Applied Mechanics and Materials Vols. 347-350

Abstract: This paper proposed an improved method on the basis of the extended proportional guidance law. The method solved the weak observability problem of system sate in guided missile attacking maneuvering target. It is simple in form and easy for engineering implementation. This paper set up relative motion model and the observability theory indexes. The improved propotional guidance law is simulated using the MATLAB language. The simulation results show that the method is reasonable, effective and improving the observability.

Abstract: Recently, with the rapid development of Chinese flower market, the precision irrigation problem is generally concerned. This paper mainly introduces the basic principles of the automatic irrigation system, and realizes the automatic control of the irrigation volume in irrigation system by utilizing the self-learning characteristics of BP neural network model and the powerful data processing ability of the matlab software.

Abstract: Wireless sensor networks are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. However, deploying wireless sensor networks on the sea poses many challenges. To deal with the problems, we proposed a hybrid wireless sensor networks deployed on the sea which combines the advantages of wireless sensor networks (WSNs) and Underwater Acoustic Sensor Networks (UWA-SNs ) together. In this paper, we first introduced the structure of the double-head sensor node, and then discussed the applications of the hybrid networks, such as ocean monitoring, test bed and intrusion detection. We also present the analysis of deployment of the hybrid sensor networks.

Abstract: In magnetic heading measurement of quadrotor, it is necessary to compensate the magnetic deviation of the electronic magnetic compass. For the flight characteristics of quadrotor, a method using sampling data when the aircraft is in the air to achieve automatic compensation of the deviation has been proposed. Using elliptical hypothesis method one can only compensate deviation for quadrotor flying in horizontal plane by collecting the magnetic sensor data in different directions. When the quadrotor flying in any attitudes, using ellipsoid hypothesis method can obtain parameters used by magnetic deviation compensation. Using these parameters, the pitch and roll angles of quadrotor, the magnetic deviation could be compensated. Experimental results show that this method works well and has a good real time performance. The measurement error of heading angle could be less than 1 °.

Abstract: Localization is used in location-aware applications such as navigation, autonomous robotic movement, and asset tracking to position a moving object on a coordinate system. In this paper, we present a localization model based on the irregular quadrilateral in wireless sensor networks. Firstly, a quadrilateral-positioning unit is presented. It may prevent the unknown node falls into the external of positioning unit. Lastly, we use RSSI value to find the nearest reference sample nodes from unknown node, compared with the SBL localization algorithm, our algorithm improve the positioning accuracy. Theoretical analysis and simulation results show that the algorithm in wireless sensor networks and other location-based applications have a good effect.

Abstract: In order to accurately analyze the result, which comes from quantitative and qualitative detection based on gamma energy spectrum of NaI(T1) detector, peak boundary has become one of the main factors which influence the spectrum analysis. By implementing some common boundary determining algorithms in the Matlab such as simple comparison method, derivative method, symmetry zero-area method, the full width method and gaussian function fitting method, as well as comparing effectiveness among those algorithm, priority of those boundary algorithms is evaluated. At the same time, because the boundary determining algorithm based on traditional gaussian fitting is not ideal, the new boundary determining algorithm based on the least squares fitting of gaussian function with weighting factor is proposed. The practice verifies that this method is stability and can obtain preferable convergence result in boundary determining of unimodal or combination peaks.

Abstract: The Chinese Solar Radio Heliograph (CSRH) is a new generation radio heliograph would produce more than 4 terabytes data every day. As a aperture synthesis telescope, CSRH is facing the challenge of processing and storing such a vast data. Pipeline system is the key issue of data automatical processing for CSRH. In this study, to push the development of CSRH, we present a framework of high performance data processing pipeline system for saving and processing real-time observation data. The related techniques of pipeline software are presented in detail including raw data acquisition, UVFITS file, data calibration, parallel computing and data publication. The pipeline has been deployed and has played an important role for the development of CSRH.

Abstract: With the rapidly deteriorating of ecological environment and depletion of resources, construction investment of eco-materials industry is gradually increasing , so the investment risk assessment has become a hot research problem at present. In this paper, a new investment risk assessment system for eco-materials industry is presented, which combines rough set approach and support vector machine (SVM). It is different from traditional statistical methods. We can get reduced information table by rough set, which implies that the number of index and qualitative variables is reduced with no information loss by rough set approach. And then, this reduced information is used to develop classification rules, and SVM is trained to infer appropriate parameters. The result of the positive research indicated that this system is very valid for investment risk assessment of eco-materials industry and it will have a good application prospect in this area.

Abstract: This paper develops an ultrasound-based surgical navigation system for percutaneous renal intervention. The proposed system integrates preoperative magnetic resonance (MR) planning with intraoperative ultrasonography (US) slices, where the MR imagery is registered to the calibrated US data. The interventional punctures can be performed under a visualized guidance interface. We describe this navigation system in details and evaluate the navigated intervention via a phantom model.

Abstract: The issue of angle estimation for multiple-input multiple-output (MIMO) radar is studied and an algorithm for the estimation based on compressive sensing with multiple snapshots is proposed. The dimension of received signal is reduced to make the computation burden lower, and then the noise sensitivity is reduced by the eigenvalue decomposition (EVD) of the covariance matrix of the reduced-dimensional signal. Finally the signal subspace obtained from the eigenvectors is realigned to apply the orthogonal matching pursuit (OMP) for angle estimation. The angle estimation performance of the proposed algorithm is better than that of estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm, and reduced-dimension Capon. Furthermore, the proposed algorithm works well for coherent targets, and requires no knowledge of the noise. The complexity analysis and simulation results verify the effectiveness of the algorithm.