44 research outputs found

    Distributed Approaches to Supply Chain Simulation: A Review

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    This is the author accepted manuscript. The final version is available from ACM via the DOI in this recordThe field of Supply Chain Management (SCM) is experiencing rapid strides in the use of Industry 4.0 technologies and the conceptualization of new supply chain configurations for online retail, sustainable and green supply chains and the Circular Economy. Thus, there is an increasing impetus to use simulation techniques such as discrete-event simulation, agent-based simulation and hybrid simulation in the context of SCM. In conventional supply chain simulation, the underlying constituents of the system like manufacturing, distribution, retail and logistics processes are often modelled and executed as a single model. Unlike this conventional approach, a distributed supply chain simulation (DSCS) enables the coordinated execution of simulation models using specialist software. To understand the current state-of-the-art of DSCS, this paper presents a methodological review and categorization of literature in DSCS using a framework-based approach. Through a study of over 130 articles, we report on the motivation for using DSCS, the modelling techniques, the underlying distributed computing technologies and middleware, its advantages and a future agenda, as also limitations and trade-offs that may be associated with this approach. The increasing adoption of technologies like Internet-of-Things and Cloud Computing will ensure the availability of both data and models for distributed decision-making, and which is likely to enable data-driven DSCS of the future. This review aims to inform organizational stakeholders, simulation researchers and practitioners, distributed systems developers and software vendors, as to the current state of the art of DSCS, and which will inform the development of future DSCS using new applied computing approaches

    Proceedings, MSVSCC 2013

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    Proceedings of the 7th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 11, 2013 at VMASC in Suffolk, Virginia

    Fifth Conference on Artificial Intelligence for Space Applications

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    The Fifth Conference on Artificial Intelligence for Space Applications brings together diverse technical and scientific work in order to help those who employ AI methods in space applications to identify common goals and to address issues of general interest in the AI community. Topics include the following: automation for Space Station; intelligent control, testing, and fault diagnosis; robotics and vision; planning and scheduling; simulation, modeling, and tutoring; development tools and automatic programming; knowledge representation and acquisition; and knowledge base/data base integration

    Full Issue: vol. 63, issue 4

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    Discrete Event Simulations

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    Considered by many authors as a technique for modelling stochastic, dynamic and discretely evolving systems, this technique has gained widespread acceptance among the practitioners who want to represent and improve complex systems. Since DES is a technique applied in incredibly different areas, this book reflects many different points of view about DES, thus, all authors describe how it is understood and applied within their context of work, providing an extensive understanding of what DES is. It can be said that the name of the book itself reflects the plurality that these points of view represent. The book embraces a number of topics covering theory, methods and applications to a wide range of sectors and problem areas that have been categorised into five groups. As well as the previously explained variety of points of view concerning DES, there is one additional thing to remark about this book: its richness when talking about actual data or actual data based analysis. When most academic areas are lacking application cases, roughly the half part of the chapters included in this book deal with actual problems or at least are based on actual data. Thus, the editor firmly believes that this book will be interesting for both beginners and practitioners in the area of DES

    A Scalable and Secure System Architecture for Smart Buildings

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    Recent years has seen profound changes in building technologies both in Europe and worldwide. With the emergence of Smart Grid and Smart City concepts, the Smart Building has attracted considerable attention and rapid development. The introduction of novel information and communication technologies (ICT) enables an optimized resource utilization while improving the building performance and occupants' satisfaction over a broad spectrum of operations. However, literature and industry have drawn attention to certain barriers and challenges that inhibit its universal adoption. The Smart Building is a cyber-physical system, which as a whole is more than the sum of its parts. The heterogeneous combination of systems, processes, and practices requires a multidisciplinary research. This work proposes and validates a systems engineering approach to the investigation of the identified challenges and the development of a viable architecture for the future Smart Building. Firstly, a data model for the building management system (BMS) enables a semantic abstraction of both the ICT and the building construction. A high-level application programming interface (API) facilitates the creation of generic management algorithms and external applications, independent from each Smart Building instance, promoting the intelligence portability and lowering the cost. Moreover, the proposed architecture ensures the scalability regardless of the occupant activities and the complexity of the optimization algorithms. Secondly, a real-time message-oriented middleware, as a distributed embedded architecture within the building, empowers the interoperability of the ICT devices and networks and their integration into the BMS. The middleware scales to any building construction regardless of the devices' performance and connectivity limitations, while a secure architecture ensures the integrity of data and operations. An extensive performance and energy efficiency study validates the proposed design. A "building-in-the-loop" emulation system, based on discrete-event simulation, virtualizes the Smart Building elements (e.g., loads, storage, generation, sensors, actuators, users, etc.). The high integration with the message-oriented middleware keeps the BMS agnostic to the virtual nature of the emulated instances. Its cooperative multitasking and immerse parallelism allow the concurrent emulation of hundreds of elements in real time. The virtualization facilitates the development of energy management strategies and financial viability studies on the exact building and occupant activities without a prior investment in the necessary infrastructure. This work concludes with a holistic system evaluation using a case study of a university building as a practical retrofitting estimation. It illustrates the system deployment, and highlights how a currently under development energy management system utilizes the BMS and its data analytics for demand-side management applications

    Monitoring of Honey Bee Colony Losses

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    In recent decades, independent national and international research programs have revealed possible reasons behind the death of managed honey bee colonies worldwide. Such losses are not due to a single factor, but instead are due to highly complex interactions between various internal and external influences, including pests, pathogens, honey bee stock diversity, and environmental changes. Reduced honey bee vitality and nutrition, exposure to agrochemicals, and the quality of colony management contribute to reduced colony survival in beekeeping operations. Our Special Issue (SI) on ‘’Monitoring of Honey Bee Colony Losses” aims to address the specific challenges that honey bee researchers and beekeepers face. This SI includes four reviews, with one being a meta-analysis that identifies gaps in the current and future directions for research into honey bee colonies’ mortalities. Other review articles include studies regarding the impact of numerous factors on honey bee mortality, including external abiotic factors (e.g., winter conditions and colony management) as well as biotic factors such as attacks by Vespa velutina and Varroa destructor

    AGENT-BASED DISCRETE EVENT SIMULATION MODELING AND EVOLUTIONARY REAL-TIME DECISION MAKING FOR LARGE-SCALE SYSTEMS

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    Computer simulations are routines programmed to imitate detailed system operations. They are utilized to evaluate system performance and/or predict future behaviors under certain settings. In complex cases where system operations cannot be formulated explicitly by analytical models, simulations become the dominant mode of analysis as they can model systems without relying on unrealistic or limiting assumptions and represent actual systems more faithfully. Two main streams exist in current simulation research and practice: discrete event simulation and agent-based simulation. This dissertation facilitates the marriage of the two. By integrating the agent-based modeling concepts into the discrete event simulation framework, we can take advantage of and eliminate the disadvantages of both methods.Although simulation can represent complex systems realistically, it is a descriptive tool without the capability of making decisions. However, it can be complemented by incorporating optimization routines. The most challenging problem is that large-scale simulation models normally take a considerable amount of computer time to execute so that the number of solution evaluations needed by most optimization algorithms is not feasible within a reasonable time frame. This research develops a highly efficient evolutionary simulation-based decision making procedure which can be applied in real-time management situations. It basically divides the entire process time horizon into a series of small time intervals and operates simulation optimization algorithms for those small intervals separately and iteratively. This method improves computational tractability by decomposing long simulation runs; it also enhances system dynamics by incorporating changing information/data as the event unfolds. With respect to simulation optimization, this procedure solves efficient analytical models which can approximate the simulation and guide the search procedure to approach near optimality quickly.The methods of agent-based discrete event simulation modeling and evolutionary simulation-based decision making developed in this dissertation are implemented to solve a set of disaster response planning problems. This research also investigates a unique approach to validating low-probability, high-impact simulation systems based on a concrete example problem. The experimental results demonstrate the feasibility and effectiveness of our model compared to other existing systems
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