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51.
在计算机网络信息技术成为社会进步助力的同时,网络信息安全也面临着严重的威胁。本文简要分析了影响计算机网络信息安全的主要因素,并就这些问题对网络信息的安全防范进行了探讨。 相似文献
52.
53.
Jakob Nielsen 《International journal of human-computer interaction》2013,29(2):137-147
A group of users in Copenhagen were asked to evaluate how important a number of user interface characteristics were for them. The results show high importance of efficient daily use and of possibilities for exploratory learning while tutorial materials were of less importance. Users also were asked to evaluate four usability aspects of a number of popular programs. Results show that the quality pleasant to work with has the largest impact on evaluations of overall user‐friendliness while users seem able to view usability independently from the number of features in an application. 相似文献
54.
Abstract A growing number of organizations are implementing the ITIL (IT Infrastructure Library) “best practice” framework in an attempt to improve their IT service management processes. However, not all ITIL implementations are successful and some companies have been disappointed with the outcomes. This exploratory research reports on four case studies of “successful” implementations of IT service management using the process-based ITIL V2 framework. Two companies are located in the U.S. and two in Australia. The cases demonstrate a mix of implementation justifications and strategies. Critical success factors (CSFs) suggested in the literature are compared against those attributed to these successful ITIL implementations. Some CSFs, including executive management support, interdepartmental communication and collaboration, use of consultants, training and careful software selection are confirmed. Three new CSFs are identified: creating an ITIL-friendly culture, process as a priority, and customer-focused metrics. Practitioner guidelines, to assist IT managers, who are contemplating adopting ITIL for process improvement and organisational transformation, are also provided together with some challenges encountered and their associated resolutions. 相似文献
55.
苗存霖 《计算机光盘软件与应用》2011,(15)
随着信息产业的高速发展,计算机网络也迅速普及,各部门都利用互联网建立自己的信息系统渗透到我们生活的各个角落。以充分利用各类信息资源。但在连接信息能力、流通能力提高的同时,基于网络连接的安全问题也日益突出。然而,网络自身固有其脆弱性,并且中国的网络信息技术起步较晚,给网络安全带来诸多潜在的威胁。本文针对影响计算机网络系统安全的主要因素,结合实际工作进行分析,并提出相应的对策进行探讨。 相似文献
56.
K. Marti 《Computer Methods in Applied Mechanics and Engineering》2008,198(1):42-51
Problems from plastic analysis are based on the convex, linear or linearised yield/strength condition and the linear equilibrium equation for the stress (state) vector. In practice one has to take into account stochastic variations of several model parameters. Hence, in order to get robust maximum load factors, the structural analysis problem with random parameters must be replaced by an appropriate deterministic substitute problem. A direct approach is proposed based on the primary costs for missing carrying capacity and the recourse costs (e.g. costs for repair, compensation for weakness within the structure, damage, failure, etc.). Based on the mechanical survival conditions of plasticity theory, a quadratic error/loss criterion is developed. The minimum recourse costs can be determined then by solving an optimisation problem having a quadratic objective function and linear constraints. For each vector a(·) of model parameters and each design vector x, one obtains then an explicit representation of the “best” internal load distribution F∗. Moreover, also the expected recourse costs can be determined explicitly. Consequently, an explicit stochastic nonlinear program results for finding a robust maximal load factor μ∗. The analytical properties and possible solution procedures are discussed. 相似文献
57.
相似度量是图像检索的关键,EMD是一种有效的度量距离,但其计算比较复杂,而且赖于基本距离的选择。采用Lloyd聚类算法对图像进行高斯混合建模,并以聚类失真作为基本距离提出了两种近似EMD的方法计算相似度。实验结果验证了该方法的有效性,其检索效率与EMD方接近,而且计算复杂度比EMD方法低,基本距离的选择不敏感。 相似文献
58.
Although there have been a number of studies of the determinant factors of Electronic Data Interchange (EDI) implementation, most studies were carried out in the United States or Europe. The purpose of this study is to identify the determinant factors which affect implementation of EDI systems by Korean companies. Decentralization, EDI standards, technical compatibility, technical support by EDI vendors, education and training and participation of trading partners positively affect the extent of EDI usage. Formalization, technical compatibility, user involvement and participation of trading partners affect EDI integration with internal applications. Top management support and the participation of trading partners promote the extent of EDI operations. This study provides evidence of the effect of important determinant factors such as participation of trading partners and technical compatibility replicating previous EDI studies conducted in that US and Europe. For policy makers ad EDI developers, this study provides insights as to appropriate measures and incentives system designed to encourage EDI and B2B implementation. 相似文献
59.
何伟 《数字社区&智能家居》2009,(7)
将图像进行提升小波变换,分别对高低频采用不同的融合方法,得到融合后图像。并引入信息熵、相关系数和清晰度等性能指标对融合后的图像进行分析。实验结果表明,此提升方法在融合图像质量上优于传统小波变换。 相似文献
60.
以创新扩散理论与文献为依据构建了企业电子商务采纳与应用关键影响因素模型,并以长三角地区企业为主体进行了问卷调查。在利用SPSS对调查结果进行信度分析的基础上,采用结构方程模型对假设模型进行了实证,研究结论有助于企业认清自身所处的环境与条件,了解电子商务技术采纳行为形成的机理,有效管理电子商务技术采纳与应用活动。 相似文献