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Aerospace China 2016年第3期17卷 44-47页

作者： XIONG Ke State key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace Enigeering Nanjing University of Aeronauticsand Astronautics

·Prof.xiong,could you please give us a brief introduction to SKLMCMS?Director XIONG Ke:The State key Laboratory of Mechanics and Control of Mechanical Structures(SKLMCMS)was established with the approval of the Ministry of Science and Technology of the People’s Republic of China in October 2011.The laboratory is located at Nanjing University of Aeronautics and Astronautics(NUAA).The research areas of

关键词：实验室主任结构力学控制机械中华人民共和国国家重点实验室民族南京大学

Fault Tolerant Control Scheme Design for Formation Flight Control System of Multiple Unmanned Aerial Vehicles

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第4期35卷 693-701页

作者： Qian Moshu XIONG Ke College of Electrical Engineering and Control Science Nanjing Tech University State key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

The command tracking problem of formation flight control system(FFCS)for multiple unmanned aerial vehicles(UAVs)with sensor faults is discussed.And the objective of the addressed control problem is to design a robust fault tolerant tracking controller such that,for the disturbances and sensor faults,the closed-loop system is asymptotically stable with a given disturbance attenuation level.A robust fault tolerant tracking control scheme,combining an observer with H∞ performance,is proposed.Furthermore,it is proved that the designed controller can guarantee asymptotic stability of FFCS despite sensor faults.Finally,a simulation of two UAV formations is employed to demonstrate the effectiveness of the proposed approach.

关键词： formation control fault tolerant control(FTC) unmanned aerial vehicle(UAV) robust control

Application and Validation of a Multi-block Constitutive Model at Landslides of the Wenchuan Earthquake

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工程科学与技术 2018年第3期50卷 33-45页

作者： STAMATOPOULOS Constantine XIONG Ke DI Baofeng Stamatopoulos and Associates Limited Liability Company 5 Isavron Street Athens 114-71 Greece &Hellenic Open University Parodos Aristotelous 18 Patra 26335 Greece Institute for Disaster Management and Reconstruction Sichuan University Chengd

A multi-block model and a corresponding computer program have been developed which predict the kinematics of landslides.Furthermore,a unique event for studying different models simulating the triggering and movement of landslides is the 2008Wenchuan earthquake in the mountainous region in Sichuan Province of China,which caused a large number of rapid landslides.The purpose of the paper is two-fold:(a)to propose and incorporate into the multi-block model constitutive relations predicting soil response along slip surfaces,and(b)to apply the multi-block model with the constitutive relations at landslides triggered by the Wenchuan earthquake.The proposed constitutive equations predict the shape of the shear stress-displacement response measured in ring shear tests.In the application,four landslides caused by the Wenchuan earthquake were considered.Only in one of these landslides the shear resistance-displacement response along the slip surface has been measured in laboratory tests.At this landslide,the triggering and movement of the landslide was predicted.In the other landslides,back analyses were performed and it was observed that the multi-block model predicted reasonably well the final configuration of all slides.In addition,as the measured and back-estimated total friction angle of all landslides was less than 180,and the materials along the slip surface were sandy,it is inferred that some,or all of the slip surface during these slides was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and movement of these landslides.Concluding,the paper(A)proposed and validated a multi-block constitutive model which can be applied to predict the triggering and movement of earthquake-induced slides and(B)by analyzing four landslides of the 2008 Wenchuan earthquake,it concludes that some,or all of the slip surface during these slides,was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and m

关键词： Wenchuan earthquake multi-block model seismic displacement landslides back analysis strain softening

Age of Information Based User Scheduling and Data Assignment in Multi-User Mobile Edge Computing Networks:An Online Algorithm

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China Communications 2024年第5期21卷 153-165页

作者： Ge Yiyang XIONG Ke Dong Rui Lu Yang Fan Pingyi Qu Gang School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China Engineering Research Center of Network Management Technology for High Speed Railway of Ministry of Education Beijing 100044China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing 100044China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China Department of Electrical and Computer Engineering College ParkMarylandUSA

This paper investigates the age of information(AoI)-based multi-user mobile edge computing(MEC)network with partial offloading mode.The weighted sum AoI(WSA)is first analyzed and derived,and then a WSA minimization problem is formulated by jointly optimizing the user scheduling and data assignment.Due to the non-analytic expression of the WSA w.***.t.the optimization variables and the unknowability of future network information,the problem cannot be solved with known solution methods.Therefore,an online Joint Partial Offloading and User Scheduling Optimization(JPOUSO)algorithm is proposed by transforming the original problem into a single-slot data assignment subproblem and a single-slot user scheduling sub-problem and solving the two sub-problems separately.We analyze the computational complexity of the presented JPO-USO algorithm,which is of O(N),with N being the number of users.Simulation results show that the proposed JPO-USO algorithm is able to achieve better AoI performance compared with various baseline methods.It is shown that both the user’s data assignment and the user’s AoI should be jointly taken into account to decrease the system WSA when scheduling users.

关键词： age of information(aoi) mobile edge computing(mec) user scheduling

Association of polymorphisms in glutathione S-transferase genes （GSTM1, GSTT1, GSTP1） with idiopathic azoospermia or oligospermia in Sichuan, China

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Asian Journal of Andrology 2015年第3期17卷 481-486页

作者： Da-ke xiong key Laboratory of Bio-Resources and Eco-Environment Ministry of Education School of Life Science Institute of Medical Genetics Sichuan University Chengdu China Bio-resource Research and Utilization Joint key Laboratory of Sichuan and Chongqing Chengdu China Biotechnology Academy of Nanchuan Chongqing China

The reported effects of the glutathione S-transferase （GSTs） genes （GSTM1, GSTTI, and GSTP1） on male factor infertility have been inconsistent and even contradictory. Here, we conducted a case-control study to investigate the association between functionally important polymorphisms in GST genes and idiopathic male infertility. The study group consisted of 361 men with idiopathic azoospermia, 118 men with idiopathic oligospermia, and 234 age-matched healthy fertile male controls. Genomic DNA was extracted from the peripheral blood, and analyzed by polymerase chain reaction and restriction fragment length polymorphism analysis. There was a significant association between the GSTP1 variant genotype （lle/Val ＋ Val/Val） with idiopathic infertility risk （odds ratio [OR]： 1.53; 95% confidence interval [CI]： 1.11-2.11; P = 0.009）. Similarly, a higher risk of infertility was noted in individuals carrying a genotype combination of GSTTI-null and GSTP1 （lle/Val ＋ ValNal）（OR： 2.17; 95% Cl： 1.43-3.31; P = 0.0002）. These results suggest an increased risk of the GSTPI variant genotype （lle/Val ＋ Val/Val） for developing male factor infertility. Our findings also underrate the significance of the effect of GSTM1 and/or GSTT1 （especially the former） in modulating the risk of male infertility in males from Sichuan, southwest China.

关键词： genetic polymorphism glutathione S-transferase idiopathic infertility male factor

Light field super-resolution using complementary-view feature attention

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Computational Visual Media 2023年第4期9卷 843-858页

作者： Wei Zhang Wei ke Da Yang Hao Sheng Zhang xiong Faculty of Applied Sciences Macao Polytechnic UniversityMacao SAR 999078China State key Laboratory of Software Development Environment School of Computer Science and EngineeringBeihang UniversityBeijing 100191Chinaand Beihang Hangzhou Innovation Institute YuhangXixi Octagon CityYuhang DistrictHangzhou 310023China

Light field(LF)cameras record multiple perspectives by a sparse sampling of real scenes,and these perspectives provide complementary information.This information is beneficial to LF super-resolution(LFSR).Compared with traditional single-image super-resolution,LF can exploit parallax structure and perspective correlation among different LF views.Furthermore,the performance of existing methods are limited as they fail to deeply explore the complementary information across LF views.In this paper,we propose a novel network,called the light field complementary-view feature attention network(LF-CFANet),to improve LFSR by dynamically learning the complementary information in LF views.Specifically,we design a residual complementary-view spatial and channel attention module(RCSCAM)to effectively interact with complementary information between complementary views.Moreover,RCSCAM captures the relationships between different channels,and it is able to generate informative features for reconstructing LF images while ignoring redundant information.Then,a maximum-difference information supplementary branch(MDISB)is used to supplement information from the maximum-difference angular positions based on the geometric structure of LF images.This branch also can guide the process of reconstruction.Experimental results on both synthetic and real-world datasets demonstrate the superiority of our method.The proposed LF-CFANet has a more advanced reconstruction performance that displays faithful details with higher SR accuracy than state-of-the-art methods.

关键词： light field(LF) super-resolution(SR) attention

Medium Access Control： A Physical Layer Network- Coded Approach

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China Communications 2014年第A02期11卷 1-11页

作者： ZHANG Yu XIONG Ke DU Liping School of Computer and Communication Engineering University of Science and Technology Beijing Beijing 100083 P. R. China School of Computer and Information Technology Beijing Jiaotong University Beijing 100044 P. R. China National Mobile Communications Research Laboratory Southeast University Nanjing 210018 P. R. China

This paper investigates the medium access control (MAC) stratifies for communication systems. Since the signals are naturally superposed in public medium, we introduce physical layer network coding into MAC system and propose the physical layer network coded MAC (PNC-MAC) to utilize the collisions occurring in the MAC process. The implicit expressions of the throughput and average delay of the system operated with the new algorithm are derived in an iterative way. To show the performance of the algorithm, we compare the throughput and average delay induced by the new algorithm with current schemes via simulations. The results show that when operated with our proposed PNC-MAC, MAC system can achieve a larger throughput while the frames bear shorter average delay. Moreover, in many users case, the throughput increases slightly while the average delay ascends drastically.

关键词：介质访问控制编码方法物理层层网络 MAC系统平均延时通信系统吞吐量

Effects of dark matter on shadows and rings of Brane-World black holes illuminated by various accretions

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 27-43页

作者： Xiao-xiong Zeng ke-Jian He Guo-Ping Li State key Laboratory of Mountain Bridge and Tunnel Engineering Chongqing Jiaotong UniversityChongqing 400074China Department of Mechanics Chongqing Jiaotong UniversityChongqing 400074China College of Physics Chongqing UniversityChongqing 401331China Physics and Space College China West Normal UniversityNanchong 637000China

In this study, by taking the accretions into account, the observed shadows and rings cast by the Brane-World black hole were numerically investigated when the observer was located at the cosmological horizon. The results showed that the radius rpof the photon sphere increased with the cosmological parameter α and dark matter parameter β, while the impact parameter bpdecreased with α and increased with β. For thin disk accretion, the total observed intensity is mainly composed of direct emission.Simultaneously, the lensing ring and photon ring have only small and negligible contributions, respectively. We also found that shadows and rings exhibit different and exciting features when the disk is located at different positions. For static and infalling spherical accretions, it is evident that the size of shadows is always the same for both accretions. This implies that shadows are only related to space-time geometry in this case. The luminosity of the shadow and photon sphere is closely associated with the Doppler effect and the emissivity per unit volume j(νe). In addition, the influence of dark matter and cosmological constant on the observed intensity of shadows and rings is carefully emphasized throughout this paper. Finally, we obtained the burring images of shadows and rings using the nominal resolution of the event horizon telescope. We also studied the upper limits of the X-clod dark matter parameter β using the data of the shadow of M87.

关键词： dark matter the accretion black hole shadow lensing and photon rings

Towards green for relay in InterPlaNetary Internet based on differential game model

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Science China(Information Sciences) 2014年第4期57卷 65-73页

作者： LIN FuHong LIU Qian ZHOU XianWei XIONG Ke School of Computer and Communication Engineering University of Science and Technology Beijing School of Computer and Information Technology Beijing Jiaotong University State key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University

InterPlaNetary Internet(IPN)plays a very important role in the exploitation of space.However,the relays in IPN are suffered from high symbol error,limited storage space,and limited available energy.To analyze the performance of the relay in IPN,in this article,we build a differential game model,where the controller is transmitting rate,and the goal is to maximize the payoff according to the symbol error rate,the storage space and the available energy in the system.By such a design,the green relays can be achieved for IPNs,which could prolong the live of the relays.Since the model is not easy to discuss,we analyze it using the Bellman theorem and then get some formulas on the trace of the optimal transmitting rate.Finally,extensive simulation results are presented to demonstrate the performance of our proposed model,which shows that by using our derived optimal transmitting rate trace,the relay’s payoff can be maximized.

关键词： IPN differential game symbol error limited storage space energy efficiency

Chronic intermittent hypoxia increases ROS/HIF-1a related oxidative stress and worsen bleomycin-induced pulmonary fibrosis in adult male C57BL/6J mice

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Chronic intermittent hypoxia increases ROS/HIF-1a related ox...