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Pedosphere 2023年第6期33卷 916-926页

作者： Yosef STEINBERGER Dorsaf KERFAHI Tirza DONIGER chen sherman Itaii APPLEBAUM Gil ESHEL The Mina&Everard Goodman Faculty of Life Sciences Bar-Ilan UniversityRamat Gan 5290002Israel School of Natural Sciences Department of Biological SciencesKeimyung UniversityDaegu 42601Korea Soil Erosion Research Station Ministry of Agriculture&Rural DevelopmentP.O.Box 30Beit-Dagan 5020000Israel

Soil biota play a crucial role in soil ecosystem stability, promoting organic matter decomposition and nutrient cycling. Compared to conventional farming,organic farming is known to improve soil properties such as aggregation. Despite the importance of soil microbial communities in soil biogeochemical processes, our knowledge of their dynamics is rudimentary, especially under different agricultural management practices. Here we studied the effects of vineyard management practices(conventional and organic) and soil aggregate fractions(micro-, meso-, and macroaggregates) on free-living soil *** abundance, diversity, and ecological indices, such as the Wasilewska index and trophic diversity, of free-living soil nematodes were determined. We found that the abundance of free-living soil nematodes was increased by organic farming. In addition, plant parasites were found to increase in macroaggregates in the organic plot, which may be attributed to the weeds present due to no-tillage and no herbicides. Nematode family network connectivity increased in complexity with increasing aggregate size, highlighting the importance of the interplay between nematodes and soil inter-aggregate pore size and connectivity.

关键词： aggregate size agroecosystem ecological index network connectivity soil habitat tllage trophic group

Profiling soil free-living nematodes in the Namib Desert, Namibia

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Journal of Arid Land 2020年第1期12卷 130-143页

作者： Eugene MARAIS Gillian MAGGS-KÖLLING chen sherman Tirza DONIGER LIURentao Binu M TRIPATHI Yosef STEINBERGER Gobabeb Research and Training Centre Walvis BayGobabeb 953Namibia The Mina&Everard Goodman Faculty of Life Sciences Bar-Ilan University Ramat-Gan 5290002Israel Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwestern China of Ministry of Education Ningxia UniversityYinchuan 750021China Korea Polar Research Institute Incheon 21990Korea

Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling *** objective of this study was to compare the composition,abundance and tropic group of soil free-living nematodes in the upper 0–10 cm soil layer under the male and female Acanthosicyos horridus *** *** and in the inter-shrub open areas(control)in the Namib Desert,Namibia in April *** moisture,organic matter(OM)and pH was also ***-living nematodes were extracted from 100 g soil using the Baermann funnel procedure,and total number of nematodes was counted under a *** composition and diversity of soil free-living nematodes were analyzed using 18S rDNA *** indicated that a total of 67 groups,including 64 species,2 genera and 1 family were *** behavior of 58 species were identified as follows:15 bacteria-feeding species,12 fungi-feeding species,10 plant-parasite species,5 omnivorous-predator species,8 animal-parasite species,5 invertebrate-parasite species and 3 non-free-living nematodes,known as marine ***,soil free-living nematodes were found to be affected by sampling locations and plant gender,and community composition and density of these nematodes were strongly influenced by soil OM *** confirmed that spatial location and plant cover were main factors influencing the diversity of soil free-living ***,molecular tools were found to be very useful in defining the richness of soil non-free-living *** conclusion,the results elucidated the importance of biotic variables in determining the composition and abundance of soil free-living nematodes in the Namib Desert,Namibia.

关键词： plant gender plant cover nematodes trophic group diversity 18S rDNA

Changes in soil free-living nematode communities and their trophic composition along a climatic gradient

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Open Journal of Ecology 2012年第2期2卷 79-89页

作者： Tal Levi chen sherman Stanislav Pen-Mouratov Yosef Steinberger The Mina & Everard Goodman Faculty of Life Sciences Bar-Ilan University Ramat-Gan Israel

Ambiguity exists concerning the effects of climate on soil nematode-community composition. In this study, we examined the free-living nematode communities in soil along a climatic gradient representing humid-Mediterranean, Mediterranean, semi-arid, and arid climate types. The relationships between abiotic soil characteristics (organic carbon, soil moisture (SM), water-holding capacity) and nematode parameters, such as abundance, trophic group composition, and diversity indices, were explored in the context of climate and seasonality. Nematode abundance was lowest at the arid site. At the humid Mediterranean and Mediterranean locations, nematode abundance reached its peak in winter, while at the semi-arid and arid sites, an almost opposite trend was observed, with lowest abundances in winter, presumably due to a nutrient washout from the soil profile during the rainy season. On the trophic level, one trophic group demonstrated a positive correlation with SM and one trophic group demonstrated a negative one at each location, while the other two groups remained constant. Fungi-feeding nematodes were found to be unaffected by SM at the humid-Mediterranean and Mediterranean locations, while at the semi-arid and arid sites their proportion increased in correlation with decreasing SM. Bacteria-feeders increased with SM at the arid site, were unaffected at the semi-arid location, and decreased with SM at the humid-Mediterranean and Mediterranean sites. Plant-parasites were associated with SM only at the humid-Mediterranean site. Omnivores-predators were positively affected by SM at the two middle locations, staying constant at the humid-Mediterranean and arid sites. These findings point to the strong linkage existing between nematode trophic behavior and climatic factors, demonstrating distinctive communal fingerprints for each climate type.

关键词： Climate Gradient Diversity Soil Nematode Trophic Group

Learning-Based Joint Resource Slicing and Scheduling in Space-Terrestrial Integrated Vehicular Networks

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Journal of Communications and Information Networks 2021年第3期6卷 208-223页

作者： Huaqing Wu Jiayin chen Conghao Zhou Junling Li Xuemin(sherman)Shen Department of Electrical and Computer Engineering University of WaterlooWaterloo.ON N2L 3G1Canada Department of Electrical and Computer Engineering the University of British ColumbiaVancouverBC V6T 1Z4Canada Shenzhen Institute of Artificial Intelligence and Robotics for Society(AIRS) and the Department of Electrical and Computer EngineeringUniversity of WaterlooCanada

In this paper,we investigate the resource slicing and scheduling problem in the space-terrestrial integrated vehicular networks to support both delay-sensitive services(DSSs)and delay-tolerant services(DTSs).Resource slicing and scheduling are to allocate spectrum resources to different slices and determine user association and bandwidth allocation for individual *** accommodate the dynamic network conditions,we first formulate a joint resource slicing and scheduling(JRSS)problem to minimize the long-term system cost,including the DSS requirement violation cost,DTS delay cost,and slice reconfiguration *** resource slicing and scheduling decisions are interdependent with different timescales,we decompose the JRSS problem into a large-timescale resource slicing subproblem and a small-timescale resource scheduling *** propose a two-layered reinforcement learning(RL)-based JRSS scheme to find the solutions to the *** the resource slicing layer,spectrum resources are pre-allocated to different slices via a proximal policy optimization-based RL *** the resource scheduling layer,spectrum resources in each slice are scheduled to individual vehicles based on dynamic network conditions and service requirements via matching-based *** conduct extensive trace-driven experiments to demonstrate that the proposed scheme can effectively reduce the system cost while satisfying service quality requirements.

关键词： space-terrestrial integrated vehicular networks LEO satellite communication resource slicing and scheduling reinforcement learning matching-based optimization

Channel-Feedback-Free Transmission for Downlink FD-RAN:A Radio Map Based Complex-Valued Precoding Network Approach

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China Communications 2024年第4期21卷 10-22页

作者： Zhao Jiwei chen Jiacheng Sun Zeyu Shi Yuhang Zhou Haibo Xuemin(sherman)Shen School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310058China Department of Mathematics and Theories Peng Cheng LaboratoryShenzhen 518000China Department of Electrical and Computer Engineering University of WaterlooWaterlooOntarioN2L 3G1Canada

As the demand for high-quality services proliferates,an innovative network architecture,the fully-decoupled RAN(FD-RAN),has emerged for more flexible spectrum resource utilization and lower network ***,with the decoupling of uplink base stations and downlink base stations in FDRAN,the traditional transmission mechanism,which relies on real-time channel feedback,is not suitable as the receiver is not able to feedback accurate and timely channel state information to the *** paper proposes a novel transmission scheme without relying on physical layer channel ***,we design a radio map based complex-valued precoding network(RMCPNet)model,which outputs the base station precoding based on user *** comprises multiple subnets,with each subnet responsible for extracting unique modal features from diverse input ***,the multimodal embeddings derived from these distinct subnets are integrated within the information fusion layer,culminating in a unified *** also develop a specific RMCPNet training algorithm that employs the negative spectral efficiency as the loss *** evaluate the performance of the proposed scheme on the public DeepMIMO dataset and show that RMCPNet can achieve 16%and 76%performance improvements over the conventional real-valued neural network and statistical codebook approach,respectively.

关键词： beamforming complex neural networks deep learning FD-RAN

Internet of Vehicles in Big Data Era

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 19-35页

作者： Wenchao Xu Haibo Zhou Nan cheng Feng Lyu Weisen Shi Jiayin chen Xuemin (sherman) Shen Department of Electrical and Computer Engineering University of Waterloo Waterloo Ontario N2L 3G1 Canada School of Electronic Science and Engineering Nanjing University Nanjing China Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China IEEE

As the rapid development of automotive telematics,modern vehicles are expected to be connected through heterogeneous radio access technologies and are able to exchange massive information with their surrounding environment. By significantly expanding the network scale and conducting both real-time and long-term information processing, the traditional Vehicular AdHoc Networks(VANETs) are evolving to the Internet of Vehicles(Io V), which promises efficient and intelligent prospect for the future transportation system. On the other hand, vehicles are not only consuming but also generating a huge amount and enormous types of data, which is referred to as Big Data. In this article, we first investigate the relationship between Io V and big data in vehicular environment, mainly on how Io V supports the transmission, storage, computing of the big data, and how Io V benefits from big data in terms of Io V characterization,performance evaluation and big data assisted communication protocol design. We then investigate the application of Io V big data in autonomous vehicles. Finally, the emerging issues of the big data enabled Io V are discussed.

关键词： Autonomous vehicles big data big data applications data communication IoV vehicular networks

Cybertwin-Assisted Mode Selection in Ultra-Dense LEO Integrated Satellite-Terrestrial Network

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Journal of Communications and Information Networks 2022年第4期7卷 360-374页

作者： Xin Zhang Bo Qian Xiaohan Qin Ting Ma Jiachen chen Haibo Zhou Xuemin(sherman)Shen School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China Laboratory Shenzhen 518000China Department of Electrical and Computer Engineering University of WaterlooWaterlooON N2L 3G1Canada

Ultra-dense low earth orbit(LEO)integrated satellite-terrestrial network(ULISTN)has become an emerging paradigm to support massive access of Internet of things(IoT)in beyond fifth generation mobile networks(B5G).In ULISTN,there are two communication modes:cellular mode and satellite mode,where IoT users assessing terrestrial small base stations(TSBSs)and terrestrial-satellite terminals(TSTs)***,how to optimize the network performance and guarantee self-interests of the operator and IoT users in ULISTN is a challenging *** this paper,we propose a cybertwin-assisted joint mode selection and dynamic pricing(JMSDP)scheme for effective network management in ULISTN,where cybertwin serves as the intelligent *** JMSDP,the operator determines optimal access prices of TSBSs and TSTs,while each user selects the access mode according to access ***,the operator conducts the Stackelberg game aiming at maximizing average throughput depending on the mode selection results of IoT ***,IoT users as followers adopt the evolutionary game to choose an access mode based on the access prices provided by the *** results show that the proposed JMSDP can improve the average throughput and reduce the delay effectively,comparing with random access(RA)and maximum rate access.

关键词： ULISTN massive IoT cybertwin mode selection dynamic pricing game theory

Database-Assisted Dynamic Spectrum Access with QoS Guarantees:A Double-Phase Auction Approach

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China Communications 2015年第1期12卷 66-77页

作者： ZHOU Haibo LIU Bo HOU Fen ZHANG Ning GUI Lin chen Jiacheng Xuemin(sherman) Shen Shanghai Jiao Tong University University of Waterloo University of Macao

Since FCC's opening for white space(WS) utilization,database-assisted dynamic spectrum access(DSA) has become the de facto solution for the realization of dynamic spectrum sharing(DSS),due to its simplicity and compatibility with commercial off-the-shelf(COTS) *** is envisioned that such technology will strongly support the prosperous wireless multimedia networking(WMN) applications with satisfying QoS guarantees in the ***,how to counter the time-frequency variant property when exploiting the WS spectrum for the provision of these services to secondary users(SUs) still remains a great *** such context,a dynamic secondary access scheme for database-assisted spectrum sharing networks is proposed in this *** the beginning,the spectrum requirements of SUs for diverse services are modeled by considering the minimum required service data-rate and spectrum access ***,the spectrum demand evaluation and bidding policy are formulated based on the service classes of ***,a doublephase(DP) spectrum allocation scheme,which consists of the initial resource allocation phase and resource allocation adjustment phase,is carefully designed for ***,extensive simulations are conducted and the results demonstrate that our scheme can increase the spectrum trading revenue and adapt to varying service requirements.

关键词： dynamic spectrum allocation quality of service white-space spectrum secondary access networks

The Impacts of COVID-19 on Migrants,Remittances,and Poverty in China:A Microsimulation Analysis

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China & World Economy 2021年第6期29卷 4-33页

作者： Yumei Zhang Yue Zhan Xinshen Diao Kevin Z.chen sherman Robinson Institute of Agricultural Economics and Development Chinese Academy of Agricultural SciencesChina International Food Policy Research Institute(IFPRI) China China Academy for Rural Development Zhejiang UniversityChina

Chinese migrant workers are very exposed to the shocks caused by the COVID-19 *** remittances adversely affect their families who rely on remittance *** impacts of COVID-19 on migrants and remittance-receiving households are assessed using a nationally representative household dataset and a microsimulation *** found about 70 percent of migrant workers lost part of their wage income during the pandemic lockdown period and rural migrants working in small and medium enterprises were affected the *** led to about 50 percent of remittance-receiving households being affected adversely by falling remittances,and the average decline in such income was more than 45 *** 13 percent of pre-pandemic nonpoor remittance-receiving households could fall into poverty,raising the poverty rate among remittancereceiving households by 4 percentage *** households that were poor prior to the pandemic became more *** results indicate that social protection programs targeting vulnerable migrants and their families at home are important.

关键词： China COVID-19 microsimulation migrants and remittances poverty

Reconfigurable intelligent surfaces for smart wireless environments: channel estimation, system design and applications in 6G networks

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Science China(Information Sciences) 2021年第10期64卷 52-72页

作者： Ying-Chang LIANG Jie chen Ruizhe LONG Zhen-Qing HE Xianqi LIN chenlu HUANG Shilin LIU Xuemin (sherman) SHEN Marco DI RENZO Center for Intelligent Networking and Communications University of Electronic Science and Technology of China School of Electronic Science and Engineering University of Electronic Science and Technology of China Department of Electrical and Computer Engineering University of Waterloo Université Paris-Saclay CNRS CentraleSupélec Laboratoire des Signaux et Systèmes

Reconfigurable intelligent surface(RIS), one of the key enablers for the sixth-generation(6G)mobile communication networks, is considered by designers to smartly reconfigure the wireless propagation environment in a controllable and programmable manner. Specifically, an RIS consists of a large number of low-cost and passive reflective elements(REs) without radio frequency chains. The system gain of RIS wireless systems can be achieved by adjusting the phase shifts and amplitudes of the REs so that the desired signals can be added constructively at the receiver. However, an RIS typically has limited signal processing capability and cannot perform active transmitting/receiving in general, which leads to new challenges in the physical layer design of RIS wireless systems. In this paper, we provide an overview of the RIS-aided wireless systems, including the reflection principle, channel estimation, and system design. In particular,two types of emerging RIS systems are considered: RIS-aided wireless communications(RAWC) and RISbased information transmission(RBIT), where the RIS plays the role of the reflector and the transmitter,respectively. We also envision the potential applications of RIS in 6G networks.

关键词： reconfigurable intelligent surface channel estimation RIS-aided wireless communications RIS-based information transmission 6G