Function projective synchronization of complex networks with asymmetric coupling via adaptive and pinning feedback control

The problem on function projective synchronization (FPS) is investigated for complex networks via hybrid control. In contrast to existing works, the asymmetric coupling matrix was considered. Based on adaptive and pinning feedback control methods, new FPS criteria are proposed. Finally, three examples are provided to illustrate the effectiveness of the proposed methods.     

Grey relational analysis model for dynamic hybrid multiple attribute decision making

In this paper, the dynamic hybrid multiple attribute decision making problems, in which the decision information, provided by decision makers at different periods, is expressed in real numbers, interval numbers or linguistic labels (linguistic labels can be described by triangular fuzzy numbers), respectively, are investigated. The method first utilizes three different GRA (grey relational analysis (real-valued GRA, interval-valued GRA and fuzzy-valued GRA) to calculate the individual grey relational degree of each alternative to the positive and negative ideal alternatives based on the decision information expressed in real numbers, interval numbers and linguistic labels, respectively, provided by each decision maker at each period, and then adopt the concept of fuzzy membership grade and clustering to aggregate the grey relational degree of all the evaluated periods. Finally, an illustrative example is given to verify the developed approach and to demonstrate its practicality and effectiveness.     

无线传感网络中基于自动学习机的数据传输策略

尽管多径路由能够提高数据包传输成功率,但是其增加参与数据传输的节点数,提升了网络能耗。为此,提出基于自动学习机的单径路由(Single Path-based Learning Automation Routing,SPLAR)。设计SPLAR路由的主旨在于以最少能耗实现数据包传递率的最大化和端到端传输时延的最小化。通过自动学习机构建每个节点的动作集,并依据环境学习更新每个动作的概率。再选择具有最高概率的动作传输数据。仿真结果表明,提出的SPLAR路由在数据包传递率和端到端传输时延具有较好的性能。     

High-stability conducting polymer-based conformal electrodes for bio-/iono-electronics

Compared to conventional rigid electronics, polymer-based soft electronics conformal to organisms of irregular shapes have emerged as the next-generation devices, especially benefiting long-term bio-interface interactions that avoid mechanical mismatch and consequent adverse immune responses. Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has become a promising candidate for building soft conductors/electrodes due to its good conductance, tunable mechanical stiffness, good biocompatibility and facile fabrication into various structures. However, their high instability towards alkaline, reductants and applied voltage has not yet been fully addressed, which inevitably leads to deteriorated performance in complex physiological environments or weather conditions (e.g., humidity). Such intolerances are rooted in unstable electronic/molecular structures of PEDOT caused by de-doping. Besides the low electrical stability, PEDOT:PSS films also exhibit an impaired overall conductance due to its phase separation into PSS-rich and PEDOT-rich domains. Herein, a general and effective coating strategy is proposed, based on a mechanism of simultaneous molecular rejection and electron conjugation, to improve the stability and boost the conductance. Specifically, a reduced-graphene-oxide (rGO) thin layer can not only protect PEDOT: PSS from being de-doped by alkali, bio-reductants and applied voltage through molecular rejection, to maintain its conductivity and ensure stable functions, but also further boost the overall conductance through a bridging effect with its large conjugated domain. This strategy is compatible with various material fabrication techniques, including blade-coating, dip-coating and extrusion-based printing techniques, enabling the fabrication of conductors/electrodes with different structures. Finally, the advantages of excellent stability and high conformability of the composite films as soft conductors have been demonstrated through practical applications in tissue stimulation, electrophysiological recording and proprioceptive hydrogel skins, exhibiting great promise in bio/iono-electronics and human–machine interactions.     

Effect of off-axis angle on mesoscale deformation and failure behavior of plain-woven C/SiC composites with digital image correlation

In this study, the deformation response and failure behavior of a plain-woven C/SiC composite were investigated under on-axis and off-axis tensile loading. Digital image correlation (DIC) was utilized to characterize the full-field deformation and mesoscale strain distribution. The test results indicate a strong influence of the woven architecture on the mechanical properties and strain distribution, and the materials exhibit failure modes dependent on the loading directions or off-axis angles: the fracture positions of different layers are the same under off-axial load, while for on-axil loading, the fracture positions of different layers do not affect each other. SEM results provide direct evidence that the width of the off-axis specimen has a great influence on the mechanical properties. The reduction of the modulus and strength of off-axis specimen, is not only due to the off-axis loading, but also due to the reduction of effective bearing area or effective bearing fiber.     

Through thickness property variations in friction stir welded AA6061 joint fatigued in very high cycle fatigue regime

Ultrasonic fatigue tests were performed on friction stir welded AA6061 joint to investigate very high cycle fatigue (VHCF) behaviors. As a result, almost all the fatigue cracks are initiated from local plastic slip markings around the boundary between thermo-mechanically affected zone and heat affected zone. The fatigue strength decreases from the top to root of the welded joint, owing to the variation of plastic deformation history and temperature distribution through the thickness. In fractography, the fatigue crack initiation site is surrounded by a semicircular flat zone, of which the formation in VHCF regime accounts for more than 98% of the total fatigue life.     

Further improved stability criteria for uncertain T–S fuzzy systems with time-varying delay by (m,N)-delay-partitioning approach

This paper mainly focuses on the robust stability criteria for uncertain T–S fuzzy systems with time-varying delay by (m,N)-delay-partitioning approach. A modified augmented LKF is established by partitioning the delay in all integral terms. Via taking into account of (i) the relationship between each subinterval and time-varying delay and (ii) the independent upper bounds of the delay derivative in the various delay intervals, some new results on tighter bounding inequalities such as Peng-Park׳s integral inequality and Free-Matrix-based integral inequality are introduced to effectively reduce the enlargement in bounding the derivative of LKF as much as possible, therefore, significant less conservative results can be expected in terms of e_s and LMIs, which can be solved efficiently with the Matlab LMI toolbox. Furthermore, it is worth mentioning that, when the delay-partitioning number m is fixed, the conservatism is gradually reduced with the increase of another delay-partitioning number N, but without increasing any computing burden. Finally, two numerical examples are included to show that the proposed method is less conservative than existing ones.     

受限空间火灾探测数据融合算法研究

为了实现对受限空间火灾发生情况多传感器自动探测信号处理,建立了基于CO浓度、烟气颗粒浓度、红外视频图像等多传感器探测的火灾探测数据融合分析系统.在受限空间内搭建基于多传感器火灾探测的数据融合分析实验平台.根据火灾红外视频图像的燃烧区域面积及圆形度等特征参数介绍了红外图像识别算法.在三种火灾探测方式特征参数的基础上提出了...     

水成膜泡沫在航空煤油表面的封闭性效果

采用不同环境温度、不同混合比对水成膜泡沫在燃油液面的覆盖开展了封闭性验证实验,通过测定可燃蒸气的浓度及检测时间分析了水成膜泡沫的封闭性随环境温度、混合比的变化规律.实验结果表明:水成膜泡沫的封闭性随环境温度的升高而变差,对于3％的水成膜泡沫,环境温度为40℃时的初次检测可燃蒸气的时间比80℃时的检测时间延长149 s;...