Advanced Materials Research Vols. 490-495

Abstract: MMDB cluster system is a memory optimized relation database that implements on cluster computing platform, provides applications with extremely fast response time and very high throughput as required by many applications in a wide range of industries. Here, a new dynamic fragment allocation algorithm (DFAPR) in Partially Replicated allocation scenario is proposed. This algorithm reallocates data with respect to changing data access pattern for each fragment in which data is maintained in current site, migrated or created new replicas on remote sites depend on accessing frequency and average response time. At last, the simulation results show that the DFAPR is suitable for MMDB cluster because it provides a better response time and maximize the locality of processing so it could be developed parallel processing of MMDB in cluster environment.

Abstract: A jet cooling system is designed for micro Wankel engines in laboratory environment. The heat transfer on the wall of engine is simulated with FLUENT, from the simulation results we can see that the cooling effect of jet cooling system is good, it can meet the needs of wall temperature. This paper is helpful for the cooling of micro engines in laboratory environment.

Abstract: In order to realize the accurate serial communication, a simple and practical scheme for URAT design and implementation was put forward based on the analysis of CRC generation algorithm. The reliability of serial communication can be improved by adding CRC into the asynchronous serial communication. The CRC checksum module is achieved with Verilog language on the basis of FPGA and obtained consistence between the results of simulation and theoretical analysis. Therefore, the expected design target was met, and the communication speed and efficiency was improved.

Abstract: In this paper, a kind of pedestrian navigation system (PNS) that based on Earth’s magnetic field is introduced, and the error of the build-in electronic compass is analyzed, and an efficient calibration algorithm is presented. The PNS is determined pedestrian’s movement locus by calculating the heading angle and analyzing the movement characteristic, and then using the dead reckoning algorithm to combine the information together. The precision of PNS is affected by the error of the electric compass, because the heading angle is calculated from the magnetic field data measured by the compass. In order to reduce the measure error, a direct method which is used to calibrate the compass, based on ellipsoid fitting, is developed.

Abstract: PCNN model is particularly suitable for image segmentation and edge extraction, but its effect depends on the selection of parameters in PCNN model and network iteration settings, which needs for a large number of artificial interaction and has limited PCNN image processing practicality. In this paper, through combining statistical properties of images and PCNN model, we present an adaptive algorithm based on the distribution of pixels to replace the artificial interaction. Experimental results show that image segmentation using image enhancement and PCNN with adaptive parameters is significantly better than the traditional PCNN image segmentation and verify the effectiveness of the method.

Abstract: This paper describes the need for transformation of CNC machine tools, CNC machine tools and a brief introduction to the content and transformation of the advantages and disadvantages, but focuses on how the transformation of CNCmachine tools including CNC system selection, transformation NC modificationof the main mechanical components and CNC transformation of the main steps,and cited several examples of digital transformation, and finallyshows the numerical transformation of the problem and made recommendations.

Abstract: Estimation the shape and position of the objects is an important subject in ground penetrating radar(GPR). Migration method is popular used in seismic wave detection technology to locate and reshape the objects. Finite difference time domain(FDTD) migration method is widely used not only because the iterative method can save the computer memory but also because it is sensitive with different horizontal velocity and vertical velocity of electromagnetic wave. In this paper, migration imaging principle is been introduced at first, then FDTD migration method is been discussed. By dealing with GPR simulation and experiment image, it shows that the FDTD Migration method used in GPR imaging is effectiveness and stability.

Abstract: This paper concerns full-column rank solutions to the nonlinear matrix equation XA+XBX=HX, which is proposed from the so-called regulation problem of continuous-time (descriptor) linear systems with constrained states and controls. Sufficient and necessary conditions under which the nonlinear matrix equation has at least one full rank solution are investigated, and thereby, a mistake in [1] is pointed out by constructing a counterexample. Moreover, one full-column rank solutions to the nonlinear matrix equation is constructed.

Abstract: This paper introduces some commonly used methods for gearbox incipient failure diagnosis. Mainly stresses on the combination of autoregressive model filter and minimum entropy deconvolution filter which is sensitive to the impulsive component of vibration signal, as the preprocessing technology. Envelop analysis is then utilized to extract characteristics of gearbox failures. Simulating and real experiments show the effectiveness of this method.

Abstract: Due to equipment management status in power plants, a developing platform for equipment information management is suggested, including implemented functional modules: authority management, workflow management and business module management, etc. Based on this developing platform for equipment management, a variety of application programs corresponding with equipments can be developed flexibly, and information integration among applications can be carried out fluently.