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Uncertain multicast under dynamic behaviors

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Frontiers of Computer Science 2020年第1期14卷 130-145页

作者： Yudong QIN Deke GUO Zhiyao HU bangbang ren Science and Technology on Information System Engineering Laboratory National University of Defense TechnologyChangsha 410073China

Multicast transfer can efficiently save the bandwidth consumption and reduce the load on the source node than a series of independent unicast ***,many applications employ the content replica strategy to improve the robustness and efficiency;hence each file and its replicas are usually distributed among multiple *** such scenarios,the traditional deterministic multicast develops into the Uncertain multicast,which has more flexibility in the source *** this paper,we focus on building and maintaining a minimal cost forest(MCF)for any uncertain multicast,whose group members(source nodes and destination nodes)may join or leave after constructing a *** formulate this dynamic minimal cost forest(DMCF)problem as a mixed integer programming *** then design three dedicated methods to approximate the optimal *** them,our a-MCF aims to efficiently construct an MCF for any given uncertain multicast,without dynamic behaviors of multicast group *** d-MCF method motivates to slightly update the existing MCF via local modifications once appearing a dynamic *** can achieve the balance between the minimal cost and the minimal modifications to the existing *** last r-MCF is a supplement method to the d-MCF method,since many rounds of local modifications maymake the resultant forest far away from the optimal ***,our r-MCF method monitors the accumulated degradation and triggers the rearrangement process to reconstruct an new MCF when *** comprehensive evaluation results demonstrate that our methods can well tackle the proposed DMCF problem.

关键词： uncertain multicast dynamic behaviors routing forest approximation algorithm Steiner tree

TIO: A VLC-Enabled Hybrid Data Center Network Architecture

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Tsinghua Science and Technology 2019年第4期24卷 484-496页

作者： Yudong Qin Deke Guo Guoming Tang bangbang ren the Science and Technology on Information System Engineering Laboratory National University of Defense Technology

To satisfy the ever-increasing bandwidth demand of modern data centers, researchers have proposed hybrid Data Center Networks(DCNs), which employ high-bandwidth Optical Circuit Switches(OCSs) to compensate for Electrical Packet Switches(EPS). Existing designs, such as Helios and c-Through, mainly focus on reconfiguring optical devices to meet the estimated traffic requirements. However, these designs face two major challenges in their OCS-based networks, namely, the complex control mechanism and cabling problems. To solve these challenges, we propose TIO, a hybrid DCN that employs Visible Light Communication(VLC) instead of wired OCS design to connect racks. TIO integrates the wireless VLC-based Jellyfish and wired EPS-based Fat Tree seamlessly and combines the opposite and complementary characteristics, including wireless VLC direct connection and wired electrical packet switching, random graph, and Clos topology properties. To further exploit the merits of TIO, we design a hybrid routing scheme and congestion-aware flow scheduling method. Comprehensive evaluations indicate that TIO outperforms the Jellyfish and Fat Tree in both topology properties and network performance, and the flow scheduling method also evidently improves performance.

关键词： Data Center Network(DCN) visible light communication wireless links topology design

Comparing Set Reconciliation Methods Based on Bloom Filters and Their Variants

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Tsinghua Science and Technology 2016年第2期21卷 157-167页

作者： Zhiyao Hu Xiaoqiang Teng Deke Guo bangbang ren Pin Lv Zhong Liu College of Information System and Management National University of Defense TechnologyChangsha 410073China School of Computer Electronics and InformationGuangxi UniversityNanning 530004China.

Set reconciliation between two nodes is widely used in network applications. The basic idea is that each member of a node pair has an object set and seeks to deliver its unique objects to the other member. The Standard Bloom Filter （SBF） and its variants, such as the Invertible Bloom Filter （IBF）, are effective approaches to solving the set reconciliation problem. The SBF-based method requires each node to represent its objects using an SBF, which is exchanged with the other node. A receiving node queries the received SBF against its local objects to identify the unique objects. Finally, each node exchanges its unique objects with the other node in the node pair. For the IBF- based method, each node represents its objects using an IBF, which is then exchanged. A receiving node subtracts the received IBF from its local IBF so as to decode the different objects between the two sets. Intuitively, it would seem that the IBF-based method, with only one round of communication, entails less communication overhead than the SBF-based method, which incurs two rounds of communication. Our research results, however, indicate that neither of these two methods has an absolute advantages over the others. In this paper, we aim to provide an in-depth understanding of the two methods, by evaluating and comparing their communication overhead. We find that the best method depends on parameter settings. We demonstrate that the SBF-based method outperforms the IBF-based method in most cases. But when the number of different objects in the two sets is below a certain threshold, the IBF-based method outperforms the SBF-based method.

关键词： set reconciliation bloom filter communication overheads

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数据中心内Incast流量的网内聚合研究

计算机研究与发展 2016年第1期53卷 53-67页

作者：郭得科罗来龙李妍胡智尧任棒棒信息系统工程国防科技重点实验室(国防科学技术大学) 长沙410073

MapReduce等分布式计算系统应用在数据中心内产生了严重的东西向流量,其中以incast和shuffle为代表的关联性流量占相当大的比重,进而严重影响到上层应用的性能.这促使研究者们考虑在这些关联性流量的网内传输阶段尽可能早而不是仅在流... 详细信息

MapReduce等分布式计算系统应用在数据中心内产生了严重的东西向流量,其中以incast和shuffle为代表的关联性流量占相当大的比重,进而严重影响到上层应用的性能.这促使研究者们考虑在这些关联性流量的网内传输阶段尽可能早而不是仅在流量的接收端进行流间数据聚合.首先以新型数据中心网络结构为背景讨论流间数据聚合的可行性和增益,为最大化该增益,为incast传输建立最小代价树模型.为解决该模型,提出了2种近似的incast树构造方法,其能够仅基于incast成员的位置和数据中心拓扑结构生成一个有效的incast树,进一步解决了incast树的动态和容错问题.最后,采用原型系统和大规模仿真的方法评估了incast流量的网内聚合方法,实验结果证明该方法能大幅降低incast流量造成的传输开销,能节约数据中心的网络资源.同时,提出的模型和解决方法也适用于其他类型的数据中心网络结构.

关键词：网内聚合数据中心 incast传输 shuffle传输网络流量

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云数据中心网络控制器的均衡选择策略

指挥信息系统与技术 2019年第4期10卷 96-100页

作者：牟建红任棒棒解放军31101部队南京210000 国防科技大学信息系统工程重点实验室长沙410073

为了在韧性信息服务云环境中多个控制器间均衡数据流,以便更好地承载业务数据流,提出了基于控制器负载和基于时延的控制器选择策略。在该策略下,每个交换机从所有可用的控制器中选择一个最优控制器,从而有效减少数据流的最大响应时间。... 详细信息

为了在韧性信息服务云环境中多个控制器间均衡数据流,以便更好地承载业务数据流,提出了基于控制器负载和基于时延的控制器选择策略。在该策略下,每个交换机从所有可用的控制器中选择一个最优控制器,从而有效减少数据流的最大响应时间。试验结果表明,设计的2个自适应控制器选择策略能够有效减少数据流的最大响应时间,进而提高系统吞吐量。

关键词：控制器选择队列管理软件定义网络

Molecular dynamics simulations of helium transport through inorganic mineral nanopores

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Science China Earth Sciences 2025年第1期68卷 237-252页

作者： Dandan SONG Ping GUAN Chi ZHANG Jiahao ren School of Earth and Space Sciences Peking University

Helium transport through nanoscale inorganic mineral pores and pore throats is essential for its overall migration. To elucidate helium's transport dynamics within nanopores, we employed equilibrium and non-equilibrium molecular dynamics simulations to investigate helium's static self-diffusion and pressure-driven flow in quartz slit-shaped nanopores. We also introduced water and various gases, including hydrogen, methane, ethane, nitrogen, and carbon dioxide, into the nanopores to assess their influence on helium transport. Our findings indicate minimal helium adsorption on quartz pore surfaces. Under conditions where the pore size is less than 5 nm and the pressure under 10 MPa, environmental factors markedly influence helium diffusion. Large pore sizes, high temperatures, and low gas pressures enhance helium desorption and facilitate faster diffusion. We observed a positive correlation between helium flow velocity and factors such as pore size, pressure gradient, and surface smoothness of the pores. Notably, the presence of pore water and carrier gases in quartz nanopores, which diffuse more slowly than helium, tends to reduce helium surface adsorption and slow its diffusion. Among the carrier gases studied, nitrogen showed similar adsorption capacity, diffusivity, and stability to helium, while carbon dioxide displayed the highest adsorption capacity and the slowest diffusion rate, markedly differing from helium. Based on the simulation results, we concluded that water and carrier gases primarily function as transport mediums in helium migration, moving together with helium. Nitrogen, which shares similar properties with helium, effectively assists in this co-migration process. Conversely, carbon dioxide, due to its high adsorption capacity and slow diffusion, tends to be lost during co-migration. As a result, gas reservoirs with high nitrogen levels and low carbon dioxide levels are more likely to have higher helium concentrations. Additionally, the smaller por

关键词： Helium transport Slit nanopores Molecular dynamics simulations Diffusion Flow carriers

基于多智能体深度强化学习的体系任务分配方法

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指挥与控制学报 2023年第1期9卷 93-102页

作者：林萌龙陈涛任棒棒张萌萌陈洪辉国防科技大学信息系统工程重点实验室湖南长沙410073

为了应对在未来复杂的战场环境下,由于通信受限等原因导致的集中式决策模式难以实施的情况,提出了一个基于多智能体深度强化学习的分布式作战体系任务分配算法,该算法为各作战单元均设计一个独立的策略网络,并采用集中式训练、分布式执... 详细信息

为了应对在未来复杂的战场环境下,由于通信受限等原因导致的集中式决策模式难以实施的情况,提出了一个基于多智能体深度强化学习的分布式作战体系任务分配算法,该算法为各作战单元均设计一个独立的策略网络,并采用集中式训练、分布式执行的方法对智能体的策略网络进行训练,结果显示,经过学习训练后的各作战单元具备一定的自主协同能力,即使在没有中心指挥控制节点协调的情况下,依然能够独立地实现作战任务的高效分配.

关键词：多智能体系统深度强化学习体系架构体系设计

Tailoring Light–Matter Interactions in Overcoupled Resonator for Biomolecule Recognition and Detection

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Nano-Micro Letters 2025年第1期17卷 262-280页

作者： Dongxiao Li Hong Zhou Zhihao ren Cheng Xu Chengkuo Lee Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore Center for Intelligent Sensors and MEMS(CISM) National University of SingaporeSingapore 117608Singapore

Plasmonic nanoantennas provide unique opportunities for precise control of light–matter coupling in surface-enhanced infrared absorption(SEIRA)spectroscopy,but most of the resonant systems realized so far suffer from the obstacles of low sensitivity,narrow bandwidth,and asymmetric Fano resonance ***,we demonstrated an overcoupled resonator with a high plasmon-molecule coupling coefficient(μ)(OC-Hμresonator)by precisely controlling the radiation loss channel,the resonator-oscillator coupling channel,and the frequency detuning *** observed a strong dependence of the sensing performance on the coupling state,and demonstrated that OC-Hμresonator has excellent sensing properties of ultra-sensitive(7.25%nm^(−1)),ultra-broadband(3–10μm),and immune asymmetric Fano *** characteristics represent a breakthrough in SEIRA technology and lay the foundation for specific recognition of biomolecules,trace detection,and protein secondary structure analysis using a single array(array size is 100×100μm^(2)).In addition,with the assistance of machine learning,mixture classification,concentration prediction and spectral reconstruction were achieved with the highest accuracy of 100%.Finally,we demonstrated the potential of OC-Hμresonator for SARS-CoV-2 *** findings will promote the wider application of SEIRA technology,while providing new ideas for other enhanced spectroscopy technologies,quantum photonics and studying light–matter interactions.

关键词： Plasmonic nanoantennas Light-matter interaction Surface-enhanced infrared absorption Overcoupled Biosensing

A Review on Thermal Management of Li-ion Battery:from Small-Scale Battery Module to Large-Scale Electrochemical Energy Storage Power Station

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Journal of Thermal Science 2025年第1期34卷 1-23页

作者： CHEN Zhifeng JIA Li YIN Liaofei DANG Chao ren Honglei ZHANG Zhiqiang Beijing Key Laboratory of Flow and Heat Transfer of Phase Changing in Micro and Small Scale School of MechanicalElectronic and Control EngineeringBeijing Jiaotong University

Li-ion battery is an essential component and energy storage unit for the evolution of electric vehicles and energy storage technology in the ***,in order to cope with the temperature sensitivity of Li-ion battery and maintain Li-ion battery safe operation,it is of great necessary to adopt an appropriate battery thermal management system(BTMS).In this paper,the current main BTM strategies and research hotspots were discussed from two aspects:small-scale battery module and large-scale electrochemical energy storage power station(EESPS).The practical application situation,advantages and disadvantages,and the future development trend of each heat dissipation method(air,liquid,PCM,heat pipe,hybrid cooling) were described in *** them,the air cooling and liquid cooling were reviewed in-depth based on the engineering *** PCM,heat pipe and hybrid cooling were reviewed extensively based on the latest *** research provides a comprehensive understanding for the BTMS in all scales.

关键词： battery thermal management cooling methods large-scale electrochemical energy storage power station small-scale battery module