Testing for Software Safety

This research focuses on testing whether or not the hazardous conditions identified by design-level fault tree analysis will occur in the target implementation. Part 1: Integrate fault tree models into functional specifications so as to identify testable interactions between intended behaviors and hazardous conditions. Part 2: Develop a test generator that produces not only functional tests but also safety tests for a target implementation in a cost-effective way. Part 3: Develop a testing environment for executing generated functional and safety tests and evaluating test results against expected behaviors or hazardous conditions. It includes a test harness as well as an environment simulation of external events and conditions

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Characterization of Failure Handling in Fault-Tolerant Multiprocessor Systems.

Traditional reliability-related models for fault-tolerant systems are used to predict system reliability, availability, computation capacity, or performability. They lack the capacity to treat in detail the handling and the consequences of failure. Also, there is insufficient attention paid to the fact that a system crash could follow any mishandling of failure. Failure h and ling consists of three major steps: error detection, system reconfiguration, and computation recovery. These steps must be considered together as a single package, not as separate entities as in the traditional analyses. Such an integration can be extended to develop design aids for fault-tolerant computers. The dissertation begins with the modeling of fault/error detection mechanisms which are designed to identify faulty units. When fault latency and /or error latency exist, the system may suffer from the propagation of errors and the accumulation of extant faults which will seriously reduce the fault-tolerant capability. Several detection models are developed so that we can study the effect of detection mechanisms on the subsequent error h and ling and overall system reliability. Upon detection of a faulty unit, the system should reconfigure itself into an optimal configuration so that the total reward to be achieved from the subsequent executions may be maximized. Finally, the contaminated processes have to be recovered. The strategies of error recovery employed will depend on the detection mechanisms and the redundancy available. Several recovery methods, especially retry and rollback, are analyzed. The recovery overheads are evaluated, providing an index of the capabilities of the detection and reconfiguration mechanisms.Ph.D.Computer scienceUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/160550/1/8512452.pd