29,092 research outputs found
Application of Multichannel Active Vibration Control in a Multistage Gear Transmission System
Gears are the most important parts of rotating machinery and power transmission devices. When gears are engaged in meshing transmission, vibration will occur due to factors such as gear machining errors, meshing rigidity, and meshing impact. The traditional FxLMS algorithm, as a common active vibration algorithm, has been widely studied and applied in gear transmission system active vibration control in recent years. However, it is difficult to achieve good performance in convergence speed and convergence precision at the same time. This paper proposes a variable-step-size multichannel FxLMS algorithm based on the sampling function, which accelerates the convergence speed in the initial stage of iteration, improves the convergence accuracy in the steady-state adaptive stage, and makes the modified algorithm more robust. Simulations verify the effectiveness of the algorithm. An experimental platform for active vibration control of the secondary gear transmission system is built. A piezoelectric actuator is installed on an additional gear shaft to form an active structure and equipped with a signal acquisition system and a control system; the proposed variable-step-size multichannel FxLMS algorithm is experimentally verified. The experimental results show that the proposed multichannel variable-step-size FxLMS algorithm has more accurate convergence accuracy than the traditional FxLMS algorithm, and the convergence accuracy can be increased up to 123%
ENHANCING STUDENT ENGAGEMENT, TEACHER SELF-EFFICACY, AND PRINCIPAL LEADERSHIP SKILLS THROUGH MORNING MEETING IN AN ONLINE LEARNING ENVIRONMENT
This study examined the experiences of educators in a small, rural elementary school who provided live instruction in an online setting during the COVID-19 pandemic. The scholarly practitioner collaborated with inquiry partners to enhance student engagement, teacher self-efficacy, and principal leadership skills by implementing Morning Meeting, a social and emotional learning program from Responsive Classroom®, when students participated in remote online learning. The scholarly practitioner used over four decades of research about efficacy and identified leadership strategies and approaches that assisted in building individual and collective teacher efficacy so that teachers could effectively engage students.
Behavioral, emotional, and cognitive engagement were identified in research and used by teachers to determine the quality of participation in Morning Meeting. Teachers took daily and weekly attendance to measure engagement, and the scholarly practitioner facilitated team meetings with groups of teachers to compile comments and statements regarding student engagement. These statements were coded using pre-selected codes based on research about types of student engagement.
The scholarly practitioner facilitated the administration of a pre-study and post-study Teacher Self-Efficacy Scale so that individual, grade-span, and full-school efficacy data could be compiled. In addition, the scholarly practitioner held team meetings with the teachers to compile comments and categorize those statements into four areas: job accomplishment, skill development, social interaction, and coping with job stress. These four areas were also coded using the four categories described on the Teacher Self-Efficacy Scale.
The scholarly practitioner also maintained a journal using a self-reflection tool about the lived experiences before, during, and after the study. The emphasis on this journal was about the development and growth of leadership skills, and the categories were pre-coded using Bernard Bass’s categories of transformational leadership: individualized consideration, inspirational motivation, idealized influence, and intellectual stimulation.
Student engagement increased throughout the study, and 77 percent of students were fully engaged during the study. Teachers expressed an increase in collective efficacy at the conclusion of the study, and six of the eight teachers reported individual increases in efficacy. The scholarly practitioner’s use of differentiation within the context of transformational leadership was observed most frequently in the study
Sponsorship image and value creation in E-sports
.E-sports games can drive the sports industry forward and sponsorship is the best way to engage consumers of this new sport. The purpose of this study is to examine the effect of sponsorship image and consumer participation in co-creation consumption activities on fans’ sponsorship response (represented by the variables interest, purchase intention and word of mouth) in e-sports. Four antecedent variables build sponsorship image (i.e., ubiquity of sport, sincerity of sponsor, attitude to sponsor and team identification). A quantitative approach is used for the purposes of this study. Some 445 questionnaires were filled in by fans who watch e-sports in Spain; these are analyzed using partial least squares structural equation modeling (PLS-SEM). The outcomes show that sponsor antecedents are crucial factors if a sponsor wants to change their sponsorship image and influence sponsorship response, and that it is also possible to use participation to improve responsesS
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Meaning-Making Practices of Emergent Arabic–English Bilingual Kindergarten Children in Cairo
The number of British Schools in the Middle East and North Africa (MENA) region is growing. The National Curriculum of England is used by an increasing number of such schools. As well as exporting a culturally-specific curriculum, these schools usually adopt an ideology of monolingualism, thus potentially limiting communication for emergent bilinguals and failing to acknowledge the multiple ways of meaning-making.
Current studies of translanguaging are moving the focus to multimodal forms of communication as a resource for thinking and communicating (GarcÃa and Wei 2014, Wei 2018). Building on the work of Kress (1997, 2010) I explore pre-school emergent bilinguals’ wider signifying practices and create an analytical framework, which I call MMTL (multimodal translanguaging), used as a lens to illustrate meaning-making.
Valley Hill in Cairo, Egypt is a British school which encourages ‘English-only’ as the medium of instruction in the kindergarten. Using a case study methodology, this research explores the meaning-making practices of eight emergent bilingual children aged 3–4 during child-initiated play, later reduced to four in the thesis to provide a detailed multimodal analysis. The principal aim is to explore their speech, gaze, gesture, and their engagement (layout/position) with artefacts during play.
The findings of this study suggest that although there is an ‘English-only’ approach, these young emergent bilingual children are meaning-making in a variety of ways. Children are translanguaging but it is never in isolation from other modes of communication. Emergent bilinguals use a range of modes to mediate their understanding and communication with others. They use gesture, gaze, and artefacts alongside translingual practices to move meaning across to more accessible modes, enabling communication and understanding. The implications for schools should be to embrace such hybrid practices and for teachers to be more responsive to young children’s meaning-making to enable learning
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European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) Expert Consensus Statement on the state of genetic testing for cardiac diseases.
Image classification over unknown and anomalous domains
A longstanding goal in computer vision research is to develop methods that are simultaneously applicable to a broad range of prediction problems. In contrast to this, models often perform best when they are specialized to some task or data type. This thesis investigates the challenges of learning models that generalize well over multiple unknown or anomalous modes and domains in data, and presents new solutions for learning robustly in this setting.
Initial investigations focus on normalization for distributions that contain multiple sources (e.g. images in different styles like cartoons or photos). Experiments demonstrate the extent to which existing modules, batch normalization in particular, struggle with such heterogeneous data, and a new solution is proposed that can better handle data from multiple visual modes, using differing sample statistics for each.
While ideas to counter the overspecialization of models have been formulated in sub-disciplines of transfer learning, e.g. multi-domain and multi-task learning, these usually rely on the existence of meta information, such as task or domain labels. Relaxing this assumption gives rise to a new transfer learning setting, called latent domain learning in this thesis, in which training and inference are carried out over data from multiple visual domains, without domain-level annotations. Customized solutions are required for this, as the performance of standard models degrades: a new data augmentation technique that interpolates between latent domains in an unsupervised way is presented, alongside a dedicated module that sparsely accounts for hidden domains in data, without requiring domain labels to do so.
In addition, the thesis studies the problem of classifying previously unseen or anomalous modes in data, a fundamental problem in one-class learning, and anomaly detection in particular. While recent ideas have been focused on developing self-supervised solutions for the one-class setting, in this thesis new methods based on transfer learning are formulated. Extensive experimental evidence demonstrates that a transfer-based perspective benefits new problems that have recently been proposed in anomaly detection literature, in particular challenging semantic detection tasks
Data-to-text generation with neural planning
In this thesis, we consider the task of data-to-text generation, which takes non-linguistic
structures as input and produces textual output. The inputs can take the form of
database tables, spreadsheets, charts, and so on. The main application of data-to-text
generation is to present information in a textual format which makes it accessible to
a layperson who may otherwise find it problematic to understand numerical figures.
The task can also automate routine document generation jobs, thus improving human
efficiency. We focus on generating long-form text, i.e., documents with multiple paragraphs. Recent approaches to data-to-text generation have adopted the very successful
encoder-decoder architecture or its variants. These models generate fluent (but often
imprecise) text and perform quite poorly at selecting appropriate content and ordering
it coherently. This thesis focuses on overcoming these issues by integrating content
planning with neural models. We hypothesize data-to-text generation will benefit from
explicit planning, which manifests itself in (a) micro planning, (b) latent entity planning, and (c) macro planning. Throughout this thesis, we assume the input to our
generator are tables (with records) in the sports domain. And the output are summaries
describing what happened in the game (e.g., who won/lost, ..., scored, etc.).
We first describe our work on integrating fine-grained or micro plans with data-to-text generation. As part of this, we generate a micro plan highlighting which records
should be mentioned and in which order, and then generate the document while taking
the micro plan into account.
We then show how data-to-text generation can benefit from higher level latent entity planning. Here, we make use of entity-specific representations which are dynam ically updated. The text is generated conditioned on entity representations and the
records corresponding to the entities by using hierarchical attention at each time step.
We then combine planning with the high level organization of entities, events, and
their interactions. Such coarse-grained macro plans are learnt from data and given
as input to the generator. Finally, we present work on making macro plans latent
while incrementally generating a document paragraph by paragraph. We infer latent
plans sequentially with a structured variational model while interleaving the steps of
planning and generation. Text is generated by conditioning on previous variational
decisions and previously generated text.
Overall our results show that planning makes data-to-text generation more interpretable, improves the factuality and coherence of the generated documents and re duces redundancy in the output document
Unraveling the effect of sex on human genetic architecture
Sex is arguably the most important differentiating characteristic in most mammalian
species, separating populations into different groups, with varying behaviors, morphologies,
and physiologies based on their complement of sex chromosomes, amongst other factors. In
humans, despite males and females sharing nearly identical genomes, there are differences
between the sexes in complex traits and in the risk of a wide array of diseases. Sex provides
the genome with a distinct hormonal milieu, differential gene expression, and environmental
pressures arising from gender societal roles. This thus poses the possibility of observing
gene by sex (GxS) interactions between the sexes that may contribute to some of the
phenotypic differences observed. In recent years, there has been growing evidence of GxS,
with common genetic variation presenting different effects on males and females. These
studies have however been limited in regards to the number of traits studied and/or
statistical power. Understanding sex differences in genetic architecture is of great
importance as this could lead to improved understanding of potential differences in
underlying biological pathways and disease etiology between the sexes and in turn help
inform personalised treatments and precision medicine.
In this thesis we provide insights into both the scope and mechanism of GxS across the
genome of circa 450,000 individuals of European ancestry and 530 complex traits in the UK
Biobank. We found small yet widespread differences in genetic architecture across traits
through the calculation of sex-specific heritability, genetic correlations, and sex-stratified
genome-wide association studies (GWAS). We further investigated whether sex-agnostic
(non-stratified) efforts could potentially be missing information of interest, including sex-specific trait-relevant loci and increased phenotype prediction accuracies. Finally, we
studied the potential functional role of sex differences in genetic architecture through sex
biased expression quantitative trait loci (eQTL) and gene-level analyses.
Overall, this study marks a broad examination of the genetics of sex differences. Our findings
parallel previous reports, suggesting the presence of sexual genetic heterogeneity across
complex traits of generally modest magnitude. Furthermore, our results suggest the need to
consider sex-stratified analyses in future studies in order to shed light into possible sex-specific molecular mechanisms
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