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arXiv 2025年

作者： Pawusch, Louisa Scheurer, Stefania Nowak, Wolfgang Maxwell, Reed University of Stuttgart Institute for Modeling Hydraulic and Environmental Systems Stuttgart Center for Simulation Science Stuttgart Germany Princeton University Dept. of Civil and Environmental Engineering PrincetonNJ United States Princeton University Dept. of Civil and Environmental Engineering High Meadows Environmental Institute Integrated GroundWater Modeling Center PrincetonNJ United States

Finding the initial depth-to-water table (DTWT) configuration of a catchment is a critical challenge when simulating the hydrological cycle with integrated models, significantly impacting simulation outcomes. Traditionally, this involves iterative spin-up computations, where the model runs under constant atmospheric settings until steady-state is achieved. These so-called model spin-ups are computationally expensive, often requiring many years of simulated time, particularly when the initial DTWT configuration is far from steady state. To accelerate the model spin-up process we developed HydroStartML, a machine learning emulator trained on steady-state DTWT configurations across the contiguous United States. HydroStartML predicts, based on available data like conductivity and surface slopes, a DTWT configuration of the respective watershed, which can be used as an initial DTWT. Our results show that initializing spin-up computations with HydroStartML predictions leads to faster convergence than with other initial configurations like spatially constant DTWTs. The emulator accurately predicts configurations close to steady state, even for terrain configurations not seen in training, and allows especially significant reductions in computational spin-up effort in regions with deep DTWTs. This work opens the door for hybrid approaches that blend machine learning and traditional simulation, enhancing predictive accuracy and efficiency in hydrology for improving water resource management and understanding complex environmental interactions. © 2025, CC BY-NC-ND.

关键词： Water management

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A credible mechanism of service about data resource in cloud computing

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International Journal of Network Security 2018年第4期20卷 754-761页

作者： Li, Yunfa Shen, Yangyang Li, Mingyi Key Laboratory of Complex Systems Modeling and Simulation School of Computer Hangzhou Dianzi University Xiasha Higher Education Zone Hangzhou Zhejiang Province310018 China

In order to protect the security of service in cloud computing, we propose a credible mechanism of service for data resource. In the mechanism, we first build a system model and put forward its implementation process. Then, we design an encryption method used in the system model. On this basis, we discuss the function of the third party trusted platform. All of these constitute a credible mechanism of service about data resource in cloud computing. In order to verify the feasibility of the mechanism, a series of experiments have been done. The experimental results show that it is feasible to ensure the security of service about data resource in cloud computing. © 2018, Femto Technique Co., Ltd.

关键词： Cryptography

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DEM simulation of particle percolation in a packed bed

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Particuology 2008年第6期6卷 475-482页

作者： Mahbubur Rahman Haiping Zhu Aibing Yu John Bridgwater Lab for Simulation and Modeling of Particulate Systems School of Materials Science and Engineering The University of New South Wales Sydney NSW 2052 Australia Department of Chemical Engineering University of Cambridge Cambridge CB2 3RA UK

The phenomenon of spontaneous particle percolation under gravity is investigated by means of the discrete element method. Percolation behaviors such as percolation velocity, residence time distribution and radial dispersion are examined under various conditions. It is shown that the vertical velocity of a percolating particle moving down through a packing of larger particles decreases with increasing the restitution coefficient between particles and diameter ratio of the percolating to packing particles. With the increase of the restitution coefficient, the residence time and radial dispersion of the percolating particles increase. The packing height affects the residence time and radial dispersion. But, the effect can be eliminated in the analysis of the residence time and radial dispersion when they are normalized by the average residence time and the product of the packing height and packing particle diameter, respectively. In addition, the percolation velocity is shown to be related to the vertical acceleration of the percolating particle when an extra constant vertical force is applied. Increasing the feeding rate of percolating particles decreases the dispersion coefficient.

关键词： Discrete element method Particle percolation Residence time Radial dispersion

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Relationship graph learning network for visual relationship detection 2

Relationship graph learning network for visual relationship ...

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2nd ACM International Conference on Multimedia in Asia, MMAsia 2020

作者： Li, Yanan Yu, Jun Zhan, Yibing Chen, Zhi Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China

ISBN: (纸本)9781450383080

Visual relationship detection aims to predict the relationships between detected object pairs. It is well believed that the correlations between image components (i.e., objects and relationships between objects) are significant considerations when predicting objects' relationships. However, most current visual relationship detection methods only exploited the correlations among objects, and the correlations among objects' relationships remained underexplored. This paper proposes a relationship graph learning network (RGLN) to explore the correlations among objects' relationships for visual relationship detection. Specifically, RGLN obtains image objects using an object detector, and then, every pair of objects constitutes a relationship proposal. All relationship proposals construct a relationship graph, in which the proposals are treated as nodes. Accordingly, RGLN designs bi-stream graph attention subnetworks to detect relationship proposals, in which one graph attention subnetwork analyzes correlations among relationships based on visual and spatial information, and the other analyzes correlations based on semantic and spatial information. Besides, RGLN exploits a relationship selection subnetwork to ignore redundant information of object pairs with no relationships. We conduct extensive experiments on two public datasets: the VRD and the VG datasets. The experimental results compared with the state-of-the-art demonstrate the competitiveness of RGLN. © 2021 ACM.

关键词： Semantics

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Net-centric information sharing for M&S

Net-centric information sharing for M&S

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simulation Interoperability Workshop Fall 2008

作者： Broyles, David H. Moore, John S. Spawar Systems Center Navy Modeling and Simulation Office Space and Naval Warfare Systems Center Atlantic 1 Innovation Drive Hanahan SC 29406 United States Navy Modeling and Simulation Office 1333 Isaac Hull Ave SE Washington DC United States

ISBN: (纸本)9781605604183

Building modeling and simulation (M&S) tools, whose data is visible and accessible because each piece of data is described in accordance with the DoD Discovery Metadata Specification (DDMS), is a goal necessary to meet the net-centric information sharing requirements of the global information grid (GIG). DoD has been working on the fundamental standards required to start this transformation for years and has finally reached the "opening kickoff" to realizing the GIG environment. This effort began over a decade ago with the DoD Services creating a common set of descriptions for the fields in their M&S resource repositories/registries (MSRR). What was then "just good database management" became the starting point for developing the M&S extension to the DDMS. This extension is presented in detail by Roy Scrudder at this Workshop and is included here to present a complete picture. This paper reports on the status of enabling, per the DDMS, the initial set of tools and services which include the M&S Catalogs, the DoD Standards Vetting Tool (SVT), the DoD Verification, Validation and Accreditation Documentation Tool (VDT), the navy Capabilities and Requirements Tool (NCRT) and the M&S extension to the DDMS. The specification extension is already approved. The other tools and services - the focus for this paper - will be released in their initial configuration by the end of September 08. The M&S Catalog will serve as a registry during the transition and testing of new transitions, data types, metadata specification changes, etc. Once ready, the approved metadata will transfer to DoD's Metadata Registry (MDR). By using precise metadata, "holdings" in centralized repositories are no longer required to allow accessibility. By using DDMS compliant metadata, it does not matter where the "holdings" are physically located. This will require users and suppliers of data to rethink how data is stored and retrieved and hopefully enable more efficient and effective methods than curren

关键词： Metadata

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Autonomous Decision Making with Reinforcement Learning in Multi-UAV Air Combat

Autonomous Decision Making with Reinforcement Learning in Mu...

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2023 IEEE International Conference on systems, Man, and Cybernetics, SMC 2023

作者： Feng, Xutao Ma, Yaofei Zhao, Liping Yang, Hanbo Beihang University School of Automation Science and Electrical Engineering Beijing China Beijing Simulation Center National Key Laboratory of Modeling and Simulation for Complex Systems Beijing China

ISBN: (纸本)9798350337020

A multi-agent decision network based on QMIX is proposed in this paper to cope with the coordination decision problem of multiple UAV air combat missions. To speed up the training process, three improvements are introduced: 1) An improved ϵ-decaying method that enable some tutor to help in action selection at the early stage of the training. This measure greatly improves the exploring efficiency when the network are far from being fully trained;2) State pruning and action mask measures are applied during the training. The former improves the effectiveness of the input state information, and the latter reduces unnecessary action exploring. 3) A gradually training configuration is used to make the training process more robust, where the combat adversaries are configured as the static targets, the randomly maneuver vehicles, and the Min-Max strategy vehicles respectively. The multi-UAV air combat scenarios are built up and the experiments are conducted. The results shows that these improvements have significantly improved training efficiency. © 2023 IEEE.

关键词： Action Mask Air combat MARL Min-Max strategy Quadrotor UAV

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Monitoring a maximum power point tracking photovoltaic pumping system 9

Monitoring a maximum power point tracking photovoltaic pumpi...

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9th International Renewable Energy Congress, IREC 2018

作者： Ehssein, Chighali Ould Ba, Abdellahi Dah, Ne Ould Lam, Mamadou Ibrahima Amadou, Diakite Hassan, Aroudam El Rosso Mauritania Modeling and Simulation of Mechanical Systems Laboratory Faculty of Sciences University Abdelmalek Essaadi Tétouan Morocco

ISBN: (纸本)9781538609989

This study presents a monitored standalone photovoltaic solar direct pumping system using the Maximum Power Point Tracking (MPPT) algorithm to optimize the solar photovoltaic conversion efficiency. It was done at ISET-Rosso in Mauritania. The experimental setup based on Lorentz PS1200C-SJ5-8 pumping system consists of four photovoltaic (PV) panels, inverter PS1200, BLDC motor, centrifugal pump and a storage tank. The system has been monitored, in order to determine the relationship between: the DC power produced by the PV generator and the solar radiation;the water flow and the DC power and by then the relationship between the water flow and the solar radiation. © 2018 IEEE.

关键词： Solar radiation

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Dynamic directed functional connectivity as a neural biomarker for objective motor skill assessment

arXiv

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arXiv 2025年

作者： Kamat, Anil Rahul, Rahul Dutta, Anirban Cavuoto, Lora Kruger, Uwe Burke, Harry Hackett, Matthew Norfleet, Jack Schwaitzberg, Steven De, Suvranu Center for Modeling Simulation and Imaging for Medicine Rensselaer Polytechnic Institute TroyNY12180 United States Department of Industrial and Systems Engineering University at Buffalo BuffaloNY United States Department of Surgery University at Buffalo Jacobs School of Medicine and Biomedical Sciences BuffaloNY United States Department of Medicine F. Edward Hébert School of Medicine Uniformed Services University of the Health Sciences BethesdaMD United States U.S. Army Futures Command Combat Capabilities Development Command Soldier Center STTC OrlandoFL United States Centre for Systems Modelling and Quantitative Biomedicine University of Birmingham United Kingdom College of Engineering Florida A&M University-Florida State University TallahasseeFL32310 United States

Objective motor skill assessment plays a critical role in fields such as surgery, where proficiency is vital for certification and patient safety. Existing assessment methods, however, rely heavily on subjective human judgment, which introduces bias and limits reproducibility. While recent efforts have leveraged kinematic data and neural imaging to provide more objective evaluations, these approaches often overlook the dynamic neural mechanisms that differentiate expert and novice performance. This study proposes a novel method for motor skill assessment based on dynamic directed functional connectivity (dFC) as a neural biomarker. By using electroencephalography (EEG) to capture brain dynamics and employing an attention-based Long Short-Term Memory (LSTM) model for nonlinear Granger causality analysis, we compute dFC among key brain regions involved in psychomotor tasks. Coupled with hierarchical task analysis (HTA), our approach enables subtask-level evaluation of motor skills, offering detailed insights into neural coordination that underpins expert proficiency. A convolutional neural network (CNN) is then used to classify skill levels, achieving greater accuracy and specificity than established performance metrics in laparoscopic surgery. This methodology provides a reliable, objective framework for assessing motor skills, contributing to the development of tailored training protocols and enhancing the certification process. © 2025, CC BY.

关键词： Electroencephalography

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Design and implementation for a non linear state filter for LEO micro satellite

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Journal of Applied Sciences 2009年第24期9卷 4195-4205页

作者： Chouraqui, S. Benyettou, M. Simulation and Modeling of Industrial Systems Laboratory Department of Computer Science Faculty of Science University of Science and Technology of Oran P.O.Box BP 1505 EI-Menaour Oran Algeria

This study preliminarily investigates the numerical application of both Extended Kalman Filter (EKF) (which has traditionally been used for non linear estimation) and a relatively new filter, Unscented Kalman Filter (UKF) to the nonlinear estimation problem. The new method can be applied to nonlinear systems without the linearization process necessary for the EKF and it does not demand a Gaussian distribution of noise and what's more, its ease of implementation and more accurate estimation features enables it to demonstrate its good performance. Present experimental results and analysis indicate that unscented Kalman filtering UKF have shown better performances in presence of the severe nonlinearity in state equations. © 2009 Asian Network for Scientific Information.

关键词： Extended Kalman filters

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Optimization of a Standalone PV System with a New Proposed MPPT Method 11

Optimization of a Standalone PV System with a New Proposed M...

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11th International Renewable Energy Congress, IREC 2020

作者： Ba, Abdellahi Ehssein, Chighali Benkaddour, Assia Hassan, Aroudam El Rosso Mauritania University Abdelmalek Essaadi Modeling and Simulation of Mechanical Systems Laboratory Faculty of Sciences Tétouan Morocco

ISBN: (纸本)9781728155722

To achieve better optimization of the productivity of a standalone photovoltaic solar system, we first need to characterize the climate of the area where the system will be implemented. Then we have to study the behavior of the chosen charge with respect to the characteristics of the electrical parameters delivered by the photovoltaic generator (PVG). This will allow us to choose the right DC/DC converter. The new proposed MPPT method is based on the prediction of the maximum power point (MPP) of the PVG from the measurement of irradiation and temperature. The relationship between the MPP and the measured irradiation and temperature are modeled via mathematical equations by numerical methods such as interpolations (digital arithmetic sequence). Four parameters are created to facilitate the system controllability through the voltages of the inputs and outputs of the DC/DC converter with the climatic parameters variation. To test and evaluate the performance of the proposed MPPT method, we will make comparisons with conventional methods, such as: Perturb and Observe (PO), Incremental Conductance (INC) and Fractional Open Circuit Voltage (FOCV), under dynamic weather conditions. © 2020 IEEE.

关键词： DC-DC converters

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