Advanced Materials Research Vols. 225-226

Abstract: Aim at the problem of supervised learning needing much labeled data for training, this paper proposes a new method based on Semi-Supervised learning. Firstly, to construct a classifier of certain accuracy, small-scale training data was used.Secondly, with the self-expanding idea, we applied the method of information entropy to select some new instances of higher credibility from candidate instances, which were to be predicted by the classifier. Finally, with the expansion of training data, training classifier re-iteratively, classification performance tended to be stable iteration termination, which achieved the entity relation extraction of tourism field by semi-supervised learning. The experiments result show that the new classifier which applies information entropy to iteratively expand training data to be trained makes the precision rate increase by 7% and the F-score increase by 15%.

Abstract: At present, virtual reality technology is research hot spot in computer science. Campus roaming system is one application aspect of virtual reality technology. It provides a new means for digital campus. This paper gives a detail discussion for the design plan for three-dimensional virtual campus system with the aim to provide a practical avenue for the establishment of virtual campus roaming system.

Abstract: A number of existing centrifugal fans’ aerodynamic sketches and dimensionless characteristics are investigated and evaluated by means of statistical method. Based on the statistical data, the optimum curve of centrifugal fans is replenished and amended. The paper also puts forward the relation curve between exit width of blade and diametral quotient, and discusses its application in fans’ design and calculation.

Abstract: The paper develops a special CAD system for the centrifugal fan. The system can realize the automatic selection,aerodynamic design calculation,main parts parameterized drawing and other functions of the fan. It avoids the repetition of the manual labor and enhances the working efficiency and the cartography quality. On the base of the research on the selecting method and regularity of the main parameters of a large number of existing high performance centrifugal fans, the paper provides a new method, which determines the main geometric parameters of centrifugal impeller.

Abstract: Based on the cross-sectional data and from the shareholding structure, this paper analyzes the current status of ownership structure of Chinese listed companies, with ROE as the measure of the efficiency of corporate governance. It uses the regression analysis method to study the equity structure effects of listed corporate governance empirically. The conclude points out the factors of imperfect governance structure and the resolutions of that, as well as the policy recommendations of optimizing the ownership structure of listed companies and improving the governance structure.

Abstract: To investigate the relationship of surface electromyogram (sEMG) and handgrip force, a measurement system was developed. Ten healthy subjects were required to perform a series of static contraction trials by maintaining the force level with maximal voluntary contraction (MVC), 75%MVC, 50%MVC and 25%MVC respectively. Then they sustained MVC as long as possible until fatigue. The handgrip force and sEMG on the forearm muscles were recorded. Root mean square (RMS), mean power frequency (MPF) and median frequency (MF) of the sEMG were calculated with LabVIEW. The results show that RMS increased with force level during voluntary contraction, while MPF and MF shift to lower frequency during fatigue condition. These findings suggested that the designed system can be used to study forearm function.

Abstract: Based on Nd:YAG laser, tunable diode laser, electro-optic amplitude modulator and the difference frequency generator, a servo scanning laser source is designed, and the principle of trace gas concentration measurement model is introduced as well, which can realize the gas concentration measurement in the band of mid-infrared and far-infrared. Based on the theory of electromagnetic field, mutual coupling equation about laser transmission in nonlinear crystal and the optical frequency conversion characteristics are analyzed theoretically. As a result, in the range of far-field, electric field intensity of coupled wave increases approximatively exponentially,then tends to be stable.

Abstract: When the observation station and the satellite or the spaceship are coplanar, the earth can be approximated into an uniform sphere. By applying the sine rule of plane geometry, the orbit arc length can be calculated which each observation station can measure. Numbers of observation stations should at least be established can be calculated by using the ratio method. When the earth’s self-rotation is taken into account, we can calculate the fewest numbers of observation stations by calculating the area of spherical surface that each station can observe and combining the division of regular hexagon of a football. In the end, the article analyzes the related material of ShenZhou V and the period of time of each station.

Abstract: In our vision location system, error is inevitable. Image quantization errors play an important role in computer vision field. Quantization errors are the primary sources that affect the precision of pose estimation and they are inherent and unavoidable. It is important to analysis on the effect of this error on compute process. In this paper, Robustness problem argumentation in vision location is presented in detail. Then we introduce image quantization error. Robustness mathematical model for vision location is set up at last.

Abstract: This paper analyzes electrochemical corrosion consequence that the orbit traffic stray current acts on buried metal. According to regularities of distribution of orbit traffic stray current, it analyzes the rationality that CAN bus is used in orbit traffic stray current monitoring, and designed the online monitoring system of stray current based on CAN. The system was verified through the laboratory simulation.