Applied Mechanics and Materials Vols. 602-605

Abstract: Visible light communication (VLC) is an optical wireless communication technology that uses visible light emitting diodes (LEDs) as a communication source. Since the LEDs are also used for illumination, the cross-section emission effects of the LEDs need to be analyzed as they apply to indoor VLC channels. In order to evaluate the illumination and communication performance according to the emission cross-section pattern, a simple LED model with a quasi-elliptic emission cross-section is proposed and compared to a circular LED model. The LEDs with a quasi-elliptic emission cross-section provide less fluctuation in the illumination and optical power distribution at the receiving plane. The four-transmitter VLC system is found to support at least at 30 and 33 Mb/s for circular and quasi-elliptic emission cross-section LEDs for the entire receiving plane, respectively.

Abstract: A new combined method of wind power prediction based on entropy method is proposed according to information fusion technique. Firstly, Carry out the wind-power forecast with BP neural network, radial basis function neural network and support vector machine respectively. Then, weights of combination forecasting can be obtained according to the degree of variation of prediction error sequence. Case study was carried out to investigate the validity of the novel algorithm and the results illustrated that the proposed combined model can improve the short term forecasting accuracy of wind power effectively by tracking the change of wind power.

Abstract: In this paper, we construct a second-order two-scale (SOTS) finite element method for piezoelectric problem in composite plate with 3-D periodic configuration by means of construction way. Based on the Reissner-Mindlin deformation pattern and integral projection operator of electric field, the homogenization solution of piezoelectric problem is obtained based on finite element method. The SOTS's computational method is constructed by SOTS's asymptotic expansion. A set of numerical results are demonstrated for predicting the displacement and temperature of composite plate. It shows that SOTS's finite element method can capture the 3-D local behaviors caused by 3-D micro-structures well.

Abstract: According to the requirements of general surgical operation, we designed the plasma therapy system which took the microprocessor as the control core based on medical low temperature plasma technology. Making use of High-frequency AC electric field exciting ions in the electrolyte can generate low temperature plasma. Conclusion: the low-temperature plasma therapy system can significantly reduce blood loss and length of incision, shorten operating time, and postoperative complications in general surgical operation.

Abstract: This paper introduces a kind of spectral data acquisition system based on the linear CCD. The spectral acquisition circuit, data conversion and storage circuit were designed. The synchronization of the spectral data acquisition, data conversion and storage were achieved using VHDL. Finally, the spectrum contained noise is processed by the wavelet denoising theory. The experimental results show that the proposed scheme is feasible.

Abstract: The paper studies a beamforming technology based on injection-locking technique, which is suitable for phased array. In the second section, the article designs a novel beamformer based on injection-locking, which can realize arbitrary phase weighting vector without phase shifters. The third section, the feasibility of the technique is verified by experiments.

Abstract: The stability of Border gateway protocol (BGP) are directly related to the performance of the Internet. However, experiments show that BGP has serious slow convergence problem and its performances cannot meet communication needs well. Thus, a BGP fast convergence mechanism based on doubtful path judgment is proposed in this paper. Firstly, by analyzing the relationships between failure paths, doubtful paths containing failure links are computed. Secondly, a policy of doubtful path validity inquiry and its corresponding messages are designed to avoid computing wrong doubtful paths while multiple links fail simultaneously. Meanwhile, in order to avoid the waste of network resources caused by the policy, a finite state machine is designed to handle nodes’ state transitions. Finally, doubtful paths are suppressed to take part in routing decisions in the stage of BGP path exploration and the fast convergence is achieved. The mechanism is implemented on the prototype system, and its validity and practicability are tested. Experiment results show that the mechanism is feasible and effective.

Abstract: IPv6 is the core protocol of Future Internet. Thus, IPv6 based QoS (Quality of Service) routing mechanisms need to be developed to support diverse QoS requirements of new network applications. In this paper, an IPv6 based QoS unicast routing mechanism is proposed based on OSPFv3 and BGP4 +. By introducing QoS state message and extending the link state database and link state advertisement, the collection, storage and release of intra-domain QoS information are realized. By introducing NLRI (Network Layer Reachability Information) which supports QoS, the release and revocation of inter-domain QoS routing information are realized. The mechanism not only provides QoS support, but also is compatible with the existing routing protocols. It can be quickly and effectively deployed in networks. A prototype implementation of the proposed mechanism is completed, which is tested under a video conference application over the CERNET2 topology. The results indicate that it is feasible and effective with good performance.

Abstract: Nowadays, Internet has been flooded with spams, which not only disrupts routine network application, but also affects people’s normal life and work. Thus, an accurate and effective spam filtering scheme is indispensable. In this paper, the scalable decision tree is utilized to analyze feature information of email-header to obtain anti-spam rules, which can be further used to filter spams. As is shown in the test result that the proposed scheme has satisfying performance and it is feasible in spam filtering.

Abstract: The popularity of mobile communications and coexistence of heterogeneous access networks make it possible that the person can achieve the communication business with little restrict, which requires the support of ABC (always best connected) and the guarantee of users’ QoS requirement. For the property that the network status and users’ QoS requirements are difficult to get, this paper proposes an ABC supported heterogeneous access networks selection mechanism based on the particle swarm optimization based on adaptive diffusion and hybrid mutation in view of users’ preference, users’ cost and network providers’ income. The simulation result shows that this mechanism can not only satisfy the users’ requirements, but also maximizes the utility of both sides.