高校档案数字化实践中的思考

档案数字化是信息时代对于档案工作的新要求,推进档案数字化建设也是高校信息化工程中的一项基础性工作。档案数字化工作给予了档案人新的使命和机遇,然而在实际工作中也存在很多问题和困难。本文就高校档案数字化实践中存在的若干问题以及我们的思考探索做了阐述。     

基础软件技术的发展趋势

从分析基础软件的基本概念和特性出发,对基础软件的内容、需求、技术、产品等方面进行了系统论述。探讨了现有的主流开发技术及未来的发展趋势。通过分析现有部分国产软件系统在一些典型领域的应用,揭示我国基础软件发展的现状和难题,为现有国产基础软件产业的发展提供决策参考。     

ARP病毒的分析与防护

现代化的办公系统往往都离不开对电脑的使用,企业和部门电脑运行的稳定尤为重要,由于人们为对电脑的使用不当,或是信息管理部门的管理疏忽,使我们的网络经常受到电脑病毒的干扰,特别是常见的ARP病毒,比如聚生网管、P2P终结者、网络执法官、网络剪刀手、局域网终结者等。ARP病毒通常表现为网络传播快,感染终端定位困难等特点,一旦感染就导致大面积的计算机终端无法进行网络访问     

浅谈政府公文交换系统的发展

在社会信息化的不断推进过程中,各级政府的办公自动化需求也在不断升级,公文交换系统多样化且技术更新加速,随着改革的深入和我国加入WTO,公文交换系统的建设已经成为当前我国信息化建设的首要任务.     

基于SIP协议的VoIP中的威胁、风险和控制

IP语音技术(VoIP)的来临和推动有极大改变电信面貌的潜力。然而,作为一个相对较新的技术,VoIP仍然面临着来自技术和社会的各种安全困扰。在本文中,提出了基于SIP协议的VoIP技术中存在的主要威胁和弱点。此外,将讨论一些应该在企业VoIP系统中实施的安全规定、政策和健全做法。     

基于Web_CORBA信息家电家庭网关的设计与实现

随着各种信息家电的出现及网络技术的发展,家电控制需要一个便捷有效的平台。本文提出了Web_CORBA家庭网关的设计构想,给出了信息家电的接口定义,采用CORBA-CGI方式最终实现了Internet远程控制,并以信息家电冰箱为例给出了具体的设计过程。     

Image categorization: Graph edit distance+edge direction histogram

This paper presents a novel algorithm for computing graph edit distance (GED) in image categorization. This algorithm is purely structural, i.e., it needs only connectivity structure of the graph and does not draw on node or edge attributes. There are two major contributions: (1) Introducing edge direction histogram (EDH) to characterize shape features of images. It is shown that GED can be employed as distance of EDHs. This algorithm is completely independent on cost function which is difficult to be defined exactly. (2) Computing distance of EDHs with earth mover distance (EMD) which takes neighborhood bins into account so as to compute distance of EDHs correctly. A set of experiments demonstrate that the newly presented algorithm is available for classifying and clustering images and is immune to the planar rotation of images. Compared with GED from spectral seriation, our algorithm can capture the structure change of graphs better and consume 12.79% time used by the former one. The average classification rate is 5% and average clustering rate is 25% higher than the spectral seriation method.     

基于模糊Lyapunov函数方法的模糊广义系统H∞控制

研究一类T-S模糊广义系统的容许性条件和H∞控制问题. 首先将原系统表示成增广系统, 进而基于新的模糊Lyapunov函数和模糊控制器得到容许性条件. 所得开环容许条件不要求子系统是容许的; 闭环容许条件中不含有控制输入矩阵与控制增益矩阵的乘积项. 对于H∞控制问题, 利用隶属度函数的性质对H∞控制条件进行了放宽, 并得到了改进的严格线性矩阵不等式(LMI)形式的H∞控制条件. 数值算例表明所得结论较已有文献具有较小的保守性.     

Efficient embedded wavelet codec based on list structure

A new efficient image codec called embedded wavelet coding based on list structure (EWCBL) is proposed in this paper. By combining the techniques of morphological representation and quadtree partitioning, EWCBL effectively exploits both within-subband clustering and cross-subband similarity of wavelet coefficients. Based on the list structure, a fine fractional bit-plane coding is employed to achieve excellent rate-distortion performance. The patterned morphological dilation is introduced to greatly reduce the redundant test operations. Experimental results show that the proposed EWCBL outperforms state-of-the-art embedded codecs for both lossy and lossless compression. Moreover, the good performance and features of embeddedness and scalability are achieved with relatively low complexity.     

Thermodynamic description of the Mg–Eu binary system

Thermodynamic assessment of the Mg–Eu binary system has been carried out by combining first-principles calculations and Miedema’s theory with CALPHAD method. Firstly, the mixing enthalpy of the liquid alloys was calculated by using Miedema’s theory, and formation enthalpies of the intermetallic compounds were calculated by using the projector augmented-wave (PAW) method within the generalized gradient approximation (GGA). Subsequently, the liquid phase was described employing a simple substitutional model, of which the excess Gibbs energy was formulated with a Redlich-Kister expression. And the solubility of Eu in HCP_(Mg) and Mg in BCC_(Eu) were neglected. While the intermetallic compounds Mg₁₇Eu₂, Mg₅Eu, Mg₄Eu, Mg₂Eu and MgEu, were treated as stoichiometric compounds. Consequently, a set of self-consistent thermodynamic parameters for all stable phases in the Mg–Eu binary system were obtained, which can reproduce most of the thermodynamic and phase boundary data.