检索结果-内蒙古大学图书馆

Parallel Jacobian-free Newton Krylov discrete ordinates method for pin-by-pin neutron transport models

FRONTIERS IN ENERGY RESEARCH 2023年 10卷

作者： Zhang, Yangyi Zhou, Xiafeng Huazhong Univ Sci & Technol Sch Energy & Power Engn Dept Nucl Engn & Technol Wuhan Peoples R China Huazhong Univ Sci & Technol Inst Interdisciplinary Res Math & Appl Sci Wuhan Peoples R China

A parallel Jacobian-Free Newton Krylov discrete ordinates method (comePSn_JFNK) is proposed to solve the multi-dimensional multi-group pin-by-pin neutron transport models, which makes full use of the good efficiency and parallel performance of the JFNK framework and the high accuracy of the Sn method for the large-scale models. In this paper, the k-eigenvalue and the scalar fluxes (rather than the angular fluxes) are chosen as the global solution variables of the parallel JFNK method, and the corresponding residual functions are evaluated by the Koch-Baker-Alcouffe (KBA) algorithm with the spatial domain decomposition in the parallel Sn framework. Unlike the original Sn iterative strategy, only a "flattened " power iterative process which includes a single outer iteration without nested inner iterations is required for the JFNK strategy. Finally, the comePSn_JFNK code is developed in C++ language and, the numerical solutions of the 2-D/3-D KAIST-3A benchmark problems and the 2-D/3-D full-core MOX/UOX pin-by-pin models with different control rod distribution show that comePSn_JFNK method can obtain significant efficiency advantage compared with the original power iteration method (comePSn) for the parallel simulation of the large-scale complicated pin-by-pin models.

关键词： parallel Jacobian-free Newton-Krylov method parallel discrete ordinates method pin-by-pin neutron transport model three-dimensional multi-group k-eigenvalue problem acceleration algorithm

来源：评论

学校读者我要写书评

暂无评论

A Stride-Based Convolution Decomposition Method to Stretch CNN acceleration algorithms for Efficient and Flexible Hardware Implementation

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2020年第9期67卷 3007-3020页

作者： Yang, Chen Wang, Yizhou Wang, Xiaoli Geng, Li Xi An Jiao Tong Univ Sch Microelect Xian 710049 Peoples R China

To reduce multiplication operations in convolution of convolutional neural networks (CNNs), there are three widely used convolutional acceleration algorithms, i.e., Winograd, FFT and FFA. However, current accelerators based on these convolutional acceleration algorithms have issues on flexibility and efficiency. Firstly, some accelerators utilized a combination of these acceleration algorithms and employed multiple types of computational units to achieve their respective advantages. As a result, some computational units are left unused when the best-performing unit is working, which causes much area inefficiency. Secondly, current accelerators tend to choose small parameters of these convolutional acceleration algorithms to avoid unacceptable precision loss, as a result, they are hardly to support large kernel sizes and lack of flexibility. Thirdly, these acceleration algorithms are typically presented for 1-stride convolutions, consequently, few implementation considers the acceleration of large-stride convolutions, which is a major restriction to hardware flexibility. This paper proposed a stride-based convolution decomposition method (SCDM) to reform different convolution shapes (i.e., kernel sizes & strides) to an identical pattern. With the aid of SCDM, a Winograd-stretched and hardware-efficient design (WHD) is presented to utilize one uniform computational unit for the acceleration of different convolution shapes, which combines complementary performance advantages on both Winograd F(4,3)andF(4,2) units. Compared to current FFT-based or FFA-based works, WHD can stretch the use range of Winograd and simplify implementation, thereby achieving hardware flexibility and efficiency. Evaluation results show that 34.08%similar to 55.41% operation reduction were achieved on six CNN models, while incurring a slight hardware overhead.

关键词： Convolutional neural networks acceleration algorithm convolution decomposition flexibility hardware-efficient

来源：评论

学校读者我要写书评

暂无评论

ABET: an affective emotion-topic method of biterms for emotion recognition from the short texts

引用

JOURNAL OF AMBIENT INTELLIGENCE AND HUMANIZED COMPUTING 2022年第10期14卷 13451-13463页

作者： Pradhan, Anima Senapati, Manas Ranjan Sahu, Pradip Kumar Veer Surendra Sai Univ Technol Dept Informat Technol Burla India

Nowadays, online users write short messages to share their feelings on social networking sites, such as discussion forums, question answering websites, etc., making these sites very popular. The increase in these short-term messages causes a huge data sparsity, making emotion recognition a challenging task. Therefore, a word co-occurrence pattern called biterms is generated from a large-scale dataset to prevent severe data sparsity issues. The topic modeling algorithms and acceleration algorithms are implemented to extract more reliable topics from the group of terms. Based on biterm technique, in this paper, a new algorithm called "Affected biterm emotion topic" is proposed for emotion recognition from a short text. For the experimental purpose, two popular short text datasets, SemEval and International Survey on Emotion Antecedents and Reactions (ISEAR), are used to investigate the performance of the proposed algorithm with the benchmark methods light latent dirichlet allocation (LLDA), biterm topic model (BTM), emotion-topic model (ETM), contextual sentiment topic model (CSTM), Sentiment latent topic model (SLTM) and siasme network based supervised topic model (SNSTM). The proposed algorithm is evaluated using the benchmark methods for mean, variance, and accuracy. The experimental result shows that the proposed algorithm is effective in analyzing emotions.

关键词： BTM Topic model Alias method Metropolis-Hastings acceleration algorithm Emotion classification Short text analysis

来源：评论

学校读者我要写书评

暂无评论

A new computationally efficient algorithm to generate global fractional vegetation cover from Sentinel-2 imagery at 10 m resolution

引用

INTERNATIONAL JOURNAL OF DIGITAL EARTH 2024年第1期17卷

作者： Ma, Xu Ding, Jianli Sun, Hui Lu, Lei Cheng, Xiao Zhang, Fei Xu, Zhonglin Xingjiang Univ Coll Geog & Remote sensing Sci Xinjiang key Lab Oasis Ecol Postdoctoral Mobile Stn Urumqi Peoples R China Xingjiang Univ Coll Geog & Remote sensing Sci Xinjiang key Lab Oasis Ecol Urumqi Peoples R China Lanzhou Univ Coll Earth & Environm Sci Lanzhou Peoples R China Sun Yat sen Univ Polar Sci Ctr Sch Geospatial Engn & Sci Off Sci Res & Dev Zhuhai Peoples R China Zhejiang Normal Univ Coll Geog & Environm Sci Jinhua 321000 Peoples R China Xingjiang Univ Coll Ecol & Environm Sci Urumqi Peoples R China

The multi-angle method in the pixel dichotomy model (PDM) is used to produce fine spatial resolution (FSR) products of fractional vegetation cover (FVC), which involves numerous iterative computations. This phenomenon causes a low computational efficiency for global FVC. Here, we established the multi-angle equations, and simplified the two-stream approximation method to obtain multi-angle reflectance, which calculated the KDM parameters possible. Moreover, to accelerate the calculation of parameters in the multi-angle equations, land cover data were utilized as priority knowledge, which aims to decrease iterative computations to speed up the computational speed. Finally, we proposed an accelerated pixel dichotomy coupled linear kernel-driven model (PDKDM-A). By validating PDKDM-A using field measurements and FVC products, we found that the global FVC computed for various land covers exhibited strong agreement with the field measurements. The root mean square errors (RMSEs) were consistently below 0.150, except for grasslands, croplands, and cropland/natural vegetation mosaics. When comparing FVC products on the same scale, we discovered that the RMSE was less than 0.103, except for deciduous broadleaf forests. Our study demonstrates that PDKDM-A is an efficient algorithm, with the potential to quickly generate accurate global FVC products with fine spatial resolution.

关键词： Multi-angle method global FVC modified PDM high spatial resolution image acceleration algorithm

来源：评论

学校读者我要写书评

暂无评论

Design of electromagnetic situation visualization system 2

Design of electromagnetic situation visualization system

引用

2nd International Conference for Information Systems and Design (ICID)

作者： Hu, Haojie Fang, Shengliang Space Engn Univ Beijing Peoples R China

ISBN: (纸本)9781665420655

The accurate description and clear visualization of electromagnetic situation is the basis and key for people to recognize the electromagnetic environment, grasp the battlefield situation and win the future war. This paper discusses the basic methods of electromagnetic situation visualization from time domain, frequency domain, airspace and energy domain, and summarizes the specific content of electromagnetic situation display and the key issues of current research. This paper analyzes the basic problems, principles and methods of electromagnetic situation visualization system design, gives the architecture design of electromagnetic situation visualization system, and looks forward to the research methods of electromagnetic situation.

关键词： electromagnetic situation Lectromagnetic environment modeling Visualization acceleration algorithm System design

来源：评论

学校读者我要写书评

暂无评论

acceleration of adjoint-based adaptation through sub-iterations

引用

COMPUTERS & FLUIDS 2020年 202卷 104491-104491页

作者： Ding, Kaihua Fidkowski, Krzysztof J. Univ Michigan Dept Aerosp Engn Ann Arbor MI 48109 USA

In this paper, we introduce an algorithm for reducing the cost of output-based error estimation and mesh adaptation through the use of a sub-iteration algorithm. A single sub-iteration is an adaptation iteration in which the most expensive solves-the primal and fine-space adjoint-are calculated only approximately. We intersperse sub-iterations with standard full-solve iterations to obtain accurate error estimates. The use of sub-iterations in between full-solves reduces the computational cost while improving solution accuracy per full-solve iteration. We demonstrate this method for steady, compressible Euler and Navier-Stokes simulations, discretized with the discontinuous Galerkin (DG) finite-element method. Because the acceleration in the output-based method is based on sub-iterations of the adaptation cycle, regardless of the discretization, the idea is not specific to DG and can be applied to general discretizations. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： acceleration algorithm Adjoint-based methods Error estimation Discontinuous Galerkin Mesh adaptation

来源：评论

学校读者我要写书评

暂无评论

An accelerated conservative sharp-interface method for multiphase flows simulations

引用

JOURNAL OF COMPUTATIONAL PHYSICS 2021年 429卷 110021-110021页

作者： Long, Tian Cai, Jinsheng Pan, Shucheng Northwestern Polytech Univ Sch Aeronaut Xian 710072 Peoples R China

In this paper, we develop an accelerated conservative sharp-interface method for multiphase flows simulations. Traditional multiphase simulation methods use the minimum time step of all fluids obtained according to the CFL conditions to evolve the fluid states, which limits the computational efficiency, as the sound speed of one fluid may be much larger than of others. To address this issue, based on the original conservative sharpinterface methods, the present method is proposed by solving the governing equations of each individual fluid with the corresponding time step. Without violating the numerical stability requirement, the states of one fluid containing larger time-scale features will be evolved with a larger time step. The interaction step between two fluids is solved for synchronization, which is handled by interpolating the intermediate states of the fluid with larger time steps. In addition, an interfacial flux correction is applied to maintain the conservative property. The present algorithm has be coupled with a wavelet-based adaptive multi-resolution (MR) algorithm to achieve additional computational efficiency. A number of numerical tests indicate that the accuracy of the results obtained by the present method is comparable to of the original costly method, with a significant speedup. The speedup increases with the dimensions and resolution, which indicates its applications in 3D high resolution simulations of multiphase flows. (C) 2020 Elsevier Inc. All rights reserved.

关键词： Sharp-interface method Multiphase flows acceleration algorithm Multi-resolution

来源：评论

学校读者我要写书评

暂无评论

DESIGN AND APPLICATION OF BOUNDING VOLUME HIERARCHY COLLISION DETECTION algorithm BASED ON VIRTUAL SPHERE

引用

JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY 2019年第7期19卷

作者： Wang, Monan Chen, Shaoyong Yang, Qiyou Harbin Univ Sci & Technol Digital Med Inst Harbin 150080 Heilongjiang Peoples R China

The result of collision detection is closely related to the further deformation or cutting action of soft tissue. In order to further improve the efficiency and stability of collision detection, in this paper, a collision detection algorithm of bounding volume hierarchy based on virtual sphere was proposed. The proposed algorithm was validated and the results show that the detection efficiency of the bounding volume hierarchy algorithm based on virtual sphere is higher than that of the serial hybrid bounding volume hierarchy algorithm and the parallel hybrid bounding volume hierarchy algorithm. Different collision detection algorithms were tested and the results show that the collision detection algorithm based on virtual sphere has high detection efficiency and good stability. As the number of triangular patches increased, the advantage was more and more obvious. Finally, the proposed algorithm was applied to two large and medium-sized virtual scenes to implement the collision detection between the vastus lateralis muscle, thigh and surgical instrument. Based on the virtual sphere, the collision detection algorithm of bounding volume hierarchy can implement efficient and stable collision detection in a virtual surgery system. Meanwhile, the algorithm can be combined with other acceleration algorithms (such as the multithread acceleration algorithm) to further improve detection efficiency.

关键词： Virtual surgery collision detection bounding volume hierarchy acceleration algorithm

来源：评论

学校读者我要写书评

暂无评论

A practical two-term acceleration algorithm for linear systems

引用

NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS 2012年第3期19卷 571-583页

作者： Wang, Chuan-Long Meng, Guo-Yan Taiyuan Normal Univ Dept Math Taiyuan 030012 Shanxi Province Peoples R China Xinzhou Normal Univ Dept Comp Xinzhou 034000 Shanxi Province Peoples R China

In this paper, a practical two-term acceleration algorithm is proposed, the interval of the parameter which guarantees the convergence of the acceleration algorithm is analyzed in detail. Further, the acceleration ratio of the new acceleration algorithm is obtained in advance. The new acceleration algorithm is less sensitive to the parameter than the Chebyshev semi-iterative method. Finally, some numerical examples show that the accelerated algorithm is effective. Copyright (c) 2011 John Wiley & Sons, Ltd.

关键词： linear systems acceleration algorithm acceleration ratio convergence

来源：评论

学校读者我要写书评

暂无评论

FastBTM: Reducing the sampling time for biterm topic model

引用

KNOWLEDGE-BASED SYSTEMS 2017年 132卷 11-20页

作者： He, Xingwei Xu, Hua Li, Jia He, Liu Yu, Linlin Tsinghua Univ Dept Comp Sci & Technol State Key Lab Intelligent Technol & Syst Tsinghua Natl Lab Informat Sci & Technol Beijing 100084 Peoples R China Beijing Univ Posts & Telecommun Beijing 100876 Peoples R China Shanghai Jiao Tong Univ Shanghai 200240 Peoples R China

Due to the popularity of social networks, such as microblogs and Twitter, a vast amount of short text data is created every day. Much recent research in short text becomes increasingly significant, such as topic inference for short text. Biterm topic model (BTM) benefits from the word co-occurrence patterns of the corpus, which makes it perform better than conventional topic models in uncovering latent semantic relevance for short text. However, BTM resorts to Gibbs sampling to infer topics, which is very time consuming, especially for large-scale datasets or when the number of topics is extremely large. It requires 0(K) operations per sample for K topics, where K denotes the number of topics in the corpus. In this paper, we propose an acceleration algorithm of BTM, FastBTM, using an efficient sampling method for BTM, which converges much faster than BTM without degrading topic quality. FastBTM is based on Metropolis Hastings and alias method, both of which have been widely adopted in Latent Dirichlet Allocation (LDA) model and achieved outstanding speedup. Our FastBTM can effectively reduce the sampling complexity of biterm topic model from 0(K) to 0(1) amortized time. We carry out a number of experiments on three datasets including two short text datasets, Tweets2011 Collection dataset and Yahoo! Answers dataset, and one long document dataset, Enron dataset. Our experimental results show that when the number of topics K increases, the gap in running time speed between FastBTM and BTM gets especially larger. In addition, our FastBTM is effective for both short text datasets and long document datasets. (C) 2017 Elsevier B.V. All rights reserved.

关键词： BTM Topic model Alias method Metropolis-Hastings acceleration algorithm

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：