Predicting Accurate and Actionable Static Analysis Warnings: An Experimental Approach

Static analysis tools report software defects that may or may not be detected by other verification methods. Two challenges complicating the adoption of these tools are spurious false positive warnings and legitimate warnings that are not acted on. This paper reports automated support to help address these challenges using logistic regression models that predict the foregoing types of warnings from signals in the warnings and implicated code. Because examining many potential signaling factors in large software development settings can be expensive, we use a screening methodology to quickly discard factors with low predictive power and cost-effectively build predictive models. Our empirical evaluation indicates that these models can achieve high accuracy in predicting accurate and actionable static analysis warnings, and suggests that the models are competitive with alternative models built without screening.

Actinocyclus ingens var. nodus : a New, Stratigraphically Useful Diatom of the Circum-North Pacific

Actinocyclus ingens var, nodus Baldauf, n, var., is a morphologically distinct variety of the Miocene diatom A. ingens Ranray. The last occurrence of this new taxon approximates the top of the lower Middle Miocene Denticula Iauta Zone in the circum-North Pacific. Its first occurrence appears to be in the lower part of the D. fauta zone and possibly lies close to the Lower Miocene-Middle Miocene boundary.