124 research outputs found

    Estimating a Large Drive Time Matrix between Zip Codes in the United States: A Differential Sampling Approach

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    Estimating a massive drive time matrix between locations is a practical but challenging task. The challenges include availability of reliable road network (including traffic) data, programming expertise, and access to high-performance computing resources. This research proposes a method for estimating a nationwide drive time matrix between ZIP code areas in the U.S.--a geographic unit at which many national datasets such as health information are compiled and distributed. The method (1) does not rely on intensive efforts in data preparation or access to advanced computing resources, (2) uses algorithms of varying complexity and computational time to estimate drive times of different trip lengths, and (3) accounts for both interzonal and intrazonal drive times. The core design samples ZIP code pairs with various intensities according to trip lengths and derives the drive times via Google Maps API, and the Google times are then used to adjust and improve some primitive estimates of drive times with low computational costs. The result provides a valuable resource for researchers

    Patch Is Not All You Need

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    Vision Transformers have achieved great success in computer visions, delivering exceptional performance across various tasks. However, their inherent reliance on sequential input enforces the manual partitioning of images into patch sequences, which disrupts the image's inherent structural and semantic continuity. To handle this, we propose a novel Pattern Transformer (Patternformer) to adaptively convert images to pattern sequences for Transformer input. Specifically, we employ the Convolutional Neural Network to extract various patterns from the input image, with each channel representing a unique pattern that is fed into the succeeding Transformer as a visual token. By enabling the network to optimize these patterns, each pattern concentrates on its local region of interest, thereby preserving its intrinsic structural and semantic information. Only employing the vanilla ResNet and Transformer, we have accomplished state-of-the-art performance on CIFAR-10 and CIFAR-100, and have achieved competitive results on ImageNet

    Characterization of a multidrug-resistant porcine Klebsiella pneumoniae sequence type 11 strain coharboring blaKPC-2 and fosA3 on two novel hybrid plasmids

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    The occurrence of carbapenemase-producing Enterobacteriaceae (CPE) poses a considerable risk for public health. The gene for Klebsiella pneumoniae carbapenemase-2 (KPC-2) has been reported in many countries worldwide, and KPC-2-producing strains are mainly of human origin. In this study, we identified two novel hybrid plasmids that carry either blaKPC-2 or the fosfomycin resistance gene fosA3 in the multiresistant K. pneumoniae isolate K15 of swine origin in China. The blaKPC-2-bearing plasmid pK15-KPC was a fusion derivative of an IncF33:A−:B− incompatibility group (Inc) plasmid and chromosomal sequences of K. pneumoniae (CSKP). A 5-bp direct target sequence duplication (GACTA) was identified at the boundaries of the CSKP, suggesting that the integration might have been due to a transposition event. The blaKPC-2 gene on pK15-KPC was in a derivative of ΔTn6296-1. The multireplicon fosA3-carrying IncN-IncR plasmid pK15-FOS also showed a mosaic structure, possibly originating from a recombination between an epidemic fosA3-carrying pHN7A8-like plasmid and a pKPC-LK30-like IncR plasmid. Stability tests demonstrated that both novel hybrid plasmids were stably maintained in the original host without antibiotic selection but were lost from the transformants after approximately 200 generations. This is apparently the first description of a porcine sequence type 11 (ST11) K. pneumoniae isolate coproducing KPC-2 and FosA3 via pK15-KPC and pK15-FOS, respectively. The multidrug resistance (MDR) phenotype of this high-risk K. pneumoniae isolate may contribute to its spread and its persistence

    Atomic Sn–enabled high-utilization, large-capacity, and long-life Na anode

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    Constructing robust nucleation sites with an ultrafine size in a confined environment is essential toward simultaneously achieving superior utilization, high capacity, and long-term durability in Na metal-based energy storage, yet remains largely unexplored. Here, we report a previously unexplored design of spatially confined atomic Sn in hollow carbon spheres for homogeneous nucleation and dendrite-free growth. The designed architecture maximizes Sn utilization, prevents agglomeration, mitigates volume variation, and allows complete alloying-dealloying with high-affinity Sn as persistent nucleation sites, contrary to conventional spatially exposed large-size ones without dealloying. Thus, conformal deposition is achieved, rendering an exceptional capacity of 16 mAh cm−2 in half-cells and long cycling over 7000 hours in symmetric cells. Moreover, the well-known paradox is surmounted, delivering record-high Na utilization (e.g., 85%) and large capacity (e.g., 8 mAh cm−2) while maintaining extraordinary durability over 5000 hours, representing an important breakthrough for stabilizing Na anode

    Endoscopic Surgery for Supratentorial Deep Cavernous Malformation Adjacent to Cortical Spinal Tract: Preliminary Experience and Technical Note

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    In this study, we aimed to introduce a technical note and to explore the efficacy of endoscopic surgery combined with diffusion tensor imaging (DTI) navigation for supratentorial deep cerebral cavernous malformations (CCM). A prospectively maintained database of CCM patients was reviewed to identify all CCM patients treated by endoscopic surgery. The sagittal T1-weighted anatomical magnetic resonance imaging (MRI) and DTI were acquired before surgery. Endoscopic surgery was planned and performed based on preoperative DTI images and intraoperative DTI navigation. All patients were followed up more than 6 months. Motor function deficit and modified Rankin scale (mRS) scores were documented on follow-up. A final mRS score of 0–2 was considered a good outcome, and a final mRS score >2 was considered a poor outcome. Second DTI and 3DT1 were performed at 3 months after surgery. We tracked the ipsilateral corticospinal tract (CST) on pre- and postoperative DTI images. The overall mean FA values and the number of fibers of tracked CST were compared on pre- and postoperative DTI images. Risk factors associated with motor deficits and poor outcomes were analyzed. Seven patients with deep CCM and treated by endoscopic surgery were enrolled in this study. The mean value of preoperative mRS was 1.5 ± 0.98, but that score recovered to 0.86 ± 1.22 3 months later. The mRS scores were improved significantly according to statistical analysis (p = 0.012). According to the Spearman non-parametric test, only the fiber number of ipsilateral CST on postoperative DTI was significantly associated with muscle strength 6 months after surgery (p = 0.032). Compared with preoperative CST characteristics on DTI, the change of FA value (p = 0.289) and fiber number (p = 0.289) of ipsilateral CST on postoperative DTI was not significant It meant that the CST was protected during endoscopic surgery. Endoscopic surgery based on DTI navigation might be an effective method to protect fiber tracts in supratentorial deep CCM patients and improve long-term outcomes. However, more studies and cases are needed to confirm our findings

    Revealed Comparative Economies of Scope and Development Index

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    In this note, we attempt to construct some summary statistic to measure economic development and make comparisons across countries. A development index is defined in terms of both "scale" and "scope". "Scale" is measured by output per capita. "Scope" is measured by revealed comparative economies of scope, which in turn is measured by the ratio of the variety of exports over the variety of imports for a country. Using purchasing power parity and the Standard International Trade Classification, we have computed the development index for forty countries

    Utility Analysis on Supply of Rural Public Policies in North Bay Economic Zone

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    From analysis on internal and external motive forces of development in North Bay Economic Zone, it indicates that public policies, as basic methods of government intervening against social and economic activities, are fundamental public goods produced by government. Effective supply of public policies brings rural economic growth, environmental protection and sustainable development, which greatly stimulates rural consumption, expands domestic demand and spurs economic growth, showing significant “multiplier effect”. In this situation, this paper studies conditions for rural economic development and social transformation of the North Bay Economic Zone. Results show that social and economic development of rural areas of the North Bay Economic Zone needs scientific, reasonable and effective “public policies”

    Two-Round Diagnosability Measures for Multiprocessor Systems

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    In a multiprocessor system, as a key measure index for evaluating its reliability, diagnosability has attracted lots of attentions. Traditional diagnosability and conditional diagnosability have already been widely discussed. However, the existing diagnosability measures are not sufficiently comprehensive to address a large number of faulty nodes in a system. This article introduces a novel concept of diagnosability, called two-round diagnosability, which means that all faulty nodes can be identified by at most a one-round replacement (repairing the faulty nodes). The characterization of two-round t-diagnosable systems is provided; moreover, several important properties are also presented. Based on the abovementioned theories, for the n-dimensional hypercube Qn, we show that its two-round diagnosability is n2+n/2, which is n+1/2 times its classic diagnosability. Furthermore, a fault diagnosis algorithm is proposed to identify each node in the system under the PMC model. For Qn, we prove that the proposed algorithm is the time complexity of On2n

    Assessing the Role of Policies on Land-Use/Cover Change from 1965 to 2015 in the Mu Us Sandy Land, Northern China

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    Policy has long been considered one of the major driving forces for land-use/cover change. However, research on the interactions between land-use/cover change (LUCC) and relevant policies remains limited. The agropastoral ecotone is a typical area of policy implementation and LUCC. Therefore, this study integrates the use of multisource and multiresolution remote sensing and topographic and field-based datasets for the case of the Mu Us Sandy Land (MUSL) in northern China. The research aim was to quantify LUCC from 1965 to 2015 and describe the relationship between policy changes and land-use types during three stages: the stage of the Great Cultural Revolution, the stage of the modernization of the economy, and the stage of the Great Ecological Project. The results indicated that land use was affected by different national policies because of the national approach to land use during different periods. In the stage of the Great Cultural Revolution, the amount of cultivated land increased, and the environment deteriorated under the influence of leftists. In the stage of the modernization of the economy, vegetation coverage improved after the initial damage, and cultivated and artificial surfaces also increased. In the stage of the Great Ecological Project, cultivated land and unused land decreased, and woodland and sparse vegetation increased with the implementation of the Grain for Green Project (GGP). However, cultivated land increased but wood land and sparse vegetation decreased significantly by the end of the GGP. The coverage of artificial surfaces increased and grasslands decreased due to the encroachment of artificial surfaces into grasslands
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