10,263 research outputs found

    The association between resilience and survival among Chinese elderly

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    Based on the unique longitudinal data of the elderly aged 65+ with a sufficiently large sub-sample of the oldest-old aged 85+ from the Chinese Longitudinal Healthy Longevity Survey, we construct a resilience scale with 7 indicators for the Chinese elderly, based on the framework of the Connor-Davidson Resilience Scale. Cox proportional hazards regression model estimates show that, after controlling for socio-demographic characteristics and initial health status, the total resilience score and most factors of the resilience scale are significantly associated with reduced mortality risk among the young-old and oldest-old. Although the causal mechanisms remain to be investigated, effective measures to promote resilience are likely to have a positive effect on longevity of the elderly in China.China, healthy life expectancy, mortality risk, residence, survival

    One More Weight is Enough: Toward the Optimal Traffic Engineering with OSPF

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    Traffic Engineering (TE) leverages information of network traffic to generate a routing scheme optimizing the traffic distribution so as to advance network performance. However, optimize the link weights for OSPF to the offered traffic is an known NP-hard problem. In this paper, motivated by the fairness concept of congestion control, we firstly propose a new generic objective function, where various interests of providers can be extracted with different parameter settings. And then, we model the optimal TE as the utility maximization of multi-commodity flows with the generic objective function and theoretically show that any given set of optimal routes corresponding to a particular objective function can be converted to shortest paths with respect to a set of positive link weights. This can be directly configured on OSPF-based protocols. On these bases, we employ the Network Entropy Maximization(NEM) framework and develop a new OSPF-based routing protocol, SPEF, to realize a flexible way to split traffic over shortest paths in a distributed fashion. Actually, comparing to OSPF, SPEF only needs one more weight for each link and provably achieves optimal TE. Numerical experiments have been done to compare SPEF with the current version of OSPF, showing the effectiveness of SPEF in terms of link utilization and network load distribution

    Segregation by Race in Public Schools Retrospect and Prospect

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    Solar energy conversion has been intensively studied in past decades and has been shown to be greatly effective for solving the serious environmental pollution and energy shortage problems. Photoelectrocatalysis and photovoltaics have been considered as the two main approaches for solar energy conversion and utilization, which are generally involved with nanostructured materials and/or catalytic processes, greatly affecting the efficiencies for solar energy conversion. Then, it is necessary to understand the relationship between the physical and chemical properties of nanomaterials and their performances for solar energy conversion. It is also important to explore the fundamentals in catalytic processes for solar energy conversion and make breakthrough in design and synthesis of nanomaterials or nanostructures, characterization of material properties, and performance of novel devices and systems. The aim of this special issue is to present some recent progress in the field of advanced catalysis and nanostructure design for solar energy conversion. A brief summary of all accepted papers is provided below
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