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991.
Record linkage aims at finding the matching records from two or multiple different databases. Many approximate string matching methods in privacy-preserving record linkage have been presented. In this paper, we study the problem of secure record linkage between two data files in the two-party computation setting. We note that two records are linked when all the Hamming distances between their attributes are smaller than some fixed thresholds. We firstly construct two efficient secure protocols for computing the powers of an encrypted value and implementing zero test on an encrypted value, then present an efficient protocol within constant rounds for computing the Hamming distance based record linkage in the presence of malicious adversaries by transferring these two protocols. We also discuss the extension of our protocol for settling the Levenshtein distance based record linkage problem.  相似文献   
992.
Wireless sensor networks, which are widely used in military, industrial and transportation fields, are vulnerable to various kinds of attacks, since they are mostly deployed in a relatively open environment. Based on the evolutionary game theory, this paper proposes a proactive defense model for wireless sensor networks, in which we emphasize that the node has a limited ability to learn the evolution of rationality from different attack strategies of the attacker, and can dynamically adjust their strategies to achieve the most effective defense. Following this approach, the cost (e.g., energy consumption and wastage of machinery) has been greatly saved and the life cycle of the nodes has been extended as well. By employing the proposed model, the whole wireless sensor network can be implemented in an effective way.  相似文献   
993.
A new synthesis of 4- and 7-carbon-substituted indoles is described. The overall sequence involves the addition of a nitrile oxide to 1 carboethoxy-2-(or 3-) allylpyrrole, hydrogenation of the intermediate isoxazoline to β-hydroxy ketone and cyclization of the ketol using magnesium or zinc triflate to the substituted indole. This new indole-forming strategy can also accommodate the introduction of oxygen functionality into the indole 6-position. Possible mechanistic aspects of the reaction are detailed.  相似文献   
994.
Although perceived value has long been recognised as an influential means of affecting continuance intention in information systems (IS), little attention has been devoted to explore its antecedents, which constitutes an important research issue. This study, building on prior literature on continued usage in IS as well as the resource-based view, proposed a model to address this gap. Our model suggests that perceived value, a major driving force for members’ satisfaction and continuance intention, is affected by four kinds of resources embedded in virtual communities, which are relationship resources, technology infrastructure, knowledge resources and human resources. To provide additional insights on the pivotal role of perceived value, we also postulate that experience moderates the link between perceived value and its antecedents. Data collected from 235 members of a professional virtual community provide strong support for the research model. It was found that perceived value exerts a great effect on both satisfaction and continuance intention. In addition, when different levels of experience are taken into consideration, relationship resources, knowledge resources and human resources were found to be more salient to high-experience members, whereas technology infrastructure was found to be more salient to low-experience members. Finally, this study discusses the implications of these findings and offers direction for future research.  相似文献   
995.
羧甲基淀粉的应用与合成   总被引:6,自引:0,他引:6  
刘跃平  哈成勇 《化学世界》2003,44(7):388-390,392
综述了羧甲基淀粉的发展、合成方法、合成过程中的影响因素以及应用现状。羧甲基淀粉的合成主要分三种类型 :干法、半干法、湿法。综合了反应过程中的影响因素 ,例如醚化剂和催化剂的影响 ,反应时间和温度的关系 ,溶剂、设备对反应的影响 ,以及在食品、医药、钻井、纺织、日化工业中的应用前景  相似文献   
996.
Summary: A new technique, ultrasonically initiated in situ emulsion polymerization, was employed to prepare intercalated polystyrene/Na+‐MMT nanocomposites. FTIR, XRD, and TEM results confirm that the hydrophobic PS can easily intercalate into the galleries of hydrophilic montmorillonite via ultrasonically initiated in situ emulsion polymerization, taking advantages of the multi‐effects of ultrasonic irradiation, such as dispersion, pulverization, activation, and initiation. Properly reducing SDS concentration is beneficial to widen the d‐spacing between clay layers. However, the Na+‐MMT amount has little effect on the d‐spacing of nanocomposites. The glass transition temperature of nanocomposites increased as the percentage of clay increased, although the average molecular weight of PS decreased, and the decomposition temperature of the 1obtained nanocomposites moves to higher temperature.

TEM of PS/Na+‐MMT nanocomposite prepared by ultrasonically initiated in situ emulsion polymerization.  相似文献   

997.
In this paper, we propose a new continuous self‐collision detection (CSCD) method for a deformable surface that interacts with a simple solid model. The method is developed based on the radial‐view‐based culling method. Our method is suitable for the deformable surface that has large contact region with the solid model. The deformable surface may consist of small round‐shaped holes. At the pre‐processing stage, the holes of the deformable surface are filled with ghost triangles so as to make the mesh of the deformable surface watertight. An observer primitive (i.e. a point or a line segment) is computed so that it lies inside the solid model. At the runtime stage, the orientations of triangles with respect to the observer primitive are evaluated. The collision status of the deformable surface is then determined. We evaluated our method for several animations including virtual garments. Experimental results show that our method improves the process of CSCD.  相似文献   
998.
介绍了气体膜分离原理;提出了理想膜过程的新概念;归纳了气体膜分离装置的运行特点;比较分析了气体膜分离过程中原料气流量控制的各种方法;提出通过在尾气侧安装调节阀来定量调节原料气流量的控制方法;该方法成功应用于金陵石化加氢裂化低分气中提取高浓氢的工艺中,验证了这种控制策略的正确性和有效性;整体的控制方案又进一步提高了膜分离装置的操作柔性及适应能力;该方法可同时保证渗透气快气浓度及回收率的性能指标,适用于所有气体膜分离过程中对处理气量的自动控制.  相似文献   
999.
The Pr α-sialon powders prepared by self-propagating high-temperature synthesis (SHS), consisting of 55 wt% Pr α-sialon and 45 wt% of β-sialon (abbreviated as α' and β'), were hot-pressed at 1800°C for 1 h. The results showed that Pr α' phase would transfer to β' with the appearance of JEM phase (Pr(Si6− z Al z )(N10− z O z )) after sintering, thus resulting in the increase of β' phase to 86 wt%. The addition of Y2O3 into SHS-ed Pr α' powders as the starting materials restrains the transformation of α' to β' and prevents the formation of JEM phase as well. The nucleation mechanism of Pr α' grain during hot-pressing was investigated in terms of transmission electron microscope and energy-dispersive spectrometer analysis. Two nucleation modes of Pr α' grains were found, i.e., nucleating on the undissolved Pr α' grains and on the nuclei of (Pr, Y) α' grains precipitated from liquid phase.  相似文献   
1000.
刘成  刘桉 《泥沙研究》2017,(4):73-80
在全球变化等多种因素的影响下,许多流域的泥沙问题严重,泥沙管理的重要性日益突出。通过对联合国教科文组织国际泥沙计划所开展的案例研究进行综述,认识到自然地理特征、社会经济条件、水利工程建设对流域产沙、输沙和水资源利用有重要影响。土壤侵蚀加速、水库淤积、下游输沙量减少和生态平衡破坏是目前全球各大流域面临的主要问题。综合各项案例,研究泥沙管理技术,提出流域综合泥沙管理的策略,包括水库淤积管理、推移质泥沙管理、土地管理和水土保持等技术手段,以及法律、行政和组织措施。  相似文献   
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