The DEVStone Metric: Performance Analysis of DEVS Simulation Engines

The DEVStone benchmark allows us to evaluate the performance of discrete-event simulators based on the DEVS formalism. It provides model sets with different characteristics, enabling the analysis of specific issues of simulation engines. However, this heterogeneity hinders the comparison of the results among studies, as the results obtained on each research work depend on the chosen subset of DEVStone models. We define the DEVStone metric based on the DEVStone synthetic benchmark and provide a mechanism for specifying objective ratings for DEVS-based simulators. This metric corresponds to the average number of times that a simulator can execute a selection of 12 DEVStone models in one minute. The variety of the chosen models ensures we measure different particularities provided by DEVStone. The proposed metric allows us to compare various simulators and to assess the impact of new features on their performance. We use the DEVStone metric to compare some popular DEVS-based simulators

Arquitectura de un sistema integrado para diseño dirigido por modelos en el contexto de internet de las cosas con aplicaciones en medicina

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Arquitectura de Computadores y Automática, leída el 14-10-20222Over the past few years, we have seen how processing and storage architectures become cheaper and more efficient, communication infrastructures become faster and more scalable, and many new ways of interacting with the world around us are being developed. Every day more devices are connected to the network, and the generation of data worldwide is growing exponentially. In this context, the Internet of Things promises to be the new technological revolution, as was the introduction of the network of networks or universal mobile accessibility in tis day...A lo largo de los últimos años hemos visto cómo las arquitecturas de procesamiento y almacenamiento se vuelven más baratas y eficientes, las infraestructuras de comunicación se hacen más rápidas y escalables, y se desarrollan multitud de nuevas formas de interactuar con el mundo que nos rodea. Cada día más dispositivos se conectan a la red, y la generación de datos a nivel mundal está creciendo exponencialmente. En este contexto, el Internet de las cosas promete ser la nueva revolución tecnológica, como en su día lo fue la introducción de la red de redes o la accesibilidad móvil universal...Fac. de InformáticaTRUEunpu

xDEVS: A toolkit for interoperable modeling and simulation of formal discrete event systems

Employing Modeling and Simulation (M&S) extensively to analyze and develop complex systems is the norm today. The use of robust M&S formalisms and rigorous methodologies is essential to deal with complexity. Among them, the Discrete Event System Specification (DEVS) provides a solid framework for modeling structural, behavior and information aspects of any complex system. This gives several advantages to analyze and design complex systems: completeness, verifiability, extensibility, and maintainability. DEVS formalism has been implemented in many programming languages and executable on multiple platforms. In this paper, we describe the features of an M&S framework called xDEVS that builds upon the prevalent DEVS Application Programming Interface (API) for both modeling and simulation layers, promoting interoperability between the existing platform-specific (C++, Java, Python) DEVS implementations. Additionally, the framework can simulate the same model using sequential, parallel, or distributed architectures. The M&S engine has been reinforced with several strategies to improve performance, as well as tools to perform model analysis and verification. Finally, xDEVS also facilitates systems engineers to apply the vision of model-based systems engineering (MBSE), model-driven engineering (MDE), and model-driven systems engineering (MDSE) paradigms. We highlight the features of the proposed xDEVS framework with multiple examples and case studies illustrating the rigor and diversity of application domains it can support

IJMSSC

DEVS is a sound Modeling and Simulation (M&S) framework that describes a model in a modular and hierarchical way. It comes along with an abstract simulation algorithm which defines its operational semantics. Many variants of such an algorithm have been proposed by DEVS researchers. Yet, the proper interpretation and analysis of the computational complexity of such approaches have not been systematically addressed and defined. As systems become larger and more complex, the efficiency of the DEVS simulation algorithms in terms of time complexity measure becomes a major issue. Therefore, it is necessary to devise a method for computing this complexity. This paper proposes a generic method to address such an issue, taking advantage of the recursion embedded in the triggered-by-message principle of the DEVS simulation protocol. The applicability of the method is shown through the complexity analysis of various DEVS simulation algorithms

A new event-driven distributed simulation architecture

Trabajo de Fin de Máster en Máster en Ingeniería Informática, Facultad de Informática UCM, Departamento de Arquitectura de Computadores y Automática, Curso 2019/2020Los computadores actuales son sistemas Multi-Core, en los cuales cada procesador contiene varios núcleos de ejecución. Estos sistemas de memoria compartida pueden utilizarse de manera individual o combinarse para formar un supercomputador de memoria distribuida. Aprovechar estos dos niveles de paralelismo en estas máquinas es importante para conseguir explotar al máximo su capacidad de cálculo, lo que constituye un área de investigación de gran interés en la actualidad. Por otro lado, el paradigma de la computación en la nube ofrece a los usuarios un conjunto casi ilimitado de recursos en un modelo de pago por uso. Para que las aplicaciones que usan este paradigma escalen adecuadamente es necesario proporcionar a los usuarios de estos sistemas herramientas capaces de explotar los recursos contratados, ya sea un procesador de memoria compartida o un clúster de memoria distribuida. Para ello son muy útiles los contenedores, como Docker, que permiten a los desarrolladores de aplicaciones incluir en el contenedor todo el entorno de ejecución. Así, los usuarios pueden disponer de la aplicación correctamente configurada sin más que elegir la imagen adecuada para su sistema. Un grupo de aplicaciones de especial relevancia son los simuladores, que se usan ampliamente en el campo científico para analizar la viabilidad de ciertos sistemas. La simulación, y en particular la simulación de eventos discretos, se ha exportado a la nube durante la última década bajo el paradigma "simulación como servicio". No obstante, se ha demostrado que este formato de simulación es ciertamente limitante, y exclusivo de sistemas grandes, dejando de lado su ejecución en sistemas de memoria compartida. En este trabajo de fin de máster se analizan nuevos protocolos de simulación distribuida desde puntos de vista más pragmáticos, de acuerdo con los desarrollos tecnológicos tanto de los actuales procesadores como de la nube en sí.Today's computers are Multi-Core systems, in which each processor contains several execution cores. These shared memory systems can be used individually or combined to form a distributed memory supercomputer. Taking advantage of these two levels of parallelism in these machines is important in order to get the most out of their computing capacity, which is an area of research of great interest at present. On the other hand, the cloud computing paradigm offers users an almost unlimited set of resources in a pay-per-use model. For applications using this paradigm to scale properly, users of these systems need to be provided with tools capable of exploiting the resources contracted, whether a shared memory processor or a distributed memory cluster. For this purpose, containers, such as Docker, are very useful, allowing application developers to include the entire execution environment in the container. This way, users can have the application correctly configured only having to choose the right image for their system. A group of applications of special relevance are simulators, which are widely used in the scientific field to analyze the viability of certain systems. Simulation, and in particular the simulation of discrete events, has been exported to the cloud over the last decade under the "simulation as a service" paradigm. However, it has been shown that this simulation format is certainly limiting, and exclusive of large systems, leaving aside its execution in shared memory systems. In this Master Thesis work, new distributed simulation protocols are analyzed from a more pragmatic point of view, in accordance with technological developments both in current processors and in the cloud itself.Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaTRUEunpu

Enabling technologies to automate cianobacterial blooms monitoring

[Resumen] Los blooms de cianobacterias son procesos biológicos dinámicos, peligrosos para los habitantes y usuarios de los recursos hídricos, ya que reducen el oxigeno y el alcance de la luz de las masas del agua, y pueden producir toxinas altamente dañinas. La monitorización y la predicción automática de los blooms pueden permitir a las autoridades detectarlos y anticipar la toma de decisiones para mitigar los riesgos que éstos conllevan. El uso de tecnologías como el Modelado & Simulación, los Vehículos Autónomos de Superficie inteligentes, el Internet de las Cosas con computación en el borde, los Gemelos Digitales y la Inteligencia Artificial facilita tanto la monitorización como la predicción y la gestión basada en el conocimiento de la situación real de las masas de agua. Este artículo presenta diferentes avances y proyectos de investigación en estos campos del grupo de Ingeniería de Sistemas, Control, Automatización y Robótica de la Universidad Complutense de Madrid.[Abstract] Cyanobacterial blooms are dynamic biological processes, dangerous for inhabitants and users of water resources, as they reduce the oxygen and light reach in water bodies, and can produce highly harmful toxins. Automatic monitoring and prediction of the blooms can enable authorities to detect them and anticipate their decisions to mitigate the risks that they pose. The use of technologies such as Modeling & Simulation, intelligent Autonomous Surface Vehicles, Internet of Things with edge computing, Digital Twins and Artificial Intelligence facilitates monitoring, prediction and knowledge-based management of the real situation of water bodies. This article presents different advances and research projects in these fields by the Systems Engineering, Control, Automation and Robotics group of the Complutense University of Madrid.Gobierno de la Comunidad de Madrid; Y2020/TCS-6420Ministerio de Ciencia e Innovación; TED2021-130123B-I0

Reconsidering the performance of DEVS modeling and simulation environments using the DEVStone benchmark

The discrete event system specification formalism, which supports hierarchical and modular model composition, has been widely used to understand, analyze and develop a variety of systems. Discrete event system specification has been implemented in various languages and platforms over the years. The DEVStone benchmark was conceived to generate a set of models with varied structure and behavior, and to automate the evaluation of the performance of discrete event system specification-based simulators. However, DEVStone is still in a preliminary phase and more model analysis is required. In this paper, we revisit DEVStone introducing new equations to compute the number of events triggered. We also introduce a new benchmark with a similar central processing unit and memory requirements to the most complex benchmark in DEVStone, but with an easier implementation and with it being more manageable analytically. Finally, we compare both the performance and memory footprint of five different discrete event system specification simulators in two different hardware platforms