检索结果-内蒙古大学图书馆

FIG-LP: Feature-Inverse-Graph based Link Prediction in Graph Stream

学校读者我要写书评

暂无评论

FIG-LP: Feature-Inverse-Graph based Link Prediction in Graph...

Symposia and Workshops on Ubiquitous, Autonomic and Trusted computing, UIC-ATC

作者： Xu Zhang XiaoQiang Xiao GuoWei Li WeiXun Ning JianTong Song School of Computer National University of Defense Technology ChangSha China State Key Laboratory of High Performance Computing ChangSha China

Link prediction is one of the essential issues in network science, which aims to find the unknown link or estimate the future link in networks. Existing methods are mainly based on the assumption that the network data is completely available and has stable distribution before analysis. In practice, however, complex networks evolve lifelong with massive data. The data in those networks is associated with previous ones, and the distribution will be non-stationary. Compared with conventional link prediction methods, online link prediction in the largescale dynamic network has three main challenges: i) How to analyze massive data with acceptable expenditure; ii) How to predict future links with less topological information; iii) How to make link prediction stably in a dynamic evolutionary network. In this paper, we propose a streaming link prediction model based on lifelong learning and graph neural networks (GNNs), which converts the link prediction problems to graph classification. Our main idea is to design a new topology, the Feature-Inverse-Graph, which turns node pairs into independent graphs and takes the features of the node pair as new vertices. Additionally, we apply a two-phase sampling sketch to deal with the massive data so that the complexity of the model within lifelong evolving networks could be acceptable. Then, the link prediction tasks in the regular graph is converted into a series of individually Feature-Inverse-Graph classifications. In this case, the computational cost of our model will not increase dramatically with the increase of network data, which is further verified by analyzing the computational complexity. The experimental results demonstrate the efficiency and effectiveness of our model by continuously predicting future links of classical datasets. In our experiments, several topological link prediction measures are chosen as features of node pair. For future work, the FIG-LP model can be used as the basic research of intelligent systems

关键词：

Benchmark modeling and 3D applications of solidification and macro-segregation based on an operator-splitting and fully decoupled scheme with term-wise matrix assembly

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Feng, Xiaoyu Chen, Huangxin Yu, Bo Sun, Shuyu Thuwal23955-6900 Saudi Arabia School of Mathematical Sciences Fujian Provincial Key Laboratory on Mathematical Modeling and High Performance Scientific Computing Xiamen University Xiamen361005 China School of Mechanical Engineering Beijing Institute of Petrochemical Technology Beijing102617 China

The solidification and macro-segregation problem involving unsteady multiphysics and multi-phase fields is typically a complex process with mass, momentum, heat, and species transfers among solid, mushy, and liquid phase regions. The quantitative prediction of phase change, chemical heterogeneities, and multi-phase and multi-component flows plays critical roles in many natural scenarios and industrial applications that involve many disciplines, like material, energy, and even planet science. In view of this, some scholars and research institutions have called for more contributors to join the benchmark analysis of solidification and segregation problems. Our work proposes an operator-splitting and matrix-based method to avoid non-linear systems. Also, the combination of vectorization and forward equation-based matrix assembly techniques enhances the implementability of extensions of 3D applications. Lastly, the novel scheme is well validated through a bunch of 2D and 3D benchmark cases. The numerical results also illustrate that this method can ensure accurate prediction and adequately capture the physical details of phenomena caused by the solutally and thermally driven flow, which include channel segregation, the formation of freckles, edge effect, aspect ratio effect, and 3D effect. Copyright © 2023, The Authors. All rights reserved.

关键词： Solidification

Physics-informed neural networks with residual/gradient-based adaptive sampling methods for solving PDEs with sharp solutions

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Mao, Zhiping Meng, Xuhui School of Mathematical Sciences Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific Computing Xiamen University Xiamen China Institute of Interdisciplinary Research for Mathematics and Applied Science School of Mathematics and Statistics Huazhong University of Science and Technology Wuhan430074 China

We consider solving the forward and inverse PDEs which have sharp solutions using physics-informed neural networks (PINNs) in this work. In particular, to better capture the sharpness of the solution, we propose adaptive sampling methods (ASMs) based on the residual and the gradient of the solution. We first present a residual only based ASM algorithm denoted by ASM I. In this approach, we first train the neural network by using a small number of residual points and divide the computational domain into a certain number of sub-domains, we then add new residual points in the sub-domain which has the largest mean absolute value of the residual, and those points which have largest absolute values of the residual in this sub-domain will be added as new residual points. We further develop a second type of ASM algorithm (denoted by ASM II) based on both the residual and the gradient of the solution due to the fact that only the residual may be not able to efficiently capture the sharpness of the solution. The procedure of ASM II is almost the same as that of ASM I except that in ASM II, we add new residual points which not only have large residual but also large gradient. To demonstrate the effectiveness of the present methods, we employ both ASM I and ASM II to solve a number of PDEs, including Burger equation, compressible Euler equation, Poisson equation over an L-shape domain as well as high-dimensional Poisson equation. It has been shown from the numerical results that the sharp solutions can be well approximated by using either ASM I or ASM II algorithm, and both methods deliver much more accurate solution than original PINNs with the same number of residual points. Moreover, the ASM II algorithm has better performance in terms of accuracy, efficiency and stability compared with the ASM I algorithm. This means that the gradient of the solution improves the stability and efficiency of the adaptive sampling procedure as well as the accuracy of the solution. Furthermore

关键词： Poisson equation

Benchmark Modeling and 3d Applications of Solidification and Macro-Segregation Based on an Operator-Splitting and Fully Decoupled Scheme with Term-Wise Matrix Assembly

学校读者我要写书评

暂无评论

SSRN

SSRN 2023年

The solidification and macro-segregation problem involving unsteady multi-physics and multi-phase fields is typically a complex process with mass, momentum, heat, and constituent transfers among solid, mushy, and liquid phase regions. The quantitative prediction of phase change, chemical heterogeneities, and multi-phase and multi-component flows plays critical roles in many natural scenarios and industrial applications that involve many disciplines, like material, energy, and even planet science. In view of this, some scholars and research institutions have called for more contributors to join the benchmark analysis of solidification and segregation problems. Our work proposes fully decoupled and iterative schemes based on operator-splitting and matrix-based ideas to avoid solving non-linear systems directly. Also, the combination of direct vectorization and equation-based forward matrix assembly techniques enhances the implementability and efficiency of extensions to 3D applications. Lastly, the novel scheme is well validated through a bunch of 2D and 3D benchmark cases. The numerical results also illustrate that this method can ensure accurate prediction and efficient computation. It adequately captures the physical details of phenomena caused by the solutally and thermally driven flow, which include channel segregation, the formation of freckles, edge effect, aspect ratio effect, and 3D effect. © 2023, The Authors. All rights reserved.

关键词： Solidification

FRCNet: Frequency and Region Consistency for Semi-supervised Medical Image Segmentation

学校读者我要写书评

暂无评论

arXiv 2024年

作者： He, Along Li, Tao Wu, Yanlin Zou, Ke Fu, Huazhu Tianjin Key Laboratory of Network and Data Security Technology College of Computer Science Nankai University Tianjin China Haihe Lab of ITAI China National Key Laboratory of Fundamental Science on Synthetic Vision Sichuan University Sichuan Chengdu China Institute of High Performance Computing Agency for Science Technology and Research Singapore

Limited labeled data hinder the application of deep learning in medical domain. In clinical practice, there are sufficient unlabeled data that are not effectively used, and semi-supervised learning (SSL) is a promising way for leveraging these unlabeled data. However, existing SSL methods ignore frequency domain and region-level information and it is important for lesion regions located at low frequencies and with significant scale changes. In this paper, we introduce two consistency regularization strategies for semi-supervised medical image segmentation, including frequency domain consistency (FDC) to assist the feature learning in frequency domain and multi-granularity region similarity consistency (MRSC) to perform multi-scale region-level local context information feature learning. With the help of the proposed FDC and MRSC, we can leverage the powerful feature representation capability of them in an effective and efficient way. We perform comprehensive experiments on two datasets, and the results show that our method achieves large performance gains and exceeds other state-of-the-art methods. © 2024, CC BY.

关键词： Deep learning

The analytic smoothing effect of solutions for the nonlinear spatially homogeneous Landau equation with hard potentials

学校读者我要写书评

暂无评论

Science China Mathematics 2022年第10期65卷 2079-2098页

作者： Hao-Guang Li Chao-Jiang Xu School of Mathematics and Statistics South-Central Minzu UniversityWuhan 430074China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) Ministry of Industry and Information TechnologyNanjing 211106China Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Laboratoire de Mathematiques Universite de Rouen NormandieCNRS UMR 6085Saint-Etienne-du-Rouvray 76801France

In this work,we study the Cauchy problem of the nonlinear spatially homogeneous Landau equation with hard potentials in a close-to-equilibrium *** prove that the solution to the Cauchy problem with the initial datum in L^(2)enjoys an analytic regularizing effect,and the evolution of the analytic radius is the same as that of heat equations.

关键词： spatially homogeneous Landau equation analytic smoothing effect hard potentials

FPGA-Based Multi-precision Architecture for Accelerating Large-Scale Floating-Point Matrix computing 17th

学校读者我要写书评

暂无评论

FPGA-Based Multi-precision Architecture for Accelerating Lar...

17th IFIP WG 10.3 International Conference on Network and Parallel computing, NPC 2020

作者： Zhang, Longlong Peng, Yuanxi Hu, Xiao Huang, Ahui Tian, Tian State Key Laboratory of High Performance Computing School of Computer National University of Defense Technology Changsha China Institute of Microelectronics School of Computer National University of Defense Technology Changsha China

ISBN: (纸本)9783030794774

Matrix computing plays a vital role in many scientific and engineering applications, but previous work can only handle the data with specified precision based on FPGA. This study first presents algorithms, data flows, and mapping strategies to match the hardware structure for matrix computing of different precisions. Then, we propose a unified multi-precision matrix computing unit core that can handle three precisions and three matrix operation modes and can be used as a coprocessor for large-scale matrix computing which has advantages of low storage and high efficiency. Finally, we build a complete matrix computing acceleration system and deploy it on FPGA using 128 processing elements (PEs). The experimental results show that the accelerator achieves a maximum frequency of 180 MHz, and matrix computing of double-precision, single-precision, and half-precision floating-point data performs 46.1 GFLOPS, 92.1 GFLOPS, and 184.3 GFLOPS respectively, which is superior to other current designs in terms of application range and performance. © 2021, IFIP International Federation for Information Processing.

关键词： Field programmable gate arrays (FPGA)

high-throughput development and applications of the compositional mechanical property map of the β titanium alloys

学校读者我要写书评

暂无评论

Journal of Materials Science & technology 2021年第12期71卷 201-210页

作者： Jinfeng Ling Dandan Huang Kewu Bai Wei Li Zhentao Yu Weimin Chen Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhouGuangdong510632China Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials Guangxi UniversityNanningGuangxi530004China Institute of High Performance Computing Agency for ScienceTechnology and ResearchSingapore138632Singapore

By a combination of the nanoindentation and electron probe microanalysis(EPMA)techniques,the traditional diffusion couple technique is extended to map the mechanical property of β-type Ti alloys over a wide composition range,which can be utilized to develop very versatile novel bio-Ti alloys for hard tissue re placements in arti ficial bones,joints,and dental *** create complete single-phase composition ranges of Ti-based bcc solid solution,12 types of bcc Ti-Nb-Zr-Mo/Ti-Nb-Zr-Ta quaternary diffusion couples were fabricated and annealed at 1273 K for 25 *** this way,the composition-mechanical property relationships in the vast composition space of Ti-based alloys were established using EPMA and nanoindentation ***,the measured composition-dependent Young’s moduli,hardness,and elastic recovery as well as the derived ratio of hardness to Young’s modulus,and the ratio of the cube of hardness to the square of Young’s modulus,in the developed compositional mechanical property database,were visualized in a five-dimensional scatter *** enables an effective tool to screen the Ti-Nb-Zr-based alloys fororthopedic and dental applications according to different clinical requirements,and to rationalize the fundamental mechanical relationships in the rapid development of β-Ti alloys.

关键词： Mechanical properties Ti–Nb–Zr–Mo and Ti–Nb–Zr–Ta alloys Diffusion couple Nanoindentation

DUNE: Improving Accuracy for Sketch-INT Network Measurement Systems

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Wei, Zhongxiang Tian, Ye Chen, Wei Gu, Liyuan Zhang, Xinming The Anhui Key Laboratory of High Performance Computing School of Computer Science and Technology University of Science and Technology of China Anui Hefei230026 China

In-Band Network Telemetry (INT) and sketch algorithms are two representative methodologies for measuring network traffics in real time. To combine sketch with INT and to keep their advantages, the "reconstructing sketch at end-host" approach, which uses INT to send small pieces of switch sketch (i.e., sketchlet) to end-host for reconstructing an identical sketch, is a promising direction. However, we reveal that the naive column sketchlet is not efficient, and inaccuracies arise because of the invalid and stale measurement data in the end-host reconstructed sketch. In this paper, we present an innovative sketch-INT measurement system named DUNE. DUNE is lightweight by following the "reconstructing the sketch at end-host" approach, and to improve the measurement accuracy, we make two innovations: First, we design a novel sketchlet named scatter sketchlet that is more efficient in transferring measurement data by allowing a switch to select individual sketch buckets to add to sketchlet;Second, we develop data structures for tracing "freshness" of the sketch buckets, and present algorithms for smartly selecting buckets that contain valuable measurement data to send to end-host. We theoretically prove that our proposed methods are superior comparing with the existing solution, and implement a prototype on the commodity Barefoot Tofino switches. We conduct extensive experiments on DUNE, and the evaluation results show that the system considerably improves measurement accuracies at negligible costs. In particular, with less than 0.36% loss of the packet forwarding rate, DUNE avoids up to 60% errors in the end-host reconstructed sketch. Copyright © 2022, The Authors. All rights reserved.

关键词：