Discrete Event System Specification Research Articles

Method for Detecting Modification of Transmitted Message in C/C++ Based Discrete Event System Specification Simulation

Method for Detecting Modification of Transmitted Message in C/C++ Based Discrete Event System Specification Simulation

A DEVS-based engine for building digital quadruplets.

Development of Embedded Real-Time Systems is prone to error, and developing bug-free applications is expensive and no guarantees can be provided. We introduce the concept of Digital Quadruplet which includes: a 3D virtual representation of the physical world (a Digital Twin), a Discrete-Event formal model of the system of interest (called the “Digital Triplet”), which can be used for formal analysis as well as simulation studies, and a physical model of the real system under study for experimentation (called the “Digital Quadruplet”). We focus on the definition of the idea of a Digital Quadruplet and how to make these four apparati consistent and reusable. To do so, we use the Discrete-Event formal model as a center for both simulation and execution of the real-time embedded components with timing constraints, as well as a common mechanism for interfacing with the digital counterparts, providing model continuity throughout the process. Here we focus on a principal part of the Digital Quadruplet idea: the provision of an environment to allow models to be used for simulation (in virtual time), visualization, or execution in real-time. A Discrete-EVent Systems specifications (DEVS) kernel runs on bare-metal hardware platforms, avoiding the use of an Operating RTOS in the platform, and the combination with discrete-event modeling engineering.

Simulation of a Mobile IoT System Using the DEVS Formalism

This paper proposes two novel methods to model and simulate a mobile Internet of Things (IoT) system using the discrete event system specification (DEVS) formalism. In traditional simulation methods, it is advantageous to partition the simulation area hierarchically to reduce simulation time; however, in this case, the structure of the model may change as the IoT nodes to be modeled move. The proposed methods reduce the simulation time while maintaining the model structure, even when the IoT nodes move. To evaluate the performance of the proposed methods, a prototype mobile IoT system was modeled and simulated. The simulation results show that the proposed methods achieve good performance, even if the number of IoT nodes or the movement of IoT nodes increases.

WSN-SES/MB: System Entity Structure and Model Base Framework for Large-Scale Wireless Sensor Networks.

Large-scale wireless sensor networks are characterized by stringent energy and computation restrictions. It is exceedingly difficult to change a sensor network’s environment configurations, such as the number of sensor nodes, after deployment of the nodes. Although several simulators are able to variously construct simulation models for sensor networks before their deployment, the configurations should be modified with extra human effort as the simulators cannot freely generate diverse models. In this paper, we propose a novel framework, called a system entity structure and model base for large-scale wireless sensor networks (WSN-SES/MB), which is based on discrete event system specification formalism. Our proposed framework synthesizes the structure and models for sensor networks through our modeling construction process. The proposed framework achieves time and cost savings in constructing discrete event simulation-based models. In addition, the framework increases the diversity of simulation models by the process’s pruning algorithm. The simulation results validate that the proposed framework provides up to 8% time savings and up to 23% cost savings as compared to the manual extra effort.

Bringing AI to the edge: A formal M&S specification to deploy effective IoT architectures

ABSTRACT Internet of Things applications are based on ubiquitous networks of multiple distributed devices, with limited computing resources and power, capable of collecting and storing data from heterogeneous sources in real-time. To avoid network saturation and delays, new architectures are needed to provide real-time Big Data and data analytics capabilities at the edge of the network, where energy efficiency needs to be considered to ensure a sustainable and effective deployment in areas of human activity. In this research, we present an IoT model based on the principles of Model-Based Systems Engineering. It covers the description of the entire architecture, from IoT devices to the processing units in edge data centres, and includes the location-awareness of user equipment, network, and computing infrastructures to optimise federated resource management in terms of delay and power consumption. We present a framework to assist the dimensioning and the dynamic operation of IoT data stream analytics applications. Abbreviations : ADAS Advanced Driver Assistance System. 20, 21, 24AI Artificial Intelligence. 2, 24ANN Artificial Neural Network. 2, 21AP Access Point. 5, 10, 11, 12, 13, 17, 18, 19, 20CNF Core Network Function. 5DEVS Discrete Event System Specification. 3, 5, 6, 7, 9, 10, 11, 12, 15, 16, 17, 18, 20, 21, 24, 27, 28EDC Edge Data Centre. 2, 3, 5, 6, 9, 10, 12, 13, 20, 21, 22, 23, 25FaaS Function-as-a-Service. 3, 4, 5, 6FDD Frequency Division Duplexing. 11, 18, 19FSPL Free-Space Path Loss. 20GPU Graphics Processing Unit. 2, 21IoT Internet of Things. 2, 3, 4, 5, 6, 14, 19, 23, 24ISP Internet Service Provider. 5, 10M&S Modelling and Simulation. 3, 24M&S&O Modelling, Simulation, and Optimisation. 21MBSE Model-Based Systems Engineering. 3, 4, 5, 24MCS Modulation and Codification Scheme. 12MDC Micro Data Centre. 2ML Machine Learning. 2, 20, 24, 25NR 5G New Radio. 12P2P Point-to-Point. 5, 10PBCH Physical Broadcast Channel. 19PDCCH Physical Downlink Control Channel. 19PDSCH Physical Downlink Shared Channel. 19PSS Primary Synchronisation Signal. 11, 14PU Processing Unit. 7, 9, 21, 22, 23, 24, 25PUCCH Physical Uplink Control Channel. 19PUSCH Physical Uplink Shared Channel. 19QoS Quality of Service. 2, 4, 5, 6, 12, 24RAN Radio Access Network. 5, 10, 13, 16, 17, 20SDN Software-Defined Network. 5, 10SNR Signal-to-Noise Ratio. 11, 12, 14, 17UE User Equipment. 4, 5, 6, 10, 11, 12, 13, 14, 16, 17, 18, 19, 21, 22, 23, 24, 25WSN Wireless Sensor Network. 4

A new transformation approach for complex systems modelling and simulation: application to industrial control system

Due to the increasing importance of complex systems, the problems of modelling and simulation (M&S) of these systems, their approaches and solutions have been studied extensively these last years. In this paper, we present a novel approach to modelling and simulation of discrete event dynamic systems (DEDS), based on the combination of discrete event systems specification (DEVS) and agent group role (AGR). In this study, the DEVS atomic models are transformed into agents and the DEVS coupled models into groups of agents. Thus, we provide a set of procedures and functions that allow the systematic transformation from DEVS into AGR models in order to be implemented in multi-agent platforms. The proposed approach was validated by a case study, an application in the water supply used in natural gas liquefaction process.

Hierarchical Activity-Based Models for Control Flows in Parallel Discrete Event System Specification Simulation Models

Behavior modeling grounded in the Discrete-Event System Specification (DEVS) and Unified Modeling Language (UML) activity specifications is crucial for simulating dynamical systems. The Model-Driven Architecture (MDA) design approach provides flexible yet rigorous layered metamodels for the UML activity diagrams. Our approach for behavior modeling is focused on the action and control concepts in the UML activity metamodels and realizing them as artifacts according to the DEVS formalism. The syntax and semantics for the artifacts conform to the parallel DEVS model specification and execution protocol. We use the system-theoretic state, component, and hierarchy concepts as the foundation for formulating the DEVS Activity models and supported with a prototype graphical tool developed in Sirius. This research also proposes the Parallel DEVS as a formal approach for examining the semantics of the UML Activities. We develop, simulate, and analyze a set of prototypical multi-processor architecture systems demonstrating different synchronization and selection schemes using the DEVS-Suite and MS4 Me simulators.

Discrete-Event Modeling and Simulation of Diffusion Processes in Multiplex Networks

A variety of phenomena (such as the spread of diseases, pollution in rivers, etc.) can be studied as diffusion processes over networks (i.e., the diffusion of the phenomenon over a set of interconnected entities). This research introduces a method to study such diffusion processes in multiplex dynamic networks. We use a formal Modeling and Simulation methodology (in our case, DEVS, Discrete-Event System Specification). We use DEVS formal models to integrate models defined using Agent-Based Modeling and Network Theory. We present (1) an Architecture to study Diffusion Processes in Multiplex dynamic networks (ADPM) and (2) a systematic Process to define, implement, and simulate diffusion processes over such networks. We show a theoretical definition and a concrete implementation of ADPM. We show how to use ADPM and the process in a case study based on a real nuclear emergency plan; this illustrates the application of the process, the architecture, and the developed software. Different scenarios are studied as Diffusion Processes to demonstrate the usability of ADPM.

A DSDEVS-Based Model for Verifying Structural Constraints in Dynamic Business Processes

This paper presents a DSDEVS-based model “Dynamic Structure Discrete Event System specification” for modeling and simulating business processes with dynamic structure regarding to different contexts. Consequently, this model, formally, improves the reuse of configurable business processes. Thus, the proposed model allows the analysts to personalize their configurable business processes in a sound manner by verifying a set of structure properties, such as, the lack of synchronization and the deadlock by means of simulation. The implementation was done in DEVS-Suite simulator, which is based on DEVSJAVA models.

Simulation Methodology-Based Context-Aware Architecture Design for Behavior Monitoring of Systems

Generally, simulation models are constructed to replicate and predict the behavior of real systems that currently exist or are expected to exist in the future. Once a simulation model is implemented, the model can be connected to a real system for which the model has been built through sensors or networks so that important activities in the real system can be monitored indirectly through the model. This article proposes a modeling formalism BM-DEVS (Behavior Monitor-DEVS) that defines simulation models capable of monitoring the desired behavior patterns within the models so that the target system’s behavior can be monitored indirectly. In BM-DEVS, an extension of classic Discrete Event System Specification (DEVS), the behavior to be monitored is expressed as a set of temporal logic (TL) production rules within a multi-component model that consists of multiple component models to be monitored. An inference engine module for reasoning with the TL rules is designed based on the abstract simulator that carries out instructions in the BM-DEVS models to perform the simulation process. The major application of BM-DEVS is in the design and implementation of the context-aware architecture needed for various intelligent systems as a core constituent. Essentially all systems where some form of behavior monitoring is required are candidate applications of BM-DEVS. This research is motivated by the view that there exists symmetry between the real-world and the cyber world, in that the problems in both environments should be expressed with the same basic constituents of time and space; this naturally leads to adopting spatiotemporal variables composed of simulation models and developing a problem solver that exploits these variables.

DEv-PROMELA: modeling, verification, and validation of a video game by combining model-checking and simulation

Modeling, verifying, and validating are essential steps in order to build systems and software that do what designers expect. If formal verification, and especially model-checking, is a popular method for proving the correctness of properties, its efficiency depends on the accuracy of the used models and the quality of abstractions. As a consequence, applying verification techniques on large-scale complex software like video games is hard without strong assumptions and simplifications. Simulation models are generally more accurate than verification models, but it is often harder to verify them. Combined formalisms that take the benefits of both model-checking and discrete-event simulation represent a good deal between both of these families, although strong engineering expertise remains necessary to define the relevant tests and scenarios. This paper proposes an approach to build this kind of formalism through the example of DEv-PROMELA, which is built by combining Discrete-event System Specification formalism and PROMELA language. Then, it shows how combined formalisms can be used for modeling, verifying, and validating complex software like video games by using both formal-based and simulation-based verification and validation.

Maximal structure generation of superstructure for semantic triple generated by DEVS ontology in the process industry

In the process industry, a large number of multi-source heterogeneous data are generated. Ontology combined with resource description framework (RDF) is a great way to describe multi-source heterogeneous data. Due to the characteristics of free extension, no model limitations and few constraints in the calculation process, semantic data have been increasingly used in industrial systems. However, semantic data have not been fully utilized to realize automatic modeling. Lots of time and experience from knowledge workers is still required in the feedstock scheduling. Therefore, this article presents a method of constructing the RDF triple graph data based on the discrete event system specification ontology. Based on the advantage of graph data, the procedure of superstructure generation is greatly simplified by the proposed RDFMSG (maximal structure generation based on resource description framework data) algorithm. In the RDFMSG algorithm, the original structure is no longer pruned and then reorganized; the superstructure can be generated by the traversing RDF data set only once. The effectiveness and efficiency of the proposed methodology are verified through three cases. In addition, the representation of the discrete event system specification ontology can achieve good performance. Furthermore, the combination explosion caused by set operation can be greatly reduced, indicating that the strategy of the RDFMSG plays an important role in the solution structure generation algorithm and the accelerated branch and bound algorithm.

Layered Behavior Modeling via Combining Descriptive and Prescriptive Approaches: A Case Study of Infantry Company Engagement

Defense modeling and simulation (DMS and prescriptive modeling to discover best individual actions in the reduced space. For the generalization, the proposed method adapts both modeling methods being modularized, and then the proposed method suggested an interface between them that is based on their semantic analogies. Both modeling methods are modularized, so they are interacted through an interface defined in the proposed method. This paper presents a realization of the proposed method through a case study of infantry company-level operations. In the case study, the proposed method is implemented with discrete event system specification formalism as the descriptive part and Markov decision process as the prescriptive part. The experimental results illustrated that the combat effectiveness resulted from the proposed method is statistically better than that from the descriptive-only modeling, and the difference would be guided by the objective of the combat behavior. Through the presented experimental results and the discussion, this paper argues that future DM&S should consider a broad spectrum from the battlefield incorporating the rational behavior of military individuals.

Systematic Detection of State Variable Corruptions in Discrete Event System Specification Based Simulation

Systematic Detection of State Variable Corruptions in Discrete Event System Specification Based Simulation

DEVS-IoT: performance evaluation of smart home devices network

Advances in electronics and connectivity have enabled a wide range of applications that can harness data collection for better decision making and an improved lifestyle. The Internet of Things (IoT) provides the communication infrastructure that allows devices with sensing and control capabilities to be connected within a home network. Smart home systems are considered one of the prominent applications in IoT, where it is possible to control home devices to achieve a better usage in terms of cost and comfort. However, smart home networks contain a wide range of devices and finding an optimal schedule for their working hours is an NP-hard problem. Hence, rather than using mathematical optimization to find optimal solutions, this paper proposes a modeling and simulation methods in order to provide good decisions and recommendations for devices’ scheduling. Discrete Event System Specification (DEVS) formalism is used to develop a model of a smart home network. The devices are categorized into two groups: monitoring devices and control devices. Monitoring devices include sensors that capture climate, energy, power, performance, and occupant’s behavioral data. Control devices send signals remotely for setting and controlling different devices in the smart home network. The behavior in terms of power usage and cost is simulated under different scenarios and settings. The simulation results show that less energy consumption can be achieved if users adopt a behavior where the schedule of three devices is changed every week. As a result, the proposed method can be utilized to make better decisions in setting devices parameters and evaluating the performance of the smart devices network under different conditions, scenarios, and settings.

Cell-DEVS for Social Phenomena Modeling

Motivated by the need for formal methods as well as supporting tools to model and simulate social systems, we propose cellular discrete-event system specification as a formalism for modeling social systems. We also propose the use of a toolkit that implements the formalism of cellular discrete-event system specifications to implement and visualize models of social systems. We present examples of social system models that are different in sizes, nature, and rules controlling the interactions within those systems. We show that cellular discrete-event system specification with its unique features can successfully deal with the shortcoming of other modeling techniques. In addition, we show that together with its supporting toolkit, cellular discrete-event system specification is suitable for modeling, simulating, implementing, and visualizing social systems.

DEVS-based Modeling Methodology for Cybersecurity Simulations from a Security Perspective

Security administrators of companies and organizations need to come up with proper countermeasures against cyber-attacks considering infrastructures and security policies in their possession. In order to develop and verify such countermeasures, the administrators should be able to reenact both cyber-attacks and defenses. Simulations can be useful for the reenactment by overcoming its limitations including high risk and cost. If the administrators are able to design various scenarios of cyber-attacks and to develop simulation models from their viewpoints, they can simulate desired situations and observe the results more easily. It is challenging to simulate cyber-security issues, because there is lack of theoretical basis for modeling a wide range of the security field as well as pre-defined basic components used to model cyber-attacks. In this paper, we propose a modeling method for cyber-security simulations by developing a basic component and a composite model, called Abstracted Cyber-Security Unit Model (ACSUM) and Abstracted Cyber-security SIMulation model (ACSIM), respectively. The proposed models are based on DEVS(Discrete Event systems Specification) formalism, a modeling theory for discrete event simulations. We develop attack scenarios by sequencing attack behaviors using ACSUMs and then model ACSIMs by combining and abstracting the ACSUMs from a security perspective. The concepts of ACSUM and ACSIM enable the security administrators to simulate numerous cyber-security issues from their viewpoints. As a case study, we model a worm scenario using ACSUM and simulate three types of simulation models based on ACSIM from a different security perspective.

A discrete event model for analysis and verification of time‐constrained business processes

SummaryIn the purpose of analyzing and checking time constraints in business processes, we propose to model and simulate them in the “discrete event system specification” (DEVS) formalism. The proposed model will contain atomic DEVS models representing the activities, supervised by, other DEVS control models, and based on one to one mapping. Hence, guaranteeing a close concordance with the temporal requirements. Thus, the simulation of the model results in outputs about the successful execution regarding to the temporal constraints soundness. Therefore, the modeler will be able to predict unsuitable temporal behavior. Thus, the model responds to the lack of modeling tools that do not offer enough formal specification of time constraints at the earlier phases of design as in, the standard “business process management notation.” The proposed model handles different type of time constraints in business process such as intra‐activities, inter‐activities, and inter‐process time constraints. The proposed model is implemented into JAVADEVS using DEVS‐Suite platform.

Discrete Event Systems Specifications Modelling and Simulation of Wireless Networking Applications

ABSTRACT We discuss the use of formal discrete-event modelling and simulation for networking applications, in particular, for mobile networks and Wireless Sensor Networks (WSN). We show how one can develop discrete-event model libraries based on the DEVS formalism for mobile networks, allowing tracking the users’ upload status in a given area of coverage, while using a non-cooperative algorithm or Coordinated Multipoint (CoMP) synchronisation. We show a DEVS model library for CoMP-based networks, showing how control messaging can be managed among Evolved Node Base stations (eNBs). We build a case study comparing two CoMP approaches: Joint Processing (JP) and Coordinated Scheduling (CS). Finally, we show how DEVS models can be used to model malware propagation in wireless sensor networks based on epidemic theory.

Designing real‐time systems using imprecise discrete‐event system specifications

SummaryReal‐time (RT) systems include hardware and software components interacting in a tight fashion. Although formal methods for RT systems development have advanced, they are sometimes difficult to apply in practical applications, and scalability is compromised as the complexity of the system scales up. Instead, using modeling and simulation (M&S) methods and tools has showed to be useful for verification of practical aspects of RT systems (and having the advantage to be able to including models of the physical environment they interact with). Although several efforts exist in M&S of RT systems, none of them has considered problems of transient overloading in the RT systems specifications. Here, we introduce a new theoretical framework called I‐DEVS (imprecise discrete event systems specification) with the goal of guaranteeing responses to inputs within specified time constraints under such transient overloading conditions. The solution presented here has the advantages of a formal specification and the practicality of an M&S‐based approach. We also discuss how to define hierarchical models running in RT, and we present a set of tools that can be applied to develop RT‐embedded applications, and RT simulations.