Property-preserving synthesis for unified conrol- and data-oriented models.

In the software/hardware engineering model-driven design methodology, preservation of real-time system properties can be guaranteed in the model synthesis up to a small time-deviation. Therefore, this methodology is well suited for the design and implementation of control systems in which execution times of actions are small; thus the time-deviations obtained are small. However, in systems containing time-intensive computations, the time-deviations become large and, consequently, the real-time properties are much weakened. This chapter proposes an approach for obtaining stronger preservation of the observable properties of the system by abstracting from its internal unobservable actions. In this way, a unified way of analysis and synthesis of a larger area of real-time applications can be obtained, which enables designers to achieve predictability in the design of many systems

Discrete-time rewards model-checked

This paper presents a model-checking approach for analyzing discrete-time Markov reward models. For this purpose, the temporal logic probabilistic CTL is extended with reward constraints. This allows to formulate complex measures – involving expected as well as accumulated rewards – in a precise and succinct way. Algorithms to efficiently analyze such formulae are introduced. The approach is illustrated by model-checking a probabilistic cost model of the IPv4 zeroconf protocol for distributed address assignment in ad-hoc networks

Onzekerheid over de baten van de Betuwelijn

Model estimates of the pay-off of the Betuwe railway have played an important role for politicians to decide to build this railway. This has already been discussed extensively, especially with respect to the macro-economic effects of this investment. A deeper analysis shows that these effects are very difficult to assess. The NIJFER institute for example calculated a long term profit of 52.1 biljon Dutch guilders, but our analysis of this model shows that the profit lays with 50 reliability between 15 and 30 biljon Dutch guilders. Our conclusion is that this political investment decision is not sufficiently supported by the expected macro-economic pay-off. A prudent use of quantitative research requires that the involved uncertainties in the model outcomes is properly taken into account

Onzekerheid over de baten van de Betuwelijn

Model estimates of the pay-off of the Betuwe railway have played an important role for politicians to decide to build this railway. This has already been discussed extensively, especially with respect to the macro-economic effects of this investment. A deeper analysis shows that these effects are very difficult to assess. The NIJFER institute for example calculated a long term profit of 52.1 biljon Dutch guilders, but our analysis of this model shows that the profitlays with 50 reliability between 15 and 30 biljon Dutch guilders. Our conclusion is that this political investment decision is not sufficiently supported by the expected macro-economic pay-off. A prudent use of quantitative research requires that the involved uncertainties in the model outcomes is properly taken into account.investment;cross-country analysis;regression;infrastructure;policy design

Determinants of intention to get tested for STI/HIV among the Surinamese and Antilleans in the Netherlands: Results of an online survey

Background: High infection rates of STIs are found among the different ethnic communities living in the Netherlands, especially among the Surinamese and Dutch-Antilleans. Only limited effective interventions that promote STI/HIV testing among these communities are available in the Netherlands. In the present study we identified the determinants of the intention to get tested for STI/HIV of the sexually active Surinamese and Dutch-Antilleans living in the Netherlands. Secondly, this study assesses which determinants should be addressed when promoting STI/HIV testing among these communities. Methods. In total, 450 Surinamese and 303 Dutch-Antillean respondents were recruited through Dutch Internet panels and group activities. The questionnaire used in the online survey was based on the concepts of the Health Belief Model, the Social Cognitive Theory, and Theory of Planned behavior. To correct for multiple outcome testing, we considered differences as statistically significant at p<.01 for all analyses. For the multivariate linear regression analysis, variables that were significant were entered into the model block-wise. Results: Health motivation, cues to action, subjective norms, risk behavior, test history, open communication about sexuality, and marital status were important (univariate) predictors of the intention to get tested for STI/HIV for both the Surinamese and Dutch-Antillean respondents. For both the Surinamese and Dutch-Antilleans, subjective norms were the most salient predictor of the intention to get tested in multivariate analyses, explaining 10% and 13% of the variance respectively; subjective norms had a direct influence on the intention for both the Surinamese and the Dutch-Antilleans. Conclusions: The strong correlation and predictive power of subjective norms on the intention to get tested for STI/HIV, endorses the importance of focusing on community-based intervention rather than focusing on personal determinants, to change the present perceptions and attitudes towards testing. Health promoting programs should be aimed at promoting open communication regarding sexuality and testing. Stimulating each other to get tested frequently could also help achieving the desired behavior

The behaviour of political parties and MPs in the parliaments of the Weimar Republic

Copyright @ 2012 The Authors. This is the author's accepted manuscript. The final published article is available from the link below.Analysing the roll-call votes of the MPs of the Weimar Republic we find: (1) that party competition in the Weimar parliaments can be structured along two dimensions: an economic left–right and a pro-/anti-democratic. Remarkably, this is stable throughout the entire lifespan of the Republic and not just in the later years and despite the varying content of votes across the lifespan of the Republic, and (2) that nearly all parties were troubled by intra-party divisions, though, in particular, the national socialists and communists became homogeneous in the final years of the Republic.Zukunftskolleg, University of Konstan