基于物联网技术的矿井资产管理系统中的设计与实现

文中针对公司资产存在的形式多种多样,公司管理人员年底清查资产需要浪费大量宝贵的时间和人力物力,且容易遗漏或重复,实物很难与账面相符的管理情况,设计了一个基于物联网与FRID技术相结合的资产管理系统,在介绍了物联网技术与FRID技术后,详细介绍了该系统的整体架构设计,资产编码设计、RFID标签设计,资产管理系统设计。通过对该系统的实际应用表明,该系统实现了资产系统化、信息化、网络化的管理。对于合理配置和利用资产,降低投入成本,增加投入产出效益,提高管理水平和效率等方面上有着重大的意义。实现了资产管理的信息共享。     

Random waypoint model in n-dimensional space

The random waypoint model (RWP) is one of the most widely used mobility models in performance analysis of mobile wireless networks. In this paper we extend the previous work by deriving an analytical formula for the stationary distribution of a node moving according to a RWP model in n-dimensional space.     

自组网体系结构研究

CSCW系统目标是允许用户在任何地点任何时间可以方便地进行群体间的协同工作.目前大多数的CSCW用户都需要依靠现有的网络基础设施.自组网是一组带有无线收发装置的移动节点组成的一个多跳的临时性的自治系统.在这种环境中,由于节点无线通信覆盖范围的有限性,需要借助其他中间节点进行分组转发到达信宿.他可以在没有可用的网络基础设施的情况下提供一种通信支撑环境,从而拓宽了CSCW的应用环境.本文描述了自组网的概念和特点,并提出了自组网的体系结构.     

联通DWDM省干线组网方案探讨

文章首先分析了某联通省级干线传输网的现状及不足；接着在简要介绍DWDM的技术优势后，提出并详细描述了采用DWDM技术改造现有网络的设计方案；最后讨论了该方案在实现联通网络资源优化、配置合理和网络安全保障等方面的优势及发展远景．     

Stimulating Cooperation in Self-Organizing Mobile Ad Hoc Networks

In military and rescue applications of mobile ad hoc networks, all the nodes belong to the same authority; therefore, they are motivated to cooperate in order to support the basic functions of the network. In this paper, we consider the case when each node is its own authority and tries to maximize the benefits it gets from the network. More precisely, we assume that the nodes are not willing to forward packets for the benefit of other nodes. This problem may arise in civilian applications of mobile ad hoc networks. In order to stimulate the nodes for packet forwarding, we propose a simple mechanism based on a counter in each node. We study the behavior of the proposed mechanism analytically and by means of simulations, and detail the way in which it could be protected against misuse.     

tss与MD110联网调试中话路“吊死”问题的分析处理

本文以ｔｓｓ和ＭＤ１１０联网调试中主波叫通话状态下同时挂机时话路出现“吊死”９０ｓ的现象为中心，分析了信令配合过程及产生问题的原因，介绍了解决的办法，提出了两点建议。     

Selective lumping finite element method for nearshore current

A finite element method for the analysis of nearshore current, which is one of the principal currents in coastal seas, is presented in this paper. Because the nearshore current is induced by the variable distribution of the surface waves, it is necessary to analyse two main characteristics of the wave, i.e. direction and height. The current can be computed using the resulting wave characteristics. The present method makes it possible to employ procedures for which the same methods of solution are applicable for all basic equations of wave direction, height and current flow. The linear interpolation function is used for the discretization of spatial variables and a selective lumping two step explicit scheme is employed for the numerical integration in time. The numerical solutions obtained are compared with analytical, experimental and observed ones. From these comparative studies, it is concluded that the present finite element method provide a useful tool for the analysis of nearshore current.     

General considerations of numerical stability and accuracy in inviscid,compressible flow calculations employing primitive variables

The numerical stability of a number of computation schemes currently used for three-dimensional, inviscid, compressible flow is analysed using one-dimensional Fourier analysis. Whereas Reference 1 analysed schemes which were modified to render them amenable to simple analysis, the present work analyses the stability of schemes as actually used by Highton,³ Ahrabian,¹ Denton² and Spalding.⁶ The use of current values of the variables as they become available is shown to bring a general improvement to stability margin. The manner of damping introduced by the time marching formulation is shown to be deleterious to modifications which reduce truncation error. Staggered grid schemes can be formulated to second order accuracy with better stability margin than the corresponding first order scheme. While unstaggered grid schemes can be formulated to second order error and remain stable, their stability margin becomes very small. Agreement of the theory with numerical experiments continues to be of a high order for both one and three-dimensional disturbances.     

Chirp Control of an Electroabsorption Modulator to be used for Regeneration and Wavelength Conversion at 40 Gbit/s in All-Optical Networking

Chirp control to produce low or negative values of chirp at the output of an electroabsorption modulator (EAM) is an important mechanism for reducing the signal degradation due to chromatic dispersion in high-speed transmission over standard single-mode fibre. An analytical model for the chirp performance of an EAM capable of optical regeneration and simultaneous wavelength conversion operating at 40 Gbit/s is derived. A chirp control approach is identified using this model by exploring the tradeoff between the α-parameter describing the chirp factor (based on the nonlinear absorption coefficients) and bias voltage requirements of an EAM. In particular, an optimum range of bias voltage is determined to ensure reduced chirp operation when a two-tone signal (i.e., comprised of bias and modulating voltages) is applied to the EAM. It is also demonstrated for large signal operation at 40 Gbit/s that the optimum range of reverse bias voltage is between 0 and 2 V to obtain low values for the chirp factor (between +1 and −2) in order to facilitate the necessary chirp control in all-optical networking. In addition, it is identified that at 40 Gbit/s higher positive values of the second- and third- order nonlinear coefficients of chirp must be avoided when operating at reverse bias voltages less than 1 V.