10 research outputs found

    The Internet, populism, and deliberative democracy: A panel study of 167 countries from 2000 to 2018

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      The wide adoption of the Internet gave rise to populism, which is regarded as a critical threat to deliberative democracy. This paper was a cross-national panel study to explore the Internet’s populist impacts on deliberative democracy. It had two specific objectives. One was to examine whether or to what extent Internet penetration has populist impacts on deliberative dimensions, including reasoned justification, common good, respectful counterarguments, range of consultation, and engaged society. The other was to examine how Internet penetration moderates a country’s formal deliberative process, referring to the interaction among state institutions, the public sphere, and civil society. Using data from Varieties of Democracy (V-Dem) and the United Nations, we run panel analyses with a sample of 3,173 units in 167 countries from 2000 to 2018. The results showed that Internet penetration increased calls for the common good, disrespected counterarguments, narrowed the range of consultation, and expanded engagement in public deliberation. In addition, Internet penetration strengthened the effects of public sphere on reasoned justification and range of consultation, but weakened the effects of civil society on reasoned justification, common good, respectful counterarguments, and range of consultation

    Efficient Routing Protection Algorithm Based on Optimized Network Topology

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    Network failures are unavoidable and occur frequently. When the network fails, intra-domain routing protocols deploying on the Internet need to undergo a long convergence process. During this period, a large number of messages are discarded, which results in a decline in the user experience and severely affects the quality of service of Internet Service Providers (ISP). Therefore, improving the availability of intra-domain routing is a trending research question to be solved. Industry usually employs routing protection algorithms to improve intra-domain routing availability. However, existing routing protection schemes compute as many backup paths as possible to reduce message loss due to network failures, which increases the cost of the network and impedes the methods deployed in practice. To address the issues, this study proposes an efficient routing protection algorithm based on optimized network topology (ERPBONT). ERPBONT adopts the optimized network topology to calculate a backup path with the minimum path coincidence degree with the shortest path for all source purposes. Firstly, the backup path with the minimum path coincidence with the shortest path is described as an integer programming problem. Then the simulated annealing algorithm ERPBONT is used to find the optimal solution. Finally, the algorithm is tested on the simulated topology and the real topology. The experimental results show that ERPBONT effectively reduces the path coincidence between the shortest path and the backup path, and significantly improves the routing availability

    Tree Line Identification and Dynamics under Climate Change in Wuyishan National Park Based on Landsat Images

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    The alpine tree line ecotone, reflecting interactions between climate and ecology, is very sensitive to climate change. To identify tree line responses to climate change, including intensity and local variations in tree line advancement, the use of Landsat images with long-term data series and fine spatial resolution is an option. However, it is a challenge to extract tree line data from Landsat images due to classification issues with outliers and temporal inconsistency. More importantly, direct classification results in sharp boundaries between forest and non-forest pixels/segments instead of representing the tree line ecotone (three ecological regions—tree species line, tree line, and timber line—are closely related to the tree line ecotone and are all significant for ecological processes). Therefore, it is important to develop a method that is able to accurately extract the tree line from Landsat images with a high temporal consistency and to identify the appropriate ecological boundary. In this study, a new methodology was developed based on the concept of a local indicator of spatial autocorrelation (LISA) to extract the tree line automatically from Landsat images. Tree line responses to climate change from 1987 to 2018 in Wuyishan National Park, China, were evaluated, and topographic effects on local variations in tree line advancement were explored. The findings supported the methodology based on the LISA concept as a valuable classifier for assessing the local spatial clusters of alpine meadows from images acquired in nongrowing seasons. The results showed that the automatically extracted line from Landsat images was the timber line due to the restriction in spatial autocorrelation. The results also indicate that parts of the tree line in the study area shifted upward vertically by 50 m under a 1 °C temperature increase during the period from 1987 to 2018, with local variations influenced by slope, elevation, and interactions with aspect. Our study contributes a novel result regarding the response of the alpine tree line to global warming in a subtropical region. Our method for automatic tree line extraction can provide fundamental information for ecosystem managers

    RP-Ring: A Heterogeneous Multi-FPGA Accelerator

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    To reduce the cost of designing new specialized FPGA boards as direct-summation MOND (Modified Newtonian Dynamics) simulator, we propose a new heterogeneous architecture with existing FPGA boards, which is called RP-ring (reconfigurable processor ring). This design can be expanded conveniently with any available FPGA board and only requires quite low communication bandwidth between FPGA boards. The communication protocol is simple and can be implemented with limited hardware/software resources. In order to avoid overall performance loss caused by the slowest board, we build a mathematical model to decompose workload among FPGAs. The dividing of workload is based on the logic resource, memory access bandwidth, and communication bandwidth of each FPGA chip. Our accelerator can achieve two orders of magnitude speedup compared with CPU implementation

    RP-Ring: A Heterogeneous Multi-FPGA Accelerator

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    Seasonal variations in the mechanisms of understory herb diversity in a temperate forest in Northeast China

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    Herbaceous plants contribute greatly to plant diversity and play an important role in regulating the structure and functioning of forest ecosystems. Comparing with woody species, herbs exhibit higher sensitivity to seasonal changes from spring-growth to autumn-mortality. Despite extensive research on understory herb diversity (e.g., abundance and richness) in forests, how the underlying mechanisms change across seasons remain unclear, especially in temperate forests. We explored the seasonal dynamics of herb diversity (here abundance and richness) by surveying herbs of 174 quadrats (1 m × 1 m) in a 25-ha (500 m × 500 m) temperate forest in spring, summer, and autumn of 2022, respectively. We examined the effects of overstory trees (diversity, composition, and three-dimensional (3D) structural complexity detected by LiDAR), topography (elevation, slope, and aspect), and microsite conditions (light availability, soil nutrients, and soil water content) on herb diversity in different seasons. We found a similar seasonal pattern for herb abundance and richness, i.e., both decreased from spring to summer and then to autumn, but the driving mechanisms differed remarkably across seasons. Specifically, the importance of overstory trees, topography, and microsite conditions on herb abundance vs. richness varied inversely across seasons. For herb abundance, the importance of overstory trees (primarily 3D structural complexity) increased from spring to autumn, while the importance of topography decreased. Conversely, for herb richness, the importance of overstory trees decreased from spring to autumn, while the importance of topography increased. Microsite conditions governed spatial variations of herb abundance in all seasons but only in autumn for herb richness, with importance of soil nutrients remaining relatively constant while that of soil water content and light availability changed greatly across seasons. Our results demonstrate substantial seasonal variations in driving mechanisms of herb diversity in the temperate forest. These differentiated responses of herb abundance and richness to different drivers across seasons further highlight the significance of considering seasonal variations of the mechanisms underlying understory plant diversity in forest biodiversity conservation
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