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In the development and verification of safety-critical and safety-related Instrumentation and Control (I&C) systems, it is essential to ensure there is no deviation from the requirements of the assignment during development. Model checking is a method of formal verification which can be used to prove whether a formal model satisfies its formal requirement. Since algorithms of I&C systems are generally informal, they can not be verified by model checking directly, but they must be carefully translated. This article presents a new method based on functionally-equivalent formalisation and model checking. This method can be used for automatic verification of I&C algorithms by model checking while preserving obtained proofs from a formalised model in the original algorithm. There are several problems associated with the verification of PLCs by model checking: 1) State space explosion, 2) Model consistency, 3) Specifying Properties to be Checked, 4) Representing PLC execution cycle, 5) TONs timers representation. This aims of this article is to address points 1), 2), 4) and 5). The article also presents conditions for implementing these algorithms in a target I&C system under which the obtained proofs can also be expected in the physical I&C system. This article primarily focuses on formalisation and model checking of Function Block Diagram (FBD) algorithms. However, the presented methods can also be extended to other programming languages.

A purposely naïve and semi-empirical model allows for the reproduction of the phenomenological behavior of any real microbial culture by adjusting the values of three parameters, which have a biological meaning only for a virtual microbial culture that mimics the behavior of the real ones. Any genomic, biochemical, and physical peculiarity (microbial species, physiological condition, pH, water activity, temperature, etc.) that distinguishes one real culture from another is "translated" to an effect of the degree of progress of the population density and cell age in the virtual culture. The model leads to a self-consistent description of the growth curve, which looks like the result of an autocorrelation effect. This explains why, in spite of genomic and physiologic differences, all the growth curves show a sigmoid trend. The traditional growth curve and the subsequent exponential decay in the log(N)-vs-t plot can be replaced by straight-line trends when referring to the degree of progress of the population density of the virtual culture. [ABSTRACT FROM AUTHOR]

This paper develops a model of voter turnout that embeds Riker and Ordeshooks (1968 Am. Pol. Sci. Rev. 62, 25-42 (doi:10.2307/1953324)) calculus of voting into the context of a social network. In the model, an individuals expressive benefits to voting depend on the behaviour of their social contacts. We show that there may be multiple equilibria and analyse how these equilibria depend on the structure of the network. We discuss six empirical implications of the model for turnout, some of which suggest novel answers to longstanding puzzles in the turnout literature, such as: why are higher income individuals more likely to vote even in cases when registration costs are low? Why is turnout so difficult to predict? Why does lowering registration costs disproportionately increase turnout among high-income voters? And why do we observe inertia in turnout across elections?

Verification of real-time system properties using formal models can improve system design and quality. The Timed Petri net is a formal model for modelling and designing real-time systems with time constraints. Furthermore, model checking is a formal verification method used to verify system properties using model checkers. This article proposes an automated transformation system for mapping a Timed Petri net into one of the common model checkers, the SPIN PROMELA model, to verify real-time system properties. This approach enables the combination of two modelling paradigms and supports system verification using system design models. In this study, the system properties were verified using both the simulation method and linear temporal logic formulas supported by the SPIN model checker. Timed Petri net models of two different case studies, a central server computer system and a manufacturing Kanban system were considered to verify the boundedness, liveness and system behavioral properties using the proposed transformation system.

The digital transformation of critical infrastructures, such as energy or water distribution systems, is essential for their smart management. Faster issue identification and smoother services enable better adaptation to consumers' evolving demands. However, these large-scale infrastructures are often outdated. Their digital transformation is crucial to enable them to support societies. This process must be carefully planned, providing guidance that ensures that the data they rely on are dependable and that the system remains fully operational during the transition. This paper presents a formal model that supports reliable data acquisition in legacy critical infrastructures, facilitating their evolution towards a data-driven smart system. Our model provides the foundation for a flexible transformation process while generating dependable data for system management. We demonstrate the model's applicability in a use case within the water distribution domain and discuss its benefits. [ABSTRACT FROM AUTHOR]

The use of agents across diverse domains within computer science and artificial intelligence is experiencing a notable surge in response to the imperatives of adaptability, efficiency, and scalability. The subject of this study is the application of formal methods to furnish a framework for knowledge interpretation with a specific focus on the agent-based paradigm in software engineering. This study aims to advance a formal approach to knowledge interpretation by leveraging the agent-based paradigm. The objectives are as follows: 1) to examine the current state of the agent-based paradigm in software engineering; 2) to describe the basic concepts of the knowledge interpretation approach; 3) to study the general structure of the rule extraction task; 4) to develop the reference structure of knowledge interpretation; 5) to develop a multi-agent system architecture; 6) and to discuss the research results. This study employs formal methods, including the use of closed path rules and predicate logic. Specifically, the integration of closed path rules contributes to the extraction and explication of facts from extensive knowledge bases. The obtained results encompass the following: 1) a rule mining approach grounded in closed path rules and tailored for processing extensive datasets; 2) a formalization of relevance that facilitates the scrutiny and automated exclusion of irrelevant fragments from the explanatory framework; and 3) the realization of a multi-agent system predicated on the synergy among five distinct types of agents, dedicated to rule extraction and the interpretation of acquired knowledge. This paper provides an example of the application of the proposed formal tenets, demonstrating their practical context. The conclusion underscores that the agent-based paradigm, with its emphasis on decentralized and autonomous entities, presents an innovative framework for handling the intricacies of knowledge processing. It extends to the retrieval of facts and rules. By distributing functions across multiple agents, the framework offers a dynamic and scalable solution to effectively interpret vast knowledge repositories. This approach is particularly valuable in scenarios where traditional methods may struggle to cope with the volume and complexity of information.

Verification of real-time system properties using formal models can improve system design and quality. The Timed Petri net is a formal model for modelling and designing real-time systems with time constraints. Furthermore, model checking is a formal verification method used to verify system properties using model checkers. This article proposes an automated transformation system for mapping a Timed Petri net into one of the common model checkers, the SPIN PROMELA model, to verify real-time system properties. This approach enables the combination of two modelling paradigms and supports system verification using system design models. In this study, the system properties were verified using both the simulation method and linear temporal logic formulas supported by the SPIN model checker. Timed Petri net models of two different case studies, a central server computer system and a manufacturing Kanban system were considered to verify the boundedness, liveness and system behavioral properties using the proposed transformation system. [ABSTRACT FROM AUTHOR]

The use of agents across diverse domains within computer science and artificial intelligence is experiencing a notable surge in response to the imperatives of adaptability, efficiency, and scalability. The subject of this study is the application of formal methods to furnish a framework for knowledge interpretation with a specific focus on the agent-based paradigm in software engineering. This study aims to advance a formal approach to knowledge interpretation by leveraging the agent-based paradigm. The objectives are as follows: 1) to examine the current state of the agent-based paradigm in software engineering; 2) to describe the basic concepts of the knowledge interpretation approach; 3) to study the general structure of the rule extraction task; 4) to develop the reference structure of knowledge interpretation; 5) to develop a multi-agent system architecture; 6) and to discuss the research results. This study employs formal methods, including the use of closed path rules and predicate logic. Specifically, the integration of closed path rules contributes to the extraction and explication of facts from extensive knowledge bases. The obtained results encompass the following: 1) a rule mining approach grounded in closed path rules and tailored for processing extensive datasets; 2) a formalization of relevance that facilitates the scrutiny and automated exclusion of irrelevant fragments from the explanatory framework; and 3) the realization of a multi-agent system predicated on the synergy among five distinct types of agents, dedicated to rule extraction and the interpretation of acquired knowledge. This paper provides an example of the application of the proposed formal tenets, demonstrating their practical context. The conclusion underscores that the agent-based paradigm, with its emphasis on decentralized and autonomous entities, presents an innovative framework for handling the intricacies of knowledge processing. It extends to the retrieval of facts and rules. By distributing functions across multiple agents, the framework offers a dynamic and scalable solution to effectively interpret vast knowledge repositories. This approach is particularly valuable in scenarios where traditional methods may struggle to cope with the volume and complexity of information. [ABSTRACT FROM AUTHOR]

Moving Block is a railway signaling concept that paves the way for increasing line capacity while reducing maintenance and operating costs. Its implementation relies on autonomous solutions for train localization, mainly based on GNSS technology. However, the introduction of such technological innovations leads to the emergence of new risks. These risks need to be investigated meticulously, and some confidence level needs to be assigned to GNSS-based localization solutions in railways while considering various settings. The contribution of this paper falls within this context by bringing formal approaches into play in order to evaluate performance and safety properties related to the use of GNSS-based virtual balises for train localization. Specifically, the adopted model-based approach consists in translating the relevant behavior of the localization system through configurable timed and probabilistic automata. The elaborated models being parameterizable, various test scenarios, considering a wide range of configurations, can be investigated. Quantitative and qualitative analysis results can be generated on the basis of our models by means of statistical model-checking algorithms implemented in the UPPAAL-SMC modeling and verification tool. A case study is used to illustrate the application of the presented approach, and various numerical analysis results are provided. As the present contribution implements a model-driven approach to perform safety analysis in railways, it is fully in line with the increasing willingness to reduce recourse to on-site tests in the sector. Such tests are indeed costly and time-consuming, thus jeopardizing the introduction of technical innovations in railways.

This paper develops a model of voter turnout that embeds Riker and Ordeshook’s (1968 Am. Pol. Sci. Rev. 62, 25–42 (doi:10.2307/1953324)) calculus of voting into the context of a social network. In the model, an individual’s expressive benefits to voting depend on the behaviour of their social contacts. We show that there may be multiple equilibria and analyse how these equilibria depend on the structure of the network. We discuss six empirical implications of the model for turnout, some of which suggest novel answers to longstanding puzzles in the turnout literature, such as: why are higher income individuals more likely to vote even in cases when registration costs are low? Why is turnout so difficult to predict? Why does lowering registration costs disproportionately increase turnout among high-income voters? And why do we observe inertia in turnout across elections?

In this article we introduce a formal approach to the evolution of documents with particular attention to the philological perspective and the typical related issues. We propose a mathematical model capable of formalizing various complex phenomena in various research fields such as Computational Linguistics, Digital Philology and Software Engineering, in particular when this is applied to the analysis of documents and texts of historical and literary interest.

The concept of modernizing outdated systems in critical infrastructure through digital transformation has been a widely discussed topic nowadays. Following the transition of energy systems, the attention has now shifted towards digitalizing the water distribution systems. These systems are large-scale but outdated systems that frequently encounter various issues and upgrading them would enable easier to identify issues and provide smoother, more efficient service. However, this process requires cautious planning and guidance to ensure that the generated data is reliable, and the system remains operational during the transition. Hence, the primary objective of this paper is to propose a formal model based on ternary relational semantics that can guide the digital transformation of water distribution networks. The proposed model provides a flexible transformation process while making the system generate reliable data. Additionally, this paper demonstrates the application of the proposed model by developing a proof of concept based on a real-world scenario. [ABSTRACT FROM AUTHOR]

The modern smart grid (SG) is mainly a cyber-physical system (CPS), combining the traditional power system infrastructure with information technologies. SG is frequently threatened by cyber attacks such as False Data Injection (FDI), which manipulates the states of power systems by adding malicious data. To maintain a reliable and secure operation of the smart grid, it is crucial to detect FDI attacks in the system along with their exact location. The conventional Bad Data Detection (BDD) algorithm cannot detect such stealthy attacks. So, motivated by the most recent deep learning (DL) developments and data-driven solutions, a new transformer-based model named XTM is proposed to detect and identify the exact locations of data intrusions in real-time scenarios. XTM, which combines the transformer and long short-term memory (LSTM), is the first hybrid DL model that explores the performance of transformers in this particular research field. First, a new threshold selection scheme is introduced to detect the presence of FDI, replacing the need for conventional BDD. Then, the exact intrusion point of the attack is located using a multilabel classification approach. A formally verified constraints satisfaction-based attack vector model was used to manipulate the data set. In this work, considering the temporal nature of power system, both hourly and minutely sensor data are used to train and evaluate the proposed model in the IEEE-14 bus system, achieving a detection accuracy of almost 100%. The row accuracy (RACC) metric was also evaluated for the location detection module, with values of 92.99% and 99.99% for the hourly and minutely datasets, respectively. Moreover, the proposed technique was compared with other deep learning models as well, showing that the proposed model outperforms the state-of-the-art methods mentioned in the literature. [ABSTRACT FROM AUTHOR]

Illegal software manipulation is one of the biggest issues in software security. This includes the legally relevant software which are now crucial modules in weight and measuring instruments such as weighbridges. Despite the advancement and complexity of weight and measuring instruments, the inspection methodology is weak and lacks of innovation. The conventional inspection method is merely based on the observation printed certificate of the software. This paper introduces Malaysia Software-Assisted Non-Automatic Weighing Instrument (NAWI) Inspection (MySANI), a method used to enhance the software inspection scheme in legal metrology. MySANI introduces security objects in order to assist and enhance the inspection process. The security evaluation is based on the best practices in IT in metrology, where the attack model on relevant assets of the security objects is simulated for the Attack Probability Tree. The attack tree is verified by integrating formal notation and comparison with finite state transition system domain to verify the correctness properties of the tree design before the model can be further used in a risk analysis procedure within the Attack Probability Tree framework. Results show that the designed attack tree is consistent with the designed simulation. [ABSTRACT FROM AUTHOR]

The properties of dynamic interactions in mobile-interactive systems are still difficult to analyze because of the complexity of systems. Thus, we have proposed a new Petri net called the variable petri net (VPN) recently, which specializes in describing dynamic interactions in systems. To make better use of VPN, this article focuses on the model checking method of VPN. It introduces the algorithm to transform a VPN to a Kripke structure that can describe both the system running states and the system connection states in VPN, and the method to transform a property to a temporal logic formula based on VPN and its Kripke structure. The Kripke structure can be optimized by considering the specific property about the system connection states and then be used to perform the targeted verification to the property by using a model checker. A practical example is given to demonstrate the proposed methods. [ABSTRACT FROM AUTHOR]

This work presents formal modeling of Network-on-Chip (NoC) considering detailed functional units of NoC. The intricate modeling of NoC router components like buffer, switch, and arbiter is accomplished using Finite State Machine (FSM). As in the case of a real NoC, parallel execution of these functional units is carried out by maintaining the synchronization between these functional units within a router and between each of the adjacent routers in the presented formal model. Important properties for the correctness of the proposed model are verified using a model checker. Implementing a detailed and a complete NoC model is a memory extensive operation while verifying with a model checker. We have introduced a concept of active windows to verify each router and its communication with the adjacent routers. The correctness of the model is checked by verifying the synchronization between NoC functional units and NoC routers, verifying progress in functional units, and verifying the successful transfer of packets. Verification of starvation freedom in an NoC router is also performed for round-robin arbiter and fixed-priority arbiter. Parallel threads are used in the experiments to reduce the verification time.

The graphical modeling language GRAFCET is used as a formal specification language in industrial control design. To use these formal specifications for model-driven development of control code it is beneficial to ensure their syntactical and semantic correctness. Therefore in this paper, a detailed meta-model for GRAFCET is presented, which takes so-called terms into account, i.e. logical and arithmetic expressions in conditions and assignments. The meta-model and additionally proposed invariants allow the creation of syntactically correct GRAFCET instances. Based on this, a translation of GRAFCET to Guarded Action Language (GAL) is presented. The resulting transition system in GAL forms the basis for a semantic analysis of the GRAFCET instances by means of model checking in future research. Finally, the models are then employed for automatic code generation in Structured Text.

With sensors becoming increasingly ubiquitous, there is tremendous potential for Internet of Things (IoT) services that can take advantage of the data collected by these sensors. Although there are a growing number of technologies focused on IoT services, there is relatively limited foundational work on them. This is partly because of the lack of precise understanding, specification, and analysis of such services, and, consequently, there is limited platform support for programming them. In this paper, we present a formal model for understanding and enabling reasoning about distributed IoT services. The paper first studies the key properties of the IoT services profoundly, and then develops an approach for fine-grained resource coordination and control for such services. The resource model identifies the core mechanisms underlying IoT services, informing design and implementation decisions about them if implemented over a middleware or a platform. We took a multi-agent systems approach to represent IoT services, broadly founded in the actors model of concurrency. Actor-based services can be built by composing simpler services. Furthermore, we created a proximity model to represent an appropriate notion of IoT proximity. This model represents the dynamically evolving relationship between the service's sensing and acting capabilities and the environments in which these capabilities are exercised. The paper also presents the design of a runtime environment to support the implementation of IoT services. Key mechanisms required by such services will be implemented in a distributed middleware. [ABSTRACT FROM AUTHOR]

The potential of the Internet and related digital technologies, such as the Internet of Things (IoT), cognition and artificial intelligence, data analytics, services computing, cloud computing, mobile systems, collaboration networks, and cyber-physical systems, are both strategic drivers and enablers of modern digital platforms with fast-evolving ecosystems of intelligent services for digital products. This issue of CSIMQ presents three recent articles on modern software engineering. First, we focus on continuous software development and place it in the context of software architectures and digital transformation. The first contribution is followed by the description of the basis of specific security requirements and adequate digital monitoring mechanisms. Finally, we present a practical example of the digital management of livestock farming.

Dominance, hostility and autonomy are interpersonal phenomena that emerge from the complex dyadic interplay of two individuals reciprocally influencing each other. Assessing the complexity of interpersonal interactions usually involves its reduction, for example with self-report and observer-rated measures informed by the structural analysis of social behavior (SASB). In contrast, letting individuals generate a complex stream of interpersonal experience and behavior from moment to moment is an empirical approach not yet usual in interpersonal theory. In the present study, we developed and evaluated an interpersonal, generative paradigm that allows participants to interact nonverbally and spontaneously with a computer-controlled other player in real-time without the need for introspection or the capacity to verbalize potentially implicit interpersonal processes. In the game-like paradigm, participants use the keyboard to take over objects such as a handcar to move autonomously around and encounter interfering or freedom granting artificial other players. We expected that participants (1) experience the nonverbal so-called game mechanics of the paradigm as interpersonal in nature, (2) behave towards the other players in an interpersonally complementary way, and (3) are influenced by their own trait interpersonal expectations. During the paradigm, 40 participants appraised the majority of the game mechanics and computer-controlled other players as intended. Also, interpersonal traits affected the spontaneous behavior towards artificial characters. These findings corroborate the feasibility and validity of a generative assessment of interpersonal dynamics beyond self-reports and observer ratings. The paradigm paves the way for the empirical testing of formal, computational models of dyadic interaction.

Mobile computing systems, service-based systems, and some other systems with mobile interacting components have recently received much attention. However, because of their characteristics, such as mobility and disconnection, it is difficult to model and analyze them by using a structure-fixed model. This work proposes a new Petri net model called variable Petri net (VPN) for modeling and analyzing these systems. The definition, firing rule, and related analysis technology of VPN are introduced in detail. In a VPN, the possible interaction interfaces are abstracted as a new kind of places called virtual places, and the occurrences of (dis)connections are described by new functions, which makes it appropriate to describe the component collaboration in systems and realize the scalability and pluggability of systems. Moreover, to overcome the shortcoming that markings cannot reflect the link capability of a system, VPNs add a constraint function along with a marking to represent a complete system configuration. Several examples are used to demonstrate the newly proposed model and method. [ABSTRACT FROM AUTHOR]

Nowadays, The Internet of Things(IoT) has shown an increased interest in the academic literature, while its implementations became involved in almost every aspect of life in modern society. IoT is the integration of virtual and physical things through distributed services to collect and share data among themselves. The number of architecture approaches designed to aid IoT has increased significantly recently. As a result of different IoT architecture approaches, in this paper, we proposed a novel correct-by-construction formal approach based on an Event-B method to describe the physical architecture of IoT layers. This formal approach inspects four layers: the physical layer, the gateway layer, the middleware layer, respectively the application layer. An Electrocardiogram (ECG) IoT system is applied in our model as a case study. Finally, we proved and validated the correctness of our formal model by using proof obligations and the model checking tool called Rodin. [ABSTRACT FROM AUTHOR]

The use of a visual analytical system in machine learning is the basis for the integration of human and the use of his intellectual capabilities in the construction of models. At the same time, visual analytics is used to expand human knowledge and is used as a research tool. We investigate the forms and goals of using visual analytics workflow toward the formation of the final product. Workflow is divided into human‐oriented and machine‐oriented in order to build a model as an information processor and decision‐making mechanism. Models are built on the basis of the end user, which can be either a machine or a human. The concepts of model building and the role of machines and humans in these processes are investigated. A practical implementation of the classification information technology in the studied concept "using opposite model" in the machine‐oriented visual analytics workflow for using the machine model is proposed. The basis for this model is a model formed and used by human. To classify data, human intellectual abilities are used. The boundaries of classes are determined by a human and then projected into a hyperspace of attributes with the formation of a classification model that the machine uses. Information technology allows the machine to use a model built for humans. [ABSTRACT FROM AUTHOR]

Pipe internal pressure measurement is of utmost importance in the oil & gas industry to monitor the extraction process, and thus to prevent hydrate-plugs formation which may occur in specific temperature and pressure conditions. Traditional solutions usually rely on pressure sensors in direct contact with the fluid to monitor, therefore requiring one hole per sensor, but they also weaken the pipe structure, which may prematurely lead to significant leaks. Attempts to develop non-intrusive pressure sensors relying, for instance, on acoustic waves detection or even strain measurements (the pipe wall acting, in some way, like the membrane of a traditional intrusive sensor), are up to now not fully satisfying, mainly due to poor temperature cross-sensitivity compensation. Thus, 1 °C temperature compensation error typically leads for Fiber Bragg Grating (FBG) transducers to pressure measurement biases greater than 26% at 100 bar (e.g.: Ø 4" NPS Sch. 160 steel pipe). Consequently, if such non-intrusive, but biased, solutions could possibly have been considered to monitor, for instance, a Nuclear Power Plant (NPP) primary coolant circuit, it was with the risk of dramatic consequences since the fluid can reach temperatures up to 320 °C. On the other hand, the solution detailed here truly achieves to cancel the temperature cross-sensitivity, and potentially any additional effect on pressure measurement, provided that each effect has the same influence on all transducers. It first relies on a better understanding of the pipe behavior under hydrostatic pressure, supported by a dedicated model developed on purpose, which demonstrates that the internal pressure and the surface temperature variations of a closed pipe can be recovered with at least two direction-sensitive transducers, the temperature dependence of the pressure measurement being simply removed by a straightforward compensation process. This paper explains the underlying principle, thanks to a formal model established with only few hypotheses, but extended to more complex field conditions. It ends with a lab-test validation involving FBG transducers attached to a pressure circuit submitted to temperature variations greater than several tens of °C, and concludes about the advantages and limitations of this novel approach for non-intrusive sensing, and its potential extensions to other measurement techniques. [ABSTRACT FROM AUTHOR]

What should the managers of a multibusiness firm do when their company's resources are not used profitably? Research on redeployment proposes that managers should withdraw those resources from the business where they are underutilized and switch them to a business where they can be used more profitably, whereas the literature on divestiture advocates that managers should divest the business containing those resources. In this study, we investigate the factors that lead managers to choose resource redeployment over divestiture as a mode of exit and vice versa. Using a formal model, we establish that the two exit modes act as intertemporal substitutes, whereby redeployment dominates for earlier exits but divestiture dominates for later exits. Although both redeployment and divestiture are inversely related to their implementation costs, redeployment costs amplify the effect of divestiture costs on the likelihood of exit, and divestiture costs amplify the effect of redeployment costs on the likelihood of exit. Finally, we derive a series of results that show that disregarding one of these two exit options as a strategic alternative to the other may lead to misspecifications of empirical models that seek to predict the likelihood of redeployment, divestiture, or exit. Overall, our work contributes to the corporate strategy literature by uniting two streams of research that have largely remained disparate, yet whose insights have significant implications for each other. [ABSTRACT FROM AUTHOR]

One of the most important issues in the Cloud environment is to adapt to increasing or decreasing customer demands. The demand on Cloud services varies depending on user needs. To meet this need, Cloud services must increase/decrease their capacities according to users demands in a restraint time interval. Therefore, Cloud services have to evolve continuously by scaling up/down their capacity to handle new demands. In this paper, we particularly focus on Cloud composite services that are able to deal with complex users demands. In this context, we propose a formal model based on the Event-B method to manage the dynamic reconfiguration of composite services in the Cloud context. It is a correct by construction model for the management of Cloud resources. It enables to respond to the dynamic user's demands by dynamically reconfiguring the required Cloud resources. The proposed model contains four abstraction levels and implements the scaling mechanisms at each abstraction level. The model consistency has been proved thanks to the Event-B dedicated tools. [ABSTRACT FROM AUTHOR]

Pipe internal pressure measurement is of utmost importance in the oil & gas industry to monitor the extraction process, and thus to prevent hydrate-plugs formation which may occur in specific temperature and pressure conditions. Traditional solutions usually rely on pressure sensors in direct contact with the fluid to monitor, therefore requiring one hole per sensor, but they also weaken the pipe structure, which may prematurely lead to significant leaks. Attempts to develop non-intrusive pressure sensors relying, for instance, on acoustic waves detection or even strain measurements (the pipe wall acting, in some way, like the membrane of a traditional intrusive sensor), are up to now not fully satisfying, mainly due to poor temperature cross-sensitivity compensation. Thus, 1 °C temperature compensation error typically leads for Fiber Bragg Grating (FBG) transducers to pressure measurement biases greater than 26% at 100 bar (e.g.: Ø 4” NPS Sch. 160 steel pipe). Consequently, if such non-intrusive, but biased, solutions could possibly have been considered to monitor, for instance, a Nuclear Power Plant (NPP) primary coolant circuit, it was with the risk of dramatic consequences since the fluid can reach temperatures up to 320 °C. On the other hand, the solution detailed here truly achieves to cancel the temperature cross-sensitivity, and potentially any additional effect on pressure measurement, provided that each effect has the same influence on all transducers. It first relies on a better understanding of the pipe behavior under hydrostatic pressure, supported by a dedicated model developed on purpose, which demonstrates that the internal pressure and the surface temperature variations of a closed pipe can be recovered with at least two direction-sensitive transducers, the temperature dependence of the pressure measurement being simply removed by a straightforward compensation process. This paper explains the underlying principle, thanks to a formal model established with only few hypotheses, but extended to more complex field conditions. It ends with a lab-test validation involving FBG transducers attached to a pressure circuit submitted to temperature variations greater than several tens of °C, and concludes about the advantages and limitations of this novel approach for non-intrusive sensing, and its potential extensions to other measurement techniques.

During the Grand Débat national, launched on January 15, 2019, several platforms such as the Grand Débat national (GDN), Le Vrai Débat (VD), or Entendre la France (EF) collected contributions from participants on societal issues. In this article, we present a method for extracting and analyzing lexical networks derived from the text corpora formed by these contributions using the Semantic Atlas geometric model. The method permits to obtain (1) words and profiles shared by the three platforms, as well as words and profiles specific to each of them, (2) for each word, its lexical network. The list of words over-represented in these corpora and shared by the three platforms contains mainly words related to environmental issues and taxation. The lists specific to each of the platforms show distinct profiles. In particular, the GDN corpus shows an over-representation of words related to incivility and respect, as well as words related to environmental issues and the collective, the VD corpus shows an over-representation of terms related to political, governmental, or international organizations, political figures, personal, socio-economic contingencies, privileges, or modes of participation and voting. For EF, whose contributors are young (average age 29), one finds an over-representation of words related to discrimination, tolerance, and behaviours based on environmental concern. Finally, two examples of lexical networks extracted from the GDN corpus are detailed: that of the word transport (“transport”) and that of the word contre (“against”). For the word contre – chosen because its lexical network reveals which topics matter to the contributors – we show that the method makes explicit and synthesizes semantic links and reveals their organization. It can be seen from this example that environmental issues are an organizing center around which the main topics addressed by the contributors are articulated.

Illegal software manipulation is one of the biggest issues in software security. This includes the legally relevant software which are now crucial modules in weight and measuring instruments such as weighbridges. Despite the advancement and complexity of weight and measuring instruments, the inspection methodology is weak and lacks of innovation. The conventional inspection method is merely based on the observation printed certificate of the software. This paper introduces Malaysia Software-Assisted Non-Automatic Weighing Instrument (NAWI) Inspection (MySANI), a method used to enhance the software inspection scheme in legal metrology. MySANI introduces security objects in order to assist and enhance the inspection process. The security evaluation is based on the best practices in IT in metrology, where the attack model on relevant assets of the security objects is simulated for the Attack Probability Tree. The attack tree is verified by integrating formal notation and comparison with finite state transition system domain to verify the correctness properties of the tree design before the model can be further used in a risk analysis procedure within the Attack Probability Tree framework. Results show that the designed attack tree is consistent with the designed simulation.

An Advanced Metering Infrastructure (AMI) comprises a large number of smart meters along withheterogeneous cyber-physical components that are interconnected through different communication media,protocols, and delivery modes for transmitting usage reports or control commands between meters andthe utility. Due to misconfigurations or lack of security controls, there can be operational disruptionsleading to economic damage in an AMI. Therefore, the resiliency of an AMI is crucial. In this paper, wepresent an automated configuration synthesis framework that mitigates potential threats by eliminatingmisconfigurations and keeps the damage limited under contingencies by introducing robustness. Weformally model AMI configurations, including operational integrity and robustness properties consideringthe interdependencies among AMI devices’ configurations, attacks or failures, and resiliency guidelines.We implement the model using Satisfiability Modulo Theories (SMT) and demonstrate its execution on anexample case study that illustrates the synthesis of AMI configurations satisfying resiliency requirements. Wealso evaluate the framework on synthetic AMI networks.

The aim of the study is to investigate the possibility of applying Bayesian adaptation algorithms to cognitive systems that perceive the Poisson process of external events.The method of research is the use of stochastic description and synthesis of cognitive systems, including the theory of doubly stochastic Poisson processes and the theory of Bayesian adaptation. The formal definition of cognitive systems in the state space in the spirit of similar definitions of the theory of dynamic systems is formulated. The definition has become a methodological basis for the development of models of those sets and transformations that are characteristic of cognitive systems. In particular, to describe the stochastic properties of cognitive systems and the possibility of creating an optimal algorithm, the Bayesian approach recognized in a number of philosophical works is applied.The optimal estimate by the criterion of the minimum standard error is, as is known, a posteriori mathematical expectation of a random estimated value, which is applied in this work. In this case, the well- known difficulty of using Bayesian optimal estimation is the need to set a priori probabilities of a random variable in the system under consideration. An adaptive Bayesian estimation algorithm, also known as the empirical Bayesian approach, is used to overcome this problem. According to the above it is believed that at the entrance of the cognitive system, namely in the unconscious in continuous time there are some events that are modeled by random points. The intensity of the appearance of points is determined by a random variable X, the evaluation of which is the task of the cognitive system as a whole. Up to some time in the field of the unconscious the number of random events accumulate (in mathematical language the classifying sample is formed). At some point, an attempt is made to estimate the value of X, i.e. an attempt to move information from the unconscious area of the cognitive system to the conscious, which is a mental act, an act of learning, etc. From a mathematical point of view, such a model of cognitive functioning is the implementation of an adaptive Bayesian approach, which allows to reduce the influence of a priori distribution of an unknown quantity on its evaluation.The described model of the cognitive system is justified by the fact that the value of X is not only random, but also with an unknown a priori distribution, is not observed directly, and in some way must be evaluated by the cognitive system on the basis of the already existing in the unconscious number of events and the last event on the basis of which.The optimal estimation of the random parameter is used to solve the problem of classification of observations, i.e. the optimal verification of the one-sided hypothesis by the Bayesian criterion.As a result of the undertaken consideration the applicability of the developed formal definition of cognitive system for the formulation of various problems of analysis and synthesis of systems is demonstrated. The advantage of the applied model is the minimum amount of a priori information about the processes occurring in the system. One assumption about the Poisson nature of the events occurring at the input of the system was sufficient.The results of a computational experiment on the adaptive estimation of a random parameter with an unknown a priori distribution are presented.In conclusion it is noted that the further development of the study can be a detailed formulation of the mathematical properties of the elements of the cognitive system mentioned in the definition, formulation, solution and interpretation of new mathematical problems of analysis and synthesis.

A formal specification of access control yields a deeper understanding of any operating system, and facilitates performing security analysis of the OS. In this paper, we provide a comprehensive formal specification of access control in Android (ACiA). Prior work is limited in scope, furthermore, recent developments in Android concerning dynamic runtime permissions require rethinking of its formalization. Our formal specification includes three parts, the user-initiated operations (UIOs) and app-initiated operations (AIOs) - which are distinguished based on the initiating entity, and the URI permissions which are utilized in sharing temporary access to data. We also studied the evolution of URI permissions from API 10 (Gingerbread) to API 22 (Lollipop), and a brief discussion on this is included in the paper. Formalizing ACiA allowed us to discover many peculiar behaviors pertaining to ACiA. In addition to that, we discovered two significant issues with permissions in Android which were reported to Google. [ABSTRACT FROM AUTHOR]

An Advanced Metering Infrastructure (AMI) comprises a large number of smart meters along with heterogeneous cyber-physical components that are interconnected through different communication media, protocols, and delivery modes for transmitting usage reports or control commands between meters and the utility. Due to misconfigurations or lack of security controls, there can be operational disruptions leading to economic damage in an AMI. Therefore, the resiliency of an AMI is crucial. In this paper, we present an automated configuration synthesis framework that mitigates potential threats by eliminating misconfigurations and keeps the damage limited under contingencies by introducing robustness. We formally model AMI configurations, including operational integrity and robustness properties considering the interdependencies among AMI devices' configurations, attacks or failures, and resiliency guidelines. We implement the model using Satisfiability Modulo Theories (SMT) and demonstrate its execution on an example case study that illustrates the synthesis of AMI configurations satisfying resiliency requirements. We also evaluate the framework on synthetic AMI networks. [ABSTRACT FROM AUTHOR]

In the field of service-oriented systems, a service is considered as an artifact that has a logical representation. However, the logical boundary of a service is not clearly defined. In particular, it needs to be defined clearly at the design level. Without such a definition, it is not possible to delineate outgoing coupling of a service. It would be difficult to analyze overall static, inter-modular coupling of a service. Further, one cannot devise effective metrics for design characteristics like complexity, cohesion and coupling of a service. A definition that is both technology-agnostic and independent of the physical packaging of a service would be most suitable. This paper defines clearly the logical boundary of a service and makes other improvements to a generic formal model. Thus, it presents a comprehensive formal model that leads to novel metrics and helps in explaining microservices architecture as a special case. [ABSTRACT FROM AUTHOR]

High availability is one of the core properties of Infrastructure as a Service (IaaS) and ensures that users have anytime access to on-demand cloud services. However, significant variations of workflow and the presence of super-tasks, mean that heterogeneous workload can severely impact the availability of IaaS clouds. Although previous work has investigated global queues, VM deployment, and failure of PMs, two aspects are yet to be fully explored: one is the impact of task size and the other is the differing features across PMs such as the variable execution rate and capacity. To address these challenges we propose an attribute-based availability model of large scale IaaS developed in the formal modeling language CARMA. The size of tasks in our model can be a fixed integer value or follow the normal, uniform or log-normal distribution. Additionally, our model also provides an easy approach to investigating how to arrange the slack and normal resources in order to achieve availability levels. The two goals of our work are providing an analysis of the availability of IaaS and showing that the use of CARMA allows us to easily model complex phenomena that were not readily captured by other existing approaches. [ABSTRACT FROM AUTHOR]

We present and solve a new, more accurate model of behavior within alliance activity. The model is essentially an iterated prisoners' dilemma with an exit option in each stage of the alliance. The proposed solution results in each partner receiving its opportunity cost as its expected average pay-off in the alliance. Managerial implications include: identification of where to focus efforts to improve alliance cooperation and performance; and an explanation for why more sophisticated partnership strategies than tit-for-tat are likely to be superior in this game. [ABSTRACT FROM AUTHOR]

Many learners who are not familiar with the accounting terms find blended learning very complex to understand with respect to the computerized accounting system, the journal entries process, and tracing the accounting transaction flows of accounting system. A simulation-based model is a viable option to help instructors and learners make understanding the accounting system components and monitoring the accounting transactions easier. This paper proposes a colored Petri net (CPN)-based model for the instruction of an accounting system focused on the journal entries processes, accounting modules, and accounting transaction flows. The CPN-based language and the model checking tool named CPN are used to represent the accounting system components: a chart of accounts, an account mapping profile, the journal and ledgers system, and the financial report creations. We evaluated the designed CPN models by creating the simulation cases from ground truth data of the retail department store system and the mortgage loan system, using the decision-table-based testing technique. The results show that the designed CPN model and provided simulation cases help the learners to animate, verify, trace back accounting transactions and data flows, and increase the learner’s understanding.

The definition of the digital humanities has been a matter of heated discussion ever since the introduction of the term, earning the field the dubious reputation of being undefinable. While some seem to take pride in this reputation, the absence of a coherent definition frequently sparks off acrimonious criticism and debates. More importantly, though, it increasingly becomes a liability in the context of the progressive institutionalisation of the digital humanities.Rather than vainly trying to find a definition of digital humanities that is at the same time descriptive and rigorous, we propose a stipulative definition that separates them into theoretical and applied digital humanities: the theoretical digital humanities are the metascientific discipline whose goal is the conception of formal methods that the applied digital humanities use to create formal models in the various humanities disciplines.

The paper presents the UAREI (User-Action-Rule-Entities-Interface) model for formal specification of software gamification, and the UAREI visual modelling language for graphical representation of game mechanics. A case of study in gamification of the Trogon project management system is presented. The proposed model and visual language is compared against the Machinations gamification framework using visual complexity metrics, game simulation and qualitative comparison.

Peer-to-peer (P2P) electronic commerce has become increasingly popular over the last few years. This popularity of P2P is due mainly to the many advantages it offers, such as the ease of sharing of computer resources and reducing cost. This paper uses both semi-formal and formal specification methods to model a P2P digital product marketplace. First, models are written in UML, as this is expected to be relatively easy to understand and economic. Then, the models are transformed into a formal notation, object-Z notation. A formally specified and verified model of e-commerce transactions will provide a correct, fail-safe, and robust transaction processing environment for e-commerce. By using both semi-formal and formal methods in the design of the P2P system, we can reason about and create a correct and reliable system quickly and efficiently.

In this research, we focus on designing an interactive tool which will be used as an aid in learning how to manage emotions during argumentative dialogues. To this end, a collection of examples illustrating the typical human's reactions was collated and used to explain mechanisms that appear in dialogues. We present a theoretical background of the project, i.e., a formal system to represent the change of intensity of emotions in argumentative dialogues. We rely here on persuasive dialogue games. A formal language for expressing properties of protocols for dialogues with emotional reasoning is proposed. We suggest that awareness of emotions improves communication between parents and children, and that it is an important element of both raising communication skills in adults and development of communication skills in children. [ABSTRACT FROM AUTHOR]

Abstract Many metrics have been proposed to measure coupling—the degree of association between modules in a system. They have often been described in different ways, hindering comparison and research. Their definitions are often incomplete regarding language features in some languages, meaning that different tool developers may implement the same metric differently. This complicates comparing results from studies that use different tools. This paper therefore aims to define coupling metrics consistently and unambiguously. The paper describes a model of coupling that uses the reification of the concept of dependency as its fundamental unit. Based on this model, it defines a framework for defining coupling metrics. It shows how to define several well-known coupling metrics in the framework, and how defining different metrics based on the same model facilitates direct comparisons. It discusses how the framework resolves issues due to incomplete metric definitions, such as different language features. This formal framework is sufficiently simple that it can be implemented in such a way as to provide multiple metrics. [ABSTRACT FROM AUTHOR]

Die-stacking technology enables the use of a high density DRAM as a cache. Major processor vendors have recently started using these stacked DRAM modules as the last level cache of their products. These stacked DRAM modules provide high bandwidth with relatively low latency compared to the off-package DRAM modules. Recent studies on DRAM caches propose several variants to optimize performance and power of the systems. However, none of the existing works discuss its design and verification aspect. DRAM cache controller (DCC) design is significantly complex in comparison to a conventional DRAM-based main memory controller. This is because it involves controlling both the timing aspect of DRAM system as well as the functional aspect of cache. Therefore, without rigorous modeling and verification of such designs, it would be difficult to ensure correctness. In the current research, we focus on the design and verification issues of DCC. We select a common variant of DRAM cache and build a formal model of its controller in terms of interacting state machines; we term the common variant as the baseline and its model as the base model. We then verify safety, liveness, and timing properties of this variant using model checking. Next, we demonstrate how the formal models and the associated properties of other variants of DCCs can be derived from the base model in a systematic way. Analyzing the individual DRAM cache variations, we observe that most of the variants exhibit product-line characteristics. [ABSTRACT FROM AUTHOR]