A Risk Evaluation Framework in System Control Subject to Sensor Degradation and Failure.

Sensor degradation and failure often undermine users' confidence in adopting a new data-driven decision-making model, especially in risk-sensitive scenarios. A risk assessment framework tailored to classification algorithms is introduced to evaluate the decision-making risks arising from sensor degradation and failures in such scenarios. The framework encompasses various steps, including on-site fault-free data collection, sensor failure data collection, fault data generation, simulated data-driven decision-making, risk identification, quantitative risk assessment, and risk prediction. Leveraging this risk assessment framework, users can evaluate the potential risks of decision errors under the current data collection status. Before model adoption, ranking risk sensitivity to sensor data provides a basis for optimizing data collection. During the use of decision algorithms, considering the expected lifespan of sensors enables the prediction of potential risks the system might face, offering comprehensive information for sensor maintenance. This method has been validated through a case study involving an access control.

The mechanism of soil nitrogen transformation under different biocrusts to warming and reduced precipitation: From microbial functional genes to enzyme activity.

Soil nitrogen (N) mineralization is a microbially-mediated biogeochemical process that is strongly influenced by changing climates. However, little information is available on the mechanisms behind the response of N mineralization to prolonged warming coupled with drought in soils covered by biocrusts. We used open top chambers to investigate the rate of soil N transformation (ammonification, nitrification and mineralization), enzyme activity and gene abundance in response to warming coupled with reduced precipitation over three years (2016-2018). Warming and drought significantly reduced the N transformation rate, extracellular enzyme activity, and gene abundance in moss-covered soil. For cyanobacteria-covered soil, however, it inhibited enzyme activity and increased the abundance of the nitrification-related genes and therefore nitrification rate. Our treatments had no obvious effects on N transformation and enzyme activity, but reduced gene abundance in bare soil. Biocrusts may facilitate N transformation while the degradation of moss crust caused by climate warming will dampen any regulating effect of biocrusts on the belowground microbial community. Furthermore, belowground microbial communities can mediate N transformation under ongoing warming and reduced precipitation by suppressing ammonification- and nitrification-related gene families, and by stimulating nitrification-related gene families involved in cyanobacteria-covered soil. This study provides a basis for identifying the functional genes involved in key processes in the N cycle in temperate desert ecosystems, and our results further highlight the importance of different biocrusts organisms in the N cycle in temperate deserts as Earth becomes hotter and drier.