检索结果-内蒙古大学图书馆

Put Three and Three Together: Triangle-Driven Community Detection

ACM TRANSACTIONS ON KNOWLEDGE DISCOVERY FROM DATA 2016年第3期10卷 22-22页

作者： Prat-Perez, Arnau Dominguez-Sal, David Brunat, Josep-M. Larriba-Pey, Josep-Lluis Univ Politecn Cataluna DAMA UPC ES-08034 Barcelona Spain Spars Technol Lucknow Uttar Pradesh India Univ Politecn Cataluna Dept Matemat Aplicada 2 ES-08034 Barcelona Spain

Community detection has arisen as one of the most relevant topics in the field of graph data mining due to its applications in many fields such as biology, social networks, or network traffic analysis. Although the existing metrics used to quantify the quality of a community work well in general, under some circumstances, they fail at correctly capturing such notion. The main reason is that these metrics consider the internal community edges as a set, but ignore how these actually connect the vertices of the community. We propose the Weighted Community Clustering (WCC), which is a new community metric that takes the triangle instead of the edge as the minimal structural motif indicating the presence of a strong relation in a graph. We theoretically analyse WCC in depth and formally prove, by means of a set of properties, that the maximization of WCC guarantees communities with cohesion and structure. In addition, we propose Scalable Community Detection (SCD), a community detection algorithm based on WCC, which is designed to be fast and scalable on SMP machines, showing experimentally that WCC correctly captures the concept of community in social networks using real datasets. Finally, using ground-truth data, we show that SCD provides better quality than the best disjoint community detection algorithms of the state of the art while performing faster.

关键词： Community detection social networks parallel algorithm scalable algorithm triangles

来源：评论

学校读者我要写书评

暂无评论

An investigation of hybrid CPU-GPU solvers for supersonic reacting flow simulation with detailed chemical kinetics

引用

AEROSPACE SCIENCE AND TECHNOLOGY 2022年 126卷

作者： Rao, Sihang Xu, Xu Chen, Bing Yang, Qingchun Beihang Univ Sch Astronaut Beijing 100191 Peoples R China

Accurate simulations of supersonic reacting flow require the use of detailed chemical kinetics to capture the complex phenomena such as auto-ignition and broken, thickened flamelets. However, the detailed chemical mechanisms for hydrocarbon fuels used in supersonic combustion typically have a great number of species and reactions. This paper reports on the implementation of a hybrid CPU-GPU solver by using the graphics processing unit (GPU) as a coprocessor to accelerate the computation of chemical source terms in modeling supersonic reacting flows with detailed chemical kinetics. The chemical kinetics are solved explicitly via a fully-coupled method with an implicit scheme. Three parallel strategies with different storage schemes were explored in implementing the highly parallel GPU algorithms for accelerating combustion modeling. Significant acceleration was obtained by using these parallel algorithms for chemical source terms evaluation. In order to verify the viability of the solver, two supersonic combustion flow test cases were conducted. The performance of these algorithms is evaluated by modeling four chemical reaction mechanisms on different grids compared with the CPU-only solver. The computation cost of these algorithms is basically proportional to the size of the grids. The performance gain of these parallel algorithms depends on the size of the reaction mechanism. A maximum speedup factor of over 80 was obtained by modeling the mechanism consisting of 348 species and 2163 reactions. The significant performance improvement provided by these parallel algorithms can provide a significant perspective for designing GPU-accelerated algorithms for applications in simulating supersonic reacting flows. (C) 2022 Elsevier Masson SAS. All rights reserved.

关键词： Supersonic reacting flow Computational fluid dynamics GPU Detailed chemical kinetics parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Simulation of Seismic Wave Propagation in a Multicomponent Oil Deposit Model

引用

INTERNATIONAL JOURNAL OF APPLIED MECHANICS 2020年第8期12卷

作者： Golubev, Vasily Shevchenko, Alexey Petrov, Igor Moscow Inst Phys & Technol Lab Appl Numer Geophys Inst Sky Lane 9 Dolgoprudnyi 141700 Moscow Region Russia

A seismic survey is perhaps the most common geophysical technique used to locate potential oil and natural gas deposits in the geologic structures. Thanks to the rapid development of modern high-performance computing systems, the computer simulation technology plays a crucial role in processing the field data. The precision of the full-waveform inversion (FWI) essentially depends on the quality of the direct problem solver. This paper introduces a new approach to the numerical simulation of wave processes in complex heterogeneous media. The linear elasticity theory is applied to simulate the dynamic behavior of curvilinear geological layers. In contrast to the conventional approach, the producing oil formation is described in the frame of a porous fluid-filled model. It allows us to explicitly take into account the porosity, oil density, and other physical parameters. The method of setting the physically correct contact conditions between the reservoir and the geological massif based on the transport equation solution for Riemann invariants was successfully implemented. The grid-characteristic method, previously thoroughly verified on acoustic and elastic problems, was adopted. The explicit time-stepping procedure was derived for a two-dimensional case with a method of splitting along coordinate axes. This method guarantees the preservation of the scheme approximation order. The potential application of the new method to a complex model based on the data from the famous Russian oil deposit - the Bazhen Formation - is demonstrated. The seismic responses were registered on the wave fields and synthetic seismograms. The novelty of this paper relates to a uniform approach to the wave propagation simulation in the heterogeneous medium containing contacting subdomains with different rheology types.

关键词： Mathematical modeling numerical method parallel algorithm seismic wave seismic survey process porous medium Biot model

来源：评论

学校读者我要写书评

暂无评论

PMFFRC: a large-scale genomic short reads compression optimizer via memory modeling and redundant clustering

引用

BMC BIOINFORMATICS 2023年第1期24卷 454-454页

作者： Sun, Hui Zheng, Yingfeng Xie, Haonan Ma, Huidong Liu, Xiaoguang Wang, Gang Nankai Univ Coll Comp Sci Nankai Baidu Joint Lab Tianjin Peoples R China Guangxi Univ Sch Elect Engn Inst Artificial Intelligence Nanning Peoples R China

BackgroundGenomic sequencing reads compressors are essential for balancing high-throughput sequencing short reads generation speed, large-scale genomic data sharing, and infrastructure storage expenditure. However, most existing short reads compressors rarely utilize big-memory systems and duplicative information between diverse sequencing files to achieve a higher compression ratio for conserving reads data storage *** employ compression ratio as the optimization objective and propose a large-scale genomic sequencing short reads data compression optimizer, named PMFFRC, through novelty memory modeling and redundant reads clustering technologies. By cascading PMFFRC, in 982 GB fastq format sequencing data, with 274 GB and 3.3 billion short reads, the state-of-the-art and reference-free compressors HARC, SPRING, Mstcom, and FastqCLS achieve 77.89%, 77.56%, 73.51%, and 29.36% average maximum compression ratio gains, respectively. PMFFRC saves 39.41%, 41.62%, 40.99%, and 20.19% of storage space sizes compared with the four unoptimized *** rational usage big-memory of compression server, effectively saving the sequencing reads data storage space sizes, which relieves the basic storage facilities costs and community sharing transmitting overhead. Our work furnishes a novel solution for improving sequencing reads compression and saving storage space. The proposed PMFFRC algorithm is packaged in a same-name Linux toolkit, available un-limited at https://***/fahaihi/PMFFRC.

关键词： Short reads data Data compression Fastq parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

Multiswarm Artificial Bee Colony algorithm based on spark cloud computing platform for medical image registration

引用

COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020年 192卷 105432-105432页

作者： Wen, Tingxi Liu, Haotian Lin, Luxin Wang, Bin Hou, Jigong Huang, Chuanbo Pan, Ting Du, Yu Huaqiao Univ Coll Engn Quanzhou 362021 Peoples R China Fujian Prov Key Lab Data Intens Comp Quanzhou 362021 Peoples R China Fujian Key Lab Autonomous Controllable Software Quanzhou 362000 Peoples R China Postdoctoral Workstn Linewell Software Co Ltd Quanzhou 362000 Peoples R China

Background Over the years, medical image registration has been widely used in various fields. However, different application characteristics, such as scale, computational complexity, and optimization goals, can cause problems. Therefore, developing an optimization algorithm based on clustering calculation is *** To solve the aforementioned problem, a multiswarm artificial bee colony (MS-ABC) multi-objective optimization algorithm based on clustering calculation is proposed. This algorithm can accelerate the resolution of complex problems on the Spark platform. Experiments show that the algorithm can optimize certain conventional complex problems and perform medical image registration *** Results show that the MS-ABC algorithm demonstrates excellent performance in medical image registration tests. The optimization results of the MS-ABC algorithm for conventional problems are similar to those of existing algorithms; however, its performance is more time efficient for complex problems, especially when additional goals are *** The MS-ABC algorithm is applied to the Spark platform to accelerate the resolution of complex application problems. It can solve the problem of traditional algorithms regarding long calculation time, especially in the case of highly complex and large amounts of data, which can substantially improve data-processing efficiency.

关键词： parallel algorithm Mapreduce Spark platform Medical image registration Multiswarm artificial bee colony

来源：评论

学校读者我要写书评

暂无评论

Planar Graph Perfect Matching Is in NC

引用

JOURNAL OF THE ACM 2020年第4期67卷 21-21页

作者： Anari, Nima Vazirani, Vijay V. Stanford Univ Comp Sci Dept 353 Serra Mall Stanford CA 94305 USA Univ Calif Irvine Donald Bren Sch Informat & Comp Sci 6210 Donald Bren Hall Irvine CA 92697 USA

Is perfect matching in NC? That is, is there a deterministic fast parallel algorithm for it? This has been an outstanding open question in theoretical computer science for over three decades, ever since the discovery of RNC perfect matching algorithms. Within this question, the case of planar graphs has remained an enigma: On the one hand, counting the number of perfect matchings is far harder than finding one (the former is #P-complete and the latter is in P), and on the other, for planar graphs, counting has long been known to be in NC whereas finding one has resisted a solution. In this article, we give an NC algorithm for finding a perfect matching in a planar graph. Our algorithm uses the above-stated fact about counting perfect matchings in a crucial way. Our main new idea is an NC algorithm for finding a face of the perfect matching polytope at which a set (which could be polynomially large) of conditions, involving constraints of the polytope, are simultaneously satisfied. Several other ideas are also needed, such as finding, in NC, a point in the interior of the minimum-weight face of this polytope and finding a balanced tight odd set.

关键词： parallel algorithm planar graph perfect matching Tutte matrix Pfaffian

来源：评论

学校读者我要写书评

暂无评论

parallelized maximization of nonmonotone one-sided σ-smooth function

引用

COMPUTERS & ELECTRICAL ENGINEERING 2023年 105卷

作者： Zhang, Hongxiang Xu, Dachuan Zhang, Yapu Zhang, Zhenning Beijing Univ Technol Inst Operat Res & Informat Engn Beijing 100124 Peoples R China

In this paper, we study the problem of maximizing a nonmonotone nonnegative one-sided sigma-smooth (OSS) function G(x). For a downwards-closed basis polyhedron constraint, we propose two classes of parallel algorithms under deterministic and random settings. For the deterministic nonmonotone OSS problem, we design the Jump-Start parallel Frank Wolfe (JSPFW) algorithm and obtain an approximation solution of (e(-1) - e(-2) - O(epsilon)). The JSPFW algorithm has (O(log n/epsilon(2))) adaptive rounds and O(n log n/epsilon(2)) queries about function and its gradient value. For the stochastic OSS problem, we design the Stochastic parallel Frank Wolfe (SPFW) algorithm and get the (e(-1) - e(-2))(1 - O(epsilon))(1 - o(1)) approximation solution. The SPFW algorithm needs O(n(2)) adaptive rounds and consumes O(n(2)) queries about gradient function value.

关键词： OSS function parallel algorithm Down-closed Frank Wolfe

来源：评论

学校读者我要写书评

暂无评论

Scalable implementation of polynomial filtering for density functional theory calculation in PARSEC

引用

COMPUTER PHYSICS COMMUNICATIONS 2020年 254卷 107330-107330页

作者： Liou, Kai-Hsin Yang, Chao Chelikowsky, James R. Univ Texas Austin McKetta Dept Chem Engn Austin TX 78712 USA Lawrence Berkeley Natl Lab Computat Res Div Berkeley CA 94720 USA Univ Texas Austin Dept Phys Austin TX 78712 USA Univ Texas Austin Ctr Computat Mat Oden Inst Computat Engn & Sci Austin TX 78712 USA

We present an efficient implementation of polynomial filtering methods in PARSEC, a real-space pseudopotential based Kohn-Sham density functional theory solver. The implementation described here improves upon a Chebyshev-filtered subspace iteration algorithm used in the previous version of PARSEC. We present a hybrid polynomial filtering scheme that combines Chebyshev-filtered subspace iteration and a spectrum slicing method that partitions the spectrum into several spectral slices and uses bandpass-filtered subspace iteration to compute approximate eigenpairs within each interior slice simultaneously. We describe a procedure to partition a spectrum and construct polynomial filters. We also discuss a number of practical issues such as the use of appropriate data layouts for carrying out the computation on a two-dimensional process grid and how to achieve good load balance by allocating an appropriate number of process groups to each spectral slice. Numerical examples are presented to demonstrate the effectiveness of the hybrid polynomial filtering method as well as the superior parallel scalability of spectrum slicing in comparison to that of Chebyshev-filtered subspace iteration. (C) 2020 Elsevier B.V. All rights reserved.

关键词： parallel algorithm Electronic structure Density functional theory Eigenvalue problem Polynomial filtering Spectrum slicing

来源：评论

学校读者我要写书评

暂无评论

A Complementary Topographic Feature Detection algorithm Based on Surface Curvature for Three-Dimensional Level-Set Functions

引用

JOURNAL OF SCIENTIFIC COMPUTING 2023年第3期94卷 71-71页

作者： Lenz, Christoph Aguinsky, Luiz Felipe Hossinger, Andreas Weinbub, Josef TU Wien Inst Microelect Christian Doppler Lab High Performance TCAD Gusshausstr 27-29 A-1040 Vienna Austria Silvaco Europe Ltd Compass Point St Ives Cambridge PE27 5JL England

The level-set method is widely used in expanding front simulations in numerous fields of computational research, such as computer graphics, physics, or microelectronics. In the latter, the level-set method is employed for topography simulations of semiconductor device fabrication processes, being driven by complicated physical and chemical models. These models tend to produce surfaces with critical points where accuracy is paramount. To efficiently increase the accuracy in regions neighboring these critical points, automatic hierarchical domain refinement is required, guided by robust feature detection. Feature detection has to be computationally efficient and sufficiently accurate to reliably detect the critical points. To that end, we present a fast parallel geometric feature detection algorithm for three-dimensional level-set functions. Our approach is based on two different, complementary curvature calculation methods of the zero level-set and an optimized feature detection parameter to detect features. For performance reasons, our algorithm can be in principal linked to different curvature calculation methods, however, as will be discussed, two particularly attractive options are available: (i) A novel extension of the standard curvature calculation method for level-set functions, and (ii) an often disregarded method for calculating the curvature due to its purported low numerical accuracy. We show, however, that the latter is still a viable option, and that our algorithm is able to reliably detect features on geometries stemming from complicated, practically relevant geometries. Our algorithm and findings are applicable to other fields of applications such as surface simplification.

关键词： Level-set method Curvature Feature detection parallel algorithm

来源：评论

学校读者我要写书评

暂无评论

SHAPE-RECOGNITION USING A FIXED-SIZE VLSI ARCHITECTURE

引用

INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE 1995年第1期9卷 1-21页

作者： CHENG, HD CHENG, X CONCORDIA UNIV DEPT COMP SCIMONTREALPQ H3G 1M8CANADA UTAH STATE UNIV DEPT COMP SCILOGANUT 84322

Shape recognition is an important research area in pattern recognition. It also has wide practical applications in many fields. An attribute grammar approach to shape recognition combines both the advantages of syntactic and statistical methods and makes shape recognition more accurate and efficient. However, the time complexity of a sequential shape recognition algorithm using attribute grammar is O(n(3)) where n is the length of an input string. When the problem size is very large it needs much more computing time, therefore a high speed parallel shape recognition is necessary to meet the demands of some real-time applications. This paper presents a parallel shape recognition algorithm and also discusses the algorithm partition problem as well as its implementation on a fixed-size VLSI architecture. The proposed algorithm has time complexity O(n(3)/k(2)) if using k x k processing elements. When k = n, its time complexity is O(n). The experiment has been conducted to verify the performance of the proposed algorithm. The correctness of the algorithm partition and the behavior of the proposed VLSI architecture have also been proved through the experiment. The results indicate that the proposed algorithm and the VLSI architecture could be very useful to imaging processing, pattern recognition and related areas, especially for real-time applications.

关键词： SHAPE RECOGNITION ATTRIBUTE GRAMMAR parallel algorithm VLSI ARCHITECTURE REAL-TIME PROCESSING

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：