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Accelerating fully resolved simulation of particle-laden flows on heterogeneous computer architectures

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Particuology 2023年第10期81卷 25-37页

作者： Kuang ma maoqiang jiang Zhaohui Liu State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan430074China Department of Mechanical Engineering National University of Singapore117575Singapore

An efficient computing framework,namely PFlows,for fully resolved-direct numerical simulations of particle-laden flows was accelerated on NVIDIA General Processing Units(GPUs)and GPU-like accelerator(DCU)cards.The framework is featured as coupling the lattice Boltzmann method for fluid flow with the immersed boundary method for fluid-particle interaction,and the discrete element method for particle collision,using two fixed Eulerian meshes and one moved Lagrangian point mesh,respectively.All the parts are accelerated by a fine-grained parallelism technique using CUDA on GPUs,and further using HIP on DCU cards,i.e.,the calculation on each fluid grid,each immersed boundary point,each particle motion,and each pair-particle collision is responsible by one computer thread,respectively.Coalesced memory accesses to LBM distribution functions with the data layout of Structure of Arrays are used to maximize utilization of hardware bandwidth.Parallel reduction with shared memory for data of immersed boundary points is adopted for the sake of reducing access to global memory when integrate particle hydrodynamic force.MPI computing is further used for computing on heterogeneous architectures with multiple CPUs-GPUs/DCUs.The communications between adjacent processors are hidden by overlapping with calculations.Two benchmark cases were conducted for code validation,including a pure fluid flow and a particle-laden flow.The performances on a single accelerator show that a GPU V100 can achieve 7.1–11.1 times speed up,while a single DCU can achieve 5.6–8.8 times speed up compared to a single Xeon CPU chip(32 cores).The performances on multi-accelerators show that parallel efficiency is 0.5–0.8 for weak scaling and 0.68–0.9 for strong scaling on up to 64 DCU cards even for the dense flow(φ=20%).The peak performance reaches 179 giga lattice updates per second(GLUPS)on 256 DCU cards by using 1 billion grids and 1 million particles.At last,a large-scale simulation of a gas-solid flow with 1.6 billion grids and 1.6 million particles wa

关键词： Lattice Boltzmann method Immersed boundary method Particle-ladenflows Heterogeneous acceleration General Processing Units

Contrastive Learning for Blind Super-Resolution via A Distortion-Specific Network

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IEEE/CAA Journal of Automatica Sinica 2023年第1期10卷 78-89页

作者： Xinya Wang Jiayi ma Junjun jiang the Electronic Information School Wuhan UniversityWuhan 430072China IEEE the School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China

Previous deep learning-based super-resolution(SR)methods rely on the assumption that the degradation process is predefined(e.g.,bicubic downsampling).Thus,their performance would suffer from deterioration if the real degradation is not consistent with the assumption.To deal with real-world scenarios,existing blind SR methods are committed to estimating both the degradation and the super-resolved image with an extra loss or iterative scheme.However,degradation estimation that requires more computation would result in limited SR performance due to the accumulated estimation errors.In this paper,we propose a contrastive regularization built upon contrastive learning to exploit both the information of blurry images and clear images as negative and positive samples,respectively.Contrastive regularization ensures that the restored image is pulled closer to the clear image and pushed far away from the blurry image in the representation space.Furthermore,instead of estimating the degradation,we extract global statistical prior information to capture the character of the distortion.Considering the coupling between the degradation and the low-resolution image,we embed the global prior into the distortion-specific SR network to make our method adaptive to the changes of distortions.We term our distortion-specific network with contrastive regularization as CRDNet.The extensive experiments on synthetic and realworld scenes demonstrate that our lightweight CRDNet surpasses state-of-the-art blind super-resolution approaches.

关键词： Blind super-resolution contrastive learning deep learning image super-resolution(SR)

Loop Closure Detection via Locality Preserving matching With Global Consensus

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IEEE/CAA Journal of Automatica Sinica 2023年第2期10卷 411-426页

作者： Jiayi ma Kaining Zhang Junjun jiang IEEE the Electronic Information School Wuhan UniversityWuhan 430072China the School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China

A critical component of visual simultaneous localization and mapping is loop closure detection(LCD),an operation judging whether a robot has come to a pre-visited area.Concretely,given a query image(i.e.,the latest view observed by the robot),it proceeds by first exploring images with similar semantic information,followed by solving the relative relationship between candidate pairs in the 3D space.In this work,a novel appearance-based LCD system is proposed.Specifically,candidate frame selection is conducted via the combination of Superfeatures and aggregated selective match kernel(ASMK).We incorporate an incremental strategy into the vanilla ASMK to make it applied in the LCD task.It is demonstrated that this setting is memory-wise efficient and can achieve remarkable performance.To dig up consistent geometry between image pairs during loop closure verification,we propose a simple yet surprisingly effective feature matching algorithm,termed locality preserving matching with global consensus(LPM-GC).The major objective of LPM-GC is to retain the local neighborhood information of true feature correspondences between candidate pairs,where a global constraint is further designed to effectively remove false correspondences in challenging sceneries,e.g.,containing numerous repetitive structures.Meanwhile,we derive a closed-form solution that enables our approach to provide reliable correspondences within only a few milliseconds.The performance of the proposed approach has been experimentally evaluated on ten publicly available and challenging datasets.Results show that our method can achieve better performance over the state-of-the-art in both feature matching and LCD tasks.We have released our code of LPM-GC at https://***/jiayi-ma/LPM-GC.

关键词： Feature matching locality preserving matching loop closure detection SLAM

machine learning accelerated DFT research on platinum-modified amorphous alloy surface catalysts

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Chinese Chemical Letters 2023年第5期34卷 645-649页

作者： Xi Zhang Kangpu Li Bo Wen Jiang Ma Dongfeng Diao Institute of Nanosurface Science and Engineering Guangdong Provincial Key Laboratory of Micro/NanoShenzhen UniversityShenzhen 518060China College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China Research Center of Medical Plasma Technology Shenzhen UniversityShenzhen 518060China

Pt-modified amorphous alloy(Pt@PdNiCuP)catalyst exhibits excellent electro-catalytic activity and high experimental durability for hydrogen evolution reaction(HER).However,the physical origin of the catalytically active remains unclear.In this paper,we constructed a distance contribution descriptor(DCD)for the feature engineering of machine learning(ML)potential,and calculated the Gibbs free energies(ΔGH)of 46,000*H binding sites on the Pt@Pd Ni Cu P surface by ML-accelerated density functional theory(DFT).The relationship betweenΔGHand DCD revealed that in the H-Pt distance region of 2.0-2.5 A where the parabolic tail and disordered scatters coexist,the H-metal bonding configuration is mainly the bridge-or hollow-bonding type.The contribution analysis of DCD indicates that the joint effect of Pt,Pd and Ni atoms determines the catalytical behavior of amorphous alloy,which agrees well with experimental results.By counting atomic percentages in different energy intervals,we obtained the atomic ratio for the best catalytic performance(Pt:Pd:Ni:Cu:P=0.33:0.17:0.155:0.16:0.185).Projected density of states(PDOS)show that H 1s orbital,Pt 5d orbital,and Pd 4d orbital form a bonding state at-2 e V.These results provide new ideas for designing more active amorphous alloy catalysts.

关键词： Hydrogen evolution reaction Amorphous alloy Density functional theory machine learning

Molecular mechanism analysis of Miao medicine Jinwujiangu decoction(金乌健骨方) in treating osteoarthritis based on a network pharmacology approach

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Journal of Traditional Chinese Medicine 2022年第4期42卷 576-585页

作者： jiang Zong YAO Xiaoling ma Wukai TANG Fang Department of Rheumatology the Second Affiliated Hospital of Guizhou University of Traditional Chinese MedicineGuiyang 550002China Department of Traditional Chinese Medicine Longhua District Central HospitalShenzhen 518110China

OBJECTIVE:To investigate molecular mechanisms of Jinwujiangu decoction(金乌健骨方,JWJG)in treating osteoarthritis(OA)using network pharmacology analysis.METHODS:Principal active compounds of JWJG were screened out via the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)and BATmaN-TCM,and potential targets for OA treatment were identified through Online Mendelian Inheritance in man(OMIM)and Gene Cards databases.The JWJG network diagrams of both principal chemical compound-action targets and OA treatment target-OA disease were constructed applying the Cytoscape 3.7.2 software.The diagram of protein-protein interaction network was plotted for core analysis.Meanwhile,the common targets and relevant signaling pathways involved in both networks were analyzed using the Gene Ontology function analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment.The predicted results were ultimately verified through animal experiments.RESULTS:Effects of JWJG were indicated in acting on key targets interleukin-6,insulin,protein kinase B,glyceraldehyde-3-phosphate dehydrogenase,and mitosis-specific MRE11-RAD50-NBS1 associated protein by regulating signaling pathways of phosphoinositide 3-kinase-protein kinase B,mitogen-activated protein kinases,tumor necrosis factor,and colorectal cancer.Meanwhile,it inhibited the over-activation of signaling pathways and the release of inflammatory factors in OA treatment.Following a signaling pathway analysis utilizing network pharmacology technique,it was demonstrated that JWJG could treat OA through the Wnt/β-catenin signaling pathway verified by animal experiments.CONCLUSIONS:The present study preliminarily analyzed the pharmacological mechanism of JWJG in treating OA on a network pharmacology approach and provided a great theoretical significance for clinical application.

关键词： osteoarthritis network pharmacology targets Jinwujiangu decoction

Role of dietary amino acids and microbial metabolites in the regulation of pig intestinal health

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Animal Nutrition 2022年第2期9卷 1-6页

作者： Yong ma Xuebing Han Jun Fang Hongmei jiang College of Bioscience and Biotechnology Hunan Agricultural UniversityHunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and PoultryChangsha410128China

With the rapid development of sequencing technology,research on pigs has focused on intestinal microbes.Accumulating evidence suggests that the metabolites of intestinal microbes are the key medium for interactions between microbes and the host.Amino acid metabolism is involved in the growth and immune processes of pigs.The gut microbes of pigs are heavily involved in the metabolism of amino acids in their hosts.Here,we review the latest relevant literature.Research findings show that microbial metabolites,such as indoles,short-chain fatty acids,and ammonia,play a key role in gut health.Moreover,we summarize the effects of amino acids on the structure of the gut microbial community and the metabolism of amino acids by pig gut microbes.Evidence shows that microbial amino acid metabolites act as signal molecules in the intestine and play an important role in the intestinal health of pigs.

关键词： Pig Amino acid Intestinal microbe Metabolite

A Modified Bi-Directional Evolutionary Structural Optimization Procedure with Variable Evolutionary Volume Ratio Applied to Multi-Objective Topology Optimization Problem

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Computer Modeling in Engineering & Sciences 2023年第4期135卷 511-526页

作者： Xudong jiang Jiaqi ma Xiaoyan Teng School of Mechanical and Power Engineering Harbin University of Science and TechnologyHarbin150080China College of Mechanical and Electrical Engineering Harbin Engineering UniversityHarbin150001China

Natural frequency and dynamic stiffness under transient loading are two key performances for structural design related to automotive,aviation and construction industries.This article aims to tackle the multi-objective topological optimization problem considering dynamic stiffness and natural frequency using modified version of bi-directional evolutionary structural optimization(BESO).The conventional BESO is provided with constant evolutionary volume ratio(EVR),whereas low EVR greatly retards the optimization process and high EVR improperly removes the efficient elements.To address the issue,the modified BESO with variable EVR is introduced.To compromise the natural frequency and the dynamic stiffness,a weighting scheme of sensitivity numbers is employed to form the Pareto solution space.Several numerical examples demonstrate that the optimal solutions obtained from the modified BESO method have good agreement with those from the classic BESO method.Most importantly,the dynamic removal strategy with the variable EVR sharply springs up the optimization process.Therefore,it is concluded that the modified BESO method with variable EVR can solve structural design problems using multi-objective optimization.

关键词： Bi-directional evolutionary structural optimization variable evolutionary volume ratio multi-objective optimization weighted sum topology optimization

Loop Closure Detection With Reweighting Net VLAD and Local Motion and Structure Consensus

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IEEE/CAA Journal of Automatica Sinica 2022年第6期9卷 1087-1090页

作者： Kaining Zhang Jiayi ma Junjun jiang Electronic Information School Wuhan UniversityWuhan 430072China IEEE School of Computer Science and Technology Harbin Institute of TechnologyHarbin 150001China

Dear Editor,Loop closure detection(LCD)is an important module in simultaneous localization and mapping(SLAM).In this letter,we address the LCD task from the semantic aspect to the geometric one.To this end,a network termed as AttentionNetVLAD which can simultaneously extract global and local features is proposed.It leverages attentive selection for local features,coupling with reweighting the soft assignment in NetVLAD via the attention map for global features.Given a query image,candidate frames are first identified coarsely by retrieving similar global features in the database via hierarchical navigable small world(HNSW).As global features mainly summarize the semantic information of images and lead to compact representation,information about spatial arrangement of visual elements is lost.

关键词： Net hierarchical arrangement

Engineering the interface of porous CoMoO_(3)nanosheets with Co_(3)Mo nanoparticles for high-performance electrochemical overall water splitting

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Journal of materials Science & Technology 2023年第6期137卷 184-192页

作者： Haibin ma Xuejing Yang Zhili Wang Qing jiang Key Laboratory of Automobile materials Ministry of Educationand School of Materials Science and EngineeringJilin UniversityChangchun 130022China

The design of high-performance electrocatalysts for alkaline water splitting is of significant importance for the development of a sustainable hydrogen economy.Herein,heterostructured Co_(3)Mo nanoparti-cles/porous CoMoO_(3)nanosheets(Co_(3)Mo/CoMoO_(3)NPSs)were constructed for alkaline water splitting by annealing CoMoO x nanosheets under controlled atmospheres.Thanks to its interfacial electronic structure and increased electrochemical active area,Co_(3)Mo/CoMoO_(3)NPSs exhibit impressive hydrogen evolution reaction(HER)activity with an overpotential of 334 mV at 1000 ma cm^(-2) and a Tafel slope of 46.4 mV per decade in 1.0 M KOH,which outperforms Pt/C catalyst(621 mV and 74.7 mV per decade).Density functional theory calculations illustrate the electron transfer from Co_(3)Mo to CoMoO_(3)at the interfaces,where electron accumulation on CoMoO_(3)favors the dissociation of H_(2)O molecule,and electron-deficient Co atoms in Co_(3)Mo have optimized H∗absorption energy for HER.The Co_(3)Mo/CoMoO_(3)NPSs also exhibit higher oxygen evolution reaction activity than the RuO_(2)catalyst.Moreover,the water electrolyzer us-ing Co_(3)Mo/CoMoO_(3)NPSs as both cathode and anode only requires 1.59 V to deliver a current density of 100 ma cm^(-2)in 1.0 M KOH,which outperforms benchmark Pt/C||RuO_(2)electrodes couple with 1.69 V to reach the same current density,providing great potential for large-scale applications.

关键词： Interface engineering Heterostructures Interfacial electronic structure Hydrogen evolution reaction Overall water splitting