397 research outputs found

    Using a watershed approach to identify protection and restoration actions in the Blackjack Creek watershed, Kitsap County, Washington

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    The Blackjack Creek watershed, 12.3 square miles in eastern Kitsap County, is among the largest and most productive salmon watersheds in the south Kitsap subregion. The watershed supports genetically-distinct summer and late fall runs of chum salmon, and coho and Chinook, as well as steelhead and cutthroat trout. Historic and current land uses in many parts of the Blackjack Creek watershed have substantially altered processes that drive ecosystem functions. The Suquamish Tribe conducted a watershed assessment to identify critical ecosystem components and key ecological attributes (KEAs), their current status, and human-caused pressures on KEAs. The goal was to build a plan, including strategies and actions, to protect and restore watershed, riparian, floodplain and stream processes and habitat functions for salmonids. The assessment includes a review of existing research, local studies, spatial data (GIS), and field data on freshwater and estuarine habitats and salmonid populations. Hydrologic patterns are identified and analyzed using “down-scaled” spatial data from Ecology’s Puget Sound Watershed Characterization Project to understand water flow processes in the subbasins of the watershed. These data are consolidated in a comprehensive assessment of human induced pressures and ecosystem stressors. The 13 strategies and 45 recommended actions in the plan address these specific pressures and are intended to protect and restore watershed processes and habitats. Strategies and actions are evaluated using a prioritization framework based on the principles of process-based restoration and climate change considerations. The plan will be used by the Tribe and project partners including the City of Port Orchard, Kitsap County, Kitsap Conservation District, Great Peninsula Conservancy and others to implement future protection and restoration in the Blackjack Creek watershed

    Sui Lutris: A Blockchain Combining Broadcast and Consensus

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    Sui Lutris is the first smart-contract platform to sustainably achieve sub-second finality. It achieves this significant decrease in latency by employing consensusless agreement not only for simple payments but for a large variety of transactions. Unlike prior work, Sui Lutris neither compromises expressiveness nor throughput and can run perpetually without restarts. Sui Lutris achieves this by safely integrating consensuless agreement with a high-throughput consensus protocol that is invoked out of the critical finality path but makes sure that when a transaction is at risk of inconsistent concurrent accesses its settlement is delayed until the total ordering is resolved. Building such a hybrid architecture is especially delicate during reconfiguration events, where the system needs to preserve the safety of the consensusless path without compromising the long-term liveness of potentially misconfigured clients. We thus develop a novel reconfiguration protocol, the first to show the safe and efficient reconfiguration of a consensusless blockchain. Sui Lutris is currently running in production as part of a major smart-contract platform. Combined with the Move Programming language it enables the safe execution of smart contracts that expose objects as a first-class resource. In our experiments Sui Lutris achieves latency lower than 0.5 seconds for throughput up to 5,000 certificates per second (150k ops/s with bundling), compared to the state-of-the-art real-world consensus latencies of 3 seconds. Furthermore, it gracefully handles validators crash-recovery and does not suffer visible performance degradation during reconfiguration

    Lunar Mining: Designing a Robust Robotic Mining System

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    The annual NASA Robotic Mining Challenge: Lunabotics tasks teams with building robots capable of traversing and mining simulated Lunar terrain. The competition goal is to utilize automation and sensing alongside mechanical systems to harvest icy regolith (gravel) from beneath the satellite’s surface. This year, Utah Student Robotics sought to improve upon the design from last year. The 2019-2020 rover is based on proven NASA concepts, such as the RASSOR 2.0 digging drum, and the Rocker-Bogie mobility platform