检索结果-内蒙古大学图书馆

Review of e-learning service framework based on cloud computing

学校读者我要写书评

暂无评论

AIP Conference Proceedings 2023年第1期2706卷

作者： Purwono Hendradi Moh Khanapi Abd Ghani Siti Nur Mahfuzah Mohamad Karima Aissaoui Uky Yudatama Teknik Informatika Universitas Muhammadiyah Magelang Magelang Indonesia Biomedical Computing and Engineering Technologies (BIOCORE) Applied Research Group Faculty of Information and Communication Technology Universiti Teknikal Malaysia Melaka Melaka Malaysia Department of Interactive Media Faculty of Information and Communication Technology Universiti Teknikal Malaysia Melaka Melaka Malaysia Artificial Intelligence Data Science and Emergent Systems Laboratory ENSAF Sidi Mohammed Ben Abdellah University FEZ Morocco

The impact of Covid-19 on education is the result of online learning from home as part of the Work from Home (WFH) protocol. There are at least three essential roles in WFH, namely Institutions, Teachers and Students, each of which uses personal resources. This literature begins with a review of the primary literature with the theme of e-learning frameworks and cloud computing. It is found that two crucial things are Integration and measuring the level of success. On that basis, in this literature review research, keywords are taken from the theme, including the word equation by using AND OR operators on the research database site over a span of the last five years. Each literature will be explored in stages focusing on the problem of Integration and or Measurement Level measurement. These results become material for systematic discussion so that an overview is obtained for the development of an E-learning Service Framework based on Cloud computing using a six-layer model with the Business Process layer being the layer used in system integration, both with other service systems and similar systems in the education ecosystem.

关键词：

A data-driven approach for discovering stochastic dynamical systems with non-Gaussian Lévy noise

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Li, Yang Duan, Jinqiao State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics 29 Yudao Street Nanjing210016 China Department of Applied Mathematics College of Computing Illinois Institute of Technology ChicagoIL60616 United States

With the rapid increase of valuable observational, experimental and simulating data for complex systems, great efforts are being devoted to discovering governing laws underlying the evolution of these systems. However, the existing techniques are limited to extract governing laws from data as either deterministic differential equations or stochastic differential equations with Gaussian noise. In the present work, we develop a new data-driven approach to extract stochastic dynamical systems with non-Gaussian symmetric Lévy noise, as well as Gaussian noise. First, we establish a feasible theoretical framework, by expressing the drift coefficient, diffusion coefficient and jump measure (i.e., anomalous diffusion) for the underlying stochastic dynamical system in terms of sample paths data. We then design a numerical algorithm to compute the drift, diffusion coefficient and jump measure, and thus extract a governing stochastic differential equation with Gaussian and non-Gaussian noise. Finally, we demonstrate the efficacy and accuracy of our approach by applying to several prototypical one-, two- and three-dimensional systems. This new approach will become a tool in discovering governing dynamical laws from noisy data sets, from observing or simulating complex phenomena, such as rare events triggered by random fluctuations with heavy as well as light tail statistical features. Copyright © 2020, The Authors. All rights reserved.

关键词： Gaussian noise (electronic)

A local character based method for solving linear systems of radiation diffusion problemsI

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Ye, Shuai An, Hengbin Xu, Xinhai State Key Laboratory of High Performance Computing National University of Defense Technology Changsha410073 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing100094 China CAEP Software Center for High Performance Numerical Simulation Beijing100088 China Artificial Intelligence Research Center National Innovation Institute of Defense Technology Beijing100071 China

The radiation diffusion problem is a kind of time-dependent nonlinear equations. For solving the radiation diffusion equations, many linear systems are obtained in the nonlinear iterations at each time step. The cost of linear equations dominates the numerical simulation of radiation diffusion applications, such as inertial confinement fusion, etc. Usually, iterative methods are used to solve the linear systems in a real application. Moreover, the solution of the previous nonlinear iteration or the solution of the previous time step is typically used as the initial guess for solving the current linear equations. Because of the strong local character in ICF, with the advancing of nonlinear iteration and time step, the solution of the linear system changes dramatically in some local domain, and changes mildly or even has no change in the rest domain. In this paper, a local character-based method is proposed to solve the linear systems of radiation diffusion problems. The proposed method consists of three steps: Firstly, a local domain (algebraic domain) is constructed;secondly, the subsystem on the local domain is solved;and lastly, the whole system will be solved. Two methods are given to construct the local domain. One is based on the spatial gradient, and the other is based on the residual. Numerical tests for a two-dimensional heat conduction model problem, and two real application models, the multi-group radiation diffusion equations and the three temperature energy equations, are conducted. The test results show that the solution time for solving the linear system can be reduced dramatically by using the local character-based method. Copyright © 2020, The Authors. All rights reserved.

关键词： Linear systems

Crystalline phase discriminating neutron tomography using advanced reconstruction methods

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Ametova, Evelina Burca, Genoveva Chilingaryan, Suren Fardell, Gemma Jørgensen, Jakob S. Papoutsellis, Evangelos Pasca, Edoardo Warr, Ryan Turner, Martin Lionheart, William R.B. Withers, Philip J. Henry Royce Institute Department of Materials The University of Manchester M13 9PL United Kingdom Laboratory for Application of Synchrotron Radiation Karlsruhe Institute of Technology Germany ISIS Pulsed Neutron and Muon Source STFC UKRI Rutherford Appleton Laboratory United Kingdom Department of Mathematics The University of Manchester M13 9PL United Kingdom Institute for Data Processing and Electronics Karlsruhe Institute of Technology Germany Scientific Computing Department STFC UKRI Rutherford Appleton Laboratory United Kingdom Department of Applied Mathematics and Computer Science Technical University of Denmark Denmark Research IT Services The University of Manchester M13 9PL United Kingdom

Time-of-flight neutron imaging offers complementary attenuation contrast to X-ray computed tomography (CT), coupled with the ability to extract additional information from the variation in attenuation as a function of neutron energy (time of flight) at every point (voxel) in the image. In particular Bragg edge positions provide crystallographic information and therefore enable the identification of crystalline phases directly. Here we demonstrate Bragg edge tomography with high spatial and spectral resolution. We propose a new iterative tomographic reconstruction method with a tailored regularisation term to achieve high quality reconstruction from low-count data, where conventional filtered back-projection (FBP) fails. The regularisation acts in a separated mode for spatial and spectral dimensions and favours characteristic piece-wise constant and piecewise smooth behaviour in the respective dimensions. The proposed method is compared against FBP and a state-of-the-art regulariser for multi-channel tomography on a multi-material phantom. The proposed new regulariser which accommodates specific image properties outperforms both conventional and state-of-the-art methods and therefore facilitates Bragg edge fitting at the voxel level. The proposed method requires significantly shorter exposure to retrieve features of interest. This in turn facilitates more efficient usage of expensive neutron beamline time and enables the full utilisation of state-of-the-art high resolution detectors. © 2021, CC BY.

关键词： Iterative methods

Spin-Energy Entanglement of a Time-Focused Neutron

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Leiner, Jonathan C. Kuhn, S.J. McKay, S. Jochum, J.K. Li, F. Irfan, A.A.M. Funama, F. Mettus, D. Beddrich, L. Franz, C. Shen, J. Parnell, S.R. Dalgliesh, R.M. Loyd, M. Geerits, N. Ortiz, G. Pfleiderer, C. Pynn, R. Neutron Technologies Division Oak Ridge National Laboratory Oak RidgeTN37830 United States Physik-Department Technische Universität München GarchingD-85748 Germany Technische Universität München GarchingD-85748 Germany Department of Physics Indiana University BloomingtonIN47405 United States Center for Exploration of Energy and Matter Indiana University BloomingtonIN47408 United States Institute for Quantum Computing University of Waterloo WaterlooONN2L 3G1 Canada Jülich Centre for Neutron Science JCNS Forschungszentrum Jülich GmbH Outstation at MLZ FRM-II GarchingD-85747 Germany Laboratory for Neutron Scattering and Imaging Paul Scherrer Institut Villigen5232 Switzerland Faculty of Applied Sciences Delft University of Technology Mekelweg 15 Delft2629 JB Netherlands ISIS Rutherford Appleton Laboratory Oxfordshire ChiltonOX11 0QX United Kingdom Atominstitut TU Wien Stadionallee 2 Vienna1020 Austria Quantum Science and Engineering Center Indiana University BloomingtonIN47408 United States Institute for Advanced Study PrincetonNJ08540 United States Technische Universität München GarchingD-85748 Germany Technische Universität München GarchingD-85748 Germany Neutron Sciences Directorate Oak Ridge National Laboratory Oak RidgeTN37830 United States

Intra-particle entanglement of individual particles such as neutrons could enable another class of scattering probes that are sensitive to entanglement in quantum systems and materials. In this work, we present experimental results demonstrating quantum contextuality as a result of entanglement between the spin and energy modes (i.e., degrees of freedom) of single neutrons in a beam using a pair of resonant radio-frequency neutron spin flippers in the MIEZE configuration (Modulated IntEnsity with Zero Effort). We verified the mode-entanglement by measuring a Clauser-Horne-Shimony-Holt (CHSH) contextuality witness S defined in the spin and energy subsystems, observing a clear breach of the classical bound of |S| ≤ 2, obtaining S = 2.40 ± 0.02. These entangled beams could enable alternative approaches for directly probing dynamics and entanglement in quantum materials whose low-energy excitation scales match those of the incident entangled neutron. Copyright © 2024, The Authors. All rights reserved.

关键词： Degrees of freedom (mechanics)

JARVIS-Leaderboard: A Large Scale Benchmark of Materials Design Methods

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Choudhary, Kamal Wines, Daniel Garrity, Kevin F. Williams, Maureen Tavazza, Francesca Li, Kangming Hattrick-Simpers, Jason Gupta, Vishu Romero, Aldo H. Krogel, Jaron T. Saritas, Kayahan Fuhr, Addis Ganesh, Panchapakesan Kent, Paul R.C. Yan, Keqiang Lin, Yuchao Ji, Shuiwang Blaiszik, Ben Reiser, Patrick Friederich, Pascal Agrawal, Ankit Tiwary, Pratyush Beyerle, Eric Minch, Peter Rhone, Trevor David Takeuchi, Ichiro Wexler, Robert B. Mannodi-Kanakkithodi, Arun Ertekin, Elif Mishra, Avanish Mathew, Nithin Wood, Mitchell Rohskopf, Andrew Dale Wang, Shih-Han Achenie, Luke E.K. Xin, Hongliang Biacchi, Adam J. Material Measurement Laboratory National Institute of Standards and Technology MD20899 United States Department of Materials Science and Engineering University of Toronto 27 King’s College Cir TorontoON Canada Department of Electrical and Computer Engineering Northwestern University EvanstonIL60208 United States Lewis-Sigler Institute for Integrative Genomics Princeton University PrincetonNJ08544 United States Ludwig Institute for Cancer Research Princeton University PrincetonNJ08544 United States Department of Physics and Astronomy West Virginia University MorgantownWV26506 United States Materials Science and Technology Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Center for Nanophase Materials Science Oak Ridge National Laboratory Oak RidgeTN37831 United States Computational Sciences and Engineering Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Computer Science and Engineering Texas A&M University College StationTX77843 United States Globus University of Chicago IL60637 United States Data Science Learning Division National Lab ArgonneIL60439 United States Institute of Nanotechnology Karlsruhe Institute of Technology Kaiserstraße 12 Karlsruhe76131 Germany Institute of Theoretical Informatics Karlsruhe Institute of Technology Kaiserstraße 12 Karlsruhe76131 Germany Department of Chemistry and Biochemistry Institute for Physical Science and Technology University of Maryland College ParkMD20742 United States Department of Physics Applied Physics and Astronomy Rensselaer Polytechnic Institute TroyNY12180 United States Department of Materials Science and Engineering University of Maryland College ParkMD20742 United States Department of Chemistry Institute of Materials Science and Engineering Washington University in St. Louis St. LouisMO63130 United States School of Materials Engineering Purdue University West LafayetteIN47907 United States Department of Mechan

Lack of rigorous reproducibility and validation are significant hurdles for scientific development across many fields. Materials science, in particular, encompasses a variety of experimental and theoretical approaches that require careful benchmarking. Leaderboard efforts have been developed previously to mitigate these issues. However, a comprehensive comparison and benchmarking on an integrated platform with multiple data modalities with perfect and defect materials data is still lacking. This work introduces JARVIS-Leaderboard, an open-source and community-driven platform that facilitates benchmarking and enhances reproducibility. The platform allows users to set up benchmarks with custom tasks and enables contributions in the form of dataset, code, and meta-data submissions. We cover the following materials design categories: Artificial Intelligence (AI), Electronic Structure (ES), Force-fields (FF), Quantum Computation (QC) and Experiments (EXP). For AI, we cover several types of input data, including atomic structures, atomistic images, spectra, and text. For ES, we consider multiple ES approaches, software packages, pseudopotentials, materials, and properties, comparing results to experiment. For FF, we compare multiple approaches for material property predictions. For QC, we benchmark Hamiltonian simulations using various quantum algorithms and circuits. Finally, for experiments, we use the inter-laboratory approach to establish benchmarks. There are 1281 contributions to 274 benchmarks using 152 methods with more than 8 million data-points, and the leaderboard is continuously expanding. The JARVIS-Leaderboard is available at the website: https://***/jarvis_leaderboard/ © 2023, CC BY.

关键词： Electronic structure

OBSERVABLE SETS, POTENTIALS AND SCHRÖDINGER EQUATIONS

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Huang, Shanlin Wang, Gengsheng Wang, Ming School of Mathematics and Statistics Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and Technology Wuhan430074 China Center for Applied Mathematics Tianjin University Tianjin300072 China School of Mathematics and Physics China University of Geosciences Wuhan430074 China

We characterize observable sets for 1-dim Schrödinger equations in R: i∂tu = (−∂2x + x2m)u (with m ∈ N:= {0, 1, . . . }). More precisely, we obtain what follows: First, when m = 0, E ⊂ R is an observable set at some time if and only if it is thick, namely, there is γ > 0 and L > 0 so that E \ [x, x + L] ≥ γL for each x ∈ R;Second, when m = 1 (m ≥ 2 resp.), E is an observable set at some time (at any time resp.) if and only if it is weakly thick, namely lim |E T[−x, x]| > 0. x x→+∞ From these, we see how potentials x2m affect the observability (including the geometric structures of observable sets and the minimal observable time). Besides, we obtain several supplemental theorems for the above results, in particular, we find that a half line is an observable set at time T > 0 for the above equation with m = 1 if and only if T > π2 .MSC Codes 93B07, 35J10 Copyright © 2020, The Authors. All rights reserved.

关键词：

The Importance of Bottom Friction on Thermal Structure During Freezing of Small Shallow Lakes in Qinghai-Tibet Plateau

学校读者我要写书评

暂无评论

Water Resources Research 2025年第6期61卷

作者： Mengxiao Wang Lijuan Wen Lauri Arvola Victor Stepanenko Dongsheng Su State Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou China Qinghai Lake Comprehensive Observation and Research Station Chinese Academy of Sciences Gangcha China Plateau Atmosphere and Environment Key Laboratory of Sichuan Province School of Atmospheric Sciences Chengdu University of Information Technology Chengdu China Lammi Biological Station University of Helsinki Lammi Finland Research Computing Center Lomonosov Moscow State University Moscow Russia Moscow Center for Fundamental and Applied Mathematics Moscow Russia

There are numerous seasonal ice-covered lakes on the Qinghai-Tibet Plateau (QTP), which significantly influence local climate and lake ecosystems through thermal processes. Two QTP lakes, Ngoring (NL) and BLH-A (BL), have similar latitudes, altitudes and climatic conditions. However, observed water temperature when freezing is lower in NL (about 0.5°C) and higher in BL (about 4°C). According to the novel lake thermal classification method proposed by Yang et al. (2021, https://***/10.1029/2020gl091374 ) (Yang's method), NL and BL should be classified as cryomictic and cryostratified, respectively. However, the results calculated using both the original and improved Yang's method classified both lakes as cryomictic. Clearly, Yang's method was applicable to NL but not suitable for BL. This was probably because the method only considered lake area, depth, and wind speed, but neglected energy dissipation caused by bottom friction. Additionally, the LAKE model was employed to investigate the bottom friction effect. Results indicated that the extent of bottom friction effect on the two lakes was different and jointly influenced by small surface area and shallow depth. When freezing, the water temperature of small BL is higher than that of the large Ngoring Lake, though they have similar altitudes, latitudes and climates The novel Yang's classification method cannot calculate the warm water temperature of BL when freezing for not considering bottom friction Bottom friction is important to water temperature of lakes when freezing, and it is jointly influenced by lake morphology, size and scope There are many seasonally ice-covered lakes on the QTP, which influence the local climate and lake ecosystems through thermal processes. Under similar geographic and climate conditions, NL (about 0.5°C) and BL (about 4°C) exhibit different water temperatures when freezing. Although the recently developed novel classification method for frozen lakes (Yang's method) correctly identi

关键词： Qinghai-Tibet Plateau bottom friction LAKE model warm water temperature ice formation

Quantum transduction of optical photons from a superconducting qubit

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Mirhosseini, Mohammad Sipahigil, Alp Kalaee, Mahmoud Painter, Oskar Kavli Nanoscience Institute and Thomas J. Watson Sr. Laboratory of Applied Physics California Institute of Technology PasadenaCA91125 United States Institute for Quantum Information and Matter California Institute of Technology PasadenaCA91125 United States AWS Center for Quantum Computing PasadenaCA91125 United States

Bidirectional conversion of electrical and optical signals lies at the foundation of the global internet. Such converters are employed at repeater stations to extend the reach of long-haul fiber optic communication systems and within data centers to exchange high-speed optical signals between computers. Likewise, coherent microwave-to-optical conversion of single photons would enable the exchange of quantum states between remotely connected superconducting quantum processors, a promising quantum computing hardware platform [1]. Despite the prospects of quantum networking [2], maintaining the fragile quantum state in such a conversion process with superconducting qubits has remained elusive. Here we demonstrate the conversion of a microwave-frequency excitation of a superconducting transmon qubit into an optical photon. We achieve this using an intermediary nanomechanical resonator which converts the electrical excitation of the qubit into a single phonon by means of a piezoelectric interaction [3], and subsequently converts the phonon to an optical photon via radiation pressure [4]. We demonstrate optical photon generation from the qubit with a signal-to-noise greater than unity by recording quantum Rabi oscillations of the qubit through single-photon detection of the emitted light over an optical fiber. With proposed improvements in the device and external measurement set-up, such quantum transducers may lead to practical devices capable of realizing new hybrid quantum networks [2, 5], and ultimately, distributed quantum computers [6, 7]. Copyright © 2020, The Authors. All rights reserved.

关键词： Qubits