15 research outputs found

    Decentralized Complete Dictionary Learning via ℓ4\ell^{4}-Norm Maximization

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    With the rapid development of information technologies, centralized data processing is subject to many limitations, such as computational overheads, communication delays, and data privacy leakage. Decentralized data processing over networked terminal nodes becomes an important technology in the era of big data. Dictionary learning is a powerful representation learning method to exploit the low-dimensional structure from the high-dimensional data. By exploiting the low-dimensional structure, the storage and the processing overhead of data can be effectively reduced. In this paper, we propose a novel decentralized complete dictionary learning algorithm, which is based on ℓ4\ell^{4}-norm maximization. Compared with existing decentralized dictionary learning algorithms, comprehensive numerical experiments show that the novel algorithm has significant advantages in terms of per-iteration computational complexity, communication cost, and convergence rate in many scenarios. Moreover, a rigorous theoretical analysis shows that the dictionaries learned by the proposed algorithm can converge to the one learned by a centralized dictionary learning algorithm at a linear rate with high probability under certain conditions

    Public health insurance and cancer‐specific mortality risk among patients with breast cancer: A prospective cohort study in China

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    We thank all staff members working on the Breast Cancer Information Management System (BCIMS) for their contributions to data collection and management. We also thank Dr Bo Fu, Mr Yan Li and Mr Pei Liu at the University of Electronic Science and Technology of China for data cleaning and zip code mapping. Our study was supported by the Key Research and Development Project of Sichuan Province of China (grant number: 2017SZ00005) and Swedish Research Council (grant number: 2018‐00648).Little is known about how health insurance policies, particularly in developing countries, influence breast cancer prognosis. Here, we examined the association between individual health insurance and breast cancer-specific mortality in China. We included 7436 women diagnosed with invasive breast cancer between 2009 and 2016, at West China Hospital, Sichuan University. The health insurance plan of patient was classified as either urban or rural schemes and was also categorized as reimbursement rate (ie, the covered/total charge) below or above the median. Breast cancer-specific mortality was the primary outcome. Using Cox proportional hazards models, we calculated hazard ratios (HRs) for cancer-specific mortality, contrasting rates among patients with a rural insurance scheme or low reimbursement rate to that of those with an urban insurance scheme or high reimbursement rate, respectively. During a median follow-up of 3.1 years, we identified 326 deaths due to breast cancer. Compared to patients covered by urban insurance schemes, patients covered by rural insurance schemes had a 29% increased cancer-specific mortality (95% CI 0%-65%) after adjusting for demographics, tumor characteristics and treatment modes. Reimbursement rate below the median was associated with a 42% increased rate of cancer-specific mortality (95% CI 11%-82%). Every 10% increase in the reimbursement rate is associated with a 7% (95% CI 2%-12%) reduction in cancer-specific mortality risk, particularly in patients covered by rural insurance schemes (26%, 95% CI 9%-39%). Our findings suggest that underinsured patients face a higher risk of breast cancer-specific mortality in developing countries.VetenskapsrådetPeer Reviewe

    MANUFACTURING AND INTERFACIAL BONDING BEHAVIOR OF EVA FILM REINFORCED FLEXIBLE DECORATIVE VENEER

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    Polyethylene film reinforced flexible decorative veneer has attracted wide attention. However, its curling deformation has not been well solved due to the high processing temperature. Ethylene-vinyl acetate copolymer (EVA) has lower melting temperature and better flexibility than polyethylene. In this work, EVA film was selected to enhance Manchurian ash (Fraxinus mandshurica) aimed at preparing flexible decorative veneer with high strength and low curling degree. Box-Behnken experimental design method was applied to determine the optimum processing parameters. The secondary overlaying performance of the flexible veneer was evaluated. Under optimum conditions the EVA reinforced veneer obtained a maximum transverse tensile strength of 2.42 MPa. EVA can form a continuous interface with the veneer, which was helpful to improve the flexibility of the veneer. Curling degree of the EVA film reinforced veneer was far less than that of the polyethylene reinforced veneer even at the same processing temperature. EVA reinforced flexible veneer was good to be used to decorate wood-based panels without additional adhesives. Both immersion peel strength and surface bonding strength of the prepared decorative panel can meet the requirements of GB/T 15104-2006.

    Karyotypes of 10 Anuran Species from the Qinghai–Tibetan Plateau

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    The Qinghai–Tibet Plateau (QTP) is the highest and largest mountain plateau in the world, which has become a focus area of amphibian biodiversity research and conservation, depending on its large number of endemic and threatened species. Among the 58 families of Anura, only a few species of four families (Megophryidae, Bufonidae, Dicroglossidae, Ranidae) are distributed in QTP. Revealing the genetic diversity of these species is crucial for research on their environmental adaptability and biodiversity conservation. Chromosome rearrangements are a critical source of genetic variation, which is recognized as a driver of speciation, providing the genetic material for differentiation and environmental adaptation of amphibians. Here, we identified the karyotypes of 10 species of the above families from the QTP. The karyotypes of these species were obtained from new sites that were not previously reported. Among them, the karyotypes of D. himalayanus and tetraploid B. zamdaensis were reported for the first time. In particular, the ploidy of B. zamdaensis from Zanda, China, was found to be distinctly different from the ploidy from Spiti River, India. This indicates that they have presented species differentiation and supports the multiple and complicated polyploidization events in the Bufotes toads. Furthermore, the different locations of the secondary constriction between the Weixi and Zhongdian populations of O. xiangchengensis support that there is a karyotypic variation between the two subspecies (O. xiangchengensis xiangchengensis vs. O. xiangchengensis deqinicus). A series of chromosomal variations may have facilitated the rapid evolution of amphibians in the QTP, and our study will provide support for further research on amphibian genetic diversity and biodiversity conservation

    Characteristics of hydrogen and methane production from cornstalks by an augmented two- or three-stage anaerobic fermentation process

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    This paper presents the co-production of hydrogen and methane from cornstalks by a two- or three-stage anaerobic fermentation process augmented with effective artificial microbial community. Two-stage fermentation by using the anaerobic sludge and DGGE analysis showed that effective and stable strains should be introduced into the system. We introduced Enterobacter aerogens or Clostridium paraputrificum into the hydrogen stage, and C. poraputrificum was proven to be more effective. In the three-stage process consisting of the improved hydrolysis, hydrogen and methane production stages, the highest soluble sugars (0.482 kg/kg cornstalks) were obtained after the introduction of Clostridium thermocellum in the hydrolysis stage, under the thermophilic (55 degrees C) and acidic (pH 5.0) conditions. Hydrolysates from I kg of cornstalks could produce 2.61 mol (63.71) hydrogen by augmentation with C. parciputrificum and 4.69 mol (114.61) methane by anaerobic granular sludge, corresponding to 54.1% energy recovery. (C) 2009 Elsevier Ltd. All rights reserved
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