Search for: All records

Given sensor units distributed throughout an environment, we consider the problem of consolidating readings into a single coherent view when sensors wish to limit knowledge of their specific readings. Standard fusion methods make no guarantees about what curious participants may learn. For applications where privacy guarantees are required, we introduce a fusion approach that limits what can be inferred. First, it forms an aggregate stream, oblivious to the underlying sensor data, and then evaluates that stream on a combinatorial filter. This is achieved via secure multi-party computation techniques built on cryptographic primitives, which we extend and apply to the problem of fusing discrete sensor signals. We prove that the extensions preserve security under the model of semi-honest adversaries. Also, for a simple target tracking case study, we examine a proof-of-concept implementation: analyzing the (empirical) running times for components in the architecture and suggesting directions for future improvement. 

With over 65% of agronomic crops under no-till in Pennsylvania, herbicides are relied on for weed management. To lessen the environmental impact and selection pressure for herbicide resistance, we conducted a nine-year experiment to test herbicide reduction practices in a dairy crop rotation at Rock Springs, PA. The rotation included soybean (Glycine max L.) – corn (Zea mays L.) - 3-year alfalfa (Medicago sativa L.) - canola (Brassica napus L.). The following practices were used to reduce herbicide inputs: i. banding residual herbicides over corn and soybean rows and using high-residue inter-row cultivation; ii. seeding a small grain companion crop with alfalfa; iii. plowing once in six years to terminate the perennial forage. These practices were compared with standard herbicide-based weed management (SH) in continuous no-till. We hypothesized: i. There would be more weed biomass in the reduced herbicide treatment (RH), ii. leading to more weeds in RH over time, but iii. the added weed pressure would not affect yield iv. or differences in net return. We sampled weed biomass in soybean, corn, and the first two forage years. In corn and soybean, weed biomass was often greater in RH than SH and increased over the years in the RH treatments. In the forage, weed biomass did not always differ between treatments. Yield and differences in net return were similar in most crops and years. Results suggest that weed management with reduced herbicide inputs supplemented with an integrated approach can be effective but may lead to more weeds over time.