Robust Adaptive Multi-Switching Synchronization of Multiple Different Orders Unknown Chaotic Systems

Multi-switching synchronization(MSS) of multiple different orders unknown chaotic(UC)systems confines hacking in the digital transmission process. Similarly, the suppression of undesirable chattering increases synchronization performance. This paper proposes a new robust synchronization control(RASC) technique and discusses the MSS of multiple different orders UC systems. This controller accomplishes(i) quick convergence,(ii) reduces the transient oscillations, and(iii) the rate of convergence decreases in the vicinity of the origin that causes the suppression of chattering. Analysis based on the Lyapunov direct method assures this convergence behavior with any positive values of the feedback gains. This work also provides parameters updated law that estimates the true values of unknown parameters. Numerical examples of five UC systems different orders are simulated. The computer based graphical results validate the efficiency and performance of the proposed RASC technique and the synchronization strategy when compare to peer works. In the simulation, the proposed synchronization strategy successfully recovers an encrypted received image on a communication channel.The article suggests some future research problems to extend the use of the proposed work.     

Bioactivity analysis of the Ta (V) doped SiO2–CaO–Na2O–P2O5 ceramics prepared by solid state sintering method

The main objective of the study was to control the degradation rate of material at a higher degradation rate improving the chemical stability of the material. Ta is known to have good chemical resistance, biocompatibility and show no adverse biological response. In the present study, SiO2–Na2O–CaO–P2O5 bioceramics with different Ta2O5 contents was prepared by solid state sintering method at 1000 °C. The as-sintered ceramics were subjected to immersion studies in stimulated body fluid (SBF) for 21 days under static condition and characterized by XRD, FTIR, SEM, and AAS. The findings of the research indicate that the addition of Ta2O5 controlled degradability, and all samples showed sufficient bioactivity.     

Improved hybrid position/force controller design of a flexible robot manipulator using a sliding observer

An improved hybrid position/force controller design of a flexible robot manipulator is presented using a sliding observer. The friction between the end effector and the environment is considered and compensated. For systematic reasons the controller is designed taking into consideration the rigid link subsystems and the flexible joints. The proposed control system satisfies the stability of the two subsystems and copes with the uncertainty of robot dynamics. A sliding observer is designed to estimate the time derivative of the torque applied as input to the rigid part of the robot. For the stability of the observer, it is assumed that the uncertainty of the observed system is bounded. A MRAC algorithm is used for the estimation of the friction forces at the contact point between the end effector and the environment. Finally simulation and experimental results are given, to demonstrate the effectiveness of the proposed controller.     

双参数量子群U_(r,s)(D_∞)（英文）

研究了D∞型双参数量子代数Ur,s(g)=lim Ur,s(SO2n).首先给出了双参数量子代数Ur,s(g)的定义,然后n→∞证明Ur,s(g)是一个Hopf代数,接下来找到双参数量子代数Ur,s(g)的两个子代数B和B′,使得Ur,s(g)可以由其Drinfeld对来实现.此外,Ur,s(g)有一个三角分解Ur,s(g)≌u-uou+.     

Long-term potentiation of NMDA receptor-mediated synaptic transmission in the hippocampus.

Neurotransmission at most excitatory synapses in the brain operates through two types of glutamate receptor termed alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and N-methyl-D-aspartate (NMDA) receptors; these mediate the fast and slow components of excitatory postsynaptic potentials respectively. Activation of NMDA receptors can also lead to a long-lasting modification in synaptic efficiency at glutamatergic synapses; this is exemplified in the CA1 region of the hippocampus, where NMDA receptors mediate the induction of long-term potentiation (LTP). It is believed that in this region LTP is maintained by a specific increase in the AMPA receptor-mediated component of synaptic transmission. We now report, however, that a pharmacologically isolated NMDA receptor-mediated synaptic response can undergo robust, synapse-specific LTP. This finding has implications for neuropathologies such as epilepsy and neurodegeneration, in which excessive NMDA receptor activation has been implicated. It adds fundamentally to theories of synaptic plasticity because NMDA receptor activation may, in addition to causing increased synaptic efficiency, directly alter the plasticity of synapses.     

节能型嵌入式系统的系统级设计技术

现在对于低功耗的嵌入式计算系统的需求持续上升。信息技术的发展使得集成电路单位面积上集成的晶体管越来越多，这就必然导致单位面积上的功耗越来越大，局部过热会让晶体管处于不稳定状态，因此，低功耗技术的研究意义十分重大。本书主要讨论节能型嵌入式系统的有效自动设计技术的开发和验证，重点介绍了嵌入式系统的系统级同步综合技术，包括动态电压调度处理器技术。这种技术在性能和功耗之间权衡，使得系统低功耗高性能。