Advanced Materials Research Vols. 472-475

Abstract: The controllable hydrogen storage on single wall carbon is studied by using the first principle based on density functional theory (DFT). It concludes that the adsorption of hydrogen on the bare distorted single carbon nanotubes (SWNTs) can be enhanced dramatically when the single wall carbon nanotubes are rotated along the tubs axis and depend on radius of SWNTs. The binding energy decreases as the radius increase.

Abstract: Utilization of safety barriers is one of the most common methods for immunization of road sides. These barriers will redirect deviated automobiles onto the right path and will also prevent overturning and hitting dangerous obstacles. This will reduce fatality and injury. Regarding the roads condition to obtain more safety in Iran, this paper has concentrated on the safety barriers survey, and the behavioral based on their type, the road's condition and also related economical evaluation. To obtain the above mentioned aims, in addition to investigating the pre-performed study, surveys around the world and the current status of the safety barriers in the country, the preferred option will be chosen and then introduced based on the performed technical and economical comparing between two common barriers in Iran. Taking into consideration the executive facilities, and current technical and economical conditions.

Abstract: Abstract. This paper investigates leveling control system of suspended access platform using an observer-based controller. Uncertain linear systems for leveling control are derived and represented in terms of a set of matrix inequalities. In the system, all state variables needn’t be measured; the perturbations of leveling control are assumed to be described by structural uncertainties. The stiff problem is avoided since the design procedure is independent of the small parameter. The control problem can be effectively solved by the proposed iterative linear matrix inequality approach. The convergence of the algorithms is also studied. Furthermore, a numerical example and simulation results are given to illustrate the effectiveness of proposed method.

Abstract: The three styles of procuring agricultural means of production were compared to explain the theoretical basis to build the strategic alliance. And related indicators ,for example purchasing price, quantity and the total profit are compared in different relationship between agricultural means suppliers and farmers by building mathematical model .In the end, it is concluded that if the farmers form horizontal alliances, and then, form strategic alliances with suppliers, the system’s related total profit is the most. Owing to construction of strategic alliances, not only the profits of suppliers can increase, the costs of famers also reduce.

Abstract: This paper presents a novel design scheme on USB key device. The design use Oregano Systems 8051 IP core. Compared with the standard 8051, Oregano Systems 8051 has 10 times the performance improvements at the same frequency. Details of the design internal structure and novel online debugging mechanism are introduced. The design allows online debugging on USB key, greatly accelerates the development process. The design has been implemented on Altera’s Stratix FPGA and got practical verification.

Abstract: In order to acquire enough energy, high power pulse must be used to drive a piezoelectric transducer. At the same time, it is a key technology to design an impedance matching circuit between a signal generator and a piezoelectric transducer so that signal source can transmit energy to the piezoelectric transducer effectively. In the paper, the impedance matching theory is analyzed. And, a method of using an oscilloscope to measure resonance frequency of the piezoelectric transducer is tested, through which, a perfect matching circuit is designed.

Abstract: The Unmanned helicopter (UMH) movement was divided into two parts, namely, attitude and trajectory motion. And then a two-timescale nonlinear model was established. The paper improved and expanded state dependent riccati equation (SDRE) control approach, deriving analytical conditions for achieving global asymptotic stability with lyapunov stability theory. Proof was given. By combining improved SDRE control with nonlinear feed-forward compensation technique, the full envelop flight attitude control laws could be designed. On the basis of attitude control, trajectory controller was developed. Actual flight tests were carried out. Test results show that the control strategy is highly effective.

Abstract: A new rational peak overpressure formula about scale distance has been summarized by comparing differences of domestic and foreign scholars’ empirical formula. AUTODYN has been used to simulate the shock wave in the air by taking different mesh sizes. Comparing the numerical simulation results and empirical formula results, only when the scale distance is too small, two results about peak overpressure have certain deviation. But both results about positive pressure time are similar.

Abstract: Aiming to the multi-variable, non-linear, high-order, close coupled, inverted pendulum system, a mathematical model of the inverted pendulum was established. The LQR controller was put forwards according to this model. In the LQR controller, the selection of the weight matrix Q and R directly impact on structural dynamic response and controlling force. How to determine the optimal Q and R to obtain the global optimal control is still a problem. The matrix Q and R were optimized based on genetic algorithm with different objective functions and the results were verified here. The simulation results show that the optimal preference weighting coefficient were obtained by genetic algorithm and the satisfactory factors can be selected by the designer according to the preference, while the subjectivity and blindness of the conventional method have been overcame.

Abstract: The customer characteristic-driven innovative design method for glasses was described. A pair of glasses is a special product that should provide not only the perfect functions but also the “aesthetic emotion”. Thinking of these needs of users, the physiological characteristics were extracted from the user’s measurement data of head and face, and the psychological characteristics were identified based on user’s perceptual evaluation experiments at first. Secondly, the mathematical descriptions of different glasses components could be established to form the “component product families”. And then, the corresponding components of “product family” could be identified and selected based on the user’s features, and the product layout of the whole glasses could be achieved by the visual-interactive optimization method.