Advanced Materials Research Vol. 658

Abstract: The performance of a high-field asymmetric waveform ion mobility spectrometry (FAIMS) detector is directly related to the quality of the asymmetric waveform generator. In this paper, we propose a design scheme of a multi-mode asymmetric waveform generator based on the half-bridge architecture, using a direct digital synthesizer (DDS) method to produce a frequency adjustable square wave pulse and half-sine pulse signal. An isolation circuit was combined with a drive circuit through a TLP250 which is a MOSFET driver chip with photoelectric isolation. The frequency of the proposed waveform generator can be easily controlled.

Abstract: Based on measured data of Wuxinzhai tunnel in expressway of Shanyin to Pinglu, mathematical methods were used to make regressing analysis of measured date on crown settlement and periphery convergence. According to the time-effect of soil mass excavation in New Austrian Tunneling Method, the relations between rock deformation and time during the tunnel construction was analyzed. The results of analysis could provide an theoretical basis for modifying design and construction , and also could offer an example for similar projects in this area.

Abstract: In this paper, a new fuzzy inference method for fault diagnosis expert system is proposed. Firstly, fault antecedents were processed by lexical analysis including removing redundant vocabulary and word segmentation. Secondly, for the purpose of improving the precision of the inference, we used the membership degree, and defined the confidence level of antecedent and the confidence level of conclusion and the closeness degree of the knowledge base rules. Finally we gave the reasoning processes and algorithms.

Abstract: This paper introduces a novel preprocessing method for palm vein recognition system. Preprocessing is a key step of palm vein recognition system. In the step of preprocessing, the vein vessel under the palm skin is expected to be exactly extracted. In our method, a certain video sequence in which all the palm vein is included is captured by self-designed palm vein capture device. In the step of data collection, user's palm is restrained and he or she is asked to keep his or her palm still. Spectral density method is used to find the stable certain-frequency signal in the captured video sequence. The stable certain-frequency signal is expected to represent the vein vessel in the palm. Experimental results show the effectiveness of the proposed method.

Abstract: This paper mainly studies on the classification of pathological voice from normal voice based on the sustained vowel /a/. Firstly, the original 18 acoustic features are extracted. Then on the basis of the extracted parameters, this paper recognizes the pathological voice using AD Tree. During the classification stage, the cross-validation of features is also as references in the process. This method is validated with a sound database provided by the Massachusetts Eye and Ear Infirmary (MEEI). After the 10 fold cross-validation, comparing with 7 other kinds of classifiers, the experimental results show that AD Tree can get the highest recognition rate of 95.2%. The method in this paper shows that all the extracted parameters are reasonable in the following recognition process and AD tree is a good recognition way in pathological voice research.

Abstract: In this paper, a method of being modified 2-D DOA estimation is presented. By reconstructing covariance matrix of the received array data, the correlativity of the incident signals is recreased, and mis-division between signal subspace and noise subspace is controlled, therefore the number of estimated signals would be equal to the number of actual incident signals. This method has good performance not only for DOA estimation of the correlation signals, but for DOA estimation of the non-correlation signals. In addition the computational complexity will not increase obviously. The simulation tests verify the validity of the presented algorithm.

Abstract: This paper discusses the 3-level charge pumping method in planar-type Silicon-Oxide-High-k-Oxid e-Silicon (SOHOS) and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) devices to find out the reason for degradation of data retention properties. In the CP thechnique, a pulse is applied to the gate of the MOSFET which alternately fills the traps withe electrons and holes, thereby causing a recombination current Icp to flow in the substrate. A 3-level charge pumping method may be used to determine not only interface trap densities but also capture cross sections as a function of trap energy. By applying this method, SOHOS device found to have a higher interface trap density than SONOS device. Therefore, degradation of data retention characteristics is attributed to the many interface trap sites.

Abstract: With the development of the information age, the demands for computer software have become increasingly complex. Increasing scale, with the development of enterprises, and the reorganization of the work process, which make the requirements change become increasingly frequent. Formal theoretical foundation based on rCOS, leads to integration and refinement for Volere requirements process model. According to the RUP process, a trusted Simple Volere Requirement Model has been constructed to solve the requirements change as a very effective way.