441 research outputs found

    Finite-width feed and load models

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    We demonstrate a new method of applying the feed model for the method of moments (MoM) formulation for the electric field integral equation (EFIE). The model is based around a previously reported magnetic ribbon current model which is accurate and allows for a finite width of the feed port. However, with proper approximations, one can reduce the formulation such that the magnetic field operator can be removed in order to simplify computations arising from the curl of the dyadic Green's function and its singularities. We show here that the new feed model can also be used to model a lumped element. © 1963-2012 IEEE.published_or_final_versio

    A memory saving vector fast multipole algorithm for solving the augmented EFIE

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    An augmented EFIE (A-EFIE)[9], [10] has been proposed to separate the contributions of the vector potential and the scalar potential for avoiding the imbalance at low frequencies. The corresponding low frequency fast multipole algorithm (LFFMA) [11] was also developed for solving the A-EFIE. Instead of the factorization of the scalar Green's function by using scalar addition theorem in the LF-FMA, we adopt the vector addition theorem for the factorization of the dyadic Green's function to realize memory savings. We are to develop a vector fast multipole algorithm for solving the A-EFIE. © 2010 IEEE.published_or_final_versionThe URSI International Symposium on Electromagnetic Theory (EMTS 2010), Berlin, Germany, 16-19 August 2010. In Proceedings of the URSI International Symposium on Electromagnetic Theory, 2010, p. 134-13

    Solving multi-scale low frequency electromagnetic problems

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    In this paper, we will discuss two methods to tackle the low-frequency, multi-scale electromagnetics problem. First we will discuss the augmented electric field integral equation (AEFIE), and then, we will discuss the equivalence principle algorithm (EPA). The AEFIE allows the solution of such problems without the need to perform a loop search of a complex structure. The EPA allows the separation of circuit physics from wave physics in a multiscale problem. Hybridization of these two methods will be discussed.published_or_final_versionThe 4th European Conference on Antennas and Propagation (EuCAP) 2010, Barcelona, Spain, 12-16 April 2010. In Proceedings of the 4th EuCAP, 2010, p. 1-

    Generalized modal expansion of electromagnetic field in 2-D bounded and unbounded media

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    A generalized modal expansion theory is presented to investigate and illustrate the physics of wave-matter interaction within arbitrary two-dimensional (2-D) bounded and unbounded electromagnetic problems. We start with the bounded case where the field excited by any sources is expanded with a complete set of biorthogonal eigenmodes. In regard to non-Hermitian or nonreciprocal problems, an auxiliary system is constructed to seek for the modal-expansion solution. We arrive at the unbounded case when the boundary tends to infinity or is replaced by the perfectly matched layer (PML). Modes are approximately categorized into two types: trapped modes and radiation modes, which respond differently to environment variations. When coupled with the source, these modes contribute to the modal-expansion solution with different weights, which leads to a reduced modal representation of the excited field in some geometries. © 2002-2011 IEEE.published_or_final_versio

    Neuropeptides encoded by nlp-49 modulate locomotion, arousal and egg-laying behaviours in Caenorhabditis elegans via the receptor SEB-3

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    Neuropeptide signalling has been implicated in a wide variety of biological processes in diverse organisms, from invertebrates to humans. The Caenorhabditis elegans genome has at least 154 neuropeptide precursor genes, encoding over 300 bioactive peptides. These neuromodulators are thought to largely signal beyond ‘wired’ chemical/electrical synapse connections, therefore creating a ‘wireless’ network for neuronal communication. Here, we investigated how behavioural states are affected by neuropeptide signalling through the G protein-coupled receptor SEB-3, which belongs to a bilaterian family of orphan secretin receptors. Using reverse pharmacology, we identified the neuropeptide NLP-49 as a ligand of this evolutionarily conserved neuropeptide receptor. Our findings demonstrate novel roles for NLP-49 and SEB-3 in locomotion, arousal and egg-laying. Specifically, high-content analysis of locomotor behaviour indicates that seb-3 and nlp-49 deletion mutants cause remarkably similar abnormalities in movement dynamics, which are reversed by overexpression of wild-type transgenes. Overexpression of NLP-49 in AVK interneurons leads to heightened locomotor arousal, an effect that is dependent on seb-3. Finally, seb-3 and nlp-49 mutants also show constitutive egg-laying in liquid medium and alter the temporal pattern of egg-laying in similar ways. Together, these results provide in vivo evidence that NLP-49 peptides act through SEB-3 to modulate behaviour, and highlight the importance of neuropeptide signalling in the control of behavioural states. This article is part of a discussion meeting issue ‘Connectome to behaviour: modelling C. elegans at cellular resolution’

    Meadowdale High School Student with Disabilities Finds Job in UD Cafeteria; UD Assistant Geology Professor Plots City\u27s Glacial Deposits on High-Tech Map

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    Feature leads for the media: The University of Dayton and Dayton Public Schools have teamed up to place a Meadowdale High School student with multiple disabilities in a job with Kennedy Union Food Service; UD geology faculty member J. Michael Clinch is using a computer to create Dayton and Montgomery County\u27s first extensive and only automated inventory of glacial and post-glacial deposits on a U.S. Geological Survey base map

    "When nothing happens, nobody is afraid!" beliefs and perceptions around self-care and health-seeking behaviours: Voices of patients living with diabetic lower extremity amputation in primary care.

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    Self-management and self-care are the cornerstone of diabetes care and an essential part of successfully preventing or delaying diabetes complications. Yet, despite being armed with the required information and guidance for self-management, self-care and adherence to foot self-care recommendations and compliance to medication among patients with diabetic foot ulcer and diabetic lower extremity amputations remain low and suboptimal. This study reveals in-depth account of nine such patients' beliefs and perceptions around their illness, their self-care, and their health-seeking behaviours. Patients living with diabetic lower extremity amputation displayed profound lack of knowledge of self-care of diabetes and foot and passive health-related behaviours. The overarching sense that "when nothing happens, nobody is afraid," points to a lack of motivation in taking charge of one's own health, whether this is with reference to treatment or care adherence, following recommended self-care advice, or seeking timely treatment. The Health Beliefs Model provides the theoretical framework for probing into the factors for the participants' suboptimal self-care and passive health-seeking behaviours. Two themes emerged from data analysis: profound knowledge deficit and passive health-related behaviours. The beliefs and perceptions around self-care and health-seeking behaviours for patients with lower extremity amputation are interpreted as the "ignorant self" with passive health-seeking behaviours. Patients with diabetes and diabetic foot diseases may benefit from personalized education, motivational interviewing, and family support

    Struggling for normality: experiences of patients with diabetic lower extremity amputations and post-amputation wounds in primary care.

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    AIM: To explore the experiences of patients living with diabetic lower extremity amputation (DLEA) and its post-amputation wound in primary care. BACKGROUND: DLEA, including both minor and major amputation, is a life-altering condition that brings numerous challenges to an individual's life. Post-amputation physical wound healing is complicated and challenging because of wound dehiscence and prolonged healing times. Understanding patients' experiences after DLEA with a post-amputation wound will enable healthcare professionals to develop interventions to assist patients in physical healing and psychosocial recovery. METHODS: This study employs a qualitative design using interpretative phenomenological analysis (IPA). A purposive maximum variation sample of nine patients who had had lower extremity amputations and post-amputation wound attributed to diabetes in the previous 12 months was recruited from a primary care setting in Singapore. Semi-structured audio recorded one-to-one interviews with a duration of 45-60 min each were conducted between September 2018 and January 2019. The interviews were transcribed verbatim and analysed using IPA. FINDINGS: The essential meaning of the phenomenon 'the lived experiences for patients with DLEA and post-amputated wound' can be interpreted as 'struggling for "normality"' which encompasses four domains of sense making: physical loss disrupted normality, emotional impact aggravated the disrupted normality, social challenges further provoked the disrupted normality, and attempt to regain normality. The study highlights the complex physical and psychosocial transition facing patients after DLEA before post-amputation wound closure. In primary care, an amputation, whether minor or major, is a life-altering experience that requires physical healing, emotional recovery, and social adaptation to regain normality. Patients living with DLEA and a post-amputation wound may benefit from an interdisciplinary team care model to assist them with physical and psychosocial adjustment and resume normality

    Review of multi-scale electromagnetic modeling

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    This paper reviews various methods to solve multiscale problems ranging from low-frequency methods to very high-frequency methods. ©2010 IEEE.published_or_final_versionThe 2010 International Conference on Electromagnetics in Advanced Applications (ICEAA), Sydney, N.S.W., 20-24 September 2010. In Proceedings of ICEAA'10, 2010, p. 641-64

    Development of the SPECULOOS exoplanet search project

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    SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) aims to perform a transit search on the nearest (<40<40pc) ultracool (<3000<3000K) dwarf stars. The project's main motivation is to discover potentially habitable planets well-suited for detailed atmospheric characterisation with upcoming giant telescopes, like the James Webb Space Telescope (JWST) and European Large Telescope (ELT). The project is based on a network of 1m robotic telescopes, namely the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in Tenerife, and the SAINT-Ex telescope in San Pedro M\'artir, Mexico. The prototype survey of the SPECULOOS project on the 60~cm TRAPPIST telescope (Chile) discovered the TRAPPIST-1 system, composed of seven temperate Earth-sized planets orbiting a nearby (12~pc) Jupiter-sized star. In this paper, we review the current status of SPECULOOS, its first results, the plans for its development, and its connection to the Transiting Exoplanet Survey Satellite (TESS) and JWST
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