41 research outputs found
Conceal an entrance by means of superscatterer
By using the novel property of the rectangular superscatterer, we propose a
design which can conceal an entrance from electromagnetic wave detection. Such
a superscatterer is realized by coating a negative index material shell on a
perfect electrical conductor rectangle cylinder. The results are numerically
confirmed by full-wave simulations both in the far-field and near-field.Comment: 10 pages, 4 figure
Morphological and Biological Variation of the Self Progeny of \u3ci\u3ePennisetum purpureum\u3c/i\u3e
Effect of NaCl Concentration on Embryogenic Callus Growth and Plant Regeneration of \u3cem\u3ePennisetum Purpureum\u3c/em\u3e Schumach (Napier Grass) \u3cem\u3ein Vitro\u3c/em\u3e
Effect of Adding Lemon Grass to Dairy Cow Diets on Milk Quality and Blood Oxidation Resistance
Low frequency elastic wave propagation in 2D locally resonant phononic crystal with asymmetric resonator
The resonance modes and the related effects to the transmission of elastic
waves in a two dimensional phononic crystal formed by periodic arrangements of
a two blocks unit cell in one direction are studied. The unit cell consists of
two asymmetric elliptic cylinders coated with silicon rubber and embedded in a
rigid matrix. The modes are obtained by the semi-analytic method in the least
square collocation scheme and confirmed by the finite element method
simulations. Two resonance modes, corresponding to the vibration of the
cylinder along the long and short axes, give rise to resonance reflections of
elastic waves. One mode in between the two modes, related to the opposite
vibration of the two cylinders in the unit cell in the direction along the
layer, results in the total transmission of elastic waves due to zero effective
mass density at the frequency. The resonance frequency of this new mode changes
continuously with the orientation angle of the elliptic resonator.Comment: 17 pages, 7 figure
Technique of Plant Regeneration from Immature Inflorescence of \u3cem\u3ePennisetum Purpureum in Vitro\u3c/em\u3e
Somatic Embryogenesis and Plant Regeneration from Immature Inflorescences of \u3cem\u3ePennisetum purpureum\u3c/em\u3e Schumach (Napier Grass)
Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation
By focusing on the issue of rolling element bearing (REB) performance degradation assessment (PDA), a solution based on variational mode decomposition (VMD) and Gath-Geva clustering time series segmentation (GGCTSS) has been proposed. VMD is a new decomposition method. Since it is different from the recursive decomposition method, for example, empirical mode decomposition (EMD), local mean decomposition (LMD), and local characteristic-scale decomposition (LCD), VMD needs a priori parameters. In this paper, we will propose a method to optimize the parameters in VMD, namely, the number of decomposition modes and moderate bandwidth constraint, based on genetic algorithm. Executing VMD with the acquired parameters, the BLIMFs are obtained. By taking the envelope of the BLIMFs, the sensitive BLIMFs are selected. And then we take the amplitude of the defect frequency (ADF) as a degradative feature. To get the performance degradation assessment, we are going to use the method called Gath-Geva clustering time series segmentation. Afterwards, the method is carried out by two pieces of run-to-failure data. The results indicate that the extracted feature could depict the process of degradation precisely
H∞ Filter Design for Networked Control Systems: A Markovian Jump System Approach
This paper puts forward a method to design the H∞ filter for networked control systems (NCSs) with time delay and data packet loss. Based on the properties of Markovian jump system, the packet loss is treated as a constant probability independent and identically distributed Bernoulli random process. Thus, the stochastic stability condition can be acquired for the filtering error system, which meets an H∞ performance index level γ. It is shown that, by introducing a special structure of the relaxation matrix, a linear representation of the filter meeting an H∞ performance index level for NCSs with time delay and packet loss can be obtained, which uses linear matrix inequalities (LMIs). Finally, numerical simulation examples demonstrate the effectiveness of the proposed method