Run-Time Verification of Black-Box Components Using Behavioral Specifications: An Experience Report on Tool Development

htmlabstractWe introduce a generic component-based design of a run-time checker, identify its components and their requirements, and evaluate existing state of the art tools instantiating each component

The known unknowns of hydraulic engineering

Hydraulic engineers and researchers deal with scientific challenges involving turbulent flow motion and its interactions with the surroundings. Turbulent flows are characterised by unpredictable behaviour, and little systematic research has yet been conducted in natural systems. This paper discusses the implications of recent developments in affordable instrumentation previously characterised by intrinsic weaknesses that adversely affect the quality of the signal outputs. A challenging application is the unsteady turbulence field in tidal bores. The interactions between open channel flows and movable boundaries and atmosphere illustrate another aspect of our limited knowledge. Rapid siltation of reservoirs and air entrainment in turbulent free-surface flows are discussed. In both applications, hydraulic engineers require some broad-based expertise. In turn the education of future hydraulic engineers is of vital importance

Run-Time Assertion Checking of Data- and Protocol-Oriented Properties of Java Programs: An Industrial Case Study

htmlabstractRun-time assertion checking is one of the useful techniques for detecting faults, and can be applied during any program execution context, including debugging, testing, and production. In general, however, it is limited to checking state-based properties. We introduce SAGA, a general framework that provides a smooth integration of the specification and the run-time checking of both data- and protocol-oriented properties of Java classes and interfaces. We evaluate SAGA, which combines several state-of-the art tools, by conducting an industrial case study from an eCommerce software company Fredhopper

Evaluation of clinical, laboratory and morphologic prognostic factors in colon cancer

<p>Abstract</p> <p>Background</p> <p>The long-term prognosis of patients with colon cancer is dependent on many factors. To investigate the influence of a series of clinical, laboratory and morphological variables on prognosis of colon carcinoma we conducted a retrospective analysis of our data.</p> <p>Methods</p> <p>Ninety-two patients with colon cancer, who underwent surgical resection between January 1999 and December 2001, were analyzed. On survival analysis, demographics, clinical, laboratory and pathomorphological parameters were tested for their potential prognostic value. Furthermore, univariate and multivariate analysis of the above mentioned data were performed considering the depth of tumour invasion into the bowel wall as independent variable.</p> <p>Results</p> <p>On survival analysis we found that depth of tumour invasion (P < 0.001; F-ratio 2.11), type of operation (P < 0.001; F-ratio 3.51) and CT scanning (P < 0.001; F-ratio 5.21) were predictors of survival. Considering the degree of mural invasion as independent variable, on univariate analysis, we observed that mucorrhea, anismus, hematocrit, WBC count, fibrinogen value and CT scanning were significantly related to the degree of mural invasion of the cancer. On the multivariate analysis, fibrinogen value was the most statistically significant variable (P < 0.001) with the highest F-ratio (F-ratio 5.86). Finally, in the present study, the tumour site was significantly related neither to the survival nor to the mural invasion of the tumour.</p> <p>Conclusion</p> <p>The various clinical, laboratory and patho-morphological parameters showed different prognostic value for colon carcinoma. In the future, preoperative prognostic markers will probably gain relevance in order to make a proper choice between surgery, chemotherapy and radiotherapy. Nevertheless, current data do not provide sufficient evidence for preoperative stratification of high and low risk patients. Further assessments in prospective large studies are warranted.</p

Formal Verification By Reverse Synthesis

Abstract. In this paper we describe Echo, a novel yet practical approach to the formal verification of implementations. Echo splits verification into two major parts. The first part verifies an implementation against a low-level specification. The second uses a technique called reverse synthesis to extract a high-level specification from the low-level specification. The extracted specification is proved to imply the original system specification. Much of Echo is automated, and it reduces the verification burden by distributing it over separate tools and techniques. Reverse synthesis is achieved largely by mechanically applying a variety of semantics-preserving transformations, including complexity-reducing transformations, which can be viewed as optimizing the program for verification rather than for size or speed. We give a detailed example of Echo, verifying an implementation of the Advanced Encryption Standard (AES) against the official specification of AES