Discrete event dynamic modeling and analysis of the democratic progress in a society controlled by networked agents

2021 ◽  
pp. 1-1
Author(s):  
Seong-Jin Park ◽  
Kwang-Hyun Cho
Keyword(s):  
Dynamic Modeling ◽  
Discrete Event ◽  
Modeling And Analysis ◽  
Event Dynamic

Object-Oriented Petri Net Modeling and Analysis of China Railway Container Freight Yard Logistic System

2011 ◽  
Vol 467-469 ◽  
pp. 990-995
Author(s):  
Li Wang ◽  
Xiao Ning Zhu ◽  
Zheng Yu Xie
Keyword(s):  
Dynamic System ◽  
Petri Net ◽  
Discrete Event ◽  
Object Oriented ◽  
Operation Time ◽  
Modeling And Analysis ◽  
China Railway ◽  
Event Dynamic ◽  
Container Freight ◽  
High Coordination

The railway container freight yard logistic system is a typical discrete event dynamic system (DEDS) and has the feature of high randomness, low flexibility, uncertainty of operation time and high coordination demand of facilities. Object-oriented petri net (OPN) inherits the petri net (PN) advantages for efficiently describing the asynchronism, concurrency, distributivity, parallel DEDS and overcomes the disadvantages when faces complex discrete element dynamic system. We choose object-oriented petri net to model and analyze China railway container freight yard logistic system and get the object OPN model and communication relation net.

Hybrid adaptive Petri nets: a conceptual framework for partial fluidization of Petri nets

1970 ◽  
pp. 50
Author(s):  
E. Fraca ◽  
J. Júlvez ◽  
M. Silva
Keyword(s):  
Petri Nets ◽  
Petri Net ◽  
Dynamic Systems ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Modeling And Analysis ◽  
Analysis Techniques ◽  
High Transition ◽  
Large Systems ◽  
Event Dynamic

Petri nets (PNs) constitute a well known family of formalisms for the modeling and analysis ofDiscrete Event Dynamic Systems (DEDS). As most formalisms for discrete event systems, PNssuffer from the state explosion problem, which renders enumerative analysis techniquesunfeasible for large systems. A technique to overcome the problem is to relax integralitycontraints of the discrete PN model, leading to continuous PN. This relaxation highly reducesthe complexity of analysis techniques but may not preserve important properties of theoriginal PN system such as deadlock‐freeness, liveness, reversibility, etc. This work focuses onHybrid Adaptive Petri nets (HAPNs), a Petri net based formalism in which the firing oftransitions is partially relaxed. The transitions of a HAPN can behave in two different modes:continuous mode for high transition workload, and discrete in other case. This way, a HAPN isable to adapt its behaviour to the net workload, it offers the possibility to represent morefaithfully the discrete model and use efficient analysis techniques by behaving as continuouswhen the load is high. Reachability space and the deadlock‐freeness property of hybridadaptive nets is studied in this work.

Dynamic Modeling and Analysis of an Axially Moving and Spinning Rayleigh Beam Based on a Time-varying Element

2021 ◽  
Author(s):  
Shuai Yang ◽  
ajun Hu ◽  
Guidong Mo ◽  
Xingwang Zhang ◽  
Junjie Qin ◽  
...  
Keyword(s):  
Dynamic Modeling ◽  
Time Varying ◽  
Modeling And Analysis ◽  
Rayleigh Beam ◽  
Axially Moving

scholarly journals Dynamic Modeling and Analysis of 5-PSS/UPU Parallel Mechanism with Elastically Active Branched Chains

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Yanbiao Li ◽  
Hang Zheng ◽  
Bo Chen ◽  
Peng Sun ◽  
Zesheng Wang ◽  
...  
Keyword(s):  
Dynamic Modeling ◽  
Parallel Mechanism ◽  
Modeling And Analysis ◽  
Branched Chains

scholarly journals Petri Net-Based Semi-Compiled Code Generation for Programmable Logic Controllers

2021 ◽  
Vol 11 (15) ◽  
pp. 7161
Author(s):  
Igor Azkarate ◽  
Mikel Ayani ◽  
Juan Carlos Mugarza ◽  
Luka Eciolaza
Keyword(s):  
Code Generation ◽  
Resource Sharing ◽  
Discrete Event ◽  
Transition Function ◽  
Discrete Event Dynamic Systems ◽  
Programmable Logic ◽  
External Software ◽  
Implementation Methodology ◽  
Event Dynamic ◽  
Step Transition

Industrial discrete event dynamic systems (DEDSs) are commonly modeled by means of Petri nets (PNs). PNs have the capability to model behaviors such as concurrency, synchronization, and resource sharing, compared to a step transition function chart or GRAphe Fonctionnel de Commande Etape Transition (GRAFCET) which is a particular case of a PN. However, there is not an effective systematic way to implement a PN in a programmable logic controller (PLC), and so the implementation of such a controller outside a PLC in some external software that will communicate with the PLC is very common. There have been some attempts to implement PNs within a PLC, but they are dependent on how the logic of places and transitions is programmed for each application. This work proposes a novel application-independent and platform-independent PN implementation methodology. This methodology is a systematic way to implement a PN controller within industrial PLCs. A great portion of the code will be validated automatically prior to PLC implementation. Net structure and marking evolution will be checked on the basis of PN model structural analysis, and only net interpretation will be manually coded and error-prone. Thus, this methodology represents a systematic and semi-compiled PN implementation method. A use case supported by a digital twin (DT) is shown where the automated solution required by a manufacturing system is carried out and executed in two different devices for portability testing, and the scan cycle periods are compared for both approaches.

scholarly journals Simulation modeling and analysis of primary health center operations

SIMULATION ◽  
2021 ◽  
pp. 003754972110309
Author(s):  
Mohd Shoaib ◽  
Varun Ramamohan
Keyword(s):  
Resource Utilization ◽  
Waiting Times ◽  
Discrete Event ◽  
Simulation Models ◽  
Modeling And Analysis ◽  
Healthcare Facilities ◽  
Event Simulation ◽  
Analytical Approximations ◽  
Primary Health ◽  
Generic Modeling

We present discrete-event simulation models of the operations of primary health centers (PHCs) in the Indian context. Our PHC simulation models incorporate four types of patients seeking medical care: outpatients, inpatients, childbirth cases, and patients seeking antenatal care. A generic modeling approach was adopted to develop simulation models of PHC operations. This involved developing an archetype PHC simulation, which was then adapted to represent two other PHC configurations, differing in numbers of resources and types of services provided, encountered during PHC visits. A model representing a benchmark configuration conforming to government-mandated operational guidelines, with demand estimated from disease burden data and service times closer to international estimates (higher than observed), was also developed. Simulation outcomes for the three observed configurations indicate negligible patient waiting times and low resource utilization values at observed patient demand estimates. However, simulation outcomes for the benchmark configuration indicated significantly higher resource utilization. Simulation experiments to evaluate the effect of potential changes in operational patterns on reducing the utilization of stressed resources for the benchmark case were performed. Our analysis also motivated the development of simple analytical approximations of the average utilization of a server in a queueing system with characteristics similar to the PHC doctor/patient system. Our study represents the first step in an ongoing effort to establish the computational infrastructure required to analyze public health operations in India and can provide researchers in other settings with hierarchical health systems, a template for the development of simulation models of their primary healthcare facilities.

scholarly journals Control of Discrete Event Systems by Means of Discrete Optimization and Disjunctive Colored PNs: Application to Manufacturing Facilities

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Juan-Ignacio Latorre-Biel ◽  
Emilio Jiménez-Macías ◽  
Mercedes Pérez de la Parte ◽  
Julio Blanco-Fernández ◽  
Eduardo Martínez-Cámara
Keyword(s):  
Discrete Event ◽  
Optimal Solution ◽  
Solution Space ◽  
Discrete Systems ◽  
Discrete Control ◽  
Classic Approach ◽  
Event Dynamic ◽  
Time Required ◽  
Computational Resources ◽  
Control Methodology

Artificial intelligence methodologies, as the core of discrete control and decision support systems, have been extensively applied in the industrial production sector. The resulting tools produce excellent results in certain cases; however, the NP-hard nature of many discrete control or decision making problems in the manufacturing area may require unaffordable computational resources, constrained by the limited available time required to obtain a solution. With the purpose of improving the efficiency of a control methodology for discrete systems, based on a simulation-based optimization and the Petri net (PN) model of the real discrete event dynamic system (DEDS), this paper presents a strategy, where a transformation applied to the model allows removing the redundant information to obtain a smaller model containing the same useful information. As a result, faster discrete optimizations can be implemented. This methodology is based on the use of a formalism belonging to the paradigm of the PN for describing DEDS, the disjunctive colored PN. Furthermore, the metaheuristic of genetic algorithms is applied to the search of the best solutions in the solution space. As an illustration of the methodology proposal, its performance is compared with the classic approach on a case study, obtaining faster the optimal solution.

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