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This paper proposes algorithms for supervisor synthesis in discrete event system models with distinguishers. Distinguishers are special components responsible to select an enabled event from a group of related refined events. They are a helpful modelling tool, but their use increases the state space and makes supervisor synthesis more difficult. The paper shows how general algorithms for modular or compositional synthesis can be enhanced by considering the special properties of distinguishers. This gives rise to systematic algorithms that compute least restrictive controllable and nonblocking supervisors, while working with only a part of the distinguisher model. A worked case study of a bottling plant demonstrates the efficacy of the approach.

This paper deals with control of industrial systems which can be depicted by timed event graphs. A methodology and software tools are presented to allow engineers to implement automatically controllers in PLC. Three steps are needed and recalled: the modelling of the system in max plus algebra, the design of the controller and the implementation in a Supervisory Control and Data Acquisition (SCADA) system. An example on a real system is given to illustrate these steps.

Cyber-physical systems have been highly integrated into many contemporary infrastructures. As this integration deepens, the importance of protecting these systems from unauthorized access and data corruption increases. Nowadays, cyber-physical systems are not well protected against network attacks. One solution is to improve the security of a system by encrypting the transmitted data. In this paper, we consider the encryption of supervisors of discrete event systems modeled with deterministic finite-state automata. We propose an encryption framework of supervisory control systems based on the matrix notation of automata. The purpose of using matrix notation is to make it suitable for homomorphic encryption schemes over integers, which are emerging in the cryptography area. We calculate the entropy of the matrix notation and find that as the size of a system increases, it gets smaller and approaches zero. Owing to the low entropy of the matrix notation, we propose an algorithm to enhance its entropy. By applying the entropy-enhancing process, the distribution characteristics of entries in matrices or vectors can be hidden to avoid a brute force attack. Correspondingly, we propose an entropy restoration algorithm to ensure that the control action can be transmitted correctly.

This paper proposes algorithms for supervisor synthesis in discrete event system models with distinguishers. Distinguishers are special components responsible to select an enabled event from a group of related refined events. They are a helpful modelling tool, but their use increases the state space and makes supervisor synthesis more difficult. The paper shows how general algorithms for modular or compositional synthesis can be enhanced by considering the special properties of distinguishers. This gives rise to systematic algorithms that compute least restrictive controllable and nonblocking supervisors, while working with only a part of the distinguisher model. A running example of a manufacturing cell illustrates the approach.

This paper discusses a method to distribute a synthesized supervisory controller for implementation on multiple physical controllers. Dependency structure matrices are used to determine a distribution of a discrete event system. The supervisor is then distributed accordingly, using an existing localization method. Communication delays between the distributed components of a supervisor may affect its behavior, due to changes in the order of events. Therefore, a delay-robustness check is performed and where needed mutex locks are employed to make the distributed supervisor delay-robust. A case study demonstrates the method, and hardware-in-the-loop testing is used to validate the distributed supervisor.

Most research in fault diagnosis of discrete event systems has been focused on permanent failures. However, experience with monitoring of dynamic systems shows that intermittent faults are predominant, and that their diagnosis constitutes one of the most challenging tasks for surveillance activities. Among the main existing approaches to deal with permanent faults, two were widely investigated while considering different settings: the Diagnoser based approach, and the Twin-plant based approach. The latter was developed to cope with some complexity limitations of the former. In the present paper, we propose a twin-plant based approach to deal with diagnosability of intermittent faults. Firstly, we discuss various notions of diagnosability, while considering the occurrence of faults, their recovery, and the identification of the system status. Then, we establish the necessary and sufficient conditions for each notion, and develop on-the-fly algorithms to check these properties. The discussed approach is implemented in a prototype tool that is used to conduct experiments on a railway control benchmark.

Given the non-repeatability, complexity, and unpredictability of unconventional public health emergencies, building accurate models and making effective response decisions based only on traditional prediction–response decision-making methods are difficult. To solve this problem, under the scenario–response paradigm and theories on parallel emergency management and discrete event system (DES), the parallel simulation decision-making framework (PSDF), which includes the methods of abstract modeling, simulation operation, decision-making optimization, and parallel control, is proposed for unconventional public health emergency response processes. Furthermore, with the example of the severe acute respiratory syndrome (SARS) response process, the evolutionary scenarios that include infected patients and diagnostic processes are transformed into simulation processes. Then, the validity and operability of the DES–PSDF method proposed in this paper are verified by the results of a simulation experiment. The results demonstrated that, in the case of insufficient prior knowledge, effective parallel simulation models can be constructed and improved dynamically by multi-stage parallel controlling. Public health system bottlenecks and relevant effective response solutions can also be obtained by iterative simulation and optimizing decisions. To meet the urgent requirements of emergency response, the DES–PSDF method introduces a new response decision-making concept for unconventional public health emergencies.

Fault detection and diagnosis &#x0028 FDD &#x0029 facilitates reliable operation of systems. Various approaches have been proposed for FDD like Analytical redundancy &#x0028 AR &#x0029, Principal component analysis &#x0028 PCA &#x0029, Discrete event system &#x0028 DES &#x0029 model etc., in the literature. Performance of FDD schemes greatly depends on accuracy of the sensors which measure the system parameters. Due to various reasons like faults, communication errors etc., sensors may occasionally miss or report erroneous values of some system parameters to FDD engine, resulting in measurement inconsistency of these parameters. Schemes like AR, PCA etc., have mechanisms to handle measurement inconsistency, however, they are computationally heavy. DES based FDD techniques are widely used because of computational simplicity, but they cannot handle measurement inconsistency efficiently. Existing DES based schemes do not use Measurement inconsistent &#x0028 MI &#x0029 parameters for FDD. These parameters are not permanently unmeasurable or erroneous, so ignoring them may lead to weak diagnosis. To address this issue, we propose a Measurement inconsistent discrete event system &#x0028 MIDES &#x0029 framework, which uses MI parameters for FDD at the instances they are measured by the sensors. Otherwise, when they are unmeasurable or erroneously reported, the MIDES invokes an estimator diagnoser that predicts the state&#x0028 s &#x0029 the system is expected to be in, using the subsequent parameters measured by the other sensors. The efficacy of the proposed method is illustrated using a pump-valve system. In addition, an MIDES based intrusion detection system has been developed for detection of rogue dynamic host configuration protocol &#x0028 DHCP&#x0029 server attack by mapping the attack to a fault in the DES framework.

As smart factories are emerging, the importance of modeling and simulation (M&S) continues to increase in the production system. As a result, various commercial tools and environments are provided for production simulation, and manufacturing companies are also applying them to establish a smart manufacturing system. This is used in various ways, such as optimal layout design, scheduling, and fault diagnosis using the acquired smart manufacturing model. However, these model constructions are generally done through a stand-alone environment in which the work type or user level is not considered. It is necessary to use different environments depending on the user level or to rely on M&S experts. Therefore, this paper eliminates this inefficiency and proposes an integrative user-level customized smart manufacturing M&S environment for all users in the production system. It provides three-phase modeling environments appropriate for the user level, including an automatic model synthesis interface and a production line generator. Using this environment, anyone can easily make capacity and logistic models, and simulate them.

The paper provides a general view on the original logical inference based approach to dealing with discrete event systems as subject to supervisory control theory. The approach proposes a representation of automata-based discrete event system as a positively constructed formula and implementation of the calculus of positively constructed formulas. The stages of a supervisor construction are illustrated with a simplified model of an autonomous underwater vehicle operational modes switching. The supremal controllable sublanguage of the specification and the supervisor are constructed.

This demo presents VirtualCrowd, a simulation platform for crowdsourcing campaigns. The platform allows the design, configuration, step-by-step execution, and analysis of customized tasks, worker profiles, and crowdsourcing strategies. The platform will be demonstrated through a crowd-mapping example in two cities, which will highlight the utility of VirtualCrowd for complex crowdsourcing tasks in real world settings.

For a real-time system (RTS) processing both sporadic and (multiple-period) periodic tasks, this study presents a novel modular modeling framework to describe the parameters of tasks, conforming to the pertinent concepts and techniques of discrete-event systems (DES). A task is represented by an automaton synchronized by the modular models corresponding to its parameters. As a consequence, a DES model depicting the RTS is synchronized by the DES representing these tasks. Based on supervisory control theory, priority-free conditionally-preemptive (PFCP) real-time scheduling is solved by finding all the safe execution sequences. Finally, the PFCP scheduling is illustrated by real-world examples.

Rogue Twin Access Point (AP) is a rogue Wi-Fi hotspot/AP setup by an adversary solely with the purpose of luring Wi-Fi stations (STAs) into connecting to them. An adversary clones the Service Set IDentifier (SSID) [Hotspot Name] as well as the MAC address of the legitimate AP while setting up the rogue twin. When a STA checks for the list of available APs (under presence of rogue twin), it sees only one AP (despite there being two APs with the identical SSID and MAC address). In case the signal strength of the rogue twin is more than the legitimate AP, the STA connects to the rogue twin.In the present study, a Discrete Event System (DES) paradigm based Intrusion Detection System (IDS) for detecting rogue twin which is proposed. It overcomes many drawbacks of existing approaches in tackling rogue twin. A normal DES model corresponding to a frame exchange under normal network conditions along with a failure (attacker) DES model corresponding to a frame exchange under rogue twin network conditions is constructed. Using the knowledge of the normal and attacker DES models, a DES diagnoser is constructed to ascertain whether the frame exchange corresponds to a normal or attack condition. Even if an attacker uses multiple techniques to launch the rogue twin the proposed DES based IDS is capable of identifying all such possible instances. We validate the scheme on a real test bed.

International audience; In this paper, we present a method for discrete event system identification with the aim of fault detection. The method is based on a new model called Deterministic Automaton with Outputs and Conditional Transitions (DAOCT), which is computed from observed fault-free paths, and represents the fault-free system behavior. In practice, a trade-off between size and accuracy of the identified automaton has to be found. In order to obtain compact models, loops are introduced in the model, which implies that sequences that are not observed can be generated by the model leading to an exceeding language. This exceeding language is associated with possible non-detectable faults, and must be reduced in order to use the model for fault detection. We show, in this paper, that the exceeding language generated by the DAOCT is smaller than the exceeding language generated by another model proposed in the literature, reducing, therefore, the number of possible non-detectable faults. We also show that if the identified DAOCT does not have cyclic paths, then the exceeding language is empty, and the model represents all and only all observed fault-free sequences generated by the system. In order to illustrate the results of the paper, a physical system is simulated by using a 3D simulation software controlled by a Programmable Logic Controller (PLC). The main idea is to use a virtual digital system to simulate the fault-free behavior of a physical system, captured by the sequences of input and output signals of the PLC, and then use the method proposed in the paper to obtain the DAOCT model of the plant.

The development of the AI, IoT, and Big Data have to become strongly apply to discrete event strings systems. That are modern developments of the world. Therefore, we have to have an advanced method to develop adaptive applications, especially with MIMO discrete event systems. There is a limit while using a continuous calculation to control systems because the big calculation is an obstacle. So we have to find an optimization method to reduce the number of parameters in the calculation at any time. We could do it by choice the main parameters and except auxiliary parameters. In this paper, we introduce a Football Team Optimization (FTO) method, which is a new method to do optimization problem while control with many parameters system. The application and analysis to compare any method as PSO, traditional PID, which takes out the difference of this algorithm.

Due to the rapid increase in digitalization and networking of systems, especially in industrial environments, the number of cyber-physical systems is increasing and thus the danger of possible attacks on such systems. As demonstrated in several recent examples, a cyber attack on an industrial control system (ICS) can have catastrophic consequences for humans and machines. This is due to the communication networks between programmable logic controllers (PLC), actuators and sensors, which are usually vulnerable to attacks, as well as various processes or devices that are not sufficiently protected. In this paper, two possible attacks on a discrete event system (DES) are introduced, in which a running process, controlled by a PLC, is manipulated without being detected. Furthermore, a detection method for such attacks is presented.

The innovation trends in the area of health and medical treatments seek how to effectively test the devices to be introduced into the human body. This work discusses the different approaches to model the human cardiovascular system. Besides, a modelling proposal, based on hybrid systems (systems of continuous variables combined with discrete event systems), of the cardiovascular system is presented. Its purpose is evaluating implantable medical devices, such as Ventricular Assist Devices (VADs).

Patients’ overcrowding in Emergency Department (ED) is a major problem in medical care worldwide, predominantly due to time and resource constraints. Simulation modeling is an economical approach to solve complex healthcare problems. We employed Discrete Event System Specification-JAVA (DEVS-JAVA) based model to simulate and test changes in emergency service conditions with an overall goal to improve ED patient flow. Initially, we developed a system based on ED data from South Carolina hospitals. Later, we ran simulations on four different case scenarios. 1. Optimum number (no.) of doctors and patients needed to reduce average (avg) time of assignment (avg discharge time = 33 min). 2. Optimum no. of patients to reduce avg discharge time (avg wait time = 150 min). 3. Optimum no. of patients to reduce avg directing time to critical care (avg wait time = 58 min). 4. Optimum no. of patients to reduce avg directing time to another hospital (avg wait time = 93 min). Upon execution of above 4 simulations, 4 patients got discharged utilizing 3 doctors; 5 patients could be discharged from ED to home; 2 patients could be transferred from ED to critical care; 3 patients could be transferred from ED to another hospital. Our results suggest that the generated DEVS-JAVA simulation method seems extremely effective to solve time-dependent healthcare problems.

Background: The probabilistic discrete event systems (PDES) method provides a promising approach to study dynamics of underage drinking using cross-sectional data. However, the utility of this approach is often limited because the constructed PDES model is often non-identifiable. The purpose of the current study is to attempt a new method to solve the model. Methods: A PDES-based model of alcohol use behavior was developed with four progression stages (never-drinkers [ND], light/moderate-drinker [LMD], heavy-drinker [HD], and ex-drinker [XD]) linked with 13 possible transition paths. We tested the proposed model with data for participants aged 12-21 from the 2012 National Survey on Drug Use and Health (NSDUH). The Moore-Penrose (M-P) generalized inverse matrix method was applied to solve the proposed model. Results: Annual transitional probabilities by age groups for the 13 drinking progression pathways were successfully estimated with the M-P generalized inverse matrix approach. Result from our analysis indicates an inverse “J” shape curve characterizing pattern of experimental use of alcohol from adolescence to young adulthood. We also observed a dramatic increase for the initiation of LMD and HD after age 18 and a sharp decline in quitting light and heavy drinking. Conclusion: Our findings are consistent with the developmental perspective regarding the dynamics of underage drinking, demonstrating the utility of the M-P method in obtaining a unique solution for the partially-observed PDES drinking behavior model. The M-P approach we tested in this study will facilitate the use of the PDES approach to examine many health behaviors with the widely available cross-sectional data.

Due to the complexity and randomness of emergency demands, it is difficult to describe and analyze the Emergency Medical Service Systems (EMSS) just by certain modeling. Therefore, a stochastic modeling and simulating method for EMSS optimizing is proposed based on the Discrete Event System theory. With a fictive and stochastic medical emergency scenario, the relevant simulation model is constructed with the FLEXSIM software quickly and explicitly. And by simulating and analyzing, it is easily to discover the bottlenecks and to optimize the EMSS system.

This paper describes the process followed for designing a computational tool to improve the scheduling of surgeries in a regional healthcare institution where the availability of surgeons and medical staff is limited and heavily constrained. The goal is to analyze the characteristics of the system so as to design the structure of the master surgical schedule and select and appropriate set of rules aiming at reducing the waiting time for elective and ambulatory procedures and increasing the use of the rooms. In first place, the characteristics of the demand are studied by collecting and analyzing the information recorded during a two-year time lapse. Then, this information is used as an input to imitate the characteristics of the process through a discrete event system simulation model which can be used to analyze the performance of the system when different strategies are adopted. In particular, easy-to-use rules of thumb, adapted to the simplicity of the studied system are analyzed. For example, offline and online scheduling strategies and combination of these with operatory blocks (defined as a time dedicated exclusively to a given specialty) are studied. Then, upon the basis of the results obtained, a user-friendly computer interface is designed such that the process, that was predominantly carried out by hand, can be automated while improving systems performance and reducing the effort devoted by the personnel in charge.

International audience; Industrial Control Systems (ICS) are integrated in many areas and critical infrastructures from manufacturing systems to energy production and distribution networks. Originally, these systems have been designed to insure the productivity and reliability of a system. Since the beginning of the century, ICS are targeted by hackers that use vulnerabilities in control-command architecture and component to physically damage the system and its environment. These vulnerabilities are induced by introduction of Information Technology (IT) that brings major improvements as communication speed or standardization of architecture. Furthermore, despite these advantages, IT provides incomplete or incompatible solutions from security point of view for ICS. This paper presents an innovative approach for detecting intrusions in ICS based on different works in safety and security fields. Indeed, by coupling the Filter Approach with theory of Intrusion Detection System (IDS), we propose an approach to detect and block orders that could damage the system. Moreover, the notion of distance between states is developed to anticipate potential attacks and distinguish cyberattacks from classical failures. The study is supported by simulation inspired by classical ICS and industrial platforms.

Transaction-based systems, such as Mathworks SimEvents and Stateflow, are the efficient solution for discrete event simulation in the field of mechatronic systems and transportation. Possible analysis of simulation, which can be done by the change of the attributes, results suggests solutions to address desired issues.

A practical problem in automation systems modeling is the choice between a fully hybrid approach and the fluidization of some parts conserving the general discrete event approach. This paper explores the approach based on specific hybrid parts into a discrete event system using a unified Petri nets environment called GHENeSys (General Hierarchical Enhanced Net System), which follows the ISO/IEC 15909 standard and includes extensions such as hierarchy and time concepts. Then, a design method based on GHENeSys Timed Hybrid Petri Net (GTHPN) technique is proposed to model these hybrid parts. GHENeSys subnets are associated with macro-places and help to control combinatorial explosion and has extended arcs to guarantee the GTHPN applicability to practical cases. All resulting models of the approach proposed could also benefit from an easier conversion to PLC programs in IEC 61131 representation. A case study is presented for producing constructive blocks showing the advantages of the current proposition. Un problema práctico en sistemas automatizados es la selección entre el enfoque totalmente híbrido o la fluidización de algunas partes conservando el enfoque general de eventos discretos. Este articulo trata el enfoque basado en partes hibridas en un modelo discreto usando el ambiente unificado de Redes de Petri llamado GHENeSys (Sistema de Red Extendida Jerárquica General), compatible con la norma ISO/IEC 15909 incluyendo los conceptos de jerarquía y tiempo. Por tanto, se propone un método de diseño y una técnica GTHPN (Redes de Petri Temporizadas Hibridas GHENeSys) para modelar estas partes híbridas. Las subredes en macro-lugares controlan la explosión de estados y controlar transiciones mediante arcos extendidos de GHENeSys garantiza la efectividad de GTHPN para casos prácticos. Además, todo modelo resultante permite una fácil conversión a programas de PLCs en lenguajes IEC61131. Se presenta un caso de estudio para producción de bloques de construcción demostrando estas ventajas mencionadas.

This paper presents a modeling method to demonstrate engagement-level military simulation which includes few combat objects, or entities. To this end, the paper, on the basis of the discrete event system specification (DEVS) formalism, centers on two ideas: (1) a combat entity’s model structure at the composition level; and (2) behavioral delineation of the entity’s elementary component. In detail, we classify the combat entity model into platform and weapon models and create six groups of the model categorized by two dimensions: three activities and two abstractions. And the elementary component in the group interprets an engagement scenario as a flow of executable tasks, which are expressed by DEVS semantics. The stated structures and semantics provide intuitive appeal, reducing the effort required to read and understand the model’s behavior. From the combat experiments, we can gain interesting experimental results regarding engagement situations employing underwater weapons and their tactical operations. Finally, we expect that this work will serve an immediate application suited to various engagement situations.

This paper presents an active-learning technique for constructing a fault diagnoser for an unknown finite-state Discrete Event System (DES). The proposed algorithm actively asks some basic queries from an oracle through which the algorithm completes a series of observation tables leading to the construction of the diganoser. The resulting diagnoser is a deterministic-finite-state automaton, which detects and identifies occurred faults by monitoring the observable behaviors of the plant. An illustrative example is provided detailing the steps of the proposed algorithm.

This paper introduces user intervention to control simulation states during the execution of a simulation for military engagements. In an engagement simulation, it covers both a discrete event system and a continuous state system. Thus a system for the engagement simulation can have numerous simulation states, because there are lots of factors to decide states of an engagement that are derived during an execution of the simulation (e. g. detection probability, moving speed, moving path, and so on). It means both a result and progression of simulations are important outputs. Configuration of an engagement simulation scenario and expectation of simulation states, though, is hindered by the number of generate-able states. In order to solve the obstacle, the engagement simulation system should be controllable by user intervention during a simulation execution. This paper is to define objects of user intervention, and to design control processes of defined objects.

A reverse engineering approach to generate a virtual plant model is proposed. The model can be used for programmable logical controller (PLC) simulation. The virtual plant model for the PLC simulation consists of virtual device models and must interact with the input and output signals of a PLC. The behavior of a virtual device model should be the same as that of real device. Conventionally, the discrete event system specifications (DEVS) formalism has been used to represent the behavior of a virtual device model. Modeling using DEVS formalism, however, requires in-depth knowledge of the simulation area, as well as a significant amount of time and effort. One of the key ideas of the proposed methodology is to provide a method to generate a virtual plant model using both log data (time-stamped signal history) and a PLC I/O signal table extracted from the existing production system. The proposed reverse engineering approach provides two major benefits: (1) significant reduction in the time and effort for the construction of a reliable virtual plant model of a current production system, which can be referenced for newly planned production systems, and (2) reduction in the stabilization time of a production system through PLC simulation. The proposed approach was implemented and applied to an automated production line.

Failure Detection and Diagnosis (FDD) using Discrete Event System (DES) framework is used for wide range of applications because of simplicity of both the model and associated algorithms. Initial research was focussed on permanent failures. Many systems exhibit temporary failures in the sense that system recovers to normal condition after failure. Contant et al. extended the event based DES framework, developed for permanent failure by Sampath et al. to handle temporary failures. Zad et al. developed a state based DES framework for permanent failures which has several advantages compared to the event based approach. In this paper, we extend the state based DES framework, developed for permanent failures, to handle temporary failures, maintaining the same order of complexity. The proposed DES framework has several advantages compared to that by Contant et al. namely, capability to detect failures that occur before starting execution of the diagnoser, same diagnoser for both temporary and permanent failures, etc.

Control of a multilevel system is developed for a discrete-event system (DES) structured by an engineering model. In a multilevel system, each subsystem has a set of children at the next-lower level and a unique parent at the next-higher level. A coordinated multilevel DES is defined by the condition that a parent also is involved in the interaction of each tuple of its children. Control synthesis is carried out per subsystem. If the specification language is conditionally decomposable, conditionally controllable, and conditionally normal then there exists a set of supervisors such that the closed-loop system of the multilevel system meets the specification. The complexity gain is considerable. The examples of an MRI scanner and of a vehicle system illustrate the approach.

This paper focuses on modeling of emergency shut-down control system in an off-shore gas platform using petri net. Considering the nature of the safety control system in industries, it can be considered as a discrete event system. In this regard, first the equipments under emergency shutdown system along with the rules that govern how they act are modeled. Then, the local shut down in all unit separately , after that, process shut down which rules the performance of process unit equipment in emergency situation, in the next step, high level emergency shutdown(level ) and the platform emergency shut down as a hierarchical modeling system are modeled . Finally by combining the models, the final structure implementable on programmable logical controller was modeled by Snoopy software. The full model contains details of all units and criteria governing them, we suffice to mention excerpts of the entire designed model.

With the power system becoming more and more complex it is nearly impossible to monitor and diagnose the failures manually. In this paper power system failure diagnosis is done using the discrete event system approach. Model based diagnosis in discrete event systems (DES) has gone through many developments. We introduce a new framework of Observer based Discrete Event Systems (ODES) to include event outputs in addition to state outputs. It is shown that ODES can make a system diagnosable even though the system is not diagnosable when considering only state outputs and using the conventional DES approach. Besides, ODES while suppressing the unobservable failure states can reduce the severity of state explosion problem inherent in the DES application to large systems.

Discrete Event System Specification (DEVS) is a set theoretic formalism developed for specifying discrete event systems. DEVS features the specifications of hierarchical system and sequential event. Mobile application system is one of the typical systems that have hierarchical structure and sequential processes. However, there has been no attempt to express the mobile application system as DEVS formalism. This paper describes the design and development of mobile application behavior using DEVS model and we have classified the types of the mobile app behaviors as: temporal behavior, non-temporal behavior. Each behavior is stated as an atomic model and the mobile app events are represented as a coupled model. By using the DEVS formalism, not only we can simulate most of the mobile application events using real device; but also we expect that this work will serve as an effective tool for usability test.

A constrained optimization framework of an autonomous urban transport system, associated with reduced rates, is presented. A decentralized management is considered where prior seat reservation is not a prerequisite for the system functioning. Well-adapted vehicle itineraries based on the current demand and vehicle state are constructed. The event-driven system dynamics characterizing the non-deterministic features of the corresponding complex mathematical problem, encourage for a discrete event system approach. The implied stressing needs of a comprehensive study, will be achieved by intense simulations. Various strategies, related to real time controls and system dimensioning as well, are studied. A methodology appraising the system performance is introduced where the resulting system behaviour is evaluated in terms of client waiting time, detours, vehicle occupancy, travel times etc. Moreover, optimal parameter tuning is discussed underlying the importance of reasonable trade-offs for achieving the desired performance. Thus, involving optimisation, operational research methods and simulation techniques a significantly efficacious well-operating system can be achieved, providing the best suited configuration for any demand level and geometry. Utilising previously wasted vehicle capacity may reduce costs for both vehicles and clients while forms an ongoing attempt to control extended traffic congestion, air pollution, energy consumption etc.

Cascading outages in power system is a major concern in the industry and protection system failures contribute to it. With the increasing complexity of power system, manual monitoring and diagnosis is impossible. Failure diagnosis using discrete event systems has been an active area of interest in the last three decades and has produced creditable results. In this paper, power system protection system is modeled for failure diagnosis using a modified form of the discrete event system model. In particular, a framework using observations in modeling the component is developed for power system protection failure diagnosis. This modeling approach does away with the need to include unobservable events and is capable of predicting the diagnosability during component modeling itself. Simple conditions for diagnosability are stated for the modified DES. A diagnoser is developed for a power system protection example using the modified DES. Further, the robustness of the diagnoser is demonstrated.

An automated warehouse system has two main components: an automated storage and retrieval subsystem consisting of a number of aisles, each one served by a crane, and a picking area which is formed by bays where stock units coming from the aisles are partially emptied by human operators. These two components are connected via an interface area consisting of carousels, conveyors, and buffers. This area is usually modeled as a discrete event system, while the overall system performance depends also on continuous time phenomena. Part I presents a hybrid model based on a new Petri net formalism that merges the concepts of Hybrid Petri Nets and Colored Petri Nets to obtain modular and compact models for these systems. An example is discussed in detail to motivate the introduction of a new formalism. A control oriented simulation tool is also presented. Part II will focus on the application of this formalism to automated warehouse systems analysis and performance evaluation. Finally, a real case study is considered to show the effectiveness of the approach.

In 2013 the Editor of Journal of Vibration and Control and SAGE became aware of a peer review ring involving assumed and fabricated identities that appeared to centre around Peter Chen at National Pingtung University of Education, Taiwan (NPUE). SAGE and the Editor then began a complex investigation into the case during the rest of 2013 and 2014. Following an unsatisfactory response from Peter Chen, NPUE was notified. NPUE were serious in addressing the Journal and SAGE’s concerns. NPUE confirmed that the institution was investigating Peter Chen. SAGE subsequently uncovered a citation ring involving the above mentioned author and others. We regret that individual authors have compromised the academic record by perverting the peer review process and apologise to readers. On uncovering problems with peer review and citation SAGE immediately put steps in place to avoid similar vulnerability of the Journal to exploitation in the future. More information may be found at www.sagepub.co.uk/JVC_Statement_2014 . The Journal and SAGE understand from NPUE that Peter Chen has resigned his post at NPUE. The following articles are retracted because after thorough investigation evidence points towards them having at least one author or being reviewed by at least one reviewer who has been implicated in the peer review ring and/or citation ring. All authors have had an opportunity to respond to the allegations and proposed actions. OnlineFirst articles (these articles will not be published in an issue) Chen CY, Chen T-H, Chen Y-H, Yu S-E and Chung P-Y (2013) Information technology system modeling an integrated C-TAM-TPB model to the validation of ocean tidal analyses Journal of Vibration and Control Epub ahead of print 7 May 2013. doi: 10.1177/1077546312472924 Chang R-F, Chen CY, Su F-P and Lin H-C (2013) A two-step approach for broadband digital signal processing technique Journal of Vibration and Control Epub ahead of print 26 April 2013. doi: 10.1177/1077546312472925 Chen TH, Chang CJ, Yu SE, Chung PY and Liu C-K (2013) Nonlinear information analysis and system management technique: the influence of design experience and control complexity Journal of Vibration and Control Epub ahead of print 12 April 2013. doi: 10.1177/1077546312473321 Chen CY, Shih BY, Chen YH, Yu SE and Liu YC (2013) The exploration of a 3T flow model using vibrating NXT: II. Model validation Journal of Vibration and Control Epub ahead of print 10 April 2013. doi: 10.1177/1077546312470481 Chen CY, Shih BY, Chen YH, Yu SE and Liu YC (2013) The exploration of 3T flow model using vibrating NXT: I. model formulation Journal of Vibration and Control Epub ahead of print 6 February 2013. doi: 10.1177/1077546312467360 Lin M-L and Chen C-W (2013) Stability analysis of fuzzy-based NN modeling for ecosystems using fuzzy Lyapunov methods Journal of Vibration and Control Epub ahead of print 6 February 2013. doi: 10.1177/1077546312466687 Chen CY, Chen TH, Chen YH and Chiu J (2012) A multi-stage method for deterministic-statistical analysis: a mathematical case and measurement studies Journal of Vibration and Control Epub ahead of print 20 December 2012. doi: 10.1177/1077546312466579 Shih BY, Lin MC and Chen CY (2012) Autonomous navigation system for radiofrequency identification mobile robot e-book reader Journal of Vibration and Control Epub ahead of print 13 December 2012. doi: 10.1177/1077546312466578 Chang RF, Chen CY, Su FP, Lin HC and Lu C-K (2012) Multiphase SUMO robot based on an agile modeling-driven process for a small mobile robot Journal of Vibration and Control Epub ahead of print 13 December 2012. doi: 10.1177/1077546312464993 Shih B-Y, Lin Y-K, Cheng M-H, Chen C-Y and Chiu C-P (2012) The development of an application program interactive game-based information system Journal of Vibration and Control Epub ahead of print 12 December 2012. doi: 10.1177/1077546312464682 Chen C-Y, Chang C-J and Lin C-H (2012) On dynamic access control in web 2.0 and cloud interactive information hub: technologies Journal of Vibration and Control Epub ahead of print 12 December 2012. doi: 10.1177/1077546312464992 Shin BY, Chen CY and Hsu KH (2012) Robot cross platform system using innovative interactive theory and selection algorithms for Android application Journal of Vibration and Control Epub ahead of print 13 November 2012. doi: 10.1177/1077546312463757 Articles published in an issue Chen C-W (2014) Applications of neural-network-based fuzzy logic control to a nonlinear time-delay chaotic system Journal of Vibration and Control 20 (4): 589-605. Epub ahead of print 5 November 2012. doi: 10.1177/1077546312461370 Chen C-W (2014) A review of intelligent algorithm approaches and neural-fuzzy stability criteria for time-delay tension leg platform systems Journal of Vibration and Control 20 (4): 561-575. Epub ahead of print 5 November 2012. doi: 10.1177/1077546312463759 Chen C-Y, Chang C-J and Lin C-H (2014) On dynamic access control in web 2.0 and cloud interactive information hub: trends and theories Journal of Vibration and Control 20 (4): 548-560. Epub ahead of print 5 November 2012. doi: 10.1177/1077546312463762 Lin M-L and Chen C-W (2014) Stability conditions for ecosystem modeling using the fuzzy Lyapunov method Journal of Vibration and Control 20 (2): 290-302. Epub ahead of print 23 October 2012. doi: 10.1177/1077546312451301 Chen C-H, Kuo C-M, Hsieh S-H and Chen C-Y (2014) Highly efficient very-large-scale integration (VLSI) implementation of probabilistic neural network image interpolator Journal of Vibration and Control 20 (2): 218-224. Epub ahead of print 22 October 2012. doi: 10.1177/1077546312458822 Chen C-Y (2014) Wave vibration and simulation in dissipative media described by irregular boundary surfaces: a mathematical formulation Journal of Vibration and Control 20 (2): 191-203. Epub ahead of print 22 October 2012. doi: 10.1177/1077546312464258 Chen C-H, Yao T-K, Dai J-H and Chen C-Y (2014) A pipelined multiprocessor system- on-a-chip (SoC) design methodology for streaming signal processing Journal of Vibration and Control 20 (2): 163-178. Epub ahead of print 16 October 2012. doi: 10.1177/1077546312458821 Lin M-L and Chen C-W (2014) Fuzzy neural modeling for n-degree ecosystems using the linear matrix inequality approach Journal of Vibration and Control 20 (1): 82-93. Epub ahead of print 8 October 2012. doi: 10.1177/1077546312458533 Chen C-H, Wu W-X and Chen C-Y (2013) Ant-inspired collective problem-solving systems Journal of Vibration and Control 19 (16): 2481-2490. Epub ahead of print 18 September 2012. doi: 10.1177/1077546312456231 Chen C-H, Yao T-K, Kuo C-M and Chen C-Y (2013) Evolutionary design of constructive multilayer feedforward neural network Journal of Vibration and Control 19 (16): 2413-2420. Epub ahead of print 12 September 2012. doi: 10.1177/1077546312456726 Chen C-W (2013) Applications of the fuzzy-neural Lyapunov criterion to multiple time-delay systems Journal of Vibration and Control 19 (13): 2054-2067. Epub ahead of print 16 August 2012. doi: 10.1177/1077546312451034 Chung P-Y, Chen Y-H, Walter L and Chen C-Y (2013) Influence and dynamics of a mobile robot control on mechanical components Journal of Vibration and Control 19 (13): 1923-1935. Epub ahead of print 20 July 2012. doi: 10.1177/1077546312452184 Chen C-W (2013) Neural network-based fuzzy logic parallel distributed compensation controller for structural system Journal of Vibration and Control 19 (11): 1709-1727. Epub ahead of print 22 June 2012. doi: 10.1177/1077546312442233 Chen C-W, Yeh K, Yang H-C, Liu KFR and Liu C-C (2013) A critical review of structural system control by the large-scaled neural network linear-deferential-inclusion-based criterion Journal of Vibration and Control 19 (11): 1658-1673. Epub ahead of print 18 June 2012. doi: 10.1177/1077546312443377 Chen C-H, Kuo C-M, Chen C-Y and Dai J-H (2013) The design and synthesis using hierarchical robotic discrete-event modeling Journal of Vibration and Control 19 (11): 1603-1613. Epub ahead of print 27 June 2012. doi: 10.1177/1077546312449645 Chang CJ, Chen CY and Chou I-T (2013) The design of information and communication technologies: telecom MOD strength machines Journal of Vibration and Control 19 (10): 1499-1513. Epub ahead of print 27 June 2012. doi: 10.1177/1077546312449644 Shih B-Y, Chen C-Y, Li K-H, Wu T-Y, Chen G-Y (2013) A novel NXT control method for implementing force sensing and recycling in a training robot Journal of Vibration and Control 19 (10): 1443-1459. Epub ahead of print 1 June 2012. doi: 10.1177/1077546312446361 Chen C-W, Chen P-C and Chiang W-L (2013) Modified intelligent genetic algorithm-based adaptive neural network control for uncertain structural systems Journal of Vibration and Control 19 (9): 1333-1347. Epub ahead of print 31 May 2012. doi: 10.1177/1077546312442232 Chen C-Y, Shih B-Y, Shih C-H and Wang L-H (2013) Enhancing robust and stability control of a humanoid biped robot: system identification approach. Journal of Vibration and Control 19 (8): 1199-1207. Epub ahead of print 26 April 2012. doi: 10.1177/1077546312442947 Chang C-J, Chen C-Y and Huang C-W (2013) Applications for medical recovery using wireless control of a bluetooth ball with a hybrid G-sensor and human-computer interface technology Journal of Vibration and Control 19 (8): 1139-1151. Epub ahead of print 24 April 2012. doi: 10.1177/1077546312442948 Hsu W-K, Chiou D-J, Chen C-W, Liu M-Y, Chiang W-L and Huang P-C (2013) Sensitivity of initial damage detection for steel structures using the Hilbert-Huang transform method Journal of Vibration and Control 19 (6): 857-878. Epub ahead of print 29 February 2012. doi: 10.1177/1077546311434794 Chen C-Y, Shih B-Y, Shih C-H and Wang L-H (2013) Human–machine interface for the motion control of humanoid biped robots using a graphical user interface Motion Editor Journal of Vibration and Control 19 (6): 814-820. Epub ahead of print 23 February 2012. doi: 10.1177/1077546312437804 Chen C-Y (2013) Internal wave transport, nonlinear manifestation, and mixing in a stratified shear layer - technical briefs Journal of Vibration and Control 19 (3): 429-438. Epub ahead of print 18 January 2012. doi: 10.1177/1077546311429337 Chen C-W (2013) Delay independent criterion for multiple time-delay systems and its application in building structure control systems Journal of Vibration and Control 19 (3): 395-414. Epub ahead of print 17 January 2012. doi: 10.1177/1077546311429341 Chen C-Y, Shih B-Y, Shih C-H and Wang L-H (2013) Design, modeling and stability control for an actuated dynamic walking planar bipedal robot Journal of Vibration and Control 19 (3): 376-384. Epub ahead of print 17 January 2012. doi: 10.1177/1077546311429476 Liu K-C, Liu Y-W, Chen C-Y and Huang W-C (2013) Nonlinear vibration of structural deterioration in reinforced concrete columns: experimental and theoretical investigation Journal of Vibration and Control 19 (3): 323-335. Epub ahead of print 17 January 2012. doi: 10.1177/1077546311429477 Chen C-Y, Shih B-Y and Ma J-m (2013) Development for low-cost and cross-platform robot control environment Journal of Vibration and Control 19 (2): 228-233. Epub ahead of print 11 January 2012. doi: 10.1177/1077546311430107 Shih B-Y, Chang H and Chen C-Y (2013) Path planning for autonomous robots – a comprehensive analysis by a greedy algorithm Journal of Vibration and Control 19 (1): 130-142. Epub ahead of print 17 January 2012. doi: 10.1177/1077546311429841 Liu T-Y, Chiang W-L, Chen C-W, Hsu W-K, Lin C-W, Chiou D-J and Huang P-C (2012) Structural system identification for vibration bridges using the Hilbert–Huang transform Journal of Vibration and Control 18 (13): 1939-1956. Epub ahead of print 14 December 2011. doi: 10.1177/1077546311428347 Chen C-W (2012) Applications of the fuzzy Lyapunov linear matrix inequality criterion to a chaotic structural system Journal of Vibration and Control 18 (13): 1925-1938. Epub ahead of print 14 December 2011. doi: 10.1177/1077546311428346 Chen C-W (2012) Applications of linear differential inclusion-based criterion to a nonlinear chaotic system: a critical review Journal of Vibration and Control 18 (12): 1886-1899. Epub ahead of print 14 December 2011. doi: 10.1177/1077546311428345 Shih B-Y, Chen C-Y and Chou W (2012) An enhanced obstacle avoidance and path correction mechanism for an autonomous intelligent robot with multiple sensors Journal of Vibration and Control 18 (12): 1855-1864. Epub ahead of print 14 December 2011. doi: 10.1177/1077546311426734 Chen C-W, Yeh K, Liu KFR and Lin M-L (2012) Applications of fuzzy control to nonlinear time-delay systems using the linear matrix inequality fuzzy Lyapunov method Journal of Vibration and Control 18 (10): 1561-1574. Epub ahead of print 18 October 2011. doi: 10.1177/1077546311410765 Chen C-Y (2012) A critical review of internal wave dynamics. Part 2 – Laboratory experiments and theoretical physics Journal of Vibration and Control 18 (7): 983-1008. Epub ahead of print 21 September 2011. doi: 10.1177/1077546310397561 Chen C-Y and Huang P-H (2012) Review of an autonomous humanoid robot and its mechanical control Journal of Vibration and Control 18 (7): 973-982. Epub ahead of print 21 September 2011. doi: 10.1177/1077546310395974 Shih B-Y, Chen C-Y, Chang H and Ma J-m (2012) Dynamics and control for robotic manipulators using a greedy algorithm approach Journal of Vibration and Control 18 (6): 859-866. Epub ahead of print 25 August 2011. doi: 10.1177/1077546311407649 Yeh K, Chen C-W, Lo DC and Liu KFR (2012) Neural-network fuzzy control for chaotic tuned mass damper systems with time delays Journal of Vibration and Control 18 (6): 785-795. Epub ahead of print 15 August 2011. doi: 10.1177/1077546311407538 Chen C-Y, Shih B-Y, Shih C-H and Chou W-C (2012) The development of autonomous low-cost biped mobile surveillance robot by intelligent bricks Journal of Vibration and Control 18 (5): 577-586. Epub ahead of print 21 April 2011. doi: 10.1177/1077546310371349 Chen C-Y (2012) A critical review of internal wave dynamics. Part 1 – Remote sensing and in-situ observations Journal of Vibration and Control 18 (3): 417-436. Epub ahead of print 13 July 2011. doi: 10.1177/1077546310395971 Tseng C-P, Chen C-W and Liu KFR (2012) Risk control allocation model for pressure vessels and piping project Journal of Vibration and Control 18 (3): 385-394. Epub ahead of print 13 July 2011. doi: 10.1177/1077546311403182 Lin M-L and Chen C-W (2011) Stability analysis of community and ecosystem hierarchies using the Lyapunov method Journal of Vibration and Control 17 (13): 1930-1937. Epub ahead of print 9 December 2010. doi: 10.1177/1077546310385737 Chen C-Y, Shih B-Y, Chou W-C, Li Y-J and Chen Y-H (2011) Obstacle avoidance design for a humanoid intelligent robot with ultrasonic sensors Journal of Vibration and Control 17 (12): 1798-1804. Epub ahead of print 26 November 2010. doi: 10.1177/1077546310381101 Chen C-W (2011) Fuzzy control of interconnected structural systems using the fuzzy Lyapunov method Journal of Vibration and Control 17 (11): 1693-1702. Epub ahead of print 23 November 2010. doi: 10.1177/1077546310379625 Shih B-Y, Chen C-Y and Chou W-C (2011) Obstacle avoidance using a path correction method for autonomous control of a biped intelligent robot Journal of Vibration and Control 17 (10): 1567-1573. Epub ahead of print 22 November 2010. doi: 10.1177/1077546310372004 Tang J-P, Chiou D-J, Chen C-W, Chiang W-L, Hsu W-K, Chen C-Y and Liu T-Y (2011) A case study of damage detection in benchmark buildings using a Hilbert-Huang Transform-based method Journal of Vibration and Control 17 (4): 623-636. Epub ahead of print 8 November 2010. doi: 10.1177/1077546309360053 Liu TY, Chiang WL, Chen CW, Hsu WK, Lu LC and Chu TJ (2011) Identification and monitoring of bridge health from ambient vibration data Journal of Vibration and Control 17 (4): 589-603. Epub ahead of print 12 November 2010. doi: 10.1177/1077546309360049 Lin JW, Huang CW, Shih CH and Chen CY (2011) Fuzzy Lyapunov Stability Analysis and NN Modeling for Tension Leg Platform Systems Journal of Vibration and Control 17 (1): 151-158. Epub ahead of print 25 August 2010. doi: 10.1177/1077546309350477 Lee WI, Chen CY, Kuo HM and Sui YC (2010) The Development of Half-circle Fuzzy Numbers and Application in Fuzzy Control Journal of Vibration and Control 16 (13): 1977-1987. Epub ahead of print 22 April 2010. doi: 10.1177/1077546309349849

Protection system failures are recognized as contributing to cascading outages in power system. With the power system becoming more and more complex it is nearly impossible to monitor and diagnose the failures manually. In this paper power system failure diagnosis is done using the discrete event system approach. Model based diagnosis in discrete event systems has gone through a lot of developments. With the advancements in sensor networks and monitoring systems, outputs related to each event are available. A modified DES modeling framework using the event based outputs is developed for power system failure diagnosis. A diagnoser is developed using this model for failure diagnosis. Robust diagnosis is considered and minimal bases diagnosers are identified.

Temporary hoist planning is a key factor for successful project completion in a high-rise building construction. Inadequate plans for hoists in the early stages of a project can cause problems such as failing to hoist resources as required or leaving hoists idle. There are two existing approaches, simple formulas and simulation techniques, for planning temporary hoists. However, simple formulas cannot treat hoist arrangements consisting of different kinds of hoists, while the simulation technique is both time-consuming and tedious when there are many alternatives. In this study, a discrete-event simulation model incorporating genetic algorithms is proposed to support hoist planners while preparing optimal plans with minimal time and effort for high-rise building construction. To verify the applicability of the proposed model, it was applied to a real project and gave better results than a previous approach to temporary hoist planning.

DEVS(Discrete Event Systems Specification) is a set theoretic formalism developed for specifying discrete event system. For execution of DEVS, we need an execution environment, which consists of simulation engine and models interpreted by the simulation engine. Common existing environments use hierarchical scheduling algorithm for DEVS execution. This hierarchical scheduling is a proper algorithm for DEVS execution because of hierarchical and modular characteristics. But this algorithm has overheads owing to message passing and time management. To overcome these overheads, we apply event-oriented simulation to DEVS execution and we remove hierarchical overheads. In eventoriented simulation, the scheduling of model execution is performed by events and event list. We propose three event-oriented execution environments for DEVS and experiment about the performance of our proposed environments in comparison with the existing execution environment using the hierarchical scheduling. The experimental results show our environments works better than existing environment using the hierarchical scheduling.

The modern naval air defense of a fleet is a critical task dictating the equipment, the operation, and the management of the fleet. Military modelers consider that an improved weapon system in naval air defense (i.e. the AEGIS system) is the most critical enabler of defense at the engagement level. However, at the mission execution level, naval air defense is a cooperative endeavor of humans and weapon systems. The weapon system and the command and control (C2) structure of a fleet engage in the situation through human reporting-in and commands, as well as weapon deployments. Hence, this paper models the combination of the human and the weapon systems in naval air defense by covering the C2 hierarchy of the fleet, as well as the weapon systems of warships. After developing this mission-level model, we perform battle experiments with varying parameters in the human and weapon aspects. These battle experiments inform us of the impact of the changes in the human and the weapon systems. For example, the speed of incoming missiles is a critical parameter for a fleet’s survival; yet the decision-making speed is another outstanding parameter, which illustrates that there is more to improve than the weapon system when considering the mission level. This modeling and these experiments provide an example, suggesting a method of combining the human C2 and the weapon systems at the mission level in the military domain.

In this paper, we study opacity-enforcing supervisory control of discrete event systems. We consider the case that the secrete behavior of the system is specified by multiple secret languages, and synthesize a maximally permissive supervisor that enforces opacity for all secret languages. We prove that, under a certain assumption on observable and uncontrollable events, a maximally permissive opacity-enforcing supervisor can be synthesized in a modular fashion.

This paper presents a new challenging modelling approach to support different heuristics to tackle the pallet loading problem (PLP). A discrete event system model to tackle the PLP is specified using the coloured Petri net formalism in order to integrate the model with the industrial context in which the PLP must be solved. New events can be formalised in the model to implement different heuristics to consider the upstream (production) and downstream (transport) influence of the palletising activity in the logistic flow. A state space analysis is performed to evaluate the different solutions to fit the maximum number of boxes on a rectangular pallet, supporting the inherent box diversity (heterogeneous palletising problems) of present production and distribution logistic systems. The heuristics implemented show that acceptable occupancy results can be obtained without requiring the exhaustive evaluation of the different feasible combination. The results demonstrate that it outperforms other approaches whi...

Advanced function of the computer-based river traffic management system should automatically predict and prevent possible conflict and deadlock states between vessels by using adequate control policy (supervisor). This paper proposes a formal method for calculating maximally permissive deadlock prevention supervisor. To model the river system, the authors use a class of Petri net suitable for describing multiple re-entrant flowlines with disjoint sets of resources, jobs and control places, and matrix-based formal method to analyze the system. By using matrix algebra, the structural characteristics of the Petri net (circular waits, P-invariants, critical siphons and subsystem, key resource) have been analyzed and the steps for supervisor design proposed. The first and the second level deadlocks can be avoided by maintaining the number of tokens in the critical subsystems and ensuring that the key resource would not be the last available resource in the system. The derived supervisor has been verified by a computer simulation using MATLAB environment. KEYWORDS: traffic management system, deadlock avoidance, discrete event system, Petri net

This paper aims at defining a software architecture that allows managing an adaptive unfolding of an interactive application such as a game. This architecture basis comes from the one of complex discrete event system control. This paper begins by introducing the general software architecture for games underlying the two main approaches (scenario oriented and emergent). Then the specificities of games are described. It comes from the difficulty to allow the player to have significant impact on the game unfolding without changing the plot structure define a posteriori. Finally an example of a game is given in order to validate a multi-level architecture.