A Quantum of Learning: Using Quaternion Algebra to Model Learning on Quantum Devices

This article considers the problem of designing adaption and optimisation techniques for training quantum learning machines. To this end, the division algebra of quaternions is used to derive an effective model for representing computation and measurement operations on qubits. In turn, the derived model, serves as the foundation for formulating an adaptive learning problem on principal quantum learning units, thereby establishing quantum information processing units akin to that of neurons in classical approaches. Then, leveraging the modern HR-calculus, a comprehensive training framework for learning on quantum machines is developed. The quaternion-valued model accommodates mathematical tractability and establishment of performance criteria, such as convergence conditions

Similarities and Differences between Terrorists and their Supporters:Findings from Northern Ireland

Why do only a few people radicalise when many appear to have been exposed to potential causes of radicalisation? This issue is referred to as the specificity problem and is widely recognised as one of the fundamental questions facing terrorism research. Also recognised is that meaningful answers will only be obtained through comparative research using control groups who share many of the same traits, characteristics and contexts of the terrorists, but who did not progress to involvement in terrorism. The current study was conducted in Northern Ireland and compares 17 former paramilitary members with a control group of 12 paramilitary sympathizers using a structured survey. 22 variables connected to radicalisation were examined. Significant differences were found between the two groups on four of these variables. The findings are discussed in relation to the specificity problem and the wider literature on radicalisation

Subsets of free groups with distinct differences

Let F_n be a free group of rank n, with free generating set X. A subset D of F_n is a Distinct Difference Configuration if the differences g^{-1}h are distinct, where g and h range over all (ordered) pairs of distinct elements of D. The subset D has diameter at most d if these differences all have word length at most d. When n is fixed and d is large, the paper shows that the largest distinct difference configuration in F_n of diameter at most d has size approximately (2n-1)^{d/3}.<br/

Top Friends: Probing Higgs boson associated production with top quarks using the ATLAS detector

The Standard Model (SM) of particle physics represents the leading theoretical framework describing fundamental particles and their interactions. The generation of particle masses is explained via the Brout-Englert-Higgs mechanism, which introduces spontaneous symmetry breaking in the electroweak sector and predicts the existence of a scalar boson, known as the Higgs Boson. The Higgs Boson was experimentally confirmed by both the ATLAS and CMS collaborations at the Large Hadron Collider (LHC), CERN in 2012. The exploration of the Higgs Boson's properties, in particular its interactions with fermions, constitutes a pivotal aspect of the post-Higgs discovery era at the LHC. Among these, measuring Higgs production in association with a pair of top quarks ($t\bar{t}H$) offers a unique window into the Higgs-top-Yukawa coupling, the largest predicted Yukawa coupling in the SM. Precise measurements of $t\bar{t}H$ are required to either validate the SM prediction or highlight deviations hinting at possible new physics. This thesis presents a measurement of the $t\bar{t}H$ production cross-section in the $H\rightarrow b\bar{b}$ decay channel. The analysis is performed using 140~\text{fb}^{-1}}~of proton-proton collision data at a centre of mass energy of $\sqrt{s}=13$ TeV, collected with the ATLAS detector between 2015--2018 at the LHC, corresponding to the full Run 2 dataset. The analysis focuses on events with one or two light charged-leptons in the final state. The development and validation of the profile likelihood fit used to extract the signal cross-section is presented. Neural networks employing attention mechanisms and permutation invariant architectures, known as transformers, perform event classification and reconstruction. Network decisions and potential domain bias levels are studied and presented alongside studies to select the optimal set of observables for the profile likelihood fit. Events in excess of the background-only hypothesis are found, equivalent to an observed (expected) discovery significance of 4.6 (5.4) standard deviations, with a measured cross-section of \sigma_{\ttH} = 411^{+101}_{-92}~\fb = 411 \pm 54~\text{(stat.)}~^{+85}_{-75}~\text{(syst.)} \text{fb}\ ,the most precise individual measurement of $t\bar{t}H$ production to date. The measurement agrees with the SM prediction. Differential cross-section measurements with respect to the Higgs Boson transverse momentum are also performed within the simplified template cross-section framework. The analysis provides critical precision in the high $p_{T}^{H}$ regime for future combination and Effective field theory (EFT) interpretations

Goal Legibility and Recognition for Anonymous Multi-Agent Pathfinding Systems:A Graph Theoretical Approach

Goal legibility, one of the dimensions of agent interpretability, has gained significant attention in human-machine interaction research. This thesis explores goal legibility in relation to goal recognition in a multi-agent setting with an observer-in-the-loop. Specifically, it considers an environment where identical agents move from an origin to designated destinations, and an observer monitors their movements, aiming to infer their destinations as quickly as possible. Our approach generates legible paths that minimize overlap while satisfying budget constraints. We also developed a goal recognition framework that maps observation sequences to specific destinations, enabling the observer to infer an agent's goal with minimal (legibility) delay. The legible path planning problem is reformulated as a classical network flow problem for fully observable scenarios, using combinatorial optimization tools to create scalable algorithms. The method adapts efficiently to partially observable settings as well. While effective, these techniques can become computationally demanding. To address this, we introduced initial goal legibility, where the observer begins monitoring agents from their entry point. This variant focuses on inferring destinations by observing initial trajectories. Through mathematical reformulations, our approach computes paths that minimize trajectory overlap, and agents then follow optimal routes. This method is applicable to both fully and partially observable environments. Empirical evaluations demonstrate the scalability and efficiency of our techniques, confirming their practical relevance

Finanzieller Missbrauch älterer Menschen:Strategien der Befähigung

(translated abstract)In October 2018, a UK Member of Parliament, Giles Watling, used his maiden speech to highlight the issue of elder abuse in the UK. Although imperfectly and inconsistently defined, elder abuse is commonly referred to as “a single or repeated act, or lack of appropriate action, occurring within any relationship where there is an expectation of trust” which results in “harm or distress” to an older person. It is, Watling noted, a widespread yet “poorly understood” crime which deserves to dominate political discourse but which is too often overlooked, the result being Parliament’s “marginalising [of] a forgotten generation.” Elder abuse is also a human rights violation, with the Equality and Human Rights Commission and All Parliamentary Group on Aging and Older People respectively identifying “serious” and “systemic” threats to the human rights of older people as a result. The UK House of Commons Health Committee reported on elder abuse in 2004, expressing concern at the “refusal of professional bodies and society overall to acknowledge the extent of the problem”. Importantly, in Europe and worldwide, states have been slow to respond to elder financial abuse, which is perceived as an increasingly pressing issue

The phonological store of working memory:A critique and an alternative, perceptual-motor, approach to verbal short-term memory

A key quality of a good theory is its fruitfulness, one measure of which might be the degree to which it compels researchers to test it, refine it, or offer alternative explanations of the same empirical data. Perhaps the most fruitful element of Baddeley and Hitch’s (1974) Working Memory framework has been the concept of a short-term phonological store, a discrete cognitive module dedicated to the passive storage of verbal material that is architecturally fractionated from perceptual, language, and articulatory systems. This review discusses how the phonological store construct has served as the main theoretical springboard for an alternative perceptual-motor approach in which serial recall performance reflects the opportunistic co-opting of the articulatory planning system and, when auditory material is involved, the products of obligatory auditory perceptual organisation. It is argued that this approach, which rejects the need to posit a distinct short-term store, provides a better account of the two putative empirical hallmarks of the phonological store—the phonological similarity effect and the irrelevant speech effect—and that it shows promise too in being able to account for nonword repetition and word-form learning, the supposed evolved function of the phonological store. The neuropsychological literature cited as strong additional support for the phonological store concept is also scrutinised through the lens of the perceptual-motor approach for the first time and a tentative articulatory-planning deficit hypothesis for the ‘short-term memory’ patient profile is advanced. Finally, the relation of the perceptual-motor approach to other ‘emergent-property’ accounts of short-term memory is briefly considered

The Role of Self-as-Context as a Self-Based Process of Change in Cancer-Related Pain:Insights from a Network Analysis

Background/Objectives: The dual burden of cancer and pain during chemotherapy can negatively impact individuals’ personal integrity, or the “self”. Yet, coping strategies addressing these dual challenges are rarely employed in cancer-related pain management. Recent findings from evidence-based behavioral models, such as psychological flexibility in pain, highlight the potential role of self-as-context (SAC) as a central coping strategy for adjustment. The aim of this study was to examine the network structure of “conventional” coping strategies, such as active coping, behavioral disengagement, substance use, seeking support, religion, humor, and avoidance (Brief-COPE-8 coping strategies), in relation to “self-based” coping strategies. Methods: Individuals diagnosed with cancer, mostly in advanced stages (i.e., II and III), experiencing cancer-related pain (n = 135), completed a cross-sectional online study. Participants filled out self-reported questionnaires, including the Brief-COPE, the Psychological Inflexibility in Pain Scale—Greek Version (G-PIPS-II), and the Self-as-Context Scale (SACS) scale, which included two subfactors: centering and transcending. The study employed a stepwise analysis plan. We first conducted a series of traditional correlations, analysis of variance (ANOVA), and hierarchical multiple linear regressions, to examine the predictive role of demographics/clinical characteristics, psychological inflexibility, and SAC (independent variables) on the eight coping strategies (dependent variables). We then selected the highest predictors of coping in cancer-related pain and included them in a network analysis model. In the network analysis, we estimated the LASSO network regularization and examined network stability. We also assessed the centrality and stability of the network model, focusing on the associations between SAC items, the most predictive coping strategies (Brief-COPE), and psychological inflexibility (G-PIPS-II). Results: SAC correlated positively with effective coping (active coping and humor) and negatively with substance use. There were no correlations between demographics, type, stage of cancer, and coping strategies for pain. Multiple linear regressions identified psychological inflexibility and SAC as the main contributors to pain adjustment, with SAC explaining substantially more variance in active coping. The partial correlation network included 12 nodes. Active coping, centering, and three of the six transcending items were the most influential in the network. Active coping demonstrated the highest centrality, exerting positive links with SAC items that reflected calm reactions and invariant perspective-taking in response to the pain experience. Conclusions: SAC might be considered as a tailored, self-based coping strategy for managing cancer-related pain. Future analog studies should explore the role of integrating self-based perspective-taking strategies to momentarily address cancer-related pain