Towards the specification and verification of modal properties for structured systems

System specification formalisms should come with suitable property specification languages and effective verification tools. We sketch a framework for the verification of quantified temporal properties of systems with dynamically evolving structure. We consider visual specification formalisms like graph transformation systems (GTS) where program states are modelled as graphs, and the program behavior is specified by graph transformation rules. The state space of a GTS can be represented as a graph transition system (GTrS), i.e. a transition system with states and transitions labelled, respectively, with a graph, and with a partial morphism representing the evolution of state components. Unfortunately, GTrSs are prohibitively large or infinite even for simple systems, making verification intractable and hence calling for appropriate abstraction techniques

A Logic for True Concurrency

We propose a logic for true concurrency whose formulae predicate about events in computations and their causal dependencies. The induced logical equivalence is hereditary history preserving bisimilarity, and fragments of the logic can be identified which correspond to other true concurrent behavioural equivalences in the literature: step, pomset and history preserving bisimilarity. Standard Hennessy-Milner logic, and thus (interleaving) bisimilarity, is also recovered as a fragment. We also propose an extension of the logic with fixpoint operators, thus allowing to describe causal and concurrency properties of infinite computations. We believe that this work contributes to a rational presentation of the true concurrent spectrum and to a deeper understanding of the relations between the involved behavioural equivalences.Comment: 31 pages, a preliminary version appeared in CONCUR 201

Flexicurity in EU Countries

Flexicurity is a new way of looking at flexibility and security on the labor market. It sets out from the awareness that globalization and technological progress are rapidly changing the needs of workers and enterprises. Companies are under increasing pressure to adapt and develop their products and services more quickly. If they want to stay in the market, they have to continuously adapt their production methods and their workforce. This is placing greater demands on business to help their workers acquire new skills. It is also placing greater demands on workers with regards to their ability and readiness for change. At the same time, workers are aware that company restructurings no longer occur incidentally, but are becoming a fact of everyday life. Protection of the specific job they have may no longer be sufficient, and might indeed be counterproductive. In order to plan their lives and careers, workers need new kinds of security that help them remain in employment, and make it through all these changes. New securities must go beyond the specific job and ensure safe transitions into new employment. Flexicurity is an attempt to unite these two fundamental needs. Flexicurity promotes a combination of flexible labor markets and a high level of employment and income security and it is thus seen to be the answer to the EU's dilemma of how to maintain and improve competitiveness whilst preserving the European social model. Flexicurity can be defined, more precisely, as a policy strategy to enhance, at the same time and in a deliberate way, the flexibility of labor markets, work organizations and labor relations on the one hand, and security –employment security and income security – on the other.flexicurity; flexibility; security; benefits; labour force

The Employment and Unemployment in Romania - Decisive Factors

The employment, but also the efficient use of the available work resources is directly connected to the work market. It is an element that cannot be separated from the other elements of the work market, especially from unemployment, because if one deals with them separately, one cannot cover all the aspects, particularities and effects on the work factor. There are many causes for unemployment, causes that are to be found both at the macroeconomic level and at the microeconomic level. In most of the cases, in an analysis that aims at finding the causes that have generated the unemployment, many characteristics of unemployment are taken into account and they are analysed as “types” of unemployment.Employment; Unemployment; Wages; Intergenerational Income Distribution;

The structure and strength of certain Ni-Al-Ta and Ni-Al-Hf alloys

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The Employment and Unemployment in Romania - Decisive Factors

The employment, but also the efficient use of the available work resources is directly connected to the work market. It is an element that can not be separated from the other elements of the work market, especially from unemployment, because if one deals with them separately, one can not cover all the aspects, particularities and effects on the work factor. There are many causes for unemployment, causes that are to be found both at the macroeconomic level and at the microeconomic level. In most of the cases, in an analysis that aims at finding the causes that have generated the unemployment, many characteristics of unemployment are taken into account and they are analysed as “types” of unemployment.Employment; Unemployment; Wages; Intergenerational Income Distribution

Beneficial Bacteria Isolated from Grapevine Inner Tissues Shape Arabidopsis thaliana Roots

We investigated the potential plant growth-promoting traits of 377 culturable endophytic bacteria, isolated from Vitis vinifera cv. Glera, as good biofertilizer candidates in vineyard management. Endophyte ability in promoting plant growth was assessed in vitro by testing ammonia production, phosphate solubilization, indole-3-acetic acid (IAA) and IAA-like molecule biosynthesis, siderophore and lytic enzyme secretion. Many of the isolates were able to mobilize phosphate (33%), release ammonium (39%), secrete siderophores (38%) and a limited part of them synthetized IAA and IAA-like molecules (5%). Effects of each of the 377 grapevine beneficial bacteria on Arabidopsis thaliana root development were also analyzed to discern plant growth-promoting abilities (PGP) of the different strains, that often exhibit more than one PGP trait. A supervised model-based clustering analysis highlighted six different classes of PGP effects on root architecture. A. thaliana DR5::GUS plantlets, inoculated with IAA-producing endophytes, resulted in altered root growth and enhanced auxin response. Overall, the results indicate that the Glera PGP endospheric culturable microbiome could contribute, by structural root changes, to obtain water and nutrients increasing plant adaptation and survival. From the complete cultivable collection, twelve promising endophytes mainly belonging to the Bacillus but also to Micrococcus and Pantoea genera, were selected for further investigations in the grapevine host plants towards future application in sustainable management of vineyards

Solving 1D non-linear magneto quasi-static Maxwell's equations using neural networks

Electromagnetics (EM) can be described, together with the constitutive laws, by four PDEs, called Maxwell's equations. “Quasi-static” approximations emerge from neglecting particular couplings of electric and magnetic field related quantities. In case of slowly time varying fields, if inductive and resistive effects have to be considered, whereas capacitive effects can be neglected, the magneto quasi-static (MQS) approximation applies. The solution of the MQS Maxwell's equations, traditionally obtained with finite differences and elements methods, is crucial in modelling EM devices. In this paper, the applicability of an unsupervised deep learning model is studied in order to solve MQS Maxwell's equations, in both frequency and time domain. In this framework, a straightforward way to model hysteretic and anhysteretic non-linearity is shown. The introduced technique is used for the field analysis in the place of the classical finite elements in two applications: on the one hand, the B–H curve inverse determination of AISI 4140, on the other, the simulation of an induction heating process. Finally, since many of the commercial FEM packages do not allow modelling hysteresis, it is shown how the present approach could be further adopted for the inverse magnetic properties identification of new magnetic flux concentrators for induction applications

Coalgebraic Behavioral Metrics

We study different behavioral metrics, such as those arising from both branching and linear-time semantics, in a coalgebraic setting. Given a coalgebra $\alpha\colon X \to HX$ for a functor $H \colon \mathrm{Set}\to \mathrm{Set}$, we define a framework for deriving pseudometrics on $X$ which measure the behavioral distance of states. A crucial step is the lifting of the functor $H$ on $\mathrm{Set}$ to a functor $\overline{H}$ on the category $\mathrm{PMet}$ of pseudometric spaces. We present two different approaches which can be viewed as generalizations of the Kantorovich and Wasserstein pseudometrics for probability measures. We show that the pseudometrics provided by the two approaches coincide on several natural examples, but in general they differ. If $H$ has a final coalgebra, every lifting $\overline{H}$ yields in a canonical way a behavioral distance which is usually branching-time, i.e., it generalizes bisimilarity. In order to model linear-time metrics (generalizing trace equivalences), we show sufficient conditions for lifting distributive laws and monads. These results enable us to employ the generalized powerset construction