5,430 research outputs found

    Speech Dereverberation Based on Integrated Deep and Ensemble Learning Algorithm

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    Reverberation, which is generally caused by sound reflections from walls, ceilings, and floors, can result in severe performance degradation of acoustic applications. Due to a complicated combination of attenuation and time-delay effects, the reverberation property is difficult to characterize, and it remains a challenging task to effectively retrieve the anechoic speech signals from reverberation ones. In the present study, we proposed a novel integrated deep and ensemble learning algorithm (IDEA) for speech dereverberation. The IDEA consists of offline and online phases. In the offline phase, we train multiple dereverberation models, each aiming to precisely dereverb speech signals in a particular acoustic environment; then a unified fusion function is estimated that aims to integrate the information of multiple dereverberation models. In the online phase, an input utterance is first processed by each of the dereverberation models. The outputs of all models are integrated accordingly to generate the final anechoic signal. We evaluated the IDEA on designed acoustic environments, including both matched and mismatched conditions of the training and testing data. Experimental results confirm that the proposed IDEA outperforms single deep-neural-network-based dereverberation model with the same model architecture and training data

    Elderly Patients with Laryngeal and Hypopharyngeal Cancer Undergoing Total Pharyngolaryngectomy with a Radial Forearm, Free Flap-reconstructed Phonation Tube

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    SummaryBackgroundThe radial forearm, free-flap (RFFF)-reconstructed phonation tube was developed for functional restoration of voice after total pharyngolaryngectomy. We aimed to report the efficacy of RFFF phonation tube after pharyngolaryngectomy with radiotherapy (RT) or concurrent chemoradiation therapy (CCRT) with intensity-modulated radiotherapy (IMRT) for elderly.Materials and methodsTen patients with laryngeal and hypopharyngeal cancer underwent total pharyngolaryngectomy and one-stage reconstruction with an RFFF-accompanied phonation tube, followed by RT or CCRT. Voice restoration was achieved with the RFFF-reconstructed phonation tube. Functional outcomes of phonation and speech were evaluated and scored.ResultsPercentages of stage III and stage IV patients among all participants were 10% and 90%, respectively. The median follow-up time was 31 months (range, 4–67 months). Almost 9 out of 10 (90%) patients experienced phonation efficacy greater than 80%. The maximal phonation time per breath was 70% longer than 3 sec. The graded as mild of wet voice was 90%. Percentage of mild decreased loudness was 60% and that of low and high pitch was 80%. Of the 10 patients, 40% could count more than 10 and 70% could pronounce more than 1 to 5 words per breath. After RT or CCRT, of patients had moderately good to excellent speech intelligibility.ConclusionThe RFFF phonation tube that was used after pharyngolaryngectomy with RT or CCRT with IMRT provided acceptable complications and functional restoration of voice for elderly patients

    Library Assessment and Data Analytics in the Big Data Era: Practice and Policies

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    Emerging technologies have offered libraries and librarians new ways and methods to collect and analyze data in the era of accountability to justify their value and contributions. For example, Gallagher, Bauer and Dollar (2005) analyzed the paper and online journal usage from all possible data sources and discovered that users at the Yale Medical Library preferred the electronic format of articles to the print version. After this discovery, they were able to take necessary steps to adjust their journal subscriptions. Many library professionals advocate such data-driven library management to strengthen and specify library budget proposals

    Dexamethasone Down-regulates Osteocalcin in Bone Cells through Leptin Pathway

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    Glucocorticoid therapy, especially at higher doses, is associated with significantadverse side effects including osteoporosis. Leptin, secreted from adipose tissue, has diverse effects on bone tissue regulation. As glucocorticoids stimulate leptin synthesis and secretion directly in adipose tissue we hypothesised that dexamethasone (DEX) induced osteoporosis may, in part, be mediated by an osteoblast dependent leptin-leptin receptor pathway. Human bone cells expressed leptin and leptin receptors (Ob-Ra and Ob-Rb). DEX increased leptin, Ob-Ra and Ob-Rb expression in a dose-dependent manner while decreasing expression of osteocalcin. In the presence of leptin, Cbfa1 and osteonectin expression showed no significant change, whereas osteocalcin expression was decreased. Recombinant human quadruple antagonist leptin suppressed DEX-induced osteocalcin downregulation. The signaling pathway involved up-regulation of JAK2. In conclusion, upregulation of leptin and Ob-Rb in human bone cells by DEX is associated with own-regulation of osteocalcin expression. The down regulation of osteocalcin by DEX was partially through a leptin autocrine/paracrine loop. Adverse effects of DEX on the skeleton may be modified by targeting leptin signaling pathways

    Impact of Aerosols on Convective Clouds and Precipitation

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    Aerosols are a critical factor in the atmospheric hydrological cycle and radiation budget. As a major reason for clouds to form and a significant attenuator of solar radiation, aerosols affect climate in several ways. Current research suggests that aerosol effects on clouds could further extend to precipitation, both through the formation of cloud particles and by exerting persistent radiative forcing on the climate system that disturbs dynamics. However, the various mechanisms behind these effects, in particular the ones connected to precipitation, are not yet well understood. The atmospheric and climate communities have long been working to gain a better grasp of these critical effects and hence to reduce the significant uncertainties in climate prediction resulting from such a lack of adequate knowledge. The central theme of this paper is to review past efforts and summarize our current understanding of the effect of aerosols on precipitation processes from theoretical analysis of microphysics, observational evidence, and a range of numerical model simulations. In addition, the discrepancy between results simulated by models, as well as that between simulations and observations will be presented. Specifically, this paper will address the following topics: (1) fundamental theories of aerosol effects on microphysics and precipitation processes, (2) observational evidence of the effect of aerosols on precipitation processes, (3) signatures of the aerosol impact on precipitation from large-scale analyses, (4) results from cloud-resolving model simulations, and (5) results from large-scale numerical model simulations. Finally, several future research directions on aerosol - precipitation interactions are suggested

    A passive control method of HAWT blade cyclical aerodynamic load induced by wind shear

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    Abstract: Modern wind turbines are mainly horizontal axis and operate in bottom atmospheric boundary layer driven by wind shear flow, therefore as the blades rotating the aerodynamic load vary cyclically, with horizontal axis wind turbine (HAWT) large-scaling the cyclical characteristic becomes more obvious, shortening blade life and increasing cost of wind turbine. As the development of wind turbine largescaling is the essential trend, load fluctuation control is more and more critical in HAWT design and manufacture. In common, individual pitch control is introduced to solve the problem, but cost much energy from electric net. In this paper, a concept of telescopic blade root is introduced to reduce fluctuate load induced by wind shear passively, and considering the blades as rigid assessment is operated, meanwhile aerodynamic model based on blade element method in order to analysis the aerodynamic load on NREL Phase VI reference based blade. The result shows that after introducing the equipment the blade fatigue load can be released, lengthening blade life
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