Decontamination of Mutual Contamination Models

Many machine learning problems can be characterized by mutual contamination models. In these problems, one observes several random samples from different convex combinations of a set of unknown base distributions and the goal is to infer these base distributions. This paper considers the general setting where the base distributions are defined on arbitrary probability spaces. We examine three popular machine learning problems that arise in this general setting: multiclass classification with label noise, demixing of mixed membership models, and classification with partial labels. In each case, we give sufficient conditions for identifiability and present algorithms for the infinite and finite sample settings, with associated performance guarantees.Comment: Published in JMLR. Subsumes arXiv:1602.0623

Hop Crowning Trial

Downy mildew has been identified as the primary pathogen plaguing our northeastern hop yards. This disease causes reduced yield, poor hop quality, and can cause the plant to die in severe cases. Control measures that reduce disease infection and spread while minimizing the impact on the environment, are desperately needed for the region. Mechanical control is one means to reduce downy mildew pressure in hop yards. Scratching, pruning, or crowning is a practice initiated in the early spring when new growth has just emerged from the soil

CCi digital futures 2014: the Internet in Australia

This report presents findings from the third survey of the Australian component of the World Internet Project. The survey was conducted in late 2013. This research is a project of the ARC Centre of Excellence for Creative Industries and Innovation at the Swinburne Institute for Social Research, Swinburne University of Technology. This report provides an overview of the study, presenting a broad picture of the Internet in Australia, with comparisons to our earlier 2007, 2009 and 2013 studies, and to the international findings of our partners in the World Internet Project. At the end of each section we have added some further analysis, examining aspects of the Australian data in more detail, and providing some international context using results from the findings of our international research partners. &nbsp

Hop Optimal Irrigation Trial

Hops reportedly use about 610 to 715 mm (24 to 28 inches) of water per year (Evans 2003). Rainfall can contribute to this total, however, due to climatic variability, it is important that hops are irrigated regularly to combat moisture stress. Moisture deficit during the hop growing season has been shown to cause reductions in hop cone yield (Hnilickova et al. 2009). Irrigation systems can help to alleviate some of the potential drought stress, but timing of water application is just as important as the amount of water hops are receiving. Hops require the majority of their water in the critical period between training and flowering for optimal vegetative growth. The hop yard is irrigated through a well-fed drip irrigation system, which delivers 3000 gal ac-1 each week, beginning in late May. Over the 14-week irrigation period, this equates to 1.54 inches of water, or 0.11 inches each week, which is well below the 23.5 inches required, adjusting for potential evapotranspiration. The goal of this project was to evaluate differences in yield, insect pests, and disease presence between plants at the Borderview Research Farm that were watered at the optimal level, and plants that were irrigated at the level sustained by the on-farm well

Hop Biofungicide Trial

Downy mildew has been identified as the primary pathogen plaguing northeastern hop yards. This disease causes reduced yield, poor hop quality, and, in severe cases, plant death. Control measures that reduce disease incidence and have a low environmental impact are desperately needed for the region. Regular application of protectant fungicide sprays is an effective method for managing downy mildew pressure in hop yards. However, regular chemical applications can lead to residual toxicity in the soil and have a negative effect on beneficial organisms. Extended use of protectant and curative fungicides can also lead to pathogen resistance. The goal of this project was to evaluate the efficacy of organic approved biofungicides with a variety of active ingredients for control of downy mildew in hops