scholarly journals SysML Models for Discrete Event Logistics Systems

2020 ◽  
Vol 125 ◽  
Author(s):  
Timothy Sprock ◽  
Conrad Bock
Keyword(s):  
Complex Systems ◽  
Discrete Event ◽  
Design Methods ◽  
System Models ◽  
Logistics Systems ◽  
Model Based ◽  
Systems Model ◽  
Analysis Models ◽  
The Way

System models and model-based engineering methods have the promise of transforming the way that industrial engineers interact with production and logistics systems. Model-based methods play a role in improving communication between stakeholders, interoperability between systems, automated access to consistent analysis models, and multi-disciplinary design methods for complex systems. However, there remains a need for a foundation for modeling these kinds of systems – a foundation that tailors methods and tools developed in other engineering domains to the unique concepts and semantics of production and logistics. This foundation is the topic of these models.

scholarly journals A DECENTRALIZED MODEL-BASED DIAGNOSTIC TOOL FOR COMPLEX SYSTEMS

2002 ◽  
Vol 11 (03) ◽  
pp. 327-346 ◽  
Author(s):  
Y. PENCOLÉ ◽  
M.-O. CORDIER ◽  
L. ROZÉ
Keyword(s):  
Complex Systems ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Global Model ◽  
Telecommunication Networks ◽  
Model Based ◽  
On Line ◽  
The Impact ◽  
Decentralized Model ◽  
Merging Strategy

We address the problem of diagnosing complex discrete-event systems such as telecommunication networks. Given a flow of observations from the system, the goal is to explain those observations by identifying and localizing possible faults. Several model-based diagnosis approaches deal with this problem but they need the computation of a global model which is not feasible for complex systems like telecommunication networks. Our contribution is the proposal of a decentralized approach which permits to carry out an on-line diagnosis without computing the global model. This paper describes the implementation of a tool based on this approach. Given a decentralized model of the system and a flow of observations, the program analyzes the flow and computes the diagnosis in a decentralized way. The impact of the merging strategy on the global efficiency is demonstrated and illustrated by experimental results on a real application.

Failure Logic Modeling Techniques Based on DEVS

2014 ◽  
Vol 631-632 ◽  
pp. 265-270
Author(s):  
Qiang Sun ◽  
Jian Jiao ◽  
Shan Shan Zhou
Keyword(s):  
Complex Systems ◽  
Propagation Path ◽  
Potential Hazard ◽  
Logical Model ◽  
Component Failure ◽  
Logic Modeling ◽  
Model Based ◽  
Systems Model ◽  
Modeling Techniques ◽  
Failure Propagation

To identify the component failure propagation path in complex systems, a component failure logical model based on DEVS was established by combining the failure logic principle and DEVS formal specification at the next granularity level of component hierarchy. A series of components failure states define a potential hazard. DEVS has modeling advantages of standardized, hierarchical and modular. Basing on its own characteristics,it can be used to study failure logic modeling techniques of complex systems, model and analyse the scene of the accident process. Therefore, the paper describes syntax and semantics of component failure logic and atomic DEVS, focusing on the implementation mechanism of failure logic using DEVS, the establishment of component state space, the trigger mechanism and the corresponding output in order to establish a component failure logical model based on DEVS. At last, a Wheel Brake System is used to verify the applicability and validity of the model.

scholarly journals Semantic adaptation for FMI co-simulation with hierarchical simulators

SIMULATION ◽  
2018 ◽  
Vol 95 (3) ◽  
pp. 241-269 ◽  
Author(s):  
Cláudio Gomes ◽  
Bart Meyers ◽  
Joachim Denil ◽  
Casper Thule ◽  
Kenneth Lausdahl ◽  
...  
Keyword(s):  
Intellectual Property ◽  
Complex Systems ◽  
Development Time ◽  
Model Based ◽  
Simulation Techniques ◽  
Semantic Adaptation ◽  
Definition Of ◽  
Minimal Effort ◽  
The Way ◽  
Inputs And Outputs

Model-based design can shorten the development time of complex systems by the use of simulation techniques. However, it can be hard to simulate the system as a whole if it is developed in a concurrent fashion by multiple and specialized teams. Co-simulation, with the support of the Functional Mockup Interface (FMI) Standard, is proposed as a way to promote tool interoperability while protecting the intellectual property of subsystems. The standard allows uniform communication between subsystem simulators, but does not state how the inputs and outputs should be interpreted, nor how the subsystems should interact correctly. Semantic adaptations can be quickly made to correct the interactions with subsystem simulators that were produced with different assumptions, and avoid changing those subsystems, their simulators, or the orchestration algorithm that computes the co-simulation. In this work, we explore how to describe common adaptations and what their meaning is in the context of FMI co-simulation. The result is a sound language that enables the implementation of adaptations with minimal effort. A distinct feature is that it describes adaptations for groups of interconnected subsystem simulators in the same way as for a single simulator, and the implementation is itself a simulator, thanks to a sound definition of hierarchical co-simulation. This work paves the way for research into the correct combination and interfacing of different adaptations.

Model-Based and Model-Free Social Cognition

2019 ◽  
Author(s):  
Leor M Hackel ◽  
Jeffrey Jordan Berg ◽  
Björn Lindström ◽  
David Amodio
Keyword(s):  
Reinforcement Learning ◽  
Social Cognition ◽  
Learning Strategies ◽  
Memory Systems ◽  
Learning Task ◽  
Financial Advisors ◽  
Model Based ◽  
Model Free ◽  
Systems Model ◽  
Task Assessment

Do habits play a role in our social impressions? To investigate the contribution of habits to the formation of social attitudes, we examined the roles of model-free and model-based reinforcement learning in social interactions—computations linked in past work to habit and planning, respectively. Participants in this study learned about novel individuals in a sequential reinforcement learning paradigm, choosing financial advisors who led them to high- or low-paying stocks. Results indicated that participants relied on both model-based and model-free learning, such that each independently predicted choice during the learning task and self-reported liking in a post-task assessment. Specifically, participants liked advisors who could provide large future rewards as well as advisors who had provided them with large rewards in the past. Moreover, participants varied in their use of model-based and model-free learning strategies, and this individual difference influenced the way in which learning related to self-reported attitudes: among participants who relied more on model-free learning, model-free social learning related more to post-task attitudes. We discuss implications for attitudes, trait impressions, and social behavior, as well as the role of habits in a memory systems model of social cognition.

Design of rural water systems using dynamic models

1999 ◽  
Vol 39 (4) ◽  
pp. 221-231
Author(s):  
A. H. Lobbrecht
Keyword(s):  
Dynamic Models ◽  
Water System ◽  
Design Procedure ◽  
Real Data ◽  
Water Systems ◽  
Design Methods ◽  
Water Quality Criteria ◽  
Rural Water ◽  
Rural Water Systems ◽  
The Way

The properties of main water ways and infrastructure of rural water systems are often determined by very general design methods. These methods are based on standards that use only little information of the actual water system. Most design methods applied in the Netherlands are based on land use and soil texture. Standards have been developed on the basis of generalized properties of water systems. Details of the actual layout of the water system and the way in which that system is controlled, are usually not incorporated. Present-day dynamic simulation programs and the computer power currently available enable more detailed modeling and incorporation of location-specific data into models. Such models can be used to design the water system and can include real data. A model-based design method is introduced, in which the actual situation of the water system is taken into consideration as well as the way in which the water system is controlled. Stochastics concerning the operation and availability of controlling infrastructure are included in the method. Models can be evaluated by including real data. In this way the actual safety of the water system, for example during floods, can be determined. Water-quantity design criteria can be incorporated as well as water-quality criteria. Application of the method makes it possible to design safe water systems in which excess capacities are avoided and in which all requirements of interest are met. The method, called the ‘dynamic design procedure’, can result in considerable savings for water authorities when new systems have to be designed or existing designs have to be reconsidered.

scholarly journals A journey from reductionist to systemic cell biology aboard the schooner Tara

2012 ◽  
Vol 23 (13) ◽  
pp. 2403-2406 ◽  
Author(s):  
Eric Karsenti
Keyword(s):  
Complex Systems ◽  
Molecular Interactions ◽  
Cell Biology ◽  
Statistical Physics ◽  
Interaction Networks ◽  
Cellular Functions ◽  
Personal Journey ◽  
New Approaches ◽  
The World ◽  
The Way

In this essay I describe my personal journey from reductionist to systems cell biology and describe how this in turn led to a 3-year sea voyage to explore complex ocean communities. In describing this journey, I hope to convey some important principles that I gleaned along the way. I realized that cellular functions emerge from multiple molecular interactions and that new approaches borrowed from statistical physics are required to understand the emergence of such complex systems. Then I wondered how such interaction networks developed during evolution. Because life first evolved in the oceans, it became a natural thing to start looking at the small organisms that compose the plankton in the world's oceans, of which 98% are … individual cells—hence the Tara Oceans voyage, which finished on 31 March 2012 in Lorient, France, after a 60,000-mile around-the-world journey that collected more than 30,000 samples from 153 sampling stations.

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