Inflows towards active regions and the modulation of the solar cycle: a parameter study

Aims: We aim to investigate how converging flows towards active regions affect the surface transport of magnetic flux, as well as their impact on the generation of the Sun's poloidal field. The inflows constitute a potential non-linear mechanism for the saturation of the global dynamo and may contribute to the modulation of the solar cycle in the Babcock-Leighton framework. Methods: We build a surface flux transport code incorporating a parametrized model of the inflows and run simulations spanning several cycles. We carry out a parameter study to assess how the strength and extension of the inflows affect the build-up of the global dipole field. We also perform simulations with different levels of activity to investigate the potential role of the inflows in the saturation of the global dynamo. Results: We find that the interaction of neighbouring active regions can lead to the occasional formation of single-polarity magnetic flux clumps inconsistent with observations. We propose the darkening caused by pores in areas of high magnetic field strength as a plausible mechanism preventing this flux-clumping. We find that inflows decrease the amplitude of the axial dipole moment by a $\sim30\,\%$, relative to a no-inflows scenario. Stronger (weaker) inflows lead to larger (smaller) reductions of the axial dipole moment. The relative amplitude of the generated axial dipole is about $9\%$ larger after very weak cycles than after very strong cycles. This supports the inflows as a non-linear mechanism capable of saturating the global dynamo and contributing to the modulation of the solar cycle within the Babcock-Leighton framework

Surface flux transport simulations: Effect of inflows toward active regions and random velocities on the evolution of the Sun's large-scale magnetic field

Aims: We aim to determine the effect of converging flows on the evolution of a bipolar magnetic region (BMR), and to investigate the role of these inflows in the generation of poloidal flux. We also discuss whether the flux dispersal due to turbulent flows can be described as a diffusion process. Methods: We developed a simple surface flux transport model based on point-like magnetic concentrations. We tracked the tilt angle, the magnetic flux and the axial dipole moment of a BMR in simulations with and without inflows and compared the results. To test the diffusion approximation, simulations of random walk dispersal of magnetic features were compared against the predictions of the diffusion treatment. Results: We confirm the validity of the diffusion approximation to describe flux dispersal on large scales. We find that the inflows enhance flux cancellation, but at the same time affect the latitudinal separation of the polarities of the bipolar region. In most cases the latitudinal separation is limited by the inflows, resulting in a reduction of the axial dipole moment of the BMR. However, when the initial tilt angle of the BMR is small, the inflows produce an increase in latitudinal separation that leads to an increase in the axial dipole moment in spite of the enhanced flux destruction. This can give rise to a tilt of the BMR even when the BMR was originally aligned parallel to the equator

Uniformity in association schemes and coherent configurations: cometric Q-antipodal schemes and linked systems

Inspired by some intriguing examples, we study uniform association schemes and uniform coherent configurations, including cometric Q-antipodal association schemes. After a review of imprimitivity, we show that an imprimitive association scheme is uniform if and only if it is dismantlable, and we cast these schemes in the broader context of certain --- uniform --- coherent configurations. We also give a third characterization of uniform schemes in terms of the Krein parameters, and derive information on the primitive idempotents of such a scheme. In the second half of the paper, we apply these results to cometric association schemes. We show that each such scheme is uniform if and only if it is Q-antipodal, and derive results on the parameters of the subschemes and dismantled schemes of cometric Q-antipodal schemes. We revisit the correspondence between uniform indecomposable three-class schemes and linked systems of symmetric designs, and show that these are cometric Q-antipodal. We obtain a characterization of cometric Q-antipodal four-class schemes in terms of only a few parameters, and show that any strongly regular graph with a ("non-exceptional") strongly regular decomposition gives rise to such a scheme. Hemisystems in generalized quadrangles provide interesting examples of such decompositions. We finish with a short discussion of five-class schemes as well as a list of all feasible parameter sets for cometric Q-antipodal four-class schemes with at most six fibres and fibre size at most 2000, and describe the known examples. Most of these examples are related to groups, codes, and geometries.Comment: 42 pages, 1 figure, 1 table. Published version, minor revisions, April 201

Mock galaxy catalogs using the quick particle mesh method

Sophisticated analysis of modern large-scale structure surveys requires mock catalogs. Mock catalogs are used to optimize survey design, test reduction and analysis pipelines, make theoretical predictions for basic observables and propagate errors through complex analysis chains. We present a new method, which we call "quick particle mesh", for generating many large-volume, approximate mock catalogs at low computational cost. The method is based on using rapid, low-resolution particle mesh simulations that accurately reproduce the large-scale dark matter density field. Particles are sampled from the density field based on their local density such that they have N-point statistics nearly equivalent to the halos resolved in high-resolution simulations, creating a set of mock halos that can be populated using halo occupation methods to create galaxy mocks for a variety of possible target classes.Comment: 13 pages, 16 figures. Matches version accepted by MNRAS. Code available at http://github.com/mockFactor

Reaching for the Stars: A Constructivist Investigation of Astrology as a Tool for Self-Discovery in a New Age of Leadership

To fully understand leadership in today’s world, we need a radical reconceptualization of the developmental process required to lead. Changing paradigms demands new perspectives on leadership; these new paradigms suggest leaders must turn inward and develop knowledge of their inner selves to realize their full potential as leaders. Astrology is an ancient way of knowing and making sense of the world and one’s place in it that provides benefits to many people in our modern world, despite fervent academic, religious, and scientific criticism. Astrology is more than a divination tool. It is an entire epistemology of self in relation to the cosmos that addresses the transcendent nature of human beings. In our increasingly uncertain world, millions of people are turning to astrology in search of greater self-knowledge and meaning for their lives. This exploratory study investigated (a) the use of astrological knowledge as a tool for promoting self-discovery, self-awareness, and self-development and (b) the extent to which this tool influences changes in an individual’s self. To date, no empirical studies have been conducted to explore astrology as a developmental tool, despite its prevalence in popular culture. The data in this study documents that astrology is a useful tool for self-discovery, understanding interpersonal relationships, understanding the subconscious, healing, meaning making, making sense of change, personal guidance, and personal development. The study leaves open questions about astrology’s predictive powers and concentrates, instead, on its developmental impact on practitioners. In short, it does not directly address the academic community’s criticism of astrology and the ultimately unanswerable question of whether astrological readings are factual or merely highly functional fictions for the research participants. While the demands of knowing one’s self are significant for exercising leadership effectively in contemporary contexts, the study of self and the ways in which individuals promote self-awareness have been minimally addressed in the leadership literature to date. This situation was the impetus for this study. The study utilized a constructivist grounded theory perspective and an interview-based methodology with both astrologers and their clients to explore the phenomenon of astrological practice as a tool for leader development

Compressed intramolecular dispersion interactions.

The feasibility of the compression of localized virtual orbitals is explored in the context of intramolecular long-range dispersion interactions. Singular value decomposition (SVD) of coupled cluster doubles amplitudes associated with the dispersion interactions is analyzed for a number of long-chain systems, including saturated and unsaturated hydrocarbons and a silane chain. Further decomposition of the most important amplitudes obtained from these SVDs allows for the analysis of the dispersion-specific virtual orbitals that are naturally localized. Consistent with previous work on intermolecular dispersion interactions in dimers, it is found that three important geminals arise and account for the majority of dispersion interactions at the long range, even in the many body intramolecular case. Furthermore, it is shown that as few as three localized virtual orbitals per occupied orbital can be enough to capture all pairwise long-range dispersion interactions within a molecule

Tile Pattern KL-Divergence for Analysing and Evolving Game Levels

This paper provides a detailed investigation of using the Kullback-Leibler (KL) Divergence as a way to compare and analyse game-levels, and hence to use the measure as the objective function of an evolutionary algorithm to evolve new levels. We describe the benefits of its asymmetry for level analysis and demonstrate how (not surprisingly) the quality of the results depends on the features used. Here we use tile-patterns of various sizes as features. When using the measure for evolution-based level generation, we demonstrate that the choice of variation operator is critical in order to provide an efficient search process, and introduce a novel convolutional mutation operator to facilitate this. We compare the results with alternative generators, including evolving in the latent space of generative adversarial networks, and Wave Function Collapse. The results clearly show the proposed method to provide competitive performance, providing reasonable quality results with very fast training and reasonably fast generation.Comment: 8 pages plus references. Proceedings of GECCO 201

Impact on maternity professionals of novel approaches to clinical audit feedback

We compared three approaches to feedback of clinical audit findings relating to miscarriage in 15 Scottish maternity services (printed report alone; report plus Action Planning Letter; report plus face-to-face Facilitated Action Planning). We surveyed clinicians to measure Theory of Planned Behaviour constructs (in the context of two audit criteria) before and after feedback (n=253) and assessed perceptions of the audit through in-depth interviews (n=17). Pre-feedback, clinicians had positive attitudes and strong subjective norms and intentions to comply, although perceived behavioural control was lower. Generally, positive attitudes, subjective norms and intentions increased after feedback but for one of the two criteria (providing a 7-day miscarriage service), perceived behavioural control decreased. No changes over time reached statistical significance and analysis of covariance (adjusting for pre-feedback scores) showed no consistent relationships between method of feedback and post-feedback construct scores. Interviews revealed positive perceptions of audit but frustration at lack of capacity to implement changes. While interventions which increased intensity of feedback proved feasible and acceptable to clinicians, we were unable to demonstrate that they increased intention to comply with audit criteria.This study was funded by NHS Quality Improvement Scotland

Pedagogical practices of mathematical literacy educators

Research Project in Education for: Masters in EducationThis study analyzed the pedagogical practices of three Grade 10 Mathematical Literacy (ML) educators. The rationale behind the study was to add information and insight into the very new and under researched Further Education and Training secondary school subject of ML. Botha (2011) discussed how one of the main concerns with ML integration into the South African national curriculum was that the educators being asked to teach ML were moved into it from other subjects without any real education or training, and so when teaching, relied on previously learned pedagogical practices from other subjects. It is the contention of this study that this is a real issue in terms of the teaching of ML in classrooms and in terms of damaging its perceived academic status. In order to offer insight into how ML is its own distinct subject and not simply a lesser version of Mathematics, this study analyzed three lessons of each of the three educators through the lens of Pedagogical Link Making (PLM) (Scott, Mortimer, & Ametller, 2011). PLM was the conceptual framework that guided the observations and post observation interviews, and through analysis of the educators’ pedagogical practices as well as a thematic analysis of discussion points during the interviews, this study came to five major findings. The findings suggested that the ML educators were not properly educated in ML pedagogy and that the educators made the majority of pedagogical decisions in the classroom based on generating learner interest and motivation for work. It also found that the educators used many of the links outlined by PLM, but also admitted to holding a lower academic expectation of ML and ML learners. A call is made to increase research into the relatively new subject of ML along the lines of pedagogical practices in order to assist new ML educators to translate and transmit the goals and content of ML provided for by the Curriculum and Assessment Policy Statement (CAP