63 research outputs found
A foundation for runtime monitoring
Runtime Verification is a lightweight technique that complements other verification methods in an effort to ensure software correctness. The technique poses novel questions to software engineers: it is not easy to identify which specifications are amenable to runtime monitor-ing, nor is it clear which monitors effect the required runtime analysis correctly. This exposition targets a foundational understanding of these questions. Particularly, it considers an expressive specification logic (a syntactic variant of the modal ÎĽ-calculus) that is agnostic of the verification method used, together with an elemental framework providing an operational semantics for the runtime analysis performed by monitors. The correspondence between the property satisfactions in the logic on the one hand, and the verdicts reached by the monitors performing the analysis on the other, is a central theme of the study. Such a correspondence underpins the concept of monitorability, used to identify the subsets of the logic that can be adequately monitored for by RV. Another theme of the study is that of understanding what should be expected of a monitor in order for the verification process to be correct. We show how the monitor framework considered can constitute a basis whereby various notions of monitor correctness may be defined and investigated.peer-reviewe
A Foundation for Runtime Monitoring
Runtime Verification is a lightweight technique that complements other
verification methods in an effort to ensure software correctness.
The technique poses novel questions to software engineers: it is not easy to
identify which specifications are amenable to runtime monitoring, nor is it
clear which monitors effect the required runtime analysis correctly.
This exposition targets a foundational understanding of these questions.
Particularly, it considers an expressive specification logic (a syntactic
variant of the mmucalc) that is agnostic of the verification method used,
together with an elemental framework providing an operational semantics for the
runtime analysis performed by monitors.
The correspondence between the property satisfactions in the logic on the one
hand, and the verdicts reached by the monitors performing the analysis on the
other, is a central theme of the study.
Such a correspondence underpins the concept of monitorability, used to identify
the subsets of the logic that can be adequately monitored for by RV.
Another theme of the study is that of understanding what should be expected of a
monitor in order for the verification process to be correct.
We show how the monitor framework considered can constitute a basis whereby
various notions of monitor correctness may be defined and investigated
Isolated Extra-Corporeal Coronary Perfusion Circuit for Use During Off-Pump Coronary Artery Bypass Grafting
Cardiovascular surgery would not have developed into its present form without the heart–lung machine. In coronary artery bypass grafting (CABG), cardiopulmonary bypass allows accurate, all site, complete revascularization in a way convenient to the surgeon. The aim of this circuit is to find new ways to reduce invasiveness of CABG and to create new basis conditions for successful coronary bypass grafting on the beating heart. Manipulation of the heart compromises collateral coronary flow, especially to critically narrowed coronaries. This circuit standardizes our method for perfusing blood through the coronary bypass grafts with controlled positive pressure as each distal anastomosis is made, and it preserves collateral coronary flow, while facilitating construction of the remaining distal anastomoses
Early versus delayed endocrine treatment of pN1-3 M0 prostate cancer without local treatment of the primary tumor: results of European Organisation for the Research and Treatment of Cancer 30846--a phase III study
The timing of endocrine treatment for prostate cancer remains controversial. The issue is addressed in protocol 30846 of the European Organisation for Research and Treatment of Cancer for patients with lymph node positive cancer without local treatment of the primary tumor. A total of 302 patients with metastatic regional lymph nodes who had not received local treatment for the primary tumor were included in the trial, of whom 234 were randomized to immediate vs delayed endocrine treatment. Endocrine treatment consisted of an luteinizing hormone-releasing hormone agonist and 1 month of antiandrogen treatment or surgical castration. The main end point of the trial was overall survival. Analysis followed the intent to treat principle. At a median followup of 9.6 years (8.7 in the randomized sample) 190 patients (62.9%) had died, including 76% of prostate cancer. In the randomized sample the HR for survival on delayed vs immediate treatment was 1.23 (95% CI 0.88 to 1.71), indicating a 23% nonsignificant trend in favor of early treatment. However, the wide CI showed that results remained compatible with true effects, ranging from a 12% benefit in favor of delayed treatment to a 71% detriment for the same treatment approach. While this study suggests an advantage for early treatment, it is under powered to show equivalence or superiority for the early or delayed approach. When dealing with individual patients, the potential survival advantage on early treatment must be balanced against potential advantages in quality of life on delayed treatmen
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