Personal digital resources now tend to be stored, managed and shared using a variety of devices and online services. As a result, different versions of resources are often stored in different places, and it has become increasingly difficult for users to keep track of them. We introduce the concept of a file history graph that can be used to provide users with a global view of resource provenance and enable them to track specific versions across devices and services. We describe how this has been used to realise a version-aware environment, called Memsy, and report on a lab study used to evaluate the proposed workflow. We also describe how reconciliation services can be used to fill in missing links in the file history graph and present a detailed study for the case of images as a proof of concept.
In this paper, we propose Partition min-Hash (PmH), a novel hashing scheme for discovering partial duplicate images from a large database. Unlike the standard min-Hash algorithm that assumes a bag of words image representation, our approach utilizes the fact that duplicate regions among images are often localized. By theoretical analysis, simulation, and empirical study, we show that PmH outperforms standard min-Hash in terms of precision and recall, while being orders of magnitude faster. When combined with the start-of-the-art Geometric min-Hash algorithm, our approach speeds up hashing by 10 times without losing precision or recall. When given a fixed time budget, our method achieves much higher recall than the state-of-the-art.
Challenging the views of human rights activists, Stoll argues that the Ixils who supported Guatemalan rebels in the early 1980's did so because they were caught in the crossfire between the guerillas and the army, not because revolutionary violence expressed community aspirations.