基于压缩感知的无线传感器网络的数据编码

近年来,基于压缩感知的无线传感器网络数据编码的研究取得了一定的进展,但大部分研究是基于"单跳"的传输模型或者没有考虑网络内节点之间的合作。本文提出了一种基于压缩感知和分簇的传感器网络数据编码方法。首先,节点根据自己的编号伪随机的产生一个M维的列向量,把感知的数据xi投影到此向量上,然后把自己的编号和投影的数据一同传输给簇头。簇头把收到的数据进行求和,并且把计算后的结果传送给下一个簇头,直到sink节点。通过仿真实验和理论分析,验证了本文提出的方法比传统的方法能更好地减少网络内数据传输量。     

工作流技术在ASP公共服务平台中的应用研究*

根据项目特点,建立了适合ASP平台的基于协调理论和反馈机制的扩展活动网络模型,采用XML模式的XPDL规范实现过程定义;然后通过DOM解析XML数据文档和J2EE的技术支持实现了系统的轻量级工作流引擎.详细介绍了系统实现中解决的两个关键问题:事务型操作的处理和并发控制,并提出了基于优先级的锁绑定机制.     

基于DSP+CPLD的车牌实时识别系统的设计

传统的基于微机的车牌识别系统的方案,使得评价识别效果的识别速率和识别成功率两个重要指标相互冲突.为了解决这个问题,很多文章提出了改进算法来调和识别算法的计算量和识别的成功率,但却没有考虑识别系统的成本问题.提出了一个基于DSP CPLD的硬件识别平台,可以大大提高各种识别算法的适应性和降低系统成本.     

Improved migration for mobile computing in distributed networks

A mobile ad hoc network (MANET) is a special type of wireless network in which a collection of mobile nodes with wireless network interfaces may form a temporary network, without the aids of any fixed infrastructure. Security has become a hot research topic in mobile ad hoc networks. In 1998, Volker and Mehrdad proposed a tree-based key management and access control scheme for the mobile agents to manage rights to access its own resources for the visited mobile nodes. Latter, Huang et al. showed that Volker and Mehrdad's scheme needs a large amount of storage and costs for managing and storing secret keys. Huang et al. further proposed a new and efficient scheme based on the elliptic curve cryptosystems to reduce costs and gain better efficiency. However, there is a security leak inherent in Huang et al.'s scheme that the malicious node can overstep his authority to access unauthorized information. This paper will propose a secure, robust, and efficient hierarchical key management scheme for MANETs. Some practical issues and solutions about dynamic key management are also considered and proposed. As compared with Huang et al.'s scheme, our proposed scheme can provide better security assurance, while requiring smaller key-size, lower computational complexities, and constant key management costs which is independent on the number of the confidential files and the visited nodes.     

Enterprise security pattern: A model-driven architecture instance

To secure their information assets, organizations should seek support from enterprise security architectures. Security patterns are a good way to build and test new security mechanisms, but they have some limitations related to their usability. In previous work, we defined a new type of security pattern called Enterprise Security Pattern. The main objective of these patterns is to provide an instance of model-driven architecture, which offers a solution to recurring problems that have to do with information systems security. In recent years, the hiring of Software as a Service (SaaS) from cloud providers has become very popular. There seem to be many advantages of using these services, but organizations need to be aware of a variety of threats, as well as being prepared to handle them. In another work undertaken previously, we defined an enterprise security pattern called Secure Software as a Service (Secure SaaS), which the organizations could apply to protect their information assets when using SaaS. In this paper, we present different instances of the solution models of the enterprise security pattern Secure SaaS, aiming to verify the risks that an organization would assume if each of the instances were deployed. With this approach, we intend to show how the design decisions adopted when performing the transformations between the solution models can have a direct impact on the security provided by the pattern.     

PPREM: Privacy Preserving REvocation Mechanism for Vehicular Ad Hoc Networks

One of the critical security issues of Vehicular Ad Hoc Networks (VANETs) is the revocation of misbehaving vehicles. While essential, revocation checking can leak potentially sensitive information. Road Side Units (RSUs) receiving the certificate status queries could infer the identity of the vehicles posing the query. An important loss of privacy results from the RSUs ability to tie the checking vehicle with the query's target. We propose a Privacy Preserving Revocation mechanism (PPREM) based on a universal one-way accumulator. PPREM provides explicit, concise, authenticated and unforgeable information about the revocation status of each certificate while preserving the users' privacy.     

A standard for developing secure mobile applications

The abundance of mobile software applications (apps) has created a security challenge. These apps are widely available across all platforms for little to no cost and are often created by small companies and less-experienced programmers. The lack of development standards and best practices exposes the mobile device to potential attacks. This article explores not only the practices that should be adopted by developers of all apps, but also those practices the enterprise user should demand of any app that resides on a mobile device that is employed for both business and private uses.     

Tabu-based GIS for solving the vehicle routing problem

Besides being a hard combinatorial problem, the VRP is also a spatial problem. Hence, effective decision making in this field strongly requires the integration of GIS and optimization systems (GIS-O). This article integrates GIS and optimization tools for solving the vehicle routing problem with loading and distance requirements (DCVRP). A general outline of the multi-step integration is pointed out showing the interaction of the GIS and the spatial optimization according to the loose coupling strategy. The computational performance of the TS-VRP algorithm for the DCVRP turned out to be quite efficient on both computation time and solution quality. The Tunisian case study well illustrates the incentive behind using such a spatial decision support system that allows the management of the problem from the data acquisition to the visualization of possible simulation scenarios in a more realistic way.     

A survey on nature-inspired optimization algorithms with fuzzy logic for dynamic parameter adaptation

Metaheuristic optimization algorithms have become a popular choice for solving complex problems which are otherwise difficult to solve by traditional methods. However, these methods have the problem of the parameter adaptation and many researchers have proposed modifications using fuzzy logic to solve this problem and obtain better results than the original methods. In this study a comprehensive review is made of the optimization techniques in which fuzzy logic is used to dynamically adapt some important parameters in these methods. In this paper, the survey mainly covers the optimization methods of Particle Swarm Optimization (PSO), Gravitational Search Algorithm (GSA), and Ant Colony Optimization (ACO), which in the last years have been used with fuzzy logic to improve the performance of the optimization methods.