Applied Mechanics and Materials Vols. 490-491

Abstract: Loudness describes the sound intensity sensations of the human hearing. A study about loudness calculation which is based on the Moore model shows us that starting from the mechanism of human`s ear, the basic principle and calculation skills of algorithm have been researched. By using Matlab to optimize the algorithm, the specific loudness curve and loudness level of any audio file can be calculated; equal-loudness curve by using Steffensen method is calculated compared with that from the acoustic standard, In order to validating the program. The loudness of the sewing machine under different conditions is calculated.

Abstract: This paper proposes an approach to improve the reality effect of fabric dynamic simulation based on mass-spring model. The major problem encountered in fabric dynamic simulation is the difficulty to determine the characteristic of material and the changes of deformation force. To solve this problem, feature points motion constraints are introduced into the mass-spring model. This paper also establishes a framework of an approach to recover feature points motion based on non-rigid motion trajectory representation model. Then the recovered 3D estimation of the fabric feature points are used to adjust the simulation computing process of the mass-spring model, and simulation results with good reality are obtained. The experimental results for fabric dynamic simulation demonstrate the feasibility of improving the reality effect by the proposed motion-estimation-drive approach.

Abstract: The EBH300 Roadheader is one of the important equipment in laneway excavation of coal mine. It composed of mechanical, hydraulic, electrical and control systems, and covered cutting, shipment and travelling. Because of its hard working conditions, the complex cutting force and load fluctuation and vibration during the working process, the mechanical parts design plays very important roll to the EBH300 Roadheader. The 3D models of the EBH300 Roadheader were built based on the engineering prototype. The mechanical characteristics were studied for further development, which included mechanical structure, the vibration modes of the cutting parts, maximum amplitudes by modal analysis. According to the result, more attention must be paid to the complex force condition, violent and irregular vibration of the cutting parts in the design.

Abstract: Abstract. In this paper, we have discussed the principle of the flexible blank holder forming ( FBHF) technology, and established the finite element model of medal deep drawing process based on FBHF. Then we have discussed the FBHF technology by analyzing the system of finite element model. By simulating the forming of rectangular box, we can conclude that FBHF technology will have a greater advantage when the depth of stamping forming is much deeper. We have also compared the thickness distribution parameters, wrinkling parameters, and spring back parameters of rigid blank holder forming parts with FBHF parts. The result shows that the forming parts of FBHF technology has uniform stress and strain distribution, small spring back, the quality of inhibiting wrinkling, crack and other defects.

Abstract: The paper studies an asynchronous multi-sensor fusion problem based a kind of asynchronous multi-sensor dynamic system. Firstly, this paper presents a centralized fusion algorithm based on the Kalman filter without ignoring the correlation between process noise and augmented measurement noise. It is optimal in minimum mean square error. Then using the steady-state Kalman filter to estimate and fuse. Secondly, in the condition that the local sensor estimation error is associated, a distributed fusion algorithm is given by utilizing S.L. Sun optimal information fusion criterion in minimum error covariance matrix trace at fusion center. In distributed algorithm, the value transmitting to the fusion center is determined by the local sensor estimation based on the steady-state Kalman filter and one step predictive value. Since both optimal fusion algorithm standards are different, so the fusion precision will vary. Finally the effectiveness of the algorithm is verified by computer simulation.

Abstract: In order to study the effect on the structure of pressure-released hole combined support with rockbolt under dynamic loading, utilize RFPA^2D-Dynamics on a numerical simulation of dynamic responses of roadway surrounding rock under different depths and different continued time of stress wave and different amplitudes of stress wave. It had gained the general law of the stress redistribution of roadway surrounding rock under static-dynamic coupling loading, and analysed the damage effect of static-dynamic coupling loading to surrounding rock from the perspective of acoustic emission energy release and failure units. Studies show that dynamic disturbance is the main inducing factor on instability of deep roadway supported by pressure-released hole combined support with rockbolt, the waveform of dynamic stress has important influence on broken surrounding rock, with the stress amplitude is the higher and the action time is longer, dynamic disturbance on stability of roadway bring about more significant effect would become.

Abstract: Inverted pendulum system is the ideal study object of nonlinear system. The ADRC has good estimate for disturbances, strong robustness and using static decoupling instead of dynamical decoupling. The one-level inverted pendulum system can be regarded as composing of the pendulum angel system and the cart position system. The former is faster and the later is slower. The synthesized ADRC for one-level inverted pendulum system is built through combination of separating and assembling to reduce difficulty in optimizing ADRC parameters of the inverted pendulum system. The synthesized controller is simulated by Matlab under different parameters of the inverted pendulum. Simulation results show that the pendulum angle and the cart position are well controlled.

Abstract: . The Temporal logic of actions TLA is a logic for specifying and reasoning about concurrent systems, which make systems and their properties are expressed in the same logic. In this paper, we introduce the concurrent programming languages and behavior semantics, mainly describe safety properties and liveness properties in TLA and take NeedhamSchroeder symmetric key protocol as an example to illustrate how to specify these properties in concurrent program by TLA.

Abstract: This paper addresses the problem of the dynamic positioning system of surface ships in the presence of constant environmental disturbances. In this paper we propose a high-gain observer-based PD controller to estimate unmeasured velocities of a surface ship. Lyapunov stability theory is applied to prove its stability. Finally, simulation is carried out using SIMULINK and appropriate results are obtained to illustrate the effectiveness and performance of proposed controller.

Abstract: With the development of computer technology and the Internet, mobile learning has become more important in E-learning applications. Being freed from traditional fixed locations and times for the unilateral learning of formal curricula, a learning style allowing for adaptation and interactivity as well as ubiquitous learning has emerged. From the perspective of cognitive apprenticeship, in which learning cognition is guided by experts, and the executive process of missions, objectives, and capacities is manifest, the master can observe and discuss with the apprentices, and revise it toward a well-mixed interactive process, promoting learner ability in diagnosing and reflecting upon errors. This study uses the electronic cognitive apprenticeship system as the basis to integrate and construct a mobile digital content learning community. Through the handheld devices or mobile devices used by learners connected through wireless Internet, learners can read and learn digital content on computer hardware fabrication. The learning behavior recorder for enhancing learner learning activity, which integrates records for tracking and learning processes for the learner, in order to conduct master discussion and guidance for apprentices in electronic cognitive apprenticeship.