2,684 research outputs found

    Learning Unitary Operators with Help From u(n)

    Full text link
    A major challenge in the training of recurrent neural networks is the so-called vanishing or exploding gradient problem. The use of a norm-preserving transition operator can address this issue, but parametrization is challenging. In this work we focus on unitary operators and describe a parametrization using the Lie algebra u(n)\mathfrak{u}(n) associated with the Lie group U(n)U(n) of nĂ—nn \times n unitary matrices. The exponential map provides a correspondence between these spaces, and allows us to define a unitary matrix using n2n^2 real coefficients relative to a basis of the Lie algebra. The parametrization is closed under additive updates of these coefficients, and thus provides a simple space in which to do gradient descent. We demonstrate the effectiveness of this parametrization on the problem of learning arbitrary unitary operators, comparing to several baselines and outperforming a recently-proposed lower-dimensional parametrization. We additionally use our parametrization to generalize a recently-proposed unitary recurrent neural network to arbitrary unitary matrices, using it to solve standard long-memory tasks.Comment: 9 pages, 3 figures, 5 figures inc. subfigures, to appear at AAAI-1

    A Generative Model of Words and Relationships from Multiple Sources

    Full text link
    Neural language models are a powerful tool to embed words into semantic vector spaces. However, learning such models generally relies on the availability of abundant and diverse training examples. In highly specialised domains this requirement may not be met due to difficulties in obtaining a large corpus, or the limited range of expression in average use. Such domains may encode prior knowledge about entities in a knowledge base or ontology. We propose a generative model which integrates evidence from diverse data sources, enabling the sharing of semantic information. We achieve this by generalising the concept of co-occurrence from distributional semantics to include other relationships between entities or words, which we model as affine transformations on the embedding space. We demonstrate the effectiveness of this approach by outperforming recent models on a link prediction task and demonstrating its ability to profit from partially or fully unobserved data training labels. We further demonstrate the usefulness of learning from different data sources with overlapping vocabularies.Comment: 8 pages, 5 figures; incorporated feedback from reviewers; to appear in Proceedings of the Thirtieth AAAI Conference on Artificial Intelligence 201

    The effects of immigration and media influence on body image among Pakistani men

    Get PDF
    This study examined the role of media influence and immigration on body image among Pakistani men. Attitudes toward the body were compared between those living in Pakistan (n = 56) and those who had immigrated to the United Arab Emirates (n = 58). Results of a factorial analysis of variance demonstrated a significant main effect of immigrant status. Pakistani men living in the United Arab Emirates displayed poorer body image than those in the Pakistan sample. Results also indicated a second main effect of media influence.Those highly influenced by the media displayed poorer body image. No interaction effect was observed between immigrant status and media influence on body image. These findings suggest that media influence and immigration are among important risk factors for the development of negative body image among non-Western men. Interventions designed to address the negative effects of the media and immigration may be effective at reducing body image disorders and other related health problems in this population

    MAST flight system dynamic performance

    Get PDF
    The MAST Flight System as a test bed for large space structure control algorithms is discussed. An overview is given of the control system architecture. The actuators, the sensors, the control computer, and the baseline damping algorithm are discussed

    Biopsychosocial implications of living with multiple sclerosis: a qualitative study using interpretative phenomenological analysis

    Get PDF
    Background: Multiple sclerosis (MS) is estimated to affect 2.8 million people worldwide, with increasing prevalence in all world regions (Walton et al). While there is no cure for MS, medication and lifestyle modifications can slow disease progression and enhance patients’ quality of life. The biopsychosocial model of health recognises important interactions among biological, psychological and social factors in illness, including those relating to illness management, which contribute to the experience of those diagnosed with MS. Objective: This qualitative, idiographic study aimed to explore the lived experiences of patients in the United Arab Emirates (UAE) diagnosed with S. Methods: Semistructured interviews were conducted with a purposive sample of eight patients with MS ranging in age from 25 to 56 years. All participants were residing in the UAE at the time of data collection. Interpretative phenomenological analysis was used to analyse the data. Results: Three superordinate themes were identified from patients’ candid accounts of their lives with MS, highlighting issues of illness management, acceptance and gratitude, and adaptive coping. These themes broadly illustrate biological, psychological and social aspects of patients’ MS experiences. Conclusion: The study emphasised the importance of adopting the biopsychosocial model to treat and manage MS. Additionally, it highlights the need for routine assessment and early, multidimensional approach with multidisciplinary team efforts to improve patients’ quality of life

    Tourist perceptions of Dubai and Expo2020

    Get PDF
    In 2020, Dubai will host the World Expo. Not only will the Expo 2020 draw an expected 25 million tourists, but since the announcement, it has been a focal point for progressing towards the lofty goals of the Dubai tourism vision, mobilizing people, companies, projects, and the entire country towards 2020. This particular mega-event is a crucial component of the wider branding strategy. Expo2020 has also played a significant role in the marketing communications and branding of Dubai since its announcement through multiple communication channels. The purpose of this paper is to explore tourists’ perceptions of Dubai and Expo 2020 and to understand tourists’ attitudes and perceived value of different information sources and marketing channels. In doing so, this paper will provide some initial insights into understanding tourists' perceptions and attitudes towards Dubai in relation to Expo2020
    • …
    corecore