6,353 research outputs found
Synthesizing Robust Systems with RATSY
Specifications for reactive systems often consist of environment assumptions
and system guarantees. An implementation should not only be correct, but also
robust in the sense that it behaves reasonably even when the assumptions are
(temporarily) violated. We present an extension of the requirements analysis
and synthesis tool RATSY that is able to synthesize robust systems from GR(1)
specifications, i.e., system in which a finite number of safety assumption
violations is guaranteed to induce only a finite number of safety guarantee
violations. We show how the specification can be turned into a two-pair Streett
game, and how a winning strategy corresponding to a correct and robust
implementation can be computed. Finally, we provide some experimental results.Comment: In Proceedings SYNT 2012, arXiv:1207.055
Parameterized Synthesis
We study the synthesis problem for distributed architectures with a
parametric number of finite-state components. Parameterized specifications
arise naturally in a synthesis setting, but thus far it was unclear how to
detect realizability and how to perform synthesis in a parameterized setting.
Using a classical result from verification, we show that for a class of
specifications in indexed LTL\X, parameterized synthesis in token ring networks
is equivalent to distributed synthesis in a network consisting of a few copies
of a single process. Adapting a well-known result from distributed synthesis,
we show that the latter problem is undecidable. We describe a semi-decision
procedure for the parameterized synthesis problem in token rings, based on
bounded synthesis. We extend the approach to parameterized synthesis in
token-passing networks with arbitrary topologies, and show applicability on a
simple case study. Finally, we sketch a general framework for parameterized
synthesis based on cutoffs and other parameterized verification techniques.Comment: Extended version of TACAS 2012 paper, 29 page
Evaluation of PV technology implementation in the building sector
This paper presents a simulation case that shows the impact on energy consumption of a building applying photovoltaic shading systems. In order to make photovoltaic application more economical, the effect of a photovoltaic facade as a passive cooling system can result in a considerable energy cost reduction, with positive influence on the payback time of the photovoltaic installation. Photovoltaic shading systems can be applied to both refurbishment of old buildings and to new-build, offering attractive and environmentally integrated architectural solutions
Smallpox and Bioterrorism: Why the Plan to Protect the Nation Is Stalled and What to Do
The Iraq war is over, no weapons of mass destruction (WMD) have yet been found, and the president's smallpox plan, though sound, is running out of steam. Instead of being well on the way to protecting the nation's civilian population by vaccinating up to 10 million health, emergency, and public safety workers, we are stalled at 37,971 vaccinated civilians while the military has successfully and safely vaccinated more than 450,000 people. Moreover, whether or not WMD are found in Iraq, it is only one of a number of nations on the list of suspects. Of all biological weapons, smallpox has the greatest potential for doing widespread harm. Given that the risk of death or serious harm to anyone from any form of terrorism is very low, we should live our daily lives normally, not in fear. However, to do that we need to be sure that our government is taking effective steps to reduce the chances of terrorism and, when it occurs, to minimize its consequences. Even though there is enough vaccine for everyone, we are ill prepared to rapidly contain smallpox after a bioterrorist release. Although Centers for Disease Control and Prevention (CDC) guidelines have recently improved, they continue to overstate the risk of side effects of the vaccine and erroneously suggest that, after an attack, the techniques used decades ago to eradicate smallpox will work well today. Medicine and public health are very risk-averse professions in our risk-averse culture. We have not yet realized the complexity and difficulty of vaccinating millions of Americans rapidly after an attack. Nor have we come to grips with the need to make rapid, possibly draconian, post-attack decisions based on limited data of uncertain quality. That type of decisionmaking runs counter to the culture of public health. The Bush administration needs to revitalize our preparations for a smallpox bioterrorist event
Disease control by sulphur induced resistance
As early as the 19th century, Justus von Liebig (1803 – 1873) identified the lack of vitality of soils and non-existent vigour of plants as relevant causes of increased infections of crops by fungal diseases. Organic farming requires alternative strategies for combating pests and diseases. Soil-applied sulphate fertilisation proved to significantly reduce infection rate and severity of crops by fungal diseases. The potential efficacy of socalled Sulphur Induced Resistance (SIR) expressed as a reduction of the disease index ranged from 5–50% and 17–35% in greenhouse and field experiments, respectively. Metabolic pathways involved in SIR imply, for instance, the synthesis of phytoalexins, glutathione, glucosinolates and the release of sulphur-containing volatiles
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