Applied Mechanics and Materials Vols. 571-572

Abstract: This paper investigates the application of the adaptive feedback control method in the chaotic system and Single-state Adaptive Feedback Controller. We divide the adaptive feedback controller into several items, each of which has only one component of the system states as feedback input into each dimension of the system. With the introduction of single-state controller, the scale of control inputs can be flexibly adjusted, the additional loading reduced, better convergence effect obtained and the application field of adaptive feedback control methods further extended in stable control analysis of chaotic systems. An example is also given to illustrate the validity of our result.

Abstract: Aiming to realistic requirement to reusability and composability of radar countermeasure test simulation and modeling, the ontology construction method has been proposed by analyzing the influence of ontology in terms of knowledge management and formal description. The design of ontology-based component library and the solutions of composable modeling have been discussed, and the effectiveness has been validated by examples that the methods can satisfy the requirements of model reusability and simulation compos-ability in the field of radar countermeasure test simulation and modeling.

Abstract: This paper presents a new kind of light emitting diode(LED) secondary light distribution lens which adopts the type of Fresnel lens surface. The research purpose of this paper is to improve the LED heat dissipation efficiency of the secondary light distribution lens and the light efficiency, so as to prolong the service life of the LED. In this paper, we use the numerical method for solving the partial differential equation to establish a freeform surface lens which could produce uniform illumination, then the innovative method of combine the Fresnel lens structure with freeform surface lens was proposed. The design of freeform surface Fresnel lens allows dramatically cut the thickness of the lens (as well as the weight and volume) , it can solve the problem of difficulty in heat dissipation. By comparing the ray tracing simulation results of original freeform surface lens and freeform surface Fresnel lens in optical simulation software, experiments show that the latter not only shows the same degree of illumination uniformity, but also greatly reduced the thickness of the lens.

Abstract: For senior citizens and people with disabilities and other special groups, it is inconvenient for them to use the ordinary desk lamp. This essay presents a design scheme of intelligent desk lamp based on infrared detector. Pyroelectric infrared sensor can detect infrared radiation of human, which can be used as the automatic switch to solve the limitation of the manual switch for these special groups. Intelligent desk lamp can meet these crowds on the specialized requirements of everyday lighting lamp according the characteristic. Compared with the traditional household table lamp, this design has the distinct characteristics of intelligence, pertinence and reliability.

Abstract: Intelligent insecticidal lamp with LED is more efficient than ordinary insecticidal lamp. It used solar battery as the power supply, used high voltage power grid as hunting tools, used power LED which was controlled by singlechip as trapping tools for killing more insects. It could work at the night in spring or summer by data acquisition of clock chip and sensors and could automatically shut down in the rainy day or foggy day.

Abstract: Long-External Cavity Laser (L-ECL) is a kind of new and promising type laser because of its dynamic single mode performance. In this paper, firstly, the theory model of L-ECL is discussed; Secondly, the influence of coupling coefficient on the threshold gain of L-ECL is studied based on equivalent external cavity theory; Thirdly, utilizing the theory of equivalent cavity length, combined rate equations, the high frequency response characteristic of L-ECL is analyzed; Lastly, optical spectrums of L-ECL on different grating peak reflectivity are obtained by experiment.

Abstract: New micromachining techniques now provide the opportunity to fabricate vacuum electron devices with dimensions suitable for operation in the terahertz region of the electromagnetic spectrum. In this paper, results of theoretical and numerical simulation studies of a MW-class, large diameter terahertz backward wave oscillator are presented. A novel full electromagnetic particle-in-cell simulation tool UNIPIC is also introduced. With this method, we studied the device at the frequency of 0.14 THz. It is found that the steady-state, single-frequency operation in this oversized situation could be realized by the property of surface wave near the upper cutoff area.

Abstract: Euler-Lagrange (Euler-Lagrange, EL) mathematical model was established according to the topology of TNPC (T-type Neutral Point Clamped) PV grid-connected inverter. Based on the mathematical models and passivity-based control theory, the approach called injecting damping was adopted to design the passivity-based controller of the inverter. The passivity-based controller can decouple d-q axis current at AC side of the grid and achieve unity power factor, the total harmonic distortion of grid-connected current is low, and the passivity-based controller also make the inverter have good dynamic and static performances. Simulation results show that the designed passive controller of TNPC PV grid-connected inverter is feasible.

Abstract: Developing trusted QoS architecture is important for wireless multimedia sensor networks considering various applications with different QoS requirements. First, the diverse multimedia traffic were analyzed and classified based on application requirements, service model, and multimedia coding method in wireless multimedia sensor networks. And the QoS requirements related to the multimedia traffic were also discussed. Then, a trust management framework was designed for cluster-based wireless multimedia sensor networks. The proposed framework can be used to next-hop selection in secure routing protocol. Finally, trusted QoS architecture was proposed. In the architecture, QoS manager observes and maintains information about QoS factors, and also responsible for QoS scheduling based on different QoS requirements. Trust Manager observes and maintains information about trust factors in WMSNs, and also responsible for trust computing based on different methods of trust factors aggregation.

Abstract: This article designed a circuit for alcohol measurements based on three-electrode biosensor. The circuit system includes MCU controller circuit, potentiostat circuit, scanning voltage circuit and current detection circuit. Potentiostat circuit is designed to keep voltage of working electrode constant. Scanning voltage circuit is to generate reference voltage by DA converter chip. Current detection circuit measure the response current on working electrode. The system can measure the current with the value less than 10^-9A, and the degree of accuracy of current can reach below 0.01uA. Different alcohol concentrations are tested based on this system and this system can get the concentration value of alcohol by the corresponding I-t curves.