The expressive power of regular expressions has been often adopted in network intrusion detection systems, virus scanners, and spam filtering applications. However in the CPU based systems, pattern matching is one of the most computation intensive parts. In this paper, we present the design, implementation and evaluation of a regular expression string matching processing unit (SMPU). This special purpose processor is a parallel and pipelined architecture which can deal with the regular expression semantics. Two hardware stacks are implemented in SMPU to support fast branches when the non-matching occurs. Our implementation processes four characters per clock cycle (maximum performance of state of the art solutions) and occupies only O(n) memory (where n is the length of the regular expression) via synthesizing the verilog description and analyzing area/time constraints, SMPU can achieve 200–400 times speedup over traditional CPU implementations and up to 7.9Gbps in processing throughput. Besides it outperforms the counterparts greatly as the complexity of regular expressions increases.

Conventional MAC protocols for wireless sensor network perform poorly when faced with a delay-tolerant mobile network environment. Characterized by a highly dynamic and sparse topology, poor network connectivity as well as data delay-tolerance, delay-tolerant mobile sensor networks exacerbate the severe power constraints and memory limitations of nodes. This paper proposes an energy-efficient MAC protocol using dynamic queue management (EQ-MAC) for power saving and data queue management. Via data transfers initiated by the target sink and the use of a dynamic queue management strategy based on priority, EQ-MAC effectively avoids untargeted transfers, increases the chance of successful data transmission, and makes useful data reach the target terminal in a timely manner. Experimental results show that EQ-MAC has high energy efficiency in comparison with a conventional MAC protocol. It also achieves a 46% decrease in packet drop probability, 79% increase in system throughput, and 25% decrease in mean packet delay.

The property of community structure is very important in social network analysis and has attracted particular attention of many researchers in this field. Recent years have seen the development of many community detection algorithms which can be mainly classified into two kinds: graph partition in computer science and hierarchical clustering in sociology. The vast majority of these methods, however, are computationally demanding, which largely limit their application to small, at most moderate scale networks. Here we present a very Simple Agglomerative Strategy (SAS) to detect community structure based on closeness among vertices, which not only yields excellent results but also has very low time complexity. The algorithm is tested on several real-world networks and proved to be high efficient and effective in community finding. The running time of the whole algorithm is only O(m (k) over bar) for sparse networks, where (k) over bar is the mean vertex degree and m is the number of edges in the network.

This paper analyzes the shortcomings of existing meter reading systems,proposes a wireless centralized meter reading system based on short distance wireless communication and 3G.The system combines the short distance wireless communication and 3G technology together with the data's collection and transmission through a wireless manner.The collected data of meter are transmitted through the 3G network to the billing department of the data management center.When compared with existing meter reading systems,this system has a more flexible layout,larger coverage,lower power consumption,higher real-time features,less interference and gets better results in practical application.

This paper describes a header compression scheme for the IPv6 stack in wireless sensor networks,including the compression of IPv6 header,extension headers and UDP header.This scheme,which is easy to implement,can reduce the time for packet transmission in WSN greatly,thus it can reduce energy cost and prolong the lifetime of the nodes.

Aiming at the characteristics of node operating system and its demands for real-time performance,security and concurrency,this paper proposes a new kernel schedule algorithm for real-time system.By combining task priority dispatching with time slot cycling,it boosts the response speed of the processor,and improves the real-time characteristics of the system.The strategy is implemented on μCOS-Ⅱ,and the modified kernel is applied to the wireless acquisition system,whose result proves that the algorithm reduces response time of the system and improves its efficiency.

Disease detection, response and information communication are key components to the Alberta Veterinary Surveillance Network (AVSN) [1]. A strategy for data collation and information dissemination is vital to the success of AVSN.

The disclosure of the number of votes can compromise the voters' anonymity of the electronic voting.Aiming at this problem,this paper defines anonymity by using the uncertainty of the voting choices and measures the anonymity of the whole voting system by entropy.It compares the anonymity after the release of the voting results with that before releasing the voting results.Analysis result shows that the smaller the voting scale is,the more the voters' anonymity loses.In the design of small-scale electronic-voting scheme,releasing the winner instead of the number of votes that candidates gained decreases the loss of anonymity.

According to the application requirement in sports training,a new athletic training system is designed by taking advantage of wireless sensor network technologies.It is composed of the embedded data gathering terminal and the database server.Designed with sensor nodes and base stations,the hardware can examine the real-time acquisition of the movement parameters of athletes.Meanwhile,nodes,based station controlling and data management software is designed,realizing its functions of data receiving,data storing and analyzing.Through system experiment,the result indicates that athletic training system meets the sports training need and provide an effective research tool for making scientific training program.

An improvement in PRoPHET protocol is proposed in the paper in which an end-to-end connecton in the temporary cluster and the rouing adaptation which the less emergent messages in the congestion node are transferred to some other node in the temporary cluster then the more emergent messages to the congestion node when the DTN congestion occurs in the network is utilized besides the basic utility method. The performance is analyzed and compared to the PRoPHET protocol in the paper.As the simulation results show,the performance is improved in the metrics of the ratio of the success delivery message and average message delivery delay.

This paper addresses the problem of scheduling mobile sink nodes among different candidate locations, thus to maximize network lifetime in wireless sensor network. A novel concept named placement pattern (PP) is proposed to bound the traffic patterns with candidate locations, which could significantly decrease the number of elements to be scheduled. Then this sink node placement problem is formulated by using linear programming techniques based on PP concept. Finally, an optimal placement schedule is constructed in the light of LP solution. Experiment results indicate that the proposed scheme is effective, and even sink node with limited mobility would greatly enhance the lifetime of wireless sensor network.

In wireless sensor networks routing protocol using mobile terminals(ferry node) has been improved in the paper.By analyzing the movement of ferry node,we propose the double ferry node using reverse movement,combined with unexpected situations adaptive processing program;and we prove reverse-movement to improve the ferry carrying capacity of the node,reducing the information delay,and thus improve the network transmission capacity by theoretical analysis;the simulation results also prove this point.

无线局域网安全涉及因素众多,传统的基于入侵检测的被动安全分析系统,体系结构复杂、检测精度低.基于协议分析理论的主动安全分析方法,测试目标明确、可预测性强.脚本语言效率高,灵活性、可扩展性强,易于配置.本文有机地结合了两者的特点,设计出了一种基于Tcl脚本的WLAN主动安全分析系统,系统采用模块化设计,层次结构清晰,具备测试目的明确,可预测性强,系统配置灵活.针对安全实例,构造并执行了测试脚本,结果表明,系统能有效检测出无线局域网的安全问题.

For Delay-Tolerant Mobile Sensor Networks with highly dynamic and sparse topology, a queue management MAC protocol (Q-MAC) is proposed in this paper. Via the scheme of data transfers initiated by the targeted sinker and dynamic queue management strategy, Q-MAC provides better network performance. Furthermore experimental results show that Q-MAC reaches to 46% decreases in packet drop probability, 79% increase in system throughput, and 25% decrease in the mean packet delay.

Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters.

This paper introduces an input method in detail based on embedded Linux and Qtopia matrix keyboard.By reimplementing the Qt event filter, combined with signal and slot mechanism to deal with the use of two-tier status, it is possible to use the definition of the effective input to simplify the input process, reduce the number of pressing button, and enhance the efficiency of input.At the same time, with the use of Qtopia graphical display, the input interface is clearer and more applicable to the embedded device.

Being different from other networks, the load and direction of data traffic for wireless sensor networks are rather predictable. The relationships between nodes are cooperative rather than competitive. These features allow the design approach of a protocol stack to be able to use the cross-layer interactive way instead of a hierarchical structure. The proposed cross-layer protocol CLWSN optimizes the channel allocation in the MAC layer Using the information from the routing tables, reduces the conflicting set, and improves the throughput. Simulations revealed that it outperforms SMAC and MINA in terms of delay and energy consumption.

A cross-layer energy-efficient protocol architecture(TEPA) was proposed for wireless sensor networks(WSN).A cross-layer design perspective was adopted in TEPA for high efficiency,where direct interactions between the network layer and the medium access control(MAC) layer were exploited.In TEPA,the TDMA schedule was designed with the differential evolution(DE) algorithm depending on not only the neighborhood information but also the routing information.By limiting contention between adjacent branches and accelerating transmission in individual branches of the data gathering tree,TEPA was able to reduce the latency,as well as optimizes the energy utilization of the network.Different from the previous schemes,TEPA doesn't try to minimize the schedule length while a suitable schedule length is found based on the tradeoff on throughput and delay under different traffic loads.Simulation results show that TEPA enhances performance in terms of delay and energy consumption.

Delay tolerant networks may become unexpectedly partitioned due to node mobility or variation in signal strength. However, most widely used models in some relative works are generally very simplistic. In order to exploit intelligent forwarding algorithms, a novel nodal mobile model of delay tolerant networks is presented to map reality with more accuracy. And several approaches are introduced to analyze the network structure, such as n-cliques, n-clans, degree, closeness and betweenness. Our research results showed that the centralizations became smaller when the wireless connections were concerned. It meant that quite a number of nodes became potential relays because of the new structure of networks.

The data fusing ability of cluster head is affected by the correlation of sensed data from different nodes in Wireless Sensor Networks, which are data centered. This paper analyses the influence of regional data correlation on energy efficiency of clustering protocol, and then proposes a data aware clustering for data gathering (DACDG). DACDG uses residual energy and the correction of sensed data from neighbors to construct clusters, and adopts the way of iterative computing to elect cluster head. Compared with existing protocols, simulation results show that DACDG achieves its goals of consuming less energy, equalizing the energy consumption of all the nodes, as well as extending the network lifetime outstandingly.