A software system and database for computer-aided diagnosis with thin-section computed tomographic (CT) images of the chest was designed and implemented. When presented with an unknown query image, the system uses pattern recognition to retrieve visually similar images with known diagnoses from the database. A preliminary validation trial was conducted with 11 volunteers who were asked to select the best diagnosis for a series of test images, with and without software assistance. The percentage of correct answers increased from 29% to 62% with computer assistance. This finding suggests that this system may be useful for computer-assisted diagnosis.

Structural coverage criteria are often used as an indicator of the thoroughness of testing, but complete satisfaction of a criterion is seldom achieved. When a software product is released with less than 100% coverage, testers are explicitly or implicitly assuming that executions satisfying the remaining test obligations (the residue) are either infeasible or occur so rarely that they have negligible impact on quality. Violation of this assumption indicates shortcomings in the testing process.Monitoring in the deployed environment, even in the beta test phase, is typically limited to error and sanity checks. Monitoring the residue of test coverage in actual use can provide additional useful information, but it is unlikely to be accepted by users unless its performance impact is very small. Experience with a prototype tool for residual test coverage monitoring of Java programs suggests that, at least for statement coverage, the simple strategy of removing all probes except those corresponding to the residue of coverage testing reduces execution overhead to acceptably low levels.

Many polyvariant program analyses have been studied in the 199Os, including &CFA, poly-BCFA, and the Cartesian product algorithm. The idea of polyvariance is to analyze functions more than once and thereby obtain better precision for each call site. In this paper we present the first formal relationship between polyvariant analysis and standard notions of type. In the spirit of Nielson and Nielson, we study a parameterized flow analysis which can be instantiated to the analyses of Agesen, Schmidt, and as a simple case also 0-CFA. Extended with safety checks, the ff ow analysis accepts and rejects programs, much like a type checker. We prove that if a program can be safety-checked by a finitary instantiation of the flow analysis, then it can also be typed in a type system with intersection types, union types, subtyping, and recursive types, but no universal or existential quantifiers. This provides a framework for designing and understanding combinations of flow analyses and type systems.

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