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Towards optimized tensor code generation for deep learning on sunway many-core processor

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Frontiers of Computer Science 2024年第2期18卷 1-15页

作者： Mingzhen LI Changxi LIU Jianjin LIAO Xuegui ZHENG Hailong YANG Rujun SUN Jun XU Lin GAN Guangwen YANG Zhongzhi LUAN Depei QIAN State Key Laboratory of Software Development Environment Beijing 100191China School of Computer Science and Engineering Beihang UniversityBeijing 100191China National University of Singapore Singapore 119077Singapore State Key Laboratory of Mathematical Engineering and Advanced Computing Wuxi 214000China Science and Technology on Special System simulation Laboratory beijing simulation center Beijing 100854China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China

The flourish of deep learning frameworks and hardware platforms has been demanding an efficient compiler that can shield the diversity in both software and hardware in order to provide application *** the existing deep learning compilers,TVM is well known for its efficiency in code generation and optimization across diverse hardware *** the meanwhile,the Sunway many-core processor renders itself as a competitive candidate for its attractive computational power in both scientific computing and deep learning *** paper combines the trends in these two ***,we propose swTVM that extends the original TVM to support ahead-of-time compilation for architecture requiring cross-compilation such as *** addition,we leverage the architecture features during the compilation such as core group for massive parallelism,DMA for high bandwidth memory transfer and local device memory for data locality,in order to generate efficient codes for deep learning workloads on *** experiment results show that the codes generated by swTVM achieve 1.79x improvement of inference latency on average compared to the state-of-the-art deep learning framework on Sunway,across eight representative *** work is the first attempt from the compiler perspective to bridge the gap of deep learning and Sunway processor particularly with productivity and efficiency in *** believe this work will encourage more people to embrace the power of deep learning and Sunwaymany-coreprocessor.

关键词： sunway processor deep learning compiler code generation performance optimization

Material-SAM:Adapting SAM for Material XCT

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Computers, Materials & Continua 2024年第3期78卷 3703-3720页

作者： Xuelong Wu Junsheng Wang Zhongyao Li Yisheng Miao Chengpeng Xue Yuling Lang Decai Kong Xiaoying Ma Haibao Qiao School of Materials Science and Engineering Beijing Institute of TechnologyBeijing100081China Senior Engineer at the simulation center Citic Dicastal Co.Ltd.Qinhuangdao066010China

X-ray Computed Tomography(XCT)enables non-destructive acquisition of the internal structure of materials,and image segmentation plays a crucial role in analyzing material XCT *** paper proposes an image segmentation method based on the Segment Anything model(SAM).We constructed a dataset of carbide in nickel-based single crystal superalloys XCT images and preprocessed the images using median filtering,histogram equalization,and gamma ***,SAM was fine-tuned to adapt to the task of material XCT image segmentation,resulting in *** compared the performance of threshold segmentation,SAM,U-Net model,and *** method achieved 88.45%Class Pixel Accuracy(CPA)and 88.77%Dice Similarity Coefficient(DSC)on the test set,outperforming SAM by 5.25%and 8.81%,respectively,and achieving the highest ***-SAM demonstrated lower input requirements compared to SAM,as it only required three reference points for completing the segmentation task,which is one-fifth of the requirement of ***-SAM exhibited promising results,highlighting its potential as a novel method for material XCT image segmentation.

关键词： Segment Anything model X-ray computed tomography U-Net Ni-based superalloys foundation models

Characteristic Mode Analysis for Pattern Diversity and Beamforming: A Survey

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Chinese Journal of Electronics 2024年第5期33卷 1117-1126页

作者： Qianyun ZHANG Biyi WU School of Cyber Science and Technology Beihang University center for Electromagnetic simulation School of Integrated Circuits and Electronics Beijing Institute of Technology

With the rapid development of space-air-ground integrated communications, diverse requirements have been imposed on antenna radiation patterns. In addition, increasingly compact platforms brings significant challenges to the deployment of antenna arrays normally used for beamforming. This article comprehensively surveys characteristic mode analysis(CMA)-based pattern diversity realizations in past years. Specifically, exciting multiple characteristic modes independently achieves pattern reconfigurability and element-reduced multiple-input and multiple-output systems. We furthermore overview a series of works on modes superposition. Various methods have been explored for modal weights decision, and therefore specific patterns are synthesized. The weighted modal combination also fulfills single-element beamforming. A recent study on an antenna design for electrically small unmanned aerial vehicles(UAVs) is summarized, and the desired reconfigurable radiation patterns of the conformal radiator are realized based on CMA. Moreover, a formation-based beamforming technique, which takes advantages of the electromagnetic coupling among conformal radiators and the agility of UAVs, is introduced.

关键词： Characteristic mode analysis Beamforming Beamsteering Reconfigurable radiation pattern Characteristic mode analysis Beamforming Beamsteering Reconfigurable radiation pattern ANTENNA DESIGN MIMO FREQUENCY UWB

Highly active copper-intercalated weakly crystallized δ-MnO_(2) for low-temperature oxidation of CO in dry and humid air

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 127-136页

作者： Hao Zhang Huinan Li Pengyi Zhang Tingxia Hu Xianjie Wang State Key Joint Laboratory of Environment simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China beijing Key Laboratory for Indoor Air Quality Evaluation and Control Beijing100084China Midea Corporate Research center Foshan528311China

Copper intercalated birnessite MnO_(2)(δ-MnO_(2))with weak crystallinity and high specific surface area(421 m^(2)/g)was synthesized by a one-pot redox method and investigated for low-temperature CO *** molar ratio of Cu/Mn was as high as 0.37,which greatly weakened the Mn-O bond and created a lot of low-temperature active oxygen *** situ DRIFTS revealed strong bonding of copper ions with ***-synthesized MnO_(2)-150Cu achieved 100%conversion of 250 ppm CO in normal air(3.1 ppm H_(2)O)even at−10°C under the weight-hourly space velocity(WHSV)of 150 L/(g·h).In addition,it showed high oxygen storage capacity to oxidize CO in inert *** the concurrent moisture in air significantly inhibited CO adsorption and its conversion at ambient temperature,MnO_(2)-150Cu could stably convert CO in 1.3%moisture air at 70°C owing to its great low-temperature activity and reduced competitive adsorption of water with increased *** study discovers the excellent low-temperature activity of weakly crystallized δ-MnO_(2) induced by high content intercalated copper ions.

关键词： CO oxidation Birnessite Interlayer copper Low-temperature Oxygen storage capacity

Analysis on carbon emission reduction intensity of fuel cell vehicles from a life-cycle perspective

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Frontiers in Energy 2024年第1期18卷 16-27页

作者： Ziyuan TENG Chao TAN Peiyuan LIU Minfang HAN Fuel Cell and Energy Storage center Department of Energy and Power EngineeringState Key Laboratory of Control and Simulation of Power Systems and Generation EquipmentTsinghua UniversityBeijing 100084China

The hydrogen fuel cell vehicle is rapidly developing in China for carbon reduction and *** paper evaluated the life-cycle cost and carbon emission of hydrogen energy via lots of field surveys,including hydrogen production and packing in chlor-alkali plants,transport by tube trailers,storage and refueling in hydrogen refueling stations(HRSs),and application for use in two different *** also conducted a comparative study for battery electric vehicles(BEVs)and internal combustion engine vehicles(ICEVs).The result indicates that hydrogen fuel cell vehicle(FCV)has the best environmental performance but the highest energy ***,a sufficient hydrogen supply can significantly reduce the carbon intensity and FCV energy cost of the current *** carbon emission for FCV application has the potential to decrease by 73.1%in City A and 43.8%in City *** only takes 11.0%–20.1%of the BEV emission and 8.2%–9.8%of the ICEV *** cost of FCV driving can be reduced by 39.1%in City *** improvement can be obtained with an economical and“greener”hydrogen production pathway.

关键词： hydrogen energy life-cycle assessment(LCA) fuel cell vehicle carbon emission energy cost

Screening and identification of functional bacterial attachment genes in aerobic granular sludge

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Journal of Environmental Sciences 2024年第7期141卷 205-214页

作者： Kai Qiao Tingting Zhao LeiWang Wei Zhang WeiMeng Fan Liu Xu Gao Jianrong Zhu School of Environment Beijing Normal UniversityBeijing 100875China State Key Laboratory of Water simulation Beijing 100875China R&D Centre of Aerobic Granule Technology Beijing 100875China

The screening and identification of attachment genes is important to exploring the formation mechanism of biofilms at the gene *** is helpful to the development of key culture technologies for aerobic granular sludge(AGS).In this study,genome-wide sequencing and gene editing were employed for the first time to investigate the effects and functions of attachment genes in *** the help of whole-genome analysis,ten attachment genes were screened from thirteen genes,and the efficiency of gene screening was greatly ***,two attachment genes were selected as examples to further confirm the gene functions by constructing gene-knockout recombinant mutants of Stenotrophomonas maltophilia;when the two attachment genes were knocked out,the attachment potential was reduced by 50.67%and 43.93%,*** results provide a new theoretical principle and efficient method for the development of AGS from the perspective of attachment genes.

关键词： Attachment gene Genome-wide sequence Gene-knockout Attachment potential Aerobic granular sludge biofilm

Comparison of antimony and arsenic behaviour at the river-lake junction in the middle of the Yangtze River Basin

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Journal of Environmental Sciences 2024年第2期136卷 189-200页

作者： Huiji Liu Wei Zeng Ziyang Lai Mengchang He Chunye Lin Wei Ouyang Xitao Liu State Key Laboratory of Water Environment simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Advanced Interdisciplinary Institute of Environment and Ecology Beijing Normal UniversityZhuhai 519087China

As typical metalloid toxic elements widely distributed in environmental media,the geochemical behaviour of antimony(Sb)and arsenic(As)affects environmental *** selected the surface waters and sediments at the river-lake junction of Dongting Lake as the research objects,analysed the concentration and chemical partitioning of Sb and As,assessed its contamination and ecological risk levels,and discussed its sources and potential influencing *** concentrations of dissolved Sb and As in surface waters were low(<5.46μg/L),and the concentrations of Sb and As in surface sediments were 2.49-22.65mg/kg and 11.10-136.34 mg/kg,*** and As in sediments were mainly enriched in the fraction of residues,but the proportion of As in bioavailability was significantly higher than that of *** the contamination level of Sb was higher than that of As,the risk assessment code(RAC)showed that the ecological risk level of As was higher than that of *** erosion and mining activities(in the midstream of Zijiang River)were the main contaminated sources of Sb,while As was affect mainly by rainwater *** contamination and ecological risk of Sb in the inlet of the Zijiang River should receive considerable attention,while those of As in the inlet of the Xiangjiang River should also be seriously *** study highlights the need for multi-index-based assessments of contamination and ecological risk and the importance of further studies on the environmental behaviour of metalloids in specific hydrological conditions,such as river-lake junctions.

关键词： Contamination Ecological risks Antimony(Sb) Arsenic(As) River-lake junction Dongting Lake

Numerical and experimental research on axial injection end-burning hybrid rocket motors with polyethylene fuel

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Chinese Journal of Aeronautics 2024年第8期37卷 91-105页

作者： Xiangyu MENG Hui TIAN Lingfei HE Jingfei GAO Xiaoting NIU Guobiao CAI School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic simulation Technologies Ministry of EducationBeijing 100816China

This study investigates the end-burning hybrid rocket motors with polyethylene fuel by the numerical simulation and *** on computational fluid dynamics,a numerical model is *** model is validated by two firing tests in this hybrid rocket motor,which uses oxygen and polyethylene as *** results show that the numerical and experimental data are in good agreement,and the error of the chamber pressure is less than 2.63%.Based on the simulation mode,the blowoff limit of the end-burning hybrid rocket motors is *** the nozzle throat diameter and the inner diameter of grain are large,it is more difficult for the hybrid rocket motor to achieve end-burning mode,i.e.,the flame spreading is prevented in the narrow *** main reason is that when the nozzle throat and the grain port are large,chamber pressure and oxidizer flow velocity are ***,the friction velocity considering the pressure and flow velocity is *** critical friction velocity is about 4.054–4.890 m/s in the hybrid rocket *** the friction velocity exceeds the critical friction velocity,the combustion mode in hybrid rocket motors changes from the flame spreading mode to the end-burning ***,the regression rate formula is obtained by fitting,which shows that the regression rate has a good correlation with combustion chamber *** critical friction velocity and regression rate formula can provide an important reference for end-burning hybrid rocket motors.

关键词： Hybrid rocket motor End burning Blowoff limit Flame propagation Regression rate

A comprehensive fluid-solid coupling dynamic simulation for spatiotemporal distribution of regression rate in hybrid rocket motors

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Chinese Journal of Aeronautics 2024年第9期37卷 100-112页

作者： Tianfang WEI Guobiao CAI Hui TIAN Xiangyu MENG Xianzhu JIANG Xiaoming GU School of Astronautics Beihang UniversityBeijing 100191China Key Laboratory of Spacecraft Design Optimization&Dynamic simulation Technologies Ministry of Education Beijing 100191China

The spatiotemporal distribution characteristics of the regression rate are crucial aspects of the research on Hybrid Rocket Motor(HRM).This study presents a pioneering effort in achiev-ing a comprehensive numerical simulation of fluid dynamics and heat transfer in both the fluid and solid regions throughout the entire operation of an *** accomplish this,a dynamic grid tech-nique that incorporates fluid-solid coupling is *** validate the precision of the numerical simulations,a firing test is conducted,with embedded thermocouple probes being used to measure the inner temperature of the fuel *** temperature variations in the solid fuel obtained from both experiment and simulations show good *** maximum combustion temperature and average thrust obtained from the simulations are found to deviate from the experimental results by only 3.3%and 2.4%,***,it can be demonstrated that transient numerical simu-lations accurately capture the fluid-solid coupling characteristics and transient regression *** dynamic simulation results of inner flow field and solid region throughout the entire working stage reveal that the presence of vortices enhances the blending of combustion gases and improves the regression rate at both the front and rear ends of the fuel *** addition,oscillations of the regression rate obtained in the simulation can also be well corresponded with the corrugated surface observed in the ***,the zero-dimension regression rate formula and the for-mula describing the axial location dependence of the regression rate are fitted from the simulation results,with the corresponding coefficients of determination(R°)of 0.9765 and 0.9298,*** research serves as a reference for predicting the performance of HRM with gas oxygen and polyethylene,and presents a credible way for investigating the spatiotemporal distribution of the regression rate.

关键词： Hybrid Rocket Motor(HRM) Transient numerical simulation Fluid-solid couplingheat transfer Spatiotemporal distribution of regression rate Dynamic grid