Applied Mechanics and Materials Vols. 58-60

Abstract: In this paper, a novel mobile robot is introduced. The mechanical structure, control system and the simplified dynamic model of the robot are given particularly. Moreover, the pose and velocity control strategies of the robot is presented respectively. Finally, the mechanical structure and control strategies are validated through a series of experiments.

Abstract: Fixed Mobile Convergence (FMC) provides a solution of the converged access network for wired and wireless network. PON and WiMAX are the typical representatives in fiber access network and broadband wireless access network, of which the convergence has great research value. The converged network of PON and WiMAX has the advantage of high-bandwidth, which can provide various kinds of broadband access services and has features of low cost and simple and flexible. There are a variety of system forms for PON technology, one of them with unique advantages is WDM-PON system. In WDM-PON systems, each service has exclusive transmission bandwidth, which makes the converged network of WDM-PON and WiMAX has much more advantages than any other PON network. This paper proposes a converged network model of WDM-PON and WiMAX, and focuses on the analysis of dynamic bandwidth allocation algorithm applicable to the converged network model; then does some simulation of this dynamic bandwidth allocation algorithm, proves that the algorithm has a good delay effect in overload conditions, and analyses the bandwidth rate taken by traffic flow of different service levels under different network load situations.

Abstract: In distributed data storage, a particular dataset can reside at multiple locations in order to get high availability .Thus, the dataset can be downloaded in parallel from multiple nodes.Throughput between server and client changes dynamically, so the downloading speed can vary unpredictably. A dynamic parallel downloading algorithm based on measurement of bandwidth and bandwidth prediction is produced in this paper and server caching is adopted in order to improve downloading speed. The algorithm dynamically adjusts downloading of the last block to make parallel downloading from multiple servers end almost simultaneously. With this approach, the download time is reduced and the robustness of the downloading system is improved. Besides, the algorithm not only avoids complicated server selecting mechanism, but also improves load balance of the servers.

Abstract: With the rapid progress of standardization of 3GPP’s LTE (Long Term Evolution) and LTE-Advanced, many research attentions have been focused on the link level evaluations of the 3GPP LTE systems, so as to demonstrate the rationality of novel transmission techniques. Different from theoretical studies, incorporating novel transmission techniques in to the LTE communication systems may affect many parts of the systems, such as signaling process, reference signal design, feedback link design, and compatibility, etc. Link level studies might be too simple to evaluate the benefits of these novel techniques to the entire system. On the other hand, system level simulation concentrates on the performance of the entire network with tens of cells and hundreds to thousands of users. It is possible to illustrate the actual performance of a LTE system by simulations designed from a system standpoint. Since the simulated system is quite large, one can understand the speed of simulation is very important for system level simulation platform. In this paper, we propose a design of Matlab-based 3GPP LTE system level simulator, which makes use of parallel computing techniques supported by NVidia GeForce GTX 260 graphic card. Our simulation experience shows that the simulation time reduces by nearly 1/3 after employing parallel computing techniques.

Abstract: As the development of the modern workshop, the demand for water supply and heating system is more and more important. This paper comes from the faw-volkswagen company’s construction project about the automatic water supply system of one of its workshop. For many reasons, the conventional PID control can't satisfy the workshop’s demands for the certain temperature, after a careful research of the system, we utilize the principle of fuzzy PID adaptive control to design a fuzzy PID controller, then put it into the water tank heater’s controlling, through the practice, we find the controller has a good robust property and reached the practical production needs.

Abstract: Virtual prototype plays an important role in agile designing and manufacturing. Finite Element Analysis and multibody analysis software can also assist engineers with developing and analyzing sophisticated machines. In this paper, a virtual model of an automobile wiper is modeled and used to be simulated under virtual environment of ADAMS, which is a famous tool in mechanical engineering. After simulation, the vibration and noise that the wiper works with have been found and some suggestions are given in discussion and conclusion.

Abstract: This article mainly discussed the management of play buffer in streaming multimedia system. Based on this problem, this article raised one idea: dynamic suly:demand , besides this,also raised that the newly joined nodes should request data whose number is near , n stands for the lowest block number in play buffers of the newly joined node's all partner nodes , m stands for the highest number. These two ideas are used to assign the data blocks that have been played with covering priorities, the higher the priority is, the more possibly it will be covered . Lots of experiments proved that through using ideas this article raised, the success rate of requesting data from partners is increased in each node in the condition of not affect playing quality.

Abstract: Consumer electronic products have become an indispensable part of living for people with the development of information technologies. Crystal oscillator, CXO, a frequency controlling component, which is needed by communication-related industries, is widely used in expensive electronic products like mobile phones, notebook computers and GPS for its outstanding features of stability in temperature and low wearing. In CXO products, wires of ill quality are very likely to lead to ill contact between signal connectors and gold wires on IC or broken wires, which would cause the whole IC-packaged product unable to work normally. This article, thus, will develop a model of assessing and testing process capabilities with process capability index, C_pl, specifically for the larger-the-better quality characteristic of wire process. The article will also provide the assessment procedure, whereby the industry can effectively evaluate whether the process capabilities of their products meet the benchmarks they are supposed to.

Abstract: Space-time coding has the advantage of simplicity on coding, easy to achieve full diversity transmission, and low complexity on decoding. Based on the estimated inequality of the expectation of a random variable function, block error rate of the orthogonal space time block decoding is analyzed, and a new upper bound on the symbol error rate is achieved. Precoding criterion on orthogonal space time coding has been proposed based on the new upper bound. The solving complexity of the precoding matrix is reduced effectively. Simulation results show that bit error rate of the precoded system is lower than that of the without precoding.

Abstract: Design is one of the main activities in industrial manufacture. Researchers in the design field have an increasing number of opportunities to analyse design documents. Some researchers have sought to explore the natural language in these documents, or the design documents. This paper briefly reviews previous research in design document. By describing and analyzing the existing methods, it identifies the gap for the computational linguistics in design documents.