检索结果-内蒙古大学图书馆

Traveling wave solutions for a three-component noncooperative systems arising in nonlocal diffusive biological models

引用

International Journal of Biomathematics 2024年第7期17卷 187-216页

作者： Ran Zhang Hongyong Zhao School of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing 211106 P.R.China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA)MIIT Nanjing 211106P.R.China School of Mathematical Science Heilongjiang University Harbin 150080P.R.China

This paper aims to study the existence of traveling wave solutions(TWS)for a three-component noncooperative systems with nonlocal *** main results reveal that when a threshold R>1,there exists a critical wave speed c^(*)>*** using sub-and super-solution methods and Schauder's fixed point theorem,we prove that the system admits a nontrivial TWS for each c≥c^(*).Meanwhile,we show that there exists no nontrivial TWS for c

关键词： Traveling wave solution nonlocal diffusion biological model Schauder's fixed point theorem noncooperative systems

来源：评论

学校读者我要写书评

暂无评论

LOW-FREQUENCY BANDGAP BROADENING OF INERTIAL AMPLIFICATION METAMATERIALS 29

LOW-FREQUENCY BANDGAP BROADENING OF INERTIAL AMPLIFICATION M...

引用

29th International Congress on Sound and Vibration, ICSV 2023

作者： Sun, Yonghang Xi, Chenyang Zheng, Hui State Key Laboratory of Mechanical System and Vibration School of Mechanical Engineering Shanghai Jiao Tong University Shanghai200240 China Institute of High Performance Computing A*STAR 138632 Singapore

ISBN: (纸本)9788011034238

The recent development of inertial amplification (IA) metamaterial provides a new venue for insulating low-frequency vibration and noise. It is different from conventional manners that over-rely on the structural density and therefore lead to prohibitively heavy structures. In this work, bandgap broadening techniques of a lever-type IA (LIA) metamaterial are explored on the premise of the same additional mass. Three methods are proposed here, respectively based on bandgap coupling mechanism, multi-resonance mechanism and parametric detuning mechanism. Their broadening performances are investigated via band-structures of unit cells and vibration transmissibility of finite structures. Numerical results show that an ultra-wide bandgap can be obtained by combining the bandgap coupling effect with installation position of LIA mechanism and structural damping of the host plate. Moreover, the introduction of multi-resonance mechanism can widen the low-frequency IA bandgap on the one hand, and more new bandgaps are generated due to multiple combinations of vibration of LIA mechanisms on the other hand. Parametric detuning of LIA mechanisms moves the cut-on and cut-off edges of IA bandgap to lower and higher frequency, respectively. The passband between IA and Bragg bandgaps changes to a stopband when the periodicity of finite structures is broken, and an ultra-wide stopband is obtained which from the cut-on frequency of IA bandgap to the cut-off frequency of Bragg bandgap. © 2023 Proceedings of the International Congress on Sound and Vibration. All rights reserved.

关键词： Energy gap

来源：评论

学校读者我要写书评

暂无评论

Arbitrarily high-Order Energy-Preserving Schemes for the Camassa-Holm Equation Based on the Quadratic Auxiliary Variable Approach

引用

Advances in Applied Mathematics and Mechanics 2023年第5期15卷 1233-1255页

作者： Yuezheng Gong Qi Hong Chunwu Wang Yushun Wang School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjingJiangsu 211106China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjingJiangsu 211106China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical SciencesNanjing Normal UniversityNanjingJiangsu 210023China

In this paper,we present a quadratic auxiliary variable(QAV)technique to develop a novel class of arbitrarily high-order energy-preserving algorithms for the Camassa-Holm *** QAV approach is first utilized to transform the original equation into a reformulated QAV system with a consistent initial *** the reformulated QAV system is discretized by applying the Fourier pseudo-spectral method in space and the symplectic Runge-Kutta methods in time,which arrives at a class of fully discrete *** the consistent initial condition,they can be rewritten as a new fully discrete system by eliminating the introduced auxiliary variable,which is rigorously proved to be energy-preserving and *** numerical experiments are conducted to confirm the expected order of accuracy,conservative property and efficiency of the proposed *** presented numerical strategy makes it possible to directly apply a special class of Runge-Kutta methods to develop energy-preserving algorithms for a general conservative system with any polynomial energy.

关键词： Camassa-Holm equation quadratic auxiliary variable high-order energy-preserving schemes symplectic Runge-Kutta methods

来源：评论

学校读者我要写书评

暂无评论

ASBase:The universal database for aggregate science

Aggregate

引用

Aggregate 2023年第1期4卷 148-157页

作者： Junyi Gong Wanjun Gong BoWu Haoran Wang Wei He Zhongyang Dai Yangzhong Li Yong Liu Zhiming Wang Xiaojun Tuo Jacky W.Y.Lam Zijie Qiu Zheng Zhao Ben Zhong Tang Shenzhen Institute of Aggregate Science and Technology School of Science and EngineeringThe Chinese University of Hong KongShenzhenGuangdongChina AIE-Institute State Key Laboratory of Luminescence Materials and DevicesCenter of Aggregation-induced EmissionKey Laboratory of Luminescence from Molecular Aggregates of Guangdong ProvinceSouth China University of Technology(SCUT)GuangzhouChina High Performance Computing Department National Supercomputing Center in ShenzhenShenzhenChina Department of Chemistry Hong Kong University of Science and TechnologyKowloonHong KongChina

This paper reports the first universal and versatile database on aggregate materials for the field of aggregate science *** the current stage,the database(http://119.91.135.188:8080/)contains over 1000 entries of organic aggregate material systems(mainly luminescent systems at the current stage)with a unique data structure which is designed particularly for aggregate materials and containing the photophysics and physicochemical properties of the compounds in different statuses of aggregation,including dilute solution form,pristine solid-state,stable crystalline,and nanoaggregates formed in *** web-based interface of the database provided functions to index,search,manipulate,fetch and deposit data *** addition,a background calculation service optimizes the chemical structure of new entries on different levels of *** database also provided background API for interactive developments of prediction or regression models based on machine-learning algorithms.

关键词： aggregate science aggregation-induced emission data-driven model database

来源：评论

学校读者我要写书评

暂无评论

Thermally Evaporated ZnSe for Efficient and Stable Regular/Inverted Perovskite Solar Cells by Enhanced Electron Extraction

引用

Energy & Environmental Materials 2023年第5期6卷 440-448页

作者： Xin Li Guibin Shen Xin Ren Ng Zhiyong Liu Yun Meng Yongwei Zhang Cheng Mu Zhi Gen Yu Fen Lin Solar Energy Research Institute of Singapore(SERIS) National University of SingaporeSingapore 117574Singapore Key Laboratory of Advanced Light Conversion Materials and Biophotonics Department of ChemistryRenmin University of ChinaBeijing 100872China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Shandong Provincial Engineering and Technical Center of Light Manipulation and Shandong Provincial Key Laboratory of Optics and Photonic Devices School of Physics and ElectronicsShandong Normal UniversityJinan 250014China Institute of High Performance Computing A^(*)STARSingapore 138632Singapore

Electron transport layers(ETLs)are crucial for achieving efficient and stable planar perovskite solar cells(PSCs).Reports on versatile inorganic ETLs using a simple film fabrication method and applicability for both low-cost planar regular and inverted PSCs with excellent efficiencies(>22%)and high stability are very ***,we employ a novel inorganic ZnSe as ETL for both regular and inverted PSCs to improve the efficiency and stability using a simple thermal evaporation *** TiO_(2)-ZnSe-FAPbl_(3)heterojunction could be formed,resulting in an improved charge collection and a decreased carrier recombination further proved through theoretical *** optimized regular PSCs based on TiO_(2)/ZnSe have achieved 23.25%efficiency with negligible *** addition,the ZnSe ETL can also effectively replace the unstable bathocuproine(BCP)in inverted ***,the ZnSe-based inverted device realizes a champion efficiency of 22.54%.Moreover,the regular device comprising the TiO_(2)/ZnSe layers retains 92%of its initial PCE after 10:00 h under 1 Sun continuous illumination and the inverted device comprising the C_(60)/ZnSe layers maintains over 85%of its initial PCE at 85℃for 10:00 *** highlights one of the best results among universal ETLs in both regular and inverted perovskite photovoltaics.

关键词： high efficiency long-term stability planar regular/inverted perovskite solar cells thermal evaporation ZnSe electron transport layer

来源：评论

学校读者我要写书评

暂无评论

Octree K-nearest neighbor parallel query 4

Octree K-nearest neighbor parallel query

引用

4th International Conference on Computer Vision and Pattern Analysis, ICCPA 2024

作者： Nong, Jian Xu, Jian He, Xi Li, Wenge Huang, Hongben Guangxi Key Laboratory of Machine Vision and Intelligent Control Wuzhou University Wuzhou543002 China High Performance Computing Laboratory Wuzhou University Wuzhou543002 China CCTEG Taiyuan Research Institute Co. Ltd. Taiyuan030006 China

ISBN: (纸本)9781510682528

Nearest neighbor queries have widespread applications in fields such as computer vision, data mining, pattern recognition, document retrieval, and geographic information systems. The traditional k-nearest neighbor algorithm based on branch-and-bound and octree requires the use of a priority queue to maintain the result set. However, in large-scale data scenarios, the efficiency of the priority queue decreases, leading to a decline in query efficiency. Additionally, implementing parallelism using tree-based storage structures, such as octree, can be challenging. This paper proposes a parallel k-nearest neighbor query algorithm for multi-core CPU environments based on octree. This method adopts a divide-and-conquer approach by dividing the dataset into multiple parts and constructing octree for each part. Then, it utilizes parallel max-heaps to calculate the distances of pruned data and selects the nearest K elements to achieve K-nearest neighbor query. This method utilizes multiprocessors for tree construction and result set maintenance, further accelerating the query speed. Experimental results show that in large-scale data scenarios, this method achieves significant acceleration compared to sequential query. © 2024 SPIE.

关键词： Nearest neighbor search

来源：评论

学校读者我要写书评

暂无评论

DiffForward: On Balancing Forwarding Traffic for Modern Cloud Block Services via Differentiated Forwarding 23

DiffForward: On Balancing Forwarding Traffic for Modern Clou...

引用

2023 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems, SIGMETRICS 2023

作者： Zhu, Wenzhe Li, Yongkun Xu, Erci Li, Fei Xu, Yinlong Lui, John C. S. University of Science and Technology of China Hefei China PDL Changsha China Alibaba Group Beijing China Anhui Province Key Laboratory of High Performance Computing USTC Hefei China The Chinese University of Hong Kong Hong Kong

ISBN: (纸本)9798400700743

Modern cloud block service provides cloud users with virtual block disks (VDisks), and it usually relies on a forwarding layer consisting of multiple proxy servers to forward the block-level writes from applications to the underlying distributed storage. However, we discover that severe traffic imbalance exists among the proxy servers at the forwarding layer, thus creating a performance bottleneck which severely prolongs the latency of accessing VDisks. Worse yet, due to the diverse access patterns of VDisks, stable traffic and burst traffic coexist at the forwarding layer, and thus making existing load balancing designs inefficient for balancing the traffic at the forwarding layer of VDisks, as they are unaware of and also lack the ability to differentiate the decomposable burst and stable traffic. To this end, we propose a novel traffic forwarding scheme DiffForward for cloud block services. DiffForward differentiates the burst traffic from stable traffic in an accurate and efficient way at the client side, then it forwards the burst traffic to a decentralized distributed log store to realize real-Time load balance by writing the data in a round-robin manner and balances the stable traffic by segmentation. DiffForward also judiciously coordinates the stable and burst traffic and preserves strong consistency under differentiated forwarding. Extensive experiments with reallife workloads on our prototype show that DiffForward effectively balances the traffic at the forwarding layer at a fine-grained subsecond level, thus significantly reducing the write latency of VDisks. © 2023 Owner/Author.

关键词： Digital storage

来源：评论

学校读者我要写书评

暂无评论

MPress: Democratizing Billion-Scale Model Training on Multi-GPU Servers via Memory-Saving Inter-Operator Parallelism

MPress: Democratizing Billion-Scale Model Training on Multi-...

引用

IEEE Symposium on high-performance Computer Architecture

作者： Quan Zhou Haiquan Wang Xiaoyan Yu Cheng Li Youhui Bai Feng Yan Yinlong Xu University of Science and Technology of China Anhui Province Key Laboratory of High Performance Computing University of Houston

It remains challenging to train billion-scale DNN models on a single modern multi-GPU server due to the GPU memory wall. Unfortunately, existing memory-saving techniques such as GPU-CPU swap, recomputation, and ZeRO-Series come at the price of extra computation, communication overhead, or limited memory *** present MPress, a new single-server multi-GPU system that breaks the GPU memory wall of billion-scale model training while minimizing extra cost. MPress first discusses the trade-offs of various memory-saving techniques and offers a holistic solution, which alternatively chooses the inter-operator parallelism with low cross-GPU communication traffics, and combines with recomputation and swap, to balance training performance and sustained model sizes. Additionally, MPress employs a novel, fast D2D swap technique, which simultaneously utilizes multiple high-bandwidth NVLink to swap tensors to light-load GPUs, based on a key observation that inter-operator parallel training may result in imbalanced GPU memory utilization and spare memory space from least used devices plus the high-end interconnects among them have the opportunity to support low-overhead swapping. Finally, we integrate MPress with PipeDream and DAPPLE, two representative inter-operator parallel training systems. Experimental results with two popular DNN models, Bert, and GPT, on two modern GPU servers from the DGX-1 and DGX-2 generation, equipped with 8 V100 or A100 cards, respectively, demonstrate that MPress significantly improves the training throughput over ZeRO-Series with the identical memory reduction, while being able to train larger models than the recomputation baseline.

关键词： Training performance evaluation Tensors Costs Computational modeling Graphics processing units Parallel processing

来源：评论

学校读者我要写书评

暂无评论

TAG: An Efficient Storage System Towards Transactional and Analytical Processing on Property Graphs

TAG: An Efficient Storage System Towards Transactional and A...

引用

International Workshop on Quality of Service

作者： Mingxiang Lu Min Lyu Yinlong Xu AnHui Province Key Laboratory of High Performance Computing University of Science and Technology of China Hefei China

The property graph, as the most widely adopted graph data model, is utilized extensively in various graph systems. However, these systems encounter challenges with regards to high latency, particularly when it comes to graph analysis workloads. Conversely, graph analysis systems are geared towards simple graphs and have limited transactional workload support. There is a growing demand for a graph storage system that can efficiently handle both workloads on the property graph. In this paper, we propose TAG, a graph storage system that surpasses the performance of transactional graph systems and achieves comparable results to that of graph analysis systems. We introduce a novel hybrid architecture for graph storage, incorporating in-memory indexes to enhance graph topology queries and label-based pages to optimize access to the properties. Through experimental evaluations, we demonstrate the superiority of TAG over state-of-the-art graph databases.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Self-supervised Domain Adaptation for Satellite Imagery Classification via Representation Learning 2

Self-supervised Domain Adaptation for Satellite Imagery Clas...

引用

2nd IEEE International Conference on Big Data, Artificial Intelligence and Internet of Things Engineering, ICBAIE 2021

作者： Wen, Hao Hu, Xiang Peng, Yuanxi National University of Defense Technology State Key Laboratory of High-Performance Computing Changsha China

ISBN: (纸本)9780738131221

Hyperspectral image (HSI) classification has been attracting widespread attention in the field of computer vision and achieved remarkable results due to the rapid development of deep learning. All existing HSI classification models are based on a closed set assumption where both the training and testing data are drawn from a known common domain. However, since the satellite imagery covers an extremely vast area, it is almost impossible to guarantee the representativeness of the training samples. To tackle the aforementioned problem, we propose a self-supervised domain adaptation model that recognizes the instances coming from unknown classes while maintaining accuracy on known classes. First, we employ a novel neighborhood representation learning to learn a discriminative representation in an unsupervised way. Second, we utilize an entropy separation loss to either match each target instance with a source prototype, or reject it as 'unknown'. Experiments on multiple HSI benchmarks demonstrate the effectiveness and superiority of the proposed method. © 2021 IEEE.

关键词： Remote sensing

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：