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YOLO-CORE: Contour Regression for Efficient Instance Segmentation

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Machine Intelligence Research 2023年第5期20卷 716-728页

作者： Haoliang Liu Wei Xiong Yu Zhang School of Computer Science and Engineering and the Key Laboratory of Computer Network and Information Integration(Ministry of Education) Southeast UniversityNanjing 211189China

Instance segmentation has drawn mounting attention due to its significant utility.However,high computational costs have been widely acknowledged in this domain,as the instance mask is generally achieved by pixel-level labeling.In this paper,we present a conceptually efficient contour regression network based on the you only look once(YOLO)architecture named YOLO-CORE for instance segmentation.The mask of the instance is efficiently acquired by explicit and direct contour regression using our designed multiorder constraint consisting of a polar distance loss and a sector loss.Our proposed YOLO-CORE yields impressive segmentation performance in terms of both accuracy and speed.It achieves 57.9%AP@0.5 with 47 FPS(frames per second)on the semantic boundaries dataset(SBD)and 51.1%AP@0.5 with 46 FPS on the COCO dataset.The superior performance achieved by our method with explicit contour regression suggests a new technique line in the YOLO-based image understanding field.Moreover,our instance segmentation design can be flexibly integrated into existing deep detectors with negligible computation cost(65.86 BFLOPs(billion float operations per second)to 66.15 BFLOPs with the YOLOv3 detector).

关键词： Computer vision instance segmentation object shape prediction contour regression polar distance.

Effect of morphological gene mutation and decay on energy dissipation behaviour of granular soils

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第4期24卷 303-318页

作者： Wei Xiong Qi-min ZHANG Jian-feng WANG Department of Architecture and Civil Engineering City University of Hong KongHong KongChina Shenzhen Research Institute of City University of Hong Kong Shenzhen 518057China

In this paper,the X-ray micro-computed tomography(X-rayμCT),spherical harmonical-based principal component analysis(SH-PCA),and discrete element method(DEM)were incorporated to generate virtual samples with morphological gene mutation at different length scales.All samples were subjected to axial compression and constant confining stress.The effects of multiscale particle morphology on the stress-strain and energy storage/dissipation responses of granular soils were investigated.It is found that:(a)the effects of particle morphology on the initial stiffness,stress-strain,volumetric strain,and frictional energy dissipation behaviours are more pronounced for looser samples than for denser ones;(b)among different length scales,the particle morphology at the local roundness-level outperforms the one at the general form-level in dictating the macro-scale responses of granular soils;(c)the energy dissipation of a granular assemblage is a result of competition between particle morphology and initial void ratio.

关键词： X-ray micro-computed tomography(X-rayμCT) Spherical harmonic analysis(SHA) Discrete element method(DEM) Morphological gene mutation Energy dissipation

The Logarithmic Capacitary Minkowski Problem for Polytopes

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Acta Mathematica Sinica,English Series 2022年第2期38卷 406-418页

作者： Ge xiong Jia Wei Xiong School of Mathematical Sciences Tongji UniversityShanghai 200092P.R.China School of Mathematics and Statistics Ningbo UniversityNingbo 315211P.R.China

The logarithmic capacitary Minkowski problem asks for necessary and sufficient conditions on a finite Borel measure on the unit sphere so that it is the logarithmic capacitary measure of a convex body.This article com... 详细信息

关键词： Minkowski problem capacity polytope general position

Uncertainty quantification and composition optimization for alloy additive manufacturing through a CALPHAD-based ICME framework

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npj Computational Materials 2020年第1期6卷 96-106页

作者： Xin Wang Wei Xiong Physical Metallurgy and Materials Design Laboratory Department of Mechanical Engineering and Materials ScienceUniversity of PittsburghPittsburghPA 15261USA

During powder production,the pre-alloyed powder composition often deviates from the target composition leading to undesirable properties of additive manufacturing(AM)components.Therefore,we developed a method to perform high-throughput calculation and uncertainty quantification by using a CALPHAD-based ICME framework(CALPHAD:calculations of phase diagrams,ICME:integrated computational materials engineering)to optimize the composition,and took the high-strength low-alloy steel(HSLA)as a case study.We analyzed the process–structure–property relationships for 450,000 compositions around the nominal composition of HSLA-115.Properties that are critical for the performance,such as yield strength,impact transition temperature,and weldability,were evaluated to optimize the composition.With the same uncertainty as to the initial composition,and optimized average composition has been determined,which increased the probability of achieving successful AM builds by 44.7%.The present strategy is general and can be applied to other alloy composition optimization to expand the choices of alloy for additive manufacturing.Such a method also calls for high-quality CALPHAD databases and predictive ICME models.

关键词： alloy steel additive

Sliding Dynamics of Slide-Ring Polymers Based on the Bead-Spring Model

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Chinese Journal of Polymer Science 2023年第9期41卷 1410-1424,I0007页

作者： Zhong-Qiang xiong wei Yu Advanced Rheology Institute Department of Polymer Science and EngineeringState Key Laboratory for Metal Matrix Composite MaterialsShanghai Jiao Tong UniversityShanghai200240China

Understanding the sliding dynamics is critical for developing rotaxane-based mechanically interlocked polymers.In this work,we studied the sliding behavior of a sliding ring and its influence on the dynamics of attached polymer chains based on the heterogeneous beadspring model.The sliding constraint was treated as direction-related confinement with the heterogeneous friction coefficient and constraint intensity.The relaxation spectrum,the diffusion dynamics,and the sliding dynamics under/after drag were studied for typical sliding chain topologies,namely,the sliding dangling chain,the constraint sliding chain,and the sliding strand.Compared with the non-sliding chains(such as the free chain,the dangling chain,and the network strand),the slide of one or two chain ends induces an additional slow process in the transition from the Rouse-type behavior to the long-time terminal behavior.The effect of the sliding-related process on the diffusion of specific chain segments relies on the chain topology.The slow sliding relaxation process is also observed in the sliding process during and after chain deformation,whose characteristic time is at least three times the terminal relaxation time of the free chain with the same length,and will increase with the friction coefficient(i.e.,the interaction)between the ring and the polymer axial.The results of this work will benefit the understanding of the sliding dynamics in experiments.

关键词： Sliding chain Bead-spring model Heterogeneity Diffusion Mean conformation

Manipulation of invisible cloaking in PT-symmetric thermoacoustic dimer

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 136-141页

作者： Haixiao Zhang Bolun Hu Wei Xiong Ying Cheng Xiaojun Liu Department of Physics MOE Key Laboratory of Modern AcousticsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of Electrical and Information Engineering Changzhou Institute of TechnologyChangzhou 213032China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Making the propagation of sound waves immune to interference from obstacles with high transmission efficiency is a long-term pursuit in acoustic science and engineering.Recent proposal pointed out that perfect transmission through obstacles can be achieved by deploying a bulky gain-loss distribution in parity-time(PT)symmetry.Here we demonstrate a modified methodology to achieve the extraordinary physical property of acoustic cloaking accompanied by perfect transmission at the exceptional points(EPs).Systematically probing reveals two complementary solutions of EPs corresponding to acoustic cloaking,in the system composed of an equivalent medium slab sandwiched by a pair of PT-symmetric admittance metasurfaces.To model the crucial acoustic gains that are not present in nature,we employ actively controlled ultra-thin carbon nanotube dimer films to mimic admittance metasurfaces perfectly via thermoacoustic effect,and manipulate acoustic cloaking over a wide frequency band in experiments.This divergent strategy releases restrictions on the operating frequency,shape and size of the obstacle,which can be applied to acoustic sensing,directional imaging,and other related wave disciplines.

关键词： acoustic cloaking PT-symmetric metasurfaces thermoacoustic carbon nanotube(CNT)dimer

Structure-Property Relationship Analysis of D-Penicillamine-Derivedβ-Polythioesters with Varied Alkyl Side Groups

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高分子科学:英文版 2023年第10期41卷 1555-1562页

作者： Chun-Yan Lyu Wei Xiong Er-Qiang Chen Hua Lu Beijing National Laboratory for Molecular Sciences Center for Soft Matter Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

The ring-opening polymerization of heterocyclic monomers and the reversed ring-closing depolymerization of corresponding polymers with neutral thermodynamics are broadly explored to establish a circular economy of next-generation plastics.Polythioesters(PTEs),analogues of polyesters,are emerging materials for this purpose due to their high refractive index,high crystallinity,dynamic property and responsiveness.In this work,we synthesize and polymerize a series of D-penicillamine-derivedβ-thiolactones(NRPenTL)with varied side chain alkyl groups,and study the structure-property relationship of the resulting polymers.The obtained PTEs exhibit tunable glass transition temperature in a wide range of 130–50℃,and melting temperature of 90–105℃.In addition,copolymerizations of monomers with different side chains are effective in modulating material properties.The obtained homo and copolymers can be fully depolymerized to recycle monomers.This work provides a robust molecular platform and detailed structure-property relationship of PTEs with potential of achieving sustainable plastics.

关键词： β-Polythioesters Geminal dimethyl Structure-property relationship Chemical recycling to monomers

Effect of reclaimed water effluent on bacterial community structure in the Typha angustifolia L. rhizosphere soil of urbanized riverside wetland, China

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Journal of Environmental Sciences 2017年第5期29卷 58-68页

作者： Xingru Huang Wei Xiong wei Liu Xiaoyu Guo College of Resources Environment and Tourism Capital Normal University Beijing 100048 China Belting Municipal Key Laboratory of Resources Environment and GIS Beijing 100048 China Urban Environmental Processes and Digital Modeling Laboratory Beijing 100048 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

In order to evaluate the impact of reclaimed water on the ecology of bacterial communities in the Typha angustifolia L. rhizosphere soil, bacterial community structure was investigated using a combination of terminal restriction fragment length polymorphism and 16S rRNA gene clone library. The results revealed significant spatial variation of bacterial communities along the river from upstream and downstream. For example, a higher relative abundance of γ-Proteobacteria, Firmicutes, Chloroflexi and a lower proportion of β-Proteobacteria and ε-Proteobacteria was detected at the downstream site compared to the upstream site. Additionally, with an increase of the reclaimed water interference intensity, the rhizosphere bacterial community showed a decrease in taxon richness, evenness and diversity. The relative abundance of bacteria closely related to the resistant of heavy-metal was markedly increased, while the bacteria related for carbon/nitrogen/phosphorus/sulfur cycling wasn＇t strikingly changed. Besides that, the pathogenic bacteria markedly increased in the downstream rhizosphere soil since reclaimed water supplement, while the possible plant growth-promoting rhizobacteria obviously reduced in the downstream sediment. Together these data suggest cause and effect between reclaimed water input into the wetland, shift in bacterial communities through habitat change, and alteration of capacity for biogeochemical cycling of contaminants.

关键词： Reclaimed water T-RFLP 16S rRNA gene clone library Bacterial community structure

Depression behaviors of N-thiourea-maleamic acid and its adsorption mechanism on galena in Mo-Pb flotation separation

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International Journal of Mining Science and Technology 2022年第1期32卷 181-189页

作者： Liang Lu Wei Xiong Yangge Zhu Xingrong Zhang Yongxing Zheng State Key Laboratory of Mineral Processing Beijing 102628China BGRIMM Technology Group Beijing 102628China China-South Africa Belt and Road Joint Laboratory on Sustainable Exploration and Utilization of Mineral Resources Beijing 102628China State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming 650093China

In present study,a novel organic depressant N-thiourea-maleamic acid(TMA)was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores.The depression behaviors of TMA were tested through flotation experiments.A wider separation window for single minerals over 90.0%was obtained at 30.0 mg/L TMA,confirming that TMA could depress galena significantly,while effected molybdenite floatability slightly.An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores.The adsorption mechanism on galena was revealed by UV-Vis spectra,zeta potential tests,Fourier transform infrared spectroscopy(FT-IR)analysis,contact angle tests and X-ray photoelectron spectroscopy(XPS)analysis.The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36°to 57.8°with 30.0 mg/L TMA depressant,inferring that TMA had adsorbed on galena surface.The analysis results of UV-Vis spectra,FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure,while the carboxyl group played a role of hydrophilicity.

关键词： Molybdenite Galena TMA Separation Adsorption