IEEE/ACM DS-RT 2021

Prof. Vincent Chevrier
Department of Computer Science
University of Lorraine,
France

Title: (Co)simulation of cyber-physical systems with MECSYCO

Date: SEP 27, 10:45 (CET)

Abstract:
Most modeling and simulation (M&S) questions about cyber-physical systems (CPS) require expert skills belonging to different scientific fields. The challenges are then to rigorously integrate each domain's tools (formalism and simulation software) within the rigorous framework of M&S process. Co-simulation is a way to achieve it. During this talk, we position the need for cosimulation and review existing solutions. Then we present the solution we adopted which consists in a DEVS wrapping strategy for heterogenous models/simulators integration. Mecsyco middleware implements all these contributions (mecsyco.com) and was successfully applied for cosimulation of cyberphysical energy systems. Beside a general overview of the MECSYCO possibilities, a special focus will be made on the meaning of distributed and decentralized (Co-)Simulation in the MECSYCO context.

Short Bio:
Vincent Chevrier is full Professor at University of Lorraine, in France and researcher in LORIA Laboratory. His research is focused on complex system modeling and simulation using multi-agent approaches. His current research topics is multi-modeling and cosimulation. He leads the mecsyco software development and applications.

Prof. Edward A. Lee
Distinguished Professor, EECS,
University of California at Berkeley,
USA

Title: Consistency and Availability Tradeoffs in Cyber-Physical Systems

Date: SEP 28, 15:00 (CET)

Abstract:
In distributed systems, Brewer's CAP theorem tells us that when networks become partitioned, there is a tradeoff between consistency and availability. Consistency is agreement on the values of shared variables across a system, and availability is the ability to respond to reads and writes accessing those shared variables. Although this concept is well established in the database community, in this talk, I will show that the same fundamental tradeoff arises in cyber-physical systems. I will describe two distributed coordination mechanisms, implemented as an extension of the Lingua Franca coordination language, that support arbitrary tradeoffs between consistency and availability as network latency varies. In our centralized coordination mechanism, inconsistency remains bounded by a chosen numerical value at the cost that unavailability becomes unbounded under network partitioning. With our decentralized coordination, unavailability remains bounded by a chosen numerical quantity at the cost that inconsistency becomes unbounded under network partitioning.
Our centralized coordination mechanism is an extension of techniques that have historically been used for distributed simulation, an application where consistency is paramount. Our decentralized coordination mechanism is an extension of techniques that have been used in distributed databases when availability is paramount. This talk describes work done jointly with Soroush Bateni (UT Dallas) and Marten Lohstroh (UC Berkeley) with significant contributions from Ravi Akella (Denso) and Christian Menard (TU Dresden).

Short Bio:
Edward A. Lee has been working on embedded software systems for 40 years. After studying and working at Yale, MIT, and Bell Labs, he landed at Berkeley, where he is now Professor of the Graduate School in EECS. His research is focused on cyber-physical systems. He is the lead author of the open-source software system Ptolemy II, author of textbooks on embedded systems and digital communications, and has recently been writing books on philosophical and social implications of technology. His current research is focused on a polyglot coordination language for distributed real-time systems called Lingua Franca that combines features of discrete-event modeling, synchronous languages, and actors.

Prof. Edwin Z. Crues
Simulation and Graphics Branch
NASA Johnson Space Center
Houston, Texas, USA

Title: Returning to the Moon: Plans for Distributed Simulation in the Artemis Program

Date: SEP 29, 15:00 (CET)

Abstract:
It's been almost 50 years since the Apollo program and humans were last present on the Moon. Now, NASA is making plans to lead an international consortium of commercial and governmental partners back with the Artemis program. Just as with Apollo, almost every aspect of the design, development, planning, and execution of the Artemis program will me simulated but in even greater detail. Fortunately, there have been many advances in modeling, simulation, computations, and computer networking in the past 50 years. The Artemis program will benefit from these advances. One of the more exciting areas of development is the ability to create large scale integrated simulations using advancements in multi-processor computing and distributed simulation. The NASA Exploration Systems Simulations (NExSyS) team in the Simulation and Graphics Branch at NASA's Johnson Space Center is working on a suite of Artemis element simulations that can be linked together in a larger distributed simulation to provide early insight into the Artemis architecture, the individual space systems, the interfaces between those systems, and the execution of possible lunar surface mission. This presentation will provide an overview of the Artemis program as currently planned and discuss the architecture, simulation tools, and technologies going into a large scale distributed simulation of the Artemis Base Camp.

Short Bio:
Edwin Z. {Zack} Crues received B.S., M.S., and Ph.D. degrees in Aerospace Engineering from the University of Texas, Austin in 1983, 1985, and 1989 respectively. Zack has over 30 years of professional experience in developing spacecraft simulation and simulation technologies. Zack is currently a member of the Simulation and Graphics branch at NASA’s Johnson Space Center in Houston, Texas where he leads the development of simulation technologies and the application of those technologies in the simulation of NASAs current and proposed human space exploration systems. He has developed hundreds of models and simulations for NASA spacecraft, European Space Agency launch systems, and Japanese Aerospace Exploration Agency spacecraft. Zack’s recent research focus has been developing and applying distributed computation and distributed simulation technologies. This includes a large-scale distributed simulation of NASAs proposed human space exploration missions. Zack is currently the simulation lead for the Human Landing System Crew Compartment Office’s Integrated Simulation team. Zack has received numerous awards from the Simulation Interoperability Standards Organization (SISO) including the SISO Technical Merit Award and from the United States National Aeronautics and Space Agency (NASA) including JSC Director’s Commendation Awards and the NASA Exceptional Engineering Achievement Medal.