检索结果-内蒙古大学图书馆

2023 International Conference on High Performance Computing in Asia-Pacific Region Workshops, HPC Asia 2023

作者： Kikuchi, Kohei Fujita, Norihisa Kobayashi, Ryohei Boku, Taisuke Master's Program in Computer Science Degree Programs in Systems and Information Engineering Graduate School of Science and Technology University of Tsukuba Tsukuba Japan Center for Computational Sciences University of Tsukuba Tsukuba Japan

ISBN: (纸本)9781450399890

In the high-performance computing domain, Field programmable Gate Array (FPGA) is a novel accelerator that exhibits high flexibility and performance characteristics distinct from other accelerators such as the Graphics Processing Unit (GPU). Recent advanced high-end FPGA is equipped with multiple channels of high speed optical link up to 100Gbps performance for each. This is a crucial feature when we construct PC clusters with FPGAs as accelerators, however it is not easy to utilize from user kernels because this feature is implemented in low level and simple direct communication between neighboring FPGAs. In order to provide the communication feature between FPGAs for accelerated PC clusters, we developed a communication system named CIRCUS which implies a user-friendly API from OpenCL and is equipped with routing function over multi-hop communication on multi-dimensional torus network of FPGAs. However, current CIRCUS only provides a point-to-point communication between source and destination FPGAs. In ordinary parallel processing environment such as MPI, the user program the message passing with various collective communication functions for parallel algorithm, for instance Allreduce, Allgather, etc. In this paper, we implement the collective communication function over CIRCUS for user-friendly programming of ordinary parallel algorithms on FPGAs. As the first target, we implement Allreduce function which is the most essential and important function. The paper describes the CIRCUS system briefly followed by the design, implementation and preliminary performance evaluation on Intel Stratix10 FPGAs. © 2023 ACM.

关键词： Field programmable gate arrays (FPGA)

来源：评论

学校读者我要写书评

暂无评论

Influence of conformational change of chain unit on the intrinsic negative thermal expansion of polymers

引用

Chinese Chemical Letters 2021年第4期32卷 1515-1518页

作者： Qiangsheng Sun Ke Jin Yuhui Huang Jia Guo Thanyada Rungrotmongkol Phornphimon Maitarad Changchun Wang State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science Fudan UniversityShanghai 200433.China Biocatalyst and Environmental Biotechnology Research Unit Department of BiochemistryFaculty of Science and Program in Bioinformatics and Computational BiologyGraduate SchoolChulalongkom UniversityBangkok 10330Thailand Research Center of Nano Science and Technology Shanghai UniversityShanghai 200444China

Negative thermal expansion(NTE) behavior has roused wide interest for the control of thermomechanical properties of functional *** NTE behaviors have been found in kinds of compounds,it remains challenging for polymers to achieve intrinsic NTE *** this work,we systematically studied the conformational change of dibenzocyclooctadiene(DBCOD) derivatives between chair(C) and twist-boat(TB) forms based on density-functional theo ry(DFT) calculations,and found clear evidence of the relationship between the structure of DBCOD units and the thermal contraction behavior of the related *** order to obtain the polymer with NTE property,two conditions should be met for the thermal contracting DBCOD related units as follows:(i) the TB conformation can turn into C conformation as the temperature increases,and(ii) the volume of C conformation is smaller than that of TB *** rule should offer a guidance to exploration of the new intrinsic NTE polymers in the future.

关键词： Negative thermal expansion Conformational change Polyarylamides Density-functional theory Dibenzocyclooctadiene

来源：评论

学校读者我要写书评

暂无评论

Scaled-up synthesis of defect-rich layered double hydroxide monolayers without organic species for efficient oxygen evolution reaction

引用

Green Energy & Environment 2022年第5期7卷 975-982页

作者： Haoyuan Chi Jingwen Dong Tian Li Sha Bai Ling Tan Jikang Wang Tianyang Shen Guihao Liu Lihong Liu Luyi Sun Yufei Zhao Yu-Fei Song State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing100875China Polymer Program Institute of Materials Science and Department of Chemical&Biomolecular EngineeringUniversity of ConnecticutStorrsConnecticut06269USA Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029China

The scaled-up synthesis of organic-free monolayer nanomaterials is highly desirable,especially in obtaining green energy by *** this study,a method for the scaled-up synthesis of the series of monolayer layered double hydroxides(LDHs)without the addition of organic solvents is reported via the separate nucleation and aging steps *** resulting monolayer LDHs with the thicknesses of less than 1 nm showed a narrow thickness distribution.X-ray absorption fine-structure revealed that monolayer NiFe-LDH nanosheets have a number of oxygen and metal vacancies *** a practical application,monolayer NiFe-LDH nanosheets containing defects showed an enhanced electrocatalytic water oxidation activity compared with that of bulk *** functional theory calculations uncovered that excellent catalytic activity is attributed to vacancies *** proposed method is an economical and universally applicable strategy for the scaled-up production of monolayer LDHs.

关键词： process synthesis monolayer

来源：评论

学校读者我要写书评

暂无评论

Semi-analytical finite element method applied for characterizing micropolar fibrous composites

引用

Applied Mathematics and Mechanics(English Edition) 2024年第12期45卷 2147-2164页

作者： J.A.OTERO Y.ESPINOSA-ALMEYDA R.RODRIGUEZ-RAMOS J.MERODIO School of Engineering and Sciences Monterrey Institute of TechnologyEstado de Mexico 52926Mexico Institute of Engineering and Technology Autonomous University of Ciudad JuarezCiudad JuarezChihuahua 32310Mexico Postgraduate Program in Computational Modeling in Science and Technology Federal Fluminense UniversityRıo de Janeiro 27255-125Brazil Faculty of Mathematics and Computer Science University of HavanaLa Habana 10400Cuba Department of Mathematics Applied to ICT School of Informatics Systems EngineeringTechnical University of MadridMadrid 28031Spain

A semi-analytical finite element method(SAFEM),based on the two-scale asymptotic homogenization method(AHM)and the finite element method(FEM),is implemented to obtain the effective properties of two-phase fiber-reinforced composites(FRCs).The fibers are periodically distributed and unidirectionally aligned in a homogeneous *** framework addresses the static linear elastic micropolar problem through partial differential equations,subject to boundary conditions and perfect interface contact *** mathematical formulation of the local problems and the effective coefficients are presented by the *** local problems obtained from the AHM are solved by the FEM,which is denoted as the *** numerical results are provided,and the accuracy of the solutions is analyzed,indicating that the formulas and results obtained with the SAFEM may serve as the reference points for validating the outcomes of experimental and numerical computations.

关键词： semi-analytical approach fiber-reinforced composite(FRC) effective property finite element method(FEM) asymptotic homogenization method(AHM) micropolar elasticity

来源：评论

学校读者我要写书评

暂无评论

Fundamental elements of vector enhanced multivariance product representation

引用

AIP Conference Proceedings 2012年第1期1479卷 1998-2001页

作者： Berfin Kalay Metin Demiralp İstanbul Technical University Informatics Institute Computational Science and Engineering Program Maslak 34469 İstanbul Turkey İstanbul Technical University Informatics Institute Computational Science and Engineering Program Maslak 34469 İstanbul Turkey

A new version of High Dimensional Model Representation (HDMR) is presented in this work. Vector HDMR has been quite recently developed to deal with the decomposition of vector valued multivariate functions. It was an extension from scalars to vectors by possibly using matrix weights. However, that expansion is based on an ascending multivariance starting from a constant term via a set of appropriately imposed conditions which can be related to orthogonality in a conveniently chosen Hilbert space. This work adds more flexibility by introducing certain matrix valued univariate support functions. We assume weight matrices proportional to unit matrices. This work covers only the basic issues related to the fundamental elements of the new approach.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Simulation of the transient, compressible, gas-dynamic behavior of catalytic-combustion ignition in stagnation flows

Simulation of the transient, compressible, gas-dynamic behav...

引用

27th International Symposium on Combustion

作者： Raja, Laxminarayan L. Kee, Robert J. Petzold, Linda R. Engineering Division Colorado School of Mines Golden CO 80401 United States Computational Science and Engineering Program Department of Mechanical and Environmental Engineering University of California Santa Barbara Santa Barbara CA 93106 United States

This paper develops and uses a computation model to explore the transient ignition dynamics of catalytic combustion in a stagnation-flow configuration. The analysis considers the elementary heterogeneous chemistry associated with catalytic behavior at the surface. It also considers gas-dynamic effects in the boundary layer, including temporal and spatial pressure variations. The gas-dynamic effects are included through the axial momentum equation, which has been neglected in previous analyses of unsteady stagnation flows. In addition to the physical interpretation of ignition transients, the paper presents a mathematical and computational analysis and comparison of the constant-pressure and compressible stagnation-flow equations. The constant-pressure equations, as commonly formulated and used, are a system of differential-algebraic equations (DAE) that have an index greater than two. This high-index behavior is responsible for severe numerical difficulties in regions of fast transients or stringent numerical error control. This paper relaxes the constant-pressure assumption using a compressible-flow formulation, which extends the range of physical validity and reduces the index of the transient stagnation-flow problem while preserving stagnationflow "similarity.".

关键词： Ignition

来源：评论

学校读者我要写书评

暂无评论

High Resolution of City-Level Climate Simulation by GPU with Multi-physical Phenomena 18th

High Resolution of City-Level Climate Simulation by GPU with...

引用

18th IFIP WG 10.3 International Conference on Network and Parallel Computing, NPC 2021

作者： Watanabe, Koei Kikuchi, Kohei Boku, Taisuke Sato, Takuto Kusaka, Hiroyuki Master’s Program in Computer Science Graduate School of Systems and Information Engineering University of Tsukuba Tsukubashi Japan Center for Computational Sciences University of Tsukuba Tsukubashi Tennodi Japan

ISBN: (纸本)9783030935702

In this paper, we describe the Graphics Processing Unit (GPU) implementation of our City-LES code on detailed large eddy simulations, including the multi-physical phenomena on fluid dynamics, heat absorption and reflection by surface and building materials, cloud effects, and even sunlight effect. Because a detailed simulation involving these phenomena is required for analyses at the street level and several meters of resolution, the computation amount is enormous, and ordinary CPU computation cannot provide sufficient performance. Therefore, we implemented the entire code on GPU clusters with large-scale computing. We applied OpenACC coding to incrementally implement relatively easy programming and eliminate data transfers between the CPU and GPU memories. Based on this research, we determined that the elimination of data transfers is effective, even in the case where a part of the code execution on the GPU is slower than the CPU, owing to the absence of spatial parallelism. The objective of this study is to perform a complete climate simulation on a few square-kilometers field around the Tokyo Station, considering the finest resolution of the original highlighted area of the Marathon race in the Olympic Games Tokyo 2020. We successfully transferred the entire code to the GPU to provide approximately eight times the performance of CPU-only computation on multi-GPU per node with a large scale cluster. © 2022, IFIP International Federation for Information Processing.

关键词： Graphics processing unit

来源：评论

学校读者我要写书评

暂无评论

Hybrid optimization schemes for global optimization: Wing modeling of micro-aerial vehicles

Hybrid optimization schemes for global optimization: Wing mo...

引用

2010 DoD High Performance Computing Modernization program Users Group Conference, HPCMP UGC 2010

作者： Velázquez, Leticia Argáez, Miguel Sanchez, Reinaldo Ramirez, Carlos Hernandez, Miguel Culbreth, Matt Jameson, Antony Program in Computational Science University of Texas at El Paso El Paso TX United States Department of Aerospace Engineering Stanford University Palo Alto CA United States

ISBN: (纸本)9780769543925

In this paper, we present a parallel hybrid algorithm for solving global optimization problems that is based on the coupling of a stochastic global (Simultaneous-Perturbation Stochastic Approximation, Simulated Annealing, Genetic Algorithms) and a local method (Newton-Krylov Interior-Point) via a surrogate model. There exist several algorithms for finding approximate global solutions, but our technique will further guarantee that such solutions satisfy physical bounds of the problem. First, the Simultaneous-Perturbation Stochastic Approximation (SPSA) algorithm conjectures regions where a global solution may exist. Next, some data points from the regions are selected to generate a continuously differentiable surrogate model that approximates the original function. Finally, the Newton-Krylov Interior-Point (NKIP) algorithm is applied to the surrogate model subject to bound constraints for obtaining a feasible approximate global solution. The hybrid optimization code is being applied to Stanford's UFLO computational Fluid Dynamics (CFD) code. This code is used by the US Army High Performance Computing Research Center (AHPCRC) to develop flapping-and twisting-wing models for Micro Aerial Vehicles (MAV), hummingbird-sized airborne vehicles that can be used for sensing and surveillance. We present some preliminary numerical results of the large-scale high performance computing (HPC) hybrid optimization C code that is being run on the Department of Defense MANA machine from Maui, Hawaii. © 2011 IEEE.

关键词： Global optimization

来源：评论

学校读者我要写书评

暂无评论

Conduction heat transfer problem solution using the method of fundamental solutions with the dual reciprocity method

Conduction heat transfer problem solution using the method o...

引用

2005 ASME Summer Heat Transfer Conference, HT 2005

作者： Erdönmez, Cengiz Saygin, Hasan Institute of Informatics Computational Science and Engineering Program Istanbul Technical University Maslak Istanbul 34469 Turkey Institute of Energy Istabul Technical University Maslak Istanbul 34469 Turkey

ISBN: (纸本)0791847314

The method of fundamental solutions (MFS) is first proposed in 1964 by Kupradze and theoretical basis of this method is constructed at the end of 1980's. As a meshless method, no domain meshing is required for MFS. Fundamental solutions are used to solve problems without coping with the singularity on the boundary because of the fictitious boundary defined containing the domain of the problem. In this paper effectiveness of the MFS will be introduced by two test problem for the homogeneous and inhomogeneous modified helmholtz equations. Inhomogeneous terms are approximated by using the method of particular solutions through the dual reciprocity method. The conduction heat transfer problem is defined and transformed to the corresponding elliptic partial differential equation by using finite difference and the method of lines method which gives an inhomogeneous helmholtz equation. Then the problem is solved iteratively by using the MFS. Two test problem are solved by both the finite element method (FEM) and MFS and compared in the figures. It can be seen that as a meshless method, MFS gives very good results for the test problems. The thermal shock problem presented here also gives accurate solutions by using MFS and agrees well with the FEM solution. Copyright © 2005 by ASME.

关键词： Heat conduction

来源：评论

学校读者我要写书评

暂无评论

The location of Ti atom in sodium alanate: An ab initio spin-polarised study

The location of Ti atom in sodium alanate: An ab initio spin...

引用

作者： Du, A.J. Smith, Sean C. Lu, G.Q. Centre for Computational Molecular Science ARC Centre for Functional Nanomaterial University of Queensland Brisbane QLD 4072 Australia University of Queensland Australia Hydrogen Storage Systems Australia Department of Computational Molecular Science University of Queensland Australia Centre for Computational Molecular Science UQ Australia Computational Nanotecnnology Program ARC Centre for Functional Nanomaterials Australia Department of Chemical Engineering in Nanotechnology University of Queensland Australia ARC Centre for Functional Nanomaterials Australia Australian Academy of Technological Sciences and Engineering Australia

In this work, ab initio spin-polarised Density Functional Theory (DFT) calculations are performed to study the interaction of a Ti atom with a NaAlH4(001) surface. We confirm that an interstitially located Ti atom in the NaAlH4 subsurface is the most energetically favoured configuration as recently reported (Chem. Comm. (17) 2006, 1822). On the NaAlH4(001) surface, the Ti atom is most stable when adsorbed between two sodium atoms with an AlH4 unit beneath. A Ti atom on top of an Al atom is also found to be an important structure at low temperatures. The diffusion of Ti from the Al-top site to the Na-bridging site has a low activation barrier of 0.20 eV and may be activated at the experimental temperatures (∼323 K). The diffusion of a Ti atom into the energetically favoured subsurface interstitial site occurs via the Na-bridging surface site and is essentially barrierless. Copyright © 2007 Inderscience Enterprises Ltd.

关键词： Titanium

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：