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With the development of the Internet, the speed of knowledge update is getting faster and faster, and the Internet is full of various knowledge data. For knowledge management systems, the knowledge classification function is very important. The main task of this paper is to learn the mapping relationship between text content and text category according to the given text content and text category, so as to get a classification model. Finally, use this classification model to process the text of the unknown classification, and judge or predict the category of the unknown text.

The reflectivity spectra of 808 nm/980 nm double band mirror(DBM) are characterized in the paper.According to the structure of the DBM,the thermal model of Optically Pumped Vertical-External-Cavity Surface Emitting Semiconductor Lasers(OPS-VECSELs) with DBM is constructed and the distribution of thermal load in the VECSEL wafer is presented.The thermal characterization of OPS-VECSELs with DBM is analyzed in detail by finite element method.The results indicate that VECSEL wafer with DBM has better thermal properties and poorer thermal performance than with DBM when they have the same reflectivity(R=99.96%).So VECSEL wafer with DBM is more suitable for making high power semiconductor laser than with DBM.The theoretical analysis results will be provided as theory reference for VECSEL wafer structure optimization and experimental.

The resolution of traditional far-field imaging system is generally restricted by half of wavelength of incident light due to the diffraction limit. The reason is that evanescent waves carrying subwavelength information cannot propagate in the far-field and make no contribution to the imaging. To realize the far-field super-resolution imaging, the imaging system should be able to collect both propagation and evanescent waves. Many ideas were presented to provide feasible alternatives but with narrow frequency band. In this paper, a wideband metalens is proposed to realize far-field super-resolution based on stereometamaterials. A typical model of stereometamaterials is studied, which consist of a stack of two identical spiral resonators in each cell, with various twist angles. For each case, there are two observable resonances (-and +), obviously. The phenomenon can be explained as the plasmon hybridization between the two resonators due to their close proximity. The case with a twist angle of 90 is chosen as the basic cell to constitute the stereo-metalens (S-ML). The last S-ML can work in a frequency range from 1.06 to 1.53 GHz, which is much wider than the planar-metalens. Simulations of near-and far-field spectra are conducted to validate the conversion between evanescent waves and propagation waves. Then with the help of antennas in the far-field to receive the information, sub-wavelength image can be reconstructed. The simulations in frequency-and time-domain are performed to verify the super-resolution characteristics of the S-ML. In frequency-domain, an imaging simulation of L-shaped extended target is combined with multiple signal classification imaging method. The resolution defined by full width at half maximum is 19 mm, corresponding to /12. For comparison, a similar simulation without the S-ML is performed, indicating a resolution of 1.5. It shows the ability of the S-ML to enhance the imaging resolution. In time-domain, by using time reversal technique, the spatial super-resolution characteristic of the S-ML is validated. Compared with the planar-metalens, the S-ML has good spatial super-resolution characteristic. All results show that the S-ML has a good potential application in imaging.

This paper investigates the effect of Dresselhaus spin-orbit coupling on the spin-transport properties of ferromagnet/insulator/semiconductor/insulator/ferromagnet double-barrier structures. The influence of the thickness of the insulator between the ferromagnet and the semiconductor on the polarization is also considered. The obtained results indicate that (i) the polarization can be enhanced by reducing the insulator layers at zero temperature, and (ii) the tunnelling magnetoresistance inversion can be illustrated by the influence of the Dresselhaus spin–orbit coupling effect in the double-barrier structure. Due to the Dresselhaus spin–orbit coupling effect, the tunnelling magnetoresistance inversion occurs when the energy of a localized state in the barrier matches the Fermi energy EF of the ferromagnetic electrodes.

The relationships and the features of integration between Enterprise Process Monitoring and Controlling System (EPMCS) and Enterprise Process Related Applications (EPRA) were analyzed. An integration architecture centered on EPMCS was presented, in which there were four layers to connect from EPMCS to EPRA:EPMCS, application integration layer, transport layer and EPRA, and there were four layers used to etstablish integration: presentation layer, function layer, data layer and system layer. The frameworks to connect EPMCS and EPRA were designed, that Enterprise-Independent Model (EIM), Enterprise-Specific Model (ESM) and meta-model to describe these two models were defined. The method to integrate data based on XML was designed to exchange data from EPMCS to EPRA according to the mapping between EIM and ESM. The approches are suitable for integrating EPMCS and systems in Product Data Management (PDM), project management and enterprise business management.

For far-field imaging applications, the imaging resolution of conventional lenses is limited by the diffraction limit because of the exponential decay of high spatial frequency waves. The key to realizing the subwavelength imaging lies in the collection of evanescent informations in far-field region. However, the collection of evanescent waves is not the only thing we need to do. The relation between target position and far-field information is also very important. In this paper, a far-field time reversal subwavelength imaging system is constructed with the help of an evanescent-to-propagating conversion plate, i. e., a grating plate. The designed grating plate is able to convert evanescent waves into propagating waves through the modulation in space-spectrum domain. In order to clearly understand the conversion, a focusing experiment is conducted with two sources and five time reversal mirror antennas. By recording the amplitudes of the time reversal signals in the two source positions, we can see that the amplitude of the refocusing signal at the original source position is much larger than that of the other signal. Through numerical simulation and experiment, the conversion of evanescent wave into propagative wave is proved finally. Then, according to the self-conjugation property of time reversal, the result of self-conjugation for channel response in complex environment is nearly the same as an impulse function. The image of source target can be reconstructed without exact prior knowledge of the expression of the spatial channel response. In order to exemplify the super resolution property of our designed system, experiments with simulation data and experimental data are executed with and without our designed grating plate, respectively. For imaging applications, we first record the forward signals received by the time reversal mirror antennas, and then record the refocusing field distribution on the imaging plane to obtain the image of the target. In the reconstruction process, another thing we need to notice is that the original sources should be removed. This is because in a real imaging application, we cannot know the exact position of target inadvance. The imaging results show that the resolution of our imaging system has overcome the diffraction limit. Compared with the imaging resolution of the imaging system without the grating plate, the imaging resolution of the system with our designed grating plate is improved obviously. Since this kind of method overcomes the intrinsical diffraction limit by transmitting evanescent information to far-field region in a way of converting them into propagative waves. This kind of method offers us a promising alternative to microwave far-field subwavelength imaging applications.

Detecting copy images of a query image in large scale image collections is a very important task for many applications, such as copyright violations detection and copy image filtering in the results of image retrieval. In this paper, a novel method is proposed in which each image is represented as a set of local keypoints. The local keypoint is characterized by a compact fingerprint to minimize the effect of color changing. This keypoint descriptor is more compact than the feature vector descriptor. Hamming distance is used to measure the similarity of two fingerprints. To retrieve a fingerprint quickly in one large scale fingerprint collection, a fast retrieval method is adapted to construct sorted tables of the fingerprints by grouping the bits of fingerprint. This retrieval method has low complexity. The experimental results validate the effectiveness of the proposed algorithms.

The method based on ACT-R cognitive framework involved in bend movement is presented in this paper, which defines perception-action modules, memory modules and core unit of decision-making cycle which includes visual and tactile perception of traffic conditions rules. The paper introduces nine components of state to describe bend movement. Bend movement is divided into normal rational driving behavior and non-rational driving behavior which can be affected by drivers' fatigue, characters, etc. This paper also analyzes the impact of actions and requirements of action generation. Utility function is used to evaluate drivers' actions on the basis of driver's perception expressed by the actions under the new state. The validity of these models is tested by a number of simulations, recommended parameter values are given in this paper to illustrate the effectiveness of decision-making behavior based on ACT-R model.

This paper starts from the methods of caculation and decompostion of Gini coefficient, in which we take urban pupulation as an increasing function of education, and analyzing the composition effect and compression effect of education on income inequality. We make a simulation of this model, using OLS and quantile regression method, and find that there is an inverse-U shape relationship between income inequality and education. We reckon that one cannot take education as a main cause of income disparity and income inequality, just because the educational returns of higher income group are larger than that of the lower income group. Our analysis focuses that, even if the income disparity between urban and rural keep expanding in the future, the improving of educational level will accelerate the transion of population which finaly reduce the urban-rural income inequality. In a word, the improving of educational level will finaly reduce the urban-rural income disparity and income inequality.

There are a lot of dead zone in many controlled systems. Different from other non-linear characteristics, dead zone has its special non-linear characteristics, which needs compensation measures in order to achieve the desired effect. By analysis of dead-zone non-linear characteristics, multi-joint robot models, and control simulation of two-joint robots, this paper is aimed to design fuzzy compensator and adaptive control system, which has good controlling effect.

This paper analyzes characteristics of network education, introduces the importance of education with network resources and the autonomous learning ability required in network education. It further proposes the main problems of students in network educational environment and provides relevant solutions and strategies.

This paper introduces a mathematical model for chunk parsing of Chinese sentence. Automatic identification of Chinese chunk is implemented by using BP network. Based on BP network, some new research methods and experiments on the input features are proposed and performed in this paper. The experimental results show that the full use of the known information can improve the accuracy of Chinese chunk identification.

RFID systems, owning to their low cost and conveniences in identifying, have been applied in many fields. But the features of RFID system and the constraints of RFID devices may bring about various security problems. In this paper, firstly we analyze Hash-Lock protocol and its patulous protocols. Based on the analysis, we propose an improved security solution of RFID system. Analyzed from the security and the privacy, this solution can prevent tracking, eavesdropping and inimical attacking. It has high security. But it still has the problem of big computational load.

UHF RFID system is becoming more widespread. In order to meet application need, by analyzing the characteristic of UHF RFID reader in ISO18000-6B standard, technology target for UHF RFID reader is made, the design solution of UHF reader is presented and the selection for key parts is finished. This UHF reader based on ARM9 MPU has merits such as fast read-write speed (single tag 64 bit/6 ms), high recognition rate and long recognition distance (>6m). It can meet application requirements in practical application. It can meet application need.

Vanadium dioxide (VO2) thin film have been fabricated on the ZnO-doped Al conductive glass (AZO) substrates by DC magnetron sputtering and after thermal annealing. Effect of different annealing temperature and time olunation on the VO2/AZO composite films has been studied, then the structure, components and optical-electrical properties of the composite films are tested and analyzed by suitable instruments. Results show that the AZO film deposited on the conductive glass substrate dose not change the preferred orientation growth of the VO2 thin film, but its surface morphology characteristics are changed. Compared with those fabricated on ordinary glass substrates by the same processes and conditions, the phase transition temperature of the VO2/AZO composite film is decreased by about 25 ℃, and the width of thermal hysteresis is narrowed to about 6 ℃. Before and after phase transition, the visible light transmittance remains higher than 50%, and the infrared transmittances at a wavelength of 1500nm are 55% and 21% respectively. Furthermore, the resistivity rangeability is also up to three orders of magnitude before and after phase transition. In conclusion, the VO2/AZO composite films are easy to be fabricated and have a high degree of stability, smooth ness and compact surface morphology, thus they may be used to make new photoelectric devices

A new general network model for two complex networks with time-varying delay coupling is presented. Then we investigate its synchronization phenomena. The two complex networks of the model differ in dynamic nodes, the number of nodes and the coupling connections. By using adaptive controllers, a synchronization criterion is derived. Numerical examples are given to demonstrate the effectiveness of the obtained synchronization criterion. This study may widen the application range of synchronization, such as in chaotic secure communication.