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We present a detailed account of a translation from probabilistic call-by-value programs with procedures to Rabin's probabilistic automata. The translation is fully abstract in that programs exhibit the same computational behaviour if and only if the corresponding automata are language-equivalent. Since probabilistic language equivalence is decidable, we can apply the translation to analyse the behaviour of probabilistic programs and protocols. We illustrate our approach on a number of case studies. © 2012 Springer Science+Business Media, LLC.

We present a static deadlock analysis approach for C/pthreads. The design of our method has been guided by the requirement to analyse real-world code. Our approach is sound (i.e., misses no deadlocks) for programs that have defined behaviour according to the C standard, and precise enough to prove deadlock-freedom for a large number of programs. The method consists of a pipeline of several analyses that build on a new context- and thread-sensitive abstract interpretation framework. We further present a lightweight dependency analysis to identify statements relevant to deadlock analysis and thus speed up the overall analysis. In our experimental evaluation, we succeeded to prove deadlock-freedom for 262 programs from the Debian GNU/Linux distribution with in total 2.6 MLOC in less than 11 hours.

Background: The Patient Protection and Affordable Care Act (ACA) galvanised debate in the United States (US) over universal health coverage. Comparison with countries providing universal coverage may illustrate whether the ACA can improve health outcomes and reduce disparities. We aimed to compare quality and disparities in hypertension management by socio-economic position in the US and England, the latter of which has universal health care. Method: We used data from the Health and Retirement Survey in the US, and the English Longitudinal Study for Aging from England, including non-Hispanic White respondents aged 50–64 years (US market-based v NHS) and .65 years (USMedicare v NHS) with diagnosed hypertension. We compared blood pressure control to clinical guideline (140/90 mmHg) and audit (150/90 mmHg) targets; mean systolic and diastolic blood pressure and antihypertensive prescribing, and disparities in each by educational attainment, income and wealth, using regression models. Results: There were no significant differences in aggregate achievement of clinical targets aged 50 to 65 years (US marketbased vs. NHS- 62.3% vs. 61.3% [p = 0.835]). There was, however, greater control in the US in patients aged 65 years and over (US Medicare vs. NHS- 53.5% vs. 58.2% [p = 0.043]). England had no significant socioeconomic disparity in blood pressure control (60.9% vs. 63.5% [p = 0.588], high and low wealth aged $65 years). The US had socioeconomic differences in the 50– 64 years group (71.7% vs. 55.2% [p = 0.003], high and low wealth); these were attenuated but not abolished in Medicare beneficiaries. Conclusion: Moves towards universal health coverage in the US may reduce disparities in hypertension management. The current situation, providing universal coverage for residents aged 65 years and over, may not be sufficient for equality in care.

Network technology enables smarter and more adaptive computing devices in the context of vehicles, communication and energy networks. Performance and quality-of-service guarantees are vital concerns for such systems. Meaningful guarantees are typically of a probabilistic nature due to the use of randomized algorithms inside network protocols and other phenomena like message loss. Probabilistic verification provides methods and tools to quantify the performance and quality of service of systems. A central problem in probabilistic verification is to determine the probability that a system enters a particular set of goal states, e.g., states in which packages have been transmitted successfully. Despite the remarkable versatility of existing methods, they are inherently limited to systems with very small state spaces. This dissertation proposes new methods that solve the problem of probabilistic reach- ability for large or even infinite state spaces. The key is to automatically obtain small abstractions of a system. To this end, we start with a very coarse abstraction and successively refine it. The process is fully automatic and has been implemented in the tool Pass. Pass achieves significant performance improvements compared to previous methods and, further, applies to infinite-state systems which could previously not be handled by any existing automatic method.

The design of complex concurrent systems often involves intricate performance and dependability considerations. Continuous-time Markov chains (CTMCs) are a widely used modeling formalism, where performance and dependability properties are analyzable by model checking. We present INFAMY, a model checker for arbitrarily structured infinite-state CTMCs. It checks probabilistic timing properties expressible in continuous stochastic logic (CSL). Conventional model checkers explore the given model exhaustively, which is often costly, due to state explosion, and impossible if the model is infinite. INFAMY only explores the model up to a finite depth, with the depth bound being computed on-the-fly. The computation of depth bounds is configurable to adapt to the characteristics of different classes of models.

The objective of this study is to quantify an estimate of ship’s aerial emissions in the Belgian part of the North Sea, including the 4 most important Belgian ports: Antwerp, Ghent, Ostend and Zeebrugge and this for the period from April 2003 to March 2004. This quantification gives an overview of ship’s aerial emission of CO2, SO2 and NOx and can be used as an input to the discussions on regulating shipping emissions in the framework of combating air pollution and climate change. First an overview is given of existing and upcoming international standards and reporting requirements; followed by the current emission inventories in use in Belgium. Next, a new method is used to estimate the emissions of shipping. The method classifies ships into 15 classes and 2 different calculation methods, depending on the best available data: for 11 types of merchant ships, dredgers and tugs in non-operational condition and fishery (emissions by the Belgian fishing fleet in the Belgian part of the North Sea) a bottom-up approach is applied, for dredgers and tugs in operational condition a top-down approach is used. For LNG vessels we have to take the specific engine characteristics into account. Further, we also make a distinction between at sea and in port emissions, because of different sailing operations (whether cruising, at berth, manoeuvring or at anchor). In the bottom-up approach, the engine loads are the most significant information and can be used to estimate the subsequent emissions, together with information on sailing times and emission factors. The top-down approach allows for a more simple calculation on the basis of fuel consumption and related emission factors. When adding the total at sea and in port emission estimates from both the bottom-up and top-down approach we have the total estimate of ship’s aerial emission in the Belgian part of the North Sea and the 4 most important ports. Unfortunately, a lack of data (due to a limited coverage of ship registration at the time) has not allowed to incorporate emissions from transit ships, passing the Belgian North Sea in the North bound Traffic Separation Scheme.

RAMA is a 2-year project (04/2004 - 04/2006) executed by two Belgian partners, Ecolas NV (Environmental Consultancy Agency) and the Maritime Institute (University of Ghent), and financed by the SPSD II research program, specific actions, of the Belgian Science Policy (BELPSO). RAMA aims to assess the environmental risks of spills by commercial shipping activities on the Belgian Part of the North Sea. Shipping patterns, transports of dangerous goods, probability of risks and the potential impact of spill incidents (oil & hazardous and noxious substances) will be assessed. The risk analysis within this project studies both the chances of a spill accident happening and the environmental impacts in case of an accident. The valorisation of the RAMA project will result in a thorough analysis of the current status of the shipping at the North Sea in relation to the issue of safety. The scope of the project will however go beyond the mere result of a fundamental risk analysis of the commercial shipping at the North Sea. It is also aiming at the formulation of recommendations to improve the safety level for the environment and at an optimization of response in the framework of the Belgian "North Sea Disaster Plan".