Applied Mechanics and Materials Vols. 198-199

Abstract: Mobile payment is the most import part of mobile E-commerce. Currently there are many different types of technologies that can implement the mobile payment. J2ME is one of the best for its more popularity and convenience. The paper focuses on discussing the architecture of J2ME, and compare WAP and J2ME from various aspects, giving a general feasible J2ME-based design and overall framework of mobile payment system.

Abstract: With the urgent needs of improving spectrum’s efficiency, dynamic spectrum allocation based on auction has become a popular method, which makes unlicensed users to use the vacant spectrum released by primary users. However, the collusion behavior between unlicensed users harms system’s efficiency and profit. Although many kinds of mechanism have been proposed to solve this problem, resisting collusion is still a tough problem. In this paper, we study the nature of collusion behavior and revenue, and model a multi-stage auction for centralized spectrum allocation. In order to balance the collusion-resistance and revenue-optimization, we propose an algorithm with unit price priority and one step revenue optimization, which can combat collusion between unlicensed users and encourage them to compete with each other so that improve system’s total profit to some degree. With the simulation results, our algorithm shows a good performance on collusion-resistance and system’s revenue comparing with the other two algorithms.

Abstract: A wide-band antenna coupling with an elliptical slot was discussed in this paper. To implement the wide band operation, an elliptical ring slot was etched on a polygonal patch. The properties of this design have been verified by using electromagnetic simulation software. Comparing to the conventional U-slot patch antenna fed by Π-shaped slot, the proposed structure is with the same impedance in bandwidth, but less than 10% in size.

Abstract: The Internet of Things technology has brought the worldwide wave of the information industry, has increasingly become the focus of attention in all areas of the world. In this paper, the concept of Internet of Things, the basic structure, its key technology, simply talking about the linkages between the Internet of Things and Automation as well as the automation industry, and cited a number of related applications of the Internet of Things technology.

Abstract: Wireless technology has walked into the People's Daily life, Bluetooth technology comes to the fore in so many wireless technologies with its low power consumption, low cost and other characteristics. Bluetooth technology is used widely, we can see it in mobile phones or in our cars, it seems that Bluetooth technology has penetrated into every aspect of our lives. Even so, the combination of Bluetooth technology and fixed telephone still has a very big development space. If the stability of the fixed telephone combined with the flexible of Bluetooth technology, it will give the life of people a lot of convenience. This paper will introduces the Bluetooth hands free system for fixed telephone, it is such a product that it will make Bluetooth technology and common fixed phone combined, and make it a reality that people can use common Bluetooth headset to answer or call a fixed telephone.

Abstract: The fast temporal variations shallow water acoustic (SWA) channels need the temporal variations channel coding scheme at the acceptable cost. Hence, flexible channel coding rate, adjusted according to different ocean channel characteristics, should be desired in the design of practical error control SWA communication system. In this paper, we propose rate-compatible LDPC (RC-LDPC) codes to improve the communication system reliability for SWA communications. The proposed SWA system adopting RC-LDPC codes consists of three important preprocessing: channel state information (CSI) estimator, signal-to-noise ratio (SNR) estimator and RC-LDPC pattern. For the estimation error, we define and derive the sensitivity to imperfect CSI and imperfect SNR. Then the design of RC-LDPC codes and SWA channel profile are described. Furthermore, the RC-LDPC performance pattern is given and sensitivity to estimation error of CSI and SNR are analyzed via simulation. It is shown that RC-LDPC codes have good performances with wide range of rates in SWA channels. Finally, coding rate distributions of RC-LDPC codes in different SNR at BER below 10-4 for SWA channel are investigated.

Abstract: With the growing maturity of the Bluetooth technology, Bluetooth technology to the utility and safety are getting higher and higher. As open-standard of short distance wireless technology of communications. Bluetooth has much virtue of low-power consumption, low-cost and strong anti-interference. It is convenient and economical when used by mobile devices in Small scope. This thesis summaries the background of the thesis, also simply illustrates Ad Hoc network and the application of Bluetooth in Ad Hoc network. At the beginning of this article, the main research task and arrangement of chapters are introduced. Introduce Bluetooth technology and architecture. Based on the introduction of the system module of Bluetooth personal area network (PAN), implementation of the application module of PAN is presented. The implementations of software and hardware platform of Bluetooth ad hoc are also presented. An application of Bluetooth ad hoc---wireless communication positioning system based on Bluetooth, GPRS and GSM is designed and realized. Finally, Summary of the main technology and project, summarize the relevant work of the thesis.

Abstract: The distributed optical fiber Raman sensor system was widely used for real-time measurement temperature, but the Anti-Stokes and Stokes scattering Raman signal is very weak. In order to improve measurement accuracy the signal must be denoised before obtaining the temperature. In this paper, a new noise cancellation of empirical mode decomposition is proposed for enhancing signal-to-noise ration of the Anti-Stokes and Stokes scattering Raman signal. The signal-to-noise ratio was enhanced by using this method and it is easy to be realized in computer.

Abstract: Numerous technologies have been adopted in modern SATCOM to ensure communica-tion smooth. Among them, frequency hopping and onboard processing technology will be researched mainly in this paper. First, models of frequency hopping system and onboard processing system were built by Simulink. Then, the effect of coupling phenomenon analyzed on the theoretical. At last, Anti-jamming capability studied after simulating with different jamming. All above will provide convincing support to further research on SATCOM technologies; also, will guide the development of satellite communication.

Abstract: Flexible Bandwidth Optical Networks(FBON) can improve spectrum usage rates comparing to traditional WDM networks, leaving one critical problem of spectrum fragments. This paper proposes a novel defragmentation scheme that determines the sequence of connections going through defragmentation processes. In sequencing connections, priority zones are divided and priority levels are set accordingly. Bandwidths or path lengths are what make a difference in a connection’s priority. As simulation results show, priority-based defragmentation scheme can achieve lower block rates as well as lower interruption rates. The simulation results also prove the preference of local defragmentation to global defragmentation and the preference of narrow-band defragmentation to broad-band defragmentation.