Applied Mechanics and Materials Vols. 325-326

Abstract: Speech endpoint detection plays an important role in speech signal processing. In this paper, a method of speech endpoint detection based on empirical mode decomposition is introduced for accurately detecting the speech endpoint. This method used in speech signal decomposition gets a set of intrinsic mode functions (IMF). An IMF which contained a lot of noise must be filtered, and the rest of IMFs can be reconstructed to a new speech signal. The speech endpoint is detected by average magnitude difference function precisely. Simulation experiments show that the method proposed in this paper can eliminate the impact of noise effectively and detect the speech signal endpoint accurately.

Abstract: This paper puts forward a finger vein classification algorithm which combines Principal Component Analysis (PCA) with Radial Basis Function (RBF) neural network algorithm, named the PCA-RBF algorithm. Use the training sample to reduce PCA dimensions, and abstract the main component of the image. Because of the advantages of RBF neural network classifying, put finger vein images into different classes, and then use the shortest distance to recognize. Through the experiment result comparing with Back Propagation (BP) neural network, PCA-RBF neural network is better in finger vein recognition. The result shows that PCA-RBF has faster training speed, simpler algorithm and higher recognition rate.

Abstract: The mobile storages especially in mobile devices hold a lot of important and private data. The portability and mobility may lead to loss and theft, therefore security problem of mobile storages and mobile data may suffer from troublesome and damage. TCG provides TPM for trust and security management. It is insufficient with mobile storage devices because mobile storage devices are often separated and load with heterogeneity and massive data. The paper analyzes the security management of mobile storages, proposed practical mobile storage and data security management methods and mechanisms, and illustrates mobile storages integration schemes for single storage device and multiple storages devices and cloud storage. The overall mobile storage and data security policies and methods should be performed urgently.

Abstract: We design a V2V-based fast handoff scheme using IP address passing for VANETs in this thesis. The proposed scheme allows a leaving vehicle in the exit area to pass an IP address which has been identified by the Duplicate Address Detection (DAD) procedure to the vehicles in the entry area directly. In addition, the leaving vehicle in the exit area can also pass an IP address to the vehicles in the middle area if there is no vehicles in the entry area. Therefore, our scheme can reduce the use of DHCP to obtain an IP address. Because DAD results in the largest delay of the whole DHCP procedure, our scheme can thus improve the utilization of IP address, reduce the time of acquiring an IP address, and reduce the whole handoff time.

Abstract: A new protocol for CAN user layer communication based on CAN2.0B which is named Qucan_A is presented, at the same time, combined with the feature of control network, the design ideas and protocol structure have been provided, and the examples of how to use it are also given. (Abstract)Keywords-Field bus; Control network; CAN; User layer communication protocol (keywords)

Abstract: Pub/Sub message exchange pattern (PSMEP) is a flexible and effective message exchange pattern, by which various components in a large-scale distributed system can be linked together organically and interact with each other in a loosely coupled environment. There are two PSMEPs in traditional Pub/Sub model: topic-based pattern & content-based pattern. Topic-based pattern is elegant and efficient, but not flexible to make subscription; while content-based pattern is flexible enough, but is not efficient. This paper proposes a policy-based mixed PSMEP to make up the deficiency of the two patterns, and a simulation in traffic monitoring system introduced in this paper will proof the policy-based pattern is effective.

Abstract: The development of intrusion detection systems in the world are reviewed in this article first. On the basis of in-depth analysis of the characteristics of network attacks and intrusions we aim at to solving the problems mentioned above, the characteristics of survival of the fittest genetic algorithm is used to solve the problem. Second, a detection model based on genetic algorithms is established, and finally the model is simulated. The simulation results show that the model can solve its intrusion detection system, security issues, with a theoretical and practical application.

Abstract: This paper presents RandomBug, a novel real-time path planning algorithm, for an autonomous mobile agent in completely unknown environment. According to this algorithm, all the planned paths are described and stored in the form of vectors. When the agent moves along the planned paths, it only considers the rotation angle and the movement distance in a single direction. The algorithm combines range sensor data with a safety radius to determine the blocking obstacles and calculate the shorter path by choosing the random intermediate points. When there is obstacle blocking in the current path, the intermediate points will be calculated randomly and the planned path will be regenerated by inserting the selected random intermediate points. Simulation results are given to show the effectiveness of the proposed algorithm.

Abstract: The two-phase commit protocol is widely used in distributed database systems to ensure the atomicity of distributed transaction. The traditional two-phase commit protocol fails to solve the blocking problem when the coordinator is out of service. Three-phase non-blocking commit protocol was designed to solve the blocking problem of two phase commit protocol, but it brought heavy communication and log overhead between sites. In todays distributed database systems, due to the growing large number of sites, the failure of single point become more and more often. The traditional commit protocol has become a bottleneck of the system. In this paper, a new non-blocking two-phase commit protocol is proposed to solve the blocking problem. Compared to the traditional three-phase commit protocol, the proposed protocol reduces the log and communication overhead. Theoretical proof has been given to show that the proposed commit protocol is non-blocking and meet the ACID properties under variety of failure conditions.

Abstract: For configuring wireless sensor networks system and node deployment in tea plantation, this paper researched propagation characteristics of 2.4 GHz wireless channel at different directions and heights in perennial tea plants. Received signal strength and packet loss numbers were obtained by field testing measurements at three directions and two heights. The results showed that different heights of sensor nodes in the tea plants determine the wireless channel propagation characteristics. But the impact of propagation directions on wireless signal is weaker. Besides, validation results show that it s best to deploy the sensor nodes antennas on the top of the tea canopy or above of it in the tea plantation. This research can provide technical support for WSN application in tea plantation.