Protocol-Safe Workflow Support for Santa Claus

Practical software analysis techniques exploit a form a process description, mostly in some \ud avour of state diagram. Unlike typing information, these process structures are usually not passed down to the implementation level, and neither are they exploited in any form of consistency check. It is our belief that the information in most designs suffices to perform all sorts of consistency checks. This workshop paper studies a simple case where work\ud ow processes interact with `actual' objects at the implementation level, and demonstrates how useful protocol checking can be in making and keeping these processes consistent with each other

On Practical Verification of Processes

The integration of a formal process theory with a practically usable notation is not straightforward, but it is necessary for practical verification of process specifications. Given such an intermediate language, a verification process that gives useful feedback is not trivial either: Model checkers are not powerful enough to deal with object models, and theorem provers provide insu#cient feedback and are not certain to find a proof

Home-grown CASE tools with XML and XSLT

This paper demonstrates an approach to software generation where xml representations of models are transformed to implementations by XSLT style sheets. Although XSLT was not primarily intended for this use, it serves quite well. There are only few problems in this approach, and we identify these based on our examples

Risk-based supervision of pension institutions in Denmark

This paper examines the move towards risk-based supervision of pension institutions in Denmark. Although Denmark has not adopted a comprehensive model to assess risk it has developed a number of building blocks which it uses for risk-based assessment. The motivations for improving risk assessment include a desire to identify emerging problems, and concerns about the solvency of pension institutions. In Denmark there is extensive use of guaranteed minimum returns in both the accumulation and payout phases which create substantial obligations on pension institutions, and focus attention on the integrity and solvency of the institutions which provide them. In conjunction with freeing up investment restrictions and moving towards market valuation of assets, the supervisor has introduced a'traffic light'stress test model which calculates the effect of several market scenarios - the red test which is the more plausible and the yellow test which is possible but less likely. In addition to the use of the traffic light system, there has been a growing emphasis on the adequacy of internal risk control systems and greater reliance on market discipline. Pension institutions have sought to reduce their exposure to market volatility by better matching of assets and liabilities. There is a much better understanding of the risks inherent in the pension institutions'portfolios, and there has been a substantial increase in the use of hedging instruments.Debt Markets,,Emerging Markets,Insurance&Risk Mitigation,Banks&Banking Reform

Enzyme localization can drastically affect signal amplification in signal transduction pathways

Push-pull networks are ubiquitous in signal transduction pathways in both prokaryotic and eukaryotic cells. They allow cells to strongly amplify signals via the mechanism of zero-order ultrasensitivity. In a push-pull network, two antagonistic enzymes control the activity of a protein by covalent modification. These enzymes are often uniformly distributed in the cytoplasm. They can, however, also be colocalized in space, for instance, near the pole of the cell. Moreover, it is increasingly recognized that these enzymes can also be spatially separated, leading to gradients of the active form of the messenger protein. Here, we investigate the consequences of the spatial distributions of the enzymes for the amplification properties of push-pull networks. Our calculations reveal that enzyme localization by itself can have a dramatic effect on the gain. The gain is maximized when the two enzymes are either uniformly distributed or colocalized in one region in the cell. Depending on the diffusion constants, however, the sharpness of the response can be strongly reduced when the enzymes are spatially separated. We discuss how our predictions could be tested experimentally.Comment: PLoS Comp Biol, in press. 32 pages including 6 figures and supporting informatio

Extending Model Checking to Object Process Validation

Object-oriented techniques allow the gathering and modelling\ud of system requirements in terms of an application area. The\ud expression of data and process models at that level is a great\ud asset in communication with non-technical people in that area,\ud but it does not necessarily lead to consistent models. To avoid\ud that inconsistencies are only discovered during the latest phases\ud of development, it is helpful if analysis models can be verified,\ud especially if this is done in an automated process and if it gives\ud feedback that helps repair the models. This thesis presents\ud such an approach for the process aspects of analysis models