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Full-Text Articles in Physical Sciences and Mathematics
Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Tholl
Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Tholl
Dissertations and Theses
Machine learning has been used as a tool to model transpiration for individual sites, but few models are capable of generalizing to new locations without calibration to site data. Using the global SAPFLUXNET database, 95 tree sap flow data sites were grouped using three clustering strategies: by biome, by tree functional type, and through use of a k-means unsupervised clustering algorithm. Two supervised machine learning algorithms, a random forest algorithm and a neural network algorithm, were used to build machine learning models that predicted transpiration for each cluster. The performance and feature importance in each model were analyzed and compared …
Patterns Of Dissolved Methane In Groundwater And Its Contribution To Emissions Inventories, Amanda E. Campbell
Patterns Of Dissolved Methane In Groundwater And Its Contribution To Emissions Inventories, Amanda E. Campbell
Dissertations - ALL
The Marcellus Shale is the largest shale gas play in the U.S. production of natural gas using high-volume hydraulic fracturing (HVHF) and production is prevalent throughout the play except in New York (NY), where it is currently banned. High concentrations of methane, the main component of natural gas, in groundwater, as well as its presence in the atmosphere, can have negative consequences. In this dissertation, three aspects of this issue are explored: 1) how and why naturally-occurring methane concentrations vary through time; 2) how elevated naturally-occurring methane concentrations in domestic water wells can be predicted from commonly observed well characteristics; …
Assessing Machine Learning Utility In Predicting Hydrologic And Nitrate Dynamics In Karst Agroecosystems, Timothy Mcgill
Assessing Machine Learning Utility In Predicting Hydrologic And Nitrate Dynamics In Karst Agroecosystems, Timothy Mcgill
Theses and Dissertations--Biosystems and Agricultural Engineering
Seasonal hypoxia in the Gulf of Mexico and harmful algal blooms experienced in many inland freshwater bodies is partially driven due to excessive nitrogen loading seen from agricultural watersheds. Within the Mississippi/Atchafalaya River Basin, many areas are underlain with karst features, and efforts to reduce nitrogen contributions from these areas have had varying success, due to lacking a complete understanding of nutrient dynamics in karst agricultural systems. To improve the understanding of nitrogen cycling in these systems, 35 months of high resolution in situ water quality and atmospheric data were collected and fed into a two-hidden layer extreme learning machine …