Advanced Materials Research Vols. 588-589

Abstract: In order to expand the traditional applications on the desktop to smart phones, this paper designed a portal to integrative data platform for the power dispatching system based on android. The system releases data from Oracle database in the server of the dispatching center and lays them out, using MVC mode. And the system uses Web Service as middleware. The result proves that it is feasible and practicable.

Abstract: In this paper, we proposed an improved algorithm of hand-gesture recognition based on Haar-like features and Adaboost. Initial, we calculated the Haar-like features of hand-gesture images by integral image. Then, we used the principal components analysis method to reduce the dimension of Haar-like features. At last, an Adaboost classifier performed the hand-gesture recognition task with the hand-gesture features. A dataset with large hand gestures (12 types, 600 hand-gesture images) was built, including some large pose-angle (about 40 deg.) hand-gesture images. Our experiment results demonstrated that our method could effectively recognize different hand gesture, and the best appropriate N was 12. In addition, the average processing time of the proposed method was about 0.05 second for every image.

Abstract: By combining three-dimensional panorama technology with geometric modeling technology, the models of the primary and secondary equipment of substations are built to get a three-dimensional (3D) virtual environment. This method makes it easy to view the equipments and improves the integration of substation monitoring information. This paper analyzes and discusses two kinds of solutions which are based on Virtual Reality Modeling Language (VRML) and Open Scene Graph (OSG) together with Qt as the main technologies.

Abstract: Polycrystalline diamond, (PCD) is currently used in the industry for cutting tools of difficult-to-machine materials because of its superior characteristics such as hardness, toughness and wear resistance. But the PCD material is difficult to machine due to its above properties. Before making the PCD blank in varies tools, the lapping process is essential and necessary. The lapping quality depends heavily on the parameters. Therefore it is of great significance to study the path and velocity of lapping process for ensuring the lapping quality and uniform wear of abrasive disk. In this paper, on the basis of kinematics and geometry principle, the path equation was established. The complicated lapping process can be converted into two rotation movements, i.e. the movement of part against the center of lapping disk and rotation of fixture around its center. The relative path and relative velocity of random point of the part against abrasive disk were also analyzed and calculated. The computer simulation software was developed for figuring the path curves and instantaneous velocity of the lapping process. The results show that the abrasive disk can wear uniformly and the lapping quality can be raised. The application of computer simulation software provides the possibility to analyze the lapping principles, which is a simple, convenient and effective method.

Abstract: In order to generate more complex chaotic attractors, a seven-dimensional chaotic system is constructed, and relevant chaotic attractors can be obtained by Matlab numerical simulation. Lyapunov exponents validate that the system is chaotic. Implementation circuit of this system is designed, and circuit simulation can be done by using Multisim. Circuit simulation result is identical to system simulation completely. Chaotic behavior of the system is proved farther. A new chaotic signal source is provided for practical application based on chaos such as secrecy communication and signal encryption fields.

Abstract: Based on external characteristic test, the performance of designed axial-flow model pump was determined. Combingmixture N-S equations with RNG turbulence model and full cavitation model, the cavitation flow in tip clearance of axial-flow pump at flow rate of best efficiency point is simulated. The results show that the incipient cavitation region is located in the leading edge of tip airfoil. With the decrease of cavitation number, the cavitation region at tip airfoil moves gradually from leading edge to trailing edge. The development process of cavitation can be divided into three different stages and the typical characteristics of each stage are given

Abstract: Shield cutterhead is the key part of tunneling construction machinery. Because the cutterhead can cut the front soil by the cutter on the cutterhead, it’s of great significance for the design of the cutterhead to research the dynamic process of cutter cutting. With using extended Drucker-Prager constitutive model and damage model which has element removing function, the properties of soil material can be simulated more practically. The results also provide a simulation method of soil material on researching cutterhead tunneling process. Combined with finite element dynamic contact characteristics, it is obtained the regulation of cutting force changing with time and cutting force value in the process of cutter cutting. The results also offer a engineering parameters for researching the load state of cutterhead tunneling.

Abstract: In order to study the dynamic changes of the internal flow field physical quantities in the hydraulic buffer of a special equipment, based on the Computational Fluid Dynamics (CFD), a three-dimensional incompressible and viscous model under unsteady condition is created. The model keeps the control rod of varying diameter and non-working chamber cover, simulates the turbulent in the flow field of the hydraulic buffer of the special equipment with dynamic meshing technology. From the results, the distributions of velocity in flow field and pressure in chamber are got. It shows that there are negative pressure areas in the non-working chamber and that will lead to cavitation. The results give us a great reference to improve the structure of hydraulic buffer.

Abstract: In this paper, double crank mechanism is put forward to achieve separation of the processing tomato fruit-stem on the basis of analysis of the existing separation mechanism kinematic characteristics, and the rod length ratio of the desired motion characteristics has been gotten by virtual simulation platform based on ADAMS, and the rod lengths of the double crank mechanism ultimately determined are as follows, driving crank is 148mm, active crank is 178mm, link is 222mm, and driven crank is 200mm on the basis of the testing determination of the maturity processing tomato fruit-stem separation force. It is able to meet the fruit and stem separation requirements when the angular velocity of driven crank is 60r/min. It can provide a theoretical basis for engineering practice.

Abstract: Being an important blanking parameter, the blanking allowance of fine-blanking with negative clearance has a direct relationship with the quality of work piece and ejector force. The full process of fine-blanking with negative clearance for ASTM-1022 in different blanking allowances is simulated through the finite element analysis software DEFORM-2D, then the ejector force under different blanking allowances is measured through the experiment of fine-blanking with negative clearance. Based on the analysis of the ejector force, the proportion of burnish band and the work piece fracture, the following conclusions are summarized. The size of blanking allowance is not related with the blanking force with the sheet entering plastic state and the maximum blanking force, and is only related with the ejector force. When the value of the blanking allowance is between 0.1mm and 0.3mm, the friction force between the punch-die and the sheet affects ejector force, and the ejector force is not related with the mechanical properties of material. When the value of the blanking allowance is between 0.5mm and 0.8mm, with the blanking allowance increasing, the ejector force increases rapidly.