Simulation in the Cloud Using Handheld Devices

International audienceIn recent years, numerous applications have been deployed into mobile devices. However, until now, there have been no attempts to run simulations on handheld devices. We want investigate different architectures for running and managing simulations on handheld devices, and putting the simulation services in the Cloud. We propose a hybrid simulation and visualization approach, where a dedicated mobile application is running on the client side and the RISE simulation server is hosted in the Cloud. In particular, with our prototype, we explore the remote management of a simulation tool using a dedicated native application running on an Android Smartphone, and showing the evolution of a simulation model for a forest fire spread, mashing-up the generated graphics with online GIS services

A novel parallelization technique for DEVS simulation of continuous and hybrid systems.

In this paper, we introduce a novel parallelization technique for Discrete Event System Specification (DEVS) simulation of continuous and hybrid systems. Here, like in most parallel discrete event simulation methodologies, the models are first split into several sub-models which are than concurrently simulated on different processors. In order to avoid the cost of the global synchronization of all processes, the simulation time of each sub-model is locally synchronized in a real-time fashion with a scaled version of physical time, which implicitly synchronizes all sub-models. The new methodology, coined Scaled Real-Time Synchronization (SRTS), does not ensure a perfect synchronization in its implementation. However, under certain conditions, the synchronization error introduced only provokes bounded numerical errors in the simulation results. SRTS uses the same physical time-scaling parameter throughout the entire simulation. We also developed an adaptive version of the methodology (Adaptive-SRTS) where this parameter automatically evolves during the simulation according to the workload. We implemented the SRTS and Adaptive-SRTS techniques in PowerDEVS , a DEVS simulation tool, under a real-time operating system called the Real-Time Application Interface (RTAI) . We tested their performance by simulating three large-scale models, obtaining in all cases a considerable speedup.Fil: Bergero, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; ArgentinaFil: Kofman, Ernesto Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; ArgentinaFil: Cellier, François. Swiss Federal Institute Of Technology Zurich. Departament Informatik. Modeling And Simulation Research Group; Suiz

Data Assimilation Based on Sequential Monte Carlo Methods for Dynamic Data Driven Simulation

Simulation models are widely used for studying and predicting dynamic behaviors of complex systems. Inaccurate simulation results are often inevitable due to imperfect model and inaccurate inputs. With the advances of sensor technology, it is possible to collect large amount of real time observation data from real systems during simulations. This gives rise to a new paradigm of Dynamic Data Driven Simulation (DDDS) where a simulation system dynamically assimilates real time observation data into a running model to improve simulation results. Data assimilation for DDDS is a challenging task because sophisticated simulation models often have: 1) nonlinear non-Gaussian behavior 2) non-analytical expressions of involved probability density functions 3) high dimensional state space 4) high computation cost. Due to these properties, most existing data assimilation methods fail to effectively support data assimilation for DDDS in one way or another. This work develops algorithms and software to perform data assimilation for dynamic data driven simulation through non-parametric statistic inference based on sequential Monte Carlo (SMC) methods (also called particle filters). A bootstrap particle filter based data assimilation framework is firstly developed, where the proposal distribution is constructed from simulation models and statistical cores of noises. The bootstrap particle filter-based framework is relatively easy to implement. However, it is ineffective when the uncertainty of simulation models is much larger than the observation model (i.e. peaked likelihood) or when rare events happen. To improve the effectiveness of data assimilation, a new data assimilation framework, named as the SenSim framework, is then proposed, which has a more advanced proposal distribution that uses knowledge from both simulation models and sensor readings. Both the bootstrap particle filter-based framework and the SenSim framework are applied and evaluated in two case studies: wildfire spread simulation, and lane-based traffic simulation. Experimental results demonstrate the effectiveness of the proposed data assimilation methods. A software package is also created to encapsulate the different components of SMC methods for supporting data assimilation of general simulation models

Distributed Web Service Coordination for Collaboration Applications and Biological Workflows

In this dissertation work, we have investigated the main research thrust of decentralized coordination of workflows over web services. To address distributed workflow coordination, first we have developed “Web Coordination Bonds” as a capable set of dependency modeling primitives that enable each web service to manage its own dependencies. Web bond primitives are as powerful as extended Petri nets and have sufficient modeling and expressive capabilities to model workflow dependencies. We have designed and prototyped our “Web Service Coordination Management Middleware” (WSCMM) system that enhances current web services infrastructure to accommodate web bond enabled web services. Finally, based on core concepts of web coordination bonds and WSCMM, we have developed the “BondFlow” system that allows easy configuration distributed coordination of workflows. The footprint of the BonFlow runtime is 24KB and the additional third party software packages, SOAP client and XML parser, account for 115KB

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

Toward composing variable structure models and their interfaces: a case of intensional coupling definitions

In this thesis, we investigate a combination of traditional component-based and variable structure modeling. The focus is on a structural consistent specification of couplings in modular, hierarchical models with a variable structure. For this, we exploitintensional definitions, as known from logic, and introduce a novel intensional coupling definition, which allows a concise yet expressive specification of complex communication and interaction patterns in static as well as variable structure models, without the need to worryabout structural consistency.In der Arbeit untersuchen wir ein Zusammenbringen von klassischer komponenten-basierter und variabler Strukturmodellierung. Der Fokus liegt dabei auf der Spezifikation von strukturkonsistenten Kopplungen in modular-hierarchischen Modellen mit einer variablen Struktur. Dafür nutzen wir intensionale Definitionen, wie sie aus der Logik bekannt sind, und führen ein neuartiges Konzept von intensionalen Kopplungen ein, welches kompakte gleichzeitig ausdrucksstarke Spezifikationen von komplexen Kommunikations- und Interaktionsmuster in statischen und variablen Strukturmodellen erlaubt

Review of Open Source Simulators in ICS/IIoT Security Context

In industrial control systems (ICS), simulation has found widespread use during system design and in tuning process control parameters or exploring the effects of new control algorithms. Simulation enables the assessment of performance at scale and allows research to be conducted by those with limited access to real physical infrastructures. However, as ICSs are often no longer isolated from other networks and the internet, hence are subject to security and safety issues, simulation is also required to understand the issues and their solution. To foster transparent, collaborative and cost-effective studies, demonstrations, and solution development, and attract the broadest interest base, simulation is indeed critical and Open Source is a good way to go since simulators in this category are less expensive to access, install, and use, and can be run with general purpose (non-proprietary) computing equipment and setups. Findings This research presents the following key findings: 1. A lot of Open Source simulation tools exist and span applications areas such as communications and sensor networks (C&WSNs), ICS/SCADA, and IIoT. 2. The functional structures and characteristics that appear common in Open Source simulators include: supported licence types, programming languages, operating systems platforms, user interface types, and available documentation and types. 3. Typical research around Open Source simulators is built around modelling, analysis and optimisation of operations in relations to factors such as flexibility, mobility, scalability, and active user support. No single Open Source simulator addresses all conceivable characteristics. While some are strong in specific contexts relative to their development, they are often weak in other purpose-based research capabilities, especially in the context of IoT. 4. Most of the reviewed Open Source tools are not designed to address security contexts. The few that address security such as SCADASim only consider very limited contexts such as testing and evaluating Denial-of-Service (DoS), Man-in-the-middle (Mitm), Eavesdropping, and Spoofing attacks. Recommendations The following key recommendations are presented: 1. Future developments of Open Source simulators (especially for IIoT) should explore the potential for functionalities that can enable the integration of diverse simulators and platforms to achieve an encompassing setup. 2. Developers should explore the capabilities of generic simulators towards achieving architectures with expansible capabilities into multi-class domains, support easier and faster modelling of complex systems, and which can attract varied users and contributors. 3. Functional characteristics such as; ease of use, degree of community acceptance and use, and suitability for industrial applications, should also be considered as selection and development criteria, and to emphasise simulator effectiveness. This can support consistency, credibility, and simulation system relevance within a domain that is continually evolving. 4. Future Open Source simulation projects developments should consider and adopt the more common structural attributes including; Platform Type, Open Source Licence Type, Programming Language, User Interfaces, Documentation, and Communication Types. These should be further complemented by appropriate editorial controls spanning quality coding, revision control and effective project disseminations and management, to boost simulation tool credibility and wide acceptance. 5. The range of publication dates (earliest to latest) for: citations, code commits, and number of contributors associated to Open Source simulator projects can also support the decision for interests and adoption of specific Open Source projects. 6. Research objectives for ICS/IIoT Open Source simulators should also include security performance and optimisation with considerations towards enhancing confidentiality, integrity and availability. 7. Further studies should explore the evaluation of security topics which could be addressed by simulation – more specifically, proposing how this may be achieved and identifying what can't be addressed by simulation. Investigations into simulation frameworks that can allow multi-mode simulations to be configured and operated are also required. Research into Industry 4.0 System-of-Systems (SoS) security evaluations, dependency, and cascading impacts method or analysis is another area of importanc