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11th European conference on Antennas and Propagation (EUCAP)

作者： Koziel, Slawomir Bekasiewicz, Adrian Cheng, Qingsha S. Li, Song Reykjavik Univ Engn Optimizat & Modeling Ctr IS-101 Reykjavik Iceland Southern Univ Sci & Technol Dept Elect & Elect Engn Shenzhen Peoples R China Univ Regina Dept Elect Syst Engn Regina SK Canada

ISBN: (纸本)9788890701870

In this paper, size reduction of antenna structures taking reflection response and total efficiency into account has been investigated. In order to find available design trade-offs concerning the antenna footprint, its wideband matching, and efficiency, numerical optimization has been employed. Appropriate formulation of the objective function permits identification of the designs that exhibit the minimum possible footprint while maintaining the maximum in-band reflection and average efficiency within the prescribed thresholds. For the sake of demonstration, a specific case study of a UWB monopole is considered. A set of designs generated using the proposed approach provides a designer with a comprehensive knowledge about the capabilities of a given antenna topology and facilitates a decision making process driven by a particular application and performance requirements.

关键词： Antenna design ultra-wideband antennas simulation-driven optimization size reduction wideband matching antenna efficiency

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Quantitative driven optimization of a Time Warp Kernel 17

Quantitative Driven Optimization of a Time Warp Kernel

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5th ACM SIGSIM conference on Principles of Advanced Discrete simulation (SIGSIM-PADS)

作者： Gupta, Sounak Wilsey, Philip A. Dept EECS POB 210030 Cincinnati OH 45110 USA

ISBN: (纸本)9781450344890

The set of events available for execution in a Parallel Discrete Event simulation (PDES) are known as the pending event set. In a Time Warp synchronized simulation engine, these pending events are scheduled for execution in an aggressive manner that does not strictly enforce the causal relations between events. One of the key principles of Time Warp is that this relaxed causality will result in the processing of events in a manner that implicitly satisfies their causal order without paying the overhead costs of a strict enforcement of their causal order. On a shared memory platform the event scheduler generally attempts to schedule all available events in their Least TimeStamp First (LTSF) order to facilitate event processing in their causal order. By following an LTSF scheduling policy, a Time Warp scheduler can generally process events so that: (i) the critical path of the event timestamps is scheduled as early as possible, and (ii) causal violations occur infrequently. While this works effectively to minimize rollback (triggered by causal violations), as the number of parallel threads increases, the contention to the shared data structures holding the pending events can have significant negative impacts on overall event processing throughput. This work examines the application of profile data taken from Discrete-Event simulation (DES) models to drive the simulation kernel optimization process. In particular, we take profile data about events in the schedule pool from three DES models to derive alternate scheduling possibilities in a Time Warp simulation kernel. Profile data from the studied DES models suggests that in many cases each Logical Process (LP) in a simulation will have multiple events that can be dequeued and executed as a set. In this work, we review the profile data and implement group event scheduling strategies based on this profile data. Experimental results show that event group scheduling can help alleviate contention and improve performance. Ho

关键词： Pending event set Profile Guided optimization Event Scheduling Lock contention Parallel and distributed simulation Time warp

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Lean NO_x Trap Regeneration Control: A data-driven MPC Approach 56

Lean NO<sub>x</sub> Trap Regeneration Control: A data-driven...

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56th Annual IEEE conference on Decision and Control (CDC)

作者： Karimshoushtari, Milad Novara, Carlo Politecn Torino Turin Italy

ISBN: (纸本)9781509028733

Lean NOx Trap (LNT) is one of the most effective after-treatment technologies used to reduce NOx emissions of diesel engines. One relevant problem in this context is LNT regeneration timing control. This problem is indeed difficult due to the fact that LNTs are highly nonlinear systems, involving complex physical/chemical processes, that are hard to model. In this paper, a novel approach for regeneration timing of LNTs is proposed, allowing us to overcome these issues. This approach, named data-driven model predictive control (D-2-MPC), does not require a physical model of the engine/trap system but is based on low-complexity polynomial prediction models, directly identified from data. The regeneration timing is computed through an optimization algorithm, which uses the identified models to predict the LNT behavior. Two D-2-MPC strategies are proposed, and tested in a co-simulation study, where the plant is represented by a detailed LNT model, built using the well-known commercial tool AMEsim, and the controller is implemented in Matlab/Simulink.

关键词： Mathematical model Predictive models Engines Fuels Timing Computational modeling Data models

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SURROGATE ASSISTED CALIBRATION FRAMEWORK FOR CROWD MODEL CALIBRATION

SURROGATE ASSISTED CALIBRATION FRAMEWORK FOR CROWD MODEL CAL...

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Winter simulation conference (WSC)

作者： Yi, Wenchao Zhong, Jinghui Tan, Singkuang Cai, Wentong Hu, Nan Nanyang Technol Univ Sch Comp Sci & Engn 50 Nanyang Ave Singapore 639798 Singapore South China Univ Technol Sch Comp Sci & Engn 381 Wushan Lu Guangzhou 510640 Guangdong Peoples R China Agcy Sci Technol & Res Inst High Performance Comp 1 Fusionopolis Way16-16 Connexis North Singapore 138632 Singapore

ISBN: (纸本)9781538634288

Surrogate models are commonly used to approximate the multivariate input or output behavior of complex systems. In this paper, surrogate assisted calibration frameworks are proposed to calibrate the crowd model. To integrate the surrogate models into the evolutionary calibration framework, both the offline and online training based approaches are developed. The offline training needs to generate training set in advance, while the online training can adaptively build and re-build the surrogate model along the evolutionary process. Our simulation results demonstrate that the surrogate assisted calibration framework with the online training is effective and the surrogate model using artificial neural network obtains the best overall performance in the scenario evaluated in the case study.

关键词： Calibration Training Evolutionary computation optimization Computational modeling Adaptation models Kernel

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Parallel fuzzy cellular automata for data-driven simulation of wildfire spreading

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JOURNAL OF COMPUTATIONAL SCIENCE 2017年 21卷 469-485页

作者： Ntinas, Vasileios G. Moutafis, Byron E. Trunfio, Giuseppe A. Sirakoulis, Georgios Ch. Democritus Univ Thrace Sch Engn Dept Elect & Comp Engn Univ Campus GR-67100 Xanthi Greece Univ Sassari Dept Architecture Planning & Design Alghero Italy

Cellular Automata (CA) have been introduced many decades ago as one of the most efficient parallel computational models able to simulate various physical processes and systems where the interactions are local. In this paper, we are trying to advance the application of CA in modeling wildfires by accounting for the fuzziness intrinsic to the numerous environmental variables and mechanisms engaged with the emergence of the phenomenon itself. The proposed Fuzzy CA (FCA) model adopts a data-driven approach, based on evolutionary optimization, which allows incorporating knowledge from real wildfires in order to enhance its accuracy. The main difficulty for doing so arrives from the computational complexity of the proposed framework and the burden of computational resources needed for its application, which would prevent the real-time prediction of fire spread scenarios. In order to tackle the aforementioned difficulties, we propose model's fully parallel implementations in Graphical Processing Units (GPUs) and Field Programmable Gate Arrays (FPGAs) hardware. In the article, we first investigate the speedup achieved by the developed parallel implementations. Then, we present and discuss two applications to heterogeneous landscapes through comparisons with observed wildfires. Moreover, we compare the proposed framework with two different modelling approaches and results found are really promising. (C) 2016 Elsevier B.V. All rights reserved.

关键词： Forest fire spreading Cellular automata Fuzzy theory GPU Hardware Parallelization

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Deriving architecture design variants for system optimization from design space descriptions expressed using a UML profile

Deriving architecture design variants for system optimizatio...

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2017 International Symposium on Model-driven Approaches for simulation Engineering, Mod4Sim 2017, Part of the 2017 Spring simulation Multi-conference, SpringSim 2017

作者： Wichmann, Alexander Bedini, Francesco Maschotta, Ralph Zimmermann, Armin Technische Universität Ilmenau Department of Computer Science and Automation System and Software Engineering Group PO-Box 100 565 Ilmenau98684 Germany

ISBN: (纸本)9781510838260

In complex (dynamic) systems, models are usually too complex for a direct evaluation, and simulation is the method of choice (indirect optimization). Another aspect is the structure of the design space for complex system. In a recent paper of the authors, an approach is presented for design space description with a UML profile-based description of architectural variations of complex dynamic systems. In order to execute a simulation of a system variant, one has to be chosen based on the used heuristic, and specified in a standardized way to be used for constructing the actual simulation model with the use of a library of template models. This paper approaches a method to automatically generated individual UML object models from the design space specification for a given parameter selection. ©2017 Society for modeling & simulation International (SCS).

关键词： Multiobjective optimization

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SIGSIM-PADS 2017 - Proceedings of the 2017 ACM SIGSIM conference on Principles of Advanced Discrete simulation

SIGSIM-PADS 2017 - Proceedings of the 2017 ACM SIGSIM Confer...

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5th ACM SIGSIM conference on Principles of Advanced Discrete simulation, SIGSIM-PADS 2017

ISBN: (纸本)9781450344890

The proceedings contain 25 papers. The topics discussed include: multi-tier priority queues and 2-tier ladder queue for managing pending events in sequential and optimistic parallel simulations;a conflict-resilient lock-free calendar queue for scalable share-everything PDES platforms;quantitative driven optimization of a time warp kernel;an integrated human decision making model under extended belief-desire-intention framework;exposing inter-process information for efficient parallel discrete event simulation of spatial stochastic systems;efficient parallel simulation over social contact network with skewed degree distribution;and Durango: scalable synthetic workload generation for extreme-scale application performance modeling and simulation.

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ACM International conference Proceeding Series

ACM International Conference Proceeding Series

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8th International Workshop on Equation-Based Object-Oriented modeling Languages and Tools, EOOLT 2017

ISBN: (纸本)9781450363730

The proceedings contain 13 papers. The topics discussed include: on the importance of scaling in equation-based modelling;collision handling with variable-step integrators;parallelizing simulations with runtime profiling and scheduling;equation-based modelling and simulation of hybrid systems;stochastic time Petri nets - time processes modelling in Modelica and application in hospital and healthcare;representations of equation-based models are not created equal;elaborate control: variable-structure modeling from an operational perspective;functional hybrid modelling towards mathematical physics;on the terminology and structuring of co-simulation methods;code generation for STM32F4 boards with Modelica device drivers;compile-time dynamic and recursive data structures in Modelica;towards an OpenModelica-based sensitivity analysis platform including optimization-driven strategies;and traceability and impact analysis in requirement verification.

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Size reduction of multi-band antennas using feature-based optimization

Size reduction of multi-band antennas using feature-based op...

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Loughborough Antennas and Propagation conference, LAPC 2017

作者： Koziel, S. Bekasiewicz, A. Engineering Optimization and Modeling Center Reykjavik University Reykjavik Iceland Faculty of Electronics Telecommunications and Informatics Gdansk University of Technology Gdansk Poland

ISBN: (纸本)9781785615153

Explicit size reduction of multi-band antennas using EM-driven design optimization is presented. The major challenge of multi-band antenna miniaturization is the necessity of independent control of frequency allocation and depths of several resonances while attempting to reduce physical dimensions of the structure at hand at the same time. In this work, we exploit feature-based optimization (FBO) framework which is well suited for handling multi-band antenna responses. The primary objective of the optimization process is the footprint area of the antenna, whereas design specifications imposed on reflection characteristics are handled by means of a penalty function approach. Owing to the general properties of FBO (i.e., "flattening" of the functional landscape) the design optimization costs can be kept at an acceptable levels of a few dozen of evaluation of the EM simulation model of the antenna. The proposed methodology is demonstrated using two structures, a dual-band patch antenna, and a triple-band dipole antenna. © 2017 Institution of Engineering and Technology. All rights reserved.

关键词： Dipole antennas

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The simulation of operating of a positioning system actuated by electrical stepping motor 8

The simulation of operating of a positioning system actuated...

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8th International conference on Manufacturing Science and Education (MSE) - Trends in New Industrial Revolution

作者： Rizescu, Dana Rizescu, Ciprian Ion Univ Politehn Bucuresti Mechatron & Precis Engn Dept 313 Splaiul Independentei Bucharest 060042 Romania

The work presents the current situation concerning positioning systems manufactured by well-known companies in the industry: Festo, SMC, etc, or patented solutions for positioning system. The authors suggest, following a thorough analysis, as a original solution, a positioning system driven by an electrical stepping motor. There are presented some particular elements of design, modeling, execution, testing and optimization of the proposed system. For validation, the mathematical model, authors have developed, in Matlab environment, a graphic user interface in which one can simulate the operation of several solutions with stepping motors, different positioning strokes.

关键词： Stepping motors

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