27 research outputs found

    A Computerized Constructionist Approach To Simulation And Modeling Pedagogy

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    A major limitation in traditional class lectures on simulation and modeling, that uses assignments, handouts, transparencies, and textbooks, is that students often are unable to appreciate the "experience" of simulating a real problem.  This limitation can be overcome by using an active real case study approach to allow students to simulate a real-time queuing problem through interactive visual simulation software (EXTEND®).  Actual raw data had been collected prior to the case assignment and students are taught to develop the simulation model, based on the actual raw data.  The intent is that by "doing" or "constructing" the simulation model from actual data, the students will understand better and remember

    Design and Planning of Manufacturing Networks for Mass Customisation and Personalisation: Challenges and Outlook

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    AbstractManufacturers and service providers are called to design, plan and operate globalized manufacturing networks, addressing to challenges such as ever-decreasing lifecycles and increased product complexity. These factors, caused primarily by mass customisation and demand volatility, generate a number of issues related to the design and planning of manufacturing systems and networks, which are not holistically tackled in industrial and academic practices. The mapping of production performance requirements to process and production planning requires automated closed-loop control systems, which current systems fail to deliver. Technology-based business approaches are an enabler for increased enterprise performance. Towards that end, the issues discussed in this paper focus on challenges in the design and planning of manufacturing networks in a mass customization and personalization landscape. The development of methods and tools for supporting the dynamic configuration and optimal routing of manufacturing networks and facilities under cost, time, complexity and environmental constraints to support product-service personalization are promoted

    How simulation modelling can help reduce the impact of COVID-19

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    Modelling has been used extensively by all national governments and the World Health Organisation in deciding on the best strategies to pursue in mitigating the effects of COVID-19. Principally these have been epidemiological models aimed at understanding the spread of the disease and the impacts of different interventions. But a global pandemic generates a large number of problems and questions, not just those related to disease transmission, and each requires a different model to find the best solution. In this article we identify challenges resulting from the COVID-19 pandemic and discuss how simulation modelling could help to support decision-makers in making the most informed decisions. Modellers should see the article as a call to arms and decision-makers as a guide to what support is available from the simulation community

    Exposing students to a simulation of the online platform used by the South African revenue service

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    Purpose – Students completing their tertiary education at a university may be equipped with theoretical knowledge with little to no practical experience. In order to bridge this gap in practical skills, a computer simulation was developed based on the e-filing platform of the South African Revenue Services (SARS). Students were exposed to this self-developed computer simulation to answer the question: to what extent will the e-filing simulation improve students' confidence to practically apply their theoretical knowledge? Design/methodology/approach – The research applied a pre–post questionnaire research method to gauge the students' ability to apply their theoretical knowledge to a practical scenario before and after the simulation. Findings – From the results, it is apparent that the students were inspired with confidence in getting to terms with the application of their theoretical knowledge in a real-life scenario. The computer simulation provided the platform for learning to take place in a practical environment without the risk of errors that would translate into real financial consequences. Originality/value – The contribution of this research can be found in a teaching intervention that may support the training of future tax professionals in practical application skills. The contribution can be extended to the enhancement of education in the field of taxation, particularly with the results' showing that the students experienced high levels of increased confidence in their application of theoretical knowledge to real-life scenarios

    A Content Analysis-Based Approach to Explore Simulation Verification and Identify Its Current Challenges

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    Verification is a crucial process to facilitate the identification and removal of errors within simulations. This study explores semantic changes to the concept of simulation verification over the past six decades using a data-supported, automated content analysis approach. We collect and utilize a corpus of 4,047 peer-reviewed Modeling and Simulation (M&S) publications dealing with a wide range of studies of simulation verification from 1963 to 2015. We group the selected papers by decade of publication to provide insights and explore the corpus from four perspectives: (i) the positioning of prominent concepts across the corpus as a whole; (ii) a comparison of the prominence of verification, validation, and Verification and Validation (V&V) as separate concepts; (iii) the positioning of the concepts specifically associated with verification; and (iv) an evaluation of verification\u27s defining characteristics within each decade. Our analysis reveals unique characterizations of verification in each decade. The insights gathered helped to identify and discuss three categories of verification challenges as avenues of future research, awareness, and understanding for researchers, students, and practitioners. These categories include conveying confidence and maintaining ease of use; techniques\u27 coverage abilities for handling increasing simulation complexities; and new ways to provide error feedback to model users

    Road2CPS priorities and recommendations for research and innovation in cyber-physical systems

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    This document summarises the findings of the Road2CPS project, co-financed by the European Commission under the H2020 Research and Innovation Programme, to develop a roadmap and recommendations for strategic action required for future deployment of Cyber-Physical Systems (CPS). The term Cyber-Physical System describes hardware-software systems, which tightly couple the physical world and the virtual world. They are established from networked embedded systems that are connected with the outside world through sensors and actuators and have the capability to collaborate, adapt, and evolve. In the ARTEMIS Strategic Research Agenda 2016, CPS are described as ‘Embedded Intelligent ICT Systems’ that make products smarter, more interconnected, interdependent, collaborative, and autonomous. In the future world of CPS, a huge number of devices connected to the physical world will be able to exchange data with each other, access web services, and interact with people. Moreover, information systems will sense, monitor and even control the physical world via Cyber-Physical Systems and the Internet of Things (HiPEAC Vision 2015). Cyber-Physical Systems find their application in many highly relevant areas to our society: multi-modal transport, health, smart factories, smart grids and smart cities amongst others. The deployment of Cyber-Physical Systems (CPS) is expected to increase substantially over the next decades, holding great potential for novel applications and innovative product development. Digital technologies have already pervaded day-to-day life massively, affecting all kinds of interactions between humans and their environment. However, the inherent complexity of CPSs, as well as the need to meet optimised performance and comply with essential requirements like safety, privacy, security, raises many questions that are currently being explored by the research community. Road2CPS aims at accelerating uptake and implementation of these efforts. The Road2CPS project identifying and analysing the relevant technology fields and related research priorities to fuel the development of trustworthy CPS, as well as the specific technologies, needs and barriers for a successful implementation in different application domains and to derive recommendations for strategic action. The document at hand was established through an interactive, community-based approach, involving over 300 experts from academia, industry and policy making through a series of workshops and consultations. Visions and priorities of recently produced roadmaps in the area of CPS, IoT (Internet of Things), SoS (System-of-Systems) and FoF (Factories of the Future) were discussed, complemented by sharing views and perspectives on CPS implementation in application domains, evolving multi-sided eco-systems as well as business and policy related barriers, enablers and success factors. From the workshops and accompanying activities recommendations for future research and innovation activities were derived and topics and timelines for their implementation proposed. Amongst the technological topics, and related future research priorities ‘integration, interoperability, standards’ ranged highest in all workshops. The topic is connected to digital platforms and reference architectures, which have already become a key priority theme for the EC and their Digitisation Strategy as well as the work on the right standards to help successful implementation of CPSs. Other themes of very high technology/research relevance revealed to be ‘modelling and simulation’, ‘safety and dependability’, ‘security and privacy’, ‘big data and real-time analysis’, ‘ubiquitous autonomy and forecasting’ as well as ‘HMI/human machine awareness’. Next to this, themes emerged including ‘decision making and support’, ‘CPS engineering (requirements, design)’, ‘CPS life-cycle management’, ‘System-of-Systems’, ‘distributed management’, ‘cognitive CPS’, ‘emergence, complexity, adaptability and flexibility’ and work on the foundations of CPS and ‘cross-disciplinary research/CPS Science’

    DISCRETE-EVENT SIMULATION MODELS FOR DIDACTIC SUPPORT

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    This paper presents the evaluation of a discrete event simulation model designed to be used as a didactic aid instrument in classes of a technical course on high school. The simulation model was developed using the free version of the Arena software. Among the results obtained, it was found that applying this model as a didactic resource in classes has enabled an increase of quality in the students’ learning. This result was even more significant concerning students with average grades below 6. In these cases, with the help of the simulator, students of worse educational achievement obtained performance close to the ones that had average grades equal to or higher than 8

    Air Flow and Rain Water Penetration Analysis on Generator Enclosures Using CFD Simulations

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    Rain water penetration testing on power generator units requires a number of complicated procedures, requiring many resources. As such, a Computational Fluid Dynamics (CFD) tool, FloEFD for Creo is used to study the water penetration behavior on a OM924 diesel power generator enclosure in a computational environment. First, the three governing equations in fluid dynamics are derived and explained using simple methods. Next, behavior of rain water droplets upon impact is briefly discussed. Air velocity, volumetric flow rate and static pressure drop were measured physically in the OM924 generator enclosure. Then, a CFD model for the OM924 enclosure was developed and validated using the measured data. Using the particle studies option in FloEFD, rain water penetration studies were conducted on the CFD model. The terminal velocity of the droplets was assumed as a function of droplet diameter and the co-efficient of restitution was measured using basic observational methods. In an enclosure, the water penetration can be explained using three methods; free flowing, dripping and splashing. Each of the methods was tested using water droplet diameters that ranged from 0.1 to 2.5 mm. Results verified that the current baffle plate design was capable of preventing water penetration with the exception of those droplets with the smallest diameters

    Animating Unpredictable Effects

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    Uncanny computer-generated animations of splashing waves, billowing smoke clouds, and characters’ flowing hair have become a ubiquitous presence on screens of all types since the 1980s. This Open Access book charts the history of these digital moving images and the software tools that make them. Unpredictable Visual Effects uncovers an institutional and industrial history that saw media industries conducting more private R&D as Cold War federal funding began to wane in the late 1980s. In this context studios and media software companies took concepts used for studying and managing unpredictable systems like markets, weather, and fluids and turned them into tools for animation. Unpredictable Visual Effects theorizes how these animations are part of a paradigm of control evident across society, while at the same time exploring what they can teach us about the relationship between making and knowing

    MODELING HYPERBARIC CHAMBER ENVIRONMENT AND CONTROL SYSTEM

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    Deep water activities are essential for many industrial fields, for instance in repairing and installation of underwater cables, pipes and constructions, marine salvage and rescue opera- tions. In some cases, these activities must be performed in deep water and hence require special equipment and prepared and experienced personnel. In some critical situations, re- motely controlled vehicles (ROVs) can't be used and a human diver intervention is required. In the last case, divers are required to perform work at high depths, which could be as low as 300m below the water surface. Usually, this is the limit depth for commercial diving and when operations must be carried out even deeper, ROVs remain only possibility to perform them. In the past, the safety regulations were less strict and numerous operations on depth of 300-350 meters of seawater were conducted. However, in the beginning of the 90s gov- ernments and companies started to impose limits on depths of operation; for instance, in Norway maximum operational depth for saturation divers is limited to 180 meters of sea- water (Imbert et al., 2019). Obviously, harsh environmental conditions impose various limitations on performed activi- ties; indeed, low temperature, poor visibility and high pressure make it difficult not only to operate at depth, but even to achieve the point of intervention. One of the main problems is related to elevated pressure, which rises for about 1 bar for each 10 meters of water depth and could achieve up to 20-25 bars at required depth, while pressure inside divers\u2019 atmospheric diving suites must be nearly the same. Considering this, there are several evident limitations. First is related to the fact that at high atmospheric pressure oxy- gen becomes poisonous for human body and special breath gas mixtures are required to avoid health issues. The second one is maximum pressure variation rate which would not cause damage for the human body; indeed, fast compression or decompression could easily cause severe damages and even death of divers. Furthermore, surveys found that circa 1/3 of divers experience headache during decompression which usually last for at least several hours and up to several days (Imbert et al., 2019). The same study indicates that majority of the divers experience fatigue after saturation and it lasts on average more than 4 days before return to normal. Obviously, risk of accidents increases with high number of compression- decompression cycles. To address these issues, in commercial deep water diving the common practice is to perform pressurization only one time before the start of the work activity which typically lasts 20-30 days and consequent depressurization after its end. Hence, divers are living for several weeks in isolated pressurized environments, typically placed on board of a Dive Support Vessel (DSV), usually barge or a ship, and go up and down to the workplace using submersible decompression chamber also known as the bell. While long-term work shifts provide numerous advantages, there is still necessity to perform life support supervision of the plant, the bell and the diving suits, which require presence of well qualified personnel. Currently, most of training activities are performed on empty plant during idle time, but obviously this approach is low efficient and costly, as well as accom- panied by the risk to broke equipment. To address such issues, this research project proposes utilization of simulator of plant and its life support system, devoted to train future Life-Support Supervisors (LSS), taking into account gas dynamics, human behaviour and physiology as well as various aspect of opera- tion of saturation diving plants
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