On the complexity of semantic self-minimization

Partial Kripke structures model only parts of a state space and so enable aggressive abstraction of systems prior to verifying them with respect to a formula of temporal logic. This partiality of models means that verifications may reply with true (all refinements satisfy the formula under check), false (no refinement satisfies the formula under check) or dont know. Generalized model checking is the most precise verification for such models (all dont know answers imply that some refinements satisfy the formula, some dont), but computationally expensive. A compositional model-checking algorithm for partial Kripke structures is efficient, sound (all answers true and false are truthful), but may lose precision by answering dont know instead of a factual true or false. Recent work has shown that such a loss of precision does not occur for this compositional algorithm for most practically relevant patterns of temporal logic formulas. Formulas that never lose precision in this manner are called semantically self-minimizing. In this paper we provide a systematic study of the complexity of deciding whether a formula of propositional logic, propositional modal logic or the propositional modal mu-calculus is semantically self-minimizing. © 2009 Elsevier B.V. All rights reserved

Efficient Patterns for Model Checking Partial State Spaces in CTL & LTL

Compositional model checks of partial Kripke structures are efficient but incomplete as they may fail to recognize that all implementations satisfy the checked property. But if a property holds for such checks, it will hold in all implementations. Such checks are therefore under-approximations. In this paper we determine for which popular specification patterns, documented at a communityled pattern repository, this under-approximation is precise in that the converse relationship holds as well for all model checks. We find that many such patterns are indeed precise. Those that arent lose precision because of a sole propositional atom in mixed polarity. Hence we can compute, with linear blowup only, a semantic minimization in the same temporal logic whose efficient check renders the precise result for the original imprecise pattern. Thus precision can be secured for all patterns at low cost. © 2006 Elsevier B.V. All rights reserved

Volunterin as a form of civic position of youth

In this article authors consider volunteering as a form of manifestation of an active youth citizenship. Besides, the article reviews the history of emergence of concepts "volunteering" and "volunteerism", analyzes international and Russian legal frameworks for supporting volunteering. Also the authors consider volunteering as the most important resource for the development of the Russian society and significant part of Russia's youth policy.В статье авторы рассматривают волонтерство как форму проявления гражданской активности молодежи. Кроме того, в статье приведена история возникновения понятий «волонтерство» и «добровольчество», проанализированы международные и российские нормативные правовые акты, касающиеся поддержки добровольческой деятельности. Также авторы рассматривают добровольчество как важнейший ресурс развития российского общества и важную часть молодежной политики России

Silicon resonant microcantilevers for absolute pressure measurement

This work is focused on the developing of silicon resonant microcantilevers for the measurement of the absolute pressure. The microcantilevers have been fabricated with a two-mask bulk micromachining process. The variation in resonance response of microcantilevers was investigated as a function of pressure 10−1-105 Pa, both in terms of resonance frequency and quality factor. A theoretical description of the resonating microstructure is given according to different molecular and viscous regimes. Also a brief discussion on the different quality factors contributions is presented. Theoretical and experimental data show a very satisfying agreement. The microstructure behavior demonstrates a certain sensitivity over a six decade range and the potential evolution of an absolute pressure sensor working in the same rang

On Refinements of Boolean and Parametric Modal Transition Systems

We consider the extensions of modal transition systems (MTS), namely Boolean MTS and parametric MTS and we investigate the refinement problems over both classes. Firstly, we reduce the problem of modal refinement over both classes to a problem solvable by a QBF solver and provide experimental results showing our technique scales well. Secondly, we extend the algorithm for thorough refinement of MTS providing better complexity then via reductions to previously studied problems. Finally, we investigate the relationship between modal and thorough refinement on the two classes and show how the thorough refinement can be approximated by the modal refinement

Genome-wide sequence analyses of ethnic populations across Russia

The Russian Federation is the largest and one of the most ethnically diverse countries in the world, however no centralized reference database of genetic variation exists to date. Such data are crucial for medical genetics and essential for studying population history. The Genome Russia Project aims at filling this gap by performing whole genome sequencing and analysis of peoples of the Russian Federation. Here we report the characterization of genome-wide variation of 264 healthy adults, including 60 newly sequenced samples. People of Russia carry known and novel genetic variants of adaptive, clinical and functional consequence that in many cases show allele frequency divergence from neighboring populations. Population genetics analyses revealed six phylogeographic partitions among indigenous ethnicities corresponding to their geographic locales. This study presents a characterization of population-specific genomic variation in Russia with results important for medical genetics and for understanding the dynamic population history of the world's largest country

Quantitative Modal Transition Systems

International audienceThis extended abstract offers a brief survey presentation of the specification formalism of modal transition systems and its recent extensions to the quantitative setting of timed as well as stochastic systems. Some applications will also be briefly mentioned