Low Earth Orbit (LEO) satellite mega-constellations promise ubiquitous network services to "unconnected" users. But their upcoming global routing for Earth will be unstable due to exhaustive topology updates between satellites and Earth, inside an orbital shell, and across heterogeneous orbital shells. In real LEO networks, these multi-dimensional dynamics are interleaved and complicated by chaotic orbital maneuvers and random failures. They are less predictable than most satellite routing proposals expect and threaten these proposals' availability, efficiency, or resiliency at scale. We propose SHORT, a Stable Hierarchical Orbital Routing Technique to decouple, localize, and mask multi-dimensional dynamics from operational LEO networks. SHORT takes a geographic paradigm to organize the LEO network as stable hierarchical routing domains, split heterogeneous LEO dynamics into each domain, mask them with domain-specific routing via orbital-geodetic coordinates, and localize adaptions to orbital maneuvers, random failures, and partial deployments. SHORT can work incrementally as a control-plane overlay to enhance existing LEO routing proposals. Our evaluations with the U.S. Space Surveillance Network datasets and prototype validate SHORT's near-optimal availability, efficiency, and resiliency in operational LEO networks.

In order to investigate the complex hydrodynamics and associated sediment movement resulting from the ship passages in heavy shipping traffic waterways, field measurements were performed in a heavy shipping traffic waterway. Based on the collected waves, flow velocity and water turbidity data, the analyses of the ship-induced hydrodynamics and associated sediment suspension phenomena were conducted. The low-frequency primary wave and high-frequency secondary wave were more pronounced for a barge and yacht in the wave structure, respectively, and contributed more to the flow velocity fluctuations and the bottom shear stress. The ship-induced bottom shear stress can cause significant suspended sediment concentration increase, and there is a correlation between the maximum suspended sediment concentration and maximum ship-induced drawdown height, which can provide a reference for the waterway management.

Jiangsu Province has the longest inland restricted waterway among all the provinces in China. Ecological revetment is the hot topic of current research on the river or channel regulation engineering in China. Evaluation of ecological restoration capability of revetment is an important part of revetment design as well as an effective basis of the revetment selection. Liudaxian channel of Jiangsu province is chosen for this study, an index system and method for evaluating of ecological restoration capability of revetment is established. By analyzing the mechanism and process of revetment impact on river ecosystems, indicators of ecological restoration capability and quantitative calculation method are proposed in revetment structure level. Based on the degree of influence of the indicator to river ecological function, instead of expert opinion, the set value iteration method was used to analyze the degree of influence of the indicator to river ecosystem, which made weight assignments objectively. Combining with gray relational analysis (GRA) method, the set value iteration based on ecological theory - gray correlation evaluation model was established, which achieved quantitative evaluation of the ecological restoration of revetment. The evaluating result of the projects shows that revetment of wood pile with ladder-sand tube + three-dimensional vegetation net is chosen as the recommended slope protection measure. The revetment ecological restoration evaluation model proposed in this paper with the advantages of objective, standardized and quantitative, offers an effective and feasible tool for designers and managers to evaluate the ecological restoration capability of revetment.

Low Earth Orbit (LEO) satellite network is undergoing an explosive expansion to enable high-speed Internet for numerous users anywhere on Earth. However, as a cyber-physical network, the LEO network's sustainable expansion is constrained by its harsh, crowded, and imbalanced physical environment. This position paper dives into two physical constraints for the LEO network scalability: the scale-out limit by satellite safety distances in crowded outer space, and the scale-up limit by the mismatch between the uniform LEO network capacity supply and geographically non-uniform global distribution of user demands. Traditional networking research pays less attention to these physical scaling limits, which may imply a call for a cyber-physical co-design to help the LEO network grow in the challenged space environment.