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RSAD： A Robust Distributed Contention-Based Adaptive Mechanism for IEEE 802.11 Wireless LANs

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Journal of Computer Science & Technology 2005年第2期20卷 282-288页

作者： yongpeng shi-duancheng Jun-LiangChen NationalLaboratoryofSwitchingTechnologyandTelecommunicationNetworksBeijingUniversityofPostsandTelecommunications Beijing100876P.R.China

Previous researches have shown that Distributed Coordination Function (DCF) access mode of IEEE 802.11 has lower performance in heavy contention environment. Based on the in-depth analysis of IEEE 802.11 DCF, NSAD (New Self-adapt DCF-based protocol) has been proposed to improve system saturation-throughput in heavy contention condition. The initial contention window tuning algorithm of NSAD is proved effective in error-free environment. However, problems concerning the exchanging of initial contention window occur in error-prone environment. Based on the analysis of NSAD's performance in error-prone environment, RSAD is proposed to further enhance the performance. Simulation in a more real shadowing error-prone environment is done to compare the performance of NSAD and RSAD and results have shown that RSAD can achieve further performance improvement as expected in the-error-prone environment than NSAD (i.e., better goodput and fairness index).

关键词： distributed coordination function (DCF) wireless LAN (WLAN) performance enhancement robust

Multi-Sensor Fusion Adaptive Estimation for Nonlinear Under-observed System with Multiplicative Noise

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Chinese Journal of Electronics 2024年第1期33卷 282-292页

作者： yongpeng CUI Xiaojun SUN School of Electronic Engineering Heilongjiang University Key Laboratory of Information Fusion Estimation and Detection

The adaptive fusion estimation problem was studied for the multi-sensor nonlinear under-observed systems with multiplicative noise. A one-step predictor with state update equations was designed for the virtual state with virtual noise first of all. An extended incremental Kalman filter(EIKF) was then proposed for the nonlinear under-observed systems. Furthermore, an adaptive filtering method was given for optimization. The fusion adaptive incremental Kalman filter weighted by scalar was finally proposed. The comparison analysis was made to verify the optimization of the state estimation using adaptive filtering method in the filtering process.

关键词： Adaptive systems Information filters Matrices Adaptive estimation Kalman filters State estimation Nonlinear systems

A VNS-NPGA Approach to Multi-Objective Optimization of Hub-and-spoke Logistics Network

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Journal of Traffic and Transportation Engineering(English Edition) 2024年

作者： Changxi Ma Chuwei shi Yun Yang yongpeng Zhao Zhuye Xu Bo Du School of Traffic and Transportation Lanzhou Jiaotong University Key Laboratory of Railway lndustry on Plateau Railway Transportation Intelligent Management and Control Lanzhou Jiaotong University School of Tourism and Management Yangling Vocational and Technical College School of New Energy and Power Engineering Lanzhou Jiaotong University National Engineering Research Center of Highway Maintenance Technology Changsha University of Science & Technology SMART Infrastructure Facility University of Wollongong

To realize low-cost freight transport in the logistics network and improve the network operation efficiency， a multi-objective optimization model and the corresponding algorithm for a hub-and-spoke logistics network are proposed based on the multi-level location of hub points and channels layout. By considering the structure of the multi-level hub-and-spoke logistics network and the features of the connectivity between the hub and spoke points， the multi-objective optimization model is constructed with two objectives of minimizing the total network operation costs and the total network service time. By considering the characteristics of decision variables and models， a Variable Neighborhood Search (VNS)-Niched Pareto Genetic Algorithm (NPGA) approach with a three-stage encoding structure chromosome is proposed， where the VNS algorithm nested in NPGA is used for individual variable neighborhood search to optimize individual channel level genes， and NPGA is adopted to solve the multi-objective optimization model. To evaluate the performance of the proposed VNS-NPGA approach， a real-life case study based on a small-scale Australia Post data set was conducted， and 25 nodes of the Australia Post and 14 nodes of the Gansu Province 3-level hub-and-spoke logistics networks were established， respectively. The analysis results indicated that the network structure of multi-level hub points could avoid the detour problem existing in the traditional hub-and-spoke network， and showed better applicability in the narrow geographical structure. Compared to the traditional multi-objective evolutionary algorithms， VNS-NPGA can obtain better solutions through the distributed optimization of channel levels， avoiding the problem that a single algorithm cannot effectively deal with coupling relationships in genes.

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Influence of Surface Ice Roughness on the Aerodynamic Performance of Wind Turbines

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2029-2043页

作者： Xin Guan Mingyang Li shiwei Wu Yuqi Xie yongpeng Sun School of New Energy Shenyang Engineering CollegeShenyang110136China Shenyang Key Laboratory Clean Energy Fine Comprehensive Utilization and Scheduling Energy Storage Shenyang110136China

The focus of this research was on the equivalent particle roughness height correction required to account for the presence of ice when determining the performances of wind *** particular,two icing processes(frost ice and clear ice)were examined by combining the FENSAP-ICE and FLUENT analysis *** ice type on the blade surfaces was predicted by using a multi-time step ***,the influence of variations in icing shape and ice surface roughness on the aerodynamic performance of blades during frost ice formation or clear ice formation was *** results indicate that differences in blade surface roughness and heat flux lead to disparities in both ice formation rate and shape between frost ice and clear *** ice has a greater impact on aerodynamics compared to frost ice,while frost ice is significantly influenced by the roughness of its icy surface.

关键词： Wind turbine icing blade surface roughness aerodynamic characteristics airfoil

6G New Multiple Access Technology

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China Communications 2024年第1期21卷 I0002-I0005页

作者： Yifei Yuan yongpeng Wu Lei Wang Zhifeng Yuan Wei Bai Yuanwei Liu Tsinghua University in China Carnegie Mellon University USA Wuhan University WuhanChina Southeast University NanjingChina Carleton University OttawaONCanada Nanjing University of Post and Telecommunications Shanghai Jiaotong University ShanghaiChina the School of Electronic Engineering and Computer Science Queen Mary University of London

As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the *** the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology.

关键词： technology Access attracting

RAD-seq data reveals robust phylogeny and morphological evolutionary history of Rhododendron

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Horticultural Plant Journal 2024年第3期10卷 866-878页

作者： Yuanting Shen Gang Yao Yunfei Li Xiaoling Tian shiming Li Nian Wang Chengjun Zhang Fei Wang yongpeng Ma Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China Beijing Genomics of Institute ShenzhenGuangdong 518120China Guiyang Institute of Humanities and Technology GuiyangGuizhou 550025China State Forestry and Grassland Administration Key Laboratory of Silviculture in Downstream Areas of the Yellow River College of ForestryShandong Agricultural UniversityTai'anShandong 271018China The Southwest China of Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China West China Subalpine Botanical Garden Institute of BotanyChinese Academy of SciencesChengduSichuan 611834China

Rhododendron is famous for its high ornamental ***,the genus is taxonomically difficult and the relationships within Rhododendron remain *** addition,the origin of key morphological characters with high horticulture value need to be *** problems largely hinder utilization of germplasm *** studies attempted to disentangle the phylogeny of Rhododendron,but only used a few genomic markers and lacked large-scale sampling,resulting in low clade support and contradictory phylogenetic ***,we used restriction-site associated DNA sequencing(RAD-seq)data and morphological traits for 144 species of Rhododendron,representing all subgenera and most sections and subsections of this species-rich genus,to decipher its intricate evolutionary history and reconstruct ancestral *** results revealed high resolutions at subgenera and section levels of Rhododendron based on RAD-seq *** optimal phylogenetic tree and split tree recovered five lineages among ***(cladeⅠ)formed the basal *** and Azaleastrum formed cladeⅡand had sister ***Ⅲincluded all scaly rhododendron ***(cladeⅣ)formed a sister group to ***(cladeⅤ).The results of ancestral state reconstruction showed that Rhododendron ancestor was a deciduous woody plant with terminal inflorescence,ten stamens,leaf blade without scales and broadly funnelform corolla with pink or purple *** study shows significant distinguishability to resolve the evolutionary history of Rhododendron based on high clade support of phylogenetic tree constructed by RAD-seq *** also provides an example to resolve discordant signals in phylogenetic trees and demonstrates the application feasibility of RAD-seq with large amounts of missing data in deciphering intricate evolutionary ***,the reconstructed ancestral state of six important characters provides insights into the inn

关键词： Rhododendron RAD-seq Missing data Quartet sampling(QS) Ancestral state reconstruction

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IEEE802．11协议性能增强和带宽保证机制的研究

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Journal of Computer Science & Technology 2004年第C期19卷 80-80页

作者： yongpeng shi-duancheng NationalLaboratoryofSwitchingTechnologyandTelecommunicationNetworks BeijingUniversityofPostsandTelecommunicationsBeijing100876P.R.China

由于用户应用的多样性，一些高层应用(如数据应用、视频应用以及语音)对带宽、时延和丢包率有不同的要求。在这些上层应用的推动下，需要对IEEE 802．11 DCF机制作相应的改动来提供QoS(Quality of Service)的支持。本文提出了一种机制... 详细信息

由于用户应用的多样性，一些高层应用(如数据应用、视频应用以及语音)对带宽、时延和丢包率有不同的要求。在这些上层应用的推动下，需要对IEEE 802．11 DCF机制作相应的改动来提供QoS(Quality of Service)的支持。本文提出了一种机制以保证分布式竞争环境下的无线局域网的服务质量。本文的创新点如下：

关键词：性能增强 IEEE802.11协议带宽保证无线局域网 DCF 视频应用时延丢包率分布式数据应用

Structure-regulated fluorine-containing additives to improve the performance of perovskite solar cells

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Nano Research 2024年第7期17卷 6080-6086页

作者： Peiya Chen Xiaoman Bi Hao Yan Yingjie Zhao Yihao Liu Zhuo Huang Qian Xiao yongpeng Yang Shasha Zhang Yiqiang Zhang Yanlin Song Henan Institute of Advanced Technology College of ChemistrySchool of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing CAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyNational Laboratory for Molecular Sciences(BNLMS)Beijing 100190China

Perovskite solar cells(PSCs)have seen remarkable progress in recent years,largely attributed to various additives that enhance both efficiency and *** these,fluorine-containing additives have garnered significant interest because of their unique hydrophobic properties,effective defect passivation,and regulation capability on the crystallization ***,a targeted structural approach to design such additives is necessary to further enhance the performance of ***,fluoroalkyl ethylene with different fluoroalkyl chain lengths(CH_(2)CH(CF_(2))nCF_(3),n=3,5,and 7)as liquid additives is used to investigate influences of fluoroalkyl chain lengths on crystallization regulation and defect *** findings indicate that optimizing the quantity of F groups plays a crucial role in regulating the electron cloud distribution within the additive *** optimization fosters strong hydrogen bonds and coordination effects with FA+and uncoordinated Pb^(2+),ultimately enhancing crystal quality and device ***,1H,1H,2H-perfluoro-1-hexene(PF_(3))with the optimal number of F presents the most effective modulation effect.A PSC utilizing PF_(3)achieves an efficiency of 24.05%,and exhibits exceptional stability against humidity and thermal *** work sheds light on the importance of tailored structure designs in additives for achieving high-performance PSCs.

关键词： perovskite solar cells fluorine number additive structure crystallization regulation defect passivation

Adaptive Space Expansion for Fast Motion Planning

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1499-1514页

作者： Shenglei shi Jiankui Chen State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning *** this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible *** ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary ***,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is ***,the ASE method successively does space exploring and space expan-sion until the final path has been ***,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in *** last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE *** demon-strate that the computation speed is much faster than that of the state-of-the-art *** source codes are available at https://***/shshlei/ompl.

关键词： Adaptive space expansion(ASE) hyper-ellipsoid ring informed sampling motion planning.

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