雾天环境下自适应图像增强去雾方法研究

由于雾天环境下大气散射现象,拍摄出来的景物能见度和对比度会大幅降低.为了解决问题,提出了一种针对雾天环境的自适应图像增强去雾方法,部分重叠直方图均衡化方法(POSHE).方法将邻域内的子块变换函数通过加权求和计算得到当前子块的变换函数,以消除子块直方图均衡化变换之间的差异,对于图像场景深度信息多变且未知的雾天图像能够突出图像的局部细节信息,达到良好的去雾效果,并能够满足实时视频图像处理的要求.     

A verifiable data integrity scheme for distributed data sharing in fog computing architecture

Fog computing is a promising computing paradigm that brings computing resources close to end users at the edge of the network. Hence, it handles large-scale, geographically distributed, and latency-sensitive services. However, there are several security challenges that must be addressed due to the unreliable nature of this architecture. One can cite the verification of data integrity among the most critical issues in the context of fog computing. In fact, since data is often stored dynamically in a fully distributed manner, traditional solutions based on a centralized third-party auditor for integrity verification become unsuitable for such highly dynamic and distributed contexts. Indeed, the constant transfer of data to and from the central auditor results in high network latency and potential bottlenecks.Therefore, in this paper, we propose a new efficient public verification protocol that ensures the integrity of the data in fog computing architecture. Our solution protects data integrity and authenticity using the short integer solution problem (SIS) and identity-based signatures. Moreover, in order to legitimately modify the data, our protocol allows to distributively identify the data owners and to delegate their signatures to other entities in the architecture. Furthermore, it enables effective data integrity verification even when data is separately shared across several servers. This verification can be performed by any legitimate end user connected to the architecture, and without relying on any trusted third party. Finally, we prove that our protocol is highly efficient and outperforms existing solutions, as demonstrated by our extensive simulations and thorough security analysis that confirmed its security.     

What Has Happened to Territory?

In the concluding article of the main section of this issue, Antoine Picon evokes the earlier meaning of territory for administrators, architects and engineers, as lands that were integrated into nations or colonies by the early modern European countries. Picon traces how 18th- and 19th-century perceptions of territory with an emphasis on administrative separation fed into an attitude of both distance and sensitivity to landscape, as exemplified by the Romantic movement in painting and literature; a heritage that continued into the 20th century in architecture with its emphasis on rationalisation. Copyright © 2010 John Wiley & Sons, Ltd.