Applied Mechanics and Materials Vols. 321-324

Abstract: The reflectivity, loss function, refractive index, extinction coefficient and dielectric function of the LaNi₅ and LaNi_4.5Sn_0.5 intermetallic compounds are investigated through the plane-wave pseudo-potential method based on the density functional theory. The effects of Sn impurity are discussed and some interesting features are found in the low frequency region. Some important optical properties such as static dielectric constant and static refractive index are obtained. The equation [n (0)]²=ε₁(0) is satisfied according to our calculation, which indicates that our results are correct and reasonable. Nevertheless, the calculated results need to be testified in the future due to the lack of experimental data.

Abstract: Density-functional theory has been used to calculate the energetically global-minimum geometries and electronic states of Ag_nH₂S (n=2, 4, 6) clusters. The lowest-energy structures of Ag₂, Ag₄, Ag₆, Ag₂H₂S, Ag₄H₂S and Ag₆H₂S clusters were obtained, respectively. The calculation results show that the lowest-energy structures of Ag₂, Ag₄ and Ag₆ clusters are planar geometries. The binding energies of Ag_n(n=2, 4, 6) clusters are gradually increasing in our calculations. Compare the infrared spectrum peaks of Ag₄ cluster with that of Ag₆ cluster, which show that the peaks shift to shortwave. After adsorption, we found that the peaks shift to shortwave by comparison.

Abstract: Multi-block gray statistics local dimming algorithm is proposed to automatically control the brightness of the backlight for reducing energy consumption and enhancing the image quality. The large blocks are used to determine the value of backlight matrix and small blocks are to determine the image block brightness. With the use of BMA (Blur-mask approach) to blur the backlight brightness matrix and compensate LCD control signal, local dimming function is realized.The simulation results show that: for pictures, the average backlight power consumption is decreased markedly by 19.9% and the contrast ratio is increased by 53%.

Abstract: In order to further understand the transmission characteristics of UV-light signal, this paper, based on the algorithmic model of Monte Carlo method of UV-light non-line-of-sight transmission, conducts the simulation analysis of the obstacle impact on UV-light signal transmission characteristics in the atmosphere. The results show that due to the presence of obstacle, the blind region of detection appears; this blind region is related to the distance of the obstacle, as well as to transmission elevation angle, receiving elevation angle and obstacle height of obstacle. The obstacle exerts a slight influence on energy intensity, but just its height changes the range of blind region detection. The transmission elevation angle and the receiving elevation angle, in case of the presence or absence of the obstacle, have two energy distribution peaks which change to some extent, and the energy attenuation is more significant in case of the absence of the obstacle.

Abstract: This paper proposes a level and cluster based routing approach for a wireless sensor network. Nodes in the network are divided into several levels according to their hops to sink node. Every sensor node has a level number. Using level information, a sensor node can send messages to a sink node in a more efficient way, and a sink node can easily locate other sensor nodes. To make network more balanced, the paper introduces a cluster method, which splits nodes in the same level into different clusters, and chooses a cluster head for every cluster, to switch nodes in the cluster to work in turn. Unlike all other cluster routing methods, a cluster head node takes schedule jobs of sensor nodes in the cluster according to their energy left, instead of sensing. The paper also presents several algorithms for constructing a wireless sensor network, querying and scheduling. The simulation experiment shows that the scalability of our method is approximately linear.

Abstract: According to the characteristics of GWSN, a Multi-Agent cooperation system structure of GWSN is put forward based on the complexity and changeableness of water area and biologic growth. In this structure, the Agent is divided into mobile Agent and static Agent. Static Agent is responsible for collecting data, and mobile Agent is responsible for move between clusters. Each cluster cooperation agents are responsible for data transmission and the data fusion process is divided into four levels. It manages greenhouse wireless measurement and control system by distributed agents’ information timely interaction and cooperation.

Abstract: An embedded attitude estimation system is developed for the autonomous flight of Quad-Rotor UAVs. The system hardware is composed of a DSP processor and low-cost MEMS sensors including a 3-axis gyroscope and a 3-axis accelerometer. A Complementary Filter fused the advantages of the gyroscope and accelerometer is designed and embedded on the DSP processor to estimate the real-time attitude. Ground testing experiments show that the system could meet the accuracy and robustness requirements for the Quad-Rotor UAVs attitude estimation.

Abstract: This study issues the improvement of the parameters of manufacturing on the flexible SAW device. The better piezoelectric characteristics of ZnO film will be obtained. The Sol-Gel method is used to prepare the ZnO solution and deposits ZnO film by spin coating process. X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to get the crystalline property. The results reveal that ZnO film possesses better crystalline property in 400RPM of spin speed. The piezoelectric intensity of (002) direction is 1566.67 (a.u.) and atomic morphology of ZnO film are exhibited by SEM image. This better ZnO film will enhance the wave propagation of surface acoustic wave (SAW) device. It can also expand the application of SAW device.

Abstract: Monitoring system can be performed both offline and online, and this research carries out the design of long-distance monitoring system for moving system. GPS module is used as system input containing position information of monitored system. This information is processed by the system and is sent by GSM module. On the receiver side, the data are compiled for monitoring system movement. The system is implemented using µC Cortex-M4 by applying Event Driven method. This method is applied for saving resource. The result shows good accuracy level which is measured based on monitoring with system position in the field

Abstract: Mutual information (MI) has been widely used in multisensor image matching, but it may lead to mismatch among images with messy background. However, additional prior information can be of great help in improving the matching performance. In this paper, a robust Bayesian estimated mutual information, named as BMI, for multisensor image matching is proposed. This method has been implemented by utilizing the gradient prior information, in which the prior is estimate by the kernel density estimate (KDE) method, and the likelihood is modeled according to the distance of orientations. To further improve the robustness, we restrict the matching within the regions where the corresponding pixels of template image are salient enough. Experiments on several groups of multisensor images show that the proposed method outperforms the standard MI in robustness and accuracy and is similar with Pluims method. However, our computation is far more cost saving.