Advanced Materials Research Vols. 225-226

Abstract: The superconducting magnetic energy storage system (SMES) has good characteristics such as high efficiency, quick response, no deteriorations, etc. However it is still far from wide application. The main obstacle is due to its high cost. One of the most effective ways to reduce the cost of SMES is to make it multifunctional. In this paper, a dual mode control strategy is proposed. With the proposed control strategy, The SMES can compensate voltage dip, current harmonics, reactive power, and active power fluctuation with a simple topology. The efficacy of the proposed control strategy is verified by simulation results.

Abstract: Software architecture design is one decision-making process for a series of major issues from software development and the best practices had been summed up. Nevertheless, the strict observance of the best practices still cannot raise the design line from the class development to framework development. The reason was that most imitators are unable to understand accurately the essence of two key words of "iteration" and "divide and rule". Therefore, this paper made further study of the "iteration" and "divide and rule". First, the meaning of "iteration" would be redefined. It is that each cycle should have a respective emphasis and end with the time deadline so as to make a clear distinction among them and improve iterative efficiency. Second, the meaning of "divide and rule" would also be redefined. It is that the passive decomposition based on Test First is better than active decomposition. Because it is the most suitable to have no alternative but to decompose according to current concrete conditions. By this way, best practices of architectural design can be implemented in real project, so as to improve the level of architecture design in essence.

Abstract: In an adaptive echo canceller, the detection algorithm able to distinguish echo path change (EPC) from double-talk (DT) is vital to ensure that adaptive filter tap coefficients are updated in case of EPC and frozen during the DT period. The paper presents a new echo cancel algorithm, which can protect the adaptive filter performance during double-talk in acoustic echo cancellation of teleconference without setting a detector. A judgment value can be directly used in the iteration formula to control the iteration speed of the filter, which composed of the correlation of the far-end signal and near-end received signal, the pre-correlation of the error signal. The computer simulation results verify that the mentioned algorithm has the good double talk protection performance, and it is very useful and efficient in distinguishing EPC from DT but with less computational complexity contrast to the congener algorithm.

Abstract: Based on the mathematical model of the step motor, a new method for modeling and simulation of step motor based on LabVIEW is proposed. The reasonability and validity are testified by the coincidence of the simulation and experimentation results and theory analysis. This method offers a new thinking for designing and debugging actual motors.

Abstract: Yarns were seen as having a concave-convex structure consisting of a main frame and a twisting according to their morphological structure and property. Simulation model of yarns was built by adopting the virtual reality technique and frame modeling method and texture mapping was used to enhance its trueness. With the surface algorithm NURBS and based on the twisting feature of yarns, the appearance model of yarns can be established by moving and rotating the section of yarns and fitting the control vertex obtained. The experiment shows that both the two methods realize the appearance simulation of yarns and meet the expected effect.

Abstract: With the rapid development of mobile communication technology, the short message name and address system [1] has been developed swiftly nowadays. We make the short message to be a kind of carrier, for delivering the requirements which clients required and return the answers which clients seek for. This paper contains such contents as follows based on the research of the system: analyzing the problems and defections existed in the system, enhancing the transfer mode to be a standard way, and improving the efficiency of data query and transfer. Taking advantages of the superiority of this system and innovate on the technology, we have completed a business software based on J2ME platform[2-7].In the research and development process we designed client-side functions and structural model combined with some functions used on the mobile phones, accordingly, the system technology has been practiced to some extents. And we optimize the software interface by a third party plug-in board called the “polish”, this work must will provide far-reaching significance for later research on this technology.

Abstract: A design scheme is proposed in this paper for wireless monitoring system of semi-lean pumps based on ZigBee and XBee-Pro module. The XBee-Pro module is placed inside the semi-lean pump to monitor the working parameters. The monitoring data is transmitted to the computer in the monitoring and control center by means of ZigBee through routers and coordinators. System tests show that wireless network system based on ZigBee and XBee-Pro module is convenient to use and reliable to transmit monitoring data.

Abstract: Computer vision community has long attempted to automatically detect locations in the image that are able to capture attentions of users. In recent years, more and more researchers have proposed to address this problem from the perspective of simulating human visual attention mechanisms. In this paper, we study modeling visual attention in frequency domain. Our major contributions are twofold: 1. A new method called band-divided method (BDM) is developed to generate the saliency map by integrating the amplitude spectrum with the phase spectrum. 2. A quantitative measurement according to min-distance dissimilarity (MDD) is presented to evaluate the saliency map, which is more appropriate for non-binary ground-truth data. Experiments on benchmark dataset and comparisons with traditional approaches demonstrate the promise of the proposed work.

Abstract: By taking voice traffic system as study object, mathematical modeling methodology was used to investigate different parameters’ variations on system’s performance. Firstly, on the basis of analyzing the characteristics of voice traffic, this paper constructed a Stochastic Petri Net (SPN) model for ON-OFF voice traffic system. Furthermore, average time delay of the system was analyzed and model-based simulation was conducted with Stochastic Petri Net Package (SPNP) 6.0. For different parameters of ON to OFF rate and user’s voice connections, variation trends of number of user’s connections and ON to OFF rate are derived thereby. The methodology of modeling and simulation in this paper can be further used to analyze the performance of multimedia hybrid traffic system.

Abstract: Considering common mode failure (CMF) in the rendering cluster systems, the availability of rendering cluster systems with the increase of cluster’s number was studied. Firstly, based on availability of system with one cluster node, system with two cluster nodes was modeled with continuous time markov chain (CTMC) model. Then, the CTMC model was extended to the case of system with three cluster nodes. Furthermore, by solving these three CTMC models, availability for different cases were numerically deduced. Additionally, during one year the unavailable time for different cases was calculated and analysis by comparison was conducted. Finally, conclusions on different cases’ advantages and disadvantages are derived thereby, which offers theoretical foundations for establishing rendering cluster systems.