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A novel approach to the remote-control system for the compact multi-crystal energy-dispersive spectrometer for X-ray emission spectroscopy (XES) applications has been developed. This new approach is based on asynchronous communication between software components and on reactive design principles. In this paper, the challenges faced, their solutions, as well as the implementation and future development prospects are identified. The main motivation of this work was the development of a new holistic communication protocol that can be implemented to control various hardware components allowing both independent operation and easy integration into different SCADA systems.

A novel approach to the remote-control system for the compact multi-crystal energy-dispersive spectrometer for X-ray emission spectroscopy (XES) applications has been developed. This new approach is based on asynchronous communication between software components and on reactive design principles. In this paper, the challenges faced, their solutions, as well as the implementation and future development prospects are identified. The main motivation of this work was the development of a new holistic communication protocol that can be implemented to control various hardware components allowing both independent operation and easy integration into different SCADA systems. [ABSTRACT FROM AUTHOR]

Reactive synthesis is a technique for automatic generation of a reactive system from a high level specification. The system is reactive in the sense that it reacts to the inputs from the environment. The specification is in general given as a linear temporal logic (LTL) formula. The behaviour of the system interacting with the environment can be represented as a game in which the system plays against the environment. Thus, a problem of reactive synthesis is commonly treated as solving such a game with the specification as the winning condition. Reactive synthesis has been thoroughly investigated for more two decades. A well-known challenge is to deal with the complex uncertainty of the environment. We understand that a major issue is due to the lack of a sufficient treatment of probabilistic properties in the traditional models. For example, a two-player game defined by a standard Kriple structure does not consider probabilistic transitions in reaction to the uncertain physical environment; and a Markov Decision Process (MDP) in general does not explicitly separate the system from its environment and it does not describe the interaction between system and the environment. In this paper, we propose a new and more general model which combines the two-player game and the MDP. Furthermore, we study probabilistic reactive synthesis for the games of General Reactivity of Rank 1 (i.e., GR(1)) defined in this model. More specifically, we present an algorithm, which for given model M, a location s and a GR(1) specification P, determines the strategy for each player how to maximize/minimize the probabilities of the satisfaction of P at location s. We use an example to describe the model of probabilistic games and demonstrate our algorithm. [ABSTRACT FROM AUTHOR]

The present study investigates the wetting behavior of Cr–Mn–Ni-alloys with TRIP/TWIP-effects on the hBN-SiC-ZrO 2 -substrate using the sessile drop method. The wetting behavior was studied in a 90 vol% N 2 /10 vol% H 2 atmosphere in the temperature range of 1500 °C–1600 °C. Experiments were conducted in the reactive steel/ceramic system. Results demonstrate the effect of the nickel and the sulfur content on the contact angle between hBN-SiC-ZrO 2 -substrates and Cr–Mn–Ni-alloys. The increase in the nickel content from 3 to 9 mass% caused the increase of the contact angle from 129 to 138° at 1600 °C. Whereas, the increase in the sulfur content caused the decrease of the contact angle. The contact angle of the melts alloyed with the sulfur increases as the temperature rises. The increase in the contact angle was related to the evaporation of the manganese. In addition, the study discusses the chemical reaction between the hBN-SiC-ZrO 2 -substrate and Cr–Mn–Ni-alloys through (i) SEM-EDX investigations and (ii) thermodynamic calculations. The SEM-EDX analysis of the steel/ceramic interface shows the chemical degradation of the hBN-SiC-ZrO 2 -substrate. As a result of the reaction, a transition layer with a thickness of around 0.7 mm was formed in the hBN-SiC-ZrO 2 -substrate. To characterize the chemical reaction, thermodynamic calculations were conducted using the Thermo-Calc software. Results show that the chemical reaction was caused by the chemical instability of the SiC with regard to elements in Cr–Mn–Ni-alloys. [ABSTRACT FROM AUTHOR]

Sequential reactive systems include programs and devices that work with two streams of data and convert input streams of data into output streams. Such information processing systems include controllers, device drivers, computer interpreters. The result of the operation of such computing systems are infinite sequences of pairs of events of the request-response type, and, therefore, finite transducers are most often used as formal models for them. The behavior of transducers is represented by binary relations on infinite sequences, and so, traditional applied temporal logics (like HML, LTL, CTL, mu-calculus) are poorly suited as specification languages, since omega-languages, not binary relations on omega-words are used for interpretation of their formulae. To provide temporal logics with the ability to define properties of transformations that characterize the behavior ofreactive systems, we introduced new extensions ofthese logics, which have two distinctive features: 1) temporal operators are parameterized, and languages in the input alphabet oftransducers are used as parameters; 2) languages in the output alphabet oftransducers are used as basic predicates. Previously, we studied the expressive power ofnew extensions Reg-LTL and Reg-CTL ofthe well-known temporal logics oflinear and branching time LTL and CTL, in which it was allowed to use only regular languages for parameterization of temporal operators and basic predicates. We discovered that such a parameterization increases the expressive capabilities oftemporal logic, but preserves the decidability of the model checking problem. For the logics mentioned above, we have developed algorithms for the verification of finite transducers. At the next stage of our research on the new extensions of temporal logic designed for the specification and verification of sequential reactive systems, we studied the verification problem for these systems using the temporal logic Reg-CTL*, which is an extension ofthe Generalized Computational Tree Logics CTL*. In this paper we present an algorithm for checking the satisfiability of Reg-CTL* formulae on models of finite state transducers and show that this problem belongs to the complexity class ExpSpace.

Sequential reactive systems include hardware devices and software programs which operate in continuous interaction with the external environment, from which they receive streams of input signals (data, commands) and in response to them form streams of output signals. Systems of this type include controllers, network switches, program interpreters, system drivers. The behavior of some reactive systems is determined not only by the sequence of values of input signals, but also by the time of their arrival at the inputs of the system and the delays in computing the output signals. These aspects of reactive system computations are taken into account by real-time models of computation which include, in particular, realtime finite state machines (TFSMs). However, in most works where this class of real-time automata is studied a simple variant of TFSM semantics is used: the transduction relation computed by a TFSM is defined so that the elements of an output stream, regardless oftheir timestamps, follow in the same order as the corresponding elements ofthe input stream. This straightforward approach makes the model easier to analyze and manipulate, but it misses many important features of real-time computation. In this paper we study a more realistic semantics of TFSMs and show how to represent it by means of Labeled Transition Systems. The use of the new TFSM model also requires new approaches to the solution of verification problems in the framework of this model. For this purpose, we propose an alternative definition of TFSM computations by means of Labeled Transition Systems and show that the two definitions of semantics for the considered class of real-time finite state machines are in good agreement with each other. The use of TFSM semantics based on Labeled Transition Systems opens up the possibility of adapting well known real-time model checking techniques to the verification ofsequential reactive systems.

Introduction. Verification packages design and analyze the correctness of parallel and distributed systems within the framework of various classes of temporal logics of linear and branching time. The paper discusses a polynomially realizable class of ∆0T -formulas interpreted on multi-sorted models with hierarchical suspensions. The suspensionstructure is described by an arbitrary context-free (CF) grammar. The predicates and functions of the model signature are interpreted on the original CF-list, which is completed during the interpretation process.Materials and Methods. A constant model is constructed for theories from ∆0T-quasiidentities with Noetherian and confluence properties. We consider formulas of the multi-sorted first-order predicate calculus (PC) language with variables of the “list” sort interpreted on models with a hierarchized suspension. The theory is interpreted in terms of grammar inference trees describing the behavior of the specified system. The CF-grammar rules hierarchize the action space of the modeled system. It is noted that the expressive capabilities of Д0T-formulas are insufficient for modeling real-time systems. Therefore, expressions with unbounded universal quantifier V, known as PT formulas, are used for the specification.Results. The logical specification of an automated complex which consists of a workpiece manipulator is given as an example. The location of the positions is fixed by sensors. The operating cycle of the manipulator is described. The specification of its operation consists in the hierarchization of actions by the rules of the CF-grammar and their description by the first-order PT-formulas taking into account the time values.Discussion and Conclusions. The paper shows that the class of the considered formulas can be used to model real-time systems. An example of the logical specification of a manipulator behavior control device is given.

Sequential reactive systems include programs and devices that work with two streams of data and convert input streams of data into output streams. Such information processing systems include controllers, device drivers, computer interpreters. The results of operation of such computing systems are infinite sequences of pairs of events of the request-response type, and, therefore, finite transducers are most often used as formal models for them. The behavior of transducers is represented by binary relations on infinite sequences, and so, traditional applied temporal logics (like HML, LTL, CTL, mu-calculus) are poorly suited as specification languages, since omega-languages, not binary relations on omega-words are used for interpretation of their formulas. To provide temporal logics with the ability to define properties of transformations that characterize the behavior of reactive systems, we introduced new extensions of these logics, which have two distinctive features: (1) temporal operators are parameterized, and languages in the input alphabet of transducers are used as parameters; (2) languages in the output alphabet of transducers are used as basic predicates. Previously, we studied the expressive power of new extensions Reg-LTL and Reg-CTL of the well-known temporal logics of linear and branching time LTL and CTL, in which it was allowed to use only regular languages for parameterization of temporal operators and basic predicates. We discovered that such a parameterization increases the expressive capabilities of temporal logic, but preserves the decidability of the model checking problem. For the logics mentioned above, we have developed algorithms for the verification of finite transducers. At the next stage of our research on the new extensions of temporal logic designed for the specification and verification of sequential reactive systems, we studied the verification problem for these systems using the temporal logic Reg-CTL*, which is an extension of the generalized computational tree logics CTL*. In this paper we present an algorithm for checking the satisfiability of Reg-CTL* formulas on models of finite state transducers and show that this problem belongs to the complexity class ExpSpace. [ABSTRACT FROM AUTHOR]

Sequential reactive systems include hardware devices and software programs which operate in continuous interaction with the external environment, from which they receive streams of input signals (data, commands) and in response to them form streams of output signals. Systems of this type include controllers, network switches, program interpreters, system drivers. The behavior of some reactive systems is determined not only by input sequences, but also by their timestamps and the delays in computing the output signals. These aspects of reactive system computations are taken into account by real-time models of computation which include, in particular, real-time finite state machines (TFSMs). However, in most works where this class of real-time automata is studied, a simple variant of TFSM semantics is used: the transduction relation computed by a TFSM is defined so that the elements of an output stream, regardless of their timestamps, follow in the same order as the corresponding elements of the input stream. This straightforward approach makes the model easier to analyze and manipulate, but it misses many important features of real-time computation. In this paper we study a more realistic semantics of TFSMs and show how to represent it by means of labeled transition systems. The use of the new TFSM model also requires new approaches for the solution of verification problems in the framework of this model. For this purpose, we suggest an alternative definition of TFSM computations by means of labeled transition systems and show that the both definitions of semantics for the considered class of real-time finite state machines are in good agreement with each other. The use of TFSM semantics based on labeled transition systems opens up the possibility of adapting well-known real-time model checking techniques to the verification of sequential reactive systems. [ABSTRACT FROM AUTHOR]

Although there are e-health systems for the care of elderly people, the reactive characteristics to enhance scalability and extensibility, and the use of this type of system in smart cities, have been little explored. To date, some studies have presented healthcare systems for specific purposes without an explicit approach for the development of health services. Moreover, software engineering is hindered by agile management challenges regarding development and deployment processes of new applications. This paper presents an approach to develop health Internet of Things (IoT) reactive applications that can be widely used in smart cities for the care of elderly individuals. The proposed approach is based on the Rozanski and Woods's iterative architectural design process, the use of architectural patterns, and the Reactive Manifesto Principles. Furthermore, domain-driven design and the characteristics of the emerging fast data architecture are used to adapt the functionalities of services around the IoT, big data, and cloud computing paradigms. In addition, development and deployment processes are proposed as a set of tasks through DevOps techniques. The approach validation was carried out through the implementation of several e-health services, and various workload experiments were performed to measure scalability and performance in certain parts of the architecture. The system obtained is flexible, scalable, and capable of handling the data flow in near real time. Such features are useful for users who work collaboratively in the care of elderly people. With the accomplishment of these results, one can envision using this approach for building other e-health services. [ABSTRACT FROM AUTHOR]

My interest in scientific metaphor focuses on its role in charting our search for knowledge of a world not yet known. How else is one to seek understanding of the new, of the not yet intelligible, if not by comparison with what is already familiar? But comparison is hardly enough; a useful guide to the unknown must also keep us mindful of the strangeness, the incomparability, of novelty. Metaphor accrues its value in the instability it generates by confronting similarity with difference, insisting that man both is and is not a wolf. Lose this duality, and one loses the vitality of the metaphor. My question is almost mundane: how do the particular metaphors scientists invoke shape their view of the natural world? How would that knowledge be different had it been guided by different choices? Are there features made salient by one metaphor that lose significance in the framework invited by another? How is our scientific picture of the world shaped by the metaphors we choose to guide our search? To what other discoveries might different choices have led us? [ABSTRACT FROM AUTHOR]

Finite state transducers over semigroups are regarded as a formal model of sequential reactive programs that operate in the interaction with the environment. At receiving a piece of data a program performs a sequence of actions and displays the current result. Such programs usually arise at implementation of computer drivers, on-line algorithms, control procedures. In many cases verification of such programs can be reduced to minimization and equivalence checking problems for finite state transducers. Minimization of a transducer over a semigroup is performed in three stages. At first the greatest common left-divisors are computed for all states of the transducer, next the transducer is brought to a reduced form by pulling all such divisors ”upstream”, and finally a minimization algorithm for finite state automata is applied to the reduced transducer.

In order to develop reliable software and systems, we depend on practical techniques for the construction and analysis of such software and systems. This special issue of Software Tools for Technology Transfer presents various tool-supported techniques that can help with the construction and analysis of such reliable software and systems. The papers in this special issue are extended versions of selected conference papers from the proceedings of the 24th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS 2018). [ABSTRACT FROM AUTHOR]

Finite state transducers over semigroups are regarded as a formal model of sequential reactive programs that operate in the interaction with the environment. At receiving a piece of data a program performs a sequence of actions and displays the current result. Such programs usually arise at implementation of computer drivers, on-line algorithms, control procedures. In many cases verification of such programs can be reduced to minimization and equivalence checking problems for finite state transducers. Minimization of a transducer over a semigroup is performed in three stages. At first the greatest common left-divisors are computed for all states of a transducer, next a transducer is brought to a reduced form by pulling all such divisors "upstream," and finally a minimization algorithm for finite state automata is applied to the reduced transducer. [ABSTRACT FROM AUTHOR]