检索结果-内蒙古大学图书馆

arXiv 2021年

作者： Kwon, Woo Jin Del Pace, G. Xhani, K. Galantucci, L. Muzi Falconi, A. Inguscio, M. Scazza, F. Roati, G. Sesto Fiorentino50019 Italy Sesto Fiorentino50019 Italy Durham-Newcastle School of Mathematics Statistics and Physics Newcastle University Newcastle upon TyneNE1 7RU United Kingdom Department of Engineering Campus Bio-Medico University of Rome Rome00128 Italy

In quantum fluids, the quantisation of circulation forbids the diffusion of a vortex swirling flow seen in classical viscous fluids. Yet, a quantum vortex accelerating in a superfluid may lose its energy into acoustic radiation1,2, in a similar way an electric charge decelerates upon emitting photons. The dissipation of vortex energy underlies central problems in quantum hydrodynamics3, such as the decay of quantum turbulence, highly relevant to systems as varied as neutron stars, superfluid helium and atomic condensates4,5. A deep understanding of the elementary mechanisms behind irreversible vortex dynamics has been a goal for decades3,6, but it is complicated by the shortage of conclusive experimental signatures7,8. Here, we address this challenge by realising a programmable quantum vortex collider in a planar, homogeneous atomic Fermi superfluid with tunable inter-particle interactions. We create on-demand vortex configurations and monitor their evolution, taking advantage of the accessible time and length scales of our ultracold Fermi gas9,10. engineering collisions within and between vortex-antivortex pairs allows us to decouple relaxation of the vortex energy due to sound emission and interactions with normal fluid, i.e. mutual friction. We directly visualise how the annihilation of vortex dipoles radiates a sound pulse in the superfluid. Further, our few-vortex experiments extending across different superfluid regimes suggest that fermionic quasiparticles localised inside the vortex core contribute significantly to dissipation, opening the route to exploring new pathways for quantum turbulence decay, vortex by vortex. Copyright © 2021, The Authors. All rights reserved.

关键词： Vortex flow

来源：评论

学校读者我要写书评

暂无评论

Style Interleaved Learning for Generalizable Person Re-identification

arXiv

引用

arXiv 2022年

作者： Tan, Wentao Ding, Changxing Wang, Pengfei Gong, Mingming Jia, Kui The School of Future Technology South China University of Technology 381 Wushan Road Tianhe District Guangzhou510000 China The School of Electronic and Information Engineering South China University of Technology 381 Wushan Road TianheDistrict Guangzhou510000 China The Pazhou Lab Guangzhou510330 China The Department of Computing The Hong Kong Polytechnic University Hung Hom Hong Kong The School of Mathematics and Statistics The University of Melbourne MelbourneVIC3010 Australia

Domain generalization (DG) for person re-identification (ReID) is a challenging problem, as access to target domain data is not permitted during the training process. Most existing DG ReID methods update the feature extractor and classifier parameters based on the same features. This common practice causes the model to overfit to existing feature styles in the source domain, resulting in sub-optimal generalization ability on target domains. To solve this problem, we propose a novel style interleaved learning (IL) framework. Unlike conventional learning strategies, IL incorporates two forward propagations and one backward propagation for each iteration. We employ the features of interleaved styles to update the feature extractor and classifiers using different forward propagations, which helps to prevent the model from overfitting to certain domain styles. To generate interleaved feature styles, we further propose a new feature stylization approach. It produces a wide range of meaningful styles that are both different and independent from the original styles in the source domain, which caters to the IL methodology. Extensive experimental results show that our model not only consistently outperforms state-of-the-art methods on large-scale benchmarks for DG ReID, but also has clear advantages in computational efficiency. The code is available at https://***/WentaoTan/Interleaved-Learning. Copyright © 2022, The Authors. All rights reserved.

关键词： Computational efficiency

来源：评论

学校读者我要写书评

暂无评论

A Consensus Privacy Metrics Framework for Synthetic Data

arXiv

引用

arXiv 2025年

作者： Pilgram, Lisa Dankar, Fida K. Drechsler, Jörg Elliot, Mark Domingo-Ferrer, Josep Francis, Paul Kantarcioglu, Murat Kong, Linglong Malin, Bradley Muralidhar, Krishnamurty Myles, Puja Prasser, Fabian Raisaro, Jean Louis Yan, Chao El Emam, Khaled School of Epidemiology and Public Health University of Ottawa ON Canada CHEO Research Institute ON Canada Department of Nephrology and Medical Intensive Care Charité – Universitätsmedizin Berlin Berlin Germany Department for Statistical Methods Institute for Employment Research Nuernberg Germany Institute for Statistics Ludwig-Maximilians-Universität Munich Germany Joint Program in Survey Methodology University of Maryland United States The Cathie Marsh Institute Research School of Social Sciences University of Manchester Manchester United Kingdom Department of Computer Engineering and Mathematics Universitat Rovira i Virgili Catalonia Tarragona Spain Max Planck Institute for Software Systems Germany Department of Computer Science Virginia Tech United States Department of Mathematical and Statistical Sciences University of Alberta Alberta Canada Department of Biomedical Informatics Vanderbilt University Medical Center NashvilleTN United States Department of Biostatistics Vanderbilt University Medical Center NashvilleTN United States Department of Computer Science Vanderbilt University NashvilleTN United States Department of Marketing and Supply Chain Management University of Oklahoma Oklahoma United States Medicines and Healthcare products Regulatory Agency London United Kingdom Berlin Institute of Health at Charité Universitätsmedizin Berlin Medical Informatics Group Berlin Germany Biomedical Data Science Center University Hospital Lausanne Lausanne Switzerland

Synthetic data generation is one approach for sharing individual-level data. However, to meet legislative requirements, it is necessary to demonstrate that the individuals’ privacy is adequately protected. There is no consolidated standard for measuring privacy in synthetic data. Through an expert panel and consensus process, we developed a framework for evaluating privacy in synthetic data. Our findings indicate that current similarity metrics fail to measure identity disclosure, and their use is discouraged. For differentially private synthetic data, a privacy budget other than close to zero was not considered interpretable. There was consensus on the importance of membership and attribute disclosure, both of which involve inferring personal information about an individual without necessarily revealing their identity. The resultant framework provides precise recommendations for metrics that address these types of disclosures effectively. Our findings further present specific opportunities for future research that can help with widespread adoption of synthetic data. © 2025, CC BY.

关键词： Differential privacy

来源：评论

学校读者我要写书评

暂无评论

SPACE: 3D parallel solvers for Vlasov-Maxwell and Vlasov-Poisson equations for relativistic plasmas with atomic transformations

arXiv

引用

arXiv 2021年

作者： Yu, Kwangmin Kumar, Prabhat Yuan, Shaohua Cheng, Aiqi Samulyak, Roman Computational Science Initiative Brookhaven National Laboratory UptonNY11973 United States Center for Computational Sciences and Engineering Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Applied Mathematics and Statistics Stony Brook University Stony BrookNY11794 United States

A parallel, relativistic, three-dimensional particle-in-cell code SPACE has been developed for the simulation of electromagnetic fields, relativistic particle beams, and plasmas. In addition to the standard second-order Particle-in-Cell (PIC) algorithm, SPACE includes efficient novel algorithms to resolve atomic physics processes such as multi-level ionization of plasma atoms, recombination, and electron attachment to dopants in dense neutral gases. SPACE also contains a highly adaptive particle-based method, called Adaptive Particle-in-Cloud (AP-Cloud), for solving the Vlasov-Poisson problems. It eliminates the traditional Cartesian mesh of PIC and replaces it with an adaptive octree data structure. The code’s algorithms, structure, capabilities, parallelization strategy and performances have been discussed. Typical examples of SPACE applications to accelerator science and engineering problems are also *** Codes I.6, D.2 © 2021, CC BY.

关键词： Beam plasma interactions

来源：评论

学校读者我要写书评

暂无评论

Influence of Initial Residual Stress on Growth and Pattern Creation for a Layered Aorta

arXiv

引用

arXiv 2020年

作者： Du, Yangkun Lü, Chaofeng Destrade, Michel Chen, Weiqiu Department of Engineering Mechanics Zhejiang University Hangzhou China Department of Civil Engineering Zhejiang University Hangzhou310058 China Soft Matter Research Center Zhejiang University Hangzhou310027 China Key Lab of Soft Machines and Smart Devices of Zhejiang Province Zhejiang University Hangzhou China Stokes Centre for Applied Mathematics School of Mathematics Statistics and Applied Mathematics NUI Galway Galway Ireland

Residual stress is ubiquitous and indispensable in most biological and artificial materials, where it sustains and optimizes many biological and functional mechanisms. The theory of volume growth, starting from a stress-free initial state, is widely used to explain the creation and evolution of growth-induced residual stress and the resulting changes in shape, and to model how growing bio-tissues such as arteries and solid tumors develop a strategy of pattern creation according to geometrical and material *** modelling provides promising avenues for designing and directing some appropriate morphology of a given tissue or organ and achieve some targeted biomedical function. In this paper, we rely on a modified, augmented theory to reveal how we can obtain growth-induced residual stress and pattern evolution of a layered artery by starting from an existing, non-zero initial residual stress state. We use experimentally determined residual stress distributions of aged bi-layered human aortas and quantify their influence by a magnitude factor. Our results show that initial residual stress has a more significant impact on residual stress accumulation and the subsequent evolution of patterns than geometry and material ***, we provide an essential explanation for growth-induced patterns driven by differential growth coupled to an initial residual stress. Finally, we show that initial residual stress is a readily available way to control growth-induced pattern creation for tissues and thus may provide a promising inspiration for biomedical engineering. Copyright © 2020, The Authors. All rights reserved.

关键词： Residual stresses

来源：评论

学校读者我要写书评

暂无评论

Optical fiber coupler analysis using daubechies wavelets

引用

Journal of Microwaves, Optoelectronics and Electromagnetic Applications 2020年第3期19卷 294-300页

作者： Da Silva, P.C.L. De Melo, R.R. Da Silva, J.P. Department of Natural Sciences Mathematics and Statistics Federal Rural University of the Semi-Arid Mossoró Brazil Federal University of Ceará Sobral Brazil Department of Electrical Engineering Federal University of Rio Grande do Norte Natal Brazil

This article presents the theoretical analysis of a signal coupling between a proposed Photonic Crystal Fiber (PCF) and a Conventional Fiber with Step Index (CFSI) system. In this analysis, the Finite Element Method (FEM) and Beam Propagation Method (BPM) are applied together with Daubechies wavelets as basis function and described in the mathematical formulation. The simulations were performed casting the PCF signal into CFSI core using the PCF refractive index. For simulation purposes, the cladding material refractive index was set as 1.5% lower than the core index. The application of Daubechies wavelets as basis functions in BPM analysis presented insertion loss around 3.8% during the fiber coupling. © 2020 SBMO/SBMag.

关键词： Photonic crystal fibers

来源：评论

学校读者我要写书评

暂无评论

Comparison and Estimation of Four Infiltration Models

引用

Open Journal of Soil Science 2020年第2期10卷 45-57页

作者： Atta-Darkwa Thomas Antwi Eric Ofosu Amankwah Emmanuel Ankamah Johnson De-Graft Akolgo Gilbert Ayine Austin Asare Antwi Alexander Department of Mechanical and Manufacturing Engineering University of Energy and Natural Resources Sunyani Ghana Department of Energy and Environmental Engineering University of Energy and Natural Resources Sunyani Ghana Department of Mathematics and Statistics University of Energy and Natural Resources Sunyani Ghana Department of Environmental Management University of Energy and Natural Resources Sunyani Ghana

Infiltration is an important component of the hydrological cycle. It provides soil moisture in the vadose zone to support plant growth. This study was conducted to compare the validity of four infiltration models with measured values from the double ring infiltrometer. The parameters of the four models compared were estimated using the linear regression analysis. The C.C was used to show the performance of the predictability of the models. The RMSE, MAE and MBE were employed to check the anomalies between the predicted and the observed values. The results showed that, average values of the C.C ranged from 0.9294 - 0.9852. The average values of the RMSE were 4.0033, −17.489, 11.2400 and 49.8448;MAE were 3.1341, 15.9802, 10.6525, and 61.4736;and MBE were 0.0786, 9.5755, 0.0007 and 47.0204 for Philip, Horton, Green Ampt and Kostiakov respectively for the wetland soils. Statistical results also from the Fisher’s multiple comparison test show that the mean infiltration rate estimated from the Green Ampt’s, Philip’s and Horton’s model was not significantly different (p > 0.05) from the observed. The results indicated that the Kostiakov’s model had the highest deviations as it overestimated the measured data in all the plots. Comparison of the statistical parameters C.C, RMSE, MAE, and MBE for the four models indicates that the Philip’s model agreed well with the measured data and therefore, performed better than the Green Ampt’s, Horton’s and Kostiakov’s models respectively in that order for Besease wetland soils. Estimation of infiltration rate by the Philip’s model is important in the design of irrigation schemes and scheduling. Therefore, in the absence of measured infiltration data, the Philip’s model could be used to produce infiltration information for inland valley bottom soils that exhibit similar characteristic as Besease wetland soils.

关键词： Wetland Infiltration Models Irrigation Philip’s Model Ring Infiltrometer

来源：评论

学校读者我要写书评

暂无评论

Speeding Up Quantum Measurement Using Space-Time Trade-Off

引用

Physical Review Letters 2025年第8期134卷 080801-080801页

作者： Christopher Corlett Ieva Čepaitė Andrew J. Daley Cica Gustiani Gerard Pelegrí Jonathan D. Pritchard Noah Linden Paul Skrzypczyk Quantum Engineering Centre for Doctoral Training University of Bristol Tyndall Avenue Bristol BS8 1FD United Kingdom H.H. Wills Physics Laboratory University of Bristol Tyndall Avenue Bristol BS8 1TL United Kingdom Department of Physics and SUPA University of Strathclyde Glasgow G4 0NQ United Kingdom Clarendon Laboratory University of Oxford Parks Road Oxford OX1 3PU United Kingdom LIP6 CNRS Sorbonne Université 4 Place Jussieu 75005 Paris France School of Mathematics University of Bristol Fry Building Woodland Road Bristol BS8 1UG United Kingdom CIFAR Azrieli Global Scholars Program CIFAR Toronto Canada

We present a scheme for speeding up quantum measurement. The scheme builds on previous protocols that entangle the system to be measured with ancillary systems. In the idealized situation of perfect entangling operations and no decoherence, it gives an exact space-time trade-off meaning the readout speed increases linearly with the number of ancilla. We verify this scheme is robust against experimental imperfections through numerical modeling of gate noise and readout errors, and under certain circumstances our scheme can even lead to better than linear improvement in the speed of measurement with the number of systems measured. This hardware-agnostic approach is broadly applicable to a range of quantum technology platforms and offers a route to accelerate midcircuit measurement as required for effective quantum error correction.

关键词： Quantum entanglement

来源：评论

学校读者我要写书评

暂无评论

Generalization Limits of Graph Neural Networks in Identity Effects Learning

arXiv

引用

arXiv 2023年

作者： D'Inverno, Giuseppe Alessio Brugiapaglia, Simone Ravanelli, Mirco DIISM - University of Siena via Roma 56 Siena53100 Italy Department of Mathematics and Statistics Concordia University 1400 De Maisonneuve Blvd. W. MontréalQCH3G 1M8 Canada Department of Computer Science and Software Engineering Concordia University 2155 Guy St. MontréalQCH3H 2L9 Canada Mila - Quebec AI Institute 6666 Saint-Urbain R. MontréalQCH2S 3H1 Canada

Graph Neural Networks (GNNs) have emerged as a powerful tool for data-driven learning on various graph domains. They are usually based on a message-passing mechanism and have gained increasing popularity for their intuitive formulation, which is closely linked to the Weisfeiler-Lehman (WL) test for graph isomorphism to which they have been proven equivalent in terms of expressive power. In this work, we establish new generalization properties and fundamental limits of GNNs in the context of learning so-called identity effects, i.e., the task of determining whether an object is composed of two identical components or not. Our study is motivated by the need to understand the capabilities of GNNs when performing simple cognitive tasks, with potential applications in computational linguistics and chemistry. We analyze two case studies: (i) two-letters words, for which we show that GNNs trained via stochastic gradient descent are unable to generalize to unseen letters when utilizing orthogonal encodings like one-hot representations;(ii) dicyclic graphs, i.e., graphs composed of two cycles, for which we present positive existence results leveraging the connection between GNNs and the WL test. Our theoretical analysis is supported by an extensive numerical study. Copyright © 2023, The Authors. All rights reserved.

关键词： Graph neural networks

来源：评论

学校读者我要写书评

暂无评论

Best practices for estimating and reporting epidemiological delay distributions of infectious diseases using public health surveillance and healthcare data

arXiv

引用

arXiv 2024年

作者： Charniga, Kelly Park, Sang Woo Akhmetzhanov, Andrei R. Cori, Anne Dushoff, Jonathan Funk, Sebastian Gostic, Katelyn M. Linton, Natalie M. Lison, Adrian Overton, Christopher E. Pulliam, Juliet R.C. Ward, Thomas Cauchemez, Simon Abbott, Sam Mathematical Modelling of Infectious Diseases Unit Institut Pasteur Université Paris Cité CNRS UMR 2000 Paris France Department of Ecology and Evolutionary Biology Princeton University PrincetonNJ United States College of Public Health National Taiwan University Taipei Taiwan MRC Centre for Global Infectious Disease Analysis School of Public Health Imperial College London London United Kingdom Departments of Mathematics & Statistics and Biology McMaster University HamiltonON Canada Department of Biology McMaster University HamiltonON Canada M. G. DeGroote Institute for Infectious Disease Research McMaster University HamiltonON Canada Department of Infectious Disease Epidemiology and Dynamics London School of Hygiene & Tropical Medicine London United Kingdom Centre for Mathematical Modelling of Infectious Diseases London School of Hygiene & Tropical Medicine London United Kingdom Center for Forecasting and Outbreak Analytics U.S. Centers for Disease Control and Prevention AtlantaGA United States Graduate School of Medicine Hokkaido University Sapporo-shi Hokkaido Japan Department of Biosystems Science and Engineering ETH Zurich Zurich Switzerland Department of Mathematical Sciences University of Liverpool Liverpool United Kingdom All Hazards Intelligence Infectious Disease Modelling Team Data Analytics and Surveillance UK Health Security Agency United Kingdom Department of Mathematics University of Manchester Manchester United Kingdom

Epidemiological delays, such as incubation periods, serial intervals, and hospital lengths of stay, are among key quantities in infectious disease epidemiology that inform public health policy and clinical practice. This information is used to inform mathematical and statistical models, which in turn can inform control strategies. There are three main challenges that make delay distributions difficult to estimate. First, the data are commonly censored (e.g., symptom onset may only be reported by date instead of the exact time of day). Second, delays are often right truncated when being estimated in real time (not all events that have occurred have been observed yet). Third, during a rapidly growing or declining outbreak, overrepresentation or underrepresentation, respectively, of recently infected cases in the data can lead to bias in estimates. Studies that estimate delays rarely address all these factors and sometimes report several estimates using different combinations of adjustments, which can lead to conflicting answers and confusion about which estimates are most accurate. In this work, we formulate a checklist of best practices for estimating and reporting epidemiological delays with a focus on the incubation period and serial interval. We also propose strategies for handling common biases and identify areas where more work is needed. Our recommendations can help improve the robustness and utility of reported estimates and provide guidance for the evaluation of estimates for downstream use in transmission models or other analyses. Copyright © 2024, The Authors. All rights reserved.

关键词： Diseases

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：