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991.
通过介绍VB与8QLServer的集成,利用VBK 的远程数据控制与远程数据对象控制实现电子邮件与WQLServer数据库的连接。 相似文献
992.
993.
Surface tensions of the Sn–Ga–In ternary alloy are calculated from the surface tensions of the Sn–Ga, Ga–In and In–Sn sub-binary systems by using geometric models (the Kohler model and the Toop model), and a general solution model (the Chou model). The calculated results are in excellent agreement with the experimental data (except for the Kohler model), assuming an experimental accuracy of ±2.5%. At the same time, the surface tensions of the Sn–Ga–In ternary alloy at 773 K and their sub-binary systems are predicted on the basis of Butler’s equation, in combination with thermodynamic data, and different model parameters β equal to the ratio of the coordination number in the surface phase to that in the bulk phase. Different values of β have almost no influence on the surface tensions. The predicted results agree with the experimental data. Therefore, the resulting iso-surface tension curves for the Sn–Ga–In ternary alloy at 773 K, especially those calculated by using the Toop model, are reasonable. 相似文献
994.
An image rectification scheme and its applications in RST invariant digital image watermarking 总被引:1,自引:1,他引:0
This paper presents an image rectification scheme that can be used by any image watermarking algorithm to provide robustness
against rotation, scaling and translation (RST) transformations. Rotation and scaling transformations in the spatial domain
result in cyclically translational shifts in the log-polar mapping (LPM) of the magnitude of the Fourier transform spectrum
of an image. We cut a small block from the LPM domain as a matching template. A new filtering method is proposed to compute
the cross-correlation between this template and the magnitude of the LPM of the image having undergone RST transformations
to detect the rotation and scaling parameters. We employ the same strategy in the spatial domain to detect the translational
parameters in the spatial domain. The scheme can also be used to detect image flipping. The cost of the templates is low and
the templates can even be compressed. The detection accuracy for rotation, scaling and translation is also presented. We compare
the matching results for the different filters and their performance by the three criteria: signal-to-noise ratio (SNR), peak-to-correlation
energy (PCE), and Horner efficiency. We demonstrate that our phase-only filtering method is the only one that can be used
in the LPM domain. We also introduce three applications for this rectification scheme and give their experimental results.
相似文献
Jiying Zhao (Corresponding author)Email: |
995.
Distributed authorization is an essential issue in computer security. Recent research shows that trust management is a promising
approach for the authorization in distributed environments. There are two key issues for a trust management system: how to
design an expressive high-level policy language and how to solve the compliance-checking problem (Blaze et al. in Proceedings
of the Symposium on Security and Privacy, pp. 164–173, 1996; Proceedings of 2nd International Conference on Financial Cryptography
(FC’98). LNCS, vol.1465, pp. 254–274, 1998), where ordinary logic programming has been used to formalize various distributed
authorization policies (Li et al. in Proceedings of the 2002 IEEE Symposium on Security and Privacy, pp. 114–130, 2002; ACM
Trans. Inf. Syst. Secur. (TISSEC) 6(1):128–171, 2003). In this paper, we employ Answer Set Programming to deal with many complex
issues associated with the distributed authorization along the trust management approach. In particular, we propose a formal
authorization language providing its semantics through Answer Set Programming. Using language , we cannot only express nonmonotonic delegation policies which have not been considered in previous approaches, but also
represent the delegation with depth, separation of duty, and positive and negative authorizations. We also investigate basic
computational properties related to our approach. Through two case studies. we further illustrate the application of our approach
in distributed environments. 相似文献
996.
Yan R Zhang J Yang J Hauptmann AG 《IEEE transactions on pattern analysis and machine intelligence》2006,28(4):578-593
To deal with the problem of insufficient labeled data in video object classification, one solution is to utilize additional pairwise constraints that indicate the relationship between two examples, i.e., whether these examples belong to the same class or not. In this paper, we propose a discriminative learning approach which can incorporate pairwise constraints into a conventional margin-based learning framework. Different from previous work that usually attempts to learn better distance metrics or estimate the underlying data distribution, the proposed approach can directly model the decision boundary and, thus, require fewer model assumptions. Moreover, the proposed approach can handle both labeled data and pairwise constraints in a unified framework. In this work, we investigate two families of pairwise loss functions, namely, convex and nonconvex pairwise loss functions, and then derive three pairwise learning algorithms by plugging in the hinge loss and the logistic loss functions. The proposed learning algorithms were evaluated using a people identification task on two surveillance video data sets. The experiments demonstrated that the proposed pairwise learning algorithms considerably outperform the baseline classifiers using only labeled data and two other pairwise learning algorithms with the same amount of pairwise constraints. 相似文献
997.
本文简单介绍了PROFIBUS和AS-I现场总线的原理并详细说明了它们在汽车生线的应用. 相似文献
998.
PCL5数据压缩原理及应用 总被引:1,自引:0,他引:1
介绍了PCL5命令集,PCL5的四种数据压缩算法的原理,然后以Word文档镜象打印处理为例介绍了PCL5数据压缩方法的应用。 相似文献
999.
WebGIS技术信息查询系统开发及实现 总被引:30,自引:2,他引:28
分析了具有代表性的WebGIS平台MapXtreme系统的原理及特点,给出了系统实现的具体方法及在“九五”国家地方重大攻关项目的应用系统-浙江省综合水利信息系统中的运行实例。 相似文献
1000.
基于PROFIBUS的经济型现场总线控制系统 总被引:4,自引:0,他引:4
介绍了PROFIBUS的体系结构、通信协议及基于PROFIBUS、PC、PLC实现的现场总线控制系统。本文郑重讨论PROFIBUS-FMS的特性、功能及其应用。 相似文献