamics for the Ferromagnetic Potts Model. Random Structures and Algorithms, 48(1), 21-52. https://doi.org/10.1002/rsa.20569

We present several results on the mixing time of the Glauber dynamics for sampling from the Gibbs distribution in the ferromagnetic Potts model. At a fixed temperature and interaction strength, we study the interplay between the maximum degree (Δ) of... Read More about Mixing of the Glauber Dynamics for the Ferromagnetic Potts Model.

Accuracy Guarantees for Phylogeny Reconstruction Algorithms Based on Balanced Minimum Evolution (2013)
Journal Article
Bordewich, M., & Mihaescu, R. (2013). Accuracy Guarantees for Phylogeny Reconstruction Algorithms Based on Balanced Minimum Evolution. IEEE/ACM Transactions on Computational Biology and Bioinformatics, 10(3), 576-583. https://doi.org/10.1109/tcbb.2013.39

Distance-based phylogenetic methods attempt to reconstruct an accurate phylogenetic tree from an estimated matrix of pairwise distances between taxa. This paper examines two distance-based algorithms (GREEDYBME and FASTME) that are based on the princ... Read More about Accuracy Guarantees for Phylogeny Reconstruction Algorithms Based on Balanced Minimum Evolution.

Budgeted Nature Reserve Selection with diversity feature loss and arbitrary split systems (2012)
Journal Article
Bordewich, M., & Semple, C. (2012). Budgeted Nature Reserve Selection with diversity feature loss and arbitrary split systems. Journal of Mathematical Biology, 64(1), 69-85. https://doi.org/10.1007/s00285-011-0405-9

Arising in the context of biodiversity conservation, the Budgeted Nature Reserve Selection (BNRS) problem is to select, subject to budgetary constraints, a set of regions to conserve so that the phylogenetic diversity (PD) of the set of species conta... Read More about Budgeted Nature Reserve Selection with diversity feature loss and arbitrary split systems.

On the approximation complexity hierarchy. (2011)
Presentation / Conference Contribution
Bordewich, M. (2010, September). On the approximation complexity hierarchy. Presented at 8th International Workshop on International Workshop on Approximation and Online Algorithms, WAOA 2010, Liverpool

This paper presents an extension of Ladner’s Theorem to the approximation complexity hierarchy. In 1975 Ladner proved that if P≠NP, then there exists an incomplete problem A which is neither in P nor NP-complete. Here we show that if RP≠NP, then ther... Read More about On the approximation complexity hierarchy..