The purpose of this paper is to exploit compressive sensing (CS) method in dealing with electrocardiography (ECG) and electroencephalography (EEG) signals at a high compression ratio. In order to get sparse data of ECG and EEG signals before being compressed,a combined scheme was presented by using wavelet transform and iterative threshold method; then,compressive sensing is executed to make the data compressed. After doing compressive sensing,Bayesian compressive sensing (BCS) is used to reconstruct the original signals. The simulation results show that compressive sensing is an effective method to make data compressed for ECG and EEG signals with high compression ratio and good quality of reconstruction. Furthermore,it shows that the proposed scheme has good denoising effects.
We devise three sorts of doped left-handed materials (DLHMs) by introducing inductors and capacitors into the traditional left-handed material (LHM) as heterogeneous elements. Some new properties are presented through finite- difference time-domain (FDTD) simulations. On the one hand, the resonance in the traditional LHM is weakened and the original pass band is narrowed by introducing inductors. On the other hand, the original pass band of the LHM can be shifted and a new pass band can be generated by introducing capacitors. When capacitors and inductors are introduced simultaneously, the resonance of traditional LHM is somewhat weakened and the number of original pass bands as well as its bandwidth can be changed.
The response of field electron emission of cadmium sulfide (CdS) nanowires (NWs) to visible light has been investigated.It is found that,upon light illumination,the turn-on voltage drops,emission current increases obviously,and the Fowler-Nordheim behavior deviates from a straight line.A process of field emission coupled with semiconducting properties of CdS NWs is proposed.Photon-excited electron transition from the valence band to the conductance band of CdS nanowires increases the quantity of emitting electrons,and the photoemission decreases the effective work function of CdS emitters,which largely enhances the field emission performance.The response of field emission of CdS NWs to light illumination suggests an approach for tuning field emission of semiconductor emitters.
