Coverage-enhancing approach in multimedia directional sensor networks for smart transportation

Smart transportation has a significantly impact on city management and city planning, which has received extensive attentions from academic and industrial communities. Different from omni-directional sensing system, as a directional sensing system, the multimedia-directional sensor network holds the special coverage scheme, which is usually used for smart cities, smart transportation, and harsh environment surveillance, for instance, nuclear-pollution regions where are inhospitable for people. This paper advances Virtual Stream Artificial Fish-swarm based Coverage-Enhancing Algorithm (VSAFCEA) as a coverage-enhancing means in multimedia directional sensor networks. Firstly, a concept of virtual streams, based on traditional artificial fish-swarm algorithm, is proposed. Then, the traditional behaviors of fishes in artificial fish-swarm algorithm are modified and expanded with several new behaviors. Finally, the presented VSAFCEA is adopted for coverage-enhancing issue in the situation of directional sensor networks with rotational direction-adjustable model. With a sequence of steps of artificial fishes in virtual stream, the presented VSAFCEA can figure out the approximation to the highest area coverage rate. Based on comparison of these simulation results (results of presented VSAFCEA and that of other typical coverage-enhancing ways in directional sensor networks), the conclusion can be drawn that VSAFCEA could attain higher area coverage rate of directional sensor networks with fewer iterative computing times.

     

Corpus based part-of-speech tagging

In natural language processing, a crucial subsystem in a wide range of applications is a part-of-speech (POS) tagger, which labels (or classifies) unannotated words of natural language with POS labels corresponding to categories such as noun, verb or adjective. Mainstream approaches are generally corpus-based: a POS tagger learns from a corpus of pre-annotated data how to correctly tag unlabeled data. Presented here is a brief state-of-the-art account on POS tagging. POS tagging approaches make use of labeled corpus to train computational trained models. Several typical models of three kings of tagging are introduced in this article: rule-based tagging, statistical approaches and evolution algorithms. The advantages and the pitfalls of each typical tagging are discussed and analyzed. Some rule-based and stochastic methods have been successfully achieved accuracies of 93–96 %, while that of some evolution algorithms are about 96–97 %.     

Synchronization of Instantaneous Coupled Harmonic Oscillators With Communication and Input Delays

This paper investigates the synchronization issue of instantaneous coupled harmonic oscillators with communication and input delays. A distributed synchronization algorithm is proposed for such oscillator systems, and some general algebraic criteria on exponential convergence are established for the algorithm. The main contributions of the present investigations include: (i) the directed network topology is first considered in the case of instantaneous interaction; (ii) both the time‐varying communication and input delays are simultaneously addressed; (iii) the effects of communication and input delays on synchronization performance of coupled harmonic oscillators are discussed. It is shown the communication delays have a more important impact than the input delays on determining synchronization dynamics of coupled harmonic oscillators. Explicitly, in absence of communication delays, coupled harmonic oscillators can achieve synchronization oscillatory motion, whereas, so long as communication delays are nonzero at infinite multiple impulsive times, its synchronization (or consensus) state is zero. Finally, numerical examples demonstrate the obtained theoretical results.     

基于C#的DES加密算法的应用

信息安全问题伴随着信息技术和产业的急速发展越来越突出,为了防止信息的泄漏,对信息的加密保护迫在眉睫.本文运用C#语言对DES这种复杂度高、保护性强的算法进行了算法实现,并在数据库信息的加密中加以应用.     

校园迎新报到系统的网络供应解决方案——以扬州工业职业技术学院为例

校园迎新报到系统为数字化迎新提供了可能,而数字化迎新又以稳定的网络保障为后盾,如何为报到系统提供稳定而安全的网络保障,成为部分高职院校面临的一个问题。本文以扬州工业职业技术学院为例,简单探析了几种网络保障的解决方案。     

基于精确流量控制的局域网网关出口管理策略

局域网应用越来越广泛,鉴于网络宽带的有限性,提出了基于精确流量控制的局域网网关出口管理策略,网络出口管理的优化控制得以实现,有效改善了局域网络拥塞问题.     

计算机网络设计中关系数据库技术的应用

随着信息化技术的发展,计算机网络设计逐渐兴起并讯速发展。在计算机网络设计过程中,其工序相当复杂,因此需要建立与其相关的数据库保障计算机网络设计。关系数据库技术根据数据库中数据的相关性储存、调度数据,从而使其更好地服务于计算机网络设计。本文简要论述了关系数据库的概况、关系数据库在计算机网络设计中的辅助功能,分析了关系数据库技术在计算机网络设计中的基本原理并探讨了它在计算机网络设计中的优势。     

Performance analysis on Lv distribution and its applications

A new signal analysis method, known as Lv distribution (LVD), has been reported recently to provide improved estimation accuracy of centroid frequency and chirp rate. In this paper, performances of the LVD on signal concentration, detection, representation errors and computational complexity are discussed and compared with polynomial Fourier transform (PFT) and fractional Fourier transform (FrFT). Based on the results of our theoretical analysis and Monte Carlo simulations, it is shown that the LVD achieves desirable performance improvement compared with those achieved by other methods. By using the accurate estimation of chirp rate provided by the LVD, the performance of local polynomial periodogram (LPP) is investigated. Comparisons with other time–frequency representations, such as the inverse LVD (ILVD) and the PFT-based LPP, are made on signal concentration in the time–frequency domain.     

SQL Server的数据库加密技术的研究与实现

数据库加密就是对数据库的文件或数据进行加密,数据加密后以密文方式存储,即使被窃取、被拷贝,机密数据也不会被敌对方获取。本文介绍了SQL Server数据库常见的安全问题和数据库加密技术,提出了一种对于数据库字段的加密技术。