Efficient Multi-User Keyword Search over Encrypted Data in Cloud Computing

As cloud computing becomes prevalent, more and more sensitive information are being centralized into the cloud. For the protection of data privacy, sensitive data usually have to be encrypted before outsourcing, which makes effective data utilization a very challenging task. In this paper, we propose a new method to enable effective fuzzy keyword search in a multi-user system over encrypted cloud data while maintaining keyword privacy. In this new system, differential searching privileges are supported, which is achieved with the technique of attribute-based encryption. Edit distance is utilized to quantify keywords similarity and develop fuzzy keyword search technique, which achieve optimized storage and representation overheads. We further propose a symbol-based trie-traverse searching scheme to improve the search efficiency. Through rigorous security analysis, we show that our proposed solution is secure and privacy-preserving, while correctly realizing the goal of fuzzy keyword search with multiple users

Development of European Small and Medium Sized Enterprises for Reference in China

The small and medium sized enterprises which are predominantly economic superior in the European small countries mainly produce, process, import and export advanced technical products with high added value and scientific content. They facilitate the development of the economy through technical creation, which is also benefited from the highly efficient economy system established cooperatively by government, bank, and non-government organizations. The experience in Europe provides instructive reference for the development of middle and small sized enterprises in China. Key words: small and medium sized enterprises; economy with high efficiency; reference Résumé: Le nombre des PME occupe une place prépondérante dans l’économie européenne. La plupart d’entre elles se spécialisent dans la production, dans la transformation et dans l'importation et l'exportation des produits de haute valeur ajoutée, ou de haute technologie. Elles s'appuient sur l'innovation technologique afin de promouvoir le développement économique. Une économie efficace fondée sur la base d’une coopération étroite entre le gouvernement, les banques, les organisations non gouvernementales a jouéégalement un rôle très important. Le succès de l'expérience européenne est une référence utile pour le développement des PME en Chine. Mots-clés: PME; économie efficace; références 摘 要：歐洲小國經濟中數量占絕對優勢的中小企業以生產、加工和進出口附加值高、科技含量大的高新技術產 品為主，並依靠技術創新推動經濟發展，政府、銀行、非政府機構密切合作建立起的高效率經濟也起了極大的促 進作用。歐洲的成功經驗給中國中小企業發展提供了有益借鑒。 關鍵詞： 中小企業；高效率經濟；借

Proper Scaling of the Anomalous Hall Effect

Working with epitaxial films of Fe, we succeeded in independent control of different scattering processes in the anomalous Hall effect. The result appropriately accounted for the role of phonons, thereby clearly exposing the fundamental flaws of the standard plot of the anomalous Hall resistivity versus longitudinal resistivity. A new scaling has been thus established that allows an unambiguous identification of the intrinsic Berry curvature mechanism as well as the extrinsic skew scattering and side-jump mechanisms of the anomalous Hall effect.Comment: 5 pages, 4 figure

Multivariable Scaling for the Anomalous Hall Effect

We derive a general scaling relation for the anomalous Hall effect in ferromagnetic metals involving multiple competing scattering mechanisms, described by a quadratic hypersurface in the space spanned by the partial resistivities. We also present experimental findings, which show strong deviation from previously found scaling forms when different scattering mechanism compete in strength but can be nicely explained by our theory

Evidence of the side jump mechanism in the anomalous Hall effect in paramagnets

Persistent confusion has existed between the intrinsic (Berry curvature) and the side jump mechanisms of anomalous Hall effect (AHE) in ferromagnets. We provide unambiguous identification of the side jump mechanism, in addition to the skew scattering contribution in epitaxial paramagnetic Ni$_{34}$Cu$_{66}$ thin films, in which the intrinsic contribution is by definition excluded. Furthermore, the temperature dependence of the AHE further reveals that the side jump mechanism is dominated by the elastic scattering

Orbital angular momentum mode-demultiplexing scheme with partial angular receiving aperture

For long distance orbital angular momentum (OAM) based transmission, the conventional whole beam receiving scheme encounters the difficulty of large aperture due to the divergence of OAM beams. We propose a novel partial receiving scheme, using a restricted angular aperture to receive and demultiplex multi-OAM-mode beams. The scheme is theoretically analyzed to show that a regularly spaced OAM mode set remain orthogonal and therefore can be de-multiplexed. Experiments have been carried out to verify the feasibility. This partial receiving scheme can serve as an effective method with both space and cost savings for the OAM communications. It is applicable to both free space OAM optical communications and radio frequency (RF) OAM communications