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21篇 您的检索式:作者名="CHENG GuoZhen"
    题名 作者 年代 出处 被引量
1A Game-Theoretic Approach to Elastic Control in Software-Defined Networking显示文摘Elastic control could balance the distributed control plane in Software-Defined Networking(SDN). Dynamic switch migration has been proposed to achieve it. However, existing schemes mainly focus on how to execute migration operation, but not why. This paper designs a decision-making mechanism based on zero-sum game theory to reelect a new controller as the master for migrated switches. It first chooses a switch for migration in the heavy controller which invites its neighbors as the game players to compete for the master role of this switch in the game-playing field(GPF) which is an occasional and loose domain for game-playing. Second, based on the concept of GPF, we design a decentralized strategy to play the game and determine which player as the final master. We implement it by extending the Open Flow protocol. Finally, numerical results demonstrate that our distributed strategy can approach elastic control plane with better performance.Hongchang Chen Guozhen Cheng Zhiming Wang 2016China Communications2016,13,5:5
2Nanosecond photoelectric effects in all-oxide p-n junction of La_(0.9)Sr_(0.1)MnO_(3)/SrNb_(0.01)Ti_(0.99)O_(3)显示文摘Nanosecond (ns) photoelectric effects have been observed in all-oxide p-n junctions of La0.9Sr0.1MnO3/SrNb0.01Ti0.99O3 for the first time. The rise time was about 23 ns and the full width at half maximum was about 125 ns for the open-circuit photovoltaic pulse when the La0.9Sr0.1MnO3 thin film in the p-n junction was irradiated by a laser of ~20 ns pulse duration and 308 nm wavelength. The photovoltaic sensitivity was 80 mV/mJ for a 308 nm laser pulse.HUANG Yanhong L(U) Huibin HE Meng ZHAO Kun CHEN Zhenghao CHENG Bolin ZHOU Yueliang JIN Kuijuan DAI Shouyu YANG Guozhen 2005Science China(Physics,Mechanics & Astronomy)2005,48,3:4
3An Aware-Scheduling Security Architecture with Priority-Equal Multi-Controller for SDN显示文摘Current SDN controllers suffer from a series of potential attacks. For example, malicious flow rules may lead to system disorder by introducing unexpected flow entries. In this paper, we propose Mcad-SA, an aware decision-making security architecture with multiple controllers, which could coordinate heterogeneous controllers internally as a 'big' controller. This architecture includes an additional plane, the scheduling plane, which consists of transponder, sensor, decider and scheduler. Meanwhile it achieves the functions of communicating, supervising and scheduling between data and control plane. In this framework, we adopt the vote results from the majority of controllers to determine valid flow rules distributed to switches. Besides, an aware dynamic scheduling(ADS) mechanism is devised in scheduler to intensify security of Mcad-SA further. Combined with perception, ADS takes advantage of heterogeneity and redundancy of controllers to enable the control plane operate in a dynamic, reliable and unsteady state, which results in significant difficulty of probing systems and executing attacks. Simulation results demonstrate the proposed methods indicate better security resilience over traditional architectures as they have lower failure probability when facing attacks.Chao Qi Jiangxing Wu Guozhen Cheng Jianjian Ai Shuo Zhao 2017China Communications2017,14,9:4
4An Approach for Network Function Combination Based on Least Busy Placement Algorithm显示文摘Recently, integrating Softwaredefined networking(SDN) and network functions virtualization(NFV) are proposed to address the issue that difficulty and cost of hardwarebased and proprietary middleboxes management. However, it lacks of a framework that orchestrates network functions to service chain in the network cooperatively. In this paper, we propose a function combination framework that can dynamically adapt the network based on the integration NFV and SDN. There are two main contributions in this paper. First, the function combination framework based on the integration of SDN and NFV is proposed to address the function combination issue, including the architecture of Service Deliver Network, the port types representing traffic directions and the explanation of terms. Second, we formulate the issue of load balance of function combination as the model minimizing the standard deviations of all servers' loads and satisfying the demand of performance and limit of resource. The least busy placement algorithm is introduced to approach optimal solution of the problem. Finally, experimental results demonstrate that the proposed method can combine functions in an efficient and scalable way and ensure the load balance of the network.XIE Lijun JIANG Yiming WANG Binqiang XIONG Gang CHENG Guozhen 2016China Communications2016,13,S1:3
5Community-level trait responses and intra-specific trait variability play important roles in driving community productivity in an alpine meadow on the Tibetan Plateau显示文摘Aims Human activities have dramatically increased nutrient inputs to ecosys-tems,impacting plant community diversity,composition and function-ing.Extensive research has shown that a decrease in species diversity and an increase in productivity are a common phenomenon following fertilization in grasslands ecosystem.The magnitude of the response of species diversity and above-ground net primary productivity(ANPP)to fertilization mainly depends on species traits(mean trait values)and traits variability(plasticity).Our aim of this study was to examine(i)changes of species diversity(species richness and Shannon-Wiener index)and ANPP following fertilization;(ii)which species traits or community-weighted mean(CWM)traits can determine ANPP,as expected from the‘biomass ratio hypothesis’;and(iii)the relative role of intra-specific and inter-specific trait variability in this process following fertilization.Methods We measured ANPP and four key plant functional traits:specific leaf area(SLA),leaf dry matter content(LDMC),mature plant height(MPH)and leaf nitrogen concentration(LNC)for 25 component species along a fertilization gradient in an alpine meadow on the Tibetan Plateau.In addition,trait variation of species was assessed using coefficients of variation(CV),and we calculated the ratio of the CVintra to the CVinter.Important Findings Our results showed that:(i)fertilization significantly reduced species richness and Shannon-Weiner diversity index,but sig-nificantly increased ANPP;(ii)there was a significant positive correlation between ANPP and CWM-SLA and CWM-MPH,yet there was no significant relationship between ANPP and CWM-LNC or CWM-LDMC;(iii)intra-specific variability in SLA and MPH was found to be much greater than inter-specific variability,especially at the higher fertilization levels.We con-cluded that CWM-SLA and CWM-MPH can be used to assess the impacts of species changes on ecosystem functioning,and dominant species can maximize resource use through intra-spe-cific variability in SLA and MPH to compensate for the loss of species following fertilization,therefore maintaining high com-munity productivity.Wei Li Jie Zhao Howard E.Epstein Guanghua Jing Jimin Cheng Guozhen Du 2017Journal of Plant Ecology2017,10,4:3
6Effect of electroacpuncture of Neiguan(PC 6)and Tianquan(PC 2)on skin temperature,blood perfusion,and adrenoceptor response in rats with acute myocardial ischemia显示文摘OBJECTIVE: To investigate the effect of electroacupuncture(EA) of acupoints Neiguan(PC 6) and Tianquan(PC 2) on the skin temperature, blood perfusion, and alpha1-and beta2-adrenoreceptor(α1-AR and β2-AR) protein and m RNA level in rats with acute myocardial ischemia.METHODS: Thirty male adult Wistar rats [(230 ±20) g] were randomly assigned into five groups(n = 6 each): a control group, sham operation group, model group, model group treated with EA at low frequency(L-EA, 2 Hz, 1 m A) and model group treated with EA at high frequency(H-EA, 100 Hz, 1 m A). The rat model was prepared by ligating the left anterior descending coronary artery. Electroacupuncture was performed at the left Neiguan(PC 6) for 20 min daily for 3 d. After the 3 rd time of the treatment, measurements of skin blood perfusion and temperature in Neiguan(PC 6) and Tianquan(PC 2) in all groups were made by laser speckle contrast imaging and infrared thermal image instrument. Real-time PCR and ELISA were used to measure m RNA level and protein level of α1-AR andβ2-AR in the skin tissues of Neiguan(PC 6) and Tianquan(PC 2), respectively. Serum levels of c Tn T and electrocardiogram were used to identify the state of myocardium.RESULTS: In the group receiving electroacupunture at Neiguan(PC 6), compared with control group,the skin temperature, blood perfusion, and β2-AR m RNA and protein level of model group significantly decreased(P < 0.05), α1-AR m RNA and protein level of model group significantly increased(P < 0.05);compared with model group, the skin temperature,blood perfusion, and β2-AR m RNA and protein level of L-EA significantly increased(P < 0.05), α1-AR m RNA and protein level of L-EA and H-EA significantly decreased(P < 0.05). The same trend has taken place in the former four groups of the Tianquan(PC 2).CONCLUSION: Low-or high-frequency electroacupuncture can improve the skin temperature and blood perfusion which may be induced by decreasingthelevelofα1-ARandincreasingthelevelofβ2-AR of the Neiguan(PC 6) and Tianquan(PC 2) in the rat with acute myocaidial ischemia.Wang Dan Ji Bo Zhao Guozhen Yan Mingna Bai Hongxin Sun Xiaomin Dai Jian Lu Yawen Liu Yitian You Min Wu Jiaojuan Ge Yunpeng Su Hang Cheng Kai 2017Journal of Traditional Chinese Medicine2017,37,6:3
7Design and Implementation of an SDN-Enabled DNS Security Framework显示文摘The Domain Name System(DNS) is suffering from the vulnerabilities exploited to launch the cache poisoning attack. Inspired by biodiversity, we design and implement a non-intrusive and tolerant secure architecture Multi-DNS(MDNS) to deal with it. MDNS consists of Scheduling Proxy and DNS server pool with heterogeneous DNSs in it. And the Scheduling Proxy dynamically schedules m DNSs to provide service in parallel and adopts the vote results from majority of DNSs to decide valid replies. And benefit from the centralized control of software defined networking(SDN), we implement a proof of concept for it. Evaluation results prove the validity and availability of MDNS and its intrusion/fault tolerance, while the average delay can be controlled in 0.3s.Zhenpeng Wang Hongchao Hu Guozhen Cheng 2019China Communications2019,16,2:3
8Toward a Scalable SDN Control Mechanism via Switch Migration显示文摘Dynamic Controller Provisioning Problem(DCPP) is a key problem for scalable SDN. Previously, the solution to this problem focused on adapting the number of controllers and their locations with changing network conditions, but ignored balancing control loads via switch migration. In this paper, we study a scalable control mechanism to decide which switch and where it should be migrated for more balanced control plane, and we define it as Switch Migration Problem(SMP). The main contributions of this paper are as follows. First, we define a SDN model to describe the relation between controllers and switches from the view of loads. Based on this model, we form SMP as a Network Utility Maximization(NUM) problem with the objective of serving more requests under available control resources. Second, we design a synthesizing distributed algorithm for SMP--- Distributed Hopping Algorithm(DHA), by approximating our optimal objective via Log-Sum-Exp function. In DHA, individual controller performs algorithmic procedure independently. With the solution space F, we prove that the optimal gap caused by approximation is at most 1/βlog|F|, and DHA procedure is equal to implementation of a time-reversible Markov Chain process. Finally, the results are corroborated by several numerical simulations.Guozhen Cheng Hongchang Chen Hongchao Hu Zhiming Wang 2017China Communications2017,14,1:3
9Enabling network function combination via service chain instantiation显示文摘Guozhen Cheng Hongchang Chen Hongchao Hu Zhiming Wang Julong Lan 2015Computer Networks2015,,:2
10SecIngress:An API Gateway Framework to Secure Cloud Applications Based on N-Variant System显示文摘Based on the diversified technology and the cross-validation mechanism,the N-variant system provides a secure service architecture for cloud providers to protect the cloud applications from attacks by executing multiple variants of a single software in parallel and then checking their behaviors’consistency.However,it is complex to upgrade current Software as a Service(SaaS)applications to adapt N-variant system architecture.Challenges arise from the inability of tenants to adjust the application architecture in the cloud environment,and the difficulty for cloud service providers to implement N-variant systems using existing API gateways.This paper proposes SecIngress,an API gateway framework,to overcome the challenge that it is hard in the cloud environment to upgrade the applications based on N-variants system.We design a two-stage timeout processing method to lessen the service latency and an Analytic Hierarchy Process Voting under the Metadata mechanism(AHPVM)to enhance voting accuracy.We implement a prototype in a testbed environment and analyze the security and performance metrics before and after deploying the prototype to show the effectiveness of SecIngress.The results reveal that SecIngress enhances the reliability of cloud applications with acceptable performance degradation.Dacheng Zhou Hongchang Chen Guozhen Cheng Weizhen He Lingshu Li 2021China Communications2021,18,8:2
11Towards a Dynamic Controller Scheduling-Timing Problem in Software-Defined Networking显示文摘Controller vulnerabilities allow malicious actors to disrupt or hijack the Software-Defined Networking. Traditionally, it is static mappings between the control plane and data plane. Adversaries have plenty of time to exploit the controller's vulnerabilities and launch attacks wisely. We tend to believe that dynamically altering such static mappings is a promising approach to alleviate this issue, since a moving target is difficult to be compromised even by skilled adversaries. It is critical to determine the right time to conduct scheduling and to balance the overhead afforded and the security levels guaranteed. Little previous work has been done to investigate the economical time in dynamic-scheduling controllers. In this paper, we take the first step to both theoretically and experimentally study the scheduling-timing problem in dynamic control plane. We model this problem as a renewal reward process and propose an optimal algorithm in deciding the right time to schedule with the objective of minimizing the long-term loss rate. In our experiments, simulations based on real network attack datasets are conducted and we demonstrate that our proposed algorithm outperforms given scheduling schemes.Zhenping Lu Fucai Chen Guozhen Cheng Chao Qi Jianjian Ai 2017China Communications2017,14,10:2
12Orchestrating Network Functions in Software-Defined Networks显示文摘Software.defined networking(SDN) enables third.part companies to participate in the network function innovations. A number of instances for one network function will inevitably co.exist in the network. Although some orchestration architecture has been proposed to chain network functions, rare works are focused on how to optimize this process. In this paper, we propose an optimized model for network function orchestration, function combination model(FCM). Our main contributions are as following. First, network functions are featured with a new abstraction, and are open to external providers. And FCM identifies network functions using unique type, and organizes their instances distributed over the network with the appropriate way. Second, with the specialized demands, we can combine function instances under the global network views, and formulate it into the problem of Boolean linear program(BLP). A simulated annealing algorithm is designed to approach optimal solution for this BLP. Finally, the numerical experiment demonstrates that our model can create outstanding composite schemas efficiently.Hongchao Hu Lin Pang Zhenpeng Wang Guozhen Cheng 2017China Communications2017,14,2:2
13Osteosarcoma metastasis: prospective role of ezrin显示文摘Yuanjin Zhang Ling Zhang Guofu Zhang Songbai Li Jun Duan Jie Cheng Guozhen Ding Chibing Zhou Jie Zhang Pengcheng Luo Dongbing Cai Lianghong Kuang Yichun Zhou Liqun Tong Xiangdong Yu Lifang Zhang Lijun Xu Li Yu Xiaomei Shi Aihong Ke 2014Tumor Biology2014,,6:1
14Short-term responses of an alpine meadow community to removal of a dominant species along a fertilization gradient显示文摘Aims The relationship between biodiversity and ecosystem functioning has intrigued ecologists for several decades,but the effect of loss of a dominant species on community structure and functioning along a nutrient gradient remains poorly understood.The aim of this paper was to test the effect of a dominant species on community structure and function by conducting a species removal experiment along a fertilization gradient.Methods We removed the population of a dominant species(Elymus nutans)in a long-term fertilization field in an alpine meadow on the Tibetan Plateau,China.univariate general linear models were used to evaluate the effects of fertilization and removal on above-ground vegetation characteristics,including photosynthetically active radiation in the understory,species richness,shannon-Weiner diversity index,simpson’s dominance index,above-ground biomass(includ-ing different functional groups)and seedling richness and density.Important Findingsresults revealed that after two plant growing seasons,there was no significant effect of the removal of a dominant species on species richness and diversity of the remaining vegetation,but the biomass of forbs and seedling recruitment were significantly increased indicative of the potential for long-term effects.moreover,removal had a large effect at high fertilization levels,but little effect when fertilization levels were low.our studies indicated that community response to loss of a dominant species was mainly dependent on resource availability and the remaining functional group identities.We also found seedling recruitment was usually more sensitive to the influence of competition of dominant species than the estab-lished vegetation in the short term.Wei Li Jimin Cheng Kailiang Yu Howard E.Epstein Guozhen Du 2015Journal of Plant Ecology2015,8,5:1
15Multiplexed Profiling of Extracellular Vesicles for Biomarker Development显示文摘Extracellular vesicles(EVs)are cell-derived membranous particles that play a crucial role in molecular trafficking,intercellular transport and the egress of unwanted proteins.They have been implicated in many diseases including cancer and neurodegeneration.EVs are detected in all bodily fluids,and their protein and nucleic acid content offers a means of assessing the status of the cells from which they originated.As such,they provide opportunities in biomarker discovery for diagnosis,prognosis or the stratification of diseases as well as an objective monitoring of therapies.The simultaneous assaying of multiple EV-derived markers will be required for an impactful practical application,and multiplexing platforms have evolved with the potential to achieve this.Herein,we provide a comprehensive overview of the currently available multiplexing platforms for EV analysis,with a primary focus on miniaturized and integrated devices that offer potential step changes in analytical power,throughput and consistency.Cheng Jiang Ying Fu Guozhen Liu Bowen Shu Jason Davis George K.Tofaris 2022Nano-Micro Letters2022,14,1:1
16Defending Against Link Failure in Virtual Network Embedding Using a Hybrid Scheme显示文摘Nowadays network virtualization is utterly popular.As a result,how to protect the virtual networks from attacking on the link is increasingly important.Existing schemes are mainly backup-based,which suffer from data loss and are helpless to such attacks like data tampering.To offer high security level,in this paper,we first propose a multipath and decision-making(MD) scheme which applies multipath simultaneously delivery and decision-making for protecting the virtual network.Considering different security requirement for virtual link,we devise a hybrid scheme to protect the virtual links.For the critical links,MD scheme is adopted.For the other links,we adopt the Shared Backup Scheme.Our simulation results indicate the proposed scheme can significantly increase the security level of the critical link high in the loss of less acceptance ratio.Jianjian Ai Hongchang Chen Zehua Guo Guozhen Cheng 2019China Communications2019,16,1:1
17Central sensibility of human cases with different body mass during oral glucose tolerance test using functional magnetic resonance imaging显示文摘BACKGROUND: Because of the limitation of technique, there are few researches on regulating function o central hypothalamus by metabolism, especially the researches on real-time function. OBJECTIVE: To evaluate the response of hypothalamus to oral glucose tolerance test (OGTT) in differen body-weighted subjects by using functional magnetic resonance imaging (fMRI) so as to investigate th relationship between the sensitivity of hypothalamus in glycoregulation and disturbance of carbohydrat metabolism. DESIGN: Paired design. SETTING: Department of Radiology and Beijing Geriatrics Institute, Beijing Hospital, National Publi Health Bureau. PARTICIPANTS: A total of twenty healthy volunteers were selected from Beijing Geriatrics Institute National Public Health Bureau, including 10 subjects with obesity (5 males and 5 females; body mass > 28.0 kg/m2) and 10 subjects with normal body mass (5 males and 5 females; body mass from 18.5 to 23.9 kg/m2). All subjects gave written informed consent before participating in the study. METHODS: fMRI study was performed on GE 1.5 T Signa Twinspeed Infinity with Excite. Each voluntee was ingested of glucose during the fMRI scan. T2* images were acquired using a single-shot gradient echo (EPI) technique. The parameters of EPI included: TR 3 000 ms, TE 40 ms, Flip angle 90°, field of view (FOV) 24 cm × 24 cm, thickness 5 mm, gap 0 mm, matrix 64 × 64, number of excitation 1. All 10 subjects with normal body mass underwent a repeat fMRI scan after consuming an equivalent amount o water without glucose on a separate day. The procedure for the fMRI scan with water intake was the same a for glucose ingestion. fMRI data were processed with Intensity Averaging Method. MAIN OUTCOME MEASURES: The central response of hypothalamus and feedback orientation during OGTT in different body-weighted subjects. RESULTS: An acute transient decrease of fMRI intensity in posterior inferior and anterior inferior o hypothalamus was observed in all subjects within 2 minutes after oral glucose intake. This decrease wa followed by a recovery to the baseline. However, obese subjects had a delayed intensity decrease [(1.96± 1.06) minutes vs. (1.04±0.71) minutes, t =2.14, P < 0.05] and longer recovery time [(26.62±7.35 minutes vs. (16.29±6.42) minutes, t =3.67, P < 0.01] as compared with normal body-weight subjects Furthermore, decreased fMRI intensity was significant different from baseline intensity [(5.7±2.5)% vs (14.3±5.5)%, t =2.56, P < 0.05] in obese subjects, but not in normal body-weight subjects. The area o hypothalamus in normal body-weight volunteers demonstrated no significant signal change before and afte oral water ingestion (P > 0.05). CONCLUSION: Hypothalamus response to glucose loading is different in normal body-weighted and obes subjects. This suggests that fMRI is a useful tool to evaluate the central regulation of glucose metabolism.Min Chen Yunting Zhang Tiemei Zhang Cheng Zhou Xiaomeng Wu Kui Cai Zhenghan Yang Wenchao Wang Weifeng Zhao Saying Li Zhi Wang Guozhen Li 2007Neural Regeneration Research2007,2,9:1
18Survey on quantitative evaluations of moving target defense显示文摘Quantitative evaluations are of great importance in network security decision-making.In recent years,moving target defense(MTD)has appeared to be a promising defense approach that blocks asymmetrical advantage of attackers and favors the defender-notwithstanding,it has a limited deployment due to its uncertain efficiency and effectiveness in defense.In that case,quantitative metrics and evaluations of MTD are essential to prove its capability and impulse its further research.This article presents a comprehensive survey on state-of-the-art quantitative evaluations.First,taxonomy of MTD techniques is stated according to the software stack model.Then,a concrete review and comparison on existing quantitative evaluations of MTD is presented.Finally,notice-worthy open issues regarding this topic are proposed along with the conclusions of previous studies.Huanruo LI Yunfei GUO Shumin HUO Guozhen CHENG Wenyan LIU 2018网络与信息安全学报2018,4,9:1
19Improvement of Attributed Scattering Center Extraction by Using SAR Super-Resolution Preprocessing显示文摘Synthetic aperture radar(SAR)is able to acquire high-resolution method using the active microwave imaging method.SAR images are widely used in target recognition,classification,and surface analysis,with extracted features.Attribute scattering center(ASC)is able to describe the image features for these tasks.However,sidelobe effects reduce the accuracy and reliability of the estimated ASC model parameters.This paper incorporates the SAR super-resolution into the ASC extraction to improve its performance.Both filter bank and subspace methods are demonstrated for preprocessing to supress the sidelobe.Based on the preprocessed data,a reinforcement based ASC method is used to get the parameters.The experimental results show that the super-resolution method can reduce noise and suppress sidelobe effect,which improve accuracy of the estimated ASC model parameters.Guozhen Cheng Jiacheng Chen Fengming Hu Feng Xu 2023Journal of Beijing Institute of Technology2023,32,6:0
20Uncovering network traffic anomalies based on their sparse distributions显示文摘Characterizing network traffic with higher-dimensional features results in increased complexity of most detectors and classifiers for identifying traffic anomalies.Several key observations from existing studies confirm that network anomalies are typically distributed in a sparse way,with each anomaly essentially characterized by its lower-dimensional features.Based on this important finding,we exploit sparsity in designing a novel detection method for anomalies that ignores redundancies that are dynamically filtered from the feature sets and accurately classifies anomalies.Comparison of our method with three well known techniques shows a10%improvement in accuracy with an O(n)complexity of the classifier.CHENG GuoZhen CHEN HongChang CHENG DongNian ZHANG Zhen LAN JuLong 2014Science China(Information Sciences)2014,57,9:0
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