Opportunistic Wireless Internet Access in Vehicular Environments Using Enhanced WAVE Devices

Yunpeng Zang,Erik Weiss,Lothar Stibor,Bernhard Walke,Hui Chen,Xi Cheng 보안공학연구지원센터 2008 International Journal of Hybrid Information Techno Vol.1 No.2

The emerging Car-to-Car communication (C2C) technology, known as Wireless Access in Vehicular Environments (WAVE), enables vehicles on the roadway to communicate with each other and with the roadside infrastructure. In addition to safety-relevant services, drivers may also need Internet access through C2C communications for infotainment services and car maintenance services, as specified in MobilitY and CollAboRative Work in European Vehicle Emergency NeTworks (MYCAREVENT) project. In this article we propose solutions for providing on-board Internet access service to automotive users through C2C communications. The proposed solutions make use of roadside infrastructure and the novel MYCAREVENT Vehicular Communication Gateway (VCG) device. A management scheme is developed for the opportunistic wireless links between On-Board Units (OBUs) and Road-Side Units (RSUs), as well as between OBUs and VCGs in vehicular communications. Furthermore, we invent a novel MAC queue architecture addressing the drawback of the current WAVE MAC protocol in supporting unicast traffic in highly dynamic vehicular environments. At the end, stochastic simulation results are presented to prove the concepts and validate the proposed solutions.

Variable speed sliding mode control of magnetic suspension linear synchronous motor based on feedback linearization

Yunpeng Sun,Yipeng Lan,Xiaolei Shi,Zelai Xu,Cheng Lei 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.11

In the high-speed and high-precision magnetic suspension linear synchronous motor, the non-linear coupling between armature current, suspension height and horizontal velocity, as well as the uncertain factors such as load disturbance, which will have many adverse effects on the control system. To solve these problems, this paper uses a feedbacklinearized control method. Through coordinate transformation and state feedback, the nonlinear model of motor affine is decoupled and linearized into three independent linear subsystems of straight axis current subsystem, horizontal speed subsystem and suspension height subsystem. In order to reduce the dependence of feedback linearization control on linear motor mathematical model and improve the robustness of servo system, so as to realize decoupling control of magnetic suspension linear synchronous motor, a variable speed reaching law sliding mode controller is designed on the basis of linearization model. Simulation and experimental results show that the dynamic and static performance of the system is enhanced significantly by using the proposed control strategy.

Energy-Efficient Secure Multiuser Scheduling in Energy Harvesting Untrusted Relay Networks

Dechuan Chen,Yunpeng Cheng,Xiangdong Wang,Weiwei Yang,Jianwei Hu,Yueming Cai 한국통신학회 2019 Journal of communications and networks Vol.21 No.4

In this paper, we investigate opportunistic secure multiuserscheduling in energy harvesting untrusted relay networks,where an energy-constrained amplify-and-forward (AF) relay harvestsenergy from the received radio frequency signal via usingthe power splitting protocol. To exploit the potential advantages(e.g., multiuser diversity and direct links) for secrecy improvement,we examine three opportunistic user scheduling schemes,i.e., optimal scheduling scheme, maximum scheduling scheme, andminimum scheduling scheme. Specifically, the optimal schedulingscheme performs user selection by maximizing the ratio betweenthe signal-to-noise-ratio (SNR) at the destination and the correspondingSNR at the untrusted relay. The maximum schedulingscheme is conventional user selection that maximizes the channelgain of the direct links. For the minimum scheduling scheme, wetry to reduce the overheard information at the untrusted relay byselecting the user with the lowest channel gain of the relay links. For these three schemes, we comprehensively examine the achievablesecrecy performance including probability of positive secrecyrate, secrecy outage probability (SOP), asymptotic SOP, secrecythroughput (ST), as well as secure energy efficiency (SEE) to helpfacilitate an energy-efficient secure transmission design. Simulationresults demonstrate that the maximum scheduling scheme outperformsthe minimum scheduling scheme in terms of SOP at relativelylow SNRs and target secrecy rates.

Increasing Secrecy Capacity via Joint Design of Cooperative Beamforming and Jamming

( Xinrong Guan ),( Yueming Cai ),( Weiwei Yang ),( Yunpeng Cheng ),( Junquan Hu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.4

In this paper, we propose a hybrid cooperative scheme to improve the secrecy rate for a cooperative network in presence of multiple relays. Each relay node transmits the mixed signal consisting of weighted source signal and intentional noise. The problem of power allocation, the joint design of beamforming and jamming weights are investigated, and an iterative scheme is proposed. It is demonstrated by the numerical results that the proposed hybrid scheme further improves secrecy rate, as compared to traditional cooperative schemes.

IL-6-miR-210 Suppresses Regulatory T Cell Function and Promotes Atrial Fibrosis by Targeting Foxp3

Chen, YingWei,Chang, GuoDong,Chen, XiaoJie,Li, YunPeng,Li, HaiYu,Cheng, Dong,Tang, Yi,Sang, HaiQiang Korean Society for Molecular and Cellular Biology 2020 Molecules and cells Vol.43 No.5

The aim of this study was to explore the role of IL-6-miR-210 in the regulation of Tregs function and atrial fibrosis in atrial fibrillation (AF). The levels of interleukin (IL)-6 and IL-10 in AF patients were detected by using ELISA. Proportions of Treg cells were detected by fluorescence activated cell sorting analysis in AF patients. The expression of Foxp3, α-SMA, collagen I and collagen III were determined by western blot. The atrial mechanocytes were authenticated by vimentin immunostaining. The expression of miR-210 was performed by quantitative real-time polymerase chain reaction (qRT-PCR). TargetScan was used to predict potential targets of miR-210. The cardiomyocyte transverse sections in AF model group were observed by H&E staining. The myocardial filaments were observed by masson staining. The level of IL-6 was highly increased while the level of IL-10 (Tregs) was significantly decreased in AF patients as compared to normal control subjects, and IL-6 suppressed Tregs function and promoted the expression of α-SMA, collagen I and collagen III. Furthermore, miR-210 regulated Tregs function by targeting Foxp3, and IL-6 promoted expression of miR-210 via regulating hypoxia inducible factor-1α (HIF-1α). IL-6-miR-210 suppresses regulatory T cell function and promotes atrial fibrosis by targeting Foxp3.

Two-Dimensional POMDP-Based Opportunistic Spectrum Access in Time-Varying Environment with Fading Channels

Wang, Yumeng,Xu, Yuhua,Shen, Liang,Xu, Chenglong,Cheng, Yunpeng The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.2

In this research, we study the problem of opportunistic spectrum access (OSA) in a time-varying environment with fading channels, where the channel state is characterized by both channel quality and the occupancy of primary users (PUs). First, a finite-state Markov channel model is introduced to represent a fading channel. Second, by probing channel quality and exploring the activities of PUs jointly, a two-dimensional partially observable Markov decision process framework is proposed for OSA. In addition, a greedy strategy is designed, where a secondary user selects a channel that has the best-expected data transmission rate to maximize the instantaneous reward in the current slot. Compared with the optimal strategy that considers future reward, the greedy strategy brings low complexity and relatively ideal performance. Meanwhile, the spectrum sensing error that causes the collision between a PU and a secondary user (SU) is also discussed. Furthermore, we analyze the multiuser situation in which the proposed single-user strategy is adopted by every SU compared with the previous one. By observing the simulation results, the proposed strategy attains a larger throughput than the previous works under various parameter configurations.

Two-Dimensional POMDP-Based Opportunistic Spectrum Access in Time-Varying Environment with Fading Channels

Yumeng Wang,Yuhua Xu,Liang Shen,Chenglong Xu,Yunpeng Cheng 한국통신학회 2014 Journal of communications and networks Vol.16 No.2

In this research, we study the problem of opportunisticspectrum access (OSA) in a time-varying environment with fadingchannels, where the channel state is characterized by bothchannel quality and the occupancy of primary users (PUs). First,a finite-state Markov channel model is introduced to represent afading channel. Second, by probing channel quality and exploringthe activities of PUs jointly, a two-dimensional partially observableMarkov decision process framework is proposed for OSA. In addition,a greedy strategy is designed, where a secondary user selects achannel that has the best-expected data transmission rate to maximizethe instantaneous reward in the current slot. Compared withthe optimal strategy that considers future reward, the greedy strategybrings low complexity and relatively ideal performance. Meanwhile,the spectrum sensing error that causes the collision betweena PU and a secondary user (SU) is also discussed. Furthermore,we analyze the multiuser situation in which the proposed singleuserstrategy is adopted by every SU compared with the previousone. By observing the simulation results, the proposed strategy attainsa larger throughput than the previous works under variousparameter configurations.