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Security-aware Signal Packing Algorithm for CAN-based Automotive Cyber-physical Systems

IEEE/CAA Journal of Automatica Sinica 2015年第4期2卷 422-430页

作者： Yong Xie Liangjiao Liu Renfa Li Jianqiang Hu Yong Han Xin Peng Key Laboratory for Application Technology of Internet of Things of Fujian Educational Bureau Xiamen University of Technology Key Laboratory of Embedded and Networking Computing of Hunan Province Hunan University Key Laboratory on Complex Systems Optimization & Controlling of Hunan High Education Institutions Hunan Institute of Science and Technology

Network and software integration pose severe challenges in cyber-security for controller area network (CAN)-based automotive cyber-physical system (ACPS), therefore we employ message authentication code (MAC) to defend CAN against masquerade attack, but the consequent bandwidth overhead makes it a necessity to find the tradeoff among security, real-time and bandwidth utilization for signal packing problem (SPP) of CAN. A mixed-security signal model is firstly proposed to formally describe the properties and requirements on security and real-time for signals, and then a mixed-integer linear programming (MILP) formulation of SPP security-aware signal packing (SASP) is implemented to solve the tradeoff problem, where the bandwidth utilization is improved and the requirements in both security and real-time are met. Experiments based on both society of automotive engineers (SAE) standard signal set and simulated signal set showed the effectiveness of SASP by comparing with the state-of-the-art algorithm. © 2014 Chinese Association of Automation.

关键词： Algorithms Bandwidth Communication channels (information theory) Control system synthesis Embedded systems Integer programming

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Porosity Resolved Elasticity,Thermal Conductivity and Stability of Foamed Materials

Porosity Resolved Elasticity,Thermal Conductivity and Stabil...

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第十四届全国物理力学学术会议

作者：钟沅周兆锋 NI Cang-Hao Key Laboratory of Key Film Materials & Application for Equipment(Hunan Province) School of Materials Science and EngineeringXiangtan University Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and EngineeringXiangtan University

Porous material is a fascinating kind of substance that demonstrates unusually tunable functionalities such as the melting point(T),Young modulus(Y) and thermal conductivity(k) that remain no longer constant but change with the size(L) and concentration of the *** we present an approach to unify these seemingly irrelevant properties using a three-component media premise from the perspective of atomic undercoordination induced local bond *** between theory predictions and experimental measurements of these properties for multiple foamed specimens confirms the validity of the approach that is essential to the understanding the abnormal performance of the foamed substance.

关键词： foamed material porosity effect melting point Young modulus thermal conductivity

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Research for the Working Method of Live Replacing the L-type Insulator String on ±800kV DC Transmission Lines

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： Jinliang Li Zhigang Wang Dongyun Lei Miao Yang Zengming Xia Yun Xiang Yu Yan Zhiguo Liu State Grid Hunan Electric Power Company Live Working Center Changsha 410100 China Hunan Province Key Laboratory of Intelligent live working Technology and Equipment (Robot) Changsha 410100 China

It would be hard to be repaired in the case of a power outage if the ±800kV ultra high voltage DC (UHVDC) transmission line was put into operation, so live working is the guarantee for its security and stability. Insulator strings of duplex L-type are widely used in UHVDC small angle towers. In the meantime, the tower structure and the insulator strings' arrangement type is different than the V-type. In order to ensure the security and stability of the transmission line, this paper presents a method of live replacing the duplex L-type insulators based on the actual parameter of the UHVDC L tower type and develops apparatus as a complementary supporting by mechanics analysis. In order to ensure the safety of working staff, the safe distance and combined gap of the hanging basket method are checked. Safety precautions are also proposed in the paper by the calculation of body surface field strength of the persons doing live working in the finite element method. It is shown by the field application that the live working task of replacing the L-type insulator strings can be accomplished successfully by the method put forward in this paper, which provides reference for the following live working on the UHV transmission line.

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Study on Control of Two Axis Linkage of Live-working robot for Power Transmission Lines

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： Yu Yan Dehua Zou Xiaqing Liu Jinliang Li Zhanfan Zhou State Grid Hunan Electric Power Company Live Working Center Changsha 410100 China Hunan Province Key Laboratory of Intelligent live working Technology and Equipment (Robot) Changsha 410100 China

A two axis linkage dynamic control method for joint space of a live-working robot for power transmission lines is presented in order to solve the problem of that the working efficiency of the live-working robot is low in single joint serial connection working. This paper established a global dynamical equation during obstacle-crossing through the Newton-Euler approach, providing the basis for establishing any two-axis linkage dynamic equation; analyzed and determined joints of the robot capable of two axis linkage, presenting a group of common dynamical equations for two axis linkage joints; and designed a PD control method with a gravity model. Simulation and experimental results show that the two axis linkage method is feasible and capable of increasing working efficiency of the robot.

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Development of Live-working robot for Power Transmission Lines

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： Yu Yan Xiaqing Liu Chengxian Ren Jinliang Li Hui Li State Grid Hunan Electric Power Company Live Working Center Changsha 410100 China Hunan Province Key Laboratory of Intelligent live working Technology and Equipment (Robot) Changsha 410100 China

Dream-I, the first reconfigurable live-working robot for power transmission lines successfully developed in China, has the functions of autonomous walking on lines and accurately positioning. This paper firstly described operation task and object of the robot; then designed a general platform, an insulator replacement end and a drainage plate bolt fastening end of the robot, presented a control system of the robot, and performed simulation analysis on operation plan of the robot; and finally completed electrical field withstand voltage tests in a high voltage hall as well as online test and trial on actual lines. Experimental results show that by replacing ends of manipulators, the robot can fulfill operation tasks of live replacement of suspension insulators and live drainage plate bolt fastening.

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Walking Posture Control of Transmission Line Single Arm Inspection robot

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： Yu Yan Xiaqing Liu Jinliang Li Yuexiong Ou State Grid Hunan Electric Power Company Live Working Center Changsha 410100 China Hunan Province Key Laboratory of Intelligent live working Technology and Equipment (Robot) Changsha 410100 China

To control the walking posture according to transmission line single arm inspection robot, the robot is divided into normal walking and climbing walking two state, and gives the definition, then based on the state space method of state variable feedback and PD control method is used to control the two states, two kinds of control method of simulation by using Matlab, in the end, the two control methods proposed is validated in the actual circuit structures. The results show that, the proposed control method is rapid and effective, and can meet the needs of practical application.

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Research on Walking Wheel Slippage Control of Live Inspection robot

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IOP Conference Series: Materials Science and Engineering 2017年第1期224卷

作者： Yu Yan Xiaqing Liu Hao Guo Jinliang Li Lanlan Liu State Grid Hunan Electric Power Company Live Working Center Changsha 410100 China Hunan Province Key Laboratory of Intelligent live working Technology and Equipment (Robot) Changsha 410100 China

To solve the problem of walking wheel slippage of a live inspection robot during walking or climbing, this paper analyzes the climbing capacity of the robot with a statics method, designs a pressing wheel mechanism, and presents a method of indirectly identifying walking wheel slippage by reading speed of the pressing wheel due to the fact that the linear speed of the pressing wheel and the walking wheel at the contract point is the same; and finds that the slippage state can not be controlled through accurate mathematical models after identifying the slippage state, whereas slippage can be controlled with fuzzy control. The experiment results indicate that due to design of the pressing wheel mechanism, friction force of the walking wheel is increased, and the climbing capability of the robot is improved. Within the range of climbing capability of the robot, gradient is the key factor that has influence on slippage of robot, and slippage can be effectively eliminated through the fuzzy control method proposed in this paper.

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Effects of Growth Stress in Finite-Deformation Thermally Grown Oxide on Failure Mechanism of Thermal Barrier Coatings

Effects of Growth Stress in Finite-Deformation Thermally Gro...

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第十四届全国物理力学学术会议

作者：申强杨丽周益春 WEI Y G ZHU W Key Laboratory of Key Film Materials & Application for Equipment(Hunan Province) School of Materials Science and EngineeringXiangtan University Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and EngineeringXiangtan University State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences

Thermally grown oxide(TGO),besides bringing extra mismatch between layers in thermal barrier coatings(TBCs),induces volumetric expansion and local large deformation in constrained interface,which results in huge growth stress and then causes the spallation of ***,characterization on the dynamic growth of oxide and stress evolution during oxidation are desirable,but still intractable,especially considering local finite *** the present research,the effects of growth stress evolution in the TGO on the failure mechanism of TBCs are investigated through developing both finite deformation mechanics-oxidation growth model and corresponding finite element *** demonstrate that the TGO growth rate decreases as oxidation time increases and is uneven in different positions,which is consistent with the experimental *** maximum tensile stress and compressive stress are situated at the peak and valley regions of bond coating layer,***,the stress distribution in top coating is opposite to that of bond *** implies that the thermal stress in the TGO layer dominates the failure of the *** with small deformation analysis,the maximum stress value in finite deformation description is closer to the experimental result,and it is more suitable to evaluate the growth stress induced by the growth of TGO layer.

关键词： thermal barrier coatings finite deformation growth stress thermally grown oxide growth finite element method

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Simultaneous extraction of DNA and RNA from Escherichia coli BL 21 based on silica-coated magnetic nanoparticles

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Science China Chemistry 2015年第11期58卷 1774-1778页

作者： Jiuhai Wang Zeeshan Ali Nianyue Wang Wenbiao Liang Hongna Liu Fu Li Haowen Yang Lei He Libo Nie Nongyue He Zhiyang Li State Key Laboratory of Bioelectronics School of Biological Science and Medical Engineering Southeast University Clinical Laboratory the Second Hospital of Nanjing Jiangsu Province Blood Center Economical Forest Cultivation and Utilization of 2011 Collaborative Innovation Center in Hunan Province Hunan Key Laboratory of Green Packaging and Application of Biological Nanotechnology Hunan University of Technology Department of Laboratory Medicine the Second Affiliated Hospital of Nanjing Medical University

The extraction of nucleic acid is recognized as one of the most essential steps in molecular biology for initiating other downstream applications such as sequencing, amplification, hybridization, and cloning. Many commercial kits and methods are currently available that allow the extraction of only one type of nucleic acids-DNA or RNA. However, in parallel clinical detection of several diseases, a method for simultaneous extraction of both DNA and RNA from the same source is needed in such cases. In this study, a method for simultaneous extraction of DNA and RNA from bacteria based on magnetic nanoparticles(MNPs) was described. Lysis buffers were prepared to help the nucleic acid released and adsorbed to MNPs. Then, two washing buffers were used to remove the contamination of proteins and carbohydrates. The nucleic acids were finally eluted by Deoxyribonuclease(DNase) and Ribonucleases(RNase) free water. Different factors which might affect the purification of the nucleic acid were investigated, and the quantity and quality parameters of the nucleic acid were also recorded. The DNA and RNA extracted from bacteria were then respectively subjected to polymerase chain reaction(PCR) and reverse transcription PCR(RT-PCR) to further confirm its quality. The results indicated that our method can be successfully used to simultaneously extract DNA and RNA from bacteria.

关键词： nucleic acids simultaneous extraction magnetic nanoparticles （MNPs） bacteria

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Spallation of Thermal Barrier Coatings with Real Thermally Grown Oxide Microscopy under Thermal Stress

Spallation of Thermal Barrier Coatings with Real Thermally G...

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第十四届全国物理力学学术会议

作者：杨丽 ZHANG Z B 周益春 ZHU W WEI Y G WU R T Key Laboratory of Key Film Materials & Application for Equipment(Hunan Province) School of Materials Science and EngineeringXiangtan University Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education School of Materials Science and EngineeringXiangtan University State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences National Institute for Materials Science

Experimental observations display that there exist two types of cracks induced by thermally grown oxide(TGO) in electron beam physical vapor deposition(EB-PVD) thermal barrier coatings(TBCs),which will lead to the coating *** to now,the failure mechanism is not *** the present research,based on the analysis for the experimental observations of the previous researches,a model for crack propagation and failure in TBCs is established,which covers the constitutive equation and the crack propagation *** on the model,a finite element method is developed,which is specifically for the failure of TBCs with real TGO morphology and with an image processing *** the finite element method the coating failure mechanism under thermal mismatch stress is *** analysis and discussion show that the horizontal crack tends to propagate through the top coat layer toward the interface during the cooling stage,while the interface crack initiates at the points located in the middle region and then propagates in two side directions simultaneously,and mode II fracture plays a dominant role in the whole crack propagation ***,two failure mechanisms of the TC/TGO interface at EB-PVD TBCs are proposed in this paper.

关键词： thermal barrier coatings real thermally grown oxide morphology thermal stress distribution crack propagation failure mechanism

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